transforming-growth-factor-beta and Proteinuria

Vitamin D has been suggested to harbor multiple biological activities, among them the potential of vitamin D in the protection of diabetic nephropathy (DN) has attracted special attention. Both animal studies and clinical trials have documented an inverse correlation between low vitamin D levels and DN risk, and supplementation with vitamin D or its active derivatives has been demonstrated to improve endothelial cell injury, reduce proteinuria, attenuate renal fibrosis, and resultantly retard DN progression. Vitamin D exerts its pharmacological effects primarily via vitamin D receptor, whose activation inhibits the renin-angiotensin system, a key culprit for DN under hyperglycemia. The anti-DN benefit of vitamin D can be enhanced when administrated in combination with angiotensin converting enzyme inhibitors or angiotensin II receptor blockers. Mechanistic studies reveal that pathways relevant to inflammation participate in the pathogenesis of DN, however, consumption of vitamin D-related products negatively regulates inflammatory response at multiple levels, indicated by inhibiting macrophage infiltration, nuclear factor-kappa B (NF-κB) activation, and production of such inflammatory mediators as transforming growth factor-β(TGF-β), monocyte chemoattractant protein 1(MCP-1), and regulated upon activation normal T cell expressed and secreted protein(RANTES). The robust anti-inflammatory property of vitamin D-related products allows them with a promising renoprotective therapeutic option for DN. This review summarizes new advances in our understanding of vitamin D-related products in the DN management.

Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Chemokine CCL2; Chemokine CCL5; Diabetic Nephropathies; Drug Therapy, Combination; Endothelial Cells; Humans; NF-kappa B; Protective Agents; Proteinuria; Receptors, Calcitriol; Renin-Angiotensin System; Transforming Growth Factor beta; Vitamin D

Chronic kidney disease (CKD) has a very high mortality rate and remains a global health challenge. Inhibiting renal fibrosis is one of the most promising therapeutic strategies for CKD. Recent studies have indicated that endoplasmic reticulum stress (ERS) serves an active role in the development of acute and chronic kidney disease, especially with regards to renal fibrosis. In the current review, the authors summarize the latest understanding of the role of ERS during the onset of renal fibrosis. ERS promotes renal fibrosis through multiple signaling pathways, such as transforming growth factor‑β, epithelial‑mesenchymal transition and oxidative stress. In addition, ERS also causes podocyte damage, leading to increased proteinuria and the development of renal fibrosis in rat models. In conclusion, targeted inhibition of ERS may become a promising therapeutic strategy for renal fibrosis.

Topics: Animals; Endoplasmic Reticulum Stress; Epithelial-Mesenchymal Transition; Fibrosis; Humans; Kidney; Proteinuria; Transforming Growth Factor beta

Autophagy is a highly conserved homoeostatic mechanism for cell survival under conditions of stress, and is widely implicated as an important pathway in many biological processes and diseases. In progressive kidney diseases, fibrosis represents the common pathway to end-stage kidney failure. Transforming growth factor-β1 (TGF-β1) is a pleiotropic cytokine that has been established as a central mediator of kidney fibrosis. A recently emerging body of evidence from studies in renal cells in culture and experimental animal models suggests that TGF-β1 regulates autophagy and that autophagy regulates many critical aspects of normal and disease conditions associated with kidney fibrosis, such as tubulointerstitial fibrosis, glomerulosclerosis, and diabetic nephropathy. Here, we review the recent advances exploring the process of autophagy, its regulation by TGF-β1, and the implication in the pathogenesis of progressive kidney fibrosis and injury responses. Understanding the cellular and molecular bases of this process is crucial for identifying potential new diagnostic and therapeutic targets of kidney fibrosis.

Topics: Animals; Autophagy; Diabetic Nephropathies; Fibrosis; Humans; Kidney; Kidney Tubules; Mesangial Cells; Proteinuria; Signal Transduction; Transforming Growth Factor beta

The glomerular capillary endothelium is highly specialized to support the selective filtration of massive volumes of plasma. Filtration is driven by Starling forces acting across the glomerular capillary wall, and depends on its large surface area and extremely high water permeability. Glomerular endothelial cells are extremely flat and perforated by dense arrays of trans-cellular pores, the fenestrae. This phenotype is critical for the high glomerular water permeability and depends on podocyte-derived VEGF, as well as TGF-beta. Endothelial cell-derived PDGFB, in turn, is necessary for the establishment of mesangial cells, which sculpt the glomerular loop structure that underlies the large filtration surface area. In pre-eclampsia, inhibition of the VEGF- and TGF-beta signaling pathways leads to endothelial swelling and loss of fenestrae, reducing the glomerular filtration rate. Similarly, in the thrombotic microangiopathies, glomerular endothelial cell injury coupled with inappropriate VWF activation leads to intracapillary platelet aggregation and loss of the flat, fenestrated phenotype, thus reducing the glomerular filtration rate. Normally, a remarkably small fraction of albumin and other large plasma proteins passes across the glomerular capillary wall despite the massive filtration of water and small solutes. An elaborate glycocalyx, which covers glomerular endothelial cells and their fenestrae forms an impressive barrier that, together with other components of the glomerular capillary wall, prevents loss of plasma proteins into the urine. Indeed, microalbuminuria is a marker for endothelial glycocalyx disruption, and most forms of glomerular endothelial cell injury including pre-eclampsia and thrombotic microangiopaties can cause proteinuria.

Topics: Albuminuria; Animals; Endothelium, Vascular; Glomerular Filtration Rate; Humans; Kidney Glomerulus; Permeability; Proteinuria; Purpura, Thrombotic Thrombocytopenic; Transforming Growth Factor beta

Microalbuminuria is the earliest detectable clinical abnormality in diabetic glomerulopathy. On a molecular level, metabolic pathways activated by hyperglycemia, glycated proteins, hemodynamic factors, and oxidative stress are key players in the genesis of diabetic kidney disease. A variety of growth factors and cytokines are then induced through complex signal transduction pathways. Transforming growth factor-beta 1 (TGF-beta1) has emerged as an important downstream mediator for the development of renal hypertrophy and the accumulation of mesangial extracellular matrix components, but there is limited evidence to support its role in the development of albuminuria. The loss of proteoglycans in the glomerular basement membrane (GBM) has been recently questioned as causative of the albuminuria, and current research has focused on the podocyte as a central target for the effects of the metabolic milieu in the development and progression of diabetic albuminuria. Podocyte-derived vascular endothelial growth factor (VEGF), a permeability and angiogenic factor whose expression is increased in diabetic kidney disease, is perhaps a major mediator of the increased protein filtration. Decreased podocyte number and/or density as a result of apoptosis or detachment, GBM thickening with altered matrix composition, and a reduction in nephrin protein in the slit diaphragm with podocyte foot process effacement, all comprise the principal features of diabetic podocytopathy that clinically manifests as albuminuria and proteinuria. Many of these events are mediated by angiotensin II whose local concentration is stimulated by high glucose, mechanical stretch, and proteinuria itself. Angiotensin II in turn stimulates podocyte-derived VEGF, suppresses nephrin expression, and induces TGF-beta1 leading to podocyte apoptosis and fostering the development of glomerulosclerosis. Proteinuria can then induce in tubular cells a genetic program leading to tubulointerstitial inflammation, fibrosis and tubular atrophy. Besides direct effects of albuminuria on tubular cells, pathophysiological changes in the ultrafiltration barrier lead to an increased tubular filtration of various growth factors (TGF-beta1, insulin-like growth factor I) that may further alter the function of tubular cells. Moreover, angiotensin II also stimulates uptake of ultrafiltered proteins into tubular cells and enhances the production of proinflammatory and profibrotic cytokines within the cells. Migration of macro

Topics: Angiotensin II; Diabetic Nephropathies; Endothelial Cells; Endothelium, Vascular; Humans; Kidney Glomerulus; Membrane Proteins; Models, Biological; Podocytes; Proteinuria; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

Diabetic nephropathy characterized by proteinuria and sclerosis is the leading cause of renal failure, but its mechanisms are not well understood. Zucker Obese (ZO) rat model of obesity, insulin resistance, and hypertension has been used to study nephropathy. We hypothesize that chronically elevated intrarenal angiotensin II (ANG II) down-regulates nephrin, a key slit-pore protein and up-regulates fibrogenic molecule transforming growth factor (TGFbeta1) and thus result in progression of nephropathy in type 2 diabetes. Untreated or angiotensin converting enzyme (ACE) inhibitor, captopril, treated ZO and control Lean (ZL) rats were used to measure intrarenal levels of ANG II, glomerular nephrin, TGFbeta1, collagen and fibronectin with age using radioimmunoassay, RT-PCR and immunoblot techniques. Progression of nephropathy was established by measuring proteinuria and sclerosis. ZO rats developed obesity, hyperglycemia, hyperinsulinimia, increase in intrarenal ANG II and proteinuria. Expression of glomerular nephrin decreased while expression of TGFbeta1 and matrix components increased in ZO rats. Captopril treatment prevented increase in intrarenal ANG II, and reversed expression of nephrin, TGFbeta1, collagen and fibronectin. We conclude that in this model of type 2 diabetic nephropathy, chronically elevated intrarenal ANG II causes proteinuria via decrease in nephrin and glomerulosclerosis via TGFbeta1 mediated increase in matrix component.

Topics: Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Animals; Animals, Genetically Modified; Blood Pressure; Chromatography; Collagen; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Fibronectins; Glucose; Hyperglycemia; Immunoblotting; Insulin; Insulin Resistance; Kidney; Male; Models, Statistical; Obesity; Proteinuria; Radioimmunoassay; Rats; Rats, Zucker; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1; Up-Regulation

Despite the renoprotective effects of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs), many patients with chronic kidney disease develop end-stage kidney disease. Combination treatment with an ACEI and an ARB is a recently introduced approach to obtain more complete blockade of the renin-angiotensin system, based on the different mechanisms of action of the two classes of drug. To assess the shortcomings of single treatment with ACEIs and ARBs, and the potential benefits of combination treatment, we reviewed the experimental and clinical evidence suggesting that combination treatment offers more complete blockade of the renin-angiotensin system and identified areas in which further research is necessary to confirm the benefits of combination treatment. The available data suggest that combination treatment with an ACEI and an ARB has a greater renoprotective effect than either drug alone. In addition, more recent data have shown that combination treatment is more potent in suppressing renal fibrosis, and is well tolerated in patients with advanced chronic kidney disease. Clinical trials with rigorous endpoints are needed to further establish the benefits of combination treatment in renal protection.

Topics: Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Chronic Disease; Diabetic Nephropathies; Drug Therapy, Combination; Humans; Kidney Diseases; Proteinuria; Transforming Growth Factor beta; Transforming Growth Factor beta1

There are ongoing debates as to the role and mechanisms of proteinuria in tubulointerstitial fibrogenesis. Moreover, recent experimental findings have allowed for further insights into mediators and interactions between cells in the renal interstitium during fibrogenesis.. Proteinuria or albuminuria are likely just markers for the glomerular ultrafiltration and tubular actions of ultrafiltered, biologically active growth factors which 'activate' tubular cells causing basolateral secretion of chemokines and cytokines. Chemokines attract and activate macrophages. Tubular cell-derived platelet-derived growth factor (PDGF) and macrophage-derived transforming growth factor-beta cause fibroblast proliferation. Several growth factors contribute to their transition into extracellular matrix-producing myofibroblasts. This cascade of events provides targets for some currently available and several novel therapies.. Albuminuria or glomerular proteinuria appear to be markers but ultrafiltered, bioactive growth factors are culprits in proteinuria-associated interstitial fibrosis. Interactions of tubular cells with macrophages and fibroblasts in the interstitium via defined growth factor/cytokines provide opportunities for therapeutic interventions.

Topics: Growth Substances; Humans; Kidney Tubules; Macrophages; Nephritis, Interstitial; Platelet-Derived Growth Factor; Proteinuria; Transforming Growth Factor beta

During the last decade, therapeutic measures based on inhibitors of the angiotensin I converting enzyme have proved to have some efficacy in the prevention of renal fibrosis. This review is devoted to new anti-fibrotic strategies aimed at inhibiting reabsorption by proximal tubule cells of filtrated proteins, preventing transdifferentiation of proximal tubule cells, inhibiting the pro-inflammatory effects of angiotensin II and endothelin, blocking TGF beta, and limiting renal ischaemia. Furthermore, experimental models and clinical reports have shown that renal fibrosis could regress, which has important therapeutic implications. The design of new preventive and curative treatments should be accompanied by the identification of urinary and serum markers of the various stages of renal fibrosis.

Topics: Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Animals; Biomarkers; Endothelins; Humans; Ischemia; Kidney; Kidney Failure, Chronic; Kidney Tubules, Proximal; Mice; Models, Animal; Proteinuria; Rats; Sclerosis; Transforming Growth Factor beta

Tubulointerstitial injury caused by multiple insults, including significant proteinuria, results in interstitial inflammation. Evidence supports the hypothesis that interstitial inflammatory cells initially recruited in response to injury subsequently contribute to interstitial fibrosis. Experimental manipulations that decrease the number of interstitial macrophages (Mphis) preserve renal function. Mphis have the potential to secrete a large number of products, including some with fibrosis-promoting effects. Their most potent profibrotic effect may be the production of soluble fibrogenic factors, such as transforming growth factor-ss, endothelin-1, and tumor necrosis factor-alpha. These factors stimulate the synthesis of extracellular matrix proteins by neighboring myofibroblasts. Mphis may also release inhibitors of such matrix-degrading proteases as tissue inhibitor of metalloproteinase-1 and plasminogen activator inhibitor-1. Protease inhibitors have a role in renal scarring by impairing the process of matrix remodeling and degradation, which normally functions in parallel with matrix synthesis. It is predicted that therapeutic interventions that dampen the interstitial inflammatory response will attenuate the renal fibrogenic response, preserving normal renal architecture and function.

Topics: Animals; Disease Progression; Endothelin-1; Fibrosis; Humans; Kidney; Kidney Diseases; Macrophages; Plasminogen Activator Inhibitor 1; Proteinuria; Tissue Inhibitor of Metalloproteinase-1; Transforming Growth Factor beta

Emerging data on the role of interstitial inflammation in progressive renal disease are redefining our understanding of the pathogenic mechanisms of chronic kidney damage. Recent experimental evidence emphasizes the role for both immune and non-immune mechanisms in interstitial nephritis. New observations regarding maneuvers that downregulate such injurious renal responses may direct further studies that develop new therapeutic modalities.

Topics: Angiotensin II; Animals; Antibody Formation; B-Lymphocytes; Chemokines; Disease Models, Animal; Humans; Immune Tolerance; Immunity, Cellular; Interferon-gamma; Kidney Tubules; Nephritis, Interstitial; Nitric Oxide; Proteinuria; Transforming Growth Factor beta

Diabetic nephropathy (DN) is characterized structurally by progressive mesangial deposition of extracellular matrix (ECM). Transforming growth factor-ss (TGF-ss) is considered to be one of the major cytokines involved in the regulation of ECM synthesis and degradation. Several studies suggest that an increase in urinary TGF-ss levels may reflect an enhanced production of this polypeptide by the kidney cells. We evaluated TGF-ss in occasional urine samples from 14 normal individuals and 23 patients with type 2 diabetes (13 with persistent proteinuria >500 mg/24 h, DN, 6 with microalbuminuria, DMMA, and 4 with normal urinary albumin excretion, DMN) by enzyme immunoassay. An increase in the rate of urinary TGF-ss excretion (pg/mg U Creat.) was observed in patients with DN (296.07 +/- 330.77) (P<0.001) compared to normal individuals (17.04 +/- 18.56) (Kruskal-Wallis nonparametric analysis of variance); however, this increase was not observed in patients with DMMA (25.13 +/- 11.30) or in DMN (18.16 +/- 11.82). There was a positive correlation between the rate of urinary TGF-ss excretion and proteinuria (r = 0.70, alpha = 0.05) (Pearson's analysis), one of the parameters of disease progression.

Topics: Adult; Biomarkers; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Extracellular Matrix; Humans; Kidney; Middle Aged; Proteinuria; Transforming Growth Factor beta

Aliskiren is a relatively new oral direct renin inhibitor (DRI) that has been increasingly used for the treatment of diabetic nephropathy and hypertension. Its potential efficacy in nondiabetic chronic kidney diseases that are driven by renin-angiotensin system activation remains to be explored.. From a teaching and regional hospital in Hong Kong between July 2009 and March 2010, patients with biopsy-proven immunoglobulin A nephropathy (IgAN) in whom the ratio of protein to creatinine, as measured in early morning urine samples, remained >113 mg/mmol (1000 mg/g), despite receiving the maximum recommended dose of losartan (100 mg daily) were recruited to receive additional DRI treatment. They were followed prospectively for 12 months with changes in proteinuria as the main outcome measure.. Twenty-five consecutive patients were enrolled. Treatment with aliskiren for 12 months reduced the mean urinary protein-to-creatinine ratio by 26.3% (95% confidence interval, 20.1-43.6; P = 0.001 versus baseline), with a reduction of ≥ 50% in 24% of patients. There were significant reductions in plasma renin activity (P < 0.0001) and serum interleukin-6 (P < 0.05) and transforming growth factor-β (P = 0.01) levels, compared with baseline. Two patients (8%) developed mild allergic reactions and six (24%) had transient hyperkalemia (K >5.5 mmol/L) during the study.. Aliskiren confers an antiproteinuric effect in IgAN patients with significant residual proteinuria, despite receiving the recommended renoprotective treatment. Further prospective randomized trials are warranted to examine its long-term renoprotective potential. This trial is registered with the ClinicalTrials.gov number NCT00922311.

Topics: Adult; Amides; Antihypertensive Agents; Confidence Intervals; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Therapy, Combination; Female; Follow-Up Studies; Fumarates; Glomerulonephritis, IGA; Hong Kong; Humans; Interleukin-6; Kidney Function Tests; Losartan; Male; Middle Aged; Odds Ratio; Pilot Projects; Prospective Studies; Proteinuria; Risk Assessment; Severity of Illness Index; Time Factors; Transforming Growth Factor beta; Treatment Outcome; Urinalysis

Primary focal segmental glomerulosclerosis (FSGS) is a disease with poor prognosis and high unmet therapeutic need. Here, we evaluated the safety and pharmacokinetics of single-dose infusions of fresolimumab, a human monoclonal antibody that inactivates all forms of transforming growth factor-β (TGF-β), in a phase I open-label, dose-ranging study. Patients with biopsy-confirmed, treatment-resistant, primary FSGS with a minimum estimated glomerular filtration rate (eGFR) of 25  ml/min per 1.73  m(2), and a urine protein to creatinine ratio over 1.8  mg/mg were eligible. All 16 patients completed the study in which each received one of four single-dose levels of fresolimumab (up to 4  mg/kg) and was followed for 112 days. Fresolimumab was well tolerated with pustular rash the only adverse event in two patients. One patient was diagnosed with a histologically confirmed primitive neuroectodermal tumor 2 years after fresolimumab treatment. Consistent with treatment-resistant FSGS, there was a slight decline in eGFR (median decline baseline to final of 5.85 ml/min per 1.73  m(2)). Proteinuria fluctuated during the study with the median decline from baseline to final in urine protein to creatinine ratio of 1.2  mg/mg with all three Black patients having a mean decline of 3.6  mg/mg. The half-life of fresolimumab was ∼14 days, and the mean dose-normalized Cmax and area under the curve were independent of dose. Thus, single-dose fresolimumab was well tolerated in patients with primary resistant FSGS. Additional evaluation in a larger dose-ranging study is necessary.

Topics: Adult; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Biomarkers; Biopsy; Creatinine; Dose-Response Relationship, Drug; Europe; Female; Glomerular Filtration Rate; Glomerulosclerosis, Focal Segmental; Humans; Infusions, Parenteral; Kidney; Male; Middle Aged; Proteinuria; Transforming Growth Factor beta; Treatment Outcome; United States; Young Adult

End-stage renal disease (ESRD) due to type 2 diabetic nephropathy is a very common condition which is increasing in prevalence, and is associated with high global levels of mortality and morbidity. Both proteinuria and transforming growth factor-β (TGF-β) may contribute to the development of ESRD in patients with diabetic nephropathy. Experimental studies indicate that turmeric improves diabetic nephropathy by suppressing TGF-β. Therefore, this study investigated the effects of turmeric on serum and urinary TGF-β, interleukin-8 (IL-8) and tumour necrosis factor-α (TNF-α), as well as proteinuria, in patients with overt type 2 diabetic nephropathy.. A randomized, double-blind and placebo-controlled study was carried out in the Diabetes Clinic of the Outpatient Department of Shiraz University of Medical Sciences on 40 patients with overt type 2 diabetic nephropathy, randomized into a trial group (n = 20) and a control group (n = 20). Each patient in the trial group received one capsule with each meal containing 500 mg turmeric, of which 22.1 mg was the active ingredient curcumin (three capsules daily) for 2 months. The control group received three capsules identical in colour and size containing starch for the same 2 months.. Serum levels of TGF-β and IL-8 and urinary protein excretion and IL-8 decreased significantly comparing the pre- and post-turmeric supplementation values. No adverse effects related to turmeric supplementation were observed during the trial.. Short-term turmeric supplementation can attenuate proteinuria, TGF-β and IL-8 in patients with overt type 2 diabetic nephropathy and can be administered as a safe adjuvant therapy for these patients.

Topics: Administration, Oral; Curcuma; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dietary Supplements; Double-Blind Method; Female; Humans; Interleukin-8; Male; Middle Aged; Phytotherapy; Proteinuria; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Proteinuria and dyslipidemia are nonimmune risk factors implicated in the deterioration of kidney function and associated with an increased risk of accelerated atherogenesis. Statin therapy, used for cholesterol reduction, has shown a renoprotective effect in animal models, particularly in cases of proteinuria. This may occur through lipid-independent mechanisms, such as improved endothelial dysfunction/vascular biology, reduced inflammatory cytokine production (transforming growth factor-beta 1 [TGF-beta1]), and regulation of fibrogenic responses. We studied mechanisms of action of agents, such as statins, to change proteinuria, inflammatory parameters, and TGF-beta1 plasma levels in relation to vascular tone.. Fifty-six kidney transplant recipients (30 men and 26 women of overall mean age 54 +/- 13 years) were treated posttransplantation with atorvastatin (10 mg/d) for 12 weeks without renin-angiotensin-system blockade drugs. Inflammatory variables, biochemical parameters, lipid profile, renal function, and TGF-beta1 levels were determined at baseline and at 3 months. Vascular stiffness was evaluated using pulse wave velocity (PWV).. Baseline TGF-beta1 plasma levels were higher among transplant recipients than healthy controls, namely 8.12 ng/mL (range, 5.82-13.12) to 2.55 (range, 1.78- 4.35) (P < .01). Furthermore, the levels remained higher after the treatment with atorvastatin, namely, 7.59 (range, 4.97-12.35) to 2.55 (range, 1.78-4.35) ng/mL (P < .01). Atorvastatin treatment significantly decreased total cholesterol as well as low-density lipoprotein cholesterol plasma levels, but did not modify mean blood pressure (MBP), proteinuria, creatinine clearance, or inflammatory factors. Reduction in TGF-beta1 plasma levels was statistically significant among patients with PWV >9.75 (m/s) (pathology reference value) namely, from 10.7 ng/mL (range, 7.02-13.98) to 6.7 (range, 3.96-11.94) (P = .038). Among older patients, atorvastatin significantly decrease TGF-beta1 plasma levels: from 9.5 ng/mL (range, 6.45-14.44) to 5.65 (range, 3.63-9.48; P < .05). The decreased TGF-beta1 was not related to changes in lipid profiles.. Atorvastatin (10 mg/d) improved the lipid profile and moreover among older patients with worse PWV (>9.75 m/s), TGF-beta1 levels were significantly reduced. Our results suggested that statins displayed potent actions distinct from their hypolipidemic effects.

Topics: Adult; Aged; Atorvastatin; Blood Pressure; Cohort Studies; Dyslipidemias; Female; Glomerular Filtration Rate; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertension; Immunosuppressive Agents; Kidney Transplantation; Male; Middle Aged; Postoperative Complications; Proteinuria; Pyrroles; Transforming Growth Factor beta

Renin-angiotensin system inhibition is a widely accepted approach to initially deal with proteinuria in IgA nephropathy, while the role of immunosuppressants remains controversial in many instances. A prospective, uncontrolled, open-label trial was undertaken in patients with biopsy-proven IgA nephropathy with proteinuria > 0.5 g/day and normal renal function to assess the efficacy of a combination treatment of angiotensin converting enzyme inhibitors plus angiotensin receptor blockers enalapril valsartan coupled with methylprednisone to decrease proteinuria to levels below 0.5 g/day. Twenty patients were included: Age 37.45 +/- 13.26 years (50% male); 7 patients (35%) were hypertensive; proteinuria 2.2 +/- 1.86 g/day; serum creatinine 1.07 +/- 0.29 mg/dl; mean follow-up 60.10 +/- 31.47 months. IgA nephropathy was subclassified according to Haas criteria. Twelve patients (60%) were class II; seven (35%) were class III and one (5%) class V. All patients received dual renin-angiotensin system blockade as tolerated. Oral methylprednisone was started at 0.5 mg/kg/day for the initial 8 weeks and subsequently tapered bi-weekly until the maintenance dose of 4 mg was reached. Oral steroids were discontinued after 24 weeks (6 months) of therapy but renin-angiotensin inhibition remained unchanged. At 10 weeks of therapy proteinuria decreased to 0.15 +/- 0.07 g/day (P < 0.001) while serum creatinine did not vary: 1.07 +/- 0.28 mg/dl (P = ns). After a mean follow-up of 42.36 +/- 21.56 months urinary protein excretion (0.12 +/- 0.06 g/day) and renal function (serum creatinine 1.06 +/- 0.27 mg/dl) remained stable. No major side effects were reported during the study. Renin-angiotensin blockade plus oral steroids proved useful to significantly decrease proteinuria to < 0.5 g/day in patients with IgA nephropathy without changes in renal function.

Topics: Administration, Oral; Adult; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Creatinine; Drug Therapy, Combination; Female; Follow-Up Studies; Glomerulonephritis, IGA; Glucocorticoids; Humans; Hypertension; Male; Prednisolone; Prospective Studies; Proteinuria; Renin-Angiotensin System; Transforming Growth Factor beta

Increased urinary excretion of protein and transforming growth factor-beta (TGF-beta) are associated with progression of diabetic nephropathy (DN). Thiazolidinediones (TZD) could reduce urinary protein excretion in patients with microalbuminuric DN. There is little data of patients with macroalbuminuric DN. Also, there are no available clinical data regarding the effect of TZD on TGF-beta and type IV collagen in clinical DN. The present study was carried out to evaluate the effect of pioglitazone (PGZ), a member of TZD, on urinary protein, urinary TGF-beta, and urinary type IV collagen excretion in type 2 diabetic patients with macroalbuminuric DN.. Forty patients with type 2 diabetes and overt nephropathy, proteinuria more than 500 mg/day, were randomly assigned to receive PGZ (30 mg/day, n = 24) or placebo (control group, n = 16), for 12 weeks. Blood pressure, plasma glucose, glycated hemoglobin, lipid profile, 24-hour proteinuria, urinary TGF-beta and urinary type IV collagen were determined and compared.. Glycemic control and blood pressure in both groups were not significant different. At baseline, the levels of proteinuria, urinary TGF-beta, and type IV collagen were not significant different between both groups. The geometric mean of urinary protein excretion in the PGZ group was progressively reduced from 1.64 to 0.98 gram/day (g/d), or 40.1% decrease which was significantly different (p < 0.05) from the 4.3% increase (from 1.72 to 1.80 g/d) in the control group. Urinary TGF-beta excretion in the PGZ group was decreased by 47.8% which significantly differed from the 59.7% increase in the control group (p < 0.05). Urinary type IV collagen levels in the PGZ group were decreased by 35% which was slightly, but not significantly, different from the 51.6% elevation in the control group (p = 0.06).. Besides the effectiveness in blood sugar control, pioglitazone could salutarily reduce proteinuria and synthesis of TGF-beta as well as type IV collagen. These beneficial effects of pioglitazone on diabetic nephropathy are comparable to angiotensin converting enzyme inhibitors and angiotensin receptor blockers

Topics: Administration, Oral; Aged; Blood Glucose; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dose-Response Relationship, Drug; Female; Humans; Hypoglycemic Agents; Kidney Function Tests; Male; Middle Aged; Pioglitazone; Probability; Proteinuria; Reference Values; Risk Assessment; Sensitivity and Specificity; Severity of Illness Index; Single-Blind Method; Thiazolidinediones; Transforming Growth Factor beta; Treatment Outcome

In this study we evaluated the effect of a dual blockade with enalapril and losartan on the reduction of overt macroproteinuria and its potential mechanism(s) in hypertensive patients with type 2 diabetes. Twenty-six hypertensive patients with type 2 diabetes at the baseline were administered 5 mg of enalapril once daily for 12 weeks. At the beginning of the study, the subjects were assigned to receive an add-on of 50 mg of losartan once daily or 5 mg of enalapril once daily for another 12 weeks. Blood samples were collected at the baseline, at the beginning, and at the end of the study for the measurement of laboratory parameters, and these data, including blood pressure, were compared between the two groups. Treatment with 5 mg of enalapril significantly decreased the systolic blood pressure level in both groups, and the addition of losartan and/or enalapril further decreased the levels. There was no difference in blood pressure between the two groups. However, the addition of losartan, but not enalapril, significantly decreased the urinary protein excretion level, plasma aldosterone, and hypersensitive-C-reactive protein at the end of the study. The results established that the dual blockade of angiotensin II with enalapril and losartan has a greater clinical benefit for high-risk patients with hypertension and advanced diabetic nephropathy.

Topics: Aged; Aldosterone; Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; C-Reactive Protein; Cystatin C; Cystatins; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Enalapril; Female; Humans; Hypertension; Losartan; Male; Middle Aged; Natriuretic Peptide, Brain; Proteinuria; Transforming Growth Factor beta

Treatment with agents that inhibit the renin-angiotensin system is commonly regarded as a gold standard renoprotective strategy in patients with chronic kidney diseases. For maximum antiproteinuric effect, the dose titration of these agents is recommended. This therapeutic strategy is not used for proteinuric patients who are not able to receive high doses of angiotensin-converting enzyme inhibitor or angiotensin II receptor antagonists.. In patients with primary glomerulonephritis (n=24), a randomized, triple-treatment, triple-period, cross-over study was performed to compare the effects of combined therapy with benazepril 5 mg and losartan 25 mg and monotherapy with either agent alone at a two-fold higher dose on the extent of tubular injury as assessed by alpha1-microglobulin (alpha1-m) excretion and the plasma level of transforming growth factor-beta1 (TGF-beta1).. Combination therapy significantly reduced alpha1-m excretion compared to either agent used alone: 178.29+/-27.36 to 99.63+/-13.03 mg/g creatinine for losartan + benazepril vs 178.29+/-27.36 to 161.59+/-23.22 mg/g creatinine for benazepril alone (p<0.05; ANOVA) and 178.29+/-27.36 to 99.63+/-13.03 mg/g creatinine for losartan + benazepril vs 178.29+/-27.36 to 173.45+/-27.69 mg/g creatinine for losartan alone (p<0.05; ANOVA). There was a significant correlation between change in alpha1-m excretion and reduction in proteinuria (r=0.704; p=0.023). There were no differences in TGF-beta1 level between the studied treatments. Systemic blood pressure reduction did not differ among the therapies.. Combination therapy with angiotensin-converting enzyme inhibitor and angiotensin II subtype 1 receptor antagonists at very small doses may be superior to monotherapy with these agents at higher doses as far as tubular injury is concerned. We speculate that such a therapeutic strategy may be a useful approach for patients who are known not to be capable of receiving optimal renoprotective doses of these regimens.

Topics: Adolescent; Adult; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Benzazepines; Biomarkers; Creatinine; Cross-Over Studies; Dose-Response Relationship, Drug; Drug Therapy, Combination; Enzyme-Linked Immunosorbent Assay; Female; Follow-Up Studies; Humans; Losartan; Male; Membrane Glycoproteins; Middle Aged; Nephelometry and Turbidimetry; Proteinuria; Renin-Angiotensin System; Transforming Growth Factor beta; Transforming Growth Factor beta1; Treatment Outcome; Trypsin Inhibitor, Kunitz Soybean

Chronic allograft nephropathy (CAN) represents an important cause of graft loss after kidney transplantation. TGF-beta1 is a key factor in fibrogenesis, and the angiotensin II receptor antagonist losartan may decrease the intra-graft synthesis of TGF-beta1. The aim of this study was to determine the clinical and molecular effect of losartan in kidney transplant patients (KTPs) with CAN. We studied nine KTPs, after the first year of transplantation, with proteinuria (more than 500 mg/24 h), stable renal function, and histological signs of CAN. Immunosuppression was cyclosporine, azathioprine, and corticoids. Kidney biopsy was performed in all patients at the beginning of the study and 12 weeks after treatment with 50 mg/day of losartan. Quantitation of intra-graft expression of TGF-beta1 was performed in all biopsies, by real-time PCR. After losartan treatment there were no differences in patients' BP and blood creatinine level. The proteinuria significantly dropped to 414.2+/-377 mg/24 h, P=0.001. Intra-graft expression of TGF-beta1 was decreased after treatment. In conclusion, losartan significantly decreases the intra-graft expression of TGF-beta1 and proteinuria in KTPs with CAN.

Topics: Adult; Angiotensin II Type 1 Receptor Blockers; Chronic Disease; Female; Humans; Kidney; Kidney Diseases; Kidney Transplantation; Losartan; Male; Middle Aged; Proteinuria; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1

Transforming growth factor-beta1 (TGF-beta1) is the major profibrotic cytokine involved in many renal diseases, and urinary TGF-beta1 reflects intrarenal TGF-beta1 production. Urinary TGF-beta1 excretion is reported to be significantly increased in patients with immunoglobulin A (IgA) nephropathy. The aim of the present study was to compare the effects of losartan and amlodipine on proteinuria, as well as on serum and urine TGF-beta1 levels in IgA nephropathy patients with hypertension and proteinuria.. The initial 4 week washout period was followed by 12 weeks of active treatment, in which patients were randomized to once-daily treatment with losartan 50 mg (group 1, n=20) or amlodipine 5 mg (group 2, n=16). Urinary protein and TGF-beta1 excretion, serum TGF-beta1 and other clinical parameters were determined at baseline and during 12 weeks of active treatment.. Both treatments controlled blood pressure (BP) to a similar degree, and renal function and other biochemical parameters did not change during the study period. Urinary protein and TGF-beta1 excretions were significantly elevated in IgA nephropathy patients. Losartan significantly reduced urinary protein (from 2.3+/-1.5 g/day at baseline to 1.2+/-1.5 g/day at 12 weeks, P<0.05) and urinary TGF-beta1 excretion (from 31.2+/-14.0 pg/mg creatinine at baseline to 22.1+/-13.5 pg/mg creatinine at 12 weeks, P<0.05). In contrast, amlodipine had no affect on urinary protein and TGF-beta1 excretion. Both losartan and amlodipine failed to reduce serum TGF-beta1 levels.. Losartan and amlodipine, with similar control of BP, showed different effects on urine protein or TGF-beta1 excretion. Whereas losartan improved both urinary parameters, amlodipine did not. These differences might be important for the management of IgA nephropathy.

Topics: Adult; Amlodipine; Antihypertensive Agents; Blood Pressure; Female; Glomerulonephritis, IGA; Humans; Hypertension; Losartan; Male; Middle Aged; Proteinuria; Transforming Growth Factor beta; Transforming Growth Factor beta1; Treatment Outcome

Proteinuria is a significant independent determinant of the progression of chronic renal diseases. It induces an increased synthesis of angiotensin II, endothelin and profibrogenic growth factors, such as transforming growth factor-beta (TGF-beta), by mesangial and tubular cells. The antiproteinuric effect of angiotensin-converting enzyme inhibitors (ACEIs) in diabetic and non-diabetic nephropathies predicts long-term renoprotection afforded by these drugs. Angiotensin II receptor antagonists are renoprotective in patients with type 2 diabetes, but studies about their effect in non-diabetic proteinuric nephropathies are very scarce.. We randomly assigned 97 patients with non-diabetic nephropathies and proteinuria >1.5 g/24 h to treatment with losartan (50 mg daily) or amlodipine (5 mg daily) for 20 weeks. Doses of the study medications were titrated to achieve a target blood pressure <140/90 mmHg in both groups. Primary outcome was the decrease in the level of 24 h proteinuria. Secondary outcomes were changes in the plasma and urinary levels of TGF-beta.. The baseline characteristics in both groups were similar. Proteinuria decreased by 32.4% (95% confidence interval -38.4 to -21.8%) after 4 weeks of treatment and by 50.4% (-58.9 to -40.2%) after 20 weeks in the losartan group, whereas no significant proteinuria changes were observed in the amlodipine group (P < 0.001). There was no significant correlation between the level of baseline proteinuria and the proteinuria decrease induced by losartan. Both losartan and amlodipine induced a similar and significant blood pressure reduction. Target blood pressure was achieved with the initial dose of study medication (50 mg daily) in 76% of losartan group patients and in 68% of the amlodipine group patients (5 mg daily). Urinary TGF-beta significantly decreased with losartan (-22.4% of the baseline values after 20 weeks of treatment), whereas it tended to increase with amlodipine (between-group difference P < 0.05). A significant correlation between proteinuria decrease and urinary TGF-beta reduction was found in the losartan group (r = 0.41, P < 0.005). Serum creatinine and serum potassium remained stable during the study in both groups.. Losartan induced a drastic decrease in proteinuria accompanied by a reduction in urinary excretion of TGF-beta in patients with non-diabetic proteinuric renal diseases.

Topics: Adult; Amlodipine; Angiotensin Receptor Antagonists; Antihypertensive Agents; Calcium Channel Blockers; Diabetes Mellitus; Double-Blind Method; Female; Humans; Kidney Diseases; Losartan; Male; Middle Aged; Prospective Studies; Proteinuria; Transforming Growth Factor beta; Treatment Outcome

The therapeutic benefits of dual blockade of the renin-angiotensin system (RAS) have been inconsistent on renal function and proteinuria. To know the contribution of the heterogeneity of study subjects to such inconsistency, we evaluated the effects of dual blockade of RAS in 2 groups of selected renal diseases, IgA and diabetic nephropathy. To avoid confounding by the blood pressure-reducing effects, angiotensin II receptor antagonists (ATRAs) were added on the patients with long-term, optimally controlled blood pressure taking ACE inhibitors. Twenty-four-hour urinary protein excretion rate and urinary TGF-beta1 level were measured as surrogate markers of renal injury.. We conducted a prospective crossover trial with 14 IgA and 18 type-2-diabetic nephropathy patients showing moderate degree of proteinuria (> or = 1.0 g/day) and renal dysfunction (creatinine clearance 25 - 75/ml/min). Four to 8 mg once-daily dose of candesartan and placebo were alternatively added on ramipril dose of 5 - 7.5 mg/day for 16 weeks.. All baseline data except for the age factor were statistically the same between the 2 disease groups. Twenty-four-hour mean arterial blood pressures were 91.2 +/- 1.6 and 92.3 +/- 1.8 mmHg in IgA and diabetic nephropathy patients respectively at baseline (p = NS). Mean arterial pressure did not change by the addition of candesartan or placebo in both groups. The addition of candesartan (combination) reduced 24-hour urinary protein excretion rate in IgA nephropathy patients with a mean change of -12.3 +/- 4.5%, which is significantly greater compared to a mean change of -0.1 +/- 3.3% after the addition of placebo (placebo) (mean difference 12.4 +/- 5.0, 95% CI 1.2 - 23.5; p < 0.05). Urinary TGF-beta1 level was reduced considerably by the combination therapy, with a -28.9 +/- 6.0% decrease, which was significantly different to that by the placebo, with +4.3 +/- 12.4% (33.3 +/- 13.5, 3.2 - 63.3; p < 0.05). In diabetic nephropathy patients, the addition of candesartan did not reduce 24-hour urinary protein excretion rate. Mean changes of 24-hour urinary protein excretion rate were -0.8 +/- 4.7% by the combination therapy and +0.5 +/- 6.1% by placebo (mean difference 1.3 +/- 4.7, 95% CI -6.8 - 13.5; p < NS). The level of urinary TGF-beta1 was reduced by the combination therapy, with -14.3 +/- 9.5% decrease, but it did not reach statistical significance compared to placebo of +0.7 +/- 15.5% (15.0 +/- 13.5, -14.4 - 44.5; p < NS). The changes in 24-hour urinary protein excretion rate and urinary TGF-beta1 level were neither correlated with each other, nor with the change in mean arterial pressure. Significant changes in the renal function were not detected during the study period.. Definite beneficial effects of dual blockade of RAS on proteinuria and TGF-beta1 excretion were found in IgA nephropathy patients, which was independent of blood pressure-reducing effect. With our 16-week trial, such benefits were not observed in type 2 diabetic nephropathy. The reduction in urinary TGF-beta1 level suggests that the combination therapy may provide additional renoprotection through the antisclerosing effects. Based on our results, for a proper interpretation the therapeutic effects of the combination therapy should be evaluated separately according to the underlying renal disease.

Topics: Adult; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Benzimidazoles; Biphenyl Compounds; Cross-Over Studies; Diabetic Nephropathies; Female; Glomerulonephritis, IGA; Humans; Male; Middle Aged; Prospective Studies; Proteinuria; Ramipril; Renin-Angiotensin System; Tetrazoles; Transforming Growth Factor beta

Progression of renal failure, despite renoprotection with angiotensin-converting enzyme (ACE) inhibitors in patients with proteinuric nephropathies, may be caused by persistent renal production of transforming growth factor-beta1 (TGF-beta1) through the angiotensin II subtype 1 (AT1) receptors. We tested the hypothesis that AT1-receptor blocker therapy added to a background of chronic maximal ACE inhibitor therapy will result in a reduction in urinary TGF-beta1 levels in such patients. Sixteen patients completed a two-period, crossover, randomized, controlled trial, details of which have been previously reported. All patients were administered lisinopril, 40 mg/d, with either losartan, 50 mg/d, or placebo. Blood pressure (BP) was measured using a 24-hour ambulatory BP monitor. Overnight specimens of urine were analyzed for urine TGF-beta1, protein, and creatinine concentrations. Mean age of the study population was 53 +/- 9 (SD) years; body mass index, 38 +/- 5.7 kg/m2; seated BP, 156 +/- 18/88 +/- 12 mm Hg; and urine protein excretion, 3.6 +/- 0.71 g/g of creatinine. Twelve patients had diabetic nephropathy, and the remainder had chronic glomerulonephritis. At baseline, urinary TGF-beta1 levels were significantly increased in the study population compared with healthy controls (13.2 +/- 1.2 versus 1.7 +/- 1.1 ng/g creatinine; P < 0.001). There was a strong correlation between baseline urine protein excretion and urinary TGF-beta1 level (r2 = 0.53; P = 0.001), as well as systolic BP and urinary TGF-beta1 level (r2 = 0.57; P < 0.001). After 4 weeks of add-on losartan therapy, there was a 38% (95% confidence interval [CI], 16% to 55%) decline in urinary TGF-beta1 levels (13.3 [95% CI, 11.4 to 15.5] to 8.2 pg/mg creatinine [95% CI, 6.2 to 10.7]). The reduction in urinary TGF-beta1 levels occurred independent of changes in mean urinary protein excretion or BP. Thus, proteinuric patients with renal failure, despite maximal ACE inhibition, had increased urinary levels of TGF-beta1 that improved over 1 month of add-on therapy with losartan. We speculate that dual blockade with losartan and an ACE inhibitor may provide additional renoprotection by decreasing renal production of TGF-beta1.

Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Blood Pressure; Cross-Over Studies; Drug Therapy, Combination; Female; Humans; Hypertension; Kidney Failure, Chronic; Lisinopril; Losartan; Male; Middle Aged; Proteinuria; Transforming Growth Factor beta

Chronic allograft nephropathy represents the principal cause of graft loss after the first year of transplantation. Transforming growth factor-beta1 (TGF-beta1) is a key factor in fibrogenesis and has been involved in the pathogenesis of chronic allograft nephropathy and other chronic nephropathies. Experimental studies have demonstrated that the angiotensin II receptor antagonist (losartan) could decrease the synthesis of TGF-beta1. The aim of this study was to determine the plasma levels of TGF-beta1 in transplant patients with chronic allograft nephropathy, and to evaluate the effect of losartan on TGF-beta1 plasma levels and other vasoactive peptides (angiotensin II, plasma renin activity, aldosterone, endothelin-1, and nitrites and nitrates). Angiotensin-converting enzyme genotypes were also determined in all patients.. Fourteen transplant patients with chronic allograft nephropathy were included. Treatment with losartan (50 mg) was introduced. Consecutive determinations of TGF-beta1 and other vasoactive peptides were performed during follow-up.. Patients with chronic allograft nephropathy presented higher plasma levels of TGF-beta1 than the control groups. The treatment with losartan significantly decreased the plasma levels of TGF-beta1 (P < 0.05) and endothelin (P < 0.05) in all patients. The decrease of TGF-beta1 was statistically correlated with the blockade of the angiotensin II receptor (P < 0.05). No significant correlation could be demonstrated between angiotensin-converting enzyme genotypes and TGF-beta, endothelin-1, and nitrite-nitrate serum levels.. This study demonstrates that losartan significantly decreases the plasma levels of TGF-beta1, the most important fibrogenetic factor. These results could play a decisive role in the treatment and prevention of chronic nephropathies, not only graft nephropathy, because the intrinsic pathogenetic mechanism is very similar in all forms, with a crucial roles for the renal renin-angiotensin system and TGF-beta1.

Topics: Adult; Aged; Angiotensin II; Antihypertensive Agents; Blood Pressure; Chronic Disease; Endothelins; Female; Fibrosis; Follow-Up Studies; Graft Rejection; Humans; Kidney; Kidney Failure, Chronic; Kidney Transplantation; Losartan; Male; Middle Aged; Pilot Projects; Proteinuria; Transforming Growth Factor beta; Transplantation, Homologous; Vasoconstrictor Agents

CD22, mainly expressed in mature B cells, could negatively regulate the function of B cells by binding to sialic acid-positive IgG (SA-IgG). Soluble CD22 (sCD22) is generated by the cleavage of the extracellular domain of CD22 on the membrane surface. However, the role of CD22 in IgA nephropathy (IgAN) remains unknown.. A total of 170 IgAN patients with a mean follow-up of 18 months were included in this study. The sCD22, TGF-β, IL-6 and TNF-α were detected using commercial ELISA kits. SA-IgG were purified to stimulate peripheral blood mononuclear cells (PBMCs) from IgAN patients.. The plasma levels of sCD22 were lower in IgAN patients in comparison with healthy control. Furthermore, CD22 mRNA levels in PBMCs from patients with IgAN were significantly lower than those of healthy controls. The plasma levels of sCD22 were positively correlated to the mRNA levels of CD22. We found that patients with higher sCD22 levels had a lower level of serum creatinine and a higher level of eGFR on the time of renal biopsy and a higher remission rate of proteinuria and a lower risk of kidney events at the end of follow-up. The logistic regression analysis showed sCD22 was associated with an increased odd of proteinuria remission after being adjusted for eGFR, proteinuria, and SBP. After adjusting for confounding variables, sCD22 was a borderline significant predictor of less kidney composite endpoint. In addition, the sCD22 levels were positively associated with SA-IgG in plasma. The experimental results in vitro showed that addition of SA-IgG enhanced the release of sCD22 in cell supernatant and the phosphorylation of CD22 in PBMCs, further inhibiting the production of IL-6, TNF-α, and TGF-β in cell supernatant in a dose-dependent manner. Pretreatment with CD22-antibody significantly increased the expression of cytokines in PBMCs.. This is the first study to demonstrate that lower plasma soluble CD22 in IgAN patients and high soluble CD22 levels are associated with an increased odd of proteinuria remission and a decreased odd of kidney endpoint. The interaction between CD22 and SA-IgG can inhibit proliferation and inflammation release in PBMCs from IgAN patients.

Topics: Cytokines; Glomerulonephritis, IGA; Humans; Immunoglobulin G; Interleukin-6; Leukocytes, Mononuclear; Prognosis; Proteinuria; RNA, Messenger; Sialic Acid Binding Ig-like Lectin 2; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Alport syndrome (ALP) is a rare genetic condition characterized by progressive involvement of the basal membranes and renal dysfunction. The purpose of the study was to evaluate urinary (u) and serum (s) levels of tumor growth factor (TGF)-beta(β) and high mobility group box (HMGB)-1 in ALP patients with normal renal function, albuminuria and proteinuria.. A prospective, single-center study was performed with a follow-up period of 12 months, enrolling 11 pediatric ALP patients and 10 healthy subjects (HS). Normal values of serum creatinine, albuminuria and proteinuria, as well as unaltered estimated glomerular filtration rate (eGFR) were required at enrollment.. ALP patients had significantly higher levels of serum and urinary HMGB1 compared to HS. The same trend was observed for TGF-β1, with higher values in ALP patients than in HS. HMGB1 and TGF-β1 correlated with each other and with markers of renal function and damage. Urinary biomarkers did not correlate with eGFR, whereas sHMGB1 and sTGF-β1 were negatively related to filtration rate (r: - 0.66; p = 0.02, r: - 0.96; p < 0.0001, respectively). Using proteinuria as a dependent variable in a multiple regression model, only the association with sTGF-β1 (β = 0.91, p < 0.0001) remained significant.. High levels of HMGB1 and TGF-β1 characterized ALP patients with normal renal function, highlighting the subclinical pro-fibrotic and inflammatory mechanisms triggered before the onset of proteinuria. Further studies are needed to evaluate the role of HMGB1 and TGFβ-1 in ALP patients.

Topics: Child; HMGB1 Protein; Humans; Nephritis, Hereditary; Prospective Studies; Proteinuria; Transforming Growth Factor beta; Transforming Growth Factor beta1

Glomerulonephritis (GN) is a common cause of end-stage kidney disease and is characterized by glomerular inflammation, hematuria, proteinuria, and progressive renal dysfunction. Transforming growth factor (TGF)-β is involved in glomerulosclerosis and interstitial fibrosis. TGF-β activates multiple signaling pathways, including the canonical SMAD pathway. We evaluated the role of SMAD signaling in renal injury and proteinuria in a murine model of GN. SMAD3

Topics: Animals; Anti-Glomerular Basement Membrane Disease; Autoantibodies; Cell Line; Disease Models, Animal; Endothelial Cells; Fibrosis; Kidney Glomerulus; Membrane Proteins; Mice, Inbred C57BL; Mice, Knockout; Microfilament Proteins; Paracrine Communication; Podocytes; Proteinuria; Signal Transduction; Smad3 Protein; Transforming Growth Factor beta

Transforming growth factor-β (TGF-β) plays crucial roles in the development of focal segmental glomerulosclerosis, but key molecular pathways remain unknown. Here, we identified the regulation of mammalian target of rapamycin complex1 (mTORC1) by TGF-β via ERK1/2 in the Adriamycin-induced murine model of focal segmental glomerulosclerosis. Adriamycin administration elicited early activation of TGF-β-ERK1/2-mTORC1 in podocytes, which persisted at later stages of albuminuria and glomerulosclerosis. Phosphorylation of the TGF-β receptor-I (TGF-βRI), Smad3, ERK1/2 and ribosomal protein S6 were evident in the glomeruli of adriamycin-treated mice. Targeting TGFβ-RI and mTORC1 with pharmacological inhibitors suppressed TGF-β signaling in glomeruli and significantly reduced albuminuria, glomerulosclerosis, protein levels of collagen 4α3, plasminogen activator inhibitor-1, and vimentin and restored mRNA levels of podocyte markers. Low dose US Food and Drug Administration (FDA)-approved MEK/ERK inhibitor trametinib/GSK1120212 blunted TGF-β1-induced mTORC1 activation in podocytes, ameliorated up-regulation of TGF-β, plasminogen activator inhibitor-1, monocyte chemoattractant protein-1, fibronectin and α-smooth muscle actin and prevented albuminuria and glomerulosclerosis with improved serum albumin. In cultured podocytes, this pathway was found to be associated with translation of fibrogenic collagen 4α3 and plasminogen activator inhibitor-1, without influencing their transcription. Notably, rapamycin suppressed upstream p-TGF-βRI, p-Smad3 and p-ERK1/2, and trametinib down-regulated upstream p-Smad3 in ex vivo and in vivo studies, indicating that harmful paracrine signaling among glomerular cells amplified the TGF-β-ERK1/2-mTORC1 axis by forming a positive feedback loop. Thus, an accentuated TGF-β-ERK1/2-mTORC1 pathway is suggested as a central upstream mediator to develop proteinuria and glomerulosclerosis. Hence, preventing activation of this vicious loop by trametinib may offer a new therapeutic strategy for glomerular disease treatment.

Topics: Animals; Cell Line; Disease Models, Animal; Doxorubicin; Drug Evaluation, Preclinical; Glomerulosclerosis, Focal Segmental; Humans; Kidney Glomerulus; Male; MAP Kinase Signaling System; Mechanistic Target of Rapamycin Complex 1; Mice; Phosphorylation; Proteinuria; Pyridones; Pyrimidinones; Rats; Transforming Growth Factor beta

Different complex mechanisms control the morphology of podocyte foot processes and their interactions with the underlying basement membrane. Injuries to this system often cause glomerular dysfunction and albuminuria. The present study aimed at identifying early markers of glomerular damage in diabetic nephropathy. For this purpose, we performed a microarray analysis on kidneys of 3-wk-old peroxisome proliferator-activated receptor-γ (PPARγ)-null and AZIP/F1 mice, which are two models of diabetic nephropathy due to lipodystrophy. This was followed by functional annotation of the enriched clusters of genes. One of the significant changes in the early stages of glomerular damage was the increase of hemicentin 1 (HMCN1). Its expression and distribution were then studied by real-time PCR and immunofluorescence in various models of glomerular damage and on podocyte cell cultures. HMCN1 progressively increased in the glomeruli of diabetic mice, according to disease severity, as well as in puromycin aminonucleoside (PA)-treated rats. Studies on murine and human podocytes showed an increased HMCN1 deposition upon different pathological stimuli, such as hyperglycemia, transforming growth factor-β (TGF-β), and PA. In vitro silencing studies showed that HMCN1 mediated the rearrangements of podocyte cytoskeleton induced by TGF-β. Finally, we demonstrated an increased expression of HMCN1 in the kidneys of patients with proteinuric nephropathies. In summary, our studies identified HMCN1 as a new molecule involved in the dynamic changes of podocyte foot processes. Its increased expression associated with podocyte dysfunction points to HMCN1 as a possible marker for the early glomerular damage occurring in different proteinuric nephropathies.

Topics: Animals; Calcium-Binding Proteins; Cells, Cultured; Cytoskeleton; Diabetic Nephropathies; Disease Models, Animal; Extracellular Matrix Proteins; Female; Glucose; Humans; Immunoglobulins; Male; Mice, Inbred C57BL; Mice, Knockout; Nephrosis; Podocytes; PPAR gamma; Proteinuria; Rats, Sprague-Dawley; Signal Transduction; Transforming Growth Factor beta; Up-Regulation

Mitochondrial intracrines are extracellular signaling proteins, targeted to the mitochondria. The pathway for mitochondrial targeting of mitochondrial intracrines and actions in the mitochondria remains unknown. Megalin/LRP2 mediates the uptake of vitamins and proteins, and is critical for clearance of amyloid-β protein from the brain. Megalin mutations underlie the pathogenesis of Donnai-Barrow and Lowe syndromes, characterized by brain defects and kidney dysfunction; megalin was not previously known to reside in the mitochondria. Here, we show megalin is present in the mitochondria and associates with mitochondrial anti-oxidant proteins SIRT3 and stanniocalcin-1 (STC1). Megalin shuttles extracellularly-applied STC1, angiotensin II and TGF-β to the mitochondria through the retrograde early endosome-to-Golgi transport pathway and Rab32. Megalin knockout in cultured cells impairs glycolytic and respiratory capacities. Thus, megalin is critical for mitochondrial biology; mitochondrial intracrine signaling is a continuum of the retrograde early endosome-to-Golgi-Rab32 pathway and defects in this pathway may underlie disease processes in many systems.

Topics: Agenesis of Corpus Callosum; Amyloid beta-Peptides; Animals; Brain; Cell Membrane; Glycoproteins; Hearing Loss, Sensorineural; HEK293 Cells; Hernias, Diaphragmatic, Congenital; Humans; Low Density Lipoprotein Receptor-Related Protein-2; Mice; Mitochondria; Myopia; Oculocerebrorenal Syndrome; Proteinuria; rab GTP-Binding Proteins; RAW 264.7 Cells; Renal Tubular Transport, Inborn Errors; Signal Transduction; Sirtuin 3; Transforming Growth Factor beta

Chronic kidney disease (CKD) and arterial stiffness are associated with increased cardiovascular morbidity and mortality. Inflammation is proposed to have a role in the development of arterial stiffness, and CKD is recognized as a proinflammatory state. Arterial stiffness is increased in CKD, and cross-sectional data has suggested a link between increased inflammatory markers in CKD and higher measures of arterial stiffness. However, no large scale investigations have examined the impact of inflammation on the progression of arterial stiffness in CKD.. We performed baseline assessments of 5 inflammatory markers in 3,939 participants from the chronic renal insufficiency cohort (CRIC), along with serial measurements of arterial stiffness at 0, 2, and 4 years of follow-up.. A total of 2,933 participants completed each of the follow-up stiffness measures. In cross-sectional analysis at enrollment, significant associations with at least 2 measures of stiffness were observed for fibrinogen, interleukin-6, high-sensitivity C-reactive protein, proteinuria, and composite inflammation score after adjustment for confounders. In longitudinal analyses, there were few meaningful correlations between baseline levels of inflammation and changes in metrics of arterial stiffness over time.. In a large cohort of CKD participants, we observed multiple significant correlations between initial markers of inflammation and metrics of arterial stiffness, but baseline inflammation did not predict changes in arterial stiffness over time. While well-described biologic mechanisms provide the basis for our understanding of the cross-sectional results, continued efforts to design longitudinal studies are necessary to fully elucidate the relationship between chronic inflammation and arterial stiffening.

Topics: Adult; Aged; Blood Pressure; C-Reactive Protein; Cohort Studies; Enzyme-Linked Immunosorbent Assay; Female; Fibrinogen; Follow-Up Studies; Humans; Inflammation; Interleukin 1 Receptor Antagonist Protein; Interleukin-1beta; Interleukin-6; Linear Models; Male; Middle Aged; Proteinuria; Pulse Wave Analysis; Renal Insufficiency, Chronic; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Vascular Stiffness

The pathogenesis of hyperuricemia-induced chronic kidney disease is largely unknown. In this study, we investigated whether extracellular signal-regulated kinases1/2 (ERK1/2) would contribute to the development of hyperuricemic nephropathy (HN). In a rat model of HN induced by feeding mixture of adenine and potassium oxonate, increased ERK1/2 phosphorylation and severe glomerular sclerosis and renal interstitial fibrosis were evident, in parallel with diminished levels of renal function and increased urine microalbumin excretion. Administration of U0126, which is a selective inhibitor of the ERK1/2 pathway, improved renal function, decreased urine microalbumin and inhibited activation of renal interstitial fibroblasts as well as accumulation of extracellular proteins. U0126 also inhibited hyperuricemia-induced expression of multiple profibrogenic cytokines/chemokines and infiltration of macrophages in the kidney. Furthermore, U0126 treatment suppressed xanthine oxidase, which mediates uric acid production. It also reduced expression of the urate anion exchanger 1, which promotes reabsorption of uric acid, and preserved expression of organic anion transporters 1 and 3, which accelerate uric acid excretion in the kidney of hyperuricemic rats. Finally, U0126 inhibited phosphorylation of Smad3, a key mediator in transforming growth factor (TGF-β) signaling. In cultured renal interstitial fibroblasts, inhibition of ERK1/2 activation by siRNA suppressed uric acid-induced activation of renal interstitial fibroblasts. Collectively, pharmacologic targeting of ERK1/2 can alleviate HN by suppressing TGF-β signaling, reducing inflammation responses, and inhibiting the molecular processes associated with elevation of blood uric acid levels in the body. Thus, ERK1/2 inhibition may be a potential approach for the prevention and treatment of hyperuricemic nephropathy.

Topics: Animals; Anion Transport Proteins; Cytokines; Disease Models, Animal; Disease Progression; Fibroblasts; Hyperuricemia; Kidney Diseases; Kidney Function Tests; Macrophages; Male; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; NF-kappa B; Organic Anion Transport Protein 1; Organic Anion Transporters, Sodium-Independent; Phosphorylation; Protein Kinase Inhibitors; Proteinuria; Rats; Signal Transduction; Smad Proteins; Transforming Growth Factor beta; Uric Acid

Thymosin β4 (Tβ4) is closely associated with the cytoskeleton, inflammation, wound healing, angiogenesis, apoptosis, and myocardial regeneration, but the effects of Tβ4 treatment on chronic renal tubular interstitial fibrosis (CRTIF) are poorly known. This study aimed to examine the effects of Tβ4 on the renal apoptosis and the expression of transforming growth factor (TGF-β), E-cadherin, and α-smooth muscle actin (α-SMA) in CRTIF rat models.. Male SD rats were randomized into four groups (sham group, unilateral ureteral obstruction (UUO) group, UUO + low-dose Tβ4 group, and UUO + high-dose Tβ4 group). The pathological changes of kidney tissue and its function were assessed two weeks after UUO. In renal interstitial tissue,TGF-β, E-cadherin and α-SMA expression was detected by western blot. In tubular epithelial cells, E-cadherin and α-SMA expression was detected using Real-time qPCR and western blot. Cell apoptosis of rat renal interstitial tissue and tubular epithelial cells was evaluated by immunofluorescence and western blot.. Two weeks after UUO, no differences in blood urea nitrogen and creatinine were observed between the four groups (P > 0.05). Compared to the UUO group, Tβ4 treatment decreased the 24-h proteinuria (P < 0.001) and reduced the area of pathological change (P < 0.01); this effect was more apparent in the UUO + high-dose Tβ4 group. Compared to the UUO group, a significant decrease in TGF-β and α-SMA protein expression was observed in the high-dose Tβ4 group. The level of E-cadherin protein was lower in the UUO group than the Tβ4 groups, and high-dose Tβ4 treatment further increased E-cadherin expression and improved cell apoptosis in the renal interstitial tissue. Analysis of in vitro tubular epithelial cells showed that α-SMA mRNA and protein expression decreased, while E-cadherin mRNA and protein expression increased by Tβ4 treatment. Similarly, these changes were more significant in the UUO + high-dose Tβ4 group. Tβ4 treatment improved the apoptosis of In vitro tubular epithelial cells compared with pure TGF-β stimulation, and equally, the decrease of apoptosis was more apparent in the TGF-β + high-dose Tβ4 group.. Tβ4 treatment might alleviate the renal fibrosis and apoptosis of tubular epithelial cells through TGF-β pathway inhibition in UUO rats with CRTIF.

Topics: Actins; Animals; Apoptosis; Cadherins; Cells, Cultured; Disease Models, Animal; Epithelial Cells; Fibrosis; Kidney; Kidney Tubules; Male; Proteinuria; Rats; Rats, Sprague-Dawley; RNA, Messenger; Signal Transduction; Thymosin; Transforming Growth Factor beta; Ureteral Obstruction

Blockade of the renin-angiotensin II (Ang II) system by AT1 blockers (ARBs) and angiotensin-converting enzyme inhibitors retards the progression of chronic kidney disease (CKD) by reducing albuminuria/proteinuria. However, many patients with CKD suffer from residual albuminuria/proteinuria, which is an independent risk factor for CKD progression. The aim of the current study is to investigate the effect of pitavastatin, one of the adjunctive agents to ARBs, on the reduction of albuminuria/proteinuria and further renoprotection mediated by telmisartan in spontaneously hypertensive rats.. Forty-two-week-old spontaneously hypertensive rats were grouped randomly and received 8 weeks of treatments with vehicle, telmisartan, pitavastatin or a combination of telmisartan and pitavastatin. Both albuminuria and proteinuria were inhibited significantly in the telmisartan-treated group, but an obviously residual albuminuria was maintained. The combination treatment with telmisartan and pitavastatin displayed a more effective decrease in albuminuria and proteinuria, even to the normal level. Enhanced nephroprotection was also observed in this combination group, which was independent of the cholesterol-lowering effects. Further mechanistic studies revealed that the combination therapy greatly attenuated the expression of intrarenal Ang II and AT1, thereby decreasing the activation of TGF-β-Smad and NF-κB and inhibiting fibrosis and inflammation.. Adjunctive therapy with pitavastatin dramatically reduced residual albuminuria/proteinuria and enhanced nephroprotection, likely by downregulating the expression of intrarenal Ang II and AT1. It could be concluded that statins might be a promising adjunctive therapeutic agent to conventional ARB treatment in hypertensive renal damage.

Topics: Albuminuria; Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Animals; Benzimidazoles; Benzoates; Down-Regulation; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertension, Renal; Kidney; Male; Nephritis; NF-kappa B; Proteinuria; Rats; Rats, Inbred SHR; Receptor, Angiotensin, Type 1; Renin-Angiotensin System; Signal Transduction; Telmisartan; Transforming Growth Factor beta

Progressive fibrosis in chronic kidney disease (CKD) is the well-recognized cause leading to the progressive loss of renal function. Emerging evidence indicated a pathogenic role of the NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome in mediating kidney injury. However, the role of NLRP3 in the remnant kidney disease model is still undefined. The present study was undertaken to evaluate the function of NLRP3 in modulating renal fibrosis in a CKD model of 5/6 nephrectomy (5/6 Nx) and the potential involvement of mitochondrial dysfunction in the pathogenesis. Employing NLRP3(+/+) and NLRP3(-/-) mice with or without 5/6 Nx, we examined renal fibrotic response and mitochondrial function. Strikingly, tubulointerstitial fibrosis was remarkably attenuated in NLRP3(-/-) mice as evidenced by the blockade of extracellular matrix deposition. Meanwhile, renal tubular cells in NLRP3(-/-) mice maintained better mitochondrial morphology and higher mitochondrial DNA copy number, indicating an amelioration of mitochondrial abnormality. Moreover, NLRP3 deletion also blunted the severity of proteinuria and CKD-related hypertension. To further evaluate the direct role of NLRP3 in triggering fibrogenesis, mouse proximal tubular cells (PTCs) were subjected to transforming growth factor β1 (TGF-β1), and the cellular phenotypic changes were detected. As expected, TGF-β1-induced alterations of PTC phenotype were abolished by NLRP3 small interfering RNA, in line with a protection of mitochondrial function. Taken together, NLRP3 deletion protected against renal fibrosis in the 5/6 Nx disease model, possibly via inhibiting mitochondrial dysfunction.

Topics: Animals; Cells, Cultured; Hypertension; Mice; Mice, Inbred C57BL; Mitochondrial Diseases; Nephrectomy; Nephrosclerosis; NLR Family, Pyrin Domain-Containing 3 Protein; Proteinuria; Renal Insufficiency, Chronic; RNA, Small Interfering; Transforming Growth Factor beta

Podocytes injury is involved in the development of diabetic nephropathy. This study was designed to confirm the reno- and podocyte-protective effects of pitavastatin in diabetic rats and clarify its mechanisms.. Wistar rats were divided into 4 treatment groups: control, streptozotocin (STZ; 55 mg/kg)-induced diabetes, STZ with pitavastatin (10 mg/kg/day), and STZ with tempol (1 mmol/l).. STZ-induced diabetic rats exhibited increases in urinary protein excretion and plasma creatinine, and a decrease in creatinine clearance. Pitavastatin significantly improved these parameters without reducing cholesterol levels, whereas tempol did not. The treatment with STZ-enhanced renal fibrosis, mesangial proliferation, transforming growth factor (TGF)-β, MCP-1 and suppressed Rho in association with decrement of bone morphogenetic protein (BMP)-7 expression in renal cortex. Moreover, STZ decreased podocyte related factors, podocin and nephrin, and BMP-7 in podocytes. Pitavastatin significantly ameliorated all these indices. On the other hand, improvement by tempol was found only in TGF-β, MCP-1 and histological changes.. Pitavastatin exhibited reno- and podocyte-protective effects accompanied by BMP-7 preservation and Rho suppression.

Topics: Animals; Bone Morphogenetic Protein 7; Chemokine CCL2; Creatinine; Diabetes Mellitus, Experimental; Gene Expression; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Intracellular Signaling Peptides and Proteins; Kidney; Male; Malondialdehyde; Membrane Proteins; Nitrates; Nitrites; Protective Agents; Proteinuria; Quinolines; Rats, Wistar; rho-Associated Kinases; Transforming Growth Factor beta; Up-Regulation

X-linked hereditary nephropathy (XLHN) in Navasota dogs is a spontaneously occurring disease caused by a mutation resulting in defective production of type IV collagen and juvenile-onset renal failure. The study was aimed at examining the evolution of renal damage and the expression of selected molecules potentially involved in the pathogenesis of XLHN. Clinical data and renal samples were obtained in 10 XLHN male dogs and 5 controls at 4 (T0), 6 (T1), and 9 (T2) months of age. Glomerular and tubulointerstitial lesions were scored by light microscopy, and the expression of 21 molecules was investigated by quantitative real-time polymerase chain reaction with selected proteins evaluated by immunohistochemistry. No significant histologic lesions or clinicopathologic abnormalities were identified in controls at any time-point. XLHN dogs had progressive proteinuria starting at T0. At T1, XLHN dogs had a mesangioproliferative glomerulopathy with glomerular loss, tubular necrosis, and interstitial fibrosis. At T2, glomerular and tubulointerstitial lesions were more severe, particularly glomerular loss, interstitial fibrosis, and inflammation. At T0, transforming growth factor β, connective tissue growth factor, and platelet-derived growth factor α mRNA were overexpressed in XLHN dogs compared with controls. Clusterin and TIMP1 transcripts were upregulated in later stages of the disease. Transforming growth factor β, connective tissue growth factor, and platelet-derived growth factor α should be considered as key players in the initial events of XHLN. Clusterin and TIMP1 appear to be more associated with the progression rather than initiation of tubulointerstitial damage in chronic renal disease.

Topics: Animals; Collagen Type IV; Disease Progression; Dog Diseases; Dogs; Genetic Diseases, X-Linked; Immunohistochemistry; Kidney; Kidney Diseases; Kidney Glomerulus; Male; Nephritis, Hereditary; Platelet-Derived Growth Factor; Proteinuria; Real-Time Polymerase Chain Reaction; Transforming Growth Factor beta

Fibrosis is a final common pathway leading to loss of kidney function, in which the fibrogenic cytokine, transforming growth factor β (TGF-β), plays a central role. While previous studies showed that TGF-β antagonism by various means prevents fibrosis in mouse models, clinical approaches based on these findings remain elusive. 1D11 is a neutralizing antibody to all three isoforms of TGF-β. In both adriamycin (ADR)-induced nephropathy and NEP25 podocyte ablation nephropathy, thrice-weekly intraperitoneal administration of 1D11 from the day of disease induction until the mice were sacrificed (day 14 for ADR and day 28 for NEP25), significantly reduced glomerular COL1A2 mRNA accumulation and histological changes. Consistent with our previous findings, proteinuria remained overt in the mice treated with 1D11, suggesting distinct mechanisms for proteinuria and fibrogenesis. Podocyte numbers determined by WT1 staining were significantly reduced in NEP25-model glomeruli as expected, while WT1-positive cells were preserved in mice receiving 1D11. Even when 1D11 was administered after the onset of proteinuria on day 3, 1D11 preserved WT1-positive cell numbers in glomeruli and significantly reduced glomerular scar score (2.5 ± 0.2 [control IgG] vs. 1.8 ± 0.2 [1D11], P < 0.05) and glomerular COL1A2 mRNA expression (19.3 ± 4.4 [control IgG] vs. 8.4 ± 2.4 [1D11] fold increase over the healthy control, P < 0.05). Transmission electron microscopy revealed loss of podocytes and denuded glomerular basement membrane in NEP25 mice with disease, whereas podocytes remained attached to the basement membrane, though effaced and swollen, in those receiving 1D11 from day 3. Together, these data suggest that TGF-β neutralization by 1D11 prevents glomerular fibrosis even when started after the onset of proteinuria. While overt proteinuria and podocyte effacement persist, 1D11 prevents total podocytes detachment, which might be a key event activating fibrogenic events in glomeruli.

Topics: Animals; Antibodies, Monoclonal; Biomarkers; Disease Models, Animal; Doxorubicin; Fibrosis; Kidney Diseases; Kidney Glomerulus; Male; Mice; Podocytes; Proteinuria; Signal Transduction; Transforming Growth Factor beta

TGF-β is known as an important stress factor of podocytes in glomerular diseases. Apart from activation of direct pro-apoptotic pathways we wanted to analyze micro-RNA (miRs) driven regulation of components involved in the integrity of the glomerular filtration barrier induced by TGF-β. Since miR-143-3p (miR-143) is described as a TGF-β inducible miR in other cell types, we examined this specific miR and its ability to induce glomerular pathology.. We analyzed miR-143 expression in cultured human podocytes after stimulation with TGF-β. We also microinjected zebrafish eggs with a miR-143 mimic or with morpholinos specific for its targets syndecan and versican and compared phenotype and proteinuria development.. We detected a time dependent, TGF-β inducible expression of miR-143 in human podocytes. Targets of miR-143 relevant in glomerular biology are syndecans and versican, which are known components of the glycocalyx. We found that syndecan 1 and 4 were predominantly expressed in podocytes while syndecan 3 was largely expressed in glomerular endothelial cells. Versican could be detected in both cell types. After injection of a miR-143 mimic in zebrafish larvae, syndecan 3, 4 and versican were significantly downregulated. Moreover, miR-143 overexpression or versican knockdown by morpholino caused loss of plasma proteins, edema, podocyte effacement and endothelial damage. In contrast, knockdown of syndecan 3 and syndecan 4 had no effects on glomerular filtration barrier.. Expression of versican and syndecan isoforms is indispensable for proper barrier function. Podocyte-derived miR-143 is a mediator for paracrine and autocrine cross talk between podocytes and glomerular endothelial cells and can alter expression of glomerular glycocalyx proteins.

Topics: Animals; Base Sequence; Blood Proteins; Cells, Cultured; Edema; Endothelial Cells; Gene Knockdown Techniques; Glomerular Filtration Barrier; Glycocalyx; Humans; Kidney Glomerulus; Larva; MicroRNAs; Morpholinos; Podocytes; Proteinuria; Proteoglycans; Syndecans; Transforming Growth Factor beta; Up-Regulation; Versicans; Zebrafish; Zebrafish Proteins

Hyperlipidemia is thought to be a major risk factor for the progression of renal diseases in diabetes. Recent studies have shown that lipid profiles are commonly abnormal early on type 2 diabetes mellitus (T2DM) with diabetic nephropathy. However, the early effects of triglyceride and cholesterol abnormalities on renal injury in type 1 diabetes mellitus (T1DM) are not fully understood and require reliable animal models for exploration of the underlying mechanisms. Hamster models are important tools for studying lipid metabolism because of their similarity to humans in terms of lipid utilization and high susceptibility to dietary cholesterol and fat.. Twenty-four male Golden Syrian hamsters (100-110 g) were rendered diabetes by intraperitoneal injections of streptozotocin (STZ) on consecutive 3 days at dose of 30 mg/kg, Ten days after STZ injections, hamsters with a plasma Glu concentration more than 12 mmol/L were selected as insulin deficient ones and divided into four groups (D-C, D-HF, D-HC, and D-HFHC), and fed with commercially available standard rodent chow, high-fat diet, high-cholesterol diet, high-fat and cholesterol diet respectively, for a period of four weeks.. After an induction phase, a stable model of renal injury was established with the aspects of early T1DM kidney disease, These aspects were severe hypertriglyceridemia, hypercholesterolemia, proteinuria with mesangial matrix accumulation, upgraded creatinine clearance, significant cholesterol and triglyceride deposition, and increasing glomerular surface area, thickness of basement membrane and mesangial expansion. The mRNA levels of sterol regulatory element binding protein-1c, transforming growth factors-β, plasminogen activator inhibitor-1, tumor necrosis factor-α and interleukin-6 in the D-HFHC group were significantly up-regulated compared with control groups.. This study presents a novel, non-transgenic, non-surgical method for induction of renal injury in hamsters, which is an important complement to existing diabetic models for pathophysiological studies in early acute and chronic kidney disease, especially hyperlipidemia. These data suggest that both severe hypertriglyceridemia and hypercholesterolemia can accelerate renal injury in the early development of T1DM.

Topics: Animals; Blood Glucose; Cholesterol, Dietary; Creatinine; Cricetinae; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Diet, High-Fat; Disease Models, Animal; Hypercholesterolemia; Hypertriglyceridemia; Interleukin-6; Kidney; Male; Mesocricetus; Plasminogen Activator Inhibitor 1; Proteinuria; RNA, Messenger; Sterol Regulatory Element Binding Protein 1; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Up-Regulation

To investigate the therapeutic effects and potential mechanisms of icariside II (ICA II) on reversing diabetic nephropathy in streptozotocin (STZ)-induced type I diabetic rats.. Newborn male Sprague Dawley rats were labeled with thymidine analog 5-ethynyl-2-deoxyuridine (EdU) for tracking endogenous label retaining progenitor cells (LRCs). At age of 8 weeks, 48 rats were randomly divided into three groups: normal control group (n=16), diabetes mellitus group (DM; n=16), and diabetes mellitus plus ICA II therapy group (DM+ICA II, n=16). Eight weeks induced for diabetes with STZ, rats in DM group and DM+ICA II group were treated with vehicle or ICA II (5 mg/kg/day) for another 8 weeks, respectively. Then, blood creatinine, 24-hour urine protein, blood urea nitrogen, and glycosylated hemoglobin were measured, as well as the expression of von Willebrand factor, malondialdehyde, transforming growth factor-β/drosophila mothers against decapentaplegic protein/connective tissue growth factor (TGF-β/Smad/CTGF) signaling, marker of proliferation Ki-67, and EdU+ LRCs in renal tissues.. Increased levels of creatinine, 24-hour urine protein, and blood urea nitrogen and remarkably decreased proportion of normal glomeruli and increased proportions of I, IIa, IIb, and III glomeruli were observed in diabetic rats, while ICA II could reverse these changes. Interestingly, ICA II could significantly downregulate the levels of malondialdehyde and TGF-β/Smad/CTGF signaling and increase the expression of von Willebrand factor, Ki-67, and EdU+ LRCs in the kidney.. ICA II treatment could ameliorate diabetic nephropathy in STZ-induced diabetic rats by increasing endothelial cell contents, downregulating TGF-β/Smad/CTGF signaling pathway and oxidative stress level, and promoting cell proliferation both in kidney cortex and medulla. These beneficial effects appear to be mediated by its antioxidant capacity and recruitment of endogenous EdU+ progenitor cells into the kidney tissue.

Topics: Animals; Biomarkers; Blood Urea Nitrogen; Cell Proliferation; Cell Tracking; Connective Tissue Growth Factor; Creatinine; Cytoprotection; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Endothelial Progenitor Cells; Flavonoids; Glycated Hemoglobin; Kidney; Male; Oxidative Stress; Proteinuria; Rats, Sprague-Dawley; Signal Transduction; Smad Proteins; Time Factors; Transforming Growth Factor beta

In kidney transplantation, the prevalence of hypercholesterolemia as a co-morbidity factor known to affect graft function, is rising due to the increased number of older donors in response to organ shortage as well as to the hyperlipidemic effects of immunosuppressors in recipient. This study aimed to characterize the effects of hypercholesterolemia on renal graft outcome, investigating the role of oxidized low-density lipoprotein (OxLDL).. In vivo, we used a porcine preclinical model of renal auto-transplantation modulated by two experimental diets: a normal (n = 6) or a hyperlipidemic diet (n = 5) maintained during the 3 month follow-up after the surgical procedure. Kidney function and OxLDL levels were monitored as well as fibrosis, LOX-1 and TGF beta signaling pathways. In vitro, we used human artery endothelial cells subjected to OxLDL to investigate the TGF beta profibrotic pathway and the role of the scavenger receptor LOX-1.. Hyperlipidemic diet-induced increase in plasma OxLDL levels at the time of surgery correlated with an increase in proteinuria 3 months after transplantation, associated with an early graft fibrosis combined with an activation of renal TGF beta signaling. These data suggest a direct involvement of OxLDL in the hyperlipidemic diet-induced activation of the pro-fibrotic TGF beta pathway which seems to be activated by LOX-1 signaling. These results were supported by studies with endothelial cells incubated in culture medium containing OxLDL promoting TGF beta expression inhibited by LOX-1 antibody.. These results implicate OxLDL in the hyperlipidemic diet-promoted fibrosis in transplanted kidneys, suggesting LOX-1 as a potential therapeutic target and reinforce the need to control cholesterol levels in kidney transplant recipients.

Topics: Animals; Antibodies, Blocking; Arteries; Cholesterol; Creatinine; Diet, High-Fat; Endothelial Cells; Endothelium; Fibrosis; Humans; Kidney; Kidney Function Tests; Kidney Transplantation; Lipoproteins, LDL; Male; Models, Animal; Proteinuria; Receptors, Oxidized LDL; Signal Transduction; Sus scrofa; Transforming Growth Factor beta; Transplantation, Autologous; Vimentin

Transforming growth factor-β (TGF-β) has been shown to be involved in diabetic nephropathy (DN). The SnoN protein can regulate TGF-β signaling through interaction with Smad proteins. Recent studies have shown that SnoN is mainly degraded by the ubiquitin-proteasome pathway. However, the role of SnoN in the regulation of TGF- β/Smad signaling in DN is still unclear. In this study, diabetic rats were randomly divided into a diabetic control group (DC group) and a proteasome inhibitor (MG132) diabetes therapy group (DT group). Kidney damage parameters and the expression of SnoN, Smurf2, and TGF-β were observed. Simultaneously, we cultured rat glomerular mesangial cells (GMCs) stimulated with high glucose, and SnoN and Arkadia expression were measured. Results demonstrated that 24-hour urine protein, ACR, BUN, and the expression of Smurf2 and TGF- β were significantly increased (P < 0.05), whereas SnoN was significantly decreased in the DC group (P < 0.05). However, these changes diminished after treatment with MG132. SnoN expression in GMCs decreased significantly (P < 0.05), but Arkadia expression gradually increased due to high glucose stimulation (P < 0.05), which could be almost completely reversed by MG132 (P < 0.05). The present results support the hypothesis that MG132 may alleviate kidney damage by inhibiting SnoN degradation and TGF-β activation, suggesting that the ubiquitin-proteasome pathway may become a new therapeutic target for DN.

Topics: Animals; Diabetic Nephropathies; Down-Regulation; Glucose; Kidney Function Tests; Kidney Glomerulus; Leupeptins; Male; Mesangial Cells; Nerve Tissue Proteins; Proteasome Inhibitors; Proteinuria; Proteolysis; Rats, Wistar; Streptozocin; Transcription Factors; Transforming Growth Factor beta

Tulbaghia violacea has been used traditionally for the treatment of several ailments, including hypertension. The herb has been shown to have antihypertensive properties which have been attributed to its angiotensin-converting enzymeinhibitory (ACEI) activity. It could, therefore, prove beneficial in ameliorating renal pathology associated with hypertension. To evaluate the effects of long-term administration of Tulbaghia violacea on renal function and morphology in the Dahl salt-sensitive (DSS) rat model.. Male DSS rats were treated intra-peritoneally (i.p.) as follows: methanolic extract of Tulbaghia violacea: (TVL) (50 mg/kg/b.w.), captopril: (CAP) (25 mg/kg/b.w.), or distilled water, control: (CON) (3 ml/kg/b.w.). Blood pressure (BP) was measured bi-weekly, whilst 24-h urine volumes and electrolyte concentrations were assessed weekly. Animals were sacrificed on day 49 by halothane overdose. Blood was removed for determination of plasma and serum electrolytes. Left kidney tissues were harvested for the determination of nuclear factor-kappaβ (NF-kβ) and transforming growth factor-β (TGF-β) gene expressions.. TVL significantly reduced mean arterial pressure (MAP) and diastolic blood pressure (DBP). TVL showed reduced blood urea nitrogen, serum creatinine, total protein in urine as well as increased serum total protein. TVL decreased thiobarbituric acid reactive substances (TBARS) and increased glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity and nitric oxide significantly. NF-kβ and TGF-β) gene expressions were significantly reduced in TVL and CAP treated rats. Moreover, renal morphology improved significantly in TVL and CAP treated animals.. TVL and CAP demonstrated marked improvement in renal function and morphology.

Topics: Allium; Animals; Antihypertensive Agents; Arterial Pressure; Biomarkers; Blood Urea Nitrogen; Creatinine; Disease Models, Animal; Gene Expression Regulation; Hypertension; Injections, Intraperitoneal; Kidney; Male; Methanol; NF-kappa B; Oxidative Stress; Phytotherapy; Plant Extracts; Plants, Medicinal; Proteinuria; Rats, Inbred Dahl; Rhizome; Solvents; Time Factors; Transforming Growth Factor beta; Urodynamics

The albumin overload model induces proteinuria and tubulointersitial damage, followed by hypertension when rats are exposed to a hypersodic diet. To understand the effect of kinin system stimulation on salt-sensitive hypertension and to explore its potential renoprotective effects, the model was induced in Sprague-Dawley rats that had previously received a high-potassium diet to enhance activity of the kinin pathway, followed with/without administration of icatibant to block the kinin B₂ receptor (B₂R). A disease control group received albumin but not potassium or icatibant, and all groups were exposed to a hypersodic diet to induce salt-sensitive hypertension. Potassium treatment increased the synthesis and excretion of tissue kallikrein (Klk1/rKLK1) accompanied by a significant reduction in blood pressure and renal fibrosis and with downregulation of renal transforming growth factor-β (TGF-β) mRNA and protein compared with rats that did not receive potassium. Participation of the B₂R was evidenced by the fact that all beneficial effects were lost in the presence of the B₂R antagonist. In vitro experiments using the HK-2 proximal tubule cell line showed that treatment of tubular cells with 10 nM bradykinin reduced the epithelial-mesenchymal transdifferentiation and albumin-induced production of TGF-β, and the effects produced by bradykinin were prevented by pretreatment with the B₂R antagonist. These experiments support not only the pathogenic role of the kinin pathway in salt sensitivity but also sustain its role as a renoprotective, antifibrotic paracrine system that modulates renal levels of TGF-β.

Topics: Animals; Bradykinin; Bradykinin B2 Receptor Antagonists; Cell Line; Female; Fibrosis; Humans; Hypertension; Kidney Diseases; Kidney Tubules; Kinins; Metabolic Networks and Pathways; Potassium, Dietary; Proteinuria; Rats; Rats, Sprague-Dawley; Serum Albumin, Bovine; Sodium Chloride, Dietary; Tissue Kallikreins; Transforming Growth Factor beta

Evidence has demonstrated that Ca(2+)/calmodulin-dependent protein kinase type IV (CaMKIV) contributes to altered cytokine production by promoting the production of inflammatory cytokines. This study aimed to explore the protective role and underlying mechanisms of CaMKIV inhibition in experimental nephrotic syndrome.. BALB/c mice received single intravenous injections of adriamycin (10 mg/kg) then were sacrificed at two, four and six weeks. In the second study, treatment with KN-93, a CaMKIV inhibitor, or vehicle administered via intraperitoneal injection was started five days after adriamycin injection. Functional and pathologic parameters, the presence of inflammatory infiltration and the expressions of pro-inflammatory cytokines were assessed.. The CaMKIV protein expression levels were upregulated in the mice with adriamycin nephropathy, which was significantly inhibited by KN-93 (p<0.01). As compared with the vehicle-treated controls, KN-93 treatment resulted in marked suppression of proteinuria and serum creatinine at week 6 (p<0.01), but not at two weeks after induction of the disease. KN-93 inhibited glomerulosclerosis and the development of tubulointerstitial lesions. The renal alpha-smooth muscle actin (α-SMA) expression was also significantly suppressed by KN-93 treatment at week 6 (p<0.01). Moreover, KN-93 inhibited the renal monocyte chemoattractant protein-1 (MCP-1) expression, paralleled by a reduction in the interstitial infiltration of macrophages and T-cells (p<0.01).. Our findings suggest that activation of CaMKIV signaling is involved in the progression of glomerular diseases with a proteinuric state. Our data therefore justify the development of small molecule CaMKIV inhibitors for the treatment of clinical nephrotic syndrome.

Topics: Actins; Animals; Benzylamines; Calcium-Calmodulin-Dependent Protein Kinase Type 4; Chemokine CCL2; Cytokines; Disease Models, Animal; Doxorubicin; Drug Evaluation, Preclinical; Enzyme Induction; Glomerulosclerosis, Focal Segmental; Kidney; Macrophages; Male; Mice; Mice, Inbred BALB C; Nephritis, Interstitial; Nephrotic Syndrome; Protein Kinase Inhibitors; Proteinuria; Sulfonamides; T-Lymphocytes; Transforming Growth Factor beta; Up-Regulation

Lead intoxication is usually insidious and may cause a variety of complications such as kidney damage and hypertension. The role of intrarenal renin-angiotensin system (RAS) in lead-induced nephropathy has not been investigated. Adult male Sprague-Dawley rats were fed with water containing 250ppm of lead acetate (lead group) and deionized water (control group) for 4weeks. Another two groups started to receive intraperitoneal captopril (50mg/kg/d) or losartan (10mg/kg/d) after 2weeks of lead feeding and continued for another 2weeks. Immunoblotting was used to analyze the protein amount of intrarenal RAS components and transforming growth factor-beta (TGF-β). Compared with control group, lead exposure resulted in increased proteinuria after 2-week treatment (4.2±0.9mg/100g vs. 1.8±0.8mg/100g, p<0.05) and 4-week (5.2±1.7mg/100g, p<0.05). Serum creatinine level was increased (0.40±0.2 vs. 0.3 ±.04mg/dL, p<0.05) and calculated glomerular filtration rate (GFR) was decreased (2.68±1.03 vs. 3.37±0.11mL/min, p<0.05). Intrarenal angiotensin converting enzyme (ACE), angiotensin II (ANG II), angiotensin II type 1 receptor (AT1R) and transforming growth factor-beta (TGF-β) were upregulated in lead group. Captopril and losartan administration reduced proteinuria significantly (3.0±0.50mg/100g of captopril and 2.7±0.4mg/100g of losartan group) and lowered systolic blood pressure when compared with lead group. Furthermore, serum creatinine levels and GFR were improved by RAS blockade. Captopril treatment significantly reduced protein abundance of ACE, ANG II, AT1R and TGF-β. Losartan treatment also decreased ANG II and TGF-β. We concluded that lead exposure elicited intrarenal RAS activation with associated proteinuria and impaired renal function. RAS blockade was effective in alleviating lead-associated kidney injury and lowering blood pressure.

Topics: Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Pressure; Captopril; Gene Expression Regulation; Glomerular Filtration Rate; Kidney Diseases; Lead Poisoning; Losartan; Male; Peptidyl-Dipeptidase A; Proteinuria; Rats; Rats, Sprague-Dawley; Receptor, Angiotensin, Type 1; Renin-Angiotensin System; Transforming Growth Factor beta

Iron is the most abundant metal in mammalian cells, and plays a pivotal role in many metabolic processes. Dysregulated iron homeostasis is involved in the cause of a number of pathological processes including renal diseases.. Longitudinal MRI scans of salt-loaded spontaneously hypertensive stroke-prone rats (SHRSP), an animal model that spontaneously develops hypertensive nephropathy, showed a decrease in renal and hepatic T2 SI (a sign of iron accumulation) of, respectively, 42.3 ± 2.5% (P < 0.01) and 60.4 ± 15.1% (P < 0.01) in comparison with SHRSP fed a standard diet. This was accompanied by the development of renal inflammation and oxidative stress (as evaluated by immunohistochemical and proteomic analyses), mitochondrial dysfunction, massive proteinuria and sustained intravascular hemolysis with the subsequent depletion of plasma haptoglobin, which was responsible for the renal uptake of hemoglobin and iron accumulation. In order to investigate the role of iron in these pathological processes, we subcutaneously treated the salt-loaded rats with the iron chelator deferoxamine (200 mg/kg per day). The pharmacological treatment prevented iron tissue accumulation, as indicated by the increase in renal and hepatic T2 SI of, respectively, 120.0 ± 10.1% (P < 0.01) and 73.9 ± 4.4% (P < 0.01) in comparison with salt-loaded rats treated with vehicle alone. Deferoxamine also preserved renal morphology and function, the renal infiltration of ED-1-positive macrophages/monocytes, and the expression of MCP-1 and TGF-β mRNA, reduced the level of reactive oxygen species, and improved the activity of mitochondrial cytochrome c oxidase.. These findings suggest that iron dysmetabolism is involved in the development of hypertensive nephropathy in SHRSP.

Topics: Animals; Blood Pressure; Deferoxamine; Disease Models, Animal; Hemolysis; Homeostasis; Hypertension, Renal; Iron; Kidney; Male; Models, Animal; Nephritis; Oxidative Stress; Proteinuria; Proteomics; Rats; Rats, Inbred SHR; Reactive Oxygen Species; Sodium Chloride, Dietary; Stroke; Transforming Growth Factor beta

Pirfenidone (PFD) is a novel anti-fibrotic agent that targets TGFβ. However, the mechanisms underlying its renoprotective properties in hypertension-induced renal injury are poorly understood. We investigated the renoprotective properties of PFD and clarified its renoprotective mechanisms in a rat hypertension-induced renal injury model. Dahl salt-sensitive rats were fed a high-salt diet with or without 1% PFD for 6 weeks. During the administration period, we examined the effects of PFD on blood pressure and renal function. After the administration, the protein levels of renal TGFβ, Smad2/3, TNFα, MMP9, TIMP1, and catalase were examined. In addition, total serum antioxidant activity was measured. Compared to untreated rats, PFD treatment significantly attenuated blood pressure and proteinuria. Histological study showed that PFD treatment improved renal fibrosis. PFD may exert its anti-fibrotic effects via the downregulation of TGFβ-Smad2/3 signaling, improvement of MMP9/TIMP1 balance, and suppression of fibroblast proliferation. PFD treatment also increased catalase expression and total serum antioxidant activity. In contrast, PFD treatment did not affect the expression of TNFα protein, macrophage or T-cell infiltration, or plasma interleukin 1β levels. PFD prevents renal injury via its anti-fibrotic and anti-oxidative stress mechanisms. Clarifying the renoprotective mechanisms of PFD will help improve treatment for chronic renal diseases.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Blood Pressure; Catalase; Fibrosis; Gene Expression Regulation; Hypertension, Renal; Kidney; Male; Matrix Metalloproteinase 9; Oxidative Stress; Proteinuria; Pyridones; Rats; Rats, Inbred Dahl; Signal Transduction; Smad2 Protein; Smad3 Protein; Sodium Chloride, Dietary; Tissue Inhibitor of Metalloproteinase-1; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Imatinib is a selective tyrosine kinase inhibitor that can block platelet-derived growth factor (PDGF) receptor activity. Imatinib is also known as an anti-inflammatory agent. We examined the therapeutic effects of long- or short-term imatinib treatment in Wistar-Kyoto (WKY) rats with established anti-glomerular basement membrane (GBM) nephritis.. Nephrotoxic serum (NTS) nephritis was induced in WKY rats on day 0. Groups of animals were given either imatinib or vehicle daily by intraperitoneal injection, from day 7 to day 49 in the long-term treatment study, and from day 7 to 13 in the short-term treatment study; all rats were sacrificed at day 50.. In long-term treatment, imatinib showed marked renoprotective effects; imatinib suppressed proteinuria, improved renal function, attenuated the development of glomerulosclerosis and tubulointerstitial injury and reduced the expression levels of collagen type I and transforming growth factor-beta (TGF-β) in renal cortex. The key finding of the present study was that short-term treatment with imatinib also significantly attenuated the development of renal injury until day 50, although the degree of renoprotection was slightly inferior to that of long-term treatment.. These results suggest that administration of imatinib is a promising strategy for limiting the progression of glomerulonephritis (GN) to end-stage renal failure. In particular, a short period of treatment at an early stage of GN is more beneficial in terms of cost-effectiveness and reduction of adverse effects in comparison to a continuous and long period of treatment.

Topics: Animals; Anti-Glomerular Basement Membrane Disease; Benzamides; Collagen Type I; Creatinine; Disease Progression; Female; Fluorescent Antibody Technique; Imatinib Mesylate; Piperazines; Protein Kinase Inhibitors; Proteinuria; Pyrimidines; Rats; Rats, Inbred WKY; Real-Time Polymerase Chain Reaction; Renal Insufficiency, Chronic; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Time Factors; Transforming Growth Factor beta

Recent evidence indicates that bone marrow-derived mesenchymal stem cells (BM-MSCs) possess immunosuppressive properties both in vitro and in vivo. We have previously demonstrated that transplantation of human MSCs can significantly improve the autoimmune conditions in MRL/lpr mice. The current study aimed to determine the mechanisms by which murine BM-MSC transplantation (MSCT) ameliorates nephritis in MRL/lpr mice. In this study, we found that MSCT can significantly prolong the survival of MRL/lpr mice. Eight weeks after transplantation, MSCT-treated mice showed significantly smaller spleens than control animals, with fewer marginal zones (MZs), T1, T2, activated B-cells, and plasma cells. Moreover, serum levels of B-cell activating factor (BAFF) and IL-10 in MSCT-treated mice decreased significantly compared to those in the control group, while levels of serum TGF-β were increased. Notably, decreased BAFF expression in both spleen and kidney was accompanied by decreased production of anti-dsDNA autoantibodies and proteinuria in MSCT-treated mice. Since BAFF is mainly expressed by T-cells and dendritic cells, we incubated BM-MSCs and DCs together and found that the production of BAFF by DCs was suppressed by MSCs. Thus, our findings suggest that MSCT may suppress the excessive activation of B-cells via inhibition of BAFF production in MRL/lpr mice.

Topics: Animals; Autoantibodies; B-Cell Activating Factor; B-Lymphocytes; Bone Marrow Cells; Cells, Cultured; Female; Interleukin-10; Kidney; Lymphocyte Activation; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Mice, Inbred BALB C; Mice, Inbred MRL lpr; Nephritis; Proteinuria; Spleen; T-Lymphocytes; Transforming Growth Factor beta; Transplantation, Homologous

Smad7 is an inhibitory Smad and plays a protective role in obstructive and diabetic kidney disease. However, the role and mechanisms of Smad7 in hypertensive nephropathy remains unexplored. Thus, the aim of this study was to investigate the role and regulatory mechanisms of Smad7 in ANG II-induced hypertensive nephropathy. Smad7 gene knockout (KO) and wild-type (WT) mice received a subcutaneous infusion of ANG II or control saline for 4 weeks via osmotic mini-pumps. ANG II infusion produced equivalent hypertension in Smad7 KO and WT mice; however, Smad7 KO mice exhibited more severe renal functional injury as shown by increased proteinuria and reduced renal function (both p<0.05) when compared with Smad7 WT mice. Enhanced renal injury in Smad7 KO mice was associated with more progressive renal fibrosis with elevated TGF-β/Smad3 signalling. Smad7 KO mice also showed more profound renal inflammation including increased macrophage infiltration, enhanced IL-1β and TNF-α expression, and a marked activation of NF-κB signaling (all p<0.01). Further studies revealed that enhanced ANG II-mediated renal inflammation and fibrosis in Smad7 KO mice were also associated with up-regulation of Sp1 but downregulation of miR-29b expression. Taken together, the present study revealed that enhanced Sp1-TGF-β1/Smad3-NF-κB signaling and loss of miR-29 may be mechanisms by which deletion of Smad7 promotes ANG II-mediated renal fibrosis and inflammation. Thus, Smad7 may play a protective role in ANG II-induced hypertensive kidney disease.

Topics: Angiotensin II; Animals; Fibrosis; Gene Expression Regulation; Hypertension; Inflammation; Kidney; Kidney Diseases; Male; Mice; Mice, Knockout; MicroRNAs; NF-kappa B; Proteinuria; Signal Transduction; Smad3 Protein; Smad7 Protein; Sp1 Transcription Factor; Transforming Growth Factor beta

Diabetic glomerulosclerosis is the hardening of the renal glomeruli that can lead to kidney failure. In the early stage of glomerulosclerosis occur renal mesangial expansion and renal filtration dysfunction. Purple corn has been classified as a functional food and is rich in anthocyanins exerting potential disease-preventive activities. The in vitro study using human renal mesangial cells examined that anthocyanin-rich purple corn butanol fraction (PCB) can attenuate high glucose (HG)-promoted mesangial cell proliferation and matrix accumulation.. Cells were cultured for 3 days in media containing 33 mM glucose in the presence of 1-20 μg/mL PCB. In the in vivo animal study, db/db mice were treated with 10 mg/kg anthocyanin-rich polyphenolic extracts of purple corn (PCE) for 8 weeks.. HG enhanced mesangial production of the fibrosis biomarkers of collagen IV and connective tissue growth factor (CTGF), which was markedly attenuated by adding PCB. Such mesangial fibrosis entailed interleukin-8 activation via eliciting Tyk2-STAT signaling pathway. PCB dampened HG-promoted mesangial hyperplasia that appeared to be attributed to increased expression of platelet-derived growth factor. The 8-week administration of PCE lowered plasma glucose level of db/db mice and ameliorated severe albuminuria. Moreover, PCE lessened collagen fiber accumulation in kidney glomeruli and CTGF expression via retarding TGF-β signaling. Protein expressions of nephrin and podocin, key proteins for filtration barrier function of the glomerular capillary wall, were repressed by treating mice with PCE.. Purple corn may be a potent therapeutic agent for the treatment for diabetes-associated glomerulosclerosis accompanying proteinuria and kidney filtration dysfunction.

Topics: Albuminuria; Animals; Anthocyanins; Biomarkers; Blood Glucose; Cell Proliferation; Collagen Type IV; Connective Tissue Growth Factor; Diabetic Nephropathies; Fibrosis; Humans; Interleukin-8; Intracellular Signaling Peptides and Proteins; Male; Membrane Proteins; Mesangial Cells; Mice; Plant Extracts; Platelet-Derived Growth Factor; Proteinuria; Signal Transduction; STAT Transcription Factors; Transforming Growth Factor beta; TYK2 Kinase; Zea mays

TGF-β1 upregulates microRNA-192 (miR-192) in cultured glomerular mesangial cells and in glomeruli from diabetic mice. miR-192 not only increases collagen expression by targeting the E-box repressors Zeb1/2 but also modulates other renal miRNAs, suggesting that it may be a therapeutic target for diabetic nephropathy. We evaluated the efficacy of a locked nucleic acid (LNA)-modified inhibitor of miR-192, designated LNA-anti-miR-192, in mouse models of diabetic nephropathy. LNA-anti-miR-192 significantly reduced levels of miR-192, but not miR-194, in kidneys of both normal and streptozotocin-induced diabetic mice. In the kidneys of diabetic mice, inhibition of miR-192 significantly increased Zeb1/2 and decreased gene expression of collagen, TGF-β, and fibronectin; immunostaining confirmed the downregulation of these mediators of renal fibrosis. Furthermore, LNA-anti-miR-192 attenuated proteinuria in these diabetic mice. In summary, the specific reduction of renal miR-192 decreases renal fibrosis and improves proteinuria, lending support for the possibility of an anti-miRNA-based translational approach to the treatment of diabetic nephropathy.

Topics: Albuminuria; Animals; Collagen; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Disease Models, Animal; Fibronectins; Fibrosis; Homeodomain Proteins; Kidney; Kruppel-Like Transcription Factors; Male; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; MicroRNAs; Oligonucleotides; Proteinuria; Repressor Proteins; Streptozocin; Transforming Growth Factor beta; Zinc Finger E-box Binding Homeobox 2; Zinc Finger E-box-Binding Homeobox 1

The immunosuppressive mammalian target of rapamycin (mTOR) inhibitors are widely used in solid organ transplantation, but their effect on kidney disease progression is controversial. mTOR has emerged as one of the main pathways regulating cell growth, proliferation, differentiation, migration, and survival. The aim of this study was to analyze the effects of delayed inhibition of mTOR pathway with low dose of everolimus on progression of renal disease and TGFβ expression in the 5/6 nephrectomy model in Wistar rats.. This study evaluated the effects of everolimus (0.3 mg/k/day) introduced 15 days after surgical procedure on renal function, proteinuria, renal histology and mechanisms of fibrosis and proliferation.. Everolimus treated group (EveG) showed significantly less proteinuria and albuminuria, less glomerular and tubulointerstitial damage and fibrosis, fibroblast activation cell proliferation, when compared with control group (CG), even though the EveG remained with high blood pressure. Treatment with everolimus also diminished glomerular hypertrophy. Everolimus effectively inhibited the increase of mTOR developed in 5/6 nephrectomy animals, without changes in AKT mRNA or protein abundance, but with an increase in the pAKT/AKT ratio. Associated with this inhibition, everolimus blunted the increased expression of TGFβ observed in the remnant kidney model.. Delayed mTOR inhibition with low dose of everolimus significantly prevented progressive renal damage and protected the remnant kidney. mTOR and TGFβ mRNA reduction can partially explain this anti fibrotic effect. mTOR can be a new target to attenuate the progression of chronic kidney disease even in those nephropathies of non-immunologic origin.

Topics: Analysis of Variance; Animals; Blotting, Western; Chromatography, High Pressure Liquid; Creatinine; Everolimus; Immunohistochemistry; Kidney; Nephrectomy; Proteinuria; Rats; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Sirolimus; Spectrophotometry; TOR Serine-Threonine Kinases; Transforming Growth Factor beta

Multiple transforming growth factor (TGF)-β-induced fibrogenic signals have been described in vitro. To evaluate mechanisms in vivo, we used an adriamycin nephropathy model in 129x1/Svj mice that display massive proteinuria by days 5 to 7 and pathological findings similar to human focal segmental glomerulosclerosis by day 14. TGF-β mRNA expression increased after day 7 along with nuclear translocation of the TGF-β receptor-specific transcription factor Smad3. Inhibiting TGF-β prevented both pathological changes and type-I collagen and fibronectin mRNA expression, but proteinuria persisted. Renal Akt was phosphorylated in adriamycin-treated mice, suggesting PI3-kinase activation. Expression of mRNA for the p110γ isozyme of PI3-kinase was specifically increased and p110γ colocalized with nephrin by immunohistochemistry early in disease. Nephrin levels subsequently decreased. Inhibition of p110γ by AS605240 preserved nephrin expression and prevented proteinuria. In cultured podocytes, adriamycin stimulated p110γ expression. AS605240, but not a TGF-β receptor kinase inhibitor, prevented adriamycin-induced cytoskeletal disorganization and apoptosis, supporting a role for p110γ in podocyte injury. AS605240, at a dose that decreased proteinuria, prevented renal collagen mRNA expression in vivo but did not affect TGF-β-stimulated collagen induction in vitro. Thus, PI3-kinase p110γ mediates initial podocyte injury and proteinuria, both of which precede TGF-β-mediated glomerular scarring.

Topics: Animals; Apoptosis; Cells, Cultured; Class I Phosphatidylinositol 3-Kinases; Collagen Type I; Disease Models, Animal; Doxorubicin; Fibronectins; Fibrosis; Glomerulosclerosis, Focal Segmental; Immunohistochemistry; Kidney; Male; Membrane Proteins; Mice; Mice, 129 Strain; Phosphorylation; Podocytes; Protein Kinase Inhibitors; Proteinuria; Proto-Oncogene Proteins c-akt; Receptors, Transforming Growth Factor beta; RNA, Messenger; Signal Transduction; Smad3 Protein; Time Factors; Transforming Growth Factor beta; Up-Regulation

This study examined the effects of anti-TGF-β antibody (1D11) therapy in Dahl S (S) rats fed a 4% NaCl diet. Baseline renal expression of TGF-β1 and the degree of injury were lower in female than male S rats maintained on a 0.4% NaCl diet. 4% NaCl diet increased mean arterial pressure (MAP), proteinuria, and renal injury to the same extent in both male and female S rats. Chronic treatment with 1D11 had renoprotective effects in both sexes. The ability of 1D11 to oppose the development of proteinuria when given alone or in combination with antihypertensive agents was further studied in 6-wk-old female S rats, since baseline renal injury was less than that seen in male rats. 1D11, diltiazem, and hydrochlorothiazide (HCT) attenuated the development of hypertension, proteinuria, and glomerular injury. 1D11 had no additional effect when given in combination with these antihypertensive agents. We also explored whether 1D11 could reverse renal injury in 9-wk-old male S rats with preexisting renal injury. MAP increased to 197 ± 4 mmHg and proteinuria rose to >300 mg/day after 3 wk on a 4% NaCl diet. Proteinuria was reduced by 30-40% in rats treated with 1D11, HCT, or captopril + 1D11, but the protective effect was lost in rats fed the 4% NaCl diet for 6 wk. Nevertheless, 1D11, HCT, and captopril + 1D11 still reduced renomedullary and cardiac fibrosis. These results indicate that anti-TGF-β antibody therapy reduces renal and cardiac fibrosis and affords additional renoprotection when given in combination with various antihypertensive agents in Dahl S rats.

Topics: Acute Kidney Injury; Animals; Antibodies, Anti-Idiotypic; Antihypertensive Agents; Blood Pressure; Captopril; Diltiazem; Disease Models, Animal; Female; Fibrosis; Hydrochlorothiazide; Hypertension; Male; Proteinuria; Rats; Rats, Inbred Dahl; Sex Characteristics; Sodium Chloride, Dietary; Transforming Growth Factor beta

Obstructive nephropathy is a leading cause of CKD in children. The assessment of severity of renal impairment and the prediction of which children will progress to renal failure are, however, challenging.. This case-control study measured the urinary excretion of candidate biomarkers in 27 prevalent case-patients with posterior urethral valves (PUVs) and 20 age-matched controls, correlated their urinary concentration with GFR, and analyzed receiver-operating characteristic (ROC) curve and regression analyses to assess their performance as tests for low GFR.. The median urinary protein-to-creatinine ratio was higher in children with PUV (45 g/mol; range, 5-361 g/mol) than in controls (7 g/mol; range, 3-43 g/mol) (P<0.01) and correlated inversely with renal function (r = -0.44; P<0.05). In whole urine, excretion of aquaporin-2 was significantly decreased, whereas that of TGFβ and L1 cell adhesion molecule (L1CAM) was significantly increased. Whole-urine TGFβ excretion correlated inversely with GFR (r = -0.53; P<0.05). As tests for low GFR, whole-urine TGFβ, L1CAM, and urinary protein-to-creatinine ratio performed best, with areas under the ROC curves of 0.788, 0.795, and 0.814, respectively. By linear regression analysis, whole-urine TGFβ, L1CAM, and urinary protein-to-creatinine ratio were associated with low GFR in the case-patients.. Candidate biomarkers of obstructive nephropathy can be readily measured in whole urine and in urine exosomes. In boys with PUV, these biomarkers correlate with GFR.

Topics: Adolescent; Antigens, CD; Aquaporin 2; Area Under Curve; beta Catenin; Biomarkers; Cadherins; Case-Control Studies; Child; Child, Preschool; Creatinine; Disease Progression; Exosomes; Feasibility Studies; Glomerular Filtration Rate; Humans; Infant; Kidney; Kidney Diseases; Kidney Failure, Chronic; Linear Models; Logistic Models; Male; Neural Cell Adhesion Molecule L1; Predictive Value of Tests; Proteinuria; Proteomics; ROC Curve; Transforming Growth Factor beta; TRPV Cation Channels; Urethral Obstruction; Urinalysis; Vacuolar Proton-Translocating ATPases

The olfactomedin domain proteins Olfm-1 and myocilin are expressed in podocytes. Myocilin stimulates the formation of focal contacts and actin stress fibres in podocytes and other cell types, effects that are mediated through the Wnt signalling pathway. Here, we tested if the expression of both proteins is modified during puromycin aminonucleoside (PAN) nephrosis, which leads to structural changes in the actin cytoskeleton of podocytes.. Rats were treated with PAN, and the effectiveness of treatment was analysed by electron microscopy of podocytes and protein detection in the urine. The expression of Olfm-1 and myocilin was studied by immunohistochemistry, western blot analysis of glomerular proteins and real-time RT-PCR of glomerular proteins. In parallel experiments, the expression of Olfm-1 was studied in cultured podocytes treated with dexamethasone, TGF-β, TNF-α and PAN.. Between Days 5 and 22 after treatment, the amounts of the BMZ and BMY splice variants of Olfm-1 and their mRNA were markedly elevated in proteins and mRNA from isolated glomeruli. Immunohistochemistry showed that the expression of Olfm-1 was confined to podocytes. Essentially, comparable results were obtained for myocilin. The BMZ variant of Olfm-1 appeared to be secreted from podocytes and was found in high amounts in urine of treated animals. Treatment of cultured podocytes with dexamethasone and PAN caused an increase in Olfm-1 expression, while treatment with recombinant Olfm-1 increased the formation of actin stress fibres.. Olfm-1 and myocilin are markedly induced in podocytes during PAN nephrosis and appear to be involved in the processes that govern the reorganization of the actin cytoskeleton during podocyte repair.

Topics: Animals; Blotting, Western; Cells, Cultured; Cytoskeletal Proteins; Dexamethasone; Extracellular Matrix Proteins; Eye Proteins; Glycoproteins; Humans; Immunoenzyme Techniques; Male; Nephrosis; Podocytes; Proteinuria; Puromycin Aminonucleoside; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Our recent in vitro study demonstrated peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist potentiated the anti-inflammatory effect of angiotensin receptor blocker (ARB) in tubular epithelial cell under milieu mimicking IgA nephropathy (IgAN). Here we studied the therapeutic effect of combining a PPAR-γ agonist, rosiglitazone (Ros), with an ARB, losartan (Los), in experimental IgAN induced in Lewis rats by oral and intravenous immunization with bovine gamma-globulin (BGG). The rats were randomly divided into six groups: control, IgAN, IgAN with unilateral nephrectomy (IgAN/1K), and IgAN/1K receiving Ros, Los, or Ros + Los. Medication was given 1 week after nephrectomy until killing. Rats developing IgAN had hematuria, mesangial hypercellularity with IgA deposition, glomerular damage, and tubulointerstitial infiltration of CD25+ leukocytes accompanied by increased renal expression of TGF-β, AngII receptor subtype-1 (ATR1) and ICAM-1. The renal histopathology, albuminuria, and renal expression of TGF-β, ATR1 and ICAM-1 worsened with unilateral nephrectomy. Ros or Los reduced the renal expression of PCNA, TGF-β, ATR1, and ICAM-1 in IgAN rats with nephrectomy. Despite no difference between rats treated with monotherapy, combined therapy offered additive effect with decreased renal expression of TGF-β, ATR1 and ICAM-1 and attenuation of renal injury. Our animal study suggests combined PPAR-γ agonist and ARB holds promise for future therapy for IgAN.

Topics: Analysis of Variance; Angiotensin II Type 1 Receptor Blockers; Animals; Blood Pressure; Drug Therapy, Combination; gamma-Globulins; Glomerulonephritis, IGA; Intercellular Adhesion Molecule-1; Kidney; Leukocytes, Mononuclear; Losartan; Mesangial Cells; Nephrectomy; PPAR gamma; Proteinuria; Rats; Rats, Inbred Lew; Receptor, Angiotensin, Type 1; Renin-Angiotensin System; Rosiglitazone; Thiazolidinediones; Transforming Growth Factor beta

Cilnidipine, an N/L-type calcium channel blocker, has been reported to inhibit sympathetic nerve activity and has a greater renoprotective effect than L-type calcium channel blockers. To investigate the hypothesis that cilnidipine might ameliorate advanced hypertensive nephropathy and inhibit the renal renin-angiotensin-aldosterone system, cilnidipine (1 mg per kg per day) or amlodipine (1 mg per kg per day) was administered to uninephrectomized deoxycorticosterone (DOCA)-salt hypertensive rats (DOCA-salt) for 4 weeks by gavage. Although the blood pressure in the DOCA-salt group was higher than that of control, neither cilnidipine nor amlodipine had any effect on the increase in blood pressure in the DOCA-salt group. The DOCA (40 mg per kg per week, subcutaneously (s.c.)) and salt (1% NaCl in drinking water) treatment significantly aggravated the levels of urinary protein excretion and creatinine clearance and increased glomerulosclerosis and collagen deposition in the tubulointerstitial area of the kidney. These effects were attenuated by cilnidipine treatment. Reverse transcription-polymerase chain reaction analysis revealed that the renal expression of mRNA for collagen I/IV and transforming growth factor-β was enhanced in the DOCA-salt group and that the overexpression of these molecules was suppressed by cilnidipine. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-derived superoxide production in the kidney and urinary norepinephrine excretion, which were enhanced in the DOCA-salt group, were suppressed by cilnidipine. Cilnidipine also decreased the activity and expression of angiotensin-converting enzyme (ACE) and the aldosterone concentration in the renal homogenate. Although neither cilnidipine nor amlodipine had any effect on the increased blood pressure in the DOCA-salt group, these renal changes were not induced by treatment with amlodipine. In conclusion, cilnidipine inhibited renal dysfunction, sympathetic nerve activity and renal renin-angiotensin-aldosterone system in the DOCA-salt group.

Topics: Amlodipine; Animals; Calcium Channel Blockers; Calcium Channels, L-Type; Calcium Channels, N-Type; Collagen; Desoxycorticosterone; Dihydropyridines; Disease Models, Animal; Hypertension; Intracellular Signaling Peptides and Proteins; Kidney; Male; Membrane Proteins; Proteinuria; Rats; Rats, Wistar; Renin-Angiotensin System; Sodium Chloride; Transforming Growth Factor beta; Treatment Outcome

We examined the contribution of transforming growth factor (TGF)-β-T-cell signaling to aldosterone (aldo)/salt-induced fibrosis in the kidneys and the hearts of FVB/N wild-type (WT) or transgenic (Tg) mice expressing a dominant-negative TGF-β type II receptor in T cells (hCD2-ΔkTβRII). Animals received aldo through osmotic minipumps and had access to either 1% NaCl (aldo/NaCl group) or tap water (vehicle group) for 4 weeks. Systolic blood pressure was measured during this period via a tail cuff. The animals were then killed, and urine, blood, kidneys and hearts were collected. Systolic blood pressure did not differ between the groups. Aldo/NaCl enhanced renal, cardiac and left ventricular weight in WT animals slightly, but only renal weight was increased in Tg animals. Urinary protein excretion was enhanced in Tg animals (fourfold) and increased further in WT (twofold) and Tg (1.8-fold) mice on aldo/NaCl treatment. Aldo/NaCl increased interstitial fibrosis in the kidneys (1.5-fold) and the hearts of WT (2.5-fold) animals. Under control conditions, Tg mouse cardiac (3.2-fold) and renal (1.7-fold) tissues were slightly more fibrotic compared with WT, and this condition was not further aggravated by aldo/NaCl. Aldo/NaCl-induced mRNA expression of renal fibronectin (10.7-fold in WT) but not of renal collagen mRNA expression (WT: Col1a1 7.7-fold; Col3a1, 3.1-fold; and Col4a1 3.3-fold) was abrogated in Tg animals. In hearts, aldo/NaCl-induced plasminogen activator inhibitor-1 mRNA (twofold) expression depended on TGF-β-T-cell signaling. Our results indicate that (i) aldo/NaCl can induce renal and cardiac damage in the absence of blood pressure changes, (ii) the elimination TGF-β-T-cell cross-talk leads to renal and cardiac fibrosis but does not exacerbate aldo/NaCl-induced damage and (iii) the pathological aldo/NaCl effect is modified, in part, by TGF-β-T-cell cross-talk.

Topics: Aldosterone; Animals; Blood Pressure; Collagen; Extracellular Matrix; Fibronectins; Fibrosis; Kidney; Mice; Mice, Transgenic; Myocardium; Organ Size; Plasminogen Activator Inhibitor 1; Proteinuria; Sodium Chloride, Dietary; T-Lymphocytes; Transforming Growth Factor beta

Growth factor Midkine (MK), which expresses on endothelial cells and renal proximal tubules, has been implicated in inflammation-related kidney diseases such as ischemic reperfusion-induced tubulointerstitial injury and diabetic nephropathy. The biological actions of MK are elicited through its chemotactic activity and chemokine-driven inflammatory pathway. Post-infectious glomerulonephritis is caused by the deposition of immune complexes into glomeruli by infiltrating a number of inflammatory cells. Therefore, we investigated whether MK might be involved in the pathogenesis of acute glomerulonephritis.. We induced endocapillary proliferative glomerulonephritis in 129/SV mice using intraperitoneal injections of a large amount of protein.. In contrast to mice deficient in MK (Mdk (-/-)), Mdk (+/+) mice induced by protein overload demonstrated more diffuse cellular proliferation in the mesangial areas and capillary lumens, eventually leading to glomerular damage and tubulointerstitial injury. This pathological observation could be attributable to neutrophil infiltration through the chemotaxis and stimulation of the MK-macrophage inflammatory protein (MIP)-2 pathway, but appeared to be due to the MK-related immunoglobulin (Ig)G deposition and C3 activation. These findings are often seen in infectious-related glomerular injury. Furthermore, the profile of MK expression was strongly consistent with that of glomerular damage and tubulointersititial injury.. This study might provide a new insight into understanding the deleterious role of MK in endocapillary proliferative glomerulonephritis induced by protein overload.

Topics: Animals; Chemokine CCL2; Chemokine CXCL2; Cytokines; Female; Glomerulonephritis; Immunoglobulin G; Kidney Glomerulus; Mice; Microscopy, Electron; Midkine; Proteinuria; Serum Albumin, Bovine; Transforming Growth Factor beta

The aim of the paper is to investigate the effects of adiponectin in diabetic nephropathy; we used an adenovirus to over-express adiponectin (Ad-Adipo) in streptozotocin (STZ)-induced diabetic rats. Animals were injected with either Ad-Adipo or control Ad-lacZ at 10 weeks after STZ treatment, and at two weeks postadenovirus injection, renal function was assessed. The degree of proteinuria was significantly reduced in Ad-Adipo rats compared with Ad-lacZ rats. Consistent with this, the mRNA expression levels of nephrin and transforming growth factor β (TGF-β) were significantly increased and decreased in the renal cortex of Ad-Adipo rats, respectively. Moreover, adiponectin over-expression in STZ rats decreased markers of endothelial dysfunction, a feature of diabetic nephropathy disease progression. Endothelin 1 (ET-1), plasminogen activator inhibitor 1 (PAI-1) and inducible nitric oxide synthase (iNOS) mRNA expression levels were significantly reduced in the renal cortex of Ad-Adipo rats, respectively. Concurrently, mRNA expression levels of endothelial nitric oxide synthase (eNOS), a positive regulator of endothelial function, were significantly increased in the renal cortex of Ad-Adipo rats. We have shown that chronic hyperadiponectinemia significantly alleviated the progression of proteinuria in early stage diabetic nephropathy. The mechanism whereby adiponectin decreases proteinuria involves an increase in nephrin expression, and an improvement of the endothelial dysfunction due to decreases in ET-1 and PAI-1, and an increase in eNOS expression in the renal cortex. Thus, over-expression of adiponectin has beneficial effects on early stage diabetic nephropathy.

Topics: Adenoviridae; Adiponectin; Animals; Body Weight; Diabetes Mellitus, Experimental; Endothelin-1; Endothelium; Gene Expression Regulation; HEK293 Cells; Humans; Kidney Cortex; Male; Membrane Proteins; Mice; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Plasminogen Activator Inhibitor 1; Proteinuria; Rats; Rats, Wistar; RNA, Messenger; Transduction, Genetic; Transforming Growth Factor beta

In glomerulonephritis (GN), an overload of free fatty acids (FFA) bound to albumin in urinary protein may induce oxidative stress in the proximal tubules. Human liver-type fatty acid-binding protein (hL-FABP) expressed in human proximal tubules, but not rodents, participates in intracellular FFA metabolism and exerts anti-oxidative effects on the progression of tubulointerstitial damage. We examined whether tubular enhancement of this anti-oxidative action modulates the progression of glomerular damage in immune-mediated GN in hL-FABP chromosomal gene transgenic (Tg) mice.. Anti-glomerular basement membrane antibody-induced glomerulonephritis (anti-GBM GN) was induced in Tg and wild-type mice (WT). Proteinuria, histopathology, polymorphonuclear (PMN) influx, expression of tubulointerstitial markers for oxidative stress 4-hydroxy-2-Nonenal (HNE) and fibrosis (α-smooth muscle actin), proximal tubular damage (Kim-1), Peroxisome Proliferator-Activated Receptor γ (PPAR γ) and inflammatory cytokines [Monocyte Chemotactic Protein-1, tumor necrosis factor-alpha (TNF-α) and Transforming growth factor beta (TGF-β)] were analyzed. The mice were also treated with an angiotensin type II receptor blocker (ARB).. The urinary protein level in Tg mice decreased significantly during the acute phase (~Day 5). Tg mice survived for a significantly longer time than WT mice, with an attenuation of tubulointerstitial damage score and expression of each tubulointerstitial damage marker observed at Day 7. Expression of inflammatory cytokines on Day 7 was higher in WT mice than Tg mice and correlated strongly with PPARγ expression in WT mice, but not in Tg mice. Interestingly, Tg mice showed insufficient PMN influx at 3 and 6 h, with simultaneous elevation of urinary L-FABP and reduction in HNE expression. The two strains of mice showed different types of glomerular damage, with mild mesangial proliferation in Tg mice and severe endothelial swelling with vascular thrombosis in WT mice. The glomerular damage in Tg mice was improved by administration of an ARB.. The present experimental model suggests that tubular enhancement of L-FABP may protect mice with anti-GBM GN from progression of both tubulointerstitial and glomerular injury.

Topics: Aldehydes; Angiotensin Receptor Antagonists; Animals; Autoantibodies; Blotting, Western; Chemokine CCL2; Cysteine Proteinase Inhibitors; Cytokines; Fatty Acid-Binding Proteins; Fatty Acids, Nonesterified; Female; Glomerulonephritis; Humans; Inflammation; Kidney Tubules, Proximal; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Inbred CBA; Mice, Transgenic; Nephritis, Interstitial; Oxidative Stress; PPAR gamma; Proteinuria; Real-Time Polymerase Chain Reaction; RNA, Messenger; Survival Rate; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

The active type of coagulation factor X (factor Xa) activates various cell-types through protease-activated receptor 2 (PAR2). We previously reported that a factor Xa inhibitor could suppress Thy-1 nephritis. Considering that fibrin deposition is observed in diabetic nephropathy as well as in glomerulonephritis, this study examined the roles of the coagulation pathway and factor Xa in the development of diabetic nephropathy using type 2 diabetic model mice. Diabetic (db/db) and normoglycemic (m+/m+) mice were immunohistochemically evaluated for their expression/deposition of PAR2, transforming growth factor (TGF)-β, fibrin, extracellular matrix (ECM) proteins, and CD31 at week 20. Significantly greater numbers of PAR2-positive cells and larger amounts of fibronectin, and collagen IV depositions were observed in the glomeruli of db/db mice than those in m+/m+ mice. Next, expression of PAR2 versus deposition of collagen IV and fibronectin was compared between week 20 and week 30, and the number of PAR2-positive cells in the glomeruli decreased in contrast with the increased accumulation of ECM proteins. In an intervention study, fondaparinux, a factor Xa inhibitor, was subcutaneously administered for ten weeks from week 10 to 20. Fondaparinux treatment significantly suppressed urinary protein, glomerular hypertrophy, fibrin deposition, expression of connective tissue growth factor, and ECM proteins deposition together with CD31-positive capillaries. These results suggest that coagulation pathway and glomerular PAR2 expression are upregulated in the early phase of diabetes, together with the increase of profibrotic cytokines expression, ECM proteins deposition and CD-31-positive vessels. Factor Xa inhibition may ameliorate glomerular neoangiogenesis and ECM accumulation in diabetic nephropathy.

Topics: Animals; Anticoagulants; Blood Coagulation; Capillaries; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Progression; Extracellular Matrix Proteins; Factor Xa; Factor Xa Inhibitors; Fibrin; Fondaparinux; Hypertrophy; Kidney; Kidney Glomerulus; Male; Mice; Mice, Obese; Platelet Endothelial Cell Adhesion Molecule-1; Polysaccharides; Proteinuria; Receptor, PAR-2; Transforming Growth Factor beta; Up-Regulation

Transforming growth factor-β (TGF-β) is key in the pathogenesis of diabetic nephropathy. Thrombospondin 1 (TSP1) expression is increased in diabetes, and TSP1 regulates latent TGF-β activation in vitro and in diabetic animal models. Herein, we investigate the effect of blockade of TSP1-dependent TGF-β activation on progression of renal disease in a mouse model of type 1 diabetes (C57BL/6J-Ins2(Akita)) as a targeted treatment for diabetic nephropathy. Akita and control C57BL/6 mice who underwent uninephrectomy received 15 weeks of thrice-weekly i.p. treatment with 3 or 30 mg/kg LSKL peptide, control SLLK peptide, or saline. The effects of systemic LSKL peptide on dermal wound healing was assessed in type 2 diabetic mice (db/db). Proteinuria (urinary albumin level and albumin/creatinine ratio) was significantly improved in Akita mice treated with 30 mg/kg LSKL peptide. LSKL treatment reduced urinary TGF-β activity and renal phospho-Smad2/3 levels and improved markers of tubulointerstitial injury (fibronectin) and podocytes (nephrin). However, LSKL did not alter glomerulosclerosis or glomerular structure. LSKL did not increase tumor incidence or inflammation or impair diabetic wound healing. These data suggest that selective targeting of excessive TGF-β activity through blockade of TSP1-dependent TGF-β activation represents a therapeutic strategy for treating diabetic nephropathy that preserves the homeostatic functions of TGF-β.

Topics: Albuminuria; Amino Acid Sequence; Animals; Creatinine; Dermis; Diabetic Nephropathies; Disease Models, Animal; Fibronectins; Inflammation; Injections, Intraperitoneal; Kidney; Mice; Mice, Inbred C57BL; Molecular Sequence Data; Peptides; Phosphorylation; Proteinuria; Signal Transduction; Smad2 Protein; Thrombospondin 1; Transforming Growth Factor beta; Wound Healing

Chronic metabolic acidosis is a common metabolic disturbance and its clinical impact can be severe and extensive. The role and the change of the intrarenal renin-angiotensin system (RAS) during metabolic acidosis are uncertain, and whether acidosis can evoke inflammation remains unclear.. Male Sprague-Dawley rats were fed with water containing 0.14 M NH(4)Cl to induce metabolic acidosis for 1 and 8 weeks, respectively. They were compared with animals fed with deionized water (control) and equimolar sodium chloride water (NaCl). Gene expression analysis of RAS components included renin, renin/prorenin receptor, angiotensinogen, angiotensin-converting enzyme (ACE), and angiotensin II type 1 and 2 receptors (AT1R and AT2R). Histological examination was also performed to detect morphological change.. Acidosis was found in 1-week NH(4)Cl-treated rats but not in the 8-week group. More than twofold proteinuria and a significant decline of glomerular filtration rate (GFR) were observed in acid-loaded rats. Compared to the control and NaCl groups, angiotensinogen, ACE, AT1R and AT2R were significantly increased in the 1-week acidosis group (all p < 0.05). Sustained increase of AT1R expression was found as NH(4)Cl was continued for 8 weeks. There was no significant change in transforming growth factor-β and nuclear factor-κB. The architecture of tubular epithelial cells was affected during our experiment.. Metabolic acidosis induced proteinuria and decline of GFR in association with activation of intrarenal RAS.

Topics: Acidosis; Ammonium Chloride; Angiotensinogen; Animals; Gene Expression; Glomerular Filtration Rate; Male; NF-kappa B; Peptidyl-Dipeptidase A; Proteinuria; Rats; Rats, Sprague-Dawley; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Renin-Angiotensin System; Time Factors; Transforming Growth Factor beta

Interleukin-6 (IL-6) and transforming growth factor-β (TGF-β) are implicated in the progression of IgA nephropathy, which is usually treated with corticosteroids.. Urinary IL-6 and TGF-β were measured in 21 proteinuric patients with IgA nephropathy, before and after treatment with corticosteroids, to estimate the activity of the disease after remission of proteinuria.. Urinary IL-6 and TGF-β levels at diagnosis were significantly higher in patients with IgA nephropathy compared to healthy subjects. TGF-β levels, were significantly higher in patients with proteinuria > 1 g/24 h and/or severe mesangial proliferation. Although a significant reduction of proteinuria was observed with corticosteroid treatment, urinary IL-6 and TGF-β levels remained elevated. Deterioration of renal function over a period of 5 years was observed in 3 patients. High urinary IL-6 levels at diagnosis represent a significant parameter distinguishing patients with progressive course in comparison to those with favorable clinical outcome (p = 0.01).. Treatment of patients with IgA nephropathy with corticosteroids is followed by remission of proteinuria but still increased urinary IL-6 and TGF-β excretion. This may be related to an ongoing inflammatory process within the kidney, and further research is required to estimate the value of urinary IL-6 and TGF-β as markers of activity of the disease.

Topics: Adolescent; Adrenal Cortex Hormones; Adult; Enzyme-Linked Immunosorbent Assay; Female; Glomerulonephritis, IGA; Humans; Interleukin-6; Kidney; Kidney Function Tests; Male; Middle Aged; Proteinuria; Transforming Growth Factor beta; Treatment Outcome; Young Adult

In the present study, we hypothesized that HIV-1-induced occult HIV-associated nephropathy (HIVAN) would become apparent in the presence of adverse host factors. To test our hypothesis, Vpr mice (which display doxycycline-dependent Vpr expression in podocytes) with two, three, and four copies of the angiotensinogen (Agt) gene (Vpr-Agt-2, Vpr-Agt-3, and Vpr-Agt-4) were administered doxycycline for 3 weeks (to develop clinically occult HIVAN) followed by doxycycline-free water during the next 3 weeks. Subsequently, renal biomarkers were measured, and kidneys were harvested for renal histology. Vpr-Agt-2 developed neither proteinuria nor elevated blood pressure, and displayed minimal glomerular and tubular lesions only, without any microcyst formation. Vpr-Agt-3 showed mild glomerular and tubular lesions and microcyst formation, whereas Vpr-Agt-4 showed moderate proteinuria, hypertension, glomerular sclerosis, tubular dilation, microcysts, and expression of epithelial mesenchymal transition markers. Vpr-Agt-4 not only displayed enhanced renal tissue expression of Agt, renin, and angiotensin-converting enzyme, but also had higher renal tissue concentrations of angiotensin II. Moreover, renal cells in Vpr-Agt-4 showed enhanced expression of transforming growth factor-β, connective tissue growth factor, and vascular endothelial growth factor. These findings indicate that adverse host factors, such as the activation of the renin-angiotensin system, promote the progression of occult HIVAN to apparent HIVAN.

Topics: AIDS-Associated Nephropathy; Angiotensin II; Angiotensinogen; Animals; Biomarkers; Blood Pressure; Connective Tissue Growth Factor; Doxycycline; Epithelial-Mesenchymal Transition; Female; Gene Dosage; Genes, vpr; Host-Pathogen Interactions; Kidney; Male; Mice; Mice, Transgenic; Peptidyl-Dipeptidase A; Phenotype; Proteinuria; Renin; Renin-Angiotensin System; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

This study was designed to determine the effects of in vivo anticubilin antisense RNA on the uptake of albumin in tubules and on the tubulointerstitial injury in adriamycin-induced proteinuric rats. Adriamycin-treated rats were subjected to intrarenal delivery of adenoviral vectors encoding empty plasmid, cubilin sense RNA expression vector pAd-CUB or anticubilin antisense RNA expression vector pAd-ACUB on day 3. On days 14 and 28, half of the rats in each group were randomly selected to be killed, and blood samples, kidney tissues and 24-hour urine were collected. The diseased rats treated with pAdEasy-ACUB showed a 60% decrease in serum creatinine and glomerular filtration rate. Interestingly, the anticubilin antisense treatment led to a marked increase in albuminuria. Antisense treatment attenuated the histologic changes on both day 14 and day 28. The antisense treatment induced more than 60% recovery of adriamycin-induced injury, accompanied with 85% knockdown in the expression of cubilin protein and markedly decreased albumin deposition. Adriamycin induced an increase in the expression of monocyte chemoattractant protein-1, transforming growth factor-β and regulated on activation in normal T-cell expressed and secreted and the number of infiltrating cells, which was reversed by the antisense treatment. Anticubilin antisense RNA delivered by an adenoviral vector ameliorates albuminuria-induced glomerulosclerosis and tubulointerstitial damage in adriamycin nephrotic rats, indicating that cubilin could be a potential therapeutic target in proteinuric nephropathy.

Topics: Adenoviridae; Albuminuria; Animals; Blotting, Western; Chemokine CCL2; Creatinine; Doxorubicin; Genetic Vectors; Glomerular Filtration Rate; Kidney Diseases; Male; Models, Animal; Proteinuria; Random Allocation; Rats; Rats, Sprague-Dawley; Receptors, Cell Surface; RNA, Antisense; Serum Albumin; Transforming Growth Factor beta

Renal fibrosis is the final common pathway of chronic kidney disease, and its progression predicts the degree of renal dysfunction. We investigated the renoprotective properties of pirfenidone in a remnant kidney model of chronic renal failure to determine its pharmacological potency compared to enalapril. Five-sixths nephrectomized rats were fed diet containing pirfenidone (approximately 700mg/kg/day) for 8weeks. Pirfenidone steadily inhibited the progression of proteinuria, but not to a significant degree. Pirfenidone prevented the elevation of plasma creatinine and blood urea nitrogen. At the end of the experiment, pirfenidone had reduced systolic blood pressure by means of its renoprotective effect. In a histological study, pirfenidone improved interstitial fibrosis in the renal cortex. These effects were supported by the suppression of the expression of TGF-beta and fibronectin in the mRNA of the kidney. In contrast, pirfenidone had little effect on the expression of alpha-smooth muscle actin, which is one of the proteins responsible for epithelial-mesenchymal transition. This property was confirmed by the TGF-beta-induced transdifferentiation observed in cultured normal rat kidney tubular epithelial NRK52E cells. These results suggest that pirfenidone improves the progression of chronic renal failure via its antifibrotic action, although pirfenidone has less effective TGF-beta-induced epithelial to mesenchymal transdifferentiation.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Cell Differentiation; Cell Line; Chronic Disease; Disease Progression; Enalapril; Epithelial Cells; Fibrosis; Kidney; Kidney Failure, Chronic; Male; Mesoderm; Nephrectomy; Proteinuria; Pyridones; Rats; Rats, Wistar; Transforming Growth Factor beta

Alport syndrome is a hereditary type IV collagen disease leading to progressive renal fibrosis, hearing loss and ocular changes. End stage renal failure usually develops during adolescence. COL4A3-/- mice serve as an animal model for progressive renal scarring in Alport syndrome. The present study evaluates the role of Discoidin Domain Receptor 1 (DDR1) in cell-matrix interaction involved in pathogenesis of Alport syndrome including renal inflammation and fibrosis. DDR1/COL4A3 Double-knockouts were compared to COL4A3-/- mice with 50% or 100% expression of DDR1, wildtype controls and to DDR1-/- COL4A3+/+ controls for over 6years. Double-knockouts lived 47% longer, mice with 50% DDR1 lived 29% longer and showed improved renal function (reduction in proteinuria and blood urea nitrogen) compared to animals with 100% DDR1 expression. Loss of DDR1 reduced proinflammatory, profibrotic cells via signaling of TGFbeta, CTGF, NFkappaB and IL-6 and decreased deposition of extracellular matrix. Immunogold-staining and in-situ hybridisation identified podocytes as major players in DDR1-mediated fibrosis and inflammation within the kidney. In summary, glomerular epithelial cells (podocytes) express DDR1. Loss of DDR1-expression in the kidney delayed renal fibrosis and inflammation in hereditary type IV collagen disease. This supports our hypothesis that podocyte-matrix interaction via collagen receptors plays an important part in progression of renal fibrosis in Alport disease. The blockade of collagen-receptor DDR1 might serve as an important new therapeutic concept in progressive fibrotic and inflammatory diseases in the future.

Topics: Animals; CD3 Complex; Collagen Type IV; Connective Tissue Growth Factor; Discoidin Domain Receptor 1; Female; Fibrosis; Humans; Immunohistochemistry; In Situ Hybridization; Kidney Glomerulus; Longevity; Male; Mice; Mice, Inbred ICR; Mice, Knockout; Microscopy, Electron; Nephritis, Hereditary; NF-kappa B; Proteinuria; Receptor Protein-Tyrosine Kinases; Reverse Transcriptase Polymerase Chain Reaction; RNA; Transforming Growth Factor beta; Urea

Kidney transplant recipients that develop signs of renal dysfunction or proteinuria one or more years after transplantation are at considerable risk for progression to renal failure. To assess the kidney at this time, a "for-cause" biopsy is performed, but this provides little indication as to which recipients will go on to organ failure. In an attempt to identify molecules that could provide this information, we used microarrays to analyze gene expression in 105 for-cause biopsies taken between 1 and 31 years after transplantation. Using supervised principal components analysis, we derived a molecular classifier to predict graft loss. The genes associated with graft failure were related to tissue injury, epithelial dedifferentiation, matrix remodeling, and TGF-beta effects and showed little overlap with rejection-associated genes. We assigned a prognostic molecular risk score to each patient, identifying those at high or low risk for graft loss. The molecular risk score was correlated with interstitial fibrosis, tubular atrophy, tubulitis, interstitial inflammation, proteinuria, and glomerular filtration rate. In multivariate analysis, molecular risk score, peritubular capillary basement membrane multilayering, arteriolar hyalinosis, and proteinuria were independent predictors of graft loss. In an independent validation set, the molecular risk score was the only predictor of graft loss. Thus, the molecular risk score reflects active injury and is superior to either scarring or function in predicting graft failure.

Topics: Biopsy; Capillaries; Disease Progression; Forecasting; Glomerular Filtration Rate; Graft Rejection; Humans; Kidney; Kidney Transplantation; Proteinuria; Renal Insufficiency; Transforming Growth Factor beta

Angiotensin receptor blockers (ARBs) or T- and L-type calcium channel blockers (CCBs) are useful for glomerular protection; however, the protective effects of combination therapy remain unclear. In this study, Dahl salt-sensitive rats were fed a high-salt diet and were treated daily with placebo, irbesartan (60 mg kg(-1)), efonidipine (30 mg kg(-1)), irbesartan (60 mg kg(-1))+efonidipine (30 mg kg(-1)), amlodipine (3 mg kg(-1)), or irbesartan (60 mg kg(-1))+amlodipine (3 mg kg(-1)) for 4 weeks. Significant reductions in systolic blood pressure were seen in the irbesartan-, efonidipine- and amlodipine-treated groups compared with the placebo-treated group; a further significant reduction was seen in the irbesartan+efonidipine-treated group compared with the irbesartan-treated group. Compared with the placebo-treated group, proteinuria was significantly lower in the irbesartan- and efonidipine-treated groups, but not in the amlodipine-treated group. Furthermore, a significant attenuation of proteinuria in the irbesartan+efonidipine-treated group compared with the irbesartan-treated group was observed; this effect was not observed in the irbesartan+amlodipine-treated group. The glomerulosclerosis index was significantly attenuated by all active treatments except amlodipine. The glomerulosclerosis index in the irbesartan+efonidipine-treated group, but not in the irbesartan+amlodipine-treated group, was significantly lower than that in the irbesartan-treated group. Significant attenuations of gene expressions of p22(phox), transforming growth factor-beta, monocyte chemoattractant protein-1 and collegen I were observed in the irbesartan- and efonidipine-treated groups, but not in the amlodipine-treated group. Values for these parameters were reduced to control levels in the irbesartan+efonidipine-treated group. Combination therapy with ARB and T- and L-type CCB might produce a powerful renal protective effect.

Topics: Amlodipine; Angiotensin II Type 1 Receptor Blockers; Animals; Biphenyl Compounds; Blood Pressure; Calcium Channel Blockers; Chemokine CCL2; Collagen Type I; Dihydropyridines; Drug Therapy, Combination; Gene Expression; Glomerulosclerosis, Focal Segmental; Hypertension; Irbesartan; Kidney Glomerulus; Male; NADPH Oxidases; Nitrophenols; Organophosphorus Compounds; Proteinuria; Rats; Rats, Inbred Dahl; Tetrazoles; Transforming Growth Factor beta

Pre-eclampsia is a disorder that results in significant feto-maternal complications with yet no definitive pharmacologic intervention. One postulated etiologic mechanism is an imbalance between circulating pro-angiogenic and anti-angiogenic factors. We investigated these factors sequentially throughout pregnancy (19-21 days) in our rat model of pre-eclampsia, which involves the imposition of excessive volume expansion.. We evaluated the status of the pro-angiogenic and anti-angiogenic factors at the following time points: 3-5, 7-10 and 17-20 days of gestation.. We have previously determined that the urinary excretion of the circulating bufodienolide, marinobufagenin, is elevated at the 3- to 5-day time period, prior to the advent of hypertension and proteinuria. At 3-5 days of pregnancy, there was no evidence of angiogenic imbalance in the normal pregnant (NP) and 'pre-eclamptic' (PDS) rats. At the 7- to 10-day time point, plasma PlGF was greater in the NP rats than in the PDS group (p < 0.05). The plasma sFlt-1/PlGF ratio in the PDS animals was greater than that in the NP rats (p < 0.05). The placental sFlt-1 and sFlt-1/PlGF ratio were greater in the PDS rats than in NP rats (p < 0.05). These changes were also present at the 17- to 20-day time point in both plasma and placenta. The administration of resibufogenin, an antagonist of marinobufagenin, early in pregnancy, prevented angiogenic imbalance.. We conclude that angiogenic imbalance plays a role in the pathogenesis of pre-eclampsia in this rat model. Furthermore, the earliest event in the pathogenetic sequence appears to be the secretion and elaboration of marinobufagenin.

Topics: Analysis of Variance; Angiogenic Proteins; Animals; Blood Pressure; Bufanolides; Creatinine; Endoglin; Female; Gestational Age; Hematocrit; Intracellular Signaling Peptides and Proteins; Models, Animal; Placenta Growth Factor; Pre-Eclampsia; Pregnancy; Pregnancy Proteins; Proteinuria; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-1

The Kallikrein-kinin system works through activation of two receptors. One constitutive, named B2 receptor (B2R) and another inducible, denominated B1 receptor (B1R). In renal fibrosis, B2R receptor activation appears to be protective, however B1R participation is unveiled. The aim of this study was to analyze how the deletion of the B1R would modify tissue responses after unilateral ureteral obstruction (UUO). For that, B1R knockout (B1KO) and wild-type mice (B1B2WT) were subjected to UUO and sacrificed at days 1, 5 and 14. Renal dysfunction was assayed by urine proteinuria/creatinine ratio and percentage of tubulointerstitial fibrosis. Kidneys were harvested at day 5 to analyze anti and pro-inflammatory molecules expression by real-time PCR. We demonstrated that at all time points, B1KO mice presented lower proteinuria/creatinine ratio from bladder urine. B1KO protection was reinforced by its lower tubular interstitial fibrosis percentage at day 14 (B1B2WT: 12.16+/-1.53% vs. B1KO: 6.73+/-1.07%, p<0.02). UUO was able to induce B1R expression and its highest transcription was achieved at day 5. At this day, B1KO had significant lower expression of pro-inflammatory molecules such as TGF-beta, MCP-1, OPN and IL-6 and higher anti-inflammatory components, as IL-10 and HO-1. Herein, we observed that B1R deletion may be an important component in renal fibrosis prevention.

Topics: Animals; Chemokine CCL2; Creatinine; Fibrosis; Gene Deletion; Heme Oxygenase-1; Interleukin-10; Interleukin-6; Kallikrein-Kinin System; Kidney; Kidney Diseases; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Proteinuria; Receptor, Bradykinin B1; Transforming Growth Factor beta; Ureteral Obstruction

Significant reduction of renal mass causes progressive deterioration of renal function and structure which is mediated by systemic and glomerular hypertension, hyperfiltration, oxidative stress, inflammation, and dyslipidemia. Niacin is known to improve lipid metabolism and exert antioxidant/anti-inflammatory actions. Therefore, we considered that niacin supplementation may attenuate oxidative stress, inflammation, and tissue injury in the remnant kidney. To this end, 56 nephrectomized [chronic kidney disease (CKD)] rats were randomly assigned to niacin-treated (50 mg x kg(-1) x day(-1) in the drinking water for 12 wk) and untreated groups. Sham-operated rats served as controls. The untreated CKD rats exhibited azotemia, hypertension, hypertriglyceridemia, proteinuria, glomerulosclerosis, tubulointerstitial damage, upregulation of MCP-1, plasminogen activator inhibitor-1 (PAI-1), transforming growth factor (TGF)-beta, cyclooxygenase (COX)-1, COX-2, and NAD(P)H oxidase (NOX-4, gp91(phox), p47(phox) and p22(phox) subunits) and activation of NF-kappaB (IkappaB phosphorylation). Niacin administration reduced MCP-1, PAI-1, TGF-beta, p47(phox), p22(phox), COX-1, and NF-kappaB activation, ameliorated hypertension, proteinuria, glomerulosclerosis, and tubulointerstitial injury. Although niacin lowered serum creatinine and raised creatinine clearance, the differences did not reach statistical significance. Thus niacin supplementation helps to attenuate histological injury and mitigate upregulation of oxidative and inflammatory systems in the remnant kidney.

Topics: Animals; Chemokine CCL2; Creatinine; Disease Models, Animal; Hypertension; Inflammation; Kidney Failure, Chronic; Male; Nephrectomy; NF-kappa B; Niacin; Oxidative Stress; Plasminogen Activator Inhibitor 1; Proteinuria; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta; Vitamin B Complex

The lymphocyte migration inhibitor FTY720 attenuates experimental hypertensive nephropathy. Infiltration with lymphocytes is found in both immune and nonimmune chronic kidney diseases. In a rat model of immune-initiated progressive glomerulosclerosis, selective inhibition of lymphocyte infiltration by FTY720 showed significant beneficial effects on renal fibrosis. To test whether this translates into hypertensive nephropathy (HN), the lymphocyte migration inhibitor was administered to rats following nephrectomy. Two days after surgery, male Wistar rats were allocated to the following groups: Sham surgery, nephrectomy (HN), and HN + FTY720 (0.3 mg/kg body wt). Therapy was continued for 6 wk. Treatment with FTY720 was found to selectively reduce blood lymphocyte counts by 85% (P < 0.001 vs. HN) and renal lymphocyte infiltration (CD-3 positive cells) by 63% (P < 0.01 vs. HN) as was anticipated. Lymphocyte depletion went along with a significant reduction in proteinuria (-28%), whereas hypertensive systemic blood pressure remained unchanged (160 +/- 5 vs. 161 +/- 5 mmHg, P = not significant). The markedly increased histological tubulointerstitial and glomerular matrix protein accumulation, collagen, laminin, and fibronectin deposition were all significantly impeded in the FTY720-treated animals. The anti-fibrotic effects of FTY720 were paralleled by significant reductions in renal transforming growth factor (TGF)-beta overexpression, macrophage infiltration, and cell proliferation. In conclusion, the lymphocyte migration inhibitor FTY720 significantly limits histological and molecular fibrosis in a model of hypertensive nephropathy without affecting increased systemic blood pressure. Prevention of renal lymphocytes' infiltration by FTY720 was followed by significant reductions in TGF-beta overexpression, macrophage infiltration, and renal cell proliferation. These results suggest that infiltrating lymphocytes play an active, profibrotic role in the progression of hypertensive renal tissue injury.

Topics: Animals; Blood Pressure; Cell Movement; Cell Proliferation; Disease Models, Animal; Extracellular Matrix; Fibrosis; Fingolimod Hydrochloride; Hypertension; Immunosuppressive Agents; Kidney; Kidney Diseases; Lymphocytes; Macrophages; Male; Nephrectomy; Propylene Glycols; Proteinuria; Rats; Rats, Wistar; Sphingosine; Transforming Growth Factor beta

Recent in-vitro studies demonstrated that dihydropyridine calcium channel blockers have direct mineralocorticoid receptor antagonistic activity. The present study was conducted to examine the effects of a dihydropyridine calcium channel blocker, azelnidipine, on aldosterone-induced oxidative stress and renal injury.. Uninephrectomized rats subjected to 6 weeks treatment with aldosterone (0.75 microg/h, subcutaneous) and 1% NaCl (in drinking water) showed higher systolic blood pressure (SBP), urinary excretion of protein (UproteinV), glomerular cell proliferation and renal interstitial fibrosis than vehicle (2% ethanol)-infused rats. Aldosterone-induced renal injury was associated with increased renal cortical content of thiobarbituric acid-reactive substances (TBARS), NAD(P)H oxidase complex formation and mRNA expression of NAD(P)H oxidase membrane components (p22 and gp91). Administration of azelnidipine [3 mg/kg per day, orally (p.o.)] markedly attenuated the aldosterone-induced increases in SBP, UproteinV, renal cortical tissues TBARS content, NAD(P)H oxidase complex formation, mRNA levels of p22 and gp91, and morphological changes. In aldosterone-infused rats, treatment with a nonspecific vasodilator, hydralazine (5 mg/kg per day in drinking water) resulted in a reduction in SBP similar to azelnidipine; however, it did not affect any renal parameters. Treatment with azelnidipine suppressed aldosterone/mineralocorticoid receptor-dependent but not mineralocorticoid receptor-independent superoxide production in cultured rat mesangial cells.. These data suggest that dihydropyridine calcium channel blockers may elicit marked amelioration of aldosterone-induced renal injury through their inhibitory effects on NAD(P)H oxidase-dependent oxidative stress.

Topics: Aldosterone; Animals; Azetidinecarboxylic Acid; Blood Pressure; Body Weight; Calcium Channel Blockers; Collagen Type IV; Connective Tissue Growth Factor; Creatinine; Dihydropyridines; Ethidium; Gene Expression; Kidney; Kidney Diseases; Male; Mesangial Cells; NADPH Oxidases; Organ Size; Proteinuria; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Thiobarbituric Acid Reactive Substances; Transforming Growth Factor beta

Recent clinical studies on chronic kidney disease (CKD) reported that renal dysfunction was a critical risk factor for cardiovascular events (CVE), which lead us to reconsider the effect of cardioprotective agents on the kidney. Glomerulonephritis, which is the major cause of CKD, is characterized by mesangial cell proliferation and extracellular matrix deposition. Nicorandil, a therapeutic drug for angina and acute heart failure, have been reported to show antiproliferative activity in mesangial cells. In this study, we first investigated the in vivo effects of nicorandil in anti-Thy1 nephritis rats. In male F344 rats, anti-Thy1 nephritis was induced by the injection of an anti-Thy1 antibody. From three days before induction, nicorandil (10, 30 mg/kg per day) was administered in the drinking water for 12 consecutive days. Anti-Thy1 nephritis resulted in a significant increase in proteinuria and glomerular mesangial cell proliferation. In nephritis rats, nicorandil (30 mg/kg per day) significantly suppressed increase in proteinuria, mesangial cell proliferation (the number of glomerular cell and glomerular area), and renal hypertrophy without affecting blood pressure. Nicorandil significantly prevented the overexpression of type I collagen, fibronectin, transforming growth factor (TGF)-beta, and platelet-derived growth factor (PDGF) mRNA. These results suggest that nicorandil may have renoprotective effects in mesangioproliferative glomerulonephritis.

Topics: Animals; Blood Pressure; Cardiotonic Agents; Cell Proliferation; Collagen Type I; Disease Models, Animal; Fibronectins; Glomerulonephritis, Membranoproliferative; Isoantibodies; Kidney Glomerulus; Male; Nicorandil; Organ Size; Platelet-Derived Growth Factor; Proteinuria; Rats; Rats, Inbred F344; Transforming Growth Factor beta

Topics: Biomarkers; Calcium-Binding Proteins; Diabetic Nephropathies; Disease Progression; Epithelial Cells; Humans; Mesoderm; Podocytes; Proteinuria; S100 Calcium-Binding Protein A4; Transforming Growth Factor beta

Activation of the thrombospondin-1 (TSP-1)-TGF-beta pathway by glucose and the relevance of TSP-1-dependent activation of TGF-beta for renal matrix expansion, renal fibrosis and sclerosis have previously been demonstrated by our group in in vivo and in vitro studies. Design and methods. We investigated renal biopsies (n = 40) and clinical data (n = 30) of patients with diabetic nephropathy. Ten kidneys without evidence of renal disease served as controls. Glomerular and cortical expression of TSP-1, p-smad2/3, fibrosis and glomerular sclerosis (PAS) were assessed by immunhistochemical staining and related with clinical data.. Glomerular (g) and cortical (c) TSP-1 were increased during diabetic nephropathy (g: 2.62 +/- 2.65; c: 4.5 +/- 4.2) compared to controls (g: 0.67 +/- 0.7; c: 1.5 +/- 1.2). P-smad2/3 was significantly increased (g: 16.7 +/- 12.9; c: 148.7 +/- 92.8) compared to controls (g: 7.1 +/- 3.6; c: 55 +/- 25; P < 0.05). TSP-1 was coexpressed with p-smad2/3 as an indicator of TGF-beta activation. TSP-1 correlated with enhanced tubulointerstitial p-smad2/3 positivity (r = 0.39 and r = 0.4, P < 0.05) and glomerular p-smad2/3 correlated with proteinuria (r = 0.35, P < 0.05).. In summary, the present study suggests a functional activity of the TSP-1/TGF-beta axis, especially in the tubulointerstitium of patients with diabetic nephropathy. The positive correlation of glomerular p-smad2/3 positivity with proteinuria further supports the importance of the TSP-1/TGF-beta system as a relevant mechanism for progression of human type-2 diabetic nephropathy.

Topics: Adult; Aged; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Fibrosis; Humans; Middle Aged; Proteinuria; Signal Transduction; Smad2 Protein; Smad3 Protein; Thrombospondin 1; Transforming Growth Factor beta

The progressive deterioration of renal function and structure resulting from renal mass reduction are mediated by a variety of mechanisms, including oxidative stress and inflammation. Melatonin, the major product of the pineal gland, has potent_antioxidant and anti-inflammatory properties, and its production is impaired in chronic renal failure. We therefore investigated if melatonin treatment would modify the course of chronic renal failure in the remnant kidney model. We studied rats followed 12 wk after renal ablation untreated (Nx group, n = 7) and treated with melatonin administered in the drinking water (10 mg/100 ml) (Nx + MEL group, n = 8). Sham-operated rats (n = 10) were used as controls. Melatonin administration increased 13-15 times the endogenous hormone levels. Rats in the Nx + MEL group had reduced oxidative stress (malondialdehyde levels in plasma and in the remnant kidney as well as nitrotyrosine renal abundance) and renal inflammation (p65 nuclear factor-kappaB-positive renal interstitial cells and infiltration of lymphocytes and macrophages). Collagen, alpha-smooth muscle actin, and transforming growth factor-beta renal abundance were all increased in the remnant kidney of the untreated rats and were reduced significantly by melatonin treatment. Deterioration of renal function (plasma creatinine and proteinuria) and structure (glomerulosclerosis and tubulointerstitial damage) resulting from renal ablation were ameliorated significantly with melatonin treatment. In conclusion, melatonin administration improves the course of chronic renal failure in rats with renal mass reduction. Further studies are necessary to define the potential usefulness of this treatment in other animal models and in patients with chronic renal disease.

Topics: Actins; Animals; Blood Pressure; Cell Movement; Collagen Type IV; Creatinine; Disease Models, Animal; Hypertension; Hypertrophy; Inflammation; Kidney; Kidney Failure, Chronic; Leukocytes; Male; Malondialdehyde; Melatonin; Nephrectomy; Oxidative Stress; Proteinuria; Rats; Rats, Sprague-Dawley; Transcription Factor RelA; Transforming Growth Factor beta; Tyrosine

Impaired glomerular endothelial integrity is pivotal in various renal diseases and depends on both the degree of glomerular endothelial injury and the effectiveness of glomerular endothelial repair. Glomerular endothelial repair is, in part, mediated by bone marrow-derived endothelial progenitor cells. Peroxisome proliferator activated receptor-gamma (PPAR-gamma) agonists have therapeutic actions independent of their insulin-sensitizing effects, including enhancement of endothelial progenitor cell function and differentiation. We evaluated the effect of PPAR-gamma agonist rosiglitazone (4 mg.kg(-1).day(-1)) on the course of anti-Thy1-glomerulonephritis in rats. Rosiglitazone limited the development of proteinuria and prevented plasma urea elevation (8.1 +/- 0.4 vs. 12.5 +/- 1.1 mmol/l, P = 0.002). Histologically, inflammatory cell influx was not affected, but rosiglitazone-treated rats did show fewer microaneurysmatic glomeruli on day 7 (26 +/- 3 vs. 41 +/- 5%, P = 0.01) and reduced activation of matrix production with reduced renal cortical transforming growth factor-beta, plasminogen activator inhibitor type 1, and fibronectin-1 mRNA expression. However, bone marrow-derived endothelial cell glomerular incorporation was not enhanced (3.1 +/- 0.4 vs. 3.6 +/- 0.3 cells/glomerular cross section; P = 0.31). Rosiglitazone treatment in nonnephritic rats did not influence proteinuria, urea, or renal histology. In conclusion, treatment with PPAR-gamma agonist rosiglitazone ameliorates the course of experimental glomerulonephritis in a nondiabetic model, but not through enhancing incorporation of bone marrow-derived endothelial cells in the glomerulus.

Topics: Aneurysm; Animals; Blood Pressure; Bone Marrow Transplantation; Cell Movement; Disease Models, Animal; Endothelial Cells; Extracellular Matrix; Fibronectins; Gene Expression; Glomerulonephritis, Membranous; Hypoglycemic Agents; Isoantibodies; Kidney Cortex; Kidney Glomerulus; Male; Membrane Proteins; Plasminogen Activator Inhibitor 1; PPAR gamma; Proteinuria; Rats; Rats, Inbred BN; Rosiglitazone; Stem Cells; Thiazolidinediones; Transforming Growth Factor beta; Urea

Proteinuria is a well-established exacerbating factor in chronic kidney disease. Although the mechanisms of albumin-induced tubulointerstitial damage have been extensively studied, the influence of proteinuria on podocytes has not been sufficiently elucidated. The present study examined the effect of albumin overload on podocytes in vivo and in vitro and explored the underlying mechanisms.. Rat podocytes were exposed to albumin overload in vivo by the intraperitoneal injection of albumin over 2 days whilst cultured podocytes were subjected to albumin in vitro. We analyzed albumin uptake, podocyte apoptosis, staining for F-actin and nephrin and involvement of TGF-beta1 and p38 MAPK cascades.. Rats administered albumin exhibited massive proteinuria and podocyte injury manifested by decreased nephrin immunostaining and foot process effacement. These abnormalities were accompanied by albumin deposition, TGF-beta1 upregulation, p38 MAPK phosphorylation and an increased number of glomerular TUNEL-positive cells. Exposure of cultured podocytes to albumin caused actin disarrangement and apoptosis. Podocyte injury was preceded by albumin uptake, induction of TGF-beta1 and phosphorylated p38 MAPK. Treatment of podocytes with anti-TGF-beta1 neutralizing antibody or SB203580 significantly reduced the albumin-induced injury.. These results indicate that albumin overload in vivo and in vitro promotes podocyte injury mainly via TGF-beta1/p38 MAPK pathways.

Topics: Animals; Cells, Cultured; Male; p38 Mitogen-Activated Protein Kinases; Podocytes; Proteinuria; Rats; Rats, Sprague-Dawley; Serum Albumin; Transforming Growth Factor beta

Clinical and experimental studies have provided evidence suggesting that statins exert renoprotective effects. To investigate the mechanisms by which statins may exert renoprotection, we utilized the hypertensive Dahl salt-sensitive (DS) rat model, which manifests cardiovascular and renal injury linked to increased angiotensin II-dependent activation of NADPH oxidase and decreased nitric oxide (NO) bioavailability. DS rats given high salt diet (4% NaCl) for 10 wk exhibited hypertension [systolic blood pressure (SBP) 200 +/- 8 vs. 150 +/- 2 mmHg in normal salt diet (0.5% NaCl), P < 0.05], glomerulosclerosis, and proteinuria (158%). This was associated with increased renal oxidative stress demonstrated by urinary 8-F(2alpha)-isoprostane excretion and NADPH oxidase activity, increased protein expression of transforming growth factor (TGF)-beta (63%) and fibronectin (181%), increased mRNA expression of the proinflammatory molecules monocyte chemoattractant protein-1 (MCP-1) and lectin-like oxidized LDL receptor-1 (LOX-1), as well as downregulation of endothelial NO synthase (eNOS) activity (-44%) and protein expression. Return to normal salt had no effect on SBP or any of the measured parameters. Atorvastatin (30 mg.kg(-1).day(-1)) significantly attenuated proteinuria and glomerulosclerosis and normalized renal oxidative stress, TGF-beta1, fibronectin, MCP-1 and LOX-1 expression, and eNOS activity and expression. Atorvastatin-treated rats showed a modest reduction in SBP that remained in the hypertensive range (174 +/- 8 mmHg). Atorvastatin combined with removal of high salt normalized SBP and proteinuria. These findings suggest that statins mitigate hypertensive renal injury by restoring the balance among NO, TGF-beta1, and oxidative stress and explain the added renoprotective effects observed in clinical studies using statins in addition to inhibitors of the renin-angiotensin system.

Topics: Animals; Atorvastatin; Biological Availability; Blood Pressure; Chemokine CCL2; Fibronectins; Heptanoic Acids; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Kidney; Kidney Failure, Chronic; NADPH Oxidases; Nitric Oxide; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Oxidative Stress; Proteinuria; Pyrroles; Rats; Rats, Inbred Dahl; RNA, Messenger; Scavenger Receptors, Class E; Transforming Growth Factor beta

In kidney disease renal proximal tubular epithelial cells (RPTEC) actively contribute to the progression of tubulointerstitial fibrosis by mediating both an inflammatory response and via epithelial-to-mesenchymal transition. Using laser capture microdissection we specifically isolated RPTEC from cryosections of the healthy parts of kidneys removed owing to renal cell carcinoma and from kidney biopsies from patients with proteinuric nephropathies. RNA was extracted and hybridized to complementary DNA microarrays after linear RNA amplification. Statistical analysis identified 168 unique genes with known gene ontology association, which separated patients from controls. Besides distinct alterations in signal-transduction pathways (e.g. Wnt signalling), functional annotation revealed a significant upregulation of genes involved in cell proliferation and cell cycle control (like insulin-like growth factor 1 or cell division cycle 34), cell differentiation (e.g. bone morphogenetic protein 7), immune response, intracellular transport and metabolism in RPTEC from patients. On the contrary we found differential expression of a number of genes responsible for cell adhesion (like BH-protocadherin) with a marked downregulation of most of these transcripts. In summary, our results obtained from RPTEC revealed a differential regulation of genes, which are likely to be involved in either pro-fibrotic or tubulo-protective mechanisms in proteinuric patients at an early stage of kidney disease.

Topics: Aged; Apoptosis; Bone Morphogenetic Protein 7; Bone Morphogenetic Proteins; Case-Control Studies; Cell Adhesion; Cell Cycle Proteins; Cell Differentiation; Cell Proliferation; Epithelial Cells; Female; Gene Expression Profiling; Humans; Immunologic Factors; Kidney Diseases; Kidney Tubules, Proximal; Male; Middle Aged; Oligonucleotide Array Sequence Analysis; Proteinuria; Signal Transduction; Thrombospondins; Transcription Factors; Transforming Growth Factor beta

We investigated the effect of KIOM-79, 80% ethanolic extract of a new herbal prescription, on non-obese type 2 diabetic Goto-Kakizaki (GK) rats. The rats were treated orally with KIOM-79 (500 mg/kg body weight) once a day for 13 weeks to examine the long-term effects on hyperglycemia and glomerular histology as well as biochemical and functional abnormalities in kidney. As the results, we found that KIOM-79 reduced hyperglycemia (p<0.01), ameliorated insulin resistance (p<0.001), urinary protein excretion (p<0.01) and creatinine clearance (Ccr) (p<0.001), and inhibited glomerular AGE formation (p<0.001) in diabetic GK rats. We also found that KIOM-79 prevented the glomeruli enlargement, overexpression of type IV collagen (p<0.001), PKC protein (p<0.01), TGF-beta mRNA (p<0.05) and VEGF mRNA (p<0.05). Thus, based on our finding, KIOM-79 could reduce the hyperglycemia, and prevent or retard the development of diabetic nephropathy.

Topics: Administration, Oral; Animals; Blood Glucose; Collagen Type IV; Creatine; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Drug Administration Schedule; Fasting; Glycation End Products, Advanced; Herbal Medicine; Hypoglycemic Agents; Immunohistochemistry; Insulin; Insulin Resistance; Kidney Cortex; Male; Plant Extracts; Protein Kinase C; Proteinuria; Rats; Rats, Inbred Strains; RNA, Messenger; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

FTY720 is a novel immune modulator whose primary action is blood lymphocyte depletion through interaction with sphingosine-1-phosphate (S1P) receptors. The present study analyzes the effect of FTY720 on both the early mesangial cell injury and the subsequent matrix expansion phase of experimental mesangioproliferative glomerulonephritis. Disease was induced by injection of OX-7 anti-thy1 antibody into male Wistar rats. In both protocols, FTY720 administration (0.3 mg/kg body wt) resulted in a selective and very marked reduction in blood lymphocyte count. In the injury experiment, the S1P receptor modulator was given starting 5 days before and continued until 1 day after antibody injection. FTY720 did not significantly affect the degree of anti-thy1-induced mesangial cell lysis and glomerular-inducible nitric oxide production. In the matrix expansion experiment, FTY720 treatment was started 1 day after antibody injection and continued until day 7. In this protocol, the S1P modulator reduced proteinuria, histological matrix expansion, and glomerular protein expression of TGF-beta(1), fibronectin, and PAI-1. Glomerular collagen III staining intensity was decreased. FTY720 reduced markedly glomerular lymphocyte number per cross section and to a lesser degree macrophage infiltration. In conclusion, FTY720 significantly limits TGF-beta(1) overexpression and matrix protein expression following induction of acute anti-thy glomerulonephritis, involving reductions in blood and glomerular lymphocyte numbers. The results suggest that lymphocytes actively contribute to matrix expansion in experimental mesangioproliferative glomerulonephritis. Our study expands on findings on FTY720's beneficial effects on tubulointerstitial and functional disease progression previously reported in anti-thy1-induced chronic glomerulosclerosis.

Topics: Animals; Antibodies, Blocking; Blood Pressure; Body Weight; Collagen Type III; Extracellular Matrix; Fibronectins; Fingolimod Hydrochloride; Glomerulonephritis, Membranoproliferative; Heart Rate; Immunohistochemistry; Kidney Glomerulus; Leukocyte Count; Lipopolysaccharides; Male; Nitric Oxide Synthase Type II; Plasminogen Activator Inhibitor 1; Propylene Glycols; Proteinuria; Rats; Rats, Wistar; Receptors, Lysosphingolipid; Sphingosine; Thy-1 Antigens; Transforming Growth Factor beta

Chronic allograft nephropathy (CAN) still belongs to the leading causes of graft loss over the long term. The leflunomide derivative FK778 is a novel immunosuppressant with improved pharmacokinetic properties that effectively prolonged graft survival in several transplantation models. In the present study, we investigated the effects of FK778 at different phases after transplantation on the progression of CAN.. Fisher 344 kidneys were orthotopically transplanted into Lewis recipients. Recipients were treated with FK778 (5 mg/kg/day) over different time periods (early: days 0-10 only, continuous: day 0 to week 24, or late: weeks 16-24 only posttransplantation). Proteinuria was measured every 4 weeks, whereas grafts were harvested at 24 weeks posttransplantation for morphological and immunohistochemical analysis as well as transforming growth factor-beta and platelet derived growth factor-B chain expression.. Continuous treatment with FK778 ameliorated the progression of CAN, whereas late treatment reduced proteinuria and resulted in a similar grade of CAN as compared to animals with continuous treatment. In contrast, FK778 given only during the early phase after transplantation had no effect on the progression of CAN as compared to controls.. In summary, FK778 is a potent immunosuppressive drug that can delay the progression of CAN, even when given at later stages after transplantation.

Topics: Alkynes; Animals; Creatinine; Disease Models, Animal; Disease Progression; Dose-Response Relationship, Drug; Graft Rejection; Immunosuppressive Agents; Isoxazoles; Kidney; Kidney Transplantation; Male; Nitriles; Proteinuria; Proto-Oncogene Proteins c-sis; Rats; Rats, Inbred F344; Rats, Inbred Lew; RNA, Messenger; Transforming Growth Factor beta; Transplantation, Homologous

Autoimmune crescentic glomerulonephritis is characterized by severe immune response with glomerular crescentic formation and fibrosis in the kidney. Recent studies indicate that overexpression of renal Smad7 attenuates both renal fibrosis and inflammation in rat remnant kidney. However, little attention has been paid to the potential role of TGF-beta/Smad signaling in autoimmune kidney disease. This study tested the hypothesis that blocking TGF-beta signaling by overexpression of Smad7 may have a therapeutic effect in a mouse model of autoimmune crescentic glomerulonephritis that was induced in C57BL/6 x DBA/2J F1 hybrid mice by giving DBA/2J donor lymphocytes. Smad7 gene was transfected into the kidney using the ultrasound-microbubble-mediated system. Results showed that overexpression of Smad7 blocked both renal fibrosis and inflammatory pathways in terms of Smad2/3 and NF-kappaB activation (P < 0.01), thereby inhibiting alpha-smooth muscle actin; collagen I, III, and IV accumulation; and expression of inflammatory cytokines (IL-1beta and IL-6), adhesion molecule/chemokine (intercellular adhesion molecule-1, monocyte chemoattractant protein-1), and inducible nitric oxide synthase (all P < 0.01). Leukocyte infiltration (CD4(+) cells and macrophages) was also suppressed (P < 0.005). Severe histologic damage (glomerular crescent formation and tubulointerstitial injury) and functional injury including proteinuria were significantly improved (all P < 0.05). This study provides important evidence that overexpression of Smad7 may have therapeutic potential for autoimmune kidney disease.

Topics: Animals; Autoimmune Diseases; Fibrosis; Gene Transfer Techniques; Genetic Therapy; Glomerulonephritis; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Microbubbles; NF-kappa B; Proteinuria; Signal Transduction; Smad2 Protein; Smad3 Protein; Smad7 Protein; Transforming Growth Factor beta; Ultrasonics

We investigated participation of monocyte chemoattractant protein-1 (MCP-1) in tubulointerstitial fibrosis and correlation between MCP-1 and proteinuria in Wistar-Kyoto (WKY) rats with glomerulonephritis induced by anti-glomerular basement membrane (anti-GBM) antibody. WKY rats showed marked proteinuria and severe glomerular crescent formation at 7 days post antibody injection. At 28 days, tubulointerstitial fibrotic lesions were observed, followed by sustained heavy proteinuria and severe tubulointerstitial fibrosis at 56 days. Histological examination revealed that the overlapped immunoreactivities of MCP-1, rat albumin, and p65NF-kappaB were detected in the same tubular segments of nephritic kidney, and a significant positive correlation was observed between proteinuria and MCP-1 expression in the tubulointerstitial fibrosis. ED-1- and CD8-positive cells were also abundant, and there was a good correlation between monocyte/macrophage recruitment and MCP-1 expression in the tubulointerstitial area. These results suggest that MCP-1 participates in the progression of tubulointerstitial fibrosis, through massive albuminuria, which is accompanied by marked monocyte/macrophage recruitment.

Topics: Animals; Anti-Glomerular Basement Membrane Disease; Chemokine CCL2; Creatinine; Disease Models, Animal; Disease Progression; Fibrosis; Gene Expression Regulation; Kidney; Male; Nephritis, Interstitial; Proteinuria; Rats; Rats, Inbred Lew; Rats, Inbred WKY; Rats, Wistar; Species Specificity; Transforming Growth Factor beta

Chronic kidney disease (CKD) occurs in all age groups, including children. Regardless of the underlying cause, CKD is characterized by progressive scarring that ultimately affects all structures of the kidney. The relentless progression of CKD is postulated to result from a self-perpetuating vicious cycle of fibrosis activated after initial injury. We will review possible mechanisms of progressive renal damage, including systemic and glomerular hypertension, various cytokines and growth factors, with special emphasis on the renin-angiotensin-aldosterone system (RAAS), podocyte loss, dyslipidemia and proteinuria. We will also discuss possible specific mechanisms of tubulointerstitial fibrosis that are not dependent on glomerulosclerosis, and possible underlying predispositions for CKD, such as genetic factors and low nephron number.

Topics: Adolescent; Child; Chronic Disease; Disease Progression; Dyslipidemias; Female; Fibrosis; Genetic Predisposition to Disease; Humans; Hypertension, Renal; Kidney Diseases; Male; Podocytes; Polymorphism, Genetic; Proteinuria; Renin-Angiotensin System; Transforming Growth Factor beta

Hyperinsulinemia has been implicated in the development of diabetic nephropathy. In the present study we compared the renoprotective effects of the thiazolidinedione, pioglitazone (PGZ), to that of insulin in a hypertensive, obese, type II diabetic rat model. PGZ aggravated obesity and gave less glycemic control than insulin. However, renoprotection was markedly better with PZG compared to insulin as shown by lower proteinuria, improved renal function, and less histological evidence of diabetic glomerular and tubulointerstitial lesions. PZG and insulin both reduced renal accumulation of pentosidine and oxidative stress to a similar extent. In contrast, PGZ but not insulin suppressed enhanced transforming growth factor-beta (TGF-beta) expression. We further confirmed in cultured rat proximal tubular cells that insulin enhanced TGF-beta mRNA expression and protein production. Our results identify hyperinsulinemia and the attendant increase of TGF-beta expression as potential therapeutic targets in diabetes independent of glycemic control. This confirms prior clinical evidence that PZG provides renoprotection in obese, diabetic patients with nephropathy.

Topics: Animals; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Glycation End Products, Advanced; Hyperinsulinism; Hypertension, Renal; Hypoglycemic Agents; Insulin; Kidney; Male; Obesity; Oxidative Stress; Pioglitazone; Proteinuria; Rats; Rats, Inbred SHR; Rats, Inbred WKY; RNA, Messenger; Thiazolidinediones; Transforming Growth Factor beta

Evidence suggests that the progression of renal fibrosis is a reversible process. Because inflammation plays a crucial role in the development of renal injury, we examined the effect of kallikrein and activation of the kinin B2 receptor on the reversal of salt-induced inflammation and renal fibrosis in Dahl salt-sensitive (DSS) rats. Four weeks after high salt loading, when renal injury was apparent, adenovirus harboring the human tissue kallikrein gene was injected into DSS rats. To determine the role of the B2 receptor in mediating the actions of kallikrein, icatibant, a kinin B2 receptor antagonist, was infused with kallikrein gene delivery. Two weeks after adenovirus injection, salt-induced glomerular sclerosis, tubular protein cast formation, and monocyte/ macrophage accumulation in the kidney were notably reversed by kallikrein. Decreased intercellular adhesion molecule-1 expression paralleled this observation. Kallikrein gene delivery also dramatically reduced collagens I, III, and IV and reticulin deposition, accompanied by a decline in myofibroblast accumulation and transforming growth factor-beta(1) expression. Moreover, kallikrein reversed salt-induced glomerular hypertrophy and inhibited the increase in levels of the cell cycle-inhibitory proteins p21 and p27. These protective actions of kallikrein were abolished by icatibant, indicating a B2 receptor-mediated event. In addition, kallikrein protected against salt-induced renal injury by diminishing urinary protein and blood urea nitrogen levels. Furthermore, kallikrein gene delivery restored nitric oxide production and suppressed NADH oxidase activity and superoxide generation. These results indicate that tissue kallikrein, through the kinin B2 receptor, reverses salt-induced inflammation, renal fibrosis, and glomerular hypertrophy via suppression of oxidative stress.

Topics: Actins; Animals; Blood Urea Nitrogen; Collagen; Fibrosis; Genetic Therapy; Hypertrophy; Inflammation; Intercellular Adhesion Molecule-1; Kidney; Kidney Glomerulus; Male; Multienzyme Complexes; Myoblasts, Smooth Muscle; NADH, NADPH Oxidoreductases; Oxidative Stress; Proteinuria; Rats; Rats, Inbred Dahl; Reticulin; Tissue Kallikreins; Transforming Growth Factor beta

Recent studies have suggested that aldosterone plays a role in the pathogenesis of renal injury. In this study, we investigated whether local angiotensin II (Ang II) activity contributes to the progression of renal injury in aldosterone/salt-induced hypertensive rats. Uninephrectomized rats were treated with 1% NaCl in a drinking solution and one of the following combinations for 6 weeks: vehicle (2% ethanol, s.c.; n=9), aldosterone (0.75 mug/h, s.c.; n=8), aldosterone+Ang II type 1 receptor blocker olmesartan (10 mg/kg/day, p.o.; n=8), or aldosterone+olmesartan (100 mg/kg/day, p.o.; n=9). Aldosterone/salt-treated hypertensive rats exhibited severe proteinuria and renal injury characterized by glomerular sclerosis and tubulointerstitial fibrosis. Aldosterone/salt-induced renal injury was associated with augmented expression of angiotensin converting enzyme and Ang II levels in the renal cortex and medullary tissues. Renal cortical and medullary mRNA expression of transforming growth factor-beta (TGF-beta) and connective tissue growth factor (CTGF) as well as the collagen contents were increased in aldosterone/salt-treated hypertensive rats. Treatment with olmesartan (10 or 100 mg/kg/day) had no effect on blood pressure but attenuated proteinuria in a dose-dependent manner. Olmesartan at 10 mg/kg/day tended to decrease renal cortical and medullary Ang II levels, TGF-beta and CTGF expression, and collagen contents; however, these changes were not significant. On the other hand, an ultrahigh dose of olmesartan (100 mg/kg/day) significantly decreased these values and ameliorated renal injury. These data suggest that augmented local Ang II activity contributes, at least partially, to the progression of aldosterone/salt-dependent renal injury.

Topics: Aldosterone; Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Animals; Blood Pressure; Body Weight; Collagen; Connective Tissue Growth Factor; Creatine; Hypertension; Imidazoles; Immediate-Early Proteins; Intercellular Signaling Peptides and Proteins; Kidney; Male; Nephrectomy; Organ Size; Peptidyl-Dipeptidase A; Proteinuria; Rats; Rats, Sprague-Dawley; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Sodium Chloride; Tetrazoles; Transforming Growth Factor beta

Previous investigations have demonstrated that green tea polyphenols and partially hydrolyzed guar gum as dietary fiber have antioxidative and hypolipidemic activity, respectively, supporting their reduction of risk factors in the course of diabetic nephropathy via a hypoglycemic effect and ameliorating the decline of renal function through their combined administration to rats with subtotal nephrectomy plus streptozotocin (STZ) injection. As a further study, we examined whether (-)-epigallocatechin 3-O-gallate (EGCg), the main polyphenolic compound, could ameliorate the development of diabetic nephropathy. Rats with subtotal nephrectomy plus STZ injection were orally administrated EGCg at doses of 25, 50, and 100 mg/kg body weight/day. After a 50-day administration period, EGCg-treated groups showed suppressed hyperglycemia, proteinuria, and lipid peroxidation, although there were only weak effects on the levels of serum creatinine and glycosylated protein. Furthermore, EGCg reduced renal advanced glycation end-product accumulation and its related protein expression in the kidney cortex as well as associated pathological conditions. These results suggest that EGCg ameliorates glucose toxicity and renal injury, thus alleviating renal damage caused by abnormal glucose metabolism-associated oxidative stress involved in renal lesions of diabetic nephropathy.

Topics: Animals; Body Weight; Catechin; Cyclooxygenase 2; Diabetic Nephropathies; Fibronectins; Kidney; Male; NF-kappa B; Nitric Oxide Synthase Type II; Organ Size; Proteinuria; Rats; Rats, Wistar; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Transforming Growth Factor beta

In diabetic rats with maximal activation of RAS induced by uninephrectomy, late treatment with anti-TGFbeta antibody limited renal injury only when combined with ACE inhibitor. We investigated whether in a two-kidney diabetic model the time at which treatment started predicted the response to TGFbeta antagonist.. 27 weeks after streptozotocin injection, animals had mild proteinuria and were randomized to receive irrelevant antibody, anti-TGFbeta antibody (1D11) or enalapril till 52 weeks (early treatment). The effect of agents alone or combined was also evaluated at the time of overt proteinuria (late treatment, 52-61 weeks).. When given early, 1D11 displayed marked antihypertensive and antiproteinuric effects. Glomerulosclerosis was reduced to the extent that a remarkable percentage of glomeruli without sclerosis appeared after treatment. Podocyte number was normalized. Renoprotection of 1D11 was comparable to enalapril. Despite control of blood pressure, in late treatment single agents did not reduce proteinuria significantly. Glomerulosclerosis and podocyte loss were partially limited by 1D11 or enalapril, but full protection was achieved by combination.. Renoprotective effect of TGFbeta antagonism crucially depends on the time at which treatment started. Effectiveness of early treatment with 1D11 would indicate that TGFbeta is a major mediator of damage in early diabetes. To tackle the renal damage in the phase of advanced disease, a combined treatment with ACE inhibitor is needed.

Topics: Albuminuria; Angiotensin-Converting Enzyme Inhibitors; Animals; Antibodies; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Enalapril; Kidney Glomerulus; Male; Podocytes; Proteinuria; Rats; Rats, Sprague-Dawley; Time Factors; Transforming Growth Factor beta

The expression of TGF beta-inducible gene h3(beta ig-h3) has been used to assess the biological activity of TGF beta in the kidney. In this study, we investigated whether the urinary concentration of beta ig-h3 is associated with diabetic nephropathy in patients with Type 2 diabetes mellitus. We also evaluated the relationship between the urinary concentration of beta ig-3 and proteinuria and microalbuminuria (AER) in a normal healthy population and in Type 2 diabetes patients.. Four hundred and seventy-nine Type 2 diabetic patients without non-diabetic kidney diseases and 528 healthy control subjects were enrolled. The study subjects were divided into five groups: a non-diabetic healthy control group with normal ACR (n = 443), a non-diabetic healthy control group with microalbuminuria (n = 85), a normoalbuminuric diabetic group (n = 198), a microalbuminuric diabetic group (n = 155) and an overt proteinuria group (n = 126). Urinary levels of beta ig-h3 were measured by enzyme-linked immunosorbent assay.. (i) Urinary excretion of beta ig-h3 was significantly higher in the diabetic groups than in the controls, even in the normoalbuminuric stage (25.02 +/- 8.84 vs. 18.67 +/- 6.56, P = 0.03). In diabetic patients, urinary beta ig-h3 levels increased significantly as diabetic nephropathy advanced (25.02 +/- 8.84 vs. 34.06 +/- 24.55 vs. 169.63 +/- 57.33, P < 0.001). (ii) Proteinuria was found to be significantly correlated with urinary beta ig-h3 (healthy control; r = 0.137, P = 0.019, diabetic patients; r = 0.604, P < 0.001). ACR was also found to be significantly related with urinary beta ig-h3 in diabetic patients (r = 0.383, P = 0.006). (iii) In diabetic patients, urinary beta ig-h3 was significantly related with systolic and diastolic blood pressure (systolic blood pressure: r = 0.436, P = 0.024; diastolic blood pressure, r = 0.365, P = 0.042), total cholesterol and HbA(1c) (cholesterol: r = 0.169, P = 0.03, HbA(1c); r = 0.387, P = 0.044). Logistic regression analyses showed that urinary beta ig-h3 was associated with a significant increase in the risk of microalbuminuria and proteinuria in diabetic patients.. Longitudinal monitoring of urinary beta ig-h3 may improve the likelihood of detecting diabetic nephropathy at an earlier stage and beta ig-h3 could be a sensitive marker of diabetic kidney disease progression.

Topics: Albuminuria; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Neuropathies; Enzyme-Linked Immunosorbent Assay; Extracellular Matrix Proteins; Female; Humans; Male; Middle Aged; Proteinuria; Risk Factors; Transforming Growth Factor beta

Administration of the anti-Thy1 antibody in rats induces reversible glomerulonephritis resembling human mesangiolytic and mesangioproliferative diseases. The purpose of the present study was to design a model of irreversible glomerulosclerosis, using the anti-Thy1 antibody injection after uninephrectomy, and examine it, focusing on apoptosis in the process of progressive sclerotic changes. Wistar rats were divided into three groups: one-kidney groups (group I and III) and a two-kidney group (group II). All groups were injected with the anti-Thy1 antibody (OX-7) at day 0, and group I and III were uninephrectomized at day -6. Only group III rats were given a half dose of OX-7 as compared with group I and II. Rats were killed for histological examinations at days 7, 14 and 30. In group I, progressive glomerular lesions, such as glomerular adhesion to Bowman's capsule, crescent formation, and collapse of capillary tufts were observed at days 14 and 30. No significant differences were observed in the pathological findings between group I and III. There was a significantly higher number of glomerular terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling-positive cells in group I as compared to group II at days 7 and 14. Moreover, the glomerular expression of transforming growth factor-beta, heparan sulfate proteoglycan and chondroitin sulfate proteoglycan significantly increased in group I as compared to group II at days 7 and 14. Progressive glomerulosclerosis can be induced in the rat by a single injection of the anti-Thy1 antibody after unilateral nephrectomy. It is suggested that apoptosis and extracellular matrix accumulation play an important role in the development of glomerulosclerosis.

Topics: Animals; Apoptosis; Cell Proliferation; Chondroitin Sulfate Proteoglycans; Disease Models, Animal; Glomerulonephritis; Glomerulosclerosis, Focal Segmental; Heparan Sulfate Proteoglycans; Immunohistochemistry; In Situ Nick-End Labeling; Isoantibodies; Kidney; Male; Nephrectomy; Proteinuria; Rats; Transforming Growth Factor beta

Brain abnormalities, preceded by a systemic inflammation, develop in spontaneously hypertensive stroke-prone rats (SHRSP). In this model, we investigated whether the hydrophilic statin, rosuvastatin, influences the development of inflammation associated with brain abnormalities. Because differences in hydrophilicity/hydrophobicity contribute to the differences in statin pharmacology, we also evaluated the effects of simvastatin, a lipophilic molecule. SHRSP, fed a high-salt diet, were treated long-term with vehicle or rosuvastatin (1 and 10 mg/kg per day). Brain abnormalities developed after 40+/-5 days and after 60+/-5 days of salt loading, in vehicle-treated and in rosuvastatin-treated (1 mg/kg per day) SHRSP, respectively. After 100 days of treatment, no damage was detectable in 30% of the rats treated with the highest dose of the drug. In comparison with vehicle-treated SHRSP, rosuvastatin treatment attenuated the transcription of monocyte chemoattractant protein-1, transforming growth factor-beta1, IL-1beta, and tumor necrosis factor-alpha in the kidney, and of P-selectin in brain vessels and increased the transcription of endothelial nitric oxide synthase mRNA in the aorta. Urinary excretion of acute-phase proteins increased with time in vehicle-treated animals but remained negligible in drug-treated animals. These effects are independent of changes in physiological parameters. Treatment of SHRSP with simvastatin (2 to 20 mg/kg per day) did not exert any protective effect.. Rosuvastatin attenuates inflammatory processes associated with cerebrovascular disease.

Topics: Acute-Phase Proteins; Animals; Cerebral Arteries; Chemokine CCL2; Fluorobenzenes; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertension; Male; Nitric Oxide Synthase; Nitric Oxide Synthase Type III; P-Selectin; Proteinuria; Pyrimidines; Rats; Rats, Inbred SHR; RNA, Messenger; Rosuvastatin Calcium; Simvastatin; Sodium Chloride, Dietary; Stroke; Sulfonamides; Transcription, Genetic; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tumor Necrosis Factor-alpha; Vasculitis

Tubulointerstitial inflammation and fibrosis are hallmarks of chronic progressive renal diseases. To characterize the functional interaction between cell infiltration and matrix expansion, this study compared the immunosuppressant mycophenolate mofetil (MMF), intended as primarily anti-inflammatory intervention, the angiotensin-converting enzyme inhibitor enalapril, intended as primarily an anti-fibrotic drug, and a combination of both as anticipated anti-inflammatory/anti-fibrotic intervention. The model used was anti-thy1-induced chronic-progressive glomerulosclerosis (cGS) in the rat, where a brief anti-thy1-induced glomerular injury progresses spontaneously toward tubulointerstitial fibrosis and renal insufficiency. cGS was induced by injection of anti-thy1 antibody into uninephrectomized Wistar rats. One week after disease induction, animals were randomly assigned to the following groups: cGS, cGS plus MMF (20 mg.kg body wt(-1).day(-1)), cGS plus high-dose enalapril (12 mg.kg body wt(-1).day(-1)), and cGS plus both. At week 16 after disease induction, MMF or enalapril alone reduced signs of chronic renal disease significantly and similarly compared with the untreated cGS group. Variables measured included proteinuria, blood pressure, tubulointerstitial and glomerular matrix accumulation, expression of transforming growth factor-beta(1), fibronectin, and plasminogen activator inhibitor-1, infiltration of lymphocytes and macrophages, plasma creatinine and urea levels, and glomerular filtration rate. Combined MMF and enalapril treatment was not superior to single therapy. In conclusion, MMF slows the progression of chronic renal fibrosis and renal insufficiency as effectively as high-dose enalapril in the anti-thy1-induced chronic-progressive glomerulosclerosis model. The dual anti-inflammatory/anti-fibrotic intervention does not yield additive renoprotective effects, indicating that MMF and enalapril interfere with similar or very closely related pathways involved in progression of renal disease.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Cell Count; Blood Pressure; Body Weight; Disease Progression; Drug Interactions; Eating; Enalapril; Fibronectins; Fibrosis; Glomerulosclerosis, Focal Segmental; Immunohistochemistry; Immunosuppressive Agents; Kidney Diseases; Kidney Function Tests; Male; Mycophenolic Acid; Nephrectomy; Plasminogen Activator Inhibitor 1; Proteinuria; Rats; Rats, Wistar; Thy-1 Antigens; Transforming Growth Factor beta; Transforming Growth Factor beta1

Rats of the Milan normotensive strain develop spontaneous glomerulosclerosis, whereas those of the Milan hypertensive strain are resistant to renal disease, possibly due to intrarenal artery hypertrophy protecting from systemic hypertension. To assess the role of hemodynamic versus metabolic factors in diabetic nephropathy, we investigated whether streptozotocin-induced diabetes accelerates glomerulosclerosis in Milan normotensive and/or removes (the hemodynamic) protection in Milan hypertensive rats by reducing preglomerular vascular resistance.. Diabetic and nondiabetic Milan normotensive, hypertensive, and progenitor Wistar rats were followed for 6 months for the assessment of renal function and structure.. Proteinuria increased in nondiabetic and diabetic normotensive and, to a lesser extent, in diabetic Wistar, but not hypertensive rats. Serum creatinine increased and creatinine clearance decreased in nondiabetic and diabetic normotensive rats at 6 months. At 1.5 months, diabetic normotensive, but not hypertensive rats showed increased glomerular filtration rate and filtration fraction, suggesting glomerular hypertension. Diabetic nephropathy was detected in diabetic normotensive and Wistar, but not hypertensive rats. Glomerular extracellular matrix and TGF-beta mRNA levels increased with diabetes (and age) in normotensive, but not hypertensive rats. Arterioles and interlobular arteries showed increased media thickness in hypertensive versus normotensive rats, with diabetes reducing it only in the normotensive.. These data show that Milan hypertensive rats are not susceptible to diabetic nephropathy, at variance with glomerulosclerosis-prone Milan normotensive rats, thus indicating the importance of genetic background. Our study suggests that the nature of this (genetic) protection might be hemodynamic, with intrarenal artery hypertrophy preventing diabetes-induced loss of autoregulation.

Topics: Animals; Blood Pressure; Diabetes Mellitus, Experimental; Diabetic Nephropathies; DNA Primers; Extracellular Matrix; Hemodynamics; Hypertension; Kidney; Proteinuria; Rats; Rats, Mutant Strains; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; Transforming Growth Factor beta

To examine suppressive effects of multi-glycoside of Tripterygium wilfordii Hook. f. (GTW)on mesangial injury induced by two-injecti on of anti-Thy1. 1 monoclonal antibody(mAb) 1-22-3 in vitro.. We established the irreversible model of glomerulosclerosis with anti-Thy1. 1 mAb 1-22-3. After 42 days of oral treatment with GTW (50 mg x kg(-1) BW)and vehicle (distilled water), to observe effects of GTW on proteinuria, renal function, mesangial morphological change, and mRNA expressions of collagen type I and TGF-beta by light microscope (LM), immunofluorescence (IF), and Reverse Transcription Polymerase Chain Reaction (RT-PCR).. GTW ameliorated proteinuria (from day24 to day 42) and mesangial proliferation [total cell number, GTW group 65.67+/-3.43 vs. control group 87.02+/-2.41, P < 0.05; matrix expansion, GTW group 1.20+/-0.06 vs. control group 2.77+/-0.23, P < 0.05; alpha-smooth muscle actin(alpha-SMA) expression, GTW group 1.75+/-0.33 vs. control group 2.62+/-0.15, P < 0.05; collagen type I expression, GTW group 1.68+/-0.31 vs. control group 2.06+/-0.24, P < 0.05], moreover, significantly reduced the glomerular expression of mRNA for collagen type 1(53.5% to the control group, P < 0.05)and TGF-beta(14.7% to the control group, P < 0.05)on day 42day.. GTW can not only decrease proteinuria, but also ameliorate mesangial alterations probably by the reduction of cytokines. GTW may be a promising agent for the prevention of progressive and irreversible glomerulosclerosis.

Topics: Actinin; Animals; Collagen Type I; Female; Glomerular Mesangium; Glomerulonephritis, Membranoproliferative; Glycosides; Plants, Medicinal; Proteinuria; Rats; Rats, Wistar; RNA, Messenger; Transforming Growth Factor beta; Tripterygium

Sairei-to (TJ-114) is a Japanese herbal medicine of standardized quality, originating from traditional Chinese medicine. In the present in vivo study, we investigated the suppressive effects of TJ-114 and related drugs, Shosaiko-to (TJ-9), and Saiboku-to (TJ-96), on mesangioproliferative glomerulonephritis (MsPGN) in rats. TJ-9 is a basal prescription of TJ-96 and TJ-114. We evaluated the efficacy of these drugs on proteinuria, extracellular matrix (ECM) accumulation, and superoxide dismutase (SOD)-activity.. MsPGN in Wistar rats was induced by intravenous injection of rabbit anti-rat thymocyte serum (ATS). TJ-114, TJ-9, TJ-96 (500 mg/kg/day), or prednisolone (PSL, 2 mg/kg/day) was orally administered to the rats as drinking water from the day of ATS injection (day 0) to day 8, when rats were sacrificed and the kidney specimens were collected. Macrophage infiltration was evaluated by immunostaining for ED-1. ECM was measured by trichrome-staining, and fibronectin immunostaining. Northern blotting was performed to clarify the mRNA expression of cytokines and fibronectin. SOD-activity in the homogenate of renal cortex was also evaluated.. The amount of urinary protein was significantly decreased only in the TJ-114-treated group compared with the disease control group (p < 0.05). The number of ED-1-positive cells was significantly decreased in all the treatment groups (p < 0.05, respectively). Decreases in the trichrome-stained area were observed moderately in the TJ-114-treated group (66% of control, p < 0.001) and mildly in the PSL-treated group (76% of control, p < 0.001). The staining area of fibronectin in the glomerulus was significantly decreased in all the treated groups except PSL, and was especially suppressed in the TJ-114-treated group (45% of control, p < 0.001). Transforming growth factor (TGF) and connective tissue growth factor (CTGF) expression significantly decreased in the TJ-114-treated group to the control level (p < 0.05). TGF-beta, CTGF, and fibronectin mRNA were upregulated in the disease control group, and TJ-114 suppressed these mRNA expressions in glomeruli. The SOD-activity of renal cortex-homogenate was significantly augmented in all the treated groups except PSL, markedly in the TJ-96- and TJ-114-treated groups.. These results suggest that TJ-114 ameliorates ECM accumulation in experimental rat MsPGN, partly suppressing TGF-beta and CTGF expression through the recovery of SOD-activity.

Topics: Animals; Connective Tissue Growth Factor; Drugs, Chinese Herbal; Extracellular Matrix; Glomerulonephritis, Membranoproliferative; Humans; Immediate-Early Proteins; Intercellular Signaling Peptides and Proteins; Kidney Cortex; Macrophages; Male; Proteinuria; Rats; Rats, Wistar; RNA, Messenger; Superoxide Dismutase; Transforming Growth Factor beta; Up-Regulation

In DOCA-salt hypertension, renal kallikrein levels are increased and may play a protective role in renal injury. We investigated the effect of enhanced kallikrein levels on kidney remodeling of DOCA-salt hypertensive rats by systemic delivery of adenovirus containing human tissue kallikrein gene. Recombinant human kallikrein was detected in the urine and serum of rats after gene delivery. Kallikrein gene transfer significantly decreased DOCA- and salt-induced proteinuria, glomerular sclerosis, tubular dilatation, and luminal protein casts. Sirius red staining showed that kallikrein gene transfer reduced renal fibrosis, which was confirmed by decreased collagen I and fibronectin levels. Furthermore, kallikrein gene delivery diminished myofibroblast accumulation in the interstitium of the cortex and medulla, as well as transforming growth factor (TGF)-beta1 immunostaining in glomeruli. Western blot analysis and ELISA verified the decrease in immunoreactive TGF-beta1 levels. Kallikrein gene transfer also significantly reduced kidney weight, glomerular size, proliferating tubular epithelial cells, and macrophages/monocytes. Reduction of proliferation and hypertrophy was associated with reduced levels of the cyclin-dependent kinase inhibitor p27(Kip1), and the phosphorylation of c-Jun NH2-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK). The protective effects of kallikrein were accompanied by increased urinary nitrate/nitrite and cGMP levels, and suppression of superoxide formation. These results indicate that kallikrein protects against mineralocorticoid-induced renal fibrosis glomerular hypertrophy, and renal cell proliferation via inhibition of oxidative stress, JNK/ERK activation, and p27(Kip1) and TGF-beta1 expression.

Topics: Animals; Cell Cycle Proteins; Cell Division; Cyclic GMP; Cyclin-Dependent Kinase Inhibitor p27; Desoxycorticosterone; Disease Models, Animal; Extracellular Matrix; Extracellular Signal-Regulated MAP Kinases; Fibrosis; Gene Transfer Techniques; Genetic Therapy; Hypertension, Renal; Hypertrophy; JNK Mitogen-Activated Protein Kinases; Kallikreins; Male; Nitrates; Oxidative Stress; Proteinuria; Rats; Rats, Sprague-Dawley; Sodium Chloride, Dietary; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tumor Suppressor Proteins

Chronic renal disease substantially increases the risk of cardiovascular events and death. Vasopeptidase inhibitors are known to show a strong antihypertensive effect. In the present study, we investigated the nephroprotective potential of the vasopeptidase inhibitor AVE7688 beyond its antihypertensive effects in a mouse model of progressive renal fibrosis.. COL4A3 -/- mice received 25 mg AVE7688 per kg body weight. Treatment was initiated in week 4 (early) and week 7 (late). Eight mice per group were sacrificed after 7.5 or 9.5 weeks, and serum levels of urea, systemic blood pressure, and proteinuria were measured. Renal tissue was investigated by routine histology, electron microscopy, immunohistochemistry, and Western blotting. Lifespan until death from renal fibrosis was monitored.. Lifespan of treated mice increased by 143% (early therapy) and by 53% (late therapy) compared to untreated animals (172 +/- 19 vs. 109 +/- 15 vs. 71 +/- 6 days, P < 0.01). Untreated COL4A3 -/- mice did not develop severe hypertension (mean systolic blood pressure 116 +/- 14 vs. 111 +/- 9 mm Hg in wild-type mice), and both therapies mildly reduced systemic blood pressure (107 +/- 13 and 105 +/- 14 mm Hg, data not significant). AVE7688 decreased proteinuria from 12 +/- 3 g/L in untreated mice to 2 +/- 1 g/L (early) and to 4 +/- 1 g/L (late therapy, P < 0.05), as well as serum-urea from 247 +/- 27 to 57 +/- 10 and to 105 +/- 20 mmol/L (P < 0.05). Extent of fibrosis, inflammation, and profibrotic cytokines was reduced by AVE7688 therapy.. The results indicate a strong nephroprotective effect of the vasopeptidase inhibitor in this animal model of progressive renal fibrosis. Besides the antihypertensive action of AVE7688, its antifibrotic, anti-inflammatory, and antiproteinuric effects demonstrated in the present study may serve as an important therapeutic option for chronic inflammatory and fibrotic diseases in man.

Topics: Animals; Anti-Inflammatory Agents; Autoantigens; Blood Pressure; Collagen Type IV; Connective Tissue Growth Factor; Disease Models, Animal; Extracellular Matrix; Fibrosis; Heterocyclic Compounds, 3-Ring; Hypertension, Renal; Immediate-Early Proteins; Intercellular Signaling Peptides and Proteins; Life Expectancy; Mice; Mice, Inbred Strains; Mice, Mutant Strains; Nephritis, Hereditary; Prodrugs; Protease Inhibitors; Proteinuria; Transforming Growth Factor beta; Transforming Growth Factor beta1

Diabetic kidney disease has been associated with the presence of lipid deposits, but the mechanisms for the lipid accumulation have not been fully determined. In the present study, we found that db/db mice on the FVB genetic background with loss-of-function mutation of the leptin receptor (FVB-Lepr(db) mice or FVBdb/db) develop severe diabetic nephropathy, including glomerulosclerosis, tubulointerstitial fibrosis, increased expression of type IV collagen and fibronectin, and proteinuria, which is associated with increased renal mRNA abundance of transforming growth factor-beta, plasminogen activator inhibitor-1, and vascular endothelial growth factor. Electron microscopy demonstrates increases in glomerular basement membrane thickness and foot process (podocyte) length. We found that there is a marked increase in neutral lipid deposits in glomeruli and tubules by oil red O staining and biochemical analysis for cholesterol and triglycerides. We also detected a significant increase in the renal expression of adipocyte differentiation-related protein (adipophilin), a marker of cytoplasmic lipid droplets. We examined the expression of sterol regulatory element-binding protein (SREBP)-1 and -2, transcriptional factors that play an important role in the regulation of fatty acid, triglyceride, and cholesterol synthesis. We found significant increases in SREBP-1 and -2 protein levels in nuclear extracts from the kidneys of FVBdb/db mice, with increases in the mRNA abundance of acetyl-CoA carboxylase, fatty acid synthase, and 3-hydroxy-3-methylglutaryl-CoA reductase, which mediates the increase in renal triglyceride and cholesterol content. Our results indicate that in FVBdb/db mice, renal triglyceride and cholesterol accumulation is mediated by increased activity of SREBP-1 and -2. Based on our previous results with transgenic mice overexpressing SREBP-1 in the kidney, we propose that increased expression of SREBPs plays an important role in causing renal lipid accumulation, glomerulosclerosis, tubulointerstitial fibrosis, and proteinuria in mice with type 2 diabetes.

Topics: Animals; CCAAT-Enhancer-Binding Proteins; Cell Nucleus; Cholesterol; Diabetes Mellitus, Type 2; Diabetic Nephropathies; DNA-Binding Proteins; Female; Gene Expression Regulation; Hyperlipidemias; Kidney; Lipid Metabolism; Mice; Mutation; Obesity; Plasminogen Activator Inhibitor 1; Proteinuria; Receptors, Cell Surface; Receptors, Leptin; RNA, Messenger; Sterol Regulatory Element Binding Protein 1; Sterol Regulatory Element Binding Protein 2; Transcription Factors; Transforming Growth Factor beta; Triglycerides; Vascular Endothelial Growth Factor A

Mesangioproliferative glomerulonephritis is a common kidney disease and at present, there is no effective treatment. Our previous studies have demonstrated that Sairei-to can significantly prevent progression of experimental glomerulonephritis in rats. Although we have reported that the active component of Sairei-to in treatment of glomerulonephritis was Saikosaponin-d (Ssd), mechanism of Ssd in prevention of mesangioproliferative glomerulonephritis progression is still unknown. Therefore, current study examines the effects of Ssd on progression of mesangioproliferative glomerulonephritis induced by anti-Thy1 monoclonal antibody 1-22-3 (mAb 1-22-3) in uninephrectomized rats.. Eighteen female Wistar rats first received uninephrectomy and mAb 1-22-3 injection and were then divided into 3 groups: treated daily with phosphate-buffered saline (PBS), 0.6 or 1.8 mg/kg of Ssd. Urinary protein concentration and systolic blood pressure were evaluated and the kidneys were collected and subjected to histological and immunohistological evaluation. The mRNA and protein of the kidneys were extracted and subjected to reverse transcriptase polymerase chain reaction and Western blot analysis, respectively.. Ssd reduced the amount of urinary protein and systolic blood pressure. Ssd administration also decreased extracellular matrix expansion, crescentic formation as well as infiltration of macrophages and CD8+ T lymphocytes. Moreover, Ssd significantly reduced expression of transforming growth factor beta 1 (TGF-beta1) and type I collagen in the kidneys.. Ssd inhibits the progression of mesangioproliferative glomerulonephritis through reduction of the expression of TGF-beta1 and the infiltration of macrophages and CD8+ T lymphocytes.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antibodies, Monoclonal; Blood Pressure; Blotting, Western; CD8-Positive T-Lymphocytes; Collagen Type I; Disease Progression; Female; Fluorescent Antibody Technique; Gene Expression Regulation; Glomerulonephritis, Membranoproliferative; Isoantibodies; Kidney Glomerulus; Macrophages; Mesangial Cells; Oleanolic Acid; Proteinuria; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Saponins; Transforming Growth Factor beta; Transforming Growth Factor beta1

Diabetes mellitus is now the most common cause of end-stage renal failure. In this study, the effects of Hachimi-jio-gan on diabetic kidney damage in spontaneously diabetic WBN/Kob rats were examined. Oral administration of Hachimi-jio-gan to WBN/Kob rats for 25 weeks significantly suppressed urinary protein excretion. It did not affect body weight loss or blood glucose levels, whereas it reversed the increase in kidney weight of WBN/Kob rats. Hachimi-jio-gan also reduced fibronectin and transforming growth factor beta1 (TGF-beta1) protein expression in the renal cortex. Furthermore, renal lipid peroxidation levels of WBN/Kob rats given Hachimi-jio-gan were significantly lower than those of untreated controls. Renal superoxide dismutase activity was elevated by Hachimi-jio-gan treatment in a dose-dependent manner. These results suggested that Hachimi-jio-gan could prevent diabetic kidney damage by reducing renal oxidative injury and expression of fibronectin and TGF-beta1 proteins, which are all involved in the pathophysiology of diabetic nephropathy.

Topics: Administration, Oral; Animals; Blood Glucose; Blood Urea Nitrogen; Body Weight; Creatinine; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Dose-Response Relationship, Drug; Drug Administration Schedule; Drugs, Chinese Herbal; Fibronectins; Kidney Cortex; Male; Organ Size; Proteinuria; Rats; Rats, Inbred Strains; Rats, Wistar; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances; Time Factors; Transforming Growth Factor beta; Urine

Aldosterone has emerged as a deleterious hormone in the heart, with mineralocorticoid receptor (MR) blockade reducing mortality in patients with severe heart failure. There is also experimental evidence that aldosterone contributes to the development of nephrosclerosis and renal fibrosis in rodent models, but little is known of its role in clinical renal disease.. We quantified MR, serum- and glucocorticoid-regulated kinase 1 (sgk1), and mRNA expression of inflammatory mediators such as macrophage chemoattractant protein-1 (MCP-1), transforming growth factor-beta1, and interleukin-6 in 95 human kidney biopsies in patients with renal failure and mild to marked proteinuria of diverse etiologic origins. We measured renal function, serum aldosterone, urinary MCP-1 protein excretion, and the amount of chronic renal damage. Macrophage invasion was quantified by CD68 and vascularization by CD34 immunostaining. Serum aldosterone correlated negatively with creatinine clearance (P<0.01) and positively with renal scarring (P<0.05) but did not correlate with MR mRNA expression or proteinuria. Patients with heavy albuminuria (>2 g/24 h; n=15) had the most renal scarring and the lowest endothelial CD34 staining. This group showed a significant 5-fold increase in MR, a 2.5-fold increase in sgk1 expression and a significant increase in inflammatory mediators (7-fold increase in MCP-1, 3-fold increase in transforming growth factor-beta1, and 2-fold increase in interleukin-6 mRNA). Urinary MCP-1 protein excretion and renal macrophage invasion were significantly increased in patients with heavy albuminuria.. These studies support animal data linking aldosterone/MR activation to renal inflammation and proteinuria. Further studies are urgently required to assess the potential beneficial effects of MR antagonism in patients with renal disease.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Aldosterone; Biopsy; Blood Pressure; Chemokine CCL2; Female; Glomerular Basement Membrane; Humans; Immediate-Early Proteins; Interleukin-6; Ischemia; Kidney; Kidney Function Tests; Male; Middle Aged; Protein Serine-Threonine Kinases; Proteinuria; Receptors, Mineralocorticoid; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1

We investigate the role of transforming growth factor-beta (TGF-beta) in hypertension and renal failure progression in uremic rats, and whether it modulates the endothelin (ET) system.. Following renal mass reduction, uremic rats (Nx) received the pan-specific TGF-beta neutralizing antibody 1D11 (0.5 mg/kg, three times/week), the isotype control antibody 13C4 or the AT1 antagonist losartan (10 mg/kg per day) for 6 weeks.. Before treatment, the blood pressure was higher in Nx rats and increased further over time in Nx+13C4 rats. At the end of the study, Nx+13C4 rats exhibited increased serum creatinine, proteinuria and renal expression and excretion of TGF-beta1 and ET-1. ET-1 concentrations were greater in vascular and renal tissues, whereas the ETB receptor expression was reduced. Renal injuries were comprised of blood vessel hypertrophy, glomerular sclerosis, tubular atrophy and interstitial fibrosis, which was associated with increased alpha-smooth muscle actin expression. Treatment of uremic rats with the 1D11 antibody attenuated the increase in blood pressure and the decline in renal function. Losartan normalized the blood pressure and significantly attenuated the increase in serum creatinine and proteinuria. However, both treatments prevented renal TGF-beta1 and ET-1 overexpression, and prevented all renal histological injuries. The 1D11 antibody only improved ETB receptor expression.. Neutralization of TGF-beta attenuates hypertension and renal failure progression in uremic animals, in part, by preventing renal injury processes. These effects may be related to the modulation of the ET system, preventing renal ET-1 overproduction and the reduction of ETB receptor expression. Our data also suggest that TGF-beta1 is involved, at least in part, in the pathological effects related to angiotensin II in chronic renal failure.

Topics: Angiotensin II Type 1 Receptor Blockers; Animals; Antibodies; Aorta, Thoracic; Blood Pressure; Blotting, Northern; Blotting, Western; Creatinine; Endothelin-1; Gene Expression; Hypertension; Kidney; Losartan; Male; Neutralization Tests; Proteinuria; Rats; Rats, Sprague-Dawley; Receptor, Endothelin B; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta; Uremia

Albumin modified by Amadori-glucose adducts has been linked to the development of diabetic nephropathy through its ability, independent of hyperglycemia, to activate protein kinase C-beta (PKC-beta), up-regulate the transforming growth factor-beta (TGF-beta) system, and stimulate expression of extracellular matrix proteins in glomerular cells, and by the demonstration that reducing the burden of glycated albumin ameliorates renal structural and functional abnormalities in the db/db mouse.. To probe whether the salutary effects consequent to lowering glycated albumin, which include reduction of albuminuria, relate to an influence of the Amadori-modified protein on nephrin, the podocyte protein critical to regulation of protein excretion, and on the angiogenic vascular endothelial growth factor (VEGF), which induces microvascular permeability, diabetic db/db mice were treated with a small molecule that inhibits the nonenzymatic glycation of albumin.. Compared to nondiabetic db/m mice, diabetic controls exhibited increased urinary excretion of albumin and type IV collagen, elevated renal TGF-beta1 protein levels, reduced glomerular nephrin immunofluorescence and nephrin protein by immunoblotting, and increased glomerular VEGF immunostaining and renal VEGF protein content. Diabetic animals receiving test compound showed significant lowering of proteinuria, normalization of renal TGF-beta1 protein, and significant restoration of altered glomerular nephrin and VEGF expression.. The findings causally implicate the increased glycated albumin associated with the diabetic state in the abnormal renal nephrin and VEGF expression found in diabetes, thereby promoting proteinuria and glomerulosclerosis.

Topics: Albuminuria; Animals; Collagen Type IV; Diabetic Nephropathies; Fluorescent Antibody Technique; Glycated Serum Albumin; Glycation End Products, Advanced; Kidney Glomerulus; Male; Membrane Proteins; Mice; Mice, Mutant Strains; Proteinuria; Serum Albumin; Transforming Growth Factor beta; Transforming Growth Factor beta1; Vascular Endothelial Growth Factor A

In this study, the effects of inhibition of aldosterone on regression of existing hypertension-related glomerulosclerosis were investigated. Adult male Sprague Dawley rats (220 to 250 g) underwent 5/6 nephrectomy (Nx). Severity of glomerulosclerosis was assessed by renal biopsy 8 wk later, and rats were divided into four groups with equal biopsy sclerosis and then randomized by group to 4-wk treatments as follows: Control with no further treatment (CONT; n = 6); spironolactone (SP) alone (200 mg/kg per d, by gavage, n = 6); or SP combined with nonspecific triple antihypertensive drugs (TRX; reserpine, hydralazine, and hydrochlorothiazide in drinking water; SP+TRX, n = 7) or with angiotensin type 1 receptor antagonist (AT1RA; losartan in drinking water; SP+AT1RA, n = 8). When the rats were killed 12 wk after Nx, autopsy glomerulosclerosis index (SI; 0 to 4+ scale) was compared with biopsy SI in the same rats. Systolic BP was increased at 8 wk after Nx and continued to increase at 12 wk after Nx in the CONT and SP groups but not in SP+TRX- or SP+AT1RA-treated rats. Serum creatinine at 12 wk was significantly decreased in all SP-treated groups versus CONT. CONT rats had on average a 157% increase in SI from biopsy to killing at 12 wk, compared with only 84% increase in SP rats, with regression of SI in some rats. The effects on glomerulosclerosis by SP were further enhanced (when systolic BP was controlled by TRX or by AT1RA). It is concluded that inhibition of aldosterone by SP not only slows development of glomerulosclerosis but also induces regression in some rats of existing glomerulosclerosis.

Topics: Animals; Antihypertensive Agents; Blood Pressure; Disease Models, Animal; Diuretics; Glomerulonephritis; Kidney Function Tests; Losartan; Male; Nephrectomy; Proteinuria; Rats; Rats, Sprague-Dawley; Spironolactone; Transcription, Genetic; Transforming Growth Factor beta

Leptin has direct and indirect effects on renal pathophysiological characteristics. In the present study, the effects of long-term leptin infusion on the renal hemodynamics, renal excretory functions, and the expression of transforming growth factor-beta (TGF-beta), plasma endothelin-1 (ET-1) levels, and preventive effects of the angiotensin II type 1 receptor antagonist, losartan, on these renal changes were evaluated.. The study was performed by using forty Wistar albino rats. On day 0, osmotic mini-pumps filled with leptin or placebo were intraperitoneally placed under sterile conditions. The rats in Group L (Leptin group, n=15) and Group LL (Leptin-losartan group, n=15) were given recombinant murine leptin at a rate of 250 ng per hour for 28 days. Control rats (Group C, n=10) were administered placebo at the same infusion rate. The rats in Group LL were also administered losartan (10 mg kg(-1) d(-1)) perorally for 28 days. On day 28, the rats were placed in metabolic cages, and the food and water intakes were determined, and the urine was collected for 24 h. At the end of the study, systolic blood pressure (SBP), diastolic blood pressure (DBP) were determined directly from the left femoral artery, and renal blood flow (RBF) was recorded indirectly using a laser Doppler flow module.. Leptin infusion did not produce any changes in systemic arterial blood pressures and urinary flow rate. The rates of creatinine (Cr), sodium (Na), and protein excretions of the animals infused leptin were significantly increased. The urinary Cr and Na excretions were decreased, while the urinary protein excretion was normalized with the losartan treatment. The rats infused leptin had also higher circulating ET-1 levels. ET-1 levels were also reversed to the normal values with the losartan treatment. Renal TGF-beta1 expression was determined immunohistochemically, and it was more prominent in the renal tubules from the rats treated with leptin. The losartan treatment had no effect on renal TGF-beta1 expression.. Our results indicate that pathophysiological increases in plasma leptin concentrations cause enhanced renal Na, Cr and protein excretions, and high circulating ET-1 levels. Na and Cr excretions were decreased, while proteinuria and plasma ET-1 levels were normalized by losartan treatment, suggesting that renin-angiotensin system activation may have a role in leptin induced renal changes. TGF-beta1 may have an important role in leptin induced nephropathy.

Topics: Angiotensin II Type 1 Receptor Blockers; Animals; Blood Pressure; Creatinine; Kidney; Kidney Diseases; Leptin; Losartan; Proteinuria; Rats; Rats, Wistar; Renin-Angiotensin System; Sodium; Transforming Growth Factor beta; Transforming Growth Factor beta1; Urination

To observe the preventive effect of multi-glycoside of Tripterygium Wilfordii Hook. f. (GYW) on proteinuria and mesentery injury in experimental mesangial proliferative glomerulonephritis in vivo.. The reversible anti-Thyl.1 antibody glomerulo nephritis model of rats was established with monoclonal antibody 1-22-3 and intervened with GTW, and a control group was set up in the same time. Changes of 24h urinary protein excretion, serum creatinine (Scr), blood urea nitrogen (BUN), total plasma protein (TP) and glomerular morphology were observed, and the level of mRNA expression of proliferative factors, including platelet-derived growth factor-BB (PDGF-BB) and transforming growth factor-beta (TGF-beta), in renal tissue was determined.. GTW could inhibit proteinuria and mesangial injury in anti-Thyl. 1 antibody nephritis model. The PDGF-BB and TGF-beta mRNA expression in the anti-Thy1.1 antibody nephritis model rats were increased for 2.84 and 1.64 times respectively to those in the normal control group. GTW could down-regulate the over-expression of PDGF-BB mRNA by 33.1%, it was significantly different to that in the control group (P < 0.05).. GTW could reduce the proteinuria and inhibit mesangial cells proliferation and extracellular matrix deposition, these effects maybe related to the down-regulating of PDGF-BB mRNA expression.

Topics: Animals; Antibodies, Monoclonal; Becaplermin; Drugs, Chinese Herbal; Female; Glomerular Mesangium; Glomerulonephritis, Membranoproliferative; Glycosides; Phytotherapy; Plant Extracts; Platelet-Derived Growth Factor; Proteinuria; Proto-Oncogene Proteins c-sis; Random Allocation; Rats; Rats, Wistar; Thy-1 Antigens; Transforming Growth Factor beta; Tripterygium

Rats fed a high fat diet and given a low dose of streptozotocin (STZ) (35 mg/kg) develop type 2 diabetes with insulin resistance, hyperinsulinemia, moderate hyperglycemia, hyperlipidemia, and salt-sensitive hypertension. We postulated that rats with noninsulinopenic (type 2) diabetes develop lesions of diabetic nephropathy significantly more prominent than those seen in classic insulinopenic (type 1) diabetic rats.. Rats were fed regular chow or high fat diet (60% calories from fat and 70% animal fat). After 5 weeks, rats fed regular chow received vehicle (controls) or 55 mg/kg STZ (type 1 diabetes mellitus). Rats fed high fat diet received vehicle (high fat) or low dose STZ, 35 mg/kg (type 2 diabetes mellitus). Rats were sacrificed 14 weeks after STZ/vehicle injection.. Blood glucose, systolic blood pressure, and urinary protein excretion were significantly higher in both diabetes groups than in controls. Serum insulin levels (ng/mL) were higher in type 2 diabetes than in type 1 diabetes groups (0.49 +/- 0.12 vs. 0.07 +/- 0.07) (P= 0.01). Percentage of sclerosed glomeruli was significantly higher in type 2 diabetes group than in control and type 1 diabetes groups. Fibronectin expression was significantly increased in high fat, type 1 and type 2 diabetes groups compared to controls. The expression of type IV collagen, connective tissue growth factor (CTGF), and transforming growth factor-beta (TGF-beta) was significantly increased in high fat and type 2 diabetes groups compared to controls.. Rats fed a high fat diet and given a low dose of STZ developed diabetes (with normal/high insulin levels), hypertension, and proteinuria. Kidney lesions in this type 2 model appear to be more pronounced than in type 1 diabetic rats despite lower blood glucose levels and proteinuria. We present a nongenetic rat model of type 2 diabetes mellitus and nephropathy.

Topics: Animals; Blood Glucose; Blood Pressure; Body Weight; Collagen Type IV; Connective Tissue Growth Factor; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Fibronectins; Glycated Hemoglobin; Immediate-Early Proteins; Insulin; Intercellular Signaling Peptides and Proteins; Kidney; Lipids; Male; Organ Size; Proteinuria; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta

Terminal stage renal failure is the final common fate of chronic nephropathies independent of the type of initial insult. Abnormally filtered proteins have an intrinsic renal toxicity linked to their over-reabsorption by proximal tubular cells and activation of tubular-dependent pathways of interstitial inflammation and fibrosis. The functional importance of tubulointerstitial events in progressive renal disease is supported by evidence that the severity of tubular interstitial damage strongly correlates with the risk of renal failure. The present study aimed to investigate the expressive tendency of some pro-fibrosis genetic factors mRNA, including thrombospondin-1 (TSP-1), transforming growth factor-beta1 (TGF-beta1), connective tissue growth factor (CTGF) and the major component of extracellular matrix-fibronectin (FN) in renal tissues at different time points during early stage of renal lesions caused by proteinuria in bovine serum albumin (BSA) injection-induced proteinuria overload nephrotic young rats and the significance of these factors on tubulointerstitial fibrosis development.. Female young Wistar rats aged 3-4 weeks with proteinuria overload nephrosis induced by BSA (1.0 g/d) injected intraperitoneally were used as experimental models. The 80 young rats were divided into control group (n = 40) and BSA injected group (n = 40). At different time points (weeks 1, 2, 3 and 4), the urinary protein was measured by Coomassie brilliant blue colorimetric assay; the renal tissues morphologic changes were evaluated after HE staining; the P(65)/Rel-A, TSP-1, TGF-beta1 and CTGF mRNA expression in renal tissues was determined by in situ hybridization method and the FN mRNA expression was detected by Northern blot. The experimental data were evaluated by statistics software SPSS10.0.. (1) Three to four weeks after BSA injection, heavy proteinuria was observed in the rats of BSA group (week 3: 104.3 +/- 21.8 mg/24 h; week 4: 131.1 +/- 18.3 mg/24 h). The proteinuria deteriorated progressively afterwards. Histopathological examination revealed that inflammatory cells infiltrated into tubulointerstitial areas extensively, protein casts were seen in tubules and edema occurred in tubulointerstitial areas. (2) In situ hybridization showed that NF-kappaB (P(65)/Rel-A) mRNA expression was up-regulated progressively in nuclei of tubular epithelial cells, the semi-quantitative scores (at 1, 2, 3 and 4 weeks) were 2.33 +/- 0.20, 2.76 +/- 0.12, 2.96 +/- 0.19, and 3.76 +/- 0.18, respectively (F = 37.34, P < 0.01). (3) At 1 week after BSA injection, the TSP-1 mRNA expression appeared in glomeruli and increased, but was light in tubulointerstitial areas, its expressive peak was observed at week 2, and declined to mild after weeks 3 and 4. The semi-quantitative scores at different time points suggested that TSP-1 mRNA was expressed mainly in early stage of lesion in this model, then, this tendency turned to a flat roof smoothly. (4) TGF-beta1 and CTGF mRNA was up-regulated simultaneously in tubular epithelial cells (F = 8.80, P < 0.01 F = 19.41, P < 0.01). (5) Northern blotting showed that FN mRNA was considerably up-regulated at second week in the kidneys of rats in BSA group, 2.7-fold higher at week 4 than that at week 1 in BSA group rats, and was 3.6-fold higher than that of control group.. The present study suggested that NF-kappaB (P(65)/Rel-A) mRNA expression and its activity was enhanced significantly by proteinuria-loading and synchronized with high expression of TSP-1, TGF-beta1, and CTGF mRNA in the kidney, at the same time, FN mRNA was up-regulated in renal tissues and an aggravating tendency in tubulointerstitial lesions was observed in nephrotic young rats with heavy proteinuria.

Topics: Animals; Connective Tissue Growth Factor; Female; Fibronectins; Kidney; Nephrosis; NF-kappa B; Proteinuria; Rats; Rats, Wistar; RNA, Messenger; Thrombospondin 1; Transcription Factor RelA; Transforming Growth Factor beta

Chronic allograft nephropathy (CAN) is responsible for a significant proportion of graft loss. Current diagnostic methods for CAN are inadequate, and noninvasive assays for detecting allograft dysfunction/rejection and predicting long-term outcomes are a priority in transplantation.. Urine samples were collected from 48 kidney transplant recipients (KTR): 18 recipients with stable graft function (creatinine levels<2.0 mg/dL) and proteinuria of less than 500 mg/24 hr (Group 1); 18 recipients with stable graft function and proteinuria of greater than 500 mg/24 hr (Group 2); and 12 recipients with biopsy confirmed CAN. Urinary cell levels of transforming growth factor-beta1 (TGF-beta1) mRNA or epidermal growth factor (EGF) mRNA were measured using real-time quantitative PCR assay, and levels were correlated with renal allograft status. The integrity of RNA isolated from urine sediments was also assessed using the Agilent 2100 Bioanalyzer.. Urinary cell TGF-beta1 mRNA levels were higher in the CAN group compared to Group 1 (P<0.0001) or Group 2 (P<0.0001). Urinary cell EGF mRNA levels were higher in Group 1 compared to Group 2 (P<0.0001) or the CAN group (P<0.0001). There were no significant differences in the urinary cell levels of EGF mRNA between patients with greater than 500 mg/24 hr proteinuria (Group 2) and the CAN group (P=0.75).. These results demonstrate that urinary cell TGF-beta1 mRNA levels distinguish CAN patients from long-term transplant patients with stable renal function and varied levels of proteinuria. Urinary cells may be a good resource for the noninvasive diagnosis of CAN.

Topics: Adult; Creatinine; Female; Follow-Up Studies; Growth Substances; Humans; Kidney Transplantation; Male; Middle Aged; Polymerase Chain Reaction; Proteinuria; RNA, Messenger; Survivors; Time Factors; Transforming Growth Factor beta; Transforming Growth Factor beta1; Transplantation, Homologous

Although short-term treatment with anti-transforming growth factor-beta (TGF-beta) antibody (alphaT) has been shown to prevent early glomerular lesions, its long-term effects and molecular mechanisms, including intracellular signaling, remain poorly understood. We examined whether alphaT treatment induces prevention of renal insufficiency and fibrosis, and affects the TGF-beta/Smad signaling pathway in rats with chronic progressive anti-thymocyte serum (ATS) nephritis induced by repeated ATS injections on days 0 and 7.. Nephritic and non-nephritic rats were treated with either alphaT or control immunoglobulin (Ig)G twice weekly for 4 weeks from days 7 to 35 (each group, N= 21). Renal lesions and cortical expression of TGF-beta1, TGF-beta2, TGF-beta3, type II TGF-beta receptor (TbetaRII), Smads, type I collagen, and plasminogen activator inhibitor-1 were examined by immunohistochemistry, Western blot, and/or real-time reverse transcription polymerase chain reaction (RT-PCR). The binding of Smad3 in renal cortical cell nuclei to the Smad-binding element (SBE) was investigated by the electrophoretic mobility shift assay.. Nephritic rats developed heavy proteinuria, renal insufficiency, and increased extracellular matrix deposition resulting in renal fibrosis. Cortical expression levels of TGF-beta1, TGF-beta2, TbetaRII, and Smad2, but not TGF-beta3, Smad3, and Smad4 were increased. Expression and preferential localization of phosphorylated Smad2/3 in the glomerular and tubular cell nuclei, and Smad3-SBE complex-forming activity were also increased. Four-week alphaT treatment resulted in marked amelioration of chronic progressive ATS nephritis at 8 weeks.. In chronic progressive ATS nephritis, the TGF-beta/Smad signaling was up-regulated. TGF-beta blockade by alphaT suppressed the progression of renal scarring, at least in part, via inhibition of activated TGF-beta/Smad signaling.

Topics: Animals; Body Weight; Collagen; Collagen Type I; DNA-Binding Proteins; Down-Regulation; Female; Glomerulonephritis; Hydroxyproline; Immunoglobulin G; Immunotherapy; Kidney Cortex; Kidney Failure, Chronic; Male; Plasminogen Activator Inhibitor 1; Proteinuria; Rats; Rats, Wistar; RNA, Messenger; Sheep; Signal Transduction; Smad2 Protein; Smad3 Protein; Trans-Activators; Transforming Growth Factor beta

Transforming growth factor-beta (TGF-beta) modulates immune/inflammatory cells, promotes extracellular matrix (ECM) accumulation, and is increased in fibrotic organs. Here we report the effects of administering a puromycin aminonucleoside nephropathy (PAN)-specific TGF-beta neutralizing antibody on glomerulosclerosis in vivo.. Adult male Sprague-Dawley rats underwent uninephrectomy (Nx) followed by intraperitoneal PAN at weeks 2, 6, 7 and 8. Rats were treated with either high (5 mg/kg body weight) (N= 9) or low (0.5 mg/kg body weight) (N= 7) dose TGF-beta antibody intraperitoneally three times weekly until sacrifice at week 10. A PAN untreated control group (N= 7) was dosed with an isotype specific, null antibody. The nephrectomy samples were studied as normal kidney control (NL) (N= 5). Rats undergoing left kidney Nx (N= 5) only were also included as age-matched control. Renal function and morphology were assessed, and molecular studies performed.. Systolic blood pressure was increased in parallel over time in all groups (at 10 weeks, control 137 +/- 10 mm Hg; high 129 +/- 4 mm Hg; low 137 +/- 3 mm Hg) (P= NS). Both TGF-beta antibody treatments decreased renal cortex mRNA expressions similarly for TGF-beta1, TGF-beta2, and collagen III (TGF-beta1, control 0.36 +/- 0.02 mm Hg; high 0.19 +/- 0.01 mm Hg; low 0.19 +/- 0.02 mm Hg; P < 0.01 low and high vs. control; TGF-beta2, control 0.38 +/- 0.03 mm Hg; high 0.19 +/- 0.02 mm Hg; low 0.20 +/- 0.03 mm Hg; P < 0.01 low and high vs. control; and collagen III, control 0.33 +/- 0.01 mm Hg; high 0.14 +/- 0.01 mm Hg; low 0.19 +/- 0.01 mm Hg; P < 0.01 low and high vs. control; P < 0.05 low vs. high, data expressed as mRNA normalized density units vs. 18S RNA). However, only low dose TGF-beta antibody improved renal function and sclerosis measured by serum creatinine and creatinine clearance (serum creatinine, control 2.3 +/- 0.5 mg/dL; high 2.5 +/- 0.5 mg/dL; low 0.8 +/- 0.1 mg/dL; P < 0.05 low vs. control and high; creatinine clearance, control 0.44 +/- 0.11 mL/min; high 0.70 +/- 0.26 mL/min; low 1.34 +/- 0.30 mL/min; P < 0.05 low vs. control, P= NS vs. high). In parallel, sclerosis index (0 to 4+ scale) was improved in low dose (control 2.67 +/- 0.27; high 2.37 +/- 0.30; low 1.78 +/- 0.24; P < 0.05 low vs. control). This improved function and structure was linked to decreased glomerular infiltrating macrophages (0 to 4+ score, control 2.3 +/- 0.2; high 1.8 +/- 0.4; low 0.8 +/- 0.1; P < 0.01 low vs. control; P < 0.05 low vs. high; P= NS high vs. control). Further, plasminogen activator inhibitor-1 (PAI-1) mRNA expression in renal cortex was attenuated after low dose TGF-beta antibody treatment compared to control and high dose group (PAI-1/glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA ratio, NL 0.18 +/- 0.003; control 0.45 +/- 0.03; high 0.40 +/- 0.04; low 0.23 +/- 0.01; P < 0.05 low vs. control and high). Matrix metalloproteinase-9 (MMP-9) activity was maintained at higher levels in kidneys of the low dose TGF-beta antibody-treated group.. These results show an in vivo dose-response with an agent that blocks the biologic activity of TGF-beta. Higher dose of TGF-beta antibody was without beneficial effect, suggesting that TGF-beta-mediated effects on PAI-1 and macrophage influx are bimodal and closely regulated. Given that both antibody doses reduced the expression of TGF-beta isoforms and collagen III production, but only low dose ameliorated histologic sclerosis, it appears that pharmacologic effects of anti-TGF-beta antibody on matrix synthesis and degradation are not equivalent.

Topics: Animals; Antibiotics, Antineoplastic; Antibodies; Collagen; Creatinine; Dose-Response Relationship, Immunologic; Gene Expression; Glomerulosclerosis, Focal Segmental; Immunotherapy; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Plasminogen Activator Inhibitor 1; Proteinuria; Puromycin Aminonucleoside; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta; Weight Gain

Transforming growth factor-beta (TGF-beta), a profibrotic cytokine involved in many scarring processes, has to be activated extracellularly before it can bind to its receptors. Thrombospondin 1 (TSP1), a multifunctional matricellular glycoprotein, has been identified as an activator of TGF-beta in in vitro systems and during mouse postnatal development in vivo. TSP1 is expressed de novo in many inflammatory disease processes, including glomerular disease.. In this study we investigated whether peptides specifically interfering with the activation process of TGF-beta by TSP1 may be able to block activation of TGF-beta in an in vivo model of mesangial proliferative glomerulonephritis.. Continuous intravenous infusion of blocking peptide by minipumps significantly reduced expression of active TGF-beta in glomeruli on day 7 of disease as indicated by immunohistochemistry, bioassay, and activation of the TGF-beta signal transduction pathway, while total TGF-beta expression was unchanged. Inhibition of glomerular TGF-beta activation was accompanied by a decrease of glomerular extracellular matrix accumulation and proteinuria, but was without effect on mesangial cell proliferation or influx of monocytes/macrophages.. TSP1 is a major endogenous activator of TGF-beta in experimental inflammatory glomerular disease. Drugs interfering with the activation of TGF-beta by locally produced TSP1 may be considered as a future specific treatment of scarring kidney disease.

Topics: Animals; Cell Division; Extracellular Matrix; Fibrosis; Glomerular Mesangium; Glomerulonephritis; Isoantibodies; Macrophages; Peptides; Proteinuria; Rats; Rats, Sprague-Dawley; Receptors, Transforming Growth Factor beta; Thrombospondin 1; Transforming Growth Factor beta; Transforming Growth Factor beta1; Transforming Growth Factor beta2

Nephrotic syndrome has long been treated in China with two herbs, Astragalus mongholicus and Angelica sinensis, which may have antifibrotic effects.. Rats with chronic puromycin-induced nephrosis were treated with Astragalus and Angelica 3 mL/d (n = 7) or enalapril 10 mg/kg/d (n = 7). Normal control rats (n = 7) received saline rather than puromycin, and an untreated control group (n = 7) received puromycin but no treatment. After 12 weeks, stained sections of the glomerulus and tubulointerstitium were evaluated for injury. Immunohistochemistry staining measured extracellular matrix components, transforming growth factor-beta1 (TGFbeta1), osteopontin, ED-1-positive cells, and alpha-actin. TGFbeta1 mRNA was assessed by in situ hybridization. Renin, ACE activity, angiotensin, and aldosterone were measured by radioimmunoassay or colorimetry. In the untreated rats, chronic renal injury progressed to marked fibrosis at 12 weeks. Astragalus and Angelica significantly reduced deterioration of renal function and histologic damage. Expressions of type III and IV collagen, fibronectin, and laminin also decreased significantly. This anti-fibrotic effect was similar to that of enalapril. The herbs had no effect on the renin-angiotensin system but did reduce the number of ED-1-positive, and alpha-actin positive cells and expression of osteopontin compared to untreated controls. The combination of Astragalus and Angelica retarded the progression of renal fibrosis and deterioration of renal function with comparable effects of enalapril. These effects were not caused by blocking the intrarenal renin-angiotensin system, but associated with suppression of the overexpression of TGFbeta1 and osteopontin, reduction of infiltrating macrophages, and less activation of renal intrinsic cells [corrected].

Topics: Angelica sinensis; Angiotensin-Converting Enzyme Inhibitors; Animals; Antibiotics, Antineoplastic; Astragalus Plant; China; Drugs, Chinese Herbal; Enalapril; Fibrosis; Humans; Kidney; Male; Medicine, Chinese Traditional; Nephrosis; Phytotherapy; Plant Preparations; Proteinuria; Puromycin Aminonucleoside; Rats; Rats, Sprague-Dawley; Regression Analysis; Transforming Growth Factor beta; Transforming Growth Factor beta1

Peroxisome proliferator-activated receptor gamma (PPARgamma) agonists, which are known to be critical factors in lipid metabolism, have also been reported to reduce proteinuria. The mechanism and its relevance to progressive nephropathy have not been determined. The aims of this study were to assess the direct effects of a PPARgamma agonist on tubular cell albumin uptake, proinflammatory and profibrotic markers of renal pathology, using an opossum kidney model of proximal tubular cells.. Cells were exposed to pioglitazone (10 micromol/L) in the presence and absence of low-density lipoprotein (LDL) 100 microg/mL +/- exposure to albumin 1 mg/mL. Results were expressed relative to control (5 mmol/L glucose) conditions.. Pioglitazone caused a dose-dependent increase in tubular cell albumin uptake (P < 0.0001). Despite the increase in albumin reabsorption, no concurrent increase in inflammatory or profibrotic markers were observed. Exposure to LDL increased monocyte chemoattractant protein-1 (MCP-1) (P < 0.05) and transforming growth factor-beta1 (TGF-beta1) (P < 0.05) production, which were reversed in the presence of pioglitazone. LDL induced increases in MCP-1 and TGF-beta1 were independent of nuclear factor-kappaB (NF-kappaB) transcriptional activity. In contrast, tubular exposure to albumin increased tubular protein uptake, in parallel with an increase in MCP-1 (P= 0.05), TGF-beta1 (P < 0.02) and NF-kappaB transcriptional activity (P < 0.05), which were unaffected by concurrent exposure to pioglitazone.. These findings suggest that dyslipidemia potentiates renal pathology through mechanisms that may be modified by PPARgamma activation independent of NF-kappaB transcriptional activity. In contrast, tubular exposure to protein induces renal damage through NF-kappaB-dependent mechanisms that are unaffected by PPARgamma activation.

Topics: Albumins; Animals; Biological Transport, Active; Cell Division; Cells, Cultured; Chemokine CCL2; Fibrosis; Genes, Reporter; Inflammation; Kidney Tubules; NF-kappa B; Opossums; Pioglitazone; PPAR gamma; Proteinuria; Thiazolidinediones; Transforming Growth Factor beta; Transforming Growth Factor beta1

Connective tissue growth factor (CTGF) is strongly upregulated in fibrotic disorders and has been hypothesized to play a role in the development and progression of diabetes complications. The aim of the present study was to investigate the possible association of plasma CTGF levels in type 1 diabetic patients with markers relevant to development of diabetes complications.. Plasma CTGF levels (full-length and NH2-terminal fragments) were determined in 62 well-characterized patients with type 1 diabetes and in 21 healthy control subjects. Correlations of these plasma CTGF levels with markers of glycemic control, platelet activation, endothelial activation, nephropathy, and retinopathy were investigated.. -Elevated plasma NH2-terminal fragment of CTGF (CTGF-N) levels were detected in a subpopulation of type 1 diabetic patients and were associated with diabetic nephropathy. Stepwise regression analysis revealed contribution of albuminuria, creatinine clearance, and duration of diabetes as predictors of plasma CTGF-N level. Elevation of plasma CTGF-N levels in patients with retinopathy was probably due to renal comorbidity.. Plasma CTGF-N levels are elevated in type 1 diabetic patients with nephropathy and appear to be correlated with proteinuria and creatinine clearance. Further studies will be needed to determine the relevance of plasma CTGF as a clinical marker and/or pathogenic factor in diabetic nephropathy.

Topics: Adult; Biomarkers; Connective Tissue Growth Factor; Creatinine; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Female; Humans; Immediate-Early Proteins; Intercellular Signaling Peptides and Proteins; Male; Middle Aged; Proteinuria; Reference Values; Regression Analysis; Transforming Growth Factor beta

The molecular events associated with acute and chronic exposure of mesangial cells (MC) to hyperglycemia were evaluated. We found that, unlike high glucose (HG) and Amadori adducts, advanced glycation end products (AGE) and transforming growth factor-beta (TGF-beta) induced p21waf expression and accumulation of MC in G0/G1. TGF-beta1 blockade inhibited AGE-mediated collagen production but only partially affected AGE-induced p21waf expression and cell-cycle events, indicating that AGE by binding to AGE receptor (RAGE) per se could control MC growth. Moreover, AGE and TGF-beta treatment led to the activation of the signal transduction and activators of transcription (STAT)5 and the formation of a STAT5/p21SIE2 complex. The role of STAT5 in AGE- and TGF-beta-mediated p21waf expression and growth arrest, but not collagen production, was confirmed by the expression of the dominant negative STAT5 (DeltaSTAT5) or the constitutively activated STAT5 (1*6-STAT5) constructs. Finally, in p21waf-/- fibroblasts both AGE and TGF-beta failed to inhibit cell-cycle progression. A potential in vivo role of these mechanisms was sustained by the increasing immunoreactivity for the activated STAT5 and p21(waf) in kidney biopsies from early to advanced stage of diabetic nephropathy. Our data indicate that AGE- and TGF-beta-mediated signals, by converging on STAT5 activation and p21waf expression, may regulate MC growth.

Topics: Albuminuria; Cell Cycle; Cell Cycle Proteins; Cell Division; Cells, Cultured; Collagen; Cyclin-Dependent Kinase Inhibitor p21; Diabetic Nephropathies; DNA Replication; DNA-Binding Proteins; Fibroblasts; Glomerular Mesangium; Glycation End Products, Advanced; Humans; Hypertrophy; Milk Proteins; Nephrotic Syndrome; Proteinuria; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Signal Transduction; STAT5 Transcription Factor; Trans-Activators; Transcription, Genetic; Transfection; Transforming Growth Factor beta; Transforming Growth Factor beta1

Spontaneously hypertensive stroke-prone rats (SHRSP) develop hypertension and systemic inflammation, with subsequent brain and renal disorders and early death. We tested the hypothesis that valsartan, an angiotensin II type 1 (AT1) receptor antagonist, exerts protective effects in SHRSP through its anti-inflammatory properties, even in the absence of a blood pressure-lowering effect. SHRSP fed a high-salt diet were treated with vehicle or valsartan (1-10 mg/kg/day). The vehicle-treated rats developed hypertension, proteinuria, progressive kidney disease, and, 40 +/- 5 days from the beginning of the treatment, brain damage as visualized by magnetic resonance imaging. Rats treated with 1 mg/kg/day valsartan developed brain damage after 61 +/- 3 days (p <0.01 versus vehicle-treated rats). No damage showed after 100 days in 80% of the rats treated with 10 mg/kg/day. Valsartan treatment preserved renal structure, by preventing the infiltration of inflammatory cells, and lowered renal expression of monocyte chemoattractant protein-1, transforming growth factor-beta1, and interleukin-1beta, compared with vehicle-treated SHRSP. Urinary excretion of acute-phase proteins increased in the latter but remained negligible in the drug-treated animals. Furthermore, valsartan exerted protective effects also when given after established proteinuria. In SHRSP, blockade of AT1 receptor with valsartan prevents the development of proteinuria, delays the appearance of brain damage, preserves renal structure, and increases survival under stressful conditions. Valsartan exerts its beneficial effects independently of any blood pressure fall and by means of broad anti-inflammatory actions both at local and at systemic levels. These observations indicate that the administration of AT1 receptor antagonists may be useful in pathological situations in which an anti-inflammatory effect is required.

Topics: Angiotensin II Type 1 Receptor Blockers; Animals; Anti-Inflammatory Agents; Blood Pressure; Body Weight; Brain; Chemokine CCL2; Immunohistochemistry; Interleukin-1; Kidney; Magnetic Resonance Imaging; Male; Proteinuria; Rats; Rats, Inbred SHR; RNA, Messenger; Stroke; Survival Analysis; Tetrazoles; Transforming Growth Factor beta; Valine; Valsartan

Effects of the blockade of renin-angiotensin system (RAS), by angiotensin-converting enzyme inhibitor (ACEi), type 1 angiotensin II receptor blocker (ARB), or a combination of both, were evaluated in Adriamycin (ADR)-induced glomerulopathy.. Male Sprague-Dawley rats (180-250 g) were induced of glomerulopathy by treatment with ADR (2 mg/kg, i.v.). Six weeks later, they were treated with cilazapril (1 mg/kg/day) and/or losartan (10 mg/kg/day) for an additional 6 weeks.. The urinary excretion of protein progressively increased following the treatment with ADR, which was prevented by ACEi, ARB, and a combination of both. Similarly, the glomerulopathy assessed by glomerulosclerosis index was also ameliorated by ACEi or ARB. However, combined therapy of both ACEi and ARB was without an additional effect (Control 1.4 +/- 0.4%, ADR 10.7 +/- 2.7%**, ACEi 0.8 +/- 0.4%, ARB 2.6 +/- 1.0%, ACEi+ARB 1.7 +/- 1.5%, ** p < 0.01 vs. Control). The expression of transforming growth factor-beta(1) was increased following the treatment with ADR (1.4 +/- 0.07-fold, p < 0.05 vs. Control), however, the degree of which was similarly blunted by either ACEi, ARB, or the combination of both. The expression of type 1 angiotensin II receptor mRNA increased following the treatment with ADR, the degree of which was further upregulated by ACEi and decreased by ARB to the control level (ADR 1.3 +/- 0.06-fold*, ACEi 1.8 +/- 0.05-fold***, ARB 1.0 +/- 0.04-fold, * p < 0.05 and *** p < 0.001 vs. Control). The combined therapy of ACEi and ARB still showed an upregulation of type 1 angiotensin II receptor mRNA, however, of which degree was mitigated compared with that induced by ACEi alone (ACEi+ARB 1.5 +/- 0.04-fold, ** p < 0.01 vs. Control). On the contrary, the expression of type 2 angiotensin II receptor mRNA was downregulated following the treatment with ADR, which was similarly restored to the control level by ACEi, ARB, and a combination of both (ADR 0.5 +/- 0.08-fold**, ACEi 1.0 +/- 0.06-fold, ARB 1.0 +/- 0.05-fold, ACEi+ARB 1.0 +/- 0.05-fold, ** p < 0.01 vs. Control).. It is suggested that combined therapy of ACEi and ARB with relatively high or maximal doses of each drug has no additive or synergistic benefits on the progression of ADR-induced glomerulopathy. Effects of RAS blockade may in part be related to differential regulation of type 1 and type 2 angiotensin II receptors.

Topics: Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Pressure; Cilazapril; Doxorubicin; Drug Interactions; Drug Synergism; Gene Expression Regulation; Glomerulosclerosis, Focal Segmental; Losartan; Male; Nephrosis, Lipoid; Proteinuria; Rats; Rats, Sprague-Dawley; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Renin-Angiotensin System; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1

We previously showed that mice lacking galectin-3/AGE-receptor 3 develop accelerated diabetic glomerulopathy. To further investigate the role of galectin-3/AGE-receptor function in the pathogenesis of diabetic renal disease, galectin-3 knockout (KO) and coeval wild-type (WT) mice were injected for 3 months with 30 microg/day of N(epsilon)-carboxymethyllysine (CML)-modified or unmodified mouse serum albumin (MSA). Despite receiving equal doses of CML, KO had higher circulating and renal AGE levels and showed more marked renal functional and structural changes than WT mice, with significantly higher proteinuria, albuminuria, glomerular, and mesangial area and glomerular sclerosis index. Renal 4-hydroxy-2-nonenal content and NFkappaB activation were also more pronounced in KO-CML vs. WT-CML. Kidney mRNA levels of fibronectin, laminin, collagen IV, and TGF-beta were up-regulated, whereas those of matrix metalloproteinase-2 and -14 were down-regulated, again more markedly in KO-CML than WT-CML mice. Basal and CML-induced RAGE and 80K-H mRNA levels were higher in KO vs. WT mice. MSA injection did not produce any significant effect in both genotypes. The association of galectin-3 ablation with enhanced susceptibility to AGE-induced renal disease, increased AGE levels and signaling, and altered AGE-receptor pattern indicates that galectin-3 is operating in vivo as an AGE receptor to afford protection toward AGE-dependent tissue injury.

Topics: Aldehydes; Animals; Cell Death; Cell Proliferation; Extracellular Matrix Proteins; Galectin 3; Glycation End Products, Advanced; Kidney; Kidney Cortex; Kidney Diseases; Kidney Glomerulus; Kinetics; Lysine; Matrix Metalloproteinases; Mice; Mice, Inbred C57BL; Mice, Knockout; NF-kappa B; Proteinuria; Receptor for Advanced Glycation End Products; Receptors, Immunologic; RNA, Messenger; Transforming Growth Factor beta

Combination therapy with angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) is used to improve renal outcome achieved by monotherapy in diabetic patients. In addition, interference with the renin-angiotensin system (RAS) reduced expression and excretion of transforming growth factor beta 1 (TGF-beta 1) in diabetic nephropathy. The aim of this study was to investigate the effects of interrupting the RAS by ACE inhibitor (ACE-I) or ARB monotherapy or by combination therapy on proteinuria, kidney hypertrophy and plasma TGF-beta 1 in diabetic rats.. Forty-one male Wistar rats were allocated to five groups: 1 = control rats, 2 = diabetic rats (streptozotocin [STZ] 55 mg/kg), 3 = diabetic rats as above receiving enalapril (20 mg/kg/day), 4 = diabetic rats receiving losartan (80 mg/kg/day), 5 = diabetic rats receiving both losartan and enalapril. The study lasted 60 days.. Urinary protein excretion, kidney weight, serum ACE activity and plasma TGF-beta1 increased significantly in untreated diabetic rats compared with controls. Administration of losartan, enalapril, or both for 60 days prevented these changes. Furthermore, combined therapy for 30 days normalised urinary protein excretion, while monotherapy did not. Losartan inhibited serum ACE activity both in vivo and in vitro. Plasma TGF-beta 1 levels were positively correlated with blood glucose levels (r=0.4059) and with urinary protein excretion (r=0.3558).. Combination therapy with losartan and enalapril was more effective than monotherapy with either drug in achieving an early antiproteinuric response. Long-term treatment with losartan was as effective as the combined treatment, possibly due to a dual inhibitory effect on the RAS. The antiproteinuric effect may be related, in part, to reduced TGF-beta 1.

Topics: Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Animals; Diabetes Mellitus, Experimental; Drug Synergism; Enalapril; Hypertrophy; Kidney; Losartan; Male; Proteinuria; Rats; Rats, Wistar; Renin-Angiotensin System; Transforming Growth Factor beta; Transforming Growth Factor beta1

Men with chronic renal disease progress more rapidly to renal failure than do women. Tranforming growth factor-beta (TGF-beta) plays a central role in promoting progressive renal injury, in part due to transcriptional effects mediated by cooperation between Smad proteins and the transcription factor Sp1. Estrogen negatively regulates Sp1 activity and reverses the stimulatory effects of TGF-beta on type IV collagen synthesis and cellular apoptosis in cultured mesangial cells. We hypothesized that the ability of estradiol to reverse the effects of TGF-beta underlies gender dimorphism in the progression of chronic renal disease.. We studied Alb/TGF-beta transgenic mice, which overexpress TGF-beta1 and develop proteinuria and progressive glomerulosclerosis. We implanted a sustained-release estradiol pellet or a placebo pellet into control and Alb/TGF-beta transgenic mice at 2 weeks of age. Animals were sacrificed at 5 weeks, at which time urine, blood, and renal tissue were obtained for study.. The sustained-release estradiol pellet achieved a physiologic concentration of estradiol. TGF-beta levels were higher in estradiol-treated mice compared to placebo-treated mice. Proteinuria was reduced in estradiol-treated Alb/TGF-beta mice compared to placebo-treated transgenic mice. Mesangial expansion and closure of capillary loops with enhanced glomerular deposition of type I collagen, type IV collagen, and tissue inhibitor of metalloproteinase (TIMP-2) was observed in glomeruli of placebo-treated transgenic mice. Estrogen therapy reversed these abnormalities.. Administration of estradiol to Alb/TGF-beta transgenic mice, which overexpress TGF-beta, ameliorated progressive renal injury. The ability of estradiol to reverse the pro-fibrotic effects of TGF-beta, both in vitro and in vivo, may underlie the sexual dimorphism in renal disease progression observed in humans.

Topics: Animals; Apoptosis; Collagen Type I; Delayed-Action Preparations; Drug Implants; Estradiol; Glomerulosclerosis, Focal Segmental; In Vitro Techniques; Kidney Glomerulus; Male; Mice; Mice, Inbred C57BL; Mice, Inbred CBA; Mice, Transgenic; Proteinuria; Transforming Growth Factor beta; Transforming Growth Factor beta1

Female sex hormones may influence the progression of renal diseases. We therefore evaluated the effects of estradiol on the development of glomerulosclerosis in a remnant kidney model.. Ovariectomized or intact female Wistar rats underwent 5/6 nephrectomy. Ovariectomized animals were treated with vehicle, 17beta-estradiol alone or in combination with progesterone, intact rats received vehicle only. Twenty-four weeks after renal ablation, histological as well as molecular analysis were performed.. Vehicle-treated ovariectomized animals developed severe proteinuria and glomerulosclerosis as compared with vehicle-treated intact rats. In addition, renal mRNA levels of platelet-derived growth factor-A chain (PDGF-A) were increased. Estradiol replacement reduced proteinuria, which was paralleled by a diminished glomerular injury and reduced transforming growth factor-beta1 (TGF-beta1) and PDGF-A mRNA expression. In animals that received combined hormone treatment there were no significant differences in proteinuria, creatinine clearance, renal histopathology and growth factor mRNA levels compared with those measured in vehicle-treated ovariectomized rats. Serum cholesterol and triglyceride levels were comparable between all groups during the whole follow-up period.. The data suggest that estrogens protect against the development of glomerulosclerosis in the rat remnant kidney model.

Topics: Animals; Body Weight; Estradiol; Female; Gene Expression Regulation; Kidney; Nephrectomy; Organ Size; Ovariectomy; Platelet-Derived Growth Factor; Proteinuria; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; RNA; RNA, Messenger; Transcription, Genetic; Transforming Growth Factor beta; Transforming Growth Factor beta1; Uterus

Alport syndrome (AS) is a common hereditary cause of end-stage renal failure in adolescence due to defects in type IV collagen genes. Molecular genetics allows early diagnosis, however, no preventive strategy can be offered. Using the COL4A3 -/- mouse, an animal model for human AS, we evaluated therapy with ramipril in mice.. One hundred and twenty-two Alport-mice were treated with 10 mg/kg/day ramipril added to drinking water. Proteinuria, serum-urea and lifespan were monitored. Renal matrix was characterized by immunohistochemistry, light- and electron microscopy, and Western blot.. Untreated COL4A3 -/- mice died from renal failure after 71 +/- 6 days. Early therapy starting at four weeks of age and continuing to death delayed onset and reduced the extent of proteinuria. Uremia was postponed by three weeks in treated animals. Lifespan increased by more than 100% to 150 +/- 21 days (P < 0.01). In parallel, decreased deposition of extracellular matrix and lessened interstitial fibrosis as well as reduced amounts of renal transforming growth factor-beta1 (TGF-beta1) could be demonstrated. Late therapy starting at seven weeks decreased proteinuria, however, lifespan did not increase significantly.. The results indicate an antiproteinuric and antifibrotic nephroprotective effect of ramipril in COL4A3 -/- mice is mediated by down-regulation of TGF-beta1. This effect in mice is enhanced by initiation of therapy during pre-symptomatic disease. The data in COL4A3 -/- mice as an animal-model for Alport syndrome suggest that ramipril might as well delay renal failure in humans with AS. Early diagnosis and preemptive treatment also may be crucial in humans.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Autoantigens; Basement Membrane; Collagen Type IV; Disease Models, Animal; Extracellular Matrix; Fibrosis; Kidney; Kidney Glomerulus; Longevity; Mice; Mice, Knockout; Nephritis, Hereditary; Proteinuria; Ramipril; Renal Insufficiency; Transforming Growth Factor beta; Transforming Growth Factor beta1; Uremia

Severe proteinuria not only indicates the presence of progressive glomerular disease, but also causes tubular epithelial cells to produce inflammatory mediators leading to tubulointerstitial (TI) injury. We investigated the role of nuclear factor-kappaB (NF-kappaB) in tubular epithelial cells in the development of proteinuria-induced TI injury.. To specifically inhibit NF-kappaB activation, a recombinant adenovirus vector expressing a truncated form of IkappaBalpha (AdexIkappaBDeltaN) was injected into renal arteries of protein-overloaded rats, a model of TI injury characterized by infiltration of mononuclear cells and fibrosis.. Activation of NF-kappaB in the renal cortex, observed in protein-overloaded rats treated with a control vector, recombinant lacZ adenovirus, was prevented in AdexIkappaBDeltaN-injected rats. Microscopic examination revealed AdexIkappaBDeltaN treatment to markedly attenuate proteinuria-induced TI injury. Increased immunostaining of vascular cell adhesion molecule-1, transforming growth factor-beta, and fibronectin in TI lesions also was suppressed by AdexIkappaBDeltaN injection.. These findings provide evidence of the critical role of NF-kappaB activation in TI injury and suggest the therapeutic potential of adenovirus-mediated IkappaBDeltaN gene transfer into the kidney as a means of interrupting the process of TI damage.

Topics: Animals; beta-Galactosidase; Female; Fibronectins; Gene Expression; Gene Transfer Techniques; I-kappa B Proteins; Kidney Cortex; Kidney Tubules; NF-kappa B; Peptide Fragments; Proteinuria; Rats; Time Factors; Transforming Growth Factor beta; Vascular Cell Adhesion Molecule-1

Renin-angiotensin system (RAS) overactivity has been implied in progressive renal function loss. We investigated whether changes in the renal expression of RAS components are specifically associated with the proteinuric kidney. Unilateral adriamycin-induced proteinuria was obtained by clamping the left renal artery before injection of adriamycin. In control animals, both left and right renal arteries were clamped. Twelve weeks later, mRNA expression of RAS components was determined in both kidneys. In the affected and non-affected kidney of the unilateral proteinuric rat, we demonstrate up-regulation of angiotensin- converting enzyme (ACE) mRNA (213%+22 and 188%+24 of controls, respectively), up-regulation of transforming growth factor beta (TGF-beta) mRNA (956%+229 and 418%+56) and down-regulation of angiotensin type 2 receptor (AT2-R) mRNA (24%+5 and 20%+5). The expression of angiotensin type 1 receptor (AT1-R) mRNA and inositol 1,4,5- trisphosphate receptor type I (IP3R-I) mRNA were unchanged. In conclusion, renal expression of ACE, AT2-R, and AT1-R mRNA is not mediated by protein leakage. Local intrarenal protein leakage did influence renal TGF-beta mRNA expression.

Topics: Animals; Antineoplastic Agents; Blood Pressure; Calcium Channels; Cholesterol; Doxorubicin; Gene Expression; Inositol 1,4,5-Trisphosphate Receptors; Kidney; Nephrotic Syndrome; Peptidyl-Dipeptidase A; Proteinuria; Rats; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Receptors, Angiotensin; Receptors, Cytoplasmic and Nuclear; Renin-Angiotensin System; RNA, Messenger; Transforming Growth Factor beta

NO mediates antifibrotic actions of L-arginine supplementation following induction of anti-thy1 glomerulonephritis.. L-Arginine plays a complex role in renal matrix expansion, involving endogenous metabolism into nitric oxide (NO), polyamines, L-proline and agmatine. Supplementing dietary L-arginine intake has been shown to limit transforming growth factor (TGF)-beta 1 overproduction and matrix accumulation in rats with induced anti-thy1 glomerulonephritis (GN). The present study tests the hypothesis that this beneficial effect on in vivo TGF-beta overexpression is mediated via the generation of NO.. One day after induction of anti-thy1 GN, male Wistar rats fed a normal protein diet were assigned to the following groups: (1) normal controls; (2) GN; (3) GN-Arg (plus 500 mg L-arginine/day); (4) GN-Arg-NAME [plus 500 mg L-arginine/day and 75 mg/L of the NO synthase inhibitor nitro-L-arginine-methyl ester (L-NAME) in the drinking water]; and (5) GN-Molsi (10 mg/day of the NO donor molsidomine). In protocol 1, treatment lasted until day 7, and in protocol 2, until day 12 after disease induction, respectively. Analysis included systolic blood pressure, a glomerular histologic matrix score, and the glomerular mRNA and protein expression of the key fibrogen TGF-beta1, the matrix protein fibronectin, and the protease inhibitor plasminogen activator inhibitor type 1 (PAI-1).. Blood pressure was normal in untreated anti-thy1 animals and not significantly affected by any of the treatments. Compared to untreated nephritic rats, administration of both L-arginine and molsidomine reduced glomerular TGF-beta 1 overexpression significantly and to a similar degree in both protocols, while the beneficial effect of L-arginine was abolished by concomitant NO synthesis inhibition. Glomerular matrix accumulation, fibronectin and PAI-1 mRNA and protein expression closely followed the expression of TGF-beta 1.. The present study shows that L-arginine's antifibrotic action in normotensive anti-thy1 GN is mainly mediated by endogenous production of NO. The data suggest that NO limits in vivo TGF-beta overexpression in a pressure-independent manner and that NO donors may be of benefit in the treatment of human fibrotic renal disease.

Topics: Animals; Arginine; Blood Pressure; Body Weight; Enzyme Inhibitors; Fibronectins; Fibrosis; Gene Expression; Glomerulonephritis; Isoantibodies; Male; Molsidomine; NG-Nitroarginine Methyl Ester; Nitrates; Nitric Oxide; Nitric Oxide Donors; Nitrites; Plasminogen Activator Inhibitor 1; Proteinuria; Rats; Rats, Wistar; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1

Leptin may contribute to renal pathology in some situations by stimulating transforming growth factor-beta1 (TGF-beta1) synthesis. The soluble leptin receptor (sOb-R) is a transport protein contributing to binding and activation of circulating leptin. We investigated the interaction between serum and urinary leptin, TGF-beta1, and serum sOb-R levels in 38 patients with minimal change nephrotic syndrome (MCNS) aged between 6 and 12 years and 10 age- and sex-matched healthy controls (group III). Patients were divided into two groups: group I, proteinuria exceeding >40 mg/m(2) per hour and group II, patients in remission. Serum leptin levels in group I were significantly lower than those in group II and group III ( P=0.011, P=0.007, respectively). There was a negative correlation between serum leptin levels and proteinuria ( r=-0.52, P=0.02) as well as between serum leptin and sOb-R levels ( r=-0.82, P=0.000) in group I. Urine leptin and sOb-R levels in group I were significantly higher than in group II ( P=0.0021, P=0.001, respectively) and group III ( P=0.07, P=0.009, respectively). Serum TGF-beta1 levels in healthy controls (406+/-424 pg/ml) were significantly lower than those in groups I and II ( P=0.004, P=0.000, respectively). However, no significant correlation was found between the serum TGF-beta1 and leptin levels in MCNS patients. In conclusion, low serum leptin, high serum TGF-beta1 and sOb-R levels, and elevated urine leptin concentrations were observed at the onset of MCNS. Since long-term proteinuria and leptinuria might be associated with the progression of renal damage, future in vivo and in vitro studies are needed to explain the interaction between these parameters in different types of nephrotic syndrome.

Topics: Body Mass Index; Child, Preschool; Female; Humans; Infant; Leptin; Male; Nephrosis, Lipoid; Proteinuria; Receptors, Cell Surface; Receptors, Leptin; Solubility; Transforming Growth Factor beta; Transforming Growth Factor beta1

The overexpression of transforming growth factor (TGF)-beta and Smad-mediated intracellular TGF-beta signaling in the kidney underlies the development of renal scarring from pathological matrix accumulation. However, changes in the Smad proteins during the progression of kidney disease are unclear. In this study, we investigated the regulation of Smad proteins in the glomeruli of rats with anti-thymocyte serum nephritis. We found that Smad2 protein decreased markedly in nephritic glomeruli, whereas no significant changes were observed in the levels of Smad3 and Smad4 proteins. In contrast, the level of Smad2 mRNA in nephritic glomeruli did not differ significantly from that in control glomeruli. Based on recent reports of the ubiquitin-mediated degradation of Smad2, we investigated the degradation and ubiquitination activity directed against Smad2 in glomerular extracts. Both the degradation and ubiquitination of Smad2 were markedly increased in glomerular extracts from rats with nephritis. We also found that Smurf2, a ubiquitin ligase for Smad2, was increased in the nephritic glomerular extracts. These data suggest that the decrease in Smad2 resulted from enhanced ubiquitin-dependent degradation of Smad2 mediated by Smurf2, and is involved in the regulation of Smad2-mediated TGF-beta signaling in nephritic glomeruli.

Topics: Animals; Antilymphocyte Serum; DNA-Binding Proteins; Glutathione Transferase; In Vitro Techniques; Kidney Glomerulus; Ligases; Male; Nephritis; Phosphoproteins; Proteinuria; Rats; Rats, Wistar; Recombinant Fusion Proteins; Sheep; Smad2 Protein; Smad3 Protein; Smad4 Protein; Trans-Activators; Transforming Growth Factor beta; Transforming Growth Factor beta1; Ubiquitin; Ubiquitin-Protein Ligases

Children with nephrotic syndrome are always associated with retardation of growth. Growth hormone (GH) administration to these children can stimulate their growth, but it plays an important role in glomerulosclerosis. Thus these children would take a risk to use it to improve their growth. This study was designed to investigate the effect of GH on the kidney of rats with adriamycin-induced nephropathy (AN) and its mechanism, and to observe the renoprotective effect of angiotensin II (AngII) receptor antagonist, irbesartan, in GH-treated AN rats.. Rats were divided into the following groups: normal control rats, AN rats, GH-treated AN rats and GH plus irbesartan-treated AN rats. There were 8 developing male SD rats (120-130 g) in each group. Urinary protein was measured at weeks 3, 6 and 9. Blood pressure, serum creatinine, BUN, albumin, cholesterol, triglyceride, as well as ACE activity and AngII concentration of the kidney were detected at the end of the study. Renal pathological changes were evaluated also. Immunohistochemistry was used to examine the protein expressions of TGF beta(1), collagen IV and fibronectin in glomeruli.. Glomerular sclerosis score of GH-treated AN rats (49.4 +/- 9.8) was significantly higher than that of AN rats (12.8 +/- 5.5, P < 0.01), and this score of GH-treated AN rats plus irbesartan (26.2 +/- 7.5) was significantly lower than the score of GH-treated AN rats (P < 0.01). The changes of urinary protein, hyperlipidemia and hypoalbuminemia in rats of each group consisted with the degree of glomerular injury in rats of each group. There was azotemia in GH-treated AN rats, but rats in the other groups did not have azotemia. ACE activity of kidney was significantly (P < 0.01) increased in GH-treated AN rats [(28.1 +/- 4.1) U/mg pro] and GH-treated AN rats plus irbesartan [(27.6 +/- 3.4) U/mg pro] compared with that in AN rats [(14.6 +/- 4.4) U/mg pro]. AngII concentrations in the kidney of GH-treated AN rats [(17.8 +/- 3.3) pg/mg pro] and GH-treated AN rats plus irbesartan [(27.3 +/- 5.1) pg/mg pro] were significantly higher than that in AN rats [(8.3 +/- 1.9) pg/mg pro] (P < 0.01). The protein expressions of TGF-beta(1), collagen IV and fibronectin in GH-treated AN rats were the most distinct in all groups. These expressions were significantly (P < 0.05) reduced in GH-treated AN rats plus irbesartan.. GH is able to exacerbate adriamycin-induced nephropathy in rats, which was partly through activating renal tissue RAS and initiating the function of the AngII-TGF beta(1)-ECM axis. Angiotensin II receptor antagonist, irbesartan, has some renal protective effects on AN rats treated with GH.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Animals; Antibiotics, Antineoplastic; Biphenyl Compounds; Blood Urea Nitrogen; Collagen Type IV; Creatinine; Disease Models, Animal; Doxorubicin; Fibronectins; Growth Hormone; Immunohistochemistry; Irbesartan; Kidney Diseases; Kidney Glomerulus; Male; Peptidyl-Dipeptidase A; Proteinuria; Random Allocation; Rats; Rats, Sprague-Dawley; Serum Albumin; Tetrazoles; Transforming Growth Factor beta; Triglycerides

Serum transforming growth factor-beta (TGF-beta1) production was estimated for 10 patients with essential hypertension, 12 patients with glomerulonephritis (5 hypertensive and 7 normotensive) and 10 healthy controls. The glomerulonephritis group received angiotensin-converting enzyme inhibitor captopril 25-75 mg/day for 4 weeks. Blood urea, serum creatinine, 24-hour urinary protein and serum TGF-beta1 were then re-estimated. Urea and creatinine were significantly higher in the hypertension and glomerulonephritis groups than in the controls and also higher in the glomerulonephritis group than the hypertension group. TGF-beta1 was significantly higher in the glomerulonephritis groups than in the control and hypertension groups. TGF-beta1 and 24-hour urinary protein were significantly reduced in the glomerulonephritis group.

Topics: Adult; Angiotensin-Converting Enzyme Inhibitors; Blood Urea Nitrogen; Captopril; Case-Control Studies; Chronic Disease; Creatinine; Female; Glomerulonephritis; Humans; Hypertension; Immunoassay; Male; Middle Aged; Proteinuria; Transforming Growth Factor beta; Transforming Growth Factor beta1; Treatment Outcome

To study the protective effects of Tripterine on experimental lupus nephritis glomerulosclerosis.. Different doses of Tripterine were injected peritoneally to BW F1 mice at different stages. 24-hour urine protein excretion, serum anti-dsDNA antibodies, renal pathology and RT-nested PCR were analyzed to study the preventive effects of Tripterine on LN glomerulosclerosis and its mechanisms.. (1) Tripterine suppressed the development of proteinuria, decreased the level of serum anti-dsDNA antibodies, reduced the expressions of collagen type IV, fibronectin, TIMP-1, TIMP-2, TGF-beta(1) and improved the expressions of MMP-1, -2 in the murine kidney. (2) The use of Tripterine before occurrence of proteinuria had more obvious protective effects than its use after the occurrence of proteinuria. (3) No significant difference was found between the 3 mg/kg/week Tripterine-treated-group and the 6 mg/kg/week Tripterine-treated-group. (4) No obvious change was observed in the expression of MMP-3.. Tripterine has a definite protective effect on glomerulosclerosis of the lupus murine model. The decrease of renal collagen type IV and fibronectin is probably due to its suppressive effect on the expressions of local TGF-beta(1) and TIMP-1, -2, and its improvement effect on the local expressions of MMP-1, -2. Tripterine may have no obvious influence on MMP-3 in this model.

Topics: Animals; Antibodies, Antinuclear; Female; Glomerulosclerosis, Focal Segmental; Immunohistochemistry; Kidney; Lupus Nephritis; Mice; Pentacyclic Triterpenes; Proteinuria; Reverse Transcriptase Polymerase Chain Reaction; Time Factors; Transforming Growth Factor beta; Transforming Growth Factor beta1; Triterpenes

This study examined the role of transforming growth factor-beta (TGF-beta) in the development of hypertension and renal disease in 9-wk-old male Dahl salt-sensitive (Dahl S) rats fed an 8% NaCl diet for 3 wk. The rats received an intraperitoneal injection of a control or an anti-TGF-beta antibody (anti-TGF-beta Ab) every other day for 2 wk. Mean arterial pressure was significantly lower in Dahl S rats treated with anti-TGF-beta Ab (177 +/- 3 mmHg, n = 12) than in control rats (190 +/- 4 mmHg, n = 17). Anti-TGF-beta Ab therapy also reduced proteinuria from 226 +/- 20 to 154 +/- 16 mg/day. Renal blood flow, cortical blood flow, and creatinine clearance were not significantly different in control and treated rats; however, medullary blood flow was threefold higher in the treated rats than in the controls. Despite the reduction in proteinuria, the degree of glomerulosclerosis and renal hypertrophy was similar in control and anti-TGF-beta Ab-treated rats. Renal levels of TGF-beta1 and -beta2, alpha-actin, type III collagen, and fibronectin mRNA decreased in rats treated with anti-TGF-beta Ab. To examine whether an earlier intervention with anti-TGF-beta Ab would confer additional renoprotection, these studies were repeated in a group of 6-wk-old Dahl S rats. Anti-TGF-beta Ab therapy significantly reduced blood pressure, proteinuria, and the degree of glomerulosclerosis and renal medullary fibrosis in this group of rats. The results indicate that anti-TGF-beta Ab therapy reduces blood pressure, proteinuria, and the renal injury associated with hypertension.

Topics: Anesthesia; Animals; Antibodies, Monoclonal; Blood Pressure; Collagen Type III; Fibronectins; Glomerulosclerosis, Focal Segmental; Hypertension, Renal; Kidney Glomerulus; Male; Proteinuria; Rats; Rats, Inbred Dahl; Renal Circulation; Sodium Chloride, Dietary; Transforming Growth Factor beta; Transforming Growth Factor beta1; Transforming Growth Factor beta2

Increases in transforming growth factor-beta (TGF-beta) expression and extracellular matrix accumulation are transient in acute self-limited mesangial proliferative glomerulonephritis induced by a single injection of anti-thymocyte serum (ATS), while these increases persist following repeated injections that produce chronic progressive sclerosing glomerulonephritis with tubulointerstitial lesions. However, little is known about the expression of TGF-beta receptors (TbetaRs) in cells involved in the proliferative and sclerosing renal lesions. A study of protein and mRNA expression for type I (TbetaRI), type II (TbetaRII), and type III (TbetaRIII) TbetaR in both forms of nephritis was therefore carried out by immunohistochemistry and in situ hybridization. Inhibition of cell proliferation and stimulation of matrix production by TGF-beta1 were assessed in isolated glomeruli using [(3)H]thymidine incorporation and [(3)H]proline metabolic labelling, respectively. In acute self-limited nephritis, expression of TbetaRI, TbetaRII, and TbetaRIII increased in the glomerular and Bowman's capsular epithelial cells comprising the glomerular tuft adhesions to Bowman's capsules. However, TbetaRII expression was not prominent in proliferating mesangial cells. Glomeruli isolated from rats with acute self-limited nephritis at day 7, when mesangial cell proliferation was maximal, were partially resistant to the mitoinhibitory effects of TGF-beta1. In contrast, expression of all three TbetaRs was elevated in glomerular and tubulointerstitial lesions in chronic progressive nephritis, and glomeruli isolated from rats with chronic progressive nephritis 7 days after the second ATS injection were sensitive to TGF-beta1. These data suggest that distinct cellular responses to TGF-beta1 resulting from differential expression of TbetaR underlie the difference between acute self-limited mesangial proliferative and chronic progressive sclerosing ATS nephritis in the development of proliferative and sclerotic renal lesions.

Topics: Acute Disease; Animals; Cell Division; Chronic Disease; Culture Techniques; Disease Progression; Extracellular Matrix; Extracellular Matrix Proteins; Gene Expression; Glomerulonephritis, Membranoproliferative; Immune Sera; Kidney; Kidney Glomerulus; Male; Proteinuria; Rats; Rats, Wistar; Receptors, Transforming Growth Factor beta; RNA, Messenger; Transforming Growth Factor beta

It has been previously shown that 2-hydroxyestradiol (2-OHE) attenuates the development of renal disease in genetic nephropathy associated with obesity and the metabolic syndrome. The purpose of this study was to test the hypothesis that 2-OHE, irrespective of its effects on metabolic status and/or obesity, exerts direct renoprotective effects in vivo. First, the effects of increasing doses of 2-OHE on mesangial cell growth, proliferation, and collagen synthesis in isolated rat glomerular mesangial cells were evaluated in vitro. Second, the effects of 12-wk administration of 2-OHE (10 micro g/h per kg) on renal function and structure in chronic puromycin aminonucleoside (PAN)-induced nephropathy in rats were evaluated in vivo. 2-OHE concentration-dependently (0.001 to 1 micro mol/L; P < 0.001) inhibited serum (2.5%)-induced cell growth ((3)H-thymidine incorporation), collagen synthesis ((3)H-proline incorporation), and cell proliferation (cell number). Importantly, the inhibitory effects of 2-OHE (0.1 micro mol/L) were not blocked by ICI182780 (50 micro mol/L), an estrogen receptor antagonist. In vivo, chronic administration of PAN (75 mg/kg + 5 x 20 mg/kg) over 12 wk induced severe chronic renal disease. Chronic treatment with 2-OHE significantly (P < 0.05) attenuated PAN-induced decrease in glomerular filtration, reduced proteinuria, and the elevated BP, and it had no effect on PAN-induced increase in plasma cholesterol and triglycerides levels. 2-OHE had no effects on plasma testosterone levels in male nephropathic animals. Immunohistochemical staining for collagen IV and proliferating cell nuclear antigen (PCNA) in glomeruli and transforming growth factor-beta (TGF-beta) in renal tubular cells were significantly higher in PAN nephropatic rats versus control animals with intact kidneys. PAN also markedly increased glomerular and interstitial macrophage infiltration (ED1(+) cells). 2-OHE had no effects on renal tubular cell TGF-beta, but it significantly reduced glomerular PCNA and collagen IV and glomerular and interstitial macrophage infiltration. In summary, this study provides the first evidence that 2-OHE exerts direct renoprotective effects in vivo. These effects are mediated by estrogen receptor-independent mechanisms and are due, at least in part, to the inhibition of some of the key proliferative mechanisms involved in glomerular remodeling and sclerosis.

Topics: Animals; Blood Pressure; Cell Division; Chronic Disease; Collagen Type IV; Cytoprotection; Estradiol; Glomerular Filtration Rate; Immunohistochemistry; Kidney Failure, Chronic; Kidney Tubules; Male; Proliferating Cell Nuclear Antigen; Proteinuria; Puromycin Aminonucleoside; Rats; Rats, Sprague-Dawley; Receptors, Estrogen; Reference Values; Transforming Growth Factor beta

Transforming growth factor-beta (TGF-beta) may be critical in the development of diabetic nephropathy (DN), and genetic predisposition is an important determinant of DN risk. We evaluated mRNA expression levels of TGF-beta system components in cultured skin fibroblasts (SFs) from type 1 diabetic patients with fast versus slow development of DN. A total of 125 long-standing type 1 diabetic patients were ranked by renal mesangial expansion score (MES) based on renal biopsy findings and diabetes duration. Patients in the highest quintile of MES who were also microalbuminuric or proteinuric (n = 16) were classified as "fast-track" for DN, while those in the lowest quintile who were also normoalbuminuric (n = 23) were classsified as "slow-track" for DN. Twenty-five normal subjects served as control subjects. SFs were cultured in medium with 25 mmol/l glucose for 36 h. SF mRNA expression levels for TGF-beta1, TGF-beta type II receptor (TGF-beta RII), thrombospondin-1, and latent TGF-beta binding protein-1 (LTBP-1) were measured by real-time RT-PCR. LTBP-1 mRNA expression was reduced in slow-track (0.99 +/- 0.38) versus fast-track patients (1.65 +/- 0.52, P = 0.001) and control subjects (1.41 +/- 0.7, P = 0.025). mRNA levels for TGF-beta1, TGF-beta RII, and thrombospondin-1 were similar in the three groups. Reduced LTBP-1 mRNA expression in SFs from slow-track patients may reflect genetically determined DN protection and suggests that LTBP-1 may be involved in the pathogenesis of DN through the regulation of TGF-beta activity.

Topics: Adult; Albuminuria; Carrier Proteins; Cells, Cultured; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Disease Progression; Female; Fibroblasts; Glomerular Mesangium; Humans; Intracellular Signaling Peptides and Proteins; Kidney; Latent TGF-beta Binding Proteins; Male; Middle Aged; Protein Serine-Threonine Kinases; Proteinuria; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Reference Values; RNA, Messenger; Skin; Thrombospondin 1; Time Factors; Transforming Growth Factor beta

Transforming growth factor-beta(1) (TGF-beta(1)) is the major fibrogenic growth factor implicated in the pathogenesis of renal scarring. Proteinuria is a poor prognostic feature for various types of glomerular disease and its toxic action may be related to the activation of tubular epithelial cells towards increased production of cytokines and chemoattractant peptides. In this work we studied the site of synthesis and expression profile of TGF-beta(1) in the renal tissue of patients with heavy proteinuria and examined the relation of this expression with the urinary excretion of TGF-beta(1).. Twenty-five patients with heavy proteinuria (8.4+/-3.0 g/24 h) were included in the study. All patients underwent a diagnostic kidney biopsy and were commenced on immunosuppressive therapy with corticosteroids and cyclosporin. The sites of synthesis and expression profile of TGF-beta(1) mRNA and protein in the kidney were examined by in situ hybridization and immunohistochemistry. Urinary and plasma TGF-beta(1) levels were determined by ELISA before the initiation of treatment and 6 months later and compared with those of normal subjects and of patients with IgA nephropathy and normal urinary protein excretion.. The site of synthesis and expression of TGF-beta(1) in the renal tissue of patients with heavy proteinuria was mainly localized within the cytoplasm of tubular epithelial cells. Interstitial expression was also present but glomerular TGF-beta(1) expression was found only in patients with mesangial proliferation. Urinary TGF-beta(1) excretion was significantly higher in nephrotic patients compared with normal subjects and with patients with IgA nephropathy and normal urinary protein excretion (783+/-280 vs 310+/-140 and 375+/-90 ng/24 h, respectively; P<0.01). In patients with remission of proteinuria after immunosuppressive therapy, urinary TGF-beta(1) excretion was significantly reduced (from 749+/-290 to 495+/-130 ng/24 h; P<0.01), while in patients with persistent nephrotic syndrome, it remained elevated.. The localization of TGF-beta(1) mRNA and protein within tubular epithelial cells, along with its increased urinary excretion in patients with nephrotic syndrome, suggest the activation of these cells by filtered protein towards increased TGF-beta(1) production.

Topics: Adult; Aged; Cyclosporine; Female; Glucocorticoids; Humans; Immunohistochemistry; Immunosuppressive Agents; In Situ Hybridization; Kidney Diseases; Kidney Glomerulus; Male; Middle Aged; Nephrotic Syndrome; Osmolar Concentration; Prednisolone; Proteinuria; Remission Induction; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1

Recent studies suggest that 3-hydroxy-3-methylglutaryl co-enzyme A reductase inhibitors (statins) exert their protective effects against cardiovascular diseases independently of their cholesterol-decreasing effects.. To clarify the effect of a statin on hypertensive nephrosclerosis.. We treated stroke-prone spontaneously hypertensive rats (spSHRs) chronically, starting at the age of 4 weeks, with cerivastatin (2 mg/kg per day by gavage) or vehicle. Physiological parameters, plasma chemistry and urine protein excretion were analysed. At 14 weeks of age, the rats had their kidneys removed for use in assays.. Compared with vehicle treatment, statin treatment reduced proteinuria and renal injury independently of blood pressure and cholesterol concentrations in spSHRs. Although expression of adhesion molecules and infiltration of inflammatory cells were not different whether or not cerivastatin treatment was used, renal fibrosis was significantly reduced in statin-treated spSHRs. We also found that expression of transforming growth factor-beta1 in kidneys was significantly inhibited in statin-treated spSHRs.. Cerivastatin prevents or retards hypertension-induced renal injury via inhibition of renal fibrosis and proteinuria. These results show the potential of statins as protective tools against proteinuric renal diseases, independent of their cholesterol-decreasing effects.

Topics: Animals; Blood Pressure; Genetic Predisposition to Disease; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertension; Inflammation; Kidney; Lipids; Male; Nephrosclerosis; Proteinuria; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Stroke; Transforming Growth Factor beta; Transforming Growth Factor beta1

Diabetic nephropathy is a leading cause of end-stage renal disease in industrialized countries. Previous studies have documented that angiotensin converting enzyme (ACE) inhibitors consistently reduce albuminuria and retard the progression of diabetic nephropathy. However, the involvement of angiotensin II in diabetic nephropathy is not fully understood.. In this study we compared the effects of CS-866, a new angiotensin II type 1 receptor antagonist, to that of an ACE inhibitor, temocapril hydrochloride, on the development and progression of diabetic nephropathy using Otsuka Long-Evans Tokushima fatty rats, a type II diabetes mellitus model animal.. High doses of CS-866 or temocapril treatment were found to significantly improve urinary protein and beta(2)-microglobulin excretions in diabetic rats. In electron microscopic analysis, loss of glomerular anionic sites, one of the causes of glomerular hyperpermeability in diabetic nephropathy, was found to be significantly prevented by CS-866 treatment. Light microscopic examinations revealed that both treatments ameliorated glomerular sclerosis and tubulointerstitial injury in diabetic rats. Furthermore, high doses of CS-866 or temocapril treatment significantly reduced the positive stainings for transforming growth factor-beta (TGF-beta), vascular endothelial growth factor, and type IV collagen in glomeruli of diabetic rats.. These results indicate that intrarenal angiotensin II type 1 receptor activation plays a dominant role in the development and progression of diabetic nephropathy. Our study suggests that CS-866 represents a valuable new drug for the treatment of diabetic patients with nephropathy.

Topics: Angiotensin II Type 1 Receptor Blockers; Animals; Anions; Diabetic Nephropathies; Disease Models, Animal; Imidazoles; Immunohistochemistry; Kidney Glomerulus; Male; Olmesartan Medoxomil; Proteinuria; Rats; Rats, Inbred OLETF; Severity of Illness Index; Tetrazoles; Thiazepines; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

Topics: Animals; Animals, Genetically Modified; Hypertension, Renal; Kidney; Proteinuria; Rats; Renal Artery; Renal Veins; Reperfusion Injury; Sirolimus; Time Factors; Transforming Growth Factor beta

Glucocorticoids are widely prescribed for renal diseases. It is believed that glucocorticoids attenuate immune-mediated renal diseases by suppressing the cell-mediated immune system. However, there is evidence that glucocorticoids influence the expression of such growth factors as vascular endothelial growth factor (VEGF), transforming growth factor-beta1 (TGF-beta1), and connective tissue growth factor (CTGF), which are known to influence the development or progression of renal diseases. Therefore, we undertook this study to determine whether glucocorticoids regulate proteinuria or extracellular matrix (ECM) production by altering these growth factors. Mesangial proliferative glomerulonephritis was induced in rats by intravenous injection of monoclonal antibody (OX-7), and dexamethasone (20 mg/kg) was administered intraperitoneally from the third to seventh disease day. Glomerular expression of VEGF, TGF-beta1, and CTGF, the amount of urinary protein, and glomerular ECM were measured on the seventh disease day. The nephritic group showed proteinuria and greater VEGF, TGF-beta1, and ECM production. Dexamethasone aggravated proteinuria (protein, 0.4 +/- 0.1 mg/mg creatinine in the NC group, 6.3 +/- 2.0 mg/mg creatinine in the DC group, and 21.1 +/- 1.9 mg/mg creatinine in the D-Dex group; P < 0.05) and diminished VEGF release (22 +/- 3 pg/mg total protein in the NC group, 292 +/- 26 pg/mg total protein in the DC group, and 198 +/- 23 pg/mg total protein in the D-Dex group; P < 0.05). Expression of TGF-beta1, CTGF, and ECM was not altered significantly by dexamethasone treatment. We found that glucocorticoid diminishes VEGF release and at the same time exacerbates proteinuria in rats with this type of glomerulonephritis.

Topics: Animals; Antibodies, Monoclonal; Body Weight; Connective Tissue Growth Factor; Creatinine; Drinking; Endothelial Growth Factors; Extracellular Matrix; Female; Glomerulonephritis, Membranoproliferative; Glucocorticoids; Growth Substances; Immediate-Early Proteins; Immunosuppressive Agents; Injections, Intravenous; Intercellular Signaling Peptides and Proteins; Lymphokines; Proteinuria; Rats; Rats, Sprague-Dawley; RNA, Messenger; Thy-1 Antigens; Transforming Growth Factor beta; Transforming Growth Factor beta1; Urination; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

In proteinuric nephropathies with increasingly severe defects of the glomerular filtering barrier, interstitial fibrogenesis is a major effector of scarring. An early event in this process is the peritubular accumulation of myofibroblasts that express alpha-smooth muscle actin (alpha-SMA) and contribute to abnormal matrix production. Common trigger factors are poorly understood. Enhanced protein trafficking may play a role by up-regulating inflammatory and fibrogenic genes in proximal tubular cells.. The remnant kidney model in rats was used to (1) analyze interactions between activated proximal tubular cells, peritubular cells expressing the myofibroblast marker, and inflammatory cells at time intervals (days 7, 14, and 30) after surgery, and (2) evaluate the effects of angiotensin-converting enzyme inhibitor (ACEi) on protein trafficking, fibrogenic signaling, and alpha-SMA expression.. Abnormal uptake of ultrafiltered proteins by proximal tubular cells (IgG staining) occurred at an early stage (day 7) and was subsequently associated with macrophage and alpha-SMA+ cell accumulation into the peritubular interstitium. alpha-SMA+ cells clustered with macrophages into the interstitium. These changes were associated with appearance of transforming growth factor-beta1 (TGF-beta1) mRNA in proximal tubular cells and in the infiltrating cells with time. At day 30, focal alpha-SMA staining also was found in the tubular cells and in peritubular endothelial cells on semithin ultracryosections. ACEi prevented both proteinuria and abnormal protein accumulation in tubular cells, as well as the inflammatory and fibrogenic reaction with peritubular alpha-SMA expression.. Profibrogenic signaling from both proximal tubular cells on challenge with filtered protein and inflammatory cells is implicated as a key candidate trigger of progressive tubulointerstitial injury.

Topics: Actins; Angiotensin-Converting Enzyme Inhibitors; Animals; Cell Division; Fibroblasts; Fibrosis; Immunoglobulin G; Kidney Tubules; Kidney Tubules, Proximal; Lisinopril; Macrophages; Male; Muscle, Smooth; Proteins; Proteinuria; Rats; Rats, Sprague-Dawley; RNA, Messenger; Staining and Labeling; Tissue Distribution; Transforming Growth Factor beta; Transforming Growth Factor beta1

The present study was designed to examine whether chronic adrenomedullin infusion has renoprotective effects in hypertensive renal failure and the mechanism by which chronic adrenomedullin infusion exerts its effects. Dahl salt-sensitive rats and Dahl salt-resistant rats were fed a high salt diet starting at 6 weeks of age. Recombinant human adrenomedullin or vehicle was infused for 7 weeks in 11-week-old Dahl salt-sensitive rats. Dahl salt-resistant rat was used as a control. After 7 weeks, untreated Dahl salt-sensitive rats were characterized by decreased kidney function, abnormal morphological findings, increased hormone levels, increased renal tissue angiotensin II levels, and altered mRNA expressions of transforming growth factor beta (TGF-beta) and components of the renin-angiotensin system compared with Dahl salt-resistant rats. Chronic adrenomedullin treatment significantly improved renal function (serum creatinine -87%, creatinine clearance +114%, urinary protein excretion -59%) and histological findings (glomerular injury score -54%) without changing mean arterial pressure compared with untreated Dahl salt-sensitive rats. Interestingly, long-term human adrenomedullin infusion decreased the endogenous rat adrenomedullin level (-97%) with a slight increase of human adrenomedullin level. Chronic adrenomedullin treatment also significantly inhibited the increase of plasma renin concentration (-269%), aldosterone level (-82%), and renal tissue angiotensin II levels (-60%). Furthermore, adrenomedullin infusion significantly decreased the increases of mRNA expressions of TGF-beta (- 63%), angiotensin-converting enzyme (-137%), renin (-230%), and angiotensinogen (-38%) in renal cortex. These results suggest that increased endogenous adrenomedullin plays a compensatory role in chronic hypertensive renal failure and that long-term adrenomedullin infusion has renoprotective effects in this type of hypertension model, partly via inhibition of the circulating and renal renin-angiotensin system.

Topics: Adrenomedullin; Angiotensin II; Animals; Creatinine; Drug Implants; Glomerulonephritis; Hormones; Hypertension; Kidney; Male; Peptides; Proteinuria; Rats; Rats, Inbred Dahl; Renal Insufficiency; Renin-Angiotensin System; RNA, Messenger; Sodium Chloride; Time Factors; Transforming Growth Factor beta

Many individuals develop a single or a few brief episodes of autoimmunity from which they recover. Mechanisms that quell pathologic autoimmunity following such a breakdown of self-tolerance are not clearly understood. In this study, we show that in nonautoimmune mice, dsDNA-specific autoreactive B cells exist but remain inactive. This state of inactivation in dsDNA-specific B cells could be disrupted by autoreactive Th cells; in this case T cells that react with peptides from the V(H) region of anti-DNA Abs (hereafter called anti-V(H) T cells). Immunization with anti-DNA mAb, its gamma-chain or peptides derived from its V(H) region induced anti-V(H) Th cells, IgG anti-dsDNA Ab, and proteinuria. The breakdown of B cell tolerance in nonautoimmune mice, however, was short-lived: anti-DNA Ab and nephritis subsided despite subsequent immunizations. The recovery from autoimmunity temporally correlated with the appearance of T cells that inhibited anti-DNA Ab production. Such inhibitory T cells secreted TGFbeta; the inhibition of anti-DNA Ab production by these cells was partly abolished by anti-TGFbeta Ab. Even without immunization, nonautoimmune mice possess T cells that can inhibit autoantibody production. Thus, inhibitory T cells in nonautoimmune mice may normally inhibit T-dependent activation of autoreactive B cells and/or reverse such activation following stimulation by Th cells. The induction of such inhibitory T cells may play a role in protecting nonautoimmune mice from developing chronic autoimmunity.

Topics: Amino Acid Sequence; Animals; Antibodies, Antinuclear; Antigen-Antibody Reactions; Autoantibodies; Autoantigens; Autoimmune Diseases; B-Lymphocyte Subsets; Cell Line; Clonal Anergy; Crosses, Genetic; DNA; Female; Histocompatibility Antigens Class II; Hybridomas; Lupus Erythematosus, Systemic; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Inbred NZB; Molecular Sequence Data; Proteinuria; Self Tolerance; Species Specificity; Spleen; T-Lymphocytes, Helper-Inducer; T-Lymphocytes, Regulatory; Transforming Growth Factor beta

A substantial body of experimental evidence suggests that protein loading causes activation of proximal tubular epithelial cells with consecutive interstitial fibrosis. These studies have mostly been performed using mammalian in vivo models of glomerular damage or tissue cultures of mammalian tubulointerstitial cells. The kidney of the axolotl contains not only closed nephrons, but also nephrons with ciliated peritoneal funnels called nephrostomes that have access to the peritoneal fluid. Injection of protein into the peritoneal cavity fails to expose closed nephrons to a protein load, but causes selective uptake and transient storage of proteins in tubular epithelial cells of nephrons with nephrostomes. The purpose of the present study was to determine whether (a) the axolotl kidney can be used as a model to assess protein uptake by tubular cells in vivo in the absence of glomerular damage, and (b) this is accompanied by any evidence of tubular epithelial cell activation and interstitial fibrosis.. Male and female axolotl (80 to 120 g of weight) were given a daily intraperitoneal injection of 1.5 mL endotoxin-free calf serum or saline as control. Kidneys were harvested after 4 or 10 days using perfusion fixation for light microscopy (fibrous tissue stain) and saline perfusion for immunohistochemistry (fibronectin, TGF-beta and collagen I).. The findings document selective storage of protein and lipids, progressive with time, in proximal tubular epithelial cells of nephrons draining the coelomic cavity. In addition, progressive focal accumulation of fibrous tissue was noted around protein-storing tubules. Immunohistochemical staining demonstrated the presence of fibronectin and TGF-beta in the tubular epithelial cells and interstitial cells.. The axolotl kidney provides a novel in vivo model to study tubulointerstitial activation and induction of interstitial fibrosis by protein loading. The findings are independent of alterations of glomerular function that may have potential confounding effects on peritubular hemodynamics, pO2, cell traffic, etc.

Topics: Ambystoma; Animals; Collagen Type I; Epithelial Cells; Female; Fibronectins; Fibrosis; Immunohistochemistry; Injections, Intraperitoneal; Kidney Tubules, Proximal; Male; Models, Animal; Proteinuria; Transforming Growth Factor beta

Local production of prostaglandins (PGs) in the kidney is increased in clinical and experimental diabetic nephropathy, but the role of PGs in the pathogenesis and progression of diabetic nephropathy has remained unclear. It is here shown that an orally active antagonist selective for the PGE receptor EP1 subtype potently prevents the progression of nephropathy in streptozotocin-induced diabetic rats. The effects are shown by ameliorated renal and glomerular hypertrophy, decreased mesangial expansion, inhibited transcriptional activation of transforming growth factor-beta (TGF-beta) and fibronectin, and complete suppression of proteinuria. In vitro, this agent completely inhibits TGF-beta and fibronectin upregulation in mesangial cells cultured under high-glucose conditions. These data indicate that the PGE2-EP1 system plays a crucial role in the development of diabetic renal injury in rats. It is further shown that both the EP1 antagonist and aspirin, a nonselective PG synthase inhibitor, markedly attenuate mesangial expansion, whereas only the EP1 antagonist inhibits glomerular hypertrophy and proteinuria, which suggests that these changes are caused by different mechanisms. This study reveals a potential usefulness of selective EP1 blockade as a novel therapeutic strategy for diabetic nephropathy and also brings a new insight into our understanding of this disease.

Topics: Animals; Aspirin; Autocrine Communication; Cells, Cultured; Cinnamates; Cyclooxygenase Inhibitors; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Dinoprostone; Disease Progression; Fibronectins; Glomerular Mesangium; Hypertrophy; Kidney; Kidney Glomerulus; Proteinuria; Rats; Rats, Wistar; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP1 Subtype; Tissue Distribution; Transforming Growth Factor beta; Up-Regulation

Potential determinants of chronic renal disease (CRD) progression were studied in male Munich-Wistar rats subjected to 5/6 nephrectomy and treated with candesartan (Csn; n = 30) or enalapril (Ena; n = 27) from 5 wk postsurgery. Despite control of systolic blood pressure (SBP; 24 wk: Csn = 143 +/- 9; Ena = 148 +/- 8 mmHg), urinary protein excretion rates (U(pr)V) increased over 24 wk (Csn = 92 +/- 10; Ena = 99 +/- 8mg/day). Glomerulosclerosis scores (GS) at 24 wk were similar for Csn (42 +/- 7%) vs. Ena (42 +/- 4%), values close to those of untreated controls at 12 wk (43 +/- 4%). At 24 wk, SBP and UprV correlated strongly with GS, together accounting for 72% of the variance in GS. Renal cortex mRNA levels (determined by competitive RT-PCR) for transforming growth factor (TGF)-beta1 and monocyte chemoattractant protein (MCP)-1 were elevated in Csn and Ena at 12 wk and remained higher at 24 wk vs. sham. Strong correlations were evident among TGF-beta1, MCP-1, and interleukin-1beta and renal injury at 24 wk. Cns and Ena are thus equally effective renoprotective agents in this model. During renin-angiotensin system inhibition, renoprotection is dependent on control of both SBP and UprV. Incomplete suppression of renal cytokine gene expression may also contribute to CRD progression.

Topics: Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Chemokine CCL2; Enalapril; Endothelin-1; Interleukin-1; Kidney Cortex; Kidney Failure, Chronic; Male; Nephrectomy; Proteinuria; Rats; Rats, Wistar; Renin-Angiotensin System; RNA, Messenger; Tetrazoles; Transforming Growth Factor beta; Transforming Growth Factor beta1

Glomerular mesangial cell proliferation and/or mesangial matrix accumulation characterizes many progressive renal diseases. Rats with progressive mesangioproliferative glomerulonephritis were treated from day 3 to day 7 after disease induction with a high-affinity oligonucleotide aptamer antagonist against platelet-derived growth factor-B chain (PDGF-B). In comparison with nephritic rats that received vehicle or a scrambled aptamer, treatment with the PDGF-B aptamer led to a significant reduction of mesangioproliferative changes, glomerular hypertrophy, podocyte damage, and glomerular macrophage influx on day 8. Both nephritic control groups subsequently developed progressive proteinuria and decreased renal function. On day 100, glomerulosclerosis, tubulointerstitial damage, glomerular and interstitial accumulation of types III and IV collagen, and overexpression of transforming growth factor-beta were widespread. All of these chronic changes were prevented in rats that received the PDGF-B aptamer, and their functional and morphologic parameters on day 100 were largely indistinguishable from non-nephritic rats. These data provide the first evidence for a causal role of PDGF in the pathogenesis of renal scarring and point to a new, highly effective therapeutic approach to progressive, in particular mesangioproliferative, renal disease.

Topics: Animals; Blood Pressure; Cicatrix; Collagen; Extracellular Matrix; Glomerulonephritis, Membranoproliferative; Kidney; Macrophages; Male; Microscopy, Electron; Monocytes; Proteinuria; Proto-Oncogene Proteins c-sis; Rats; Rats, Wistar; Transforming Growth Factor beta

To assess if the renal damage observed in rats with diabetes and hypertension is due to hemodynamic or metabolic changes, a progressive aortic constriction between the two renal arteries has been done in streptozotocin-induced diabetic rats (constriction + diabetes group) and in nondiabetic rats (constriction group). This model allows us to study two kidneys subjected to different perfusion pressure (PP) in the same metabolic environment. One-month-old rats (100-120 g body wt) were subjected to the aortic constriction procedure. Three months after constriction, glomerular filtration rate and renal plasma flow were similar in both kidneys of the two groups. PP was greater in the kidney placed over the ligature [constriction high-pressure kidney (CH) or constriction + diabetic high-pressure kidney (DH)] than in the one placed below the ligature [constriction low pressure (CL) or constriction + diabetic low pressure (DL)]. Proteinuria was higher in the CH than in the CL kidneys (512 +/- 61 vs. 361 +/- 38 microg/30 min, respectively) and much higher in the DH kidney (770 +/- 106 microg/30 min). Renal fibrosis was measured in tissue sections stained with Syrius red using a computer-assisted image analysis system. DH and DL kidneys showed higher corpuscular cross-sectional and capillary tuft areas than the CH and CL ones. The DH kidney showed slight mesangial expansion and thickening of the capillary walls, which were more pronounced in the former. Most renal corpuscles from CH and DH groups were nearly normal in morphology appearance, and only in some instances a slight increment in mesangium was observed. Transforming growth factor-beta1 (TGF-beta1) immunostaining revealed that DH kidneys showed the highest glomerular expression. We concluded that 1) diabetic animals develop glomerular but not interstitial fibrosis to a greater extent than nondiabetic animals and that this lesion principally occurs in the hypertensive kidney (DH), and 2) increased TGF-beta expression is associated with diabetic renal damage.

Topics: Animals; Aorta; Blood Pressure; Carotid Arteries; Constriction; Diabetes Mellitus, Experimental; Diuresis; Femoral Artery; Fibrosis; Glomerular Filtration Rate; Hypertension; Kidney; Kidney Glomerulus; Male; Natriuresis; Potassium; Proteinuria; Rats; Rats, Wistar; Renal Circulation; Transforming Growth Factor beta; Transforming Growth Factor beta1

The central process in chronic renal failure is the progressive accumulation of extracellular matrix in the glomeruli and in the tubulo-interstitial space, resulting in renal fibrosis. Transforming growth factor-beta1 (TGF-beta1) up-regulation plays a major role in the genesis of renal fibrosis. Endoglin is a membrane glycoprotein that binds TGF-beta1 and TGF-beta3 with high affinity. An increased level of endoglin immunostaining has been demonstrated previously in biopsies from patients with chronic progressive renal disease. We have assessed the expression of endoglin in the rat 5/6th renal mass reduction (RMR) model.. One, 3 and 5 months after RMR, mean arterial pressure and renal function were measured, animals were sacrificed, renal fibrosis was evaluated quantitatively and the expression of endoglin was assessed by western blot, northern blot and immunohistochemistry.. RMR induced a progressive increase in mean arterial pressure and urinary protein excretion. Renal corpuscular area, and mesangial and interstitial fibrosis increased with time after RMR. Immunohistochemical staining for endoglin demonstrated its expression mainly on the endothelial surface of major vessels. In kidneys 1 and 3 months after RMR, the expression of endoglin in renal corpuscles was limited to Bowman's parietal epithelium. In rats 5 months after RMR, the immunoexpression in glomerular endothelium was more marked. Northern blot analysis revealed that rats with RMR showed an increase in the expression of mRNA for endoglin, only at 5 months after RMR. Western blot analysis gave a different time course: a marked increase in the first month, a decrease in the 3rd month and a further increase in the 5th month after RMR.. The present study demonstrates increased endoglin expression in rats with severe hypertension and renal damage. This increased endoglin expression coincides with the period of higher renal damage and renal dysfunction.

Topics: Animals; Antigens, CD; Blood Pressure; Creatinine; Endoglin; Fibrosis; Immunohistochemistry; Kidney; Kidney Glomerulus; Male; Nephrectomy; Nephritis, Interstitial; Proteinuria; Rats; Rats, Wistar; Receptors, Cell Surface; Renal Artery; Transforming Growth Factor beta; Vascular Cell Adhesion Molecule-1

In addition to its well-known role in degrading fibrin, recent evidence suggests that plasmin degrades matrix proteins and activates prometalloproteinases. Plasmin is generated from plasminogen by tissue plasminogen activator (t-PA). We hypothesized that t-PA treatment increases plasmin generation in nephritic glomeruli and degrades pathological matrix leading to a therapeutic reduction in matrix accumulation.. Anti-Thy-1 nephritis was induced by injection of OX-7 antibody. Rats were given twice daily intravenous injections of saline (disease control group) or human recombinant t-PA (rt-PA; 1 mg/kg body weight) on days 3 through 5. Proteinuria, glomerular matrix protein staining, and glomerular mRNA levels for transforming growth factor-beta 1 (TGF-beta 1), fibronectin, and plasminogen activator inhibitor type 1 (PAI-1) were evaluated at day 6. Localization of rt-PA, plasmin generation by glomeruli in vitro, and glomerular production and content of active TGF-beta1 were also investigated.. Compared with disease control animals, proteinuria and staining score for periodic acid-Schiff (2.75 +/- 0.17 vs. 1.41 +/- 0.09), fibronectin-EDA+ (19 +/- 2 vs. 14 +/- 1), laminin (35 +/- 2 vs. 25 +/- 2), type I collagen (33 +/- 1 vs. 21 +/- 3), and type IV collagen (27 +/- 2 vs. 23 +/- 1) were significantly reduced in treated rats (P < 0.01). Glomerular TGF-beta 1, fibronectin, and PAI-1 mRNA levels were unchanged. rt-PA colocalized with fibrin along glomerular capillary walls and in the mesangium. Nephritic glomeruli in vitro had decreased plasmin activity, which was elevated by an in vivo presacrifice injection of rt-PA. Glomerular production and content of active TGF-beta 1 were unchanged by the rt-PA injection.. : These results show that injected rt-PA binds to fibrin in nephritic glomeruli, thus increasing plasmin generation and promoting pathological matrix degradation without activating latent TGF-beta. Agents that increase plasmin generation, such as t-PA, may have potential as antifibrotic therapies.

Topics: Animals; Cells, Cultured; Extracellular Matrix; Fibrin; Fibrinogen; Fibrinolysin; Fibronectins; Gene Expression; Glomerulosclerosis, Focal Segmental; Kidney Glomerulus; Male; Plasminogen Activator Inhibitor 1; Plasminogen Activators; Proteinuria; Rats; Rats, Sprague-Dawley; RNA, Messenger; Thy-1 Antigens; Tissue Plasminogen Activator; Transforming Growth Factor beta; Transforming Growth Factor beta1

The aim of this study was to evaluate whether the infiltrating T-lymphocyte can be a predictor in the disease progression of IgA nephropathy (IgAN). Twenty children with IgAN, followed for more than 5 years, were divided into progressive (n=5) and non-progressive groups (n=15). We assessed glomerular and interstitial infiltration of T-lymphocytes (CD4+ and CD8+ cells) and expression of alpha-smooth muscle actin (alpha-SMA) and transforming growth factor-beta (TGF-beta) using an indirect immunofluorescence method on the renal biopsies. We analyzed their relationship to the degree of proteinuria, histological changes, and prognosis. The number of CD8+ cells in glomeruli and in interstitium was higher in the progressive group than in the non-progressive group. The glomerular alpha-SMA staining was more intensive in the progressive group than in the non-progressive group. Urinary protein and the degree of histological changes were also higher in the progressive group than in the non-progressive group. Among these markers, the number of glomerular CD8+ cells was the most apparent difference between the two groups. In conclusion, these results indicate that the number of glomerular CD8+ cells is the most sensitive predictor of disease progression in childhood IgAN.

Topics: Actins; Adolescent; CD8 Antigens; Child; Disease Progression; Female; Fluorescent Antibody Technique; Glomerular Mesangium; Glomerulonephritis, IGA; Humans; Kidney Glomerulus; Male; Muscle, Smooth; Prognosis; Proteinuria; Retrospective Studies; T-Lymphocytes; Transforming Growth Factor beta

Acute episodes of severe renal ischemia result in acute renal failure (ARF). These episodes are followed by a characteristic recovery and repair response, whereby tubular morphology and renal function appear completely restored within approximately 1 mo. However, the chronic effects of such an injury have not been well studied. Male rats were subjected to 60-min bilateral ischemia followed by reperfusion, yielding a characteristic injury. Postischemic animals manifested severe diuresis, peaking at 1 wk postinjury (volume: >45 ml/day, ARF vs. 18 ml/day, sham; P < 0.05). Urine flow subsequently declined but remained significantly elevated vs. sham animals for a 40-wk period. The prolonged alteration in urinary concentrating ability was attributable, in part, to a diminished capacity to generate a hypertonic medullary interstitium. By week 16, proteinuria developed in the post-ARF group and progressed for the duration of the study. Histological examination revealed essentially normal tubular morphology at 4 and 8 wk postinjury but the development of tubulointerstitial fibrosis at 40 wk. Transforming growth factor (TGF)-beta1 expression was elevated at 40 wk, but not at 4 and 8 wk postinjury. Microfil analysis revealed an approximately 30-50% reduction in peritubular capillary density in the inner stripe of the outer medulla at 4, 8, and 40 wk in post-ARF groups vs. sham animals. In addition, post-ARF rats manifested a significant pressor response to a low dose of ANG II (15 ng x kg(-1) x min(-1)). We hypothesize that severe ischemic injury results in a permanent alteration of renal capillary density, contributing to a urinary concentrating defect and the predisposition toward the development of renal fibrosis.

Topics: Acute Kidney Injury; Animals; Blood Pressure; Capillaries; Dehydration; Diuresis; Fibrosis; Ischemia; Kidney; Kidney Concentrating Ability; Kidney Tubules; Male; Natriuresis; Osmolar Concentration; Proteinuria; Rats; Rats, Sprague-Dawley; Reperfusion Injury; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1; Urine

Using angiotensin II (AngII) type 1A receptor-deficient mice [AT1(-/-)], in which we induced protein overload nephropathy, we explored the potential implication of AngII and endothelin-1 (ET-1) in the tubulointerstitial damage because of persistent proteinuria. At day 7, AT1(-/-) showed marked proteinuria to a similar extent to that of wild-type mice (WT). However, at day14, AT1(-/-) had significantly less proteinuria, renal damage, transforming growth factor-beta, and matrix mRNA expression and mortality. AT1(-/-) also showed a significant diminution in the activation of the transcriptional factors nuclear factor-kappaB and AP-1. Unexpectedly, AT1(-/-) had a higher interstitial infiltration than WT. The administration of the angiotensin-converting enzyme inhibitor quinapril to WT caused a marked improvement in proteinuria and renal lesions, resembling that seen in untreated AT1(-/-). However, the interstitial infiltration persisted in AT1(-/-) when treated with quinapril. Because ET-1 may participate in the recruitment of mononuclear cells, we also studied the implication of this peptide. AT1(-/-) had a significantly higher ET-1 expression in tubular epithelial cells than WT. The administration of the dual ETA/ETB antagonist bosentan to AT1(-/-) considerably reduced the interstitial infiltrates. Bosentan also exerted a beneficial effect on proteinuria, renal lesions, and mortality in WT. These data show that in overload nephropathy, proteinuria and renal lesions are, to a large extent, AngII-dependent. The up-regulation of ET-1 in tubular epithelial cells in AT1(-/-), associated with interstitial infiltrates, suggests that the combination of drugs interfering with both vasopeptides may be of therapeutic interest in renal diseases with severe proteinuria and tubulointerstitial damage.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Bosentan; Endothelins; Extracellular Matrix; Isoquinolines; Kidney; Kidney Diseases; Kidney Tubules; Kinetics; Mice; Mice, Inbred C57BL; Mice, Knockout; NF-kappa B; Proteinuria; Quinapril; Receptor, Angiotensin, Type 1; Receptors, Angiotensin; Reference Values; RNA, Messenger; Serum Albumin, Bovine; Sulfonamides; Tetrahydroisoquinolines; Transcription Factor AP-1; Transforming Growth Factor beta

Sustained high output release of Nitric oxide (NO) as result of activation of inducible nitric oxide synthase (iNOS), and increased production of the antiproliferative/profibrotic cytokine transforming growth factor-beta1 (TGF-beta1) are well documented in glomerulonephritis. Modulation of iNOS activity and of TGF-beta1 production can therefore be viewed as anti-inflammatory strategies. The present study employed all-trans retinoic acid (atRA) which is known to have anti-inflammatory effects and to modulate expression of iNOS and TGF-beta1, in order to explore its effect on iNOS enzyme activity and TGF-beta1 production in anti-GBM antibody induced glomerulonephritis. Glomerulonephritis was induced in Lewis rats by injection of anti-GBM antibody. A group of nephritic rats were given daily administration of atRA for 14-16 days. Extent of proteinuria was assessed by measuring urine protein and creatinine excretion. iNOS enzyme activity was measured by calculating conversion of L[14C]arginine to L-[14C]citrulline in glomerular protein lysates. Levels of TGF-beta1 in glomerular protein lysates were measured by quantitative ELISA. Levels of proliferating nuclear antigen (PCNA), TGF-beta receptor II (TGFbeta-RII), and fibronectin were assessed by Western blot analysis. Glomerular iNOS activity in atRA treated nephritic animals was attenuated in comparison to that in nephritic controls that were not. Glomerular expression of PCNA was also reduced. Levels of TGF-beta1 were increased in glomeruli of atRA treated nephritic animals. In these animals, there was no change in glomerular levels of TGF-beta receptor II (TGFbeta-RII) or fibronectin. and there was no reduction in urine protein excretion. These results suggest that atRA attenuates iNOS activity and proliferation in glomeruli of nephritic animals. The failure of atRA treatment to reduce proteinuria could be due to the increase in TGF-beta1 levels and to inhibition of iNOS-driven NO production.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antibodies; Autoantibodies; Cell Division; Disease Models, Animal; Glomerulonephritis; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Proliferating Cell Nuclear Antigen; Proteinuria; Rats; Rats, Inbred Lew; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tretinoin

Hyperlipoproteinemia can aggravate glomerulosclerosis and chronic tubulointerstitial (ti) damage in kidneys without primary immunologic disease. We evaluated whether the effect of hyperlipidemia on progression of renal damage differed between kidneys without preexisting glomerular disease and kidneys with mesangioproliferative glomerulonephritis and whether the renal actions of hyperlipidemia were dependent on oxidant-antioxidant balance. Hyperlipidemia was induced by high-fat and high-cholesterol diet in uninephrectomized rats. In rats without glomerulonephritis, hyperlipidemia led to a rise in glomerular and ti generation of reactive oxygen species (ROS). Oxygen radicals were mainly generated by enhanced xanthine oxidoreductase (XO), which rose with protein concentration and activity during hyperlipidemia; concurrently, glomerulosclerosis and chronic ti injury were noticed during hyperlipidemia [ti damage (% of total tubulointerstitium (TI) after 150 days): normolipidemia 0.1 +/- 0% vs. hyperlipidemia 3.4 +/- 0. 9%; P < 0.05]. In mesangioproliferative Thy-1 nephritis, ti injury was significantly accelerated by hyperlipidemia (ti damage after 150 days: normolipidemic Thy-1 nephritis 2.5 +/- 0.6% vs. hyperlipidemic Thy-1 nephritis 12.5 +/- 3.1%; P < 0.05). Antioxidant enzyme activities decreased and XO activity rose markedly in the TI (XO activity in TI after 150 days: normolipidemic Thy-1 nephritis 2.2 +/- 0.5 vs. hyperlipidemic Thy-1 nephritis 4.5 +/- 0.7 cpm/microg protein; P < 0.05). In hyperlipidemic Thy-1 nephritis rats, which had a higher urinary protein excretion than normolipidemic rats, hypochlorite-modified proteins, an indirect measure for enhanced myeloperoxidase activity, were detected in renal tissue and in urine, respectively. During hyperlipidemia, chronic damage increased in renal TI. Enhanced generation of ROS, rise in oxidant enzyme activity, and generation of hypochlorite-modified proteins in renal tissue and urine were noticed. These data suggest that oxidant stress contributed to the deleterious effects of hyperlipidemia on the renal TI.

Topics: Animals; Cholesterol, Dietary; Desmin; Dietary Fats; Glomerulonephritis, Membranoproliferative; Glomerulosclerosis, Focal Segmental; Hyperlipidemias; Kidney Cortex; Kidney Glomerulus; Luminescent Measurements; Male; Multienzyme Complexes; NADH, NADPH Oxidoreductases; NADPH Oxidases; Nephrectomy; Nephritis, Interstitial; Oxidative Stress; Proteinuria; Rats; Rats, Wistar; Reactive Oxygen Species; RNA, Messenger; Superoxide Dismutase; Transforming Growth Factor beta

In this study we investigated the effect of heparin on renal injury and renal transforming growth factor-beta (TGF-beta) production in adriamycin (AD)-injected rats. Thirty-nine female Wistar rats were injected with AD (3.5 mg/kg body weight, i.v.) and 27 with 0.15 M NaCl solution (group C). Fifteen days later we started to inject heparin, 500 U/day, s.c., in 20 of the AD-injected animals (AD-H group). Three months after beginning treatment, urine samples were collected to quantify albumin, creatinine and TGF-beta. The rats were killed and the kidneys removed for histological, immunohistochemical, ELISA and RNA studies. All AD-injected animals showed structural renal changes (p < 0.05). However, the glomerular alterations were less intense in rats from group AD-H (p < 0.05). The percentage of glomerulosclerosis was 0.11 +/- 0.08 in group C, 14.7 +/- 12.8 in group AD (treated only with AD) and 3.42 +/- 2.3 in group AD-H. Renal cortex immunostaining for TGF-beta and mRNA content of this polypeptide was higher in both groups of animals injected with AD compared to controls (p < 0.05). These animals also presented a higher rate of urinary TGF-beta excretion (p < 0.05), which was 202 +/- 11 in group C, 1,103 +/- 580 in group AD and 1,564 +/- 328 pg/mg Ucreat in group AD-H. However, TGF-beta activity in the glomerular-conditioned media from the rats of group AD was higher than in the glomerular-conditioned media from the rats of group AD-H. In conclusion, treatment with heparin reduces glomerular damage in rats with AD-induced nephropathy but does not modify tubulointerstitial lesions or the renal production of TGF-beta.

Topics: Angiotensin II; Animals; Blood Pressure; Creatinine; Doxorubicin; Endothelins; Female; Fibronectins; Heparin; Immunohistochemistry; Kidney Diseases; Kidney Glomerulus; Proteinuria; Rats; Rats, Wistar; RNA, Messenger; Transforming Growth Factor beta

Chronic inhibition of nitric oxide synthase (NOS) is known to cause renal parenchymal injury with systemic hypertension. To elucidate the pathogenetic mechanism in renal damage induced by NOS inhibition, N(omega)-nitro-L-arginine methyl ester (L-NAME) was given orally for 12 wk in Wistar rats, and the roles of tissue renin-angiotensin system and transforming growth factor-beta1 (TGF-beta1) were investigated. BP and urinary protein excretion increased significantly in L-NAME rats compared with control rats, and glomerulosclerosis and interstitial fibrosis developed. In L-NAME rats, the cortical tissue levels of angiotensin-converting enzyme activity and angiotensin II were significantly higher than those in control rats. The cortical mRNA expressions of both TGF-beta1 and fibronectin were significantly elevated in L-NAME rats. Immunohistochemically, increased expressions of both fibronectin and alpha-smooth muscle actin were also revealed in L-NAME rats. In L-NAME rats, these histologic injuries and the increased expression of TGF-beta1 were equally ameliorated by either angiotensin-converting enzyme inhibitor or angiotensin II type 1 receptor antagonist, but not by hydralazine. In conclusion, the locally activated renin-angiotensin system in connection with the increased TGF-beta1 expression is a major pathogenetic feature of renal injury in chronically NOS-inhibited rats.

Topics: Actins; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Enzyme Inhibitors; Fibronectins; Imidazoles; Imidazolidines; Kidney; Kidney Cortex; Kidney Diseases; Male; Muscle, Smooth; NG-Nitroarginine Methyl Ester; Nitric Oxide Synthase; Proteinuria; Rats; Rats, Wistar; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Renin-Angiotensin System; RNA, Messenger; Time Factors; Transforming Growth Factor beta

Proteinuria is now accepted to be not just a sign of renal disease but also a contributory factor to the development of progressive tubulointerstitial fibrosis. Excellent correlations between the degree of proteinuria and rate of decline of glomerular filtration rate have been demonstrated. What has been investigated less is whether the type of protein found in the urine is important. Using transformed and primary human proximal tubular epithelial cells, we have investigated the binding of albumin and retinol binding protein to plasma membrane preparations and studied the response of the intact cells to increasing concentrations of these same proteins. We have preliminary evidence for differences in the pattern of binding of these two proteins to the plasma membrane receptors and also for differential release of pro-inflammatory cytokines from intact cells. These in vitro results, along with those of other groups, and some recent clinical findings suggest that the quality of proteinuria may play a role in the early development of interstitial fibrosis. Furthermore, the use of such in vitro model systems based on human proximal epithelial cell culture can provide a means of evaluating the potential significance of different markers of tubular damage.

Topics: Cell Line; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Interleukin-6; Proteinuria; Renal Insufficiency; Retinol-Binding Proteins; Retinol-Binding Proteins, Plasma; Serum Albumin; Transforming Growth Factor beta

Transforming growth factor-beta1 (TGF-beta1) is a multifunctional cytokine. Glomerular cells and tubular epithelial cells secrete and respond to TGF-beta1. A close association between elevated levels of TGF-beta1 and the development of glomerulonephritis, glomerulosclerosis, and tubular hypertrophy has been documented. The role of TGF-beta1 in proteinuria is not well understood.. Isolated rat glomeruli were incubated in medium alone or with TGF-beta1 (1 to 10 ng/mL) and TGF-beta1 + 200 U/mL of superoxide dismutase (SOD) or 1 mmol/L of dimethylthiourea (DMTU) scavengers of superoxide and hydroxyl radicals, respectively, for up to 60 minutes at 37 degrees C. Glomerular albumin permeability (Palb) was calculated from the volumetric response of glomeruli to an oncotic gradient using videomicroscopy.. One or 2.5 ng/mL of TGF-beta1 had no effect on Palb (0.18 +/- 0.08, N = 17; 0.18 +/- 0. 079, N = 20 vs. control 0.00 +/- 0.06, N = 25), whereas 5 or 10 ng/mL of TGF-beta1 caused a significant increase in Palb (0.31 +/- 0. 09, N = 20; 0.33 +/- 0.06, N = 23) within 15 minutes. The effect of 10 ng/mL of TGF-beta1 on Palb increased further after 30, 45, or 60 minutes of incubation (0.43 +/- 0.06, N = 24; 0.53 +/- 0.06, N = 25; 0.74 +/- 0.075, N = 21). The TGF-beta1-induced increase in Palb (0. 75 +/- 0.065, N = 15) was blocked by SOD (0.07 +/- 0.14 N = 15) or by DMTU (0.04 +/- 0.13, N = 15). Incubation of glomeruli with the carrier medium (4N HCl) in which TGF-beta1 is dissolved and SOD or DMTU alone did not affect Palb.. Elevated levels of TGF-beta1 derived from glomerular or extraglomerular sources are capable of increasing glomerular Palb via superoxide and hydroxyl radicals and may lead to proteinuria in vivo.

Topics: Animals; Biological Transport; Free Radical Scavengers; Hydroxyl Radical; In Vitro Techniques; Kidney Glomerulus; Male; Proteinuria; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Serum Albumin, Bovine; Superoxide Dismutase; Superoxides; Thiourea; Transforming Growth Factor beta

Renal ischaemia-reperfusion (IR) injury is an inevitable consequence of transplantation and contributes to later graft fibrosis. This study aimed to elucidate the possible mechanisms by studying the expression of genes associated with extracellular matrix (ECM) turnover.. Male Wistar rats underwent laparotomy, clamping of the right renal pedicle for 45 min, and left nephrectomy. Control animals underwent left nephrectomy only, or had no operation. Animals were killed at 8, 16 and 24 weeks and messenger RNA was extracted from renal tissue. Genes of interest were amplified and then quantified in an enzyme-linked immunosorbent assay system with levels expressed as a ratio to a known housekeeping gene (GAPDH).. Experimental animals developed progressive proteinuria from 16 weeks onwards. At 8 weeks after IR injury, gene levels of matrix metalloproteinase (MMP) 2, an ECM-degrading enzyme, were significantly increased. Levels then fell progressively. This was associated with increasing expression of tissue inhibitor of metalloproteinases (TIMP) 1, an inhibitor of MMP-2, and of transforming growth factor (TGF) beta, a profibrotic cytokine, by 24 weeks following injury.. These results suggest that, after an initial phase of increased ECM turnover following IR injury, the balance turns towards one of reduced degradation. This is likely to be an important mechanism in the subsequent development of fibrosis.

Topics: Animals; Gene Expression; Kidney; Laparotomy; Male; Matrix Metalloproteinase 2; Proteinuria; Rats; Rats, Wistar; Reperfusion Injury; RNA, Messenger; Tissue Inhibitor of Metalloproteinase-1; Transforming Growth Factor beta

Chronic allograft nephropathy (CAN) remains a major problem in clinical transplantation. It has been associated with increased transforming growth factor (TGF-beta1). Our goal was to correlate CAN and levels of TGF-beta1 by using a novel competitive quantitative for reverse transcription-polymerase chain reaction-ELISA (RT-PCR-ELISA) assay.. We studied 12 transplantation patients (posttransplant time: 36.5+/-11.2 months, range (r): 13-52) with stable creatinine and blood pressure and varied proteinuria. A Kidney biopsy was performed in all patients. Six patients with acute tubular necrosis (ATN) immediately after transplantation were used as controls. Histopathological evaluation was based on Banff working classification criteria. We designed an heterologous RNA competitor (IC) for RT-PCR-ELISA, which co-amplified with the same primer as TGF-beta1. Products were viewed on 96-well plates labeled with probes for IC at the desired sequence.. Results were expressed as the number of TGF-beta1 copies/microg of total RNA. Six patients showed more than 1000 mg/24 hr proteinuria (2446+/-1421 mg/24 hr, r: 1200-5000) higher CAN Banff scores, and the other six presented <1,000 mg/24 hr (348+/-267 mg/24 hr, r: 114-800). This difference was significant (P=0.01). There were not significant differences in posttransplant time, creatinine, or blood pressure between groups. TGF-beta1 levels by RT-PCR-ELISA were statistically significant (6038+/-5317, r: 1239-12100 versus 177+/-119.7, r: 51-400, P=0.04). The control group showed levels of 228+/-111, r. 140-444, P=0.04) with significant difference only for the higher proteinuria group (P=0.03).. This study showed that those patients with elevated CAN scores and higher proteinuria levels had higher TGF-beta1 intragraft expression.

Topics: Adolescent; Adult; Base Sequence; Biomarkers; Biopsy, Needle; Blood Pressure; Creatinine; DNA Primers; Enzyme-Linked Immunosorbent Assay; Female; Humans; Kidney Transplantation; Kidney Tubular Necrosis, Acute; Living Donors; Male; Middle Aged; Molecular Sequence Data; Proteinuria; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tissue Donors; Transcription, Genetic; Transforming Growth Factor beta

Systemic hypertension is a risk factor for progression of renal disease. However, it is not clear whether hypertension has an effect on healing or regression of immune-mediated glomerular damage. To evaluate this effect, we applied a model of glomerulonephritis in rats with two-kidney, one-clip hypertension and studied the effect of hypertension on the healing process of this nephritis.. The anti-thymocyte serum (ATS) glomerulonephritis was induced in rats six weeks after initiation of two-kidney, one-clip hypertension, when blood pressure was already increased. Renal structure and function were examined six weeks later. Glomerular expression of alpha smooth muscle actin, the cell cycle inhibitor p27Kip1, and transforming growth factor-beta (TGF-beta) was evaluated by Western blotting. Glomerular proliferation, monocyte infiltration, and fibronectin were examined by immunohistochemistry.. Decreased survival, an increase of proteinuria, as well as increased glomerular and tubulointerstitial damage, were found in hypertensive rats compared with normotensive rats. Expression of fibronectin, alpha-smooth muscle actin, TGF-beta, and p27Kip1 was increased in the nonclipped kidney. Complete healing of the glomerular changes associated with the nephritis occurred in normotensive nephritic rats. Surprisingly, complete healing of the nephritis was also found in the clipped as well as nonclipped kidneys of renovascular hypertensive rats. No significant differences could be found for survival, proteinuria, glomerular size, proliferation, monocyte/macrophage infiltration, sclerosis, tubulointerstitial damage, as well as expression of alpha-smooth muscle actin, TGF-beta, fibronectin, and p27Kip1 between hypertensive rats with and without nephritis.. These data demonstrate that renovascular hypertension does not influence healing of the glomerular lesions in the anti-thymocyte serum nephritis. This is a rather surprising observation and leaves the question open of which role, in fact, blood pressure may have on the reparative phase of an acute glomerulonephritis, or whether its role depends on the type of glomerulonephritis.

Topics: Animals; Blood Pressure; Cell Cycle Proteins; Cell Division; Cyclin-Dependent Kinase Inhibitor p27; Glomerular Filtration Rate; Glomerulosclerosis, Focal Segmental; Hypertension, Renal; Hypertrophy; Immunoglobulin G; Kidney Glomerulus; Macrophages; Male; Microtubule-Associated Proteins; Monocytes; Proteinuria; Rats; Rats, Sprague-Dawley; Survival Analysis; Thymus Gland; Transforming Growth Factor beta; Tumor Suppressor Proteins

The renin-angiotensin system (RAS) and endothelin system may both play a role in the pathogenesis of progressive renal injury. The aims of the present study were 3-fold: first, to explore the possible benefits of dual blockade of the RAS with an ACE inhibitor and an angiotensin type 1(AT1) receptor antagonist; second, to examine the relative efficacy of endothelin A receptor antagonism (ETA-RA) compared with combined endothelin A/B receptor antagonism (ETA/B-RA); and third, to assess whether interruption of both RAS and endothelin system had any advantages over single-system blockade. Subtotally nephrectomized rats were studied as a model of progressive renal injury and randomly assigned to one of the following treatments for 12 weeks: perindopril (ACE inhibitor), irbesartan (AT1 receptor antagonist), BMS193884 (ETA-RA), bosentan (ETA/B-RA), and a combination of irbesartan with either perindopril or BMS193884. Treatment with irbesartan or perindopril was associated with an improved glomerular filtration rate and reductions in blood pressure, urinary protein excretion, glomerulosclerosis, and tubular injury in association with reduced gene expression of transforming growth factor-beta(1) and matrix protein type IV collagen. The combination of irbesartan with perindopril was associated with further reductions in blood pressure and urinary protein excretion. No beneficial effects of either BMS193884 or bosentan were noted. Furthermore, the addition of BMS193884 to irbesartan did not confer any additional benefits. These findings suggest that the RAS but not the endothelin system is a major mediator of progressive renal injury after renal mass reduction and that the combination of an AT1 receptor antagonist with an ACE inhibitor may have advantages over the single agent of RAS blocker treatment.

Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Blood Pressure; Collagen; Disease Models, Animal; Disease Progression; Drug Therapy, Combination; Endothelin Receptor Antagonists; Endothelin-1; Glomerular Filtration Rate; Kidney; Male; Nephrectomy; Proteinuria; Rats; Rats, Sprague-Dawley; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Receptor, Endothelin A; Receptor, Endothelin B; Renal Insufficiency; Renin-Angiotensin System; RNA, Messenger; Severity of Illness Index; Transforming Growth Factor beta

The recently discovered arachidonic acid derivatives, isoprostanes, are increased in pathological conditions associated with oxidative stress, such as diabetes. No role has yet been described for isoprostanes during the development of diabetic nephropathy. Cell culture in high ambient glucose has been used as a model in elucidating cellular mechanisms underlying diabetic nephropathy. Among the growth factors involved in the effect of high glucose, transforming growth factor-beta (TGF-beta) has been described as playing a key role in the development of nephropathy.. Streptozotocin-induced diabetic rats were supplemented in their diet with the antioxidant vitamin E (1000 U/kg diet). Blood and urine samples were taken to determine renal function and isoprostane concentration, as determined by gas chromatography/mass spectrometry. Glomerular mesangial and endothelial cells were cultured in high ambient glucose to determine the synthesis of isoprostanes and the role of isoprostanes in high glucose-induced synthesis of TGF-beta.. Streptozotocin-induced diabetic rats had marked increases in plasma levels and urinary excretion rates of F(2)-isoprostanes. Dietary supplementation with vitamin E normalized (plasma) and reduced (urine) isoprostane levels and, surprisingly, improved proteinuria and blood urea nitrogen (BUN) levels. High ambient glucose increased F(2)-isoprostane synthesis in glomerular endothelial and mesangial cells in culture. Incubation of glomerular cells with F(2)-isoprostanes stimulated the production of TGF-beta.. Increased F(2)-isoprostane synthesis during diabetes appears to be responsible in part for the increase in renal TGF-beta, a well-known mediator of diabetic nephropathy.

Topics: Animals; Cells, Cultured; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Dinoprost; Endothelium; F2-Isoprostanes; Glomerular Mesangium; Glucose; Kidney Glomerulus; Male; Mice; Mice, Inbred Strains; Proteinuria; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta

Cyclosporin is associated with significant chronic nephrotoxicity, manifest in the long term mainly as renal fibrosis. There have been claims that tacrolimus is a less fibrotic drug than cyclosporin, and this study was designed to determine the effect of the two drugs on the expression of fibrosis-associated genes.. Male Wistar rats underwent clamping of the right renal pedicle for 45 min together with left nephrectomy; this model has previously been shown to be associated with upregulation of fibrosis-associated genes. Experimental groups (six animals per group) received cyclosporin A 10 mg/kg daily, tacrolimus 0.2 mg/kg daily or no treatment. Animals were killed at 16 weeks, and the renal cortical expression of fibrosis-associated genes was studied by means of quantitative reverse transcriptase-polymerase chain reaction.. Tacrolimus-treated animals developed significantly less proteinuria and had lower serum creatinine levels than those receiving cyclosporin. Tacrolimus administration also significantly reduced the expression of transforming growth factor beta and tissue inhibitor of metalloproteinases 1, both the products of genes associated with fibrosis. Although cyclosporin treatment reduced levels of the matrix-degrading enzymes, matrix metalloproteinase (MMP) 2 and MMP-9, this was not statistically significant.. Tacrolimus has less nephrotoxicity than cyclosporin in this model. It also appears to have less fibrogenic potential, and this may have implications for the choice of long-term immunosuppressant in renal transplantation.

Topics: Animals; Creatinine; Cyclosporine; Fibrosis; Gene Expression; Immunosuppressive Agents; Kidney Diseases; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Proteinuria; Rats; Rats, Wistar; Renal Artery; Reperfusion Injury; Reverse Transcriptase Polymerase Chain Reaction; Tacrolimus; Transforming Growth Factor beta

Although the renoprotective effect of calcium-channel blockers (CCBs) has been examined in several models of hypertensive nephropathy, it remains unclear. It also remains to be clarified whether CCBs prevent the progression to end-stage renal failure in chronic progressive glomerulonephritis (GN). A new rat model of progressive mesangioproliferative GN was used to study the effect of benidipine hydrochloride, a long-acting dihydropyridine CCB, on the clinical features and morphological lesions.. This animal model of progressive GN was induced by a single intravenous injection of anti-Thy-1 monoclonal antibody (MoAb 1-22-3) two weeks after unilateral nephrectomy. After 10 weeks of treatment with benidipine (1, 3, and 5 mg/kg body weight, p.o.) or hydralazine (5 mg/kg body weight, p.o.), systolic blood pressure (SBP), urinary protein excretion, creatinine clearance, glomerulosclerosis index, tubulointerstitial lesion index, glomerular cross-sectional area, and glomerular expression of transforming growth factor-beta (TGF-beta) and alpha-smooth muscle actin (alpha-SMA) were measured.. Untreated rats developed hypertension, massive proteinuria, renal dysfunction, severe glomerular and tubulointerstitial injury, higher glomerular size, and marked glomerular staining for TGF-beta and alpha-SMA, while uninephrectomized control rats did not. Each dose of benidipine and hydralazine equally reduced SBP to uninephrectomized control levels. Three and five mg/kg/day of benidipine increased creatinine clearance, ameliorated glomerular and tubulointerstitial injury, and reduced glomerular staining for TGF-beta and alpha-SMA, but 1 mg/kg/day of benidipine and hydralazine failed. Only a dose of 5 mg/kg/day of benidipine reduced glomerular size, although it did not reduce the size to control levels.. These results indicate that in a rat model of progressive mesangioproliferative GN, benidipine prevents the progression to end-stage renal failure in a dose-dependent manner. This renoprotective action is associated with the suppression of glomerular expression of TGF-beta and alpha-SMA.

Topics: Actins; Animals; Blood Pressure; Body Weight; Calcium Channel Blockers; Creatinine; Dihydropyridines; Disease Models, Animal; Disease Progression; Fluorescent Antibody Technique; Glomerulonephritis, Membranoproliferative; Hydralazine; Kidney Failure, Chronic; Kidney Glomerulus; Male; Nephrectomy; Proteinuria; Rats; Rats, Wistar; Transforming Growth Factor beta; Vasodilator Agents

RF/J mice were first reported as a murine model of spontaneous glomerulosclerosis by Gude and Lupton in 1960, but the precise histologic characteristics and immunopathological background of this mouse have not been investigated further.. Measurements of serum levels of immunoglobulins, anti-single strand DNA (anti-ss-DNA) antibody, complement (C3), and circulating immune complex (IC) were performed. Analyses of glomerular histological and immunopathological lesions in association with the detection of mRNA expression of collagen IV, TGF-beta, matrix protein turnover related enzymes, matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase-2 (TIMP-2) and platelet-derived growth factor (PDGF) were also performed in young (10-week-old) and elderly (60-week-old) RF/J mice with age-matched BALB/C mice as the controls.. High levels of serum IgA and IgG from as early as 20 weeks of age were noted in the RF/J mice. Serum anti-ss-DNA antibody of aged RF/J mice increased up to 23% of that of aged MRL-lpr/lpr mice, and serum C3 concentration significantly decreased with age, reaching lower levels than that of BALB/c mice. IgA-IC levels were significantly high compared to BALB/C mice both in the early and late stages of life, whereas IgG-IC levels were high only in mice younger than 20 weeks. Semiquantitative and quantitative analyzes of renal histopathological findings revealed significantly marked and age-related mesangial matrix expansion in RF/J mice, with increasing frequency of global glomerular sclerosis and tubulointerstitial damage. On the other hand, although precise measurements of glomerular cell numbers also showed an apparent augmentation in both young and old RF/J mice compared to BALB/C mice, glomerular cellularity decreased with age in RF/J mice. Immunohistochemical study revealed massive immunoglobulin deposition from a young age in association with significantly higher accumulation of matrix proteins, such as types I and IV collagen and laminin from the early stage of life. In addition, in these glomeruli, transforming growth factor-beta1 (TGF-beta1) was highly expressed both in young and old mice. The mRNA expression of MMP-2 was up-regulated only in the early stage of life. Although PDGF mRNA of RF/J mice was significantly up-regulated in the early stage of life, the differences between the mice disappeared in the late stage of life.. These findings suggest that in RF/J mice, an immunopathological background inducing high serum immunoglobulin and IC levels from the early stage of life is closely related to mesangioproliferative glomerular lesions mediated by PDGF, and that development of massive extracellular matrix accumulation in glomeruli was induced by up-regulated expression of TGF-beta with inappropriate regulation of protein turnover-related enzyme production.

Topics: Age Factors; Animals; Antibodies, Antinuclear; Complement System Proteins; Disease Models, Animal; Extracellular Matrix Proteins; Glomerulonephritis; Immune Complex Diseases; Immunoglobulin A; Immunoglobulin G; Kidney Glomerulus; Mice; Mice, Inbred BALB C; Mice, Inbred Strains; Microscopy, Electron; Proteinuria; RNA, Messenger; Transforming Growth Factor beta; Up-Regulation

The renin-angiotensin system is thought to be involved in the progression of glomerulonephritis (GN) into end-stage renal failure (ESRF) because of the observed renoprotective effects of angiotensin-converting enzyme inhibitors (ACEIs). However, ACEIs have pharmacological effects other than ACE inhibition that may help lower blood pressure and preserve glomerular structure. We previously reported a new animal model of progressive glomerulosclerosis induced by a single intravenous injection of an anti-Thy-1 monoclonal antibody, MoAb 1-22-3, in uninephrectomized rats. Using this new model of progressive GN, we examined the hypothesis that ACEIs prevent the progression to ESRF by modulating the effects of angiotensin II (Ang II) on the production of transforming growth factor-beta (TGF-beta) and extracellular matrix components.. We studied the effect of an ACEI (cilazapril) and an Ang II type 1 receptor antagonist (candesartan) on the clinical features and morphological lesions in the rat model previously reported. After 10 weeks of treatment with equihypotensive doses of cilazapril, cilazapril plus Hoe 140 (a bradykinin receptor B2 antagonist), candesartan, and hydralazine, we examined systolic blood pressure, urinary protein excretion, creatinine clearance, the glomerulosclerosis index, and the tubulointerstitial lesion index. We performed a semiquantitative evaluation of glomerular immunostaining for TGF-beta and collagen types I and III by immunofluorescence study and of these cortical mRNA levels by Northern blot analysis.. Untreated rats developed massive proteinuria, renal dysfunction, and severe glomerular and tubulointerstitial injury, whereas uninephrectomized control rats did not. There was a significant increase in the levels of glomerular protein and cortical mRNA for TGF-beta and collagen types I and III in untreated rats. Cilazapril and candesartan prevented massive proteinuria, increased creatinine clearance, and ameliorated glomerular and tubulointerstitial injury. These drugs also reduced levels of glomerular protein and cortical mRNA for TGF-beta and collagen types I and III. Hoe 140 failed to blunt the renoprotective effect of cilazapril. Hydralazine did not exhibit a renoprotective effect.. These results indicate that ACEIs prevent the progression to ESRF by modulating the effects of Ang II via Ang II type 1 receptor on the production of TGF-beta and collagen types I and III, as well as on intrarenal hemodynamics, but not by either increasing bradykinin activity or reducing blood pressure in this rat model of mesangial proliferative GN.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Bradykinin; Bradykinin Receptor Antagonists; Cilazapril; Collagen; Disease Models, Animal; Glomerulonephritis, Membranoproliferative; Hydralazine; Kidney Failure, Chronic; Male; Proteinuria; Rats; Rats, Wistar; Renal Circulation; Renin-Angiotensin System; Tetrazoles; Transforming Growth Factor beta

The present study investigated the pathogenesis and the time course of kidney injury in experimental IgA nephropathy. In order to determine an appropriate period in the course of experimental IgA nephropathy to study renal injury and repair, we examined proteinuria and IgA deposition in the renal mesangium after 4, 8, and 16 weeks of mucosal challenge by bovine gamma globulins (BGG) provided in the drinking water. The hallmark of IgA deposition in the mesangium was present after 4 weeks and 8 weeks of BGG inoculation, but by 16 weeks, the mesangial IgA deposition had resolved. In addition, we confirmed our previous report on the beneficial effects of alpha-tocopherol in reducing proteinuria in IgA nephropathy at 8 weeks, and extended this observation to investigate the effects of dietary supplementation of alpha-tocopherol at both 4 weeks and 16 weeks. Proteinuria resolved spontaneously at 16 weeks. There is oxidative stress, as suggested by the elevation in plasma and renal malondialdehyde content, and increased fibrogenic cytokine message, as suggested by elevated transforming growth factor beta1 mRNA. These increases were clearly blunted by alpha-tocopherol at both 4 weeks and 8 weeks. Treatment with alpha-tocopherol was associated with a significant reduction in the severity of proteinuria. Thus, our data suggest that the period between 4 and 8 weeks of BGG vaccination could be relevant in designing an appropriate model to study the molecular biology of the pathogenesis of renal injury and the effects of treatment. The 16-week model may be useful in exploring gene expression involved with spontaneous resolution.

Topics: Animals; Blotting, Northern; Cattle; Diet; Glomerular Mesangium; Glomerulonephritis, IGA; Immunoglobulin A; Male; Malondialdehyde; Mycobacterium bovis; Oxidative Stress; Proteinuria; Rats; Rats, Inbred Lew; RNA, Messenger; Time Factors; Transforming Growth Factor beta; Vitamin E

Renal hemodynamics and immune responses differ between males and females. Thus, sex hormones and genetically determined gender differences may determine the process of chronic rejection to some extent.. Female (F) or male (M) F344 kidneys were orthotopically transplanted into ovariectomized female Lewis recipients and were treated for 16 weeks with either estradiol, testosterone, or vehicle.. Testosterone treatment resulted in increased urinary protein excretion independently of the donor gender, as well as extended glomerular sclerosis, interstitial fibrosis, and severe vascular lesions. Additionally, mononuclear cell infiltration was most pronounced in these animals, in parallel to an increased expression of intercellular adhesion molecule-1 (ICAM-1), fibronectin, laminin, and transforming growth factor-beta (TGF-beta) in the grafts. Estradiol treatment resulted in an improved graft function, reduced glomerular sclerosis, and a diminished cellular infiltration, in parallel to a reduced ICAM-1, fibronectin, laminin, and TGF-beta expression. In animals treated with vehicle, the gender of the donor influenced the outcome. Grafts of male origin had good graft function and histology, whereas grafts from female donors developed severe proteinuria and glomerular, interstitial, and vascular damage.. These results suggest that a protective effect of estradiol on the progression of chronic rejection exists that is independent of donor gender. Additionally, a male kidney may benefit from the absence of testosterone, whereas the function of a female kidney deteriorates in the absence of estradiol.

Topics: Animals; Antineoplastic Agents, Hormonal; Blood Pressure; Body Weight; Chronic Disease; Estradiol; Female; Gene Expression; Graft Rejection; Insulin-Like Growth Factor I; Kidney Transplantation; Male; Proteinuria; Rats; Rats, Inbred F344; Rats, Inbred Lew; Reverse Transcriptase Polymerase Chain Reaction; Sex Factors; Testosterone; Transforming Growth Factor beta

Oxidative stress occurs in diabetic patients and experimental models of diabetes. We examined whether two antioxidants, melatonin and taurine, can ameliorate diabetic nephropathy. Enhanced expression of glomerular TGF-beta1 and fibronectin mRNAs and proteinuria were employed as indices of diabetic nephropathy. Experimental diabetes was induced by intravenous injection of streptozotocin 50 mg/kg. Two days after streptozotocin, diabetic rats were assigned to one of the following groups: i) untreated; ii) melatonin supplement by 0.02% in drinking water; or iii) taurine supplement by 1% in drinking water. Four weeks after streptozotocin, diabetic rats (n = 6: plasma glucose 516+/-12 mg/dl) exhibited 6.1 fold increase in urinary protein excretion, 1.4 fold increase in glomerular TGF-beta1 mRNA, 1.7 fold increase in glomerular fibronectin mRNA, 2.2 fold increase in plasma lipid peroxides (LPO), and 44 fold increase in urinary LPO excretion above the values in control rats (n = 6: plasma glucose 188+/-14 mg/dl). Chronic administration of melatonin (n = 6) and taurine (n = 6) prevented increases in glomerular TGF-beta1 and fibronectin mRNAs and proteinuria without having effect on blood glucose. Both treatments reduced lipid peroxidation by nearly 50%. The present data demonstrate beneficial effects of melatonin and taurine on early changes in diabetic kidney and suggest that diabetic nephropathy associated with hyperglycemia is largely mediated by oxidative stress.

Topics: Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Diuresis; Fibronectins; Gene Expression Regulation; Kidney Glomerulus; Lipid Peroxidation; Male; Melatonin; Oxidative Stress; Proteinuria; Rats; Rats, Sprague-Dawley; RNA, Messenger; Taurine; Transcription, Genetic; Transforming Growth Factor beta

A spontaneously hypercholesterolemic Imai rat has recently been reported as a model of focal glomerulosclerosis that causes nephrotic syndrome followed by renal failure. This study was designed to determine if an oral adsorbent, AST-120, ameliorates renal lesions and TGF-beta 1 expression in the rats.. AST-120 was given orally to the Imai rats for 32 weeks, and renal function and pathology were compared between the AST-120-administered and control Imai rats.. AST-120-administered rats showed significantly lower level of blood urea nitrogen, serum creatinine, urinary protein, serum total-cholesterol, serum triglyceride, and serum and urinary indoxyl sulfate, and significantly higher levels of serum albumin and creatinine clearance than control rats. AST-120 reduced the glomerular sclerosis index, interstitial fibrosis area, and the extent of glomerular lipid deposition. Immunohistochemistry demonstrated that AST-120 reduced the expression of transforming growth factor (TGF)-beta 1 and tissue inhibitor of metalloproteinase (TIMP)-1 as well as interstitial infiltration of macrophages in the renal cortex of the Imai rats.. AST-120 prevented the progression of nephrotic syndrome and renal failure in the Imai rats by ameliorating glomerular sclerosis and interstitial fibrosis, accompanied with reduced expression of TGF-beta 1 and TIMP-1, and reduced infiltration of macrophages in the kidneys.

Topics: Administration, Oral; Animals; Blood Urea Nitrogen; Carbon; Cholesterol; Creatinine; Hypercholesterolemia; Immunohistochemistry; Kidney; Kidney Glomerulus; Male; Oxides; Proteinuria; Rats; Transforming Growth Factor beta; Triglycerides

Angiotensin-converting enzyme inhibitors exert a beneficial effect on nephritis. We investigated the effects of KD3-671, an angiotensin AT1 receptor antagonist (2-propyl-8-oxo-1-[(2'-(H-tetrazole-5-yl)biphenyl-4-yl)methyl]-4,5,6,7-t etrahydro-cycloheptimidazole), on anti-glomerular basement membrane antibody-associated nephritis in rats. Untreated nephritic rats had massive proteinuria, glomerular lesions including crescent formation, a significant augmentation of proliferating cell nuclear antigen-positive cells, alpha-smooth muscle actin-positive cells, and the increase in deposition of proteoglycan, fibronectin and desmin in the glomeruli. Administration of KD3-671 to nephritic rats prevented the development of intense proteinuria, glomerular alterations and the increase in plasma urea nitrogen. KD3-671 suppressed the deposition of matrix protein and the expression of alpha-smooth muscle actin and desmin in the nephritic glomeruli. Captopril, an angiotensin-converting enzyme inhibitor, suppressed urinary protein excretion and the expression of desmin in the nephritic glomeruli, but not other parameters. These results suggest that KD3-671 may be a useful medicine against glomerulonephritis and glomerulosclerosis.

Topics: Angiotensin Receptor Antagonists; Animals; Extracellular Matrix Proteins; Glomerulonephritis; Imidazoles; Immunoglobulin G; Kidney Glomerulus; Male; Proteinuria; Rats; Rats, Sprague-Dawley; Tetrazoles; Transforming Growth Factor beta

Inhibition of the renin-angiotensin system by both angiotensin II type 1 receptor antagonists (AT1As) and angiotensin I-converting enzyme inhibitors (ACEIs) shows renoprotective effects in rats with chronic renal failure when treatment is started in the early phase of renal injury. In this study, we examined the renal protective effects of candesartan cilexetil (TCV-116), an AT1A, and enalapril, an ACEI, in the progressive phase of renal injury in 5/6 nephrectomized rats.. Candesartan cilexetil (1 mg/kg/day) and enalapril (10 mg/kg/day) were orally administered once a day for 4 weeks (the short-term experiment) or 16 weeks (the long-term experiment) to 5/6 nephrectomized rats beginning 15 weeks after the nephrectomy, that is, after they had already showed marked proteinuria.. In vehicle-treated rats, proteinuria, glomerulosclerosis, and interstitial fibrosis developed. Moreover, enhanced expression of transforming growth factor-beta1 (TGF-beta1) in the injured glomeruli was observed. These adverse changes progressed with time, and in the short-term experiment, both drugs inhibited them. In the long-term experiment, the progressive proteinuria and the elevation of blood pressure were similarly attenuated by both drugs. However, candesartan cilexetil significantly inhibited the progression of glomerulosclerosis, the expression of TGF-beta1, and interstitial fibrosis, whereas enalapril did not.. These results indicate that candesartan cilexetil shows potent and long-term preventive effects against the progression of previously developed renal injury.

Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Blood Urea Nitrogen; Creatinine; Dinoprostone; Disease Models, Animal; Enalapril; Kidney Failure, Chronic; Male; Nephrectomy; Proteinuria; Rats; Rats, Sprague-Dawley; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Renin; Tetrazoles; Transforming Growth Factor beta

Resident glomerular cell proliferation, matrix deposition and secretion of matrix metalloproteinases play a major role in the progression of chronic glomerular disease. These features were studied in a novel approach in a rat model of chronic glomerulonephritis induced by four injections of an anti-Thy 1.1 antiserum at weekly intervals.. Chronic immune mediated mesangial injury was induced in male Sprague-Dawley rats by repeated intravenous injection of an anti-Thy 1.1 antiserum. One week after the first and fourth injection of the antiserum proteinuria was evaluated and the kidneys were removed. Immunohistology was performed for proliferating cells, monocytes and collagen type IV. Furthermore, mRNA expression of collagen type IV, TGF-beta and the matrix degrading enzyme MMP-2 as well as MMP-2 protein expression were studied.. Urinary protein excretion was dramatically increased after one antiserum injection and stayed elevated at a lower level after the fourth antiserum injection. After the initial induction of nephritis, 7 days following antiserum, resident glomerular cell proliferation was increased whereas with repeated injections of the antiserum cell numbers were not different from controls, as measured 1 week after the fourth injection. In contrast, extracellular matrix accumulation (collagen type IV) increased after the first antiserum injection and further increased after the fourth antiserum injection. The mRNA expression for collagen type IV increased after the first antiserum injection and showed further increase after the fourth antiserum injection. Induction of nephritis also stimulated glomerular mRNA expression of MMP-2 and TGF-beta, both of which remained at a high level after the fourth antiserum injection. Glomerular protein levels of MMP-2 also increased after the first antiserum injection and showed a further slight increase after the fourth injection.. Increased cellular proliferation is involved in an early stage of this disease, while enhanced expression of glomerular matrix and augmented mRNA and protein expression of the matrix degrading enzyme MMP-2 continue into the chronic phase, and contribute to the extensive structural remodeling process that accompanies this form of glomerular injury.

Topics: Animals; Cell Division; Chronic Disease; Collagen; Extracellular Matrix Proteins; Glomerulonephritis; Kidney; Male; Matrix Metalloproteinase 2; Proteinuria; Rats; Rats, Sprague-Dawley; RNA, Messenger; Transforming Growth Factor beta

Diabetic nephropathy is characterized by glomerular hypertrophy. We have recently shown that experimental diabetes mellitus is associated with an increase in glomerular expression of the cyclin kinase inhibitor p21WAF1/CIP1 (p21). Furthermore, in vitro glucose-induced mesangial cell hypertrophy is also associated with an up-regulated expression of p21. In this study, we tested the hypothesis that p21 mediates diabetic glomerular hypertrophy in vivo.. Experimental diabetes mellitus was induced by streptozotocin in mice in which p21 was genetically deleted (p21 -/-) and in wild-type mice (p21 +/+). Kidney biopsies were obtained from diabetic and control (citrate injected) p21 +/+ and p21 -/- mice at day 60. The tissue was used for morphologic studies of glomerular size (measured by computer image-analysis system), glomerular cellularity (cell count), glomerular matrix expansion (silver stain), apoptosis (TUNEL), and expression of transforming growth factor-beta1 (TGF-beta1) by in situ hybridization.. The glomerular tuft area increased 11.21% in diabetic p21 +/+ mice at day 60 compared with control (3329.98 +/- 244.05 micrometer(2) vs. 2994. 39 +/- 176.22 micrometer(2), P = 0.03), and the glomerular cell count did not change in diabetic p21 +/+ mice at day 60 compared with the control. These findings are consistent with glomerular hypertrophy. In contrast, the glomerular tuft area did not increase in diabetic p21 -/- mice at day 60 compared with the control (3544.15 +/- 826.49 vs. 3449.15 +/- 109.65, P = 0.82), nor was there an increase in glomerular cell count (41.41 +/- 13.18 vs. 46.95 +/- 3.00, P = 0.43). Diabetic p21 +/+ mice, but not p21 -/- mice, developed an increase in proteinuria at day 60 compared with the control. Tubular cell proliferation, measured by proliferating cell nuclear antigen immunostaining, was increased in both diabetic p21 +/+ (2.1-fold) and p21 -/- (7.61-fold) mice compared with controls. Glomerular cell apoptosis did not increase in diabetic mice. Although glomerular TGF-beta1 mRNA levels increased in both strains of diabetic mice at day 60, the glomerular matrix did not expand.. Hyperglycemia was associated with glomerular hypertrophy in p21 +/+ mice. Despite the increase in TGF-beta1 mRNA, diabetic p21 -/- mice did not develop glomerular hypertrophy, providing evidence that the cyclin kinase inhibitor p21 may be required for diabetic glomerular hypertrophy induced by TGF-beta1. The loss of p21 increases tubular but not glomerular cell proliferation in diabetic nephropathy. The absence of glomerular hypertrophy appears protective of renal function in diabetic mice.

Topics: Animals; Blood Glucose; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Diabetes Mellitus, Experimental; Diabetic Nephropathies; DNA; Hypertrophy; Kidney Glomerulus; Kidney Tubules; Mice; Mice, Knockout; Proteinuria; RNA, Messenger; Streptozocin; Transforming Growth Factor beta

It has been demonstrated that intraperitoneal administration of proteolytic enzymes ameliorates the progression of renal diseases in various animal models. In the present study, we employed the rat remnant kidney model to study the effectiveness of oral administration of proteases. Twenty male Wistar rats underwent sham operation (CTRL), while 25 were subjected to 5/6 nephrectomy (5/6 NX). Rats were randomised into placebo (PL) (2 ml tap water/day by gavage), or Phlogenzym (E; fixed mixture of trypsin 2.42 mg, bromelain 4.54 mg, and rutozid 5.04 mg added as antioxidant, in 2 ml tap water daily by gavage) treated group. Duration of the study was 45 days. Rats were pair-fed. Enzyme treatment exerted salutary effects on various functional and morphological parameters. Proteinuria was higher in both 5/6 NX group rats throughout the study. Administration of proteases ameliorated its rise effectively (data at sacrifice: CTRL-PL 6.27 +/- 1.25, CTRL-E 9.27 +/- 0.99, 5/6 NX-PL 74.04 +/- 21.33, 5/6 NX-E 39.09 +/- 7.93 mg/24 h; P < 0.01). Increased urinary excretion of the fibrogenic cytokine transforming growth factor (TGF-beta 1) was improved, too (CTRL-PL 0.349 +/- 0.051, CTRL-E 0.693 +/- 0.230, 5/6 NX-PL 3.044 +/- 0.540, 5/6 NX-E 1.390 +/- 0.238 ng/mumol creatinine; P < 0.05). At sacrifice, tubulointerstitial fibrosis was less pronounced in E-treated rats. Correspondingly, the volume fraction of tubulointerstitial tissue in the renal cortex was improved in 5/6 NX-E rats (CTRL-PL 9.9 +/- 0.2, CTRL-E 10.0 +/- 0.2, 5/6 NX-PL 17.9 +/- 1.8, 5/6 NX-E 13.8 +/- 0.9%; P < 0.05). The protein/DNA ratio in isolated glomeruli and tubules, as an estimate of glomerular matrix accumulation and hypertrophy of tubules, was enhanced in 5/6 NX groups and a tendency towards lower values was observed after E treatment. Renal function as evaluated by serum creatinine and urea levels was not influenced by the enzyme therapy. No between-group differences in blood pressure were observed. In summary, oral administration of proteolytic enzymes improved proteinuria and urinary TGF-beta 1 excretion, as well as the severity of tubulointerstitial fibrosis without signs of toxicity.

Topics: Administration, Oral; Animals; Disease Models, Animal; DNA; Endopeptidases; Fibrosis; Kidney Diseases; Male; Nephrectomy; Proteins; Proteinuria; Rats; Rats, Wistar; Transforming Growth Factor beta

We evaluated the effect of blocking angiotensin II (AngII) on the development of proteinuria and glomerular injury in antithymocyte serum (ATS) glomerulonephritis. Disease was induced in Sprague-Dawley rats by a single intravenous injection of rabbit ATS. Three groups of rats were considered: group 1 (n = 13), ATS rats with no therapy; group 2 (n = 13), ATS rats treated with angiotensin-converting enzyme inhibitor (40 mg/L lisinopril in the drinking water); and group 3 (n = 13), ATS rats treated with AngII receptor antagonist (50 mg/L L-158,809 in the drinking water). Treatment started 3 hours after ATS injection and lasted 4 days. An additional group of control rats (group 4, n = 13) received preimmune serum. At day 4, ATS rats developed proteinuria (46+/-5 mg/d v control 12+/-1 mg/d; P < 0.01), which was prevented by both lisinopril and L-158,809 (14+/-0.2 mg/d and 15+/-1.6 mg/d, respectively, P < 0.01 v ATS). Systolic blood pressure was comparable in ATS rats and in controls (119+/-4 mm Hg v 120+/-2 mm Hg). Systolic blood pressure values were significantly decreased after either lisinopril or L-158,809 (104+/-3 mm Hg and 101+/-5 mm Hg, respectively; P < 0.01 v ATS). Serum creatinine levels were similar in all groups. Quantitation of proliferating cells and macrophages by analysis of proliferating cell nuclear antigen-positive and ED1-positive cells/glomerular cross-section showed a marked increase in proliferating cell nuclear antigen-positive cells in glomeruli of ATS rats over controls (12.6+/-0.5 cells/glomerular cross-section v 1.9+/-0.2 cells/glomerular cross-section; P < 0.01), which was significantly (P < 0.01) prevented by both treatments (lisinopril, 5.7+/-1.0 cells/glomerular cross-section; L-158,809, 4.8+/-1.5 cells/glomerular cross-section). The increase in ED1-positive cells (10+/-0.7 cells/glomerular cross-section v controls, 1.8+/-0.2 cells/glomerular cross-section; P < 0.01) was also significantly (P < 0.01) reduced by lisinopril and L-158,809 (4.1+/-0.7 cells/glomerular cross-sections and 2.6+/-0.6 cells/glomerular cross-section, respectively). Blocking of AngII activity prevented almost completely the formation of microaneurysms in ATS rats (percent of glomeruli with microaneurysms: ATS, 11.5%+/-3.5%; ATS + lisinopril, 0.4%+/-0.2%; ATS + L-158,809, 0.8%+/-0.8%; controls, 0%). Because AngII is a potent inducer of renal transforming growth factor-beta (TGF-beta), a cytokine involved in the regulation of cell proliferation, matrix deposi

Topics: Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Animals; Antilymphocyte Serum; Blood Pressure; Cell Division; Creatinine; Glomerulonephritis, Membranoproliferative; Immunoglobulin G; Kidney; Kidney Glomerulus; Lisinopril; Macrophages; Male; Monocytes; Proteinuria; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta

The present two studies were designed to determine whether oxidized LDL contributes to the tubulointerstitial changes seen in rats during the acute phase of acute puromycin aminonucleoside nephrosis (PAN). In the single-dose study, rats were given one injection of puromycin aminonucleoside (PA; 15 mg/100 g body wt) and killed 1, 2, or 3 wk thereafter. The four animal groups were saline controls, PAN controls, PAN plus probucol, and PAN plus lovastatin. This study showed that the addition of probucol significantly reduced the mean levels of serum cholesterol and renal lipid-peroxidation products, an effect not seen with lovastatin therapy. Compared with saline controls, PAN controls had a significant increase in total kidney collagen (7.9 +/- 1.2 versus 5.9 +/- 0.6 mg/kidney at 3 wk). Neither probucol nor lovastatin therapy attenuated the interstitial inflammation or fibrosis. In the multidose study, rats were given the same initial PA dose and were uninephrectomized on day 12. They were killed on day 35 after two smaller PA doses were given on days 16 and 23. Animal groups were saline controls, PAN controls, PAN plus probucol, and PAN plus vitamin E. Hepatic lipid-peroxidation products were significantly lower in the probucol-treated, but not in the vitamin E-treated, PAN groups when compared with the PAN controls. Neither probucol nor vitamin E prevented the increase in total kidney collagen that was observed in the PAN control group (7.4 +/- 0.7, 10.1 +/- 2.6, and 9.3 +/- 1.8 mg of collagen/kidney, respectively, versus 5.4 +/- 0.5 mg/kidney for the saline controls). Renal cortical mRNA levels for matrix-encoding genes and protease inhibitors were similar in the three nephrotic groups. Transforming growth factor-beta1 mRNA levels were highly variable within each group and not significantly different at day 35, but showed a significant positive correlation with the degree of albuminuria (r = 0.70). The present results demonstrate that the treatment of acutely nephrotic rats with antioxidant therapy did not attenuate interstitial inflammation or fibrosis. We speculate that other factors, possibly a consequence of proteinuria itself, are the predominant pathogenetic mediators of the tubulointerstitial damage in acute nephrotic syndrome.

Topics: Animals; Anticholesteremic Agents; Antioxidants; Cholesterol; Collagen; Female; Fibronectins; Fibrosis; Kidney; Lipid Peroxides; Lipoproteins, LDL; Liver; Lovastatin; Macrophages; Microscopy, Fluorescence; Nephrotic Syndrome; Organ Size; Probucol; Proteinuria; Puromycin Aminonucleoside; Rats; Rats, Sprague-Dawley; Time Factors; Transforming Growth Factor beta; Treatment Failure; Vitamin E

In the kidney, aging is characterized by the development of structural changes, including glomerulosclerosis and interstitial fibrosis. Transforming growth factor-beta1 (TGF-beta1) is known to play a critical role in the genesis of these alterations in pathologic conditions. The present experiments were designed to test the hypothesis that TGF-beta1 may be involved in the development of age-related histopathologic changes in rat kidney, and that captopril, an angiotensin-converting enzyme inhibitor, may influence the progression of glomerular and interstitial lesions. In this study, 3-, 18-, 24-, and 30-mo-old rats were examined, and an age-related increase in urinary protein excretion was found; plasma creatinine and systolic BP did not change. Significant structural changes, including glomerular sclerosis and interstitial fibrosis, were found in the group of aged rats (24- and 30-mo-old). Immunostaining for TGF-beta in the renal cortex interstitium was increased in the group of 24-mo-old rats, with a parallel increase in TGF-beta1 mRNA expression, measured with reverse-transcription PCR. Captopril-treated animals showed a statistically significant decrease in urinary protein excretion but no significant changes in BP. Moreover, captopril reduced the extent of interstitial fibrosis, but did not affect the degree of glomerulosclerosis. A significant inhibition of TGF-beta1 mRNA expression was observed in the captopril-treated animals. These findings suggest that TGF-beta1 may act as a fibrogenic growth factor that could be responsible, at least partially, for the renal interstitial fibrosis associated with aging. Treatment with captopril might delay the progression of these lesions.

Topics: Aging; Angiotensin-Converting Enzyme Inhibitors; Animals; Captopril; Immunohistochemistry; Kidney; Kidney Cortex; Kidney Glomerulus; Male; Polymerase Chain Reaction; Proteinuria; Rats; Rats, Wistar; RNA, Messenger; Transcription, Genetic; Transforming Growth Factor beta

Oxidative stress and the fibrogenic cytokine transforming growth factor beta 1 (TGF beta 1) have been implicated in the pathogenesis and progression of IgA nephropathy. In the present study, we used alpha-tocopherol as a dietary supplement to test the hypothesis that the proteinuria, oxidative stress, and TGF beta mRNA can be more effectively lowered with higher doses of alpha-tocopherol. Hematuria, proteinuria, and mesangial IgA deposition are parameters which characterize IgA nephropathy. IgA nephropathy was induced by bovine gamma globulin oral immunization in rats during an 8-week course, and all hallmarks of IgA nephropathy were produced in this 8-week animal model. The elevation in renal malondialdehyde content and TGF beta 1 mRNA, as well as the severity of proteinuria, was blunted by alpha-tocopherol. Our data suggested that conventional dosage of alpha-tocopherol at 100 IU/kg chow lowered kidney TGF beta 1 to control values and increasing the dose by 2 1/2-fold or even 5-fold resulted in no further reduction in TGF beta 1 mRNA. Significant reduction of proteinuria was achieved better with a dose of 250 IU/kg chow of alpha-tocopherol supplementation than with the 100 IU/kg chow. We conclude that alpha-tocopherol at this dose is efficacious in controlling proteinuria, downregulating TGF beta 1, and reducing oxidative stress in experimental IgA nephropathy. Doubling this dose achieved no further benefits.

Topics: Animals; Blotting, Northern; Diet; Disease Models, Animal; Dose-Response Relationship, Drug; Glomerulonephritis, IGA; Male; Malondialdehyde; Oxidative Stress; Proteinuria; Rats; Rats, Inbred Lew; RNA, Messenger; Transforming Growth Factor beta; Vitamin E; Weight Gain

Evidence suggests that transforming growth factor beta 1 (TGF-beta 1), a multifunctional cytokine, induces renal extracellular matrix production and glomerular hypertrophy. The aim of the present study was to investigate the effect of captopril on the expression of TGF-beta 1 mRNA in a rat model of chronic renal failure: five-sixths nephrectomy. Chronic renal disease was induced by removal of the right kidney and ligation of three blood vessels supplying the left kidney. Sham-operated animals were used as controls. RNA was extracted from the viable remnant kidney of rats 1 day and 1 and 2 weeks following five-sixths nephrectomy and from the kidneys of rats who underwent sham surgery. TGF-beta 1 mRNA was induced within 24 h of partial nephrectomy, similar to that reported for early-onset genes. Subsequently, TGF-beta 1 mRNA expression continued to increase over the next 2-4 weeks. The upregulation of TGF-beta 1 correlated with the degree of proteinuria. Both the increase in TGF-beta 1 mRNA and proteinuria were abrogated by captopril treatment. In addition, no change in expression of ALK-5 or type II TGF-beta receptors following five-sixths nephrectomy was observed. These data suggest that captopril may protect against development of glomerulosclerosis and proteinuria by reducing TGF-beta 1 expression and hence matrix production.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Blotting, Northern; Captopril; Disease Models, Animal; Gene Expression; Kidney; Kidney Cortex; Kidney Failure, Chronic; Nephrectomy; Peptidyl-Dipeptidase A; Proteinuria; Rats; Receptors, Transforming Growth Factor beta; RNA, Messenger; Transforming Growth Factor beta

Transgenic mice (T26) bearing the envelope, regulatory, and accessory genes of HIV- I develop renal disease resembling human HIV-associated nephropathy (HIVAN). Effects of vehicle (VEH) and the angiotensin-converting enzyme inhibitor captopril (CAP) were examined in wild-type (WT) or T26 mice treated from 7 to 100 d of age. Mortality was lower in CAP T26 mice (30 mg/kg: 8%; 100 mg/kg: 12%) than VEH T26 mice (52%). The urinary protein/creatinine ratio was increased in VEH T26 mice (19.5+/-7.60) versus WT mice (6.1+/-0.83), but not in low-dose (7.3+/-0.94) or high-dose (8.2+/-1.02) CAP T26 mice. Blood urea nitrogen was higher in VEH T26 mice (52+/-16.2 mg/dl) than VEH WT mice (24+/-0.8). Blood urea nitrogen was also elevated in CAP WT (high dose: 43+/-2.1 mg/dl) and T26 mice (high dose: 42+/-2.4 mg/dl). Glomerular injury was higher in VEH T26 mice (6.8+/-0.58) than VEH WT mice (0.2+/-0.08) or CAP T26 mice (low dose: 1.1+/-0.17; high dose: 0.7+/-0.13). Tubulointerstitial injury was also greater in VEH T26 mice (1.1+/-0.10) than VEH WT mice (0.2+/-0.08) or CAP T26 mice (low dose: 0.4+/-0.10; high dose: 0.3+/-0.10). These data validate recent nonrandomized studies of captopril in HIV-infected patients, and suggest that an angiotensin-converting enzyme substrate is an important mediator in HIVAN. A randomized placebo-controlled trial of captopril in HIVAN may be warranted.

Topics: AIDS-Associated Nephropathy; Angiotensin-Converting Enzyme Inhibitors; Animals; Captopril; Disease Models, Animal; Female; Gene Expression; Genes, Viral; HIV-1; Humans; Kidney; Male; Mice; Mice, Transgenic; Proteinuria; RNA, Messenger; Transforming Growth Factor beta

Multiple injections with a mouse monoclonal anti-rat Thy-1 antibody (five times, at weekly intervals) induced marked glomerular sclerotic lesions which are characterized by adhesion of glomerular capillaries to Bowman's capsule and persistent proteinuria in rats. Abnormal production of type I collagen and increased accumulation of type IV collagen and fibronectin were observed in these glomeruli. The glomerular expression of mRNA for these matrix components and transforming growth factor-beta1 (TGF-beta1) were markedly increased at 4 days after the last injections with anti-Thy-1 antibody, but decreased to below the levels of control rats at 5 weeks. This may be down-regulation of mRNA in mesangial cells. The glomerular sclerotic lesions were not progressive but the process of glomerular healing seemed to be retarded. The proteinuria and the glomerular adhesion were irreversible.

Topics: Animals; Antibodies, Monoclonal; Blood Urea Nitrogen; Collagen; Extracellular Matrix; Fibronectins; Fluorescent Antibody Technique, Indirect; Glomerular Mesangium; Glomerulonephritis, Membranoproliferative; Injections; Isoantibodies; Male; Mice; Mice, Inbred BALB C; Proteinuria; Rats; Rats, Inbred WKY; RNA, Messenger; Transforming Growth Factor beta

Over-expression of iNOS is implicated in the pathogenesis of glomerulonephritis in animal models of systemic lupus erythematosus. The aim of this study was to evaluate the effect of aminoguanidine, a selective inhibitor of iNOS, for the protection from glomerulosclerosis in NZB/W F1 mice. Female NZB/W F1 mice (n = 8) were treated with aminoguanidine (1 g/l) in drinking water for 4 months starting at age 2 months before the onset of glomerulonephritis. Controls were age- and sex-matched mice (n = 10) without aminoguanidine treatment. By glomerular microdissection and reverse-transcription competitive polymerase chain reaction, we found that glomerular iNOS/beta-actin and TGF-beta1/beta-actin mRNA ratios were reduced 15.1% (P<0.05) and 61.3% (P<0.01), respectively, in aminoguanidine-treated mice. Aminoguanidine significantly reduced the glomerular iNOS staining, urinary nitrite production and degree of glomerulosclerosis. In addition, the glomerular volume and mean glomerular cell number were reduced 33.2% (P<0.01) and 32.8% (P<0.01), respectively. Likewise, the urinary proteinuria was also significantly reduced by aminoguanidine. These results indicate that administration of aminoguanidine may reduce the progression of glomerulosclerosis in NZB/W F1 mice, possibly through inhibition of glomerular nitric oxide production.

Topics: Animals; Body Weight; Cell Count; Creatine; Crosses, Genetic; Enzyme Inhibitors; Female; Guanidines; Hypertrophy; Kidney Glomerulus; Lupus Nephritis; Male; Mice; Mice, Inbred NZB; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Nitrites; Organ Size; Proteinuria; RNA, Messenger; Transforming Growth Factor beta

MRL/lpr mice suffer from a systemic lupus erythematosus-like autoimmune disease. We studied the effects of oral treatments with Ninjin-youei-to (NYT, Ren-shen-yang-rong-tang, 1000 mg/kg/day), a suboptimal dose (2 mg/kg/day) of prednisolone(PSL) and their combination on nephritis in MRL/lpr mice. Treatments with NYT or PSL alone inhibited the development of proteinuria and prolonged survival. The combined treatment reduced the incidence of proteinuria and prolonged survival. In histological analysis, NYT treatments decreased the degree of mesangial proliferative glomerulonephritis and infiltration of mononuclear cells in the kidneys. PSL treatment was effective in reducing periglomerular nephritis and vasculitis in addition to such effects as NYT and NYT plus PSL treatment was more effective than PSL alone. The active form of TGF-beta was reduced in NYT and PSL-treated mouse serum, and the combined treatments further suppressed it. However, the treatment with NYT alone did not induce a decrease in the latent form of TGF-beta. The effect of NYT can be assumed to be different from an immunosuppressive effect of PSL. Therefore, the combined treatment with NYT and PSL can be expected to be more useful for the therapy of autoimmune disease such as nephritis, compared with NYT or PSL alone treatments.

Topics: Animals; Anti-Inflammatory Agents; Antigen-Antibody Complex; Autoimmune Diseases; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Female; Kidney; Mice; Mice, Inbred C3H; Mice, Inbred MRL lpr; Nephritis; Prednisolone; Proteinuria; Transforming Growth Factor beta

To elucidate the contribution of the renin-angiontensin system (RAS) to glomerular injury in salt-sensitive hypertension, we investigated the chronic effects of the angiotensin I-converting enzyme inhibitor cilazapril and the angiotensin II type 1-receptor antagonist (AT1a) TCV-116 in Dahl-Iwai rats. Dahl salt-sensitive (S) rats receiving 8% salt diet for 6 wk were simultaneously treated with cilazapril (n = 6), TCV-116 (n = 6), or saline (n = 14). The 8% salt diet markedly increased systolic blood pressure (SBP), urinary protein, and N-acetyl-beta-glucosaminidase (NAG) excretion compared with 0.3% salt-treated S (n = 6) or salt-resistant (n = 6) rats. Although neither cilazapril nor TCV-116 reduced the elevated SBP, TCV-116 significantly lowered urinary protein and NAG excretion. Histologically, 8% salt treatment in S rats induced progressive sclerotic and proliferative glomerular changes, which were ameliorated by both drugs. TCV-116 increased the glomerular diameter. Immunofluorescence demonstrated the increased level of type III collagen in the mesangium of 8% salt-treated S rats, which was completely reversed by TCV-116. Competitive RT-PCR of mRNA extracted from the glomeruli revealed that 8% salt treatment significantly increased the levels of proliferating cell nuclear antigen (PCNA) and platelet-derived growth factor B-chain and that TCV-116 significantly reduced the levels of PCNA and transforming growth factor-beta1 (TGF-beta1). Thus, although the chronic RAS-inhibition in salt-sensitive hypertension exerted a histologically renoprotective effect by both ways without lowering blood pressure, the RAS inhibition due to AT1a had more beneficial advantages of reducing proteinuria and attenuating the levels of glomerular TGF-beta1 and extracellular matrix.

Topics: Acetylglucosaminidase; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Body Weight; Cilazapril; Creatinine; Heart Rate; Kidney Glomerulus; Platelet-Derived Growth Factor; Proliferating Cell Nuclear Antigen; Proteinuria; Rats; Rats, Inbred Dahl; Sclerosis; Tetrazoles; Transforming Growth Factor beta; Urine

In several models of renal disease progression, angiotensin-converting enzyme (ACE) inhibitors reduced proteinuria and limited glomerulosclerosis, which suggested that reduction of renal angiotensin II (Ang II) activity is crucial for the preservation of glomerular structure and function. However, it cannot be ruled out that other hormonal systems, including inhibition of the bradykinin breakdown, also play a role. We compared the effects of chronic treatment with the ACE inhibitor lisinopril with those of a specific Ang II receptor antagonist, L-158,809, on proteinuria and renal injury in passive Heymann nephritis (PHN), a model of immune renal disease that closely resembles human membranous nephropathy, with long-lasting proteinuria followed by tubulointerstitial damage and glomerulosclerosis. Passive Heymann nephritis was induced with 0.5 mL/100 g of rabbit anti-Fx1A antibody in 24 male Sprague-Dawley rats. The animals were divided into three groups of eight rats each, and were given the following in the drinking water on a daily basis: lisinopril (40 mg/L), L-158,809 (50 mg/L), or no therapy. Treatment started at day 7 (proteinuria was already present) and lasted 12 months. Eight normal rats were used as controls. Untreated PHN rats developed hypertension, while rats with PHN given lisinopril or L-158,809 all had systolic blood pressure values even lower than those of normal rats. Urinary protein excretion progressively increased with time in untreated PHN rats, who developed tubulointerstitial damage and glomerulosclerosis. Both lisinopril and L-158,809 exhibited a potent antiproteinuric effect and preserved glomerular and tubular structural integrity at a similar extent. Renal gene expression of transforming growth factor-beta and extracellular matrix proteins was also effectively reduced by the two treatments. These results indicate that ACE inhibitors and Ang II receptor antagonists are equally effective in preventing renal injury in PHN and suggest that the renoprotective effects of ACE inhibitors in this model are solely due to inhibition of Ang II.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Pressure; Chronic Disease; Extracellular Matrix Proteins; Glomerular Filtration Rate; Glomerulonephritis, Membranous; Imidazoles; Kidney; Lisinopril; Male; Proteinuria; Rats; Rats, Sprague-Dawley; Renal Plasma Flow; Tetrazoles; Transforming Growth Factor beta

Collagen cross-linking induced by lysyl oxidase has been implicated in liver and lung fibrosis. To define the role of this process in kidney fibrosis, we investigated the renal expression of lysyl oxidase and the content in collagen cross-links at various stages of chronic Adriamycin nephropathy in Sprague-Dawley rats. Lysyl oxidase expression was determined by RT-PCR; collagen pyridinium residues, indicating lysyl oxidase induced cross-links, were evaluated by HPLC. These parameters followed a synergic albeit asynchronous outcome: (a) lysyl oxidase mRNA levels in total kidney, glomeruli and medulla from Adriamycin-treated rats increased up to 3 times compared to controls between week 8 and 12, then returning within the normal range; (b) the pyridinium residue content did not show any significant difference between Adriamycin-treated and control rats, until diffuse interstitial fibrosis developed (16 weeks), showing at this time a 2- to 3-fold increment. Lysyl oxidase was expressed by several renal cell lines and in tubular-epithelial cells it was up-regulated in vitro by TGF beta-1, a recognized fibrogenetic factor in Adriamycin nephropathy. Our observations demonstrated that an increased expression of lysyl oxidase in the kidney precedes the development of diffuse fibrotic lesions and that, at this stage, collagenic structures contain highly cross-linked components, the final product of lysyl oxidase activity. The evidence of lysyl oxidase up-regulation in tubular epithelial cells by the same factor implicated in Adriamycin toxicity in the kidney suggests a common pathogenetic mechanism. Collagen cross-link formation by lysyl oxidase may be implicated in the pathogenesis of irreversible, fibrotic renal lesions.

Topics: Animals; Becaplermin; Collagen; Doxorubicin; Fibrosis; Kidney; Kidney Cortex; Kidney Glomerulus; Kinetics; Male; Platelet-Derived Growth Factor; Polymerase Chain Reaction; Protein-Lysine 6-Oxidase; Proteinuria; Proto-Oncogene Proteins c-sis; Pyridinium Compounds; Rats; Rats, Sprague-Dawley; RNA, Messenger; Transcription, Genetic; Transforming Growth Factor beta

In this study, we investigated 1) whether long-term restoration of euglycemia by means of pancreatic islet transplants is capable of preventing and/or reversing renal functional and structural alterations in an experimental model of insulin-deficient diabetes, and 2) whether changes in extracellular matrix (ECM) and cell turnover at the glomerular level and biochemical abnormalities associated with hyperglycemia correlate with the renal outcome after transplantation. Male Lewis rats, rendered diabetic by intravenous injection of streptozotocin, underwent homologous islet transplantation via the portal vein at 2 weeks (study A), at 4 months (study B), and at 8 months (study C) after the induction of diabetes and killed 12 months after transplantation in study A and 4 months after transplantation in studies B and C. Age-matched nondiabetic and untreated diabetic rats were used as control animals and were studied at 4, 8, and 12 months. In the untreated diabetic animals, metabolic derangement was associated with increased erythrocyte polyol and fructose levels, tail-tendon content of advanced glycation end products (AGEs), total proteinuria, albuminuria, kidney weight, and mean glomerular volume as well as with marked glomerular and extraglomerular lesions. Glomerular gene expression for the ECM components fibronectin and collagen IV and for TGF-beta was also increased, whereas glomerular cell proliferation was unaffected by diabetes. In study A, changes in renal function and structure observed in diabetic rats at 12 months were completely prevented by successful islet transplants. In study B, all functional and structural abnormalities detected in diabetic rats at 4 months of disease duration were virtually reversed by 4 months of euglycemia in transplanted animals, whereas they progressed further in untreated diabetic rats. In study C, the course of functional and structural changes observed in untreated diabetic rats was not reversed by islet transplantation. Likewise, tissue AGE accumulation and particularly upregulation of glomerular ECM and transforming growth factor (TGF)-beta gene expression, which are believed to play a role in the pathogenesis of altered renal function and structure in diabetes, were normalized in transplanted rats from study A and study B, but not in those from study C. These experiments show that restoration of euglycemia by islet transplants is capable of preventing experimental diabetic glomerulopathy and reversing early change

Topics: Animals; Cohort Studies; Collagen; Creatinine; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Disease Models, Animal; Extracellular Matrix Proteins; Fibronectins; Gene Expression; Islets of Langerhans Transplantation; Kidney Glomerulus; Male; Prospective Studies; Proteinuria; Random Allocation; Rats; Rats, Inbred Lew; RNA, Messenger; Time Factors; Transforming Growth Factor beta

To elucidate the effect of imidapril, an angiotensin-converting enzyme inhibitor, on molecular events in progressive glomerulosclerosis, we administered imidapril to 5/6 nephrectomized rats and measured the glomerular expression of genes for transforming growth factor (TGF)-beta1, fibronectin and collagen IV. Glomerular TGF-beta1, fibronectin and collagen IV mRNAs in nephrectomized rats were significantly higher than those in sham-operated rats. Treatment with imidapril for 10 weeks significantly reduced the enhanced glomerular expression of TGF-beta1 and collagen IV mRNA in nephrectomized rats, and prevented the associated proteinuria and glomerulosclerosis. Thus, imidapril may arrest progressive glomerulosclerosis by inhibiting the expression of TGF-beta1 and collagen IV.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Pressure; Collagen; Fibronectins; Gene Expression; Imidazoles; Imidazolidines; Kidney Glomerulus; Male; Nephrectomy; Proteinuria; Rats; Rats, Sprague-Dawley; RNA, Messenger; Sclerosis; Transforming Growth Factor beta

The renal protective properties of candesartan cilexetil (TCV-116), an angiotensin II type 1 receptor antagonist (AT1A), and enalapril, an angiotensin I converting enzyme inhibitor (ACEI), were investigated in 5/6 nephrectomized (NX) rats. Candesartan cilexetil (1 mg/kg/day) and enalapril (10 mg/kg/day) were administered orally to 5/6 NX rats for four weeks (during the early phase of disease development) or 16 weeks (through the late phase). In vehicle-treated rats, proteinuria, glomerulosclerosis, interstitial mononuclear cell (MNC) infiltration and interstitial fibrosis developed. Moreover, immunohistological studies showed enhanced expression of transforming growth factor-beta 1 (TGF-beta 1) in the injured glomeruli. Both drugs inhibited these adverse changes in the early phase. In the late phase, the progressive proteinuria, interstitial MNC infiltration were attenuated by both drugs. However, candesartan cilexetil significantly inhibited the progression of glomerulosclerosis, the expression of TGF-beta 1 and the interstitial fibrosis, while enalapril did not. Candesartan cilexetil and enalapril showed comparable hypotensive effects after the 16-week administration. These results indicate that candesartan cilexetil shows a more potent protective effect than enalapril against the progression of renal injury in the late phase. Thus, an AT1A might be more useful than an ACEI for the treatment of patients with chronic renal failure.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Disease Progression; Enalapril; Fibrosis; Glomerular Filtration Rate; Glomerulosclerosis, Focal Segmental; Kidney Failure, Chronic; Male; Nephrectomy; Proteinuria; Rats; Rats, Sprague-Dawley; Tetrazoles; Transforming Growth Factor beta

We previously reported a new animal model of progressive glomerulonephritis induced by a single intravenous injection of the anti-Thy-1 monoclonal antibody MoAb 1-22-3 into uninephrectomized rats (Clin Exp Immunol 102: 181-185, 1995). We examined the effects of angiotensin II (Ang II) receptor antagonist (candesartan) on the clinical features and morphological lesions of this new model. By 10 weeks after induction of nephritis, untreated rats had developed hypertension, massive proteinuria, renal dysfunction, and severe glomerular injury, while uninephrectomized control rats had not. There was a significant increase in levels of glomerular protein and cortical mRNA for transforming growth factor-beta (TGF-beta) and type I and type III collagens in untreated nephritic rats. Ten week treatments with candesartan and hydralazine significantly reduced blood pressure (BP) to an equal extent. Candesartan, but not hydralazine, prevented proteinuria, normalized renal function, and ameliorated glomerular injury. Candesartan also reduced levels of glomerular protein and cortical mRNA for TGF-beta and type I and type III collagens, while hydralazine did not. These findings suggest that candesartan prevents progression to end-stage renal failure by modulating the effects of Ang II at least in part on the production of TGF-beta and type I and type III collagens, and not merely on systemic BP.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Collagen; Glomerular Mesangium; Glomerulonephritis, Membranoproliferative; Hypertension, Renal; Proteinuria; Rats; RNA, Messenger; Tetrazoles; Transforming Growth Factor beta

Ischemic injury to cadaver organs is a major risk factor for development of chronic organ dysfunction. We have recently shown that the B7 costimulatory pathway plays a critical role in early organ dysfunction developing after renal cold ischemia/reperfusion injury. We extended these observations to investigate the role of this pathway in the development and progression of chronic organ dysfunction following such injury. Uninephrectomized rats which underwent cold ischemia/reperfusion injury developed progressive proteinuria as compared to uninephrectomized controls. Animals treated with CTLA4Ig, which blocks B7 costimulation, starting on the day of injury had significantly better long-term survival and developed significantly less proteinuria than control animals treated with control Ig. RT-PCR analysis of kidney tissue showed significant reduction in expression of activation and inflammatory cytokines, chemoattractants, and growth factors, as compared to controls. Delaying administration of CTLA4Ig for one week, but not four weeks, after injury was still effective in ameliorating development of progressive proteinuria. Interestingly, selective blockade of B7-1 by a mutant form of CTLA4Ig had no effect on early or chronic organ dysfunction. These findings indicate the long-term functional and molecular consequences of experimental cold ischemia/reperfusion injury, and suggest that B7-2 is critical in the development of organ dysfunction following ischemic injury, even in the absence of alloantigen.

Topics: Abatacept; Animals; Antigens, CD; Antigens, Differentiation; B7-1 Antigen; CD28 Antigens; Chemokine CCL2; Chemokine CCL5; Cold Temperature; Cryopreservation; CTLA-4 Antigen; Disease Progression; Endothelins; Gene Expression; Immunoconjugates; Immunosuppressive Agents; Intercellular Adhesion Molecule-1; Interferon-gamma; Interleukins; Kidney; Male; Nephrectomy; Proteinuria; Rats; Rats, Inbred Lew; Receptors, Interleukin-2; Reperfusion Injury; RNA, Messenger; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Increasing clinical evidence suggests that delayed initial function secondary to ischemia/reperfusion injury alone, and particularly in combination with early episodes of acute rejection, reduces kidney allograft survival over time.. We investigated changes developing over the long term following a standardized ischemia/reperfusion insult in a Lewis rat model. The left kidney was isolated in a uninephrectomized host and cooled, and the pedicle was clamped for 45 min. Animals were followed for 48 weeks after initial renal injury. Organs were removed serially (4, 8, 16, 24, 32, 40, and 48 weeks) for immunohistology and reverse transcriptase polymerase chain reaction.. Progressive proteinuria developed after 8 weeks. By immunohistology, CD4+ leukocytes and ED-1+ macrophages infiltrated the ischemic organs in parallel with up-regulation of major histocompatibility complex class II antigen expression. Because macrophages have been shown to be critical in chronic changes in other models, they were examined primarily in these studies. By reverse transcriptase polymerase chain reaction, macrophage-derived, fibrosis-inducing factors (transforming growth factor-beta, interleukin 6, and tumor necrosis factor-alpha) remained highly and constantly expressed throughout the follow-up period. The long-term influence of initial treatment with the soluble form of P-selectin glycoprotein ligand-1, a soluble ligand for P- and E-selectin, was then examined. All functional and structural changes remained at relative baseline, similar to uninephrectomized controls.. These data suggest that blocking the initial selectin-mediated step after ischemia/reperfusion injury, which triggers significant early cellular and molecular events, also reduces later renal dysfunction and tissue damage over time. In part, the findings may be explained by the sparing of functioning nephron units, which if destroyed or compromised by the original insult, may contribute to long-term graft failure. This approach may be important clinically in the transplantation of kidneys from non-heart-beating or marginal donors or organs experiencing prolonged ischemic times.

Topics: Animals; Chemokine CCL2; Endothelin-1; Interleukin-6; Ischemia; Kidney; Ligands; Male; Membrane Glycoproteins; Mucins; P-Selectin; Polymerase Chain Reaction; Proteinuria; Rats; Rats, Inbred Lew; Reperfusion Injury; RNA, Messenger; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Transcription factors nuclear factor-kappa B (NF-kappa B) and activator protein-1 (AP-1) play an important role in the induction of pro-inflammatory factors such as cytokines and cell adhesion molecules, which could be involved in the pathogenesis of glomerulonephritis. We have recently reported the pathogenic significance of NF-kappa B activation in experimental glomerulonephritis in rats. In this study, we investigated the pathogenic relevance of AP-1 activation in nephrotoxic serum (NTS)-induced glomerulonephritis. Increased AP-1 DNA-binding activity was detected in nephritic glomeruli by a gel shift assay. The kinetics of AP-1 activation was similar to that of NF-kappa B. Activation of both NF-kappa B and AP-1 preceded proteinuria, an important pathophysiological parameter for glomerulonephritis. Treatment with prednisolone, a glucocorticoid hormone, prevented activation of both NF-kappa B and AP-1 in glomeruli and subsequent mRNA expression of NF-kappa B- and AP-1-regulated genes. Prednisolone was also effective therapeutically and reduced DNA-binding activities of NF-kappa B and AP-1 which are already activated in nephritic glomeruli. These results suggest that activated NF-kappa B and AP-1 may play an important pathogenic role in glomerulonephritis and the anti-nephritic action of glucocorticoids may be mediated through the suppression of these transcription factors.

Topics: Animals; Binding, Competitive; Cell Nucleus; Chemokine CCL2; DNA; DNA-Binding Proteins; Gene Expression; Glomerulonephritis; Glucocorticoids; Inflammation; Intercellular Adhesion Molecule-1; Interleukin-1; Kidney Glomerulus; Male; NF-kappa B; Prednisolone; Proteinuria; Rats; Rats, Inbred WKY; Time Factors; Transcription Factor AP-1; Transforming Growth Factor beta

To assess the chronic in vivo effects of OPC-21268, a vasopressin-V1 receptor antagonist, on renal injury, we investigated the mRNA expressions of platelet-derived growth factor (PDGF) B-chain, transforming growth factor (TGF)-beta1 and proliferating cell nuclear antigen (PCNA) in the glomeruli of spontaneously hypertensive rats (SHR) treated with OPC-21268 for 3 weeks. SHR aged 10 weeks were given 2% NaCl in drinking water for 3 weeks. The OPC group was fed a 0.5% OPC-21268-containing diet for 3 weeks and the control group was given a normal diet. There were no significant changes in the time course of systolic blood pressure, heart rate, urine volume, or urinary sodium, protein and N-acetyl-beta-glucosaminidase (NAG) excretion between the two groups. Serum electrolytes, protein and creatinine levels also did not differ between the groups. The mRNA expressions of PDGF B-chain, TGF-beta1 and PCNA in the glomerulus were examined using reverse transcriptase-polymerase chain reaction (RT-PCR) methods. The mRNA expressions of PDGF B-chain and PCNA among these were significantly suppressed in the OPC group. No significant differences in renal histology including the organ weights were found between the two groups; however, the glomerular size tended to be enlarged in the OPC group. These findings suggest that chronic V1-receptor blockade directly inhibits the glomerular proliferative injury of salt-loaded SHR at the established hypertension stage.

Topics: Acetylglucosaminidase; Animals; Antidiuretic Hormone Receptor Antagonists; Blood Pressure; Body Weight; Growth Substances; Heart Rate; Hypertension; Kidney Glomerulus; Organ Size; Piperidines; Platelet-Derived Growth Factor; Polymerase Chain Reaction; Proliferating Cell Nuclear Antigen; Proteinuria; Quinolones; Random Allocation; Rats; Rats, Inbred SHR; RNA, Messenger; Sodium; Transforming Growth Factor beta; Urine

Several lines of evidence suggest that local production of transforming growth factor-beta (TGF-beta) contributes to renal disease, particularly to the accumulation of the extracellular matrix protein that characterizes glomerulosclerosis and interstitial fibrosis. We have examined whether elevated levels of circulating TGF-beta adversely affect the kidney. We have studied mice that are transgenic for an active form of TGF-beta 1 under the control of murine albumin promoter and enhancer DNA sequences. These mice express the transgene exclusively in the liver and have elevated plasma concentrations of TGF-beta 1. Renal disease was seen in two of three lines of Alb/TGF-beta 1 transgenic mice; these two lines had the highest levels of hepatic transgene expression and the highest plasma TGF-beta 1 levels. Histologic abnormalities, which included mesangial expansion and thickened capillary loops, were noted in the glomeruli by 3 weeks of age. Interstitial fibrosis and tubular atrophy appeared subsequently. Mice from Line 25, the line with highest levels of TGF-beta 1, developed proteinuria by 5 weeks of age. These mice subsequently manifested nephrotic syndrome with ascites and progressive azotemia; uremic death occurred in more than 25% of the mice by 15 weeks of age. The glomeruli contained immune deposits in subendothelial and mesangial locations, but complement deposition was infrequent. Ultrastructural examination revealed an increase in extracellular matrix material, including collagen fibrils, in subendothelial and mesangial locations. Increased levels of circulating TGF-beta 1 induced progressive renal disease that was characterized by mesangial expansion, accumulation of glomerular immune deposits and matrix proteins, and interstitial fibrosis in this transgenic mouse model. These data suggest that chronically elevated circulating levels of TGF-beta 1 induce progressive glomerulosclerosis.

Topics: Animals; Glomerulonephritis; Kidney; Kidney Diseases; Kidney Function Tests; Kidney Glomerulus; Longitudinal Studies; Mice; Mice, Transgenic; Proteinuria; Transforming Growth Factor beta

IgA nephropathy is one of the most common forms of glomerular disease. Nearly 25% of affected patients progress to end-stage renal disease over a 20-25-y follow-up period. IgA-containing immune complexes stimulate oxygen-free radical production by mesangial cells in vitro. The excessive oxidant stress may mediate glomerular injury in this disorder. Therefore, we studied whether dietary supplementation with the antioxidant agent, vitamin E, attenuates renal disease in an experimental model of incipient IgA nephropathy with mild kidney inflammation. IgA nephropathy was induced in male Lewis rats by oral immunization with 0.1% bovine gamma-globulin (BGG)-containing drinking water for 8 wk. At the completion of this period, animals received BGG, 1 mg/dose i.v., on three successive days. Experimental rats (n = 10) received a specially formulated diet containing 100 IU of vitamin E/kg of chow, whereas control animals (n = 10) were fed chow containing 30 IU of vitamin/kg of chow. The BGG immunization regimen induced mesangial IgA deposition in all rats. Vitamin E supplementation resulted in a nearly 5-fold increase in the serum vitamin E concentration. Vitamin E-treated rats gained more weight and had a lower incidence of hematuria, 20% versus 80% (p < 0.03). Moreover, proteinuria was decreased by 50%, and reduced renal plasma flow was restored to normal, compared with untreated rats with IgA nephropathy. Glomerular hypertrophy occurred in animals with IgA nephropathy, but less so in those receiving vitamin E supplementation. Renal cortical malondialdehyde content was reduced from 1.55 +/- 0.10 to 1.22 +/- 0.09 nmol/mg of protein (p < 0.01) in rats fed the vitamin E-enriched diet. Finally, renal transforming growth factor-beta 1 gene expression was reduced by 34% in rats with IgA nephropathy receiving vitamin E treatment (p < 0.05). We conclude that experimental IgA nephropathy is associated with increased renal oxidant injury. Dietary treatment with the antioxidant agent, vitamin E, attenuated renal functional and structural changes in this experimental glomerulopathy. These studies support the importance of clinical trials for the evaluation of the efficacy of antioxidant therapy in patients with IgA nephropathy.

Topics: Animals; Antioxidants; Blood Glucose; Blood Pressure; Blood Urea Nitrogen; Cattle; Food, Fortified; gamma-Globulins; Glomerulonephritis, IGA; Hematocrit; Humans; Kidney; Kidney Cortex; Liver; Male; Proteinuria; Rats; Rats, Inbred Lew; Sodium; Transforming Growth Factor beta; Vitamin E

Topics: Biopsy; Blood Pressure; Chronic Disease; Drug Therapy, Combination; Epidermal Growth Factor; Fibroblast Growth Factor 2; Graft Rejection; Growth Substances; Humans; Immunosuppressive Agents; Interleukin-1; Kidney Transplantation; Platelet-Derived Growth Factor; Polymerase Chain Reaction; Proteinuria; RNA, Messenger; Transcription, Genetic; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Induction of acute nephritis in the rat by injecting anti-glomerular basement membrane (GBM) antiserum is accompanied by a transient increase in angiotensin II generation in blood circulation within the first 24 h and a subsequent elevation of transforming growth factor-beta 1 (TGF-beta 1) mRNA levels in kidney cortex with a peak at days 7-8. Studies were carried out to determine whether the increased generation of angiotensin II plays a role in the elevation of TGF-beta 1 mRNA. Elevation of TGF-beta 1 mRNA levels 7 d after injection of antiserum was significantly inhibited by a successive daily administration of TCV-116, angiotensin II type 1 receptor antagonist, at 1 mg/kg/d from days 0 to 2 or from days 0 to 6, while it was not influenced by a single administration of this dose on day 0. In addition, angiotensin II infusion or 24 h at a rate of 50 ng/min did not alter the level of TGF-beta1 mRNA which was measured 6 d after the infusion. These results suggest that the anti-GBM antiserum-induced increase in TGF-beta 1 expression in the kidney is not responsible for angiotensin II generated in the blood circulation during the early phase of acute nephritis, but iis probably mediated by angiotensin II generated locally in the kidney.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Animals; Basement Membrane; Benzimidazoles; Biphenyl Compounds; Glomerulonephritis; Kidney; Kidney Cortex; Kidney Glomerulus; Male; Proteinuria; Rats; Rats, Sprague-Dawley; RNA, Messenger; Tetrazoles; Transforming Growth Factor beta

A new animal model of progressive glomerulosclerosis was developed by administering a single i.v., injection of MoAb 1-22-3 to unilaterally nephrectomized rats. Renal morphological analysis revealed that glomerular lesions characterized by mesangial cell proliferation and mesangial matrix expansion were induced in about 95% of the glomeruli. Approximately 20% of the glomeruli of the unilaterally nephrectomized rats showed sclerosis or segmental sclerosis by week 6 after MoAb injection and crescent formation was observed in some glomeruli (ca 4%). Cellular infiltration was also noted in some parts of the interstitium. Increased expression of transforming growth factor-beta (TGF-beta) was observed in the unilaterally nephrectomized rats treated with MoAb 1-22-3, but we could not demonstrate pathological involvement of platelet-derived growth factor (PDGF), even though early-stage mesangial cell proliferation was observed. The mechanism of mesangial cell proliferation in this model remains to be elucidated. The relatively short period of time needed to induce the sclerotic changes in considered to be a great advantage of this model for clarifying the mechanisms involved in the chronic progression of mesangial proliferative glomerulonephritis.

Topics: Animals; Antibodies, Monoclonal; Chronic Disease; Female; Glomerulonephritis; Kidney; Nephrectomy; Platelet-Derived Growth Factor; Proteinuria; Rats; Rats, Wistar; Transforming Growth Factor beta

The present study was carried out to test whether transforming growth factor beta (TGF beta) plays a pathological role in the induction or progression of glomerulonephritis in a murine model of systemic lupus erythematosus (SLE), and whether dietary supplementation with fish oil (FO) can modulate the expression of TGF beta. Weanling female (NZB x NZW) F1 (B/W) mice were divided into three groups. One group was fed an unmanipulated diet (lab. chow; LC) and the other two groups were fed a nutritionally adequate semipurified diet supplemented with 10% CO or FO. Both water and food were provided ad libitum. Proteinuria and serum anti-dsDNA antibody levels were measured to assess disease progression. Mice were killed at 3.5 and 6.5 months of age and renal mRNA levels for TGF beta isoforms, fibronectin-1 (FN-1) and intercellular adhesion molecule-1 (ICAM-1) were studied by Northern blot analysis. TGF beta 1 protein levels were also examined in kidneys by Western blot analysis. Our results indicate that at 3.5 months of age, when urinary protein levels were undetectable and very low levels of anti-dsDNA were detected, no mRNA signal could be detected for TGF beta isoforms, ICAM-1 and FN-1 in either dietary group. However, at 6.5 months, the FO-fed mice, compared to LC and CO, had [1] greatly reduced proteinuria (LC: 2-3+, CO: 2-3+; FO: trace -1+) and serum anti-dsDNA antibodies; [2] improved survival (CO: 100% death (15/15) occurred by 8 months; FO: 50% were alive at 12 months (8/15) and [3] reduced renal TGF beta 1 mRNA and protein levels. TGF beta 2 and beta 3 were not significantly affected by FO diet. Similarly, lower levels of renal FN-1 and ICAM-1 mRNA were observed in FO fed mice. These data indicate that in B/W mice on a FO diet, prolonged survival and amelioration of renal disease may be attributed at least in part to lower levels of TGF beta 1 mRNA and protein in the kidneys.

Topics: Adjuvants, Immunologic; Animals; Autoimmune Diseases; Blotting, Northern; Blotting, Western; Body Weight; Fatty Acids, Omega-3; Female; Kidney; Lupus Nephritis; Mice; Mice, Inbred NZB; Proteinuria; RNA, Messenger; Transforming Growth Factor beta

We have previously reported that the mRNA levels of extracellular matrix (ECM) components including alpha 1(I), alpha 1(III), and alpha 1(IV) collagen chains, laminin B1 and B2 chains, and growth factors including tumor necrosis factor (TNF)-alpha, platelet-derived growth factor (PDGF)-B chain, transforming growth factor (TGF)-beta, and basic fibroblast growth factor (FGF) all increase with age in diabetic glomeruli. The present study was designed to assess whether glomerular expression of these mRNAs in rat diabetic glomeruli is affected by a specific endothelin receptor A antagonist, FR139317. Diabetes was produced by streptozotocin injection, and animals were divided into four groups: untreated diabetic rats, FR139317-treated diabetic rats, control nondiabetic rats, and FR139317-treated control rats. FR139317 treatment was continued for 24 weeks. FR139317 attenuated the rise in creatinine clearance (P < 0.01) and reduced urinary protein excretion (P < 0.01) in diabetic rats, but did not affect blood pressure. FR139317 attenuated the increases in glomerular mRNA levels of alpha 1(I) (P < 0.01), alpha 1(III) (P < 0.01), and alpha 1(IV) (P < 0.01) collagen chains, laminin B1 (P < 0.01) and B2 (P < 0.01) chains, TNF-alpha (P < 0.01), PDGF-B (P < 0.01), TGF-beta (P < 0.001) and basic FGF (P < 0.01) in diabetic rats. However, FR139317 did not affect these mRNA levels in glomeruli of control rats. These findings suggest that FR139317 may be useful in the treatment of diabetic glomerulopathy by reducing mRNA levels of ECM components and growth factors.

Topics: Aging; Animals; Azepines; Blood Pressure; Collagen; Creatinine; Diabetes Mellitus, Experimental; Endothelin Receptor Antagonists; Extracellular Matrix Proteins; Fibroblast Growth Factor 2; Gene Expression; Growth Substances; Indoles; Kidney Glomerulus; Laminin; Male; Platelet-Derived Growth Factor; Proteinuria; Rats; Rats, Sprague-Dawley; Reference Values; RNA, Messenger; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Rats with significant proteinuria induced by daily injections of bovine serum albumin develop interstitial inflammation and fibrosis. The present study was designed to investigate the molecular basis of interstitial monocyte (Mø) recruitment and early interstitial fibrosis. Groups of rats were sacrificed after one, two and three weeks. Despite an increase in interstitial Mø at week 1, whole kidney mRNA levels were not elevated for monocyte chemoattractant protein-1 (MCP-1), osteopontin or vascular cell adhesion molecule-1 (VCAM-1). Only osteopontin mRNA levels were significantly elevated in the renal cortex at four days. At two and three weeks, MCP-1 and osteopontin mRNA levels were increased and the proteins showed distinct tubular patterns of distribution. By immunostaining increased expression of VCAM-1 and intercellular adhesion molecule-1 (ICAM-1) was restricted to their presence or the surface of the interstitial inflammatory cells. TGF-beta 1 mRNA levels were increased at weeks 1, 2 and 3 (2.1, 2.9, 3.6x); interstitial and occasional cortical tubular cells expressed TGF-beta 1 mRNA and protein. There was a progressive rise in the number of cortical interstitial fields with increased staining for collagen (col) 1 (18, 29, 44%), col III (39, 61, 63%), col IV (7, 13, 29%), laminin (4, 10, 30%), fibronectin (14, 28, 37%), tenascin (19, 22, 14%) and in total renal col measured biochemically (1.1, 1.4, 2.0x) at weeks 1, 2 and 3, respectively. Renal matrix protein mRNA levels were variable and not always predictive of fibrosis. Only col I and tenascin levels were increased at week 1; all matrix protein mRNA levels except col IV were increased at week 2; but only tenascin, laminin and col IV mRNA levels remained elevated at three weeks. Plasminogen activator inhibitor-1 (PAI-1) and tissue inhibitor of metallo-proteinases (TIMP)-1 mRNA levels were significantly increased at two weeks. During the three weeks there was no change in urokinase, stromelysin or TIMP-3 mRNA levels. These results suggest that both increased matrix protein synthesis and altered matrix remodeling/degradation contribute to the final interstitial fibrogenic process in rats with protein-overload proteinuria. Mø, one of the sources of TGF-beta 1, infiltrate the interstitium by complex recruitment mechanisms which may depend in part on osteopontin, ICAM-1 and VCAM-1 expression.

Topics: Animals; Cell Movement; Extracellular Matrix Proteins; Female; Fibrosis; Gene Expression; Glycoproteins; Kidney; Kidney Diseases; Monocytes; Nephritis; Protease Inhibitors; Proteins; Proteinuria; Rats; Rats, Inbred Lew; Reference Values; RNA, Messenger; Tissue Inhibitor of Metalloproteinases; Transforming Growth Factor beta

We have previously shown beneficial effects of dietary protein restriction on transforming growth factor beta (TGF-beta) expression and glomerular matrix accumulation in experimental glomerulonephritis. We hypothesized that these effects result from restriction of dietary L-arginine intake. Arginine is a precursor for three pathways, the products of which are involved in tissue injury and repair: nitric oxide, an effector molecule in inflammatory and immunological tissue injury; polyamines, which are required for DNA synthesis and cell growth; and proline, which is required for collagen production. Rats were fed six isocaloric diets differing in L-arginine and/or total protein content, starting immediately after induction of glomerulonephritis by injection of an antibody reactive to glomerular mesangial cells. Mesangial cell lysis and monocyte/macrophage infiltration did not differ with diet. However, restriction of dietary L-arginine intake, even when total protein intake was normal, resulted in decreased proteinuria, decreased expression of TGF-beta 1 mRNA and TGF-beta 1 protein, and decreased production and deposition of matrix components. L-Arginine, but not D-arginine, supplementation to low protein diets reversed these effects. These results implicate arginine as a key component in the beneficial effects of low protein diet.

Topics: Animals; Arginine; Blood Pressure; Body Weight; Diet, Protein-Restricted; Dietary Proteins; Gene Expression; Glomerular Mesangium; Glomerulonephritis; Immune Sera; Kidney Glomerulus; Nitrites; Proteinuria; Proteoglycans; Rats; RNA, Messenger; Thy-1 Antigens; Time Factors; Transforming Growth Factor beta

We studied the effect of the angiotensin converting enzyme (ACE) inhibitor, quinapril, on the clinical and morphological lesions of a normotensive model of immune complex nephritis. Untreated rats developed massive nephrotic syndrome, intense cell proliferation and glomerular and tubulointerstitial lesions. In the renal cortex of nephritic rats there was a significant increase in gene expression of TGF-beta 1, fibronectin and collagens, and ACE activity. Systolic blood pressure remained normal with progression of the disease. Administration of quinapril for three weeks to animals with glomerular lesions (proteinuria 20 to 50 mg/day) avoided the development of intense proteinuria (79 +/- 28 vs. 589 +/- 73 mg/day, P < 0.001) and decreased cell proliferation, glomerulosclerosis, tubulointerstitial lesions, and inflammatory infiltrates. Cortical gene expression of TGF-beta 1 and matrix proteins was also diminished. ACE activity was inhibited by 68% in renal cortex. These results show that quinapril administration to normotensive rats with immune complex nephritis decreases proteinuria and glomerular and tubulointerstitial lesions, probably modulating the local angiotensin II generation and its effects on cell growth, TGF beta and matrix protein synthesis.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Autoimmune Diseases; Cell Division; Extracellular Matrix; Female; Fluorescent Antibody Technique, Direct; Gene Expression; Isoquinolines; Nephritis, Interstitial; Peptidyl-Dipeptidase A; Proteinuria; Quinapril; Rats; Rats, Wistar; RNA, Messenger; Tetrahydroisoquinolines; Transforming Growth Factor beta

The urinary transforming growth factor beta (TGF-beta) excretion was measured in 33 patients including 10 with systemic lupus erythematosus (SLE), 8 with focal glomerular sclerosis (FGS), 9 with IgA nephropathy (IgAN), and 6 with membranous nephropathy (MN), and in 7 healthy subjects by enzyme-linked immunosorbent assay using a monoclonal antibody specific for TGF-beta 1 + 2 + 3. A significantly increased urinary TGF-beta excretion was observed in FGS patients (555.5 +/- 458.4 ng/mg Cr) as compared with normal controls (46.9 +/- 43.9 ng/mg Cr) (p < 0.05) and a relative increase in SLE patients (96.4 +/- 58.2 ng/mg Cr) and a decrease in MN patients (24.8 +/- 13.3 ng/mg Cr). In contrast, there was no difference in TGF-beta excretion between IgAN patients (54.1 +/- 37.4 ng/mg Cr) and normal controls. A correlation between the amount of proteinuria and TGF-beta was not found. As has been previously demonstrated in experimental studies, TGF-beta may play a similar role in human glomerular diseases. The results obtained in this study raised the possibility that extracellular matrix might be produced by glomerular cells in vivo under the control of TGF-beta and that TGF-beta might act as a stimulator for the development of glomerulosclerosis.

Topics: Adolescent; Adult; Aged; Enzyme-Linked Immunosorbent Assay; Female; Glomerulonephritis, IGA; Glomerulonephritis, Membranous; Glomerulosclerosis, Focal Segmental; Humans; Lupus Erythematosus, Systemic; Male; Middle Aged; Proteinuria; Reference Standards; Transforming Growth Factor beta

Nephrotic syndrome induced by puromycin aminonucleoside (PAN) is characterized by tubulointerstitial (TI) inflammation, foci of TI fibrosis, and increased renal mRNA levels for matrix genes, the tissue inhibitor of metalloproteinases (TIMP), and the transforming growth factor-beta 1 (TGF-beta 1). To investigate the ability of a low-protein diet known to decrease TI inflammation to alter the degree of renal fibrosis, we studied four groups of rats: 27% protein PAN, 27% protein control, 8% protein PAN, and 8% protein control. Renal TGF-beta 1 mRNA levels correlated with the number of interstitial macrophages (r = 0.76) and were significantly reduced by dietary protein restriction. On day 10, Northern blot analysis showed that the elevated renal mRNA levels for procollagens alpha 1 (I), alpha 1(III), and alpha 2(IV) and fibronectin in the PAN-treated rats were significantly reduced by 8% dietary protein. In contrast, genes regulating matrix degradation (stromelysin and TIMP) were relatively unchanged by the low-protein diet. The number of foci of interstitial fibrosis and total renal collagen were greater in the PAN + 27% protein group than in the control groups. Both parameters of fibrosis were partially normalized in the PAN + 8% protein group. The results of this study suggest that dietary protein restriction attenuates TI fibrosis in PAN-induced nephrosis by partially reversing the increase in renal matrix synthesis. This effect was associated with decreased renal expression of the fibrogenic cytokine TGF-beta 1, which may be partially mediated by the concomitant reduction in the number of interstitial inflammatory macrophages.

Topics: Animals; Cholesterol; Dietary Proteins; Extracellular Matrix Proteins; Female; Fibrosis; Kidney; Nephritis; Nephrotic Syndrome; Proteinuria; Rats; Rats, Inbred Lew; RNA, Messenger; Transforming Growth Factor beta

This study was designed to investigate the mechanisms by which marine lipids rich in long chain omega-3 fatty acids inhibit autoimmune disease and prolong the survival rate in female (NZB/NZW) F1 (B/W) mice, an animal model for human SLE. Nutritionally adequate semipurified diets containing at 10% either corn oil (CO) or fish oil (FO) were fed from 1 mo of age and were monitored for proteinuria and survival. Proteinuria was detected earlier and became progressively severe in CO-fed mice. The average life span was significantly shortened by the CO diet (266.7 days +/- 12.5), whereas FO extended the survival significantly (402.1 days +/- 26.1; p < 0.001). A cross-sectional study at 6.5 mo of age revealed an increased proliferative response to T cell mitogens including bacterial superantigens and decreased serum anti-dsDNA Ab titers in the FO group compared with the CO group. Furthermore, splenocytes from the FO group when stimulated with Con A had higher IL-2 and lower IL-4 production similar to that of young (3.5 mo) mice. Flow cytometric analyses of splenocytes revealed lower Ig+, higher lymphocyte endothelial cell adhesion molecule-1, and lower Pgp-1+ cells within CD4+ and CD8+ subsets in FO-fed mice. Also, elevated IL-2 and IL-4 and significantly higher TGF-beta 1 and lower c-myc and c-ras mRNA expression and higher TGF-beta 1 and significantly lower c-Myc and c-Ha-Ras proteins were detected in spleens of FO-fed mice. Fatty acid analysis revealed significantly higher linoleic (18:2 omega-6) and arachidonic (20:4 omega-6) acid levels in splenocytes of the CO-fed group and higher eicosapentaenoic (20:5 omega-3) and docosahexanoic (22:6 omega-3) acid levels in the FO-fed group, indicating that changes in membrane fatty acid composition may contribute to the altered immune function and gene expression during the development of murine SLE.

Topics: Animals; Antibodies, Antinuclear; Autoimmune Diseases; Body Weight; Disease Models, Animal; Fatty Acids, Omega-3; Female; Gene Expression; In Vitro Techniques; Interleukin-2; Interleukin-4; Lupus Erythematosus, Systemic; Lymphocyte Activation; Lymphocyte Subsets; Mice; Mice, Inbred NZB; Oncogenes; Proteinuria; RNA, Messenger; Spleen; Transforming Growth Factor beta

In humans, alcoholic liver disease is frequently associated with IgA mesangial deposits, microscopic hematuria and a small amount of proteinuria, identifying a secondary form of IgA nephropathy. Alcoholic liver disease is almost always associated with nutritional deficiencies.. In order to examine the relationship between alcohol intake and/or inadequate diet and IgA nephropathy, groups of 4 week-old-male Lewis rats were maintained on a lipotrope-deficient (LD) diet (N = 20), intragastric infusions of a commercial whiskey (1.5 ml/100 gm body weight) three times a week, and regular chow (N = 23) or both intragastric whiskey infusion and an LD diet (N = 17). A fourth control group (N = 19) was given no whiskey and normal chow.. All rats given the LD diet had marked steatosis and elevated "liver" enzymes. Changes were more severe, and with early bridging fibrosis and nodule formation in those also given whiskey, associated with increased hepatic content of mRNA encoding transforming growth factor-beta. A moderate steatosis without alteration in serum enzymes or transforming growth factor-beta expression was found in rats given whiskey (all p < 0.0001) compared with controls. IgA accumulated in hepatic sinusoids instead of in canaliculi and bile ducts, suggesting impaired transport of IgA and IgA immune complexes from blood to bile, in rats given an LD diet and/or whiskey infusion. A moderate increase in mesangial matrix was observed only in rats given both whiskey and an LD diet. Bright granular IgA and mild granular C3 mesangial deposits and electron-dense deposits were evident in 63 to 70% of experimental rats (all p < 0.001) versus only trace deposits in 5 to 11% of controls. Moderate IgG codeposits were present in 34 to 55% of rats given the LD diet and/or whiskey (all p < 0.02), versus trace deposits in 10% of controls. Significant hematuria and proteinuria were observed in rats given the LD diet and/or whiskey (p < 0.0001) versus controls. Intestinal permeability measured by xylose absorption was significantly increased relative to controls only in rats given both whiskey and the LD diet (p < 0.001). Serum IgA specific for selected alimentary antigens was increased relative to controls in 75 to 100% of the experimental rats.. The combination of LD diet and alcohol intake, which mimics the human alcoholic condition, promotes hepatic and renal changes, leading to hepatocellular injury and a secondary form of IgA nephropathy.

Topics: Alcoholism; Animal Nutritional Physiological Phenomena; Animals; Deficiency Diseases; Disease Models, Animal; Fluorescent Antibody Technique; Glomerulonephritis, IGA; Immunoglobulin A; Intestinal Absorption; Kidney; Liver; Liver Diseases, Alcoholic; Male; Microscopy, Electron; Proteinuria; Rats; Rats, Inbred Lew; RNA, Messenger; Transforming Growth Factor beta; Xylose

Focal glomerular sclerosis was induced in rats by chronic injections of puromycin aminonucleoside (PAN) on Days 0, 27, 34, and 41 and by unilateral nephrectomy on Day 22. Rats were sacrificed on Days 0, 8, and 20 (acute phase) and on Days 48, 60, and 80 (sclerotic phase). The percentage of sclerosing glomeruli was 16.6% on Day 48 and increased significantly to 72.8% on Day 80. We examined glomerular mRNA levels for proliferating cell nuclear antigen (PCNA), platelet-derived growth factor (PDGF)-A and B chains, transforming growth factor (TGF)-beta, epidermal growth factor (EGF), insulin-like growth factor (IGF)-I, and basic fibroblast growth factor (bFGF) on Days 0, 8, 20, 48, 60, and 80. Although these growth factor mRNA levels showed little change in glomeruli until Day 20, all growth factor mRNA levels increased in glomeruli during the sclerotic phase of PAN nephrosis as glomerular sclerosis progressed. On Day 80, mRNA levels for PCNA, PDGF-A and B chains, TGF-beta, EGF, IGF-I, and bFGF increased 12-, 10-, 12-, 15-, 2-, 2-, and 8-fold, respectively, in the glomeruli of PAN-treated rats with marked glomerular sclerosis when compared with control rats. Unilateral nephrectomy without PAN administration did not cause glomerular sclerosis up to Day 80 and mRNA levels for PCNA, PDGF-A and -B chains, TGF-beta, EGF, IGF-I, and bFGF in this group were almost the same as those in the normal sham-operated group. These data suggest that changes in growth factor mRNA levels in glomeruli may contribute to the development of PAN-induced glomerular sclerosis.

Topics: Animals; Blotting, Northern; Epidermal Growth Factor; Fibroblast Growth Factor 2; Gene Expression; Glomerulosclerosis, Focal Segmental; Growth Substances; Insulin-Like Growth Factor I; Kidney Glomerulus; Male; Nuclear Proteins; Platelet-Derived Growth Factor; Proliferating Cell Nuclear Antigen; Proteinuria; Rats; Rats, Sprague-Dawley; RNA, Messenger; Transforming Growth Factor beta

Dietary protein restriction has been shown to slow the rate of loss of kidney function in humans with progressive glomerulosclerosis due to glomerulonephritis or diabetes mellitus. A central feature of glomerulosclerosis is the pathological accumulation of extracellular matrix within the diseased glomeruli. Transforming growth factor beta 1 (TGF-beta 1) is known to have widespread regulatory effects on extracellular matrix and has been implicated as a major cause of increased extracellular matrix synthesis and buildup of pathological matrix within glomeruli in experimental glomerulonephritis. In the present study, it is shown that administration of a low protein diet to rats rapidly reduces the elevated expression of TGF-beta 1 mRNA and TGF-beta 1 protein that is known to occur within glomeruli after induction of glomerulonephritis. Compared to a normal protein diet, glomerulonephritic rats receiving the low protein diet did not develop an increase in glomerular extracellular matrix and showed significantly less proteinuria. Glomeruli isolated from glomerulonephritic rats fed the normal protein diet showed a marked increase in proteoglycan synthesis on day 7 of disease and were demonstrated to be secreting increased amounts of TGF-beta 1 into the medium, whereas glomeruli at the same point in time isolated from rats on a low protein diet showed no increase in proteoglycan production or TGF-beta 1 secretion. These results suggest that a mechanism of the rapid therapeutic effect of a low protein diet on experimental glomerulonephritis is through suppression of TGF-beta 1 expression and prevention of the induction of extracellular matrix synthesis within the injured glomeruli.

Topics: Animals; Blotting, Northern; Dietary Proteins; Extracellular Matrix; Fluorescent Antibody Technique; Gene Expression; Glomerulonephritis; Kidney Glomerulus; Proteinuria; Proteoglycans; Rats; Rats, Inbred Strains; RNA, Messenger; Transforming Growth Factor beta