3-nitrotyrosine and Kidney-Diseases

This study aims to determine the potential protective effects of ferulic acid against cisplatin-induced nephrotoxicity and to compare its effect with curcumin, a well-known protective agent against cisplatin- induced toxicity in rats. Administration of cisplatin resulted in high BUN (Blood Urea Nitrogen), creatinine, MDA (Malondialdehyde), MPO (Myeloperoxidase), TOS (Total Oxidative Status), PtNT (Protein Nitrotyrosine) levels (p<0.05). Histological observations showed abnormal morphology of kidney; in addition with appearance of TUNEL positive cells indicating apoptosis in cisplatin administered group. HO-1 (Heme Oxygenase-1) levels measured by RT-PCR (Real Time Polymerase Chain Reaction), and TAS (Total Antioxidative Status) revealed antioxidant depletion due to cisplatin toxicity in animals (p<0.05). All parameters showed improvement in groups treated with ferulic acid (p<0.05). Ferulic acid treatment was found significant in preventing oxidative stress, increasing antioxidative status and regaining histological parameters to normal, indicating nephroprotective and antioxidant effects of this phenolic compound.

Topics: Animals; Blood Urea Nitrogen; Cisplatin; Coumaric Acids; Curcumin; Heme Oxygenase (Decyclizing); Kidney; Kidney Diseases; Male; Malondialdehyde; Peroxidase; Protective Agents; Rats, Wistar; RNA, Messenger; Tyrosine

Cisplatin (CP) is a potent and widely used chemotherapeutic agent. However, the clinical benefits of CP are compromised because it elicits nephrotoxicity and ototoxicity. In this study, we investigated the nephroprotective effects of the phytochemical genipin (GP) isolated from the gardenia (Gardenia jasminoides) fruit, using a murine model of CP-induced nephropathy. GP pretreatment attenuated the CP-induced renal tissue injury by diminishing the serum blood urea nitrogen, creatinine, and cystatin C levels, as well as those of kidney injury molecule-1. In addition, GP attenuated the CP-induced oxidative/nitrative stress by suppressing the activation of NADPH oxidase, augmenting the endogenous antioxidant defense system, and diminishing the accumulation of 4-hydroxynonenal and 3-nitrotyrosine in renal tissues. Furthermore, reduced levels of proinflammatory cytokines such as tumor necrosis factor-alpha and interleukin-1 beta indicated that CP-induced renal inflammation was mitigated upon the treatment with GP. GP also attenuated the CP-induced activation of mitogen-activated protein kinases, excessive activities of caspase-3/7 and poly(ADP-ribose) polymerase, DNA fragmentation, and apoptosis. When administered 12h after the onset of kidney injury, GP showed a therapeutic effect by ameliorating CP-induced nephrotoxicity. Moreover, GP synergistically enhanced the CP-induced cell death of T24 human bladder cancer cells. Collectively, our data indicate that GP attenuated the CP-induced renal tissue injury by abrogating oxidative/nitrative stress and inflammation and by blocking cell death pathways, thereby improving the renal function. Thus, our results suggest that the use of GP may be a promising new protective strategy against cisplatin-induced nephrotoxicity.

Topics: Aldehydes; Animals; Antioxidants; Apoptosis; Blood Urea Nitrogen; Caspase 3; Caspase 7; Cell Line, Tumor; Cisplatin; Creatinine; Cystatin C; Cytokines; Hepatitis A Virus Cellular Receptor 1; Humans; Inflammation; Iridoids; Kidney; Kidney Diseases; Male; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinases; Oxidative Stress; Poly(ADP-ribose) Polymerases; Tyrosine

Hypertension is considered to be the most important risk factor for the development of cardiovascular diseases. Beside life-style risk factors, exposure to lead and mercury species are increasingly discussed as potential risk factors. Although there are a few previous studies, the underlying mechanism by which exposure to lead and mercury disturb blood pressure regulation is not currently understood. Potential mechanisms are oxidative stress production, kidney damage and activation of the renin-angiotensin system (RAS), all of which can interact to cause dysregulation of blood pressure. Male rats (Wistar) were exposed to lead, inorganic mercury, methylmercury or two mixtures of all three metals for four weeks through the drinking water. The two mixture ratios were based on ratios of known reference values or environmental exposure from the literature. To investigate the potential mechanism of actions, blood pressure was measured after four weeks and compared to plasma nitrotyrosine or reduced/oxidized glutathione levels in liver as markers for oxidative stress. Plasma renin and angiotensin II levels were used as markers for RAS activation. Finally, kidney function and injury were assessed via urinary and plasma creatinine levels, creatinine clearance and urinary kidney-injury molecule (KIM-1). While exposure to lead by itself increased oxidative stress and kidney damage along with blood pressure, inorganic mercury did not affect blood pressure or any end-point examined. Conversely, methylmercury instead increased RAS activation along with blood pressure. Surprisingly, when administered as mixtures, lead no longer increased oxidative stress or altered kidney function. Moreover, the mixture based on an environmental ratio no longer had an effect on blood pressure, while the reference value ratio still retained an increase in blood pressure. Based on our results, the prominent mechanism of action associated with the development of hypertension seems to be oxidative stress and kidney damage for lead, while increased RAS activation links methylmercury to hypertension, but these mechanisms along with hypertension disappear when metals are present in some mixtures.

Topics: Animals; Blood Pressure; Drinking Water; Glutathione; Hypertension; Kidney Diseases; Lead; Liver; Male; Mercury; Methylmercury Compounds; Oxidative Stress; Rats; Rats, Wistar; Renin-Angiotensin System; Tyrosine

Calcineurin inhibitors (CNIs) are effective immunosuppressive agents for the successful treatment of childhood steroid-resistant nephrotic syndrome (SRNS). Because these patients require long-term treatment, the identification of early markers of CNI-induced nephrotoxicity (CNIN) is imperative. The monitoring of CNI trough levels, serum creatinine, and glomerular filtration rate is not an accurate marker of CNIN. The present study has been undertaken to identify early markers of CNIN in SRNS patients. Twenty-four pediatric SRNS patients were included with paired renal biopsies, before initiation (time zero biopsy) and at least 1 year after CNI therapy (protocol renal biopsy) with standard dosage. Semiquantitative morphologic grading of the histologic features was done for assessing CNIN. Immunohistochemical markers for oxidative stress (nitrotyrosine [NT]), fibrogenic cytokine (transforming growth factor β1 [TGF-β1]), and endothelial injury (endothelial nitric oxide synthase [eNOS]) were evaluated. In addition, ultrastructural study was done to assess mitochondrial injury in endothelial and tubular epithelial cells. The protocol renal biopsies in comparison with time zero biopsies showed significant increase in glomerulosclerosis, juxtaglomerular apparatus hyperplasia, tubular atrophy, interstitial fibrosis, arteriolar hyalinosis, and smooth muscle vacuolization (P < .05 - P < .001). Significantly higher immunoexpression of eNOS (91.6%), NT (71%), and TGF-β1 (87.5%) was noted in posttreatment biopsies. Mean mitochondrial injury grade among post-CNI cases in endothelial cells and proximal tubular cells was 2.28 and 1.4, whereas in pre-CNI, it was 0.28 and 0.27, respectively. We propose that immunohistochemical overexpression of NT, eNOS, and TGF-β1 is an early marker of CNIN. Endothelial and proximal tubular mitochondrial injury may play an important role in the pathogenesis of CNIN.

Topics: Adolescent; Atrophy; Biomarkers; Biopsy; Calcineurin Inhibitors; Child; Child, Preschool; Early Diagnosis; Endothelial Cells; Female; Fibrosis; Humans; Hyperplasia; Immunohistochemistry; Immunosuppressive Agents; Infant; Kidney; Kidney Diseases; Kidney Tubules, Proximal; Male; Mitochondria; Nephrotic Syndrome; Nitric Oxide Synthase Type III; Oxidative Stress; Predictive Value of Tests; Time Factors; Transforming Growth Factor beta1; Treatment Outcome; Tyrosine; Up-Regulation

Recently, we demonstrated in female mice that protection against ANG II-induced hypertension and associated cardiovascular changes depend on cytochrome P-450 (CYP)1B1. The present study was conducted to determine if Cyp1b1 gene disruption ameliorates renal dysfunction and organ damage associated with ANG II-induced hypertension in female mice. ANG II (700 ng·kg(-1)·min(-1)) infused by miniosmotic pumps for 2 wk in female Cyp1b1(+/+) mice did not alter water consumption, urine output, Na(+) excretion, osmolality, or protein excretion. However, in Cyp1b1(-/-) mice, ANG II infusion significantly increased (P < 0.05) water intake (5.50 ± 0.42 ml/24 h with vehicle vs. 8.80 ± 0.60 ml/24 h with ANG II), urine output (1.44 ± 0.37 ml/24 h with vehicle vs. 4.30 ± 0.37 ml/24 h with ANG II), and urinary Na(+) excretion (0.031 ± 0.016 mmol/24 h with vehicle vs. 0.099 ± 0.010 mmol/24 h with ANG II), decreased osmolality (2,630 ± 79 mosM/kg with vehicle vs. 1,280 ± 205 mosM/kg with ANG II), and caused proteinuria (2.60 ± 0.30 mg/24 h with vehicle vs. 6.96 ± 0.55 mg/24 h with ANG II). Infusion of ANG II caused renal fibrosis, as indicated by an accumulation of renal interstitial α-smooth muscle actin, collagen, and transforming growth factor-β in Cyp1b1(-/-) but not Cyp1b1(+/+) mice. ANG II also increased renal production of ROS and urinary excretion of thiobarburic acid-reactive substances and reduced the activity of antioxidants and urinary excretion of nitrite/nitrate and the 17β-estradiol metabolite 2-methoxyestradiol in Cyp1b1(-/-) but not Cyp1b1(+/+) mice. These data suggest that Cyp1b1 plays a critical role in female mice in protecting against renal dysfunction and end-organ damage associated with ANG II-induced hypertension, in preventing oxidative stress, and in increasing activity of antioxidant systems, most likely via generation of 2-methoxyestradiol from 17β-estradiol.

Topics: Angiotensin II; Animals; Catalase; Cytochrome P-450 CYP1B1; Disease Models, Animal; Drinking; Estradiol; Female; Fibrosis; Genotype; Hypertension; Kidney; Kidney Diseases; Mice, Inbred C57BL; Mice, Knockout; NADPH Oxidases; Natriuresis; Oxidative Stress; Phenotype; Renin-Angiotensin System; Sex Factors; Superoxide Dismutase; Superoxides; Tyrosine; Urination

The cellular prion protein (PrPC), a protein most noted for its link to prion diseases, has been found to play a protective role in ischemic brain injury. To investigate the role of PrPC in the kidney, an organ highly prone to ischemia/reperfusion (IR) injury, we examined wild-type (WT) and PrPC knockout (KO) mice that were subjected to 30-min of renal ischemia followed by 1, 2, or 3 days of reperfusion. Renal dysfunction and structural damage was more severe in KO than in WT mice. While PrP was undetectable in KO kidneys, Western blotting revealed an increase in PrP in IR-injured WT kidneys compared to sham-treated kidneys. Compared to WT, KO kidneys exhibited increases in oxidative stress markers heme oxygenase-1, nitrotyrosine, and Nε-(carboxymethyl)lysine, and decreases in mitochondrial complexes I and III. Notably, phosphorylated extracellular signal-regulated kinase (pERK) staining was predominantly observed in tubular cells from KO mice following 2 days of reperfusion, a time at which significant differences in renal dysfunction, histological changes, oxidative stress, and mitochondrial complexes between WT and KO mice were observed. Our study provides the first evidence that PrPC may play a protective role in renal IR injury, likely through its effects on mitochondria and ERK signaling pathways.

Topics: Animals; Extracellular Signal-Regulated MAP Kinases; Heme Oxygenase-1; Kidney; Kidney Diseases; Mice; Mice, Knockout; Mitochondria; Oxidative Stress; Prions; Reperfusion Injury; Tyrosine

The aim of this study was to evaluate the effect of DTS-phytocompound on oxidant-antioxidant balance and protein damage in the kidneys of rats administered high doses of fructose. Adult male Wistar rats were divided into four groups. Group A received a control diet, whereas groups B and C were fed a high-fructose diet (60 g/100 g), the latter with additional DTS (50 mg/kg per day) for 60 days. Lipo- and nitro-peroxidation together with α-smooth muscle actin (α-SMA) expression in the glomerular and interstitial tissue of the kidneys were measured after 60 days. Fructose-fed rats showed significantly higher lipoperoxidation, 2,4-dinitrophenol and 3-nitrotyrosine protein adducts, and upregulation of α-SMA in the kidney. DTS significantly decreased such redox unbalance in renal tissue, while partially downregulating α-SMA (p<0.01). These data suggest the potential clinical benefit of DTS in protecting the kidneys from metabolic syndrome-associated changes; gender-related analysis is under way.

Topics: 2,4-Dinitrophenol; Animals; Antioxidants; Fructose; Kidney; Kidney Diseases; Lipid Peroxidation; Male; Metabolic Syndrome; Oxidation-Reduction; Oxidative Stress; Phytotherapy; Rats; Rats, Wistar; Tyrosine

In the present study, we tested whether polycystic kidney disease (PKD) is associated with renal tissue hypoxia and oxidative stress, which, in turn, contribute to the progression of cystic disease and hypertension. Lewis polycystic kidney (LPK) rats and Lewis control (Lewis) rats were treated with tempol (1 mmol/L in drinking water) from 3 to 13 weeks of age or remained untreated. The LPK rats developed polyuria, uraemia and proteinuria. At 13 weeks of age, LPK rats had greater mean arterial pressure (1.5-fold), kidney weight (sixfold) and plasma creatinine (3.5-fold) than Lewis rats. Kidneys from LPK rats were cystic and fibrotic. Renal hypoxia was evidenced by staining for pimonidazole adducts and hypoxia-inducible factor (HIF)-1α in cells lining renal cysts and upregulation of HIF-1α and its downstream targets vascular endothelial growth factor (VEGF), glucose transporter-1 (Glut-1) and heme oxygenase 1 (HO-1). However, total HO activity did not differ greatly between kidney tissue from LPK compared with Lewis rats. Renal oxidative and/or nitrosative stress was evidenced by ninefold greater immunofluorescence for 3-nitrotyrosine in kidney tissue from LPK compared with Lewis rats and a > 10-fold upregulation of mRNA for p47phox and gp91phox. Total renal superoxide dismutase (SOD) activity was sevenfold less and expression of SOD1 mRNA was 70% less in kidney tissue from LPK compared with Lewis rats. In LPK rats, tempol treatment reduced immunofluorescence for 3-nitrotyrosine and HIF1A mRNA while upregulating VEGF and p47phox mRNA expression, but otherwise had little impact on disease progression, renal tissue hypoxia or hypertension. Our findings do not support the hypothesis that oxidative stress drives hypoxia and disease progression in PKD.

Topics: Animals; Arterial Pressure; Cell Hypoxia; Creatinine; Cyclic N-Oxides; Disease Progression; Glucose Transporter Type 1; Heme Oxygenase (Decyclizing); Hemodynamics; Hypertension; Hypoxia-Inducible Factor 1, alpha Subunit; Kidney; Kidney Diseases; Male; Membrane Glycoproteins; NADPH Oxidase 2; NADPH Oxidases; Oxidative Stress; Polycystic Kidney Diseases; Rats; Rats, Inbred Lew; Spin Labels; Superoxide Dismutase; Superoxide Dismutase-1; Tyrosine; Vascular Endothelial Growth Factor A

3'-Nitrotyrosine (3NT) is a post-translational modification (PTM) of body fluids and tissues that is sustained by chronic inflammation and oxidative stress, two main clinical traits of chronic kidney disease (CKD). Despite this background, protein targets and their differential susceptibility to in vivo nitration remain almost completely unexplored in CKD. This study reports a first investigation of plasma nitroproteome in these patients, carried out by both immunorecognition and LC-MS/MS techniques. Plasma proteins of chronic and end-stage KD patients showed a higher burden of nitration than in healthy controls, but main nitration targets appeared to be the same in these populations. Immunoblotting data showed that uremic albumin is largely represented in the uremic nitroproteome together with fibrinogen chains (A, B and C), transferrin, α1-antitrypsin, complement factor D, haptoglobin, and IgG light and heavy chains. However, immunopurification and affinity chromatography experiments demonstrated that the relative content of 3NT on the albumin molecule was very low when compared with that of the remaining plasma proteins. The uremic nitroproteome was investigated using also plasma proteins obtained by in vivo ultrafiltration from patients treated with protein leaking or standard high-flux hemodialyzers. The study of these samples revealed the possibility to selectively remove protein nitration products during hemodialysis. Identification of intramolecular sites of nitration was preliminarily obtained in IgG chains isolated by 2D PAGE and assessed by bidimensional tandem mass spectrometry after chemoselective tagging. Further studies are needed to confirm at the molecular level the presence of nitrated Tyr residues in other proteins tentatively identified as nitration targets in this study and to explore the biological meaning of such a selective modification of plasma proteins by reactive nitrogen species in uremia and dialysis patients.

Topics: Aged; Aged, 80 and over; Amino Acid Sequence; Blood Proteins; Case-Control Studies; Chronic Disease; Electrophoresis, Gel, Two-Dimensional; Female; Humans; Kidney Diseases; Male; Middle Aged; Molecular Sequence Data; Protein Processing, Post-Translational; Proteome; Tandem Mass Spectrometry; Tyrosine

The ageing kidney exhibits slowly developing chronic kidney disease (CKD) and is associated with nitric oxide (NO) deficiency and increased oxidative stress. The impact of exercise on the ageing kidney is not well understood. Here, we determined whether 12 weeks of treadmill exercise can influence age-dependent CKD in old (22-24 months) Fisher 344 (F344) male rats by comparing sedentary (SED) and exercise (EX) trained rats; young (3 months) rats were also studied. In addition to renal structure and function, we assessed protein levels of various isoforms of the NO synthases (NOS) and superoxide dismutase (SOD) enzymes as well as markers of oxidative stress, in kidney cortex and medulla. Renal function as determined by plasma creatinine, proteinuria, and glomerular structural injury worsened with age and was unaffected by exercise. Ageing also increased the protein abundance of neuronal NOSβ and p22phox while decreasing extracellular (EC) and copper/zinc (CuZn) SOD, in kidney cortex and medulla. H(2)O(2) content and nitrotyrosine abundance also increased in the kidney with age. None of these age-related changes were altered with exercise. However, exercise did increase renal cortical endothelial (e)NOS and EC SOD in young rats. Data indicate that exercise-induced increases in eNOS and EC SOD seen in young rats are lost with age. We conclude that chronic exercise is ineffective in reversing age-dependent CKD in the male F344 rat.

Topics: Aging; Animals; Aorta; Chronic Disease; Hydrogen Peroxide; Kidney; Kidney Diseases; Male; NADPH Oxidases; Nitric Oxide Synthase Type I; Nitric Oxide Synthase Type III; Oxidative Stress; Physical Conditioning, Animal; Rats; Rats, Inbred F344; Superoxide Dismutase; Tyrosine

Cisplatin is an important chemotherapeutic agent; however, its nephrotoxicity limits its clinical use. Enhanced inflammatory response and oxidative/nitrosative stress seem to play a key role in the development of cisplatin-induced nephropathy. Activation of cannabinoid-2 (CB(2)) receptors with selective agonists exerts anti-inflammatory and tissue-protective effects in various disease models. We have investigated the role of CB(2) receptors in cisplatin-induced nephrotoxicity using the selective CB(2) receptor agonist HU-308 and CB(2) knockout mice. Cisplatin significantly increased inflammation (leukocyte infiltration, CXCL1/2, MCP-1, TNFalpha, and IL-1beta levels) and expression of adhesion molecule ICAM-1 and superoxide-generating enzymes NOX2, NOX4, and NOX1 and enhanced ROS generation, iNOS expression, nitrotyrosine formation, and apoptotic and poly(ADP-ribose) polymerase-dependent cell death in the kidneys of mice, associated with marked histopathological damage and impaired renal function (elevated serum BUN and creatinine levels) 3 days after the administration of the drug. CB(2) agonist attenuated the cisplatin-induced inflammatory response, oxidative/nitrosative stress, and cell death in the kidney and improved renal function, whereas CB(2) knockouts developed enhanced inflammation and tissue injury. Thus, the endocannabinoid system, through CB(2) receptors, protects against cisplatin-induced kidney damage by attenuating inflammation and oxidative/nitrosative stress, and selective CB(2) agonists may represent a promising novel approach to preventing this devastating complication of chemotherapy.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cannabinoids; Caspases; Cisplatin; In Situ Nick-End Labeling; Inflammation; Kidney Diseases; Kidney Function Tests; Lipid Peroxidation; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Oxidation-Reduction; Oxidative Stress; Peroxidase; Poly(ADP-ribose) Polymerases; Reactive Oxygen Species; Receptor, Cannabinoid, CB2; Tyrosine

Poly(ADP-ribose)polymerase (PARP) inhibitors prevent or alleviate diabetic nephropathy. This study evaluated the role for PARP-1 in diabetic kidney disease using the PARP-1-deficient mouse. PARP-1-/- and the wild-type (129S1/SvImJ) mice were made diabetic with streptozotocin, and were maintained for 12 weeks. Final blood glucose concentrations were increased ∼ 3.7-fold in both diabetic groups. PARP-1 protein expression (Western blot analysis) in the renal cortex was similar in non-diabetic and diabetic wild-type mice (100% and 107%) whereas all knockouts were PARP-1-negative. PARP-1 gene deficiency reduced urinary albumin (ELISA) and protein excretion prevented diabetes-induced kidney hypertrophy, and decreased mesangial expansion and collagen deposition (both assessed by histochemistry) as well as fibronectin expression. Renal podocyte loss (immunohistochemistry) and nitrotyrosine and transforming growth factor-β₁ accumulations (both by ELISA) were slightly lower in diabetic PARP-1-/- mice, but the differences with diabetic wild-type group did not achieve statistical significance. In conclusion, PARP-1-/- gene deficiency alleviates although does not completely prevent diabetic kidney disease.

Topics: Albuminuria; Animals; Blood Glucose; Blotting, Western; Diabetes Mellitus, Experimental; Enzyme-Linked Immunosorbent Assay; Hypertrophy; Immunohistochemistry; Kidney; Kidney Diseases; Male; Mice; Mice, Inbred Strains; Mice, Knockout; Podocytes; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerases; Transforming Growth Factor beta1; Tyrosine

We recently developed a rat model of cardiorenal failure that is characterized by severe left ventricular systolic dysfunction (LVSD) and low nitric oxide (NO) production that persisted after temporary low-dose NO synthase inhibition. We hypothesized that LVSD was due to continued low NO availability and might be reversed by supplementing NO. Rats underwent a subtotal nephrectomy and were treated with low-dose NO synthase inhibition with N(ω)-nitro-l-arginine up to week 8. After 3 wk of washout, rats were treated orally with either the long-acting, tolerance-free NO donor molsidomine (Mols) or vehicle (Veh). Cardiac and renal function were measured on weeks 11, 13, and 15. On week 16, LV hemodynamics and pressure-volume relationships were measured invasively, and rats were killed to quantify histological damage. On week 15, blood pressure was mildly reduced and creatinine clearance was increased by Mols (both P < 0.05). Mols treatment improved ejection fraction (53 ± 3% vs. 37 ± 2% in Veh-treated rats, P < 0.001) and stroke volume (324 ± 33 vs. 255 ± 15 μl in Veh-treated rats, P < 0.05). Rats with Mols treatment had lower end-diastolic pressures (8.5 ± 1.1 mmHg) than Veh-treated rats (16.3 ± 3.5 mmHg, P < 0.05) and reduced time constants of relaxation (21.9 ± 1.8 vs. 30.9 ± 3.3 ms, respectively, P < 0.05). The LV end-systolic pressure-volume relationship was shifted to the left in Mols compared with Veh treatment. In summary, in a model of cardiorenal failure with low NO availability, supplementing NO significantly improves cardiac systolic and diastolic function without a major effect on afterload.

Topics: Administration, Oral; Animals; Biomarkers; Cardiotonic Agents; Creatinine; Disease Models, Animal; Gene Expression Regulation; Kidney Diseases; Male; Molsidomine; Myocardial Contraction; Myocardium; Nephrectomy; Nitric Oxide; Nitric Oxide Donors; Nitroarginine; Rats; Rats, Inbred Lew; Stroke Volume; Time Factors; Tyrosine; Ventricular Dysfunction, Left; Ventricular Function, Left; Ventricular Pressure

This study investigated the protective effects of bicyclol against cisplatin-induced nephrotoxicity and the possible mechanisms in mice. Bicyclol (250 mg/kg, p.o., 5 days) showed significant protection as evidenced by the decrease of elevated serum creatine and blood urea nitrogen, and improvement of histopathological injury induced by cisplatin. The formation of kidney malondialdehyde with a concomitant reduction of reduced glutathione were also inhibited by bicyclol, while the activities of kidney superoxide dismutase, catalase and glutathione peroxidase were all increased, respectively. Bicyclol also inhibited the increase of kidney and serum nitric oxide induced by cisplatin. In addition, induction of induced nitric oxide synthase and nitrotyrosine were suppressed by bicyclol. Bicyclol suppressed cisplatin-induced extracelluar signal regulated kinases 1/2 and p38 mitogen-activated protein kinase activation in the kidney of mice. Results obtained demonstrate that bicyclol pre-administration can prevent the nephrotoxicity induced by cisplatin.

Topics: Animals; Antineoplastic Agents; Biphenyl Compounds; Cisplatin; Disease Models, Animal; Free Radical Scavengers; Glutathione; Kidney; Kidney Diseases; Male; Malondialdehyde; Mice; Mice, Inbred ICR; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinase Kinases; Nitric Oxide; Oxidative Stress; p38 Mitogen-Activated Protein Kinases; Tyrosine

Oxidative stress and apoptosis are important factors in the etiology of renal ischemia-reperfusion (I/R) injury. The present study tested the hypothesis that the cell-permeant SOD mimetic manganese(III) tetrakis(1-methyl-4-pyridyl)porphyrin (MnTMPyP) protects the kidney from I/R-mediated oxidative stress and apoptosis in vivo. Male Sprague-Dawley rats (175-220 g) underwent renal I/R by bilateral clamping of the renal arteries for 45 min followed by reperfusion for 24 h. To examine the role of reactive oxygen species (ROS) in renal I/R injury, a subset of animals were treated with either saline vehicle (I/R Veh) or MnTMPyP (I/R Mn) (5 mg/kg ip) 30 min before and 6 h after surgery. MnTMPyP significantly attenuated the I/R-mediated increase in serum creatinine levels and decreased tubular epithelial cell damage following I/R. MnTMPyP also decreased TNF-alpha levels, gp(91phox), and lipid peroxidation after I/R. Furthermore, MnTMPyP inhibited the I/R-mediated increase in apoptosis and caspase-3 activation. Interestingly, although MnTMPyP did not increase expression of the antiapoptotic protein Bcl-2, it decreased the expression of the proapoptotic genes Bax and FasL. These results suggest that MnTMPyP is effective in reducing apoptosis associated with renal I/R injury and that multiple signaling mechanisms are involved in ROS-mediated cell death following renal I/R injury.

Topics: Animals; Antioxidants; Apoptosis; Caspase 3; Creatinine; Gene Expression; Kidney; Kidney Diseases; Kidney Function Tests; Lipid Peroxidation; Male; Metalloporphyrins; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Superoxide Dismutase; Superoxides; Tumor Necrosis Factor-alpha; Tyrosine

The present study compared the immunolocalization of Kim-1, renal papillary antigen (RPA)-1, and RPA-2 with that of inducible nitric oxide synthase (iNOS) and nitrotyrosine in kidneys of gentamicin sulfate (Gen)- and cisplatin (Cis)-treated rats. The specificity of acute kidney injury (AKI) biomarkers, iNOS, and nitrotyrosine was evaluated by dosing rats with valproic acid (VPA). Sprague-Dawley (SD) rats were injected subcutaneously (sc) with 100 mg/kg/day of Gen for six or fourteen days; a single intraperitoneal (ip) dose of 1, 3, or 6 mg/kg of Cis; or 650 mg/kg/day of VPA (ip) for four days. In Gen-treated rats, Kim-1 was expressed in the epithelial cells, mainly in the S1/S2 segments but less so in the S3 segment, and RPA-1 was increased in the epithelial cells of collecting ducts (CD) in the cortex. Spatial expression of iNOS or nitrotyrosine with Kim-1 or RPA-1 was detected. In Cis-treated rats, Kim-1 was expressed only in the S3 segment cells, and RPA-1 and RPA-2 were increased in the epithelial cells of medullary CD or medullary loop of Henle (LH), respectively. Spatial expression of iNOS or nitrotyrosine with RPA-1 or RPA-2 was also identified. These findings suggest that peroxynitrite formation may be involved in the pathogenesis of Gen and Cis nephrotoxicity and that Kim-1, RPA-1, and RPA-2 have the potential to serve as site-specific biomarkers for Gen or Cis AKI.

Topics: Animals; Antigens; Cell Adhesion Molecules; Cisplatin; Gentamicins; Immunohistochemistry; Kidney; Kidney Diseases; Kidney Tubules, Proximal; Male; Nitric Oxide Synthase Type II; Photomicrography; Rats; Rats, Sprague-Dawley; Statistics, Nonparametric; Tyrosine; Valproic Acid

Cisplatin is a chemotherapeutic agent used in the treatment of several cancer tumors; however, nephrotoxicity has restricted its use. Reactive oxygen species and peroxynitrite, which is formed by the reaction between superoxide anion and nitric oxide (NO*), are implicated in cisplatin-induced nephrotoxicity. In contrast, both toxic and beneficial effects of NO* have been suggested in cisplatin-induced nephrotoxicity. Therefore, nowadays the role of NO* in this experimental model remains controversial. The aim of the present work was to elucidate the role of NO* in cisplatin-induced renal damage using N-[3-(aminomethyl)benzyl]acetamidine (1400W), a selective and irreversible inhibitor of iNOS. The mRNA levels of iNOS were increased in cisplatin-treated rats. The administration of 1400W reduced the cisplatin induced histological damage, renal dysfunction (increase in proteinuria and kidney injury molecule expression and decrease in creatinine clearance), tubulointerstitial infiltration, oxidative stress (increase in renal malondialdehyde and inmmunostaining for 4-hydroxy-2-nonenal) and nitrosative stress (immunostaining for 3-nitrotyrosine). In addition, the administration of 1400W was unable to modify systolic blood pressure in control rats. Our data demonstrate that selective iNOS inhibition reduces the cisplatin-induced nephrotoxicity and nitrosative stress which strongly suggest that in this experimental model (1) the NO* production is toxic and (2) iNOS is the main source of NO*.

Topics: Aldehydes; Amidines; Animals; Antineoplastic Agents; Benzylamines; Cisplatin; Disease Models, Animal; Enzyme Inhibitors; Gene Expression Regulation, Enzymologic; Kidney; Kidney Diseases; Male; Malondialdehyde; Nitric Oxide; Nitric Oxide Synthase Type II; Oxidative Stress; Rats; Rats, Wistar; RNA, Messenger; Tyrosine

Apoptosis has been shown to contribute to the development of acute and chronic renal failure. The antiapoptotic action of the heme oxygenase (HO) system may represent an important protective mechanism in kidney pathology. We examined whether the lack of HO-1 would influence apoptosis in clipped kidneys of two-kidney, one-clip (2K1C) rats. Five-day-old Sprague-Dawley rats were injected in the left ventricle with approximately 5 x 10(9) colony-forming units/ml of retrovirus containing rat HO-1 antisense (LSN-RHO-1-AS) or control retrovirus (LXSN). After 3 mo, a 0.25-mm U-shaped silver clip was placed around the left renal artery. Animals were killed 3 wk later. Clipping the renal artery in LSN-RHO-1-AS rats did not result in increased HO-1 expression. In contrast to LXSN animals, 2K1C LSN-RHO-1-AS rats showed increased expression of cyclooxygenase 2 (COX-2) and higher 3-nitrotyrosine (3-NT) content as well as increased expression of the proapoptotic protein Apaf-1 and caspase-3 activity. Clipping the renal artery in LXSN rats resulted in increased expression of the antiapoptotic proteins Bcl-2 and Bcl-xl, while clipping the renal artery in LSN-RHO-1-AS rats did not change Bcl-2 levels and decreased the levels of Bcl-xl. Treatment of LSN-RHO-1-AS rats with cobalt protoporphyrin resulted in induction of renal HO-1, which was accompanied by decreases in blood pressure, COX-2, 3-NT, and caspase-3 activity, and increased expression of anti-apoptotic molecules (Bcl-2, Bcl-xl, Akt and p-Akt) in the clipped kidneys. These findings underscore the prominent role of HO-1 in counteracting apoptosis in this 2K1C renovascular hypertension model.

Topics: Animals; Apoptosis; Blood Pressure; Blotting, Western; Cell Nucleus; Creatine; Cyclooxygenase 2; DNA Fragmentation; Gene Expression Regulation, Enzymologic; Genetic Vectors; Heme Oxygenase (Decyclizing); Heme Oxygenase-1; Hypertension, Renovascular; Kidney Diseases; Protoporphyrins; Rats; Rats, Sprague-Dawley; Renal Artery; Retroviridae; RNA, Antisense; Signal Transduction; Tyrosine

During renal ischemia-reperfusion (I/R) injury, apoptosis has been reported as a very important contributor to final kidney damage. The determinant role of cytoskeleton derangement in the development of apoptosis has been previously reported, but a clear description of the different mechanisms involved in this process has not been yet provided. The aim of our study was to know the role of peroxynitrite as an inductor of cytoskeleton derangement and apoptosis during renal I/R. Based on a rat kidney I/R model, using experiments in which both the actin cytoskeleton and peroxynitrite generation were pharmacologically manipulated, results indicate that the peroxynitrite produced during the I/R-derived oxidative stress state is able to provoke cytoskeleton derangement and apoptosis development. Thus control of peroxynitrite generation during I/R could be an effective tool for the improvement of cytoskeleton damage and reduction of apoptosis incidence in renal I/R injury.

Topics: Animals; Apoptosis; Blood Pressure; Blood Urea Nitrogen; Blotting, Western; Caspase 3; Cytoskeleton; In Situ Nick-End Labeling; Kidney Diseases; Kidney Function Tests; Male; Microscopy, Confocal; Peroxynitrous Acid; Rats; Rats, Wistar; Reperfusion Injury; Tyrosine

Previous studies have reported that isohumulones, the bitter compounds in beer, improve insulin resistance and hyperlipidemia in several animal models. In this study, we examined whether isohumulones ameliorate renal injury. Dahl salt-sensitive hypertensive rats were fed a low-salt diet (LS), a high-salt diet (HS) or a high-salt diet containing 0.3% isohumulones (HS+IH) for 4 weeks. Urinary nitrite/nitrate (NOx) excretion was measured at 4 weeks along with blood pressure and urinary protein excretion. Renal injury was evaluated histologically and reactive oxygen species (ROS) and nitric oxide (NO) production in the renal cortex was visualized. Oxidative stress and NO synthase (NOS) expression were evaluated by immunohistochemical staining and Western blot analysis. Mean blood pressure was significantly decreased in the HS+IH group compared with the HS group at 4 weeks (158.1+/-8.7 vs. 177.5+/-3.7 mmHg; p<0.05). Isohumulones prevented the development of proteinuria in the HS+IH group compared with the HS group at 2 weeks (61.7+/-26.8 vs. 117.2+/-9.8 mg/day; p<0.05). Glomerulosclerosis and interstitial fibrosis scores were significantly decreased in the HS+IH group compared with the HS group (0.61+/-0.11 vs. 1.55+/-0.23, 23.7+/-6.8 vs. 36.1+/-3.5%; p<0.05 for both). In the HS group, increased ROS and decreased NO were observed in glomeruli in vivo. Isohumulones reduced the ROS production, leading to the restoration of bioavailable NO. Urinary NOx excretion was significantly increased in the HS+IH group compared with the HS group. Furthermore, renal nitrotyrosine was increased in the HS group compared with the LS group, and this effect was prevented by isohumulones. Renal NOS expression did not differ among the three groups. These results suggest that isohumulones may prevent the progression of renal injury caused by hypertension via an anti-oxidative effect.

Topics: Animals; Antioxidants; Blood Pressure; Blotting, Western; Cyclopentanes; Humulus; Hypertension; Kidney Diseases; Nitrates; Nitric Oxide; Nitric Oxide Synthase; Nitrites; Oxidative Stress; Proteinuria; Rats; Rats, Inbred Dahl; Reactive Oxygen Species; Sodium Chloride; Tyrosine

Endothelial dysfunction is a key event in the development of renovascular complications in the metabolic syndrome. The aim of this study was to elucidate the pathogenetic mechanisms involved in renovascular injuries in the Zucker obese rat, a model of the metabolic syndrome, and to examine the therapeutic effects of pioglitazone, a thiazolidinedione. Obese rats fed high-protein diet (OHP) for 12 weeks exhibited nephropathy and endothelial dysfunction, which were improved by pioglitazone. Accumulation of nitrotyrosine, a tracer of nitrative stress, was increased in aorta of the OHP group. The mRNA expressions of NADPH oxidase components and inducible nitric oxide synthase in the aorta were enhanced in the OHP group. Pioglitazone reduced nitrotyrosine in the aorta of the OHP group, inhibiting the augmented expression levels of both. These results suggest that nitrative stress could cause endothelial dysfunction in the rat model of metabolic syndrome with nephropathy, and that pioglitazone ameliorates these injuries, presumably by reducing nitrative stress.

Topics: Animals; Endothelium, Vascular; Kidney Diseases; Kidney Glomerulus; Male; Metabolic Syndrome; NADPH Oxidases; Obesity; Pioglitazone; Polymerase Chain Reaction; Rats; Rats, Zucker; RNA, Messenger; Thiazolidinediones; Tyrosine; Vasodilation

Glycerol-induced renal lesions can have many causes, including increased oxidative stress and inflammation. Resveratrol, a polyphenolic phytoalexin found in grapes and red wine, is an antioxidant agent with anti-inflammatory effects. In the present study, we investigated the possible protective effect of resveratrol on glycerol-induced nephrotoxicity. Male Wistar rats were injected intramuscularly with 8 ml/kg of either 50% glycerol (n=18), glycerol+resveratrol (n=22), 0.15 M saline (n=14), saline+carboxymethylcellulose (n=10) or saline+resveratrol (n=8). The rats were killed 3 days after the injections, at which time the kidneys were removed for histological and immunohistochemical studies and lipid peroxidation determination. Blood and urine samples were collected in order to quantify sodium and creatinine. The results of the histological and immunohistochemical studies were scored according to the extent of damage and immunostaining, respectively, in the cortical tubulointerstitium. Lipid peroxidation was estimated by measuring malondialdehyde in renal tissue samples collected from control rats and glycerol-injected rats. By postinjection day 3, glycerol-only treated rats presented increases in plasma creatinine levels, as well as in fractional excretion of sodium and potassium (P<0.001). These increases were less pronounced in glycerol+resveratrol-treated rats (P<0.05). Cortical expression of macrophages, lymphocytes, nuclear factor-kappa B, heme oxygenase-1 and nitrotyrosine was greater in glycerol-treated rats than in controls (P<0.001). In addition, the histological findings for glycerol-treated rats were characteristic of acute tubular necrosis. Resveratrol attenuated all of these alterations (P<0.001). We conclude that resveratrol ameliorates glycerol-induced renal injury by suppressing the inflammatory process and by inhibiting lipid peroxidation.

Topics: Animals; Antioxidants; Blotting, Western; Glycerol; Heme Oxygenase-1; Immunohistochemistry; Kidney Cortex; Kidney Diseases; Kidney Function Tests; Lipid Peroxidation; Lymphocytes; Macrophages; Male; Malondialdehyde; NF-kappa B; Rats; Rats, Wistar; Resveratrol; Stilbenes; Tyrosine

Oxidative and nitrosative stress have been involved in gentamicin-induced nephrotoxicity. The purpose of this work was to study the effect of S-allylmercaptocysteine, a garlic derived compound, on gentamicin-induced oxidative and nitrosative stress and nephrotoxicity. In addition, the in vitro reactive oxygen species scavenging properties of S-allylmercaptocysteine were studied.. S-allylmercaptocysteine was able to scavenge hydroxyl radicals and singlet oxygen in vitro. In rats treated with gentamicin (70 mg/Kg body weight, subcutaneously, every 12 h, for 4 days), renal oxidative stress was made evident by the increase in protein carbonyl content and 4-hydroxy-2-nonenal, and the nitrosative stress was made evident by the increase in 3-nitrotyrosine. In addition, gentamicin-induced nephrotoxicity was evident by the: (1) decrease in creatinine clearance and in activity of circulating glutathione peroxidase, and (2) increase in urinary excretion of N-acetyl-beta-D-glucosaminidase, and (3) necrosis of proximal tubular cells. Gentamicin-induced oxidative and nitrosative stress and nephrotoxicity were attenuated by S-allylmercaptocysteine treatment (100 mg/Kg body weight, intragastrically, 24 h before the first dose of gentamicin and 50 mg/Kg body weight, intragastrically, every 12 h, for 4 days along gentamicin-treatment).. In conclusion, S-allylmercaptocysteine is able to scavenge hydroxyl radicals and singlet oxygen in vitro and to ameliorate the gentamicin-induced nephrotoxicity and oxidative and nitrosative stress in vivo.

Topics: Aldehydes; Animals; Biomarkers; Body Weight; Carboxylic Acids; Cysteine; Dinitrophenols; Energy Intake; Free Radical Scavengers; Gentamicins; Hydroxyl Radical; Immunohistochemistry; Kidney Cortex; Kidney Diseases; Kidney Glomerulus; Kidney Tubules, Proximal; Male; Oxidation-Reduction; Oxidative Stress; Proteins; Rats; Rats, Wistar; Reactive Oxygen Species; Tyrosine; Urine

Oxidative stress is involved in cisplatin-nephrotoxicity. However, it has not completely established if reactive nitrogen species and nitrosative stress are involved in this experimental model. The purpose of this work was to study the role of peroxynitrite, a reactive nitrogen specie, in cisplatin-nephrotoxicity using the compound 5,10,15,20-tetrakis (4-sulfonatophenyl) porphyrinato iron (III) (FeTPPS), a soluble complex able to metabolize peroxynitrite.. In rats treated with cisplatin (a single intraperitoneal dose of 7.5 mg/kg body weight), renal nitrosative stress was made evident by the increase in 3-nitrotyrosine on day 3. In addition, cisplatin-induced nephrotoxicity was evident by the histological damage of proximal tubular cells and by the increase in (a) serum creatinine, (b) blood urea nitrogen, and (c) urinary excretion of N-acetyl-beta-D-glucosaminidase and total protein. Cisplatin-induced nitrosative stress and nephrotoxicity were attenuated by FeTPPS-treatment (15 mg/kg body weight, intraperitoneally, every 12 hours for 3 days).. Nitrosative stress is involved in cisplatin-induced nephrotoxicity in rats. Our data suggest that peroxynitrite is involved, at least in part, in cisplatin-induced nephrotoxicity and protein nitration.

Topics: Animals; Body Weight; Catalysis; Cisplatin; Glomerular Mesangium; Kidney Diseases; Kidney Tubules; Male; Metalloporphyrins; Peroxynitrous Acid; Rats; Rats, Wistar; Reactive Nitrogen Species; Tyrosine; Urine

An impairment of nitric oxide (NO) bioavailability and/or metabolism may contribute to the excessive incidence of atherosclerotic complications observed in haemodialysis (HD) patients. Recent evidence indicates that NO metabolism involves a family of NO-related molecules that have not yet been explored in such patients. The aim of our study was to determine the plasma levels of S-nitrosothiol and nitrotyrosine in chronic HD patients, and to evaluate potential factors influencing their levels.. Plasma levels of S-nitrosothiols and nitrotyrosine were determined in 22 non-smoking HD patients and 12 healthy control subjects, together with albumin, homocysteine, haemoglobin, highly sensitive C-reactive protein (hsCRP) and various components of the oxidant-antioxidant system at the plasma and erythrocyte levels.. While plasma nitrosothiol levels were significantly higher in HD patients than in controls (2.25 +/- 1.17 vs 0.45 +/- 0.45 micromol/l, respectively, P < 0.0001), nitrotyrosine levels were not different. HD patients also exhibited a marked deficit of ascorbate and low plasma glutathione peroxidase activity. An inverse relationship was found between plasma S-nitrosothiol and blood haemoglobin in HD patients (P < 0.005). No direct relationship was observed between plasma S-nitrosothiol levels and any of the oxidative stress markers, or hsCRP levels.. This study demonstrates high plasma S-nitrosothiol levels in HD patients, which are partially related to low blood haemoglobin concentrations. The pathophysiological significance of this elevation remains to be elucidated. A possible protective role against nitrosative stress is suggested in presence of normal plasma nitrotyrosine levels in such patients.

Topics: Biomarkers; C-Reactive Protein; Erythrocytes; Female; Glutathione; Glutathione Peroxidase; Humans; Iron; Kidney Diseases; Kidney Failure, Chronic; Male; Middle Aged; Nitric Oxide; Reference Values; Renal Dialysis; S-Nitrosothiols; Transferrin; Tyrosine

Hyperhomocysteinemia is associated with endothelial dysfunction, although the underlying mechanism is unknown. Previous studies have shown that nitric oxide (NO) plays an important role in the regulation of systemic and renal hemodynamics. This study investigated whether hyperhomocysteinemia induces renal oxidative stress and promotes renal dysfunction involving disturbances of the NO-pathway in Wistar rats. During 8 wk, control (C) and hyperhomocysteinemic (HYC) groups had free access to tap water and homocysteine-thiolactone (HTL, 50 mg/kg per d), respectively. At 8 wk, plasma homocysteine concentration, renal superoxide anion (O(2)), nitrotyrosine, and nitrite+nitrate levels, and renal function were measured. To assess NO involvement, the responses to L-Arginine (L-Arg, 300 mg/kg) and N(G)-nitro-L-arginine-methyl-ester (L-NAME, 20 microg/kg per min for 60 min) were analyzed. The HYC group showed higher homocysteine concentration (7.6 +/- 1.7 versus 4.9 +/- 1.0 micromol/L; P < 0.001), (O(2) production (157.92 +/- 74.46 versus 91.17 +/- 29.03 cpm. 10(3)/mg protein), and nitrite+nitrate levels (33.4 +/- 5.1 versus 11.7 +/- 4.3 micro mol/mg protein; P < 0.001) than the control group. Western blot analyses showed a nitrotyrosine mass 46% higher in the HYC group than in the controls. Furthermore, the HYC group showed lower GFR, renal plasma flow (RPF), and higher renal vascular resistance (RVR) than the controls. After L-Arg administration, the responses of GFR, RPF, and RVR were attenuated by 36%, 40%, and 50%, respectively; after L-NAME, the responses of RPF and RVR were exaggerated by 79% and 112%, respectively. This suggests a reduced NO bioavailability to produce vasodilation and an enhanced sensitivity to NO inhibition. In conclusion, hyperhomocysteinemia induces oxidative stress, NO inactivation, and renal dysfunction involving disturbances on the NO-pathway.

Topics: Animals; Cyclic GMP; Homocysteine; Hyperhomocysteinemia; Kidney Diseases; Male; Nitric Oxide; Oxidative Stress; Rats; Rats, Wistar; Renal Circulation; Thiobarbituric Acid Reactive Substances; Tyrosine

Generation of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) may contribute to renal ischemia/reperfusion (I/R) injury. The aim of this study was to investigate the effects of GW274150, a novel, highly selective, potent and long-acting inhibitor of iNOS activity in rat and mouse models of renal I/R.. Rats were administered GW274150 (5 mg/kg intravenous bolus administered 30 minutes prior to I/R) and subjected to bilateral renal ischemia (45 minutes) followed by reperfusion (6 hours). Serum and urinary indicators of renal dysfunction, tubular and reperfusion injury were measured, specifically, serum urea, creatinine, aspartate aminotransferase (AST) and N-acetyl-beta-d-glucosaminidase (NAG) enzymuria. In addition, renal sections were used for histologic scoring of renal injury and for immunologic evidence of nitrotyrosine formation and poly [adenosine diphosphate (ADP)-ribose] (PAR). Nitrate levels were measured in rat plasma using the Griess assay. Mice (wild-type, administered 5 mg/kg GW274150, and iNOS-/-) were subjected to bilateral renal ischemia (30 minutes) followed by reperfusion (24 hours) after which renal dysfunction (serum urea, creatinine), renal myeloperoxidase (MPO) activity and malondialdehyde (MDA) levels were measured.. GW274150, administered prior to I/R, significantly reduced serum urea, serum creatinine, AST, and NAG indicating reduction of renal dysfunction and injury caused by I/R. GW274150 reduced histologic evidence of tubular injury and markedly reduced immunohistochemical evidence of nitrotyrosine and PAR formation, indicating reduced peroxynitrite formation and poly (ADP-ribose) polymerase (PARP) activation, respectively. GW274150 abolished the rise in the plasma levels of nitrate (indicating reduced NO production). GW274150 also reduced the renal dysfunction in wild-type mice to levels similar to that observed in iNOS-/- mice subjected to I/R. Renal MPO activity and MDA levels were significantly reduced in wild-type mice administered GW274150 and iNOS-/- mice subjected to renal I/R, indicating reduced polymorphonuclear leukocyte (PMN) infiltration and lipid peroxidation.. These results suggest that (1). an enhanced formation of NO by iNOS contributes to the pathophysiology of renal I/R injury and (2). GW274150 reduces I/R injury of the kidney. We propose that selective inhibitors of iNOS activity may be useful against renal dysfunction and injury associated with I/R of the kidney.

Topics: Animals; Creatinine; Enzyme Inhibitors; Kidney; Kidney Diseases; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Peroxidase; Poly Adenosine Diphosphate Ribose; Rats; Rats, Wistar; Reperfusion Injury; Sulfides; Tyrosine; Urea

Heme oxygenase (HO) is the rate-limiting enzyme in the degradation of heme; its inducible isozyme HO-1 protects against some types of acute tissue injury. The expression and functional role of HO-1 in rats with renal injury induced by potassium dichromate (K(2)Cr(2)O(7)) was investigated in this work. Rats were studied 24 h after a single injection of K(2)Cr(2)O(7). To address the possible protective effect of HO-1 in this experimental model, this enzyme was induced by an injection of stannous chloride (SnCl(2)) 12 h before K(2)Cr(2)O(7) administration. The functional role of HO-1 in K(2)Cr(2)O(7) + SnCl(2)-treated animals was tested by inhibiting HO activity with an injection of zinc (II) protoporphyrin IX (ZnPP) 18 h before K(2)Cr(2)O(7). In K(2)Cr(2)O(7)-treated rats: (i) renal HO-1 content, measured by Western blot, increased 2.6-fold; and, (ii) renal nitrotyrosine and protein carbonyl content, markers of oxidative stress, increased 3.5- and 1.36-fold, respectively. Renal damage and oxidative stress were ameliorated and HO-1 content was increased in the K(2)Cr(2)O(7) + SnCl(2) group. The attenuation of renal injury and oxidative stress was lost by the inhibition of HO activity in K(2)Cr(2)O(7) + SnCl(2) + ZnPP-treated animals. Our data suggest that HO-1 overexpression induced by SnCl(2) is responsible for the attenuation of renal damage and oxidative stress induced by K(2)Cr(2)O(7).

Topics: Animals; Blotting, Western; Caustics; Creatinine; Enzyme Induction; Heme Oxygenase (Decyclizing); Heme Oxygenase-1; Kidney; Kidney Diseases; Male; Oxidative Stress; Potassium Dichromate; Protoporphyrins; Rats; Rats, Wistar; Tin Compounds; Tyrosine

Potential of sanguiin H-6, a component of Sanguisorbae Radix, to protect against oxidative damage in renal mitochondria and apoptosis mediated by peroxynitrite (ONOO(-)) was examined using a model in which rats were injected with lipopolysaccharide (LPS) and then subjected to renal ischemia followed reperfusion (LPS plus ischemia-reperfusion). Ischemia-reperfusion was achieved by occluding bilateral renal artery for 60 min and then releasing for 350 min. At 50 min after ischemia started, LPS was injected intravenously. LPS plus ischemia-reperfusion induced a large amount of 3-nitrotyrosine, an oxidative product of protein that is produced via ONOO(-) nitration, which was not detectable in normal group. Oxidative damage of mitochondria was indicated by an accumulated thiobarbituric acid (TBA)-reactive substance, glutathione (GSH) depletion and glutathione peroxidase (GSH-Px) inactivation in the mitochondria. Treatment of rats with sanguiin H-6 (10 mg/kg body weight/day) for 30 days prior to LPS plus ischemia-reperfusion attenuated the oxidative damage in the mitochondria. The amount of TBA-reactive substance was decreased and the GSH levels significantly increased as compared with that in control group. However, its effect on GSH-Px activity was much weaker. Apoptosis induced by LPS plus ischemia-reperfusion was detected by fluorescence staining, TdT-mediated dUTP-biotin nick end labeling and electrophoretic analysis. Sanguiin H-6 appeared to inhibit apoptosis, and this was associated with the suppression of caspase-3 activity. These beneficial effects of sanguiin H-6 against oxidative damage in mitochondria and apoptosis contributed to the improvement in renal function by reversing the elevated levels of blood urea nitrogen and creatinine caused by ONOO(-).

Topics: Animals; Blood Urea Nitrogen; Caspase 3; Caspases; Creatinine; Disease Models, Animal; DNA Fragmentation; Hydrolyzable Tannins; Ischemia; Kidney; Kidney Diseases; Lipopolysaccharides; Male; Mitochondria; Oxidative Stress; Peroxynitrous Acid; Rats; Rats, Wistar; Sanguisorba; Tannins; Tyrosine

The aim of this study was to investigate whether in vivo administration of a low, sub-lethal dose of lipoteichoic acid (LTA), a bacterial wall-fragment derived from the Gram-positive bacterium Staphylococcus aureus, protects the kidney against the renal dysfunction and injury caused by ischemia/reperfusion (I/R).. Male Wistar rats were administered LTA from S. aureus (1 mg/kg, IP). After 24 hours, rats were subjected to bilateral renal ischemia (45 min) followed by reperfusion (6 h). Serum and urinary markers were measured for the assessment of renal function, tubular and reperfusion-injury. Renal sections were used for histological grading of renal injury and for immunohistochemical localization of P-selectin, inducible nitric oxide synthase (iNOS) and nitrotyrosine (indicative of peroxynitrite formation). Kidney myeloperoxidase (MPO) activity and malondialdehyde (MDA) levels were measured for assessment of polymorphonuclear (PMN) cell infiltration and lipid peroxidation, respectively. Nitric oxide (NO) production was determined by measurement of plasma nitrite/nitrate levels.. LTA pretreatment significantly reduced renal dysfunction, tubular and reperfusion-injury caused by I/R of the kidney as well as histological evidence of renal injury. LTA also reduced the expression of P-selectin and kidney MPO activity associated with renal I/R. MDA levels were significantly reduced by LTA pretreatment suggesting a reduction in the lipid peroxidation and formation of reactive oxygen species (ROS). LTA pretreatment also markedly reduced both the expression of iNOS and the formation of nitrotyrosine associated with renal I/R. Although LTA significantly reduced plasma nitrite/nitrate levels associated with I/R, nitrite/nitrate levels remained at levels significantly higher than that measured from the plasma obtained from Sham-operated animals.. These data suggest, to our knowledge for the first time, that LTA pretreatment for 24 hours significantly reduces renal I/R injury. We propose that the mechanism of the protective effect involves reduction of the production of NO, ROS and peroxynitrite subsequent to reduced P-selectin and iNOS expression and PMN recruitment. However, although LTA pretreatment resulted in a reduction of iNOS expression and NO production, we hypothesize that the remaining significant levels of NO contribute to the beneficial actions provided by LTA.

Topics: Animals; Antioxidants; Cyclic N-Oxides; Kidney Diseases; Kidney Tubules; Lipopolysaccharides; Male; Malondialdehyde; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; P-Selectin; Peroxidase; Rats; Rats, Wistar; Reperfusion Injury; Spin Labels; Staphylococcus aureus; Teichoic Acids; Tyrosine

Here we investigate the effects of the stable, water-soluble nitroxyl radical, TEMPONE, on renal dysfunction and injury caused by ischemia/reperfusion (I/R) of the rat kidney in vivo. TEMPONE significantly improved both glomerular and tubular function (serum urea, creatinine, creatinine clearance, and fractional excretion of Na(+)) in a dose-dependent manner and significantly attenuated the reperfusion-injury associated with I/R (urinary N-acetyl-beta-D-glucosaminidase, aspartate aminotransferase, assessment of renal histology). TEMPONE also markedly reduced the immunohistochemical evidence of the formation of nitrotyrosine and poly(ADP-ribose), indicating reduction of nitrosative and oxidative stress, respectively. The latter was reflected in vitro, where TEMPONE significantly reduced cellular injury of primary cultures of rat renal proximal tubular (PT) cells caused by hydrogen peroxide in a dose-dependent manner. Importantly, in contrast to its in vivo metabolite TEMPOL (which also provided protective effects against renal I/R and oxidative stress of PT cells), TEMPONE reduced renal dysfunction and injury without causing a significant reduction in blood pressure upon administration. These results suggest, for the first time, that TEMPONE can reduce the renal dysfunction and injury caused by I/R and the injury caused to PT cells by oxidative stress without producing the adverse cardiovascular effects observed when using other nitroxyl radicals.

Topics: Animals; Coloring Agents; Dose-Response Relationship, Drug; Hydrogen Peroxide; Immunohistochemistry; Kidney; Kidney Diseases; Male; Mice; Nitrogen; Oxidative Stress; Poly Adenosine Diphosphate Ribose; Poly(ADP-ribose) Polymerases; Rats; Rats, Wistar; Reactive Oxygen Species; Reperfusion Injury; Tetrazolium Salts; Thiazoles; Triacetoneamine-N-Oxyl; Tyrosine; Urine

In previous studies of transgenic sickle cell mice, increased renal expression of inducible nitric oxide synthase (iNOS) and endothelial cell isoform of NOS (EcNOS) was found by Western blot and immunohistochemistry. In addition, putative evidence of peroxynitrite (ONOO-) formation was found in the form of positive immunostaining and immunoblot for nitrotyrosine. Apoptosis was also detected by DNA strand breakage and TUNEL assay. The present study was carried out to examine the role of NO/ONOO- in mediating renal tubular cell apoptosis in sickle cell mouse kidneys.. Mercaptoethylguanidine (MEG), a compound that selectively inhibits iNOS and also is a scavenger of ONOO-, was administered intraperitoneally over a five-day period to control and betas mice. Immunohistochemistry of iNOS and nitrotyrosine, DNA electrophoresis, ApoTACS assay for apoptosis, and Western blot of poly(ADP-ribose) polymerase (PARP) were carried out.. MEG administration virtually eliminated renal immunostaining of iNOS and nitrotyrosine and prevented DNA strand breakage. In addition, Western blot analysis of PARP, a nuclear DNA-reparative enzyme activated in response to DNA strand breakage, was found to be cleavaged in hypoxic betas mice, but was partially protected in MEG-treated betas hypoxic mice. Finally, apoptosis was markedly reduced by MEG in betas hypoxic mice.. These observations provide evidence that NO and/or ONOO- are responsible for initiating cell damage, which leads to apoptosis in sickle cell mouse kidneys.

Topics: Alanine Transaminase; Anemia, Sickle Cell; Animals; Apoptosis; Aspartate Aminotransferases; Blotting, Western; Cell Hypoxia; DNA Fragmentation; Electrophoresis, Agar Gel; Enzyme Inhibitors; Guanidines; Immunohistochemistry; In Situ Nick-End Labeling; Kidney Diseases; Kidney Tubules; Mice; Mice, Inbred C57BL; Mice, Transgenic; Nitrates; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Poly(ADP-ribose) Polymerases; Tyrosine