transforming-growth-factor-beta and Hydronephrosis

Many recent clinical and experimental studies have clearly demonstrated that one of the initial events taking place in the process of progressive renal injury is monocytic infiltration of the glomerular and tubulointerstitial compartments. In this report, experimental data supporting the role of the infiltrating renal macrophage (M phi) as a mediator of interstitial fibrosis during the course of obstructive nephropathy will be reviewed as it pertains to the unilateral ureteral obstruction model in the rat. The central pathobiologic theme drawn on data from this model is that fibrogenic cytokines, especially transforming growth factor-beta, are, in part, M phi-derived and represent pivotal links between the initial postobstructive renal inflammation and the late development of renal scarring. The tubular epithelium, as a consequence of the mechanical disturbance produced by ureteral obstruction, may elaborate a host of M phi chemoattractant moieties. Many substances can be released by these infiltrating M phi; however, our studies have focused on transforming growth factor-beta 1. Transforming growth factor-beta is an important regulator of extracellular matrix, through its direct effects and modulation of other growth factors to maintain matrix homeostasis. We propose that the markedly increased expression of transforming growth factor-beta 1 following ureteral ligation, as detected by a number of laboratories, induces a profibrogenic state and initiates a cascade of dysregulatory events, including the upregulation of tissue inhibitors of metalloproteinase. Transforming growth factor-beta 1 also may serve as a potent stimulus for the modulation of quiescent interstitial fibroblasts into myofibroblasts. From a therapeutic standpoint, targeting these early cellular and molecular events may be extremely important in interrupting the interstitial fibrotic response to long-term obstructive uropathy.

Topics: Animals; Cicatrix; Disease Models, Animal; Fibroblasts; Fibrosis; Glycoproteins; Hydronephrosis; Kidney; Kidney Diseases; Ligation; Macrophages; Metalloendopeptidases; Rats; Tissue Inhibitor of Metalloproteinases; Transforming Growth Factor beta; Ureter

We evaluated urinary transforming growth factor-beta1 (TGF-beta1) concentration in children with upper urinary tract obstruction as a potential tool for supporting the diagnosis of clinically significant obstruction.. Renal pelvic and bladder urine samples were obtained for analysis from 30 patients a median of 5 months old who underwent surgery for obstruction at the ureteropelvic (29) and ureterovesical (1)junctions. Urinary TGF-beta1 concentration was measured using a quantitative sandwich enzyme-linked immunoassay technique. Bladder urine TGF-beta1 in patients with obstruction was compared with that in controls. In addition, we compared renal pelvic and bladder urine TGF-beta1 in patients with obstruction.. Mean bladder urine TGF-beta1 plus or minus standard error of mean was 4-fold higher in patients with upper tract obstruction than in controls (195 +/- 29 versus 47 +/- 7 pg./mg. creatinine, p <0.001). In the obstructed group mean TGF-beta1 in the renal pelvic urine was 378 +/-86 pg./mg. creatinine, or twice that of the bladder urine (p = 0.02).. Bladder urine TGF-beta1 in patients with upper urinary tract obstruction is significantly elevated compared with that in controls. To our knowledge our study is the first to identify a bladder urinary marker that correlates with upper urinary tract obstruction with greater than 90% sensitivity. Measuring TGF-beta1 in a voided bladder urine sample may provide an objective and noninvasive test for assisting in the diagnosis of upper urinary tract obstruction.

Topics: Adolescent; Child; Child, Preschool; Female; Humans; Hydronephrosis; Infant; Male; Sensitivity and Specificity; Transforming Growth Factor beta

We want to study whether the degree of fibrosis in the mild and severe hydronephrosis is different, and whether the irrigation pressure will affect the fibrosis of the hydronephrosis.. Animal models of mild and severe hydronephrosis in the left kidney were established: 72 healthy C57BL/6 mice were randomly divided into nine groups (eight in each group). The N group was used as a control group, and 0 mmHg pressure perfusion was given. The M and S groups were used as mild and severe hydronephrosis groups, respectively. The mild and severe hydronephrosis groups were subdivided into eight subgroups, M0-M3 and S0-S3. Among them, groups 0, 1, 2, and 3 were perfused with 0 mmHg, 20 mmHg, 60 mmHg, and 100 mmHg, respectively. We investigated the effects of irrigation pressures on renal fibrosis in mild (group M) and heavy (group S) hydronephrosis by quantitative real-time polymerase chain reaction, Western blot analysis, Masson staining and immunohistochemistry staining in mouse models.. Compared with group N, EMT and ECM deposits were significantly aggravated in both the mild and severe hydronephrosis groups, TGF-β signaling pathway-related molecules significantly changed too. In terms of ECM deposition, S2 and S3 are significantly increased compared to S0.The EMT of M2 and M3 changed significantly compared with M0; the EMT of S1, S2 and S3 changed significantly compared with S0.The molecules related to TGF-β signaling pathway also changed: M0 and S0 changed significantly compared with N; M1, M2 and M3 changed significantly compared with M0; compared with S0, S1, S2 and S3 changed significantly.. Compared with mild hydronephrosis, renal fibrosis in severe hydronephrosis is more severe and its tolerance to perfusion pressure is lower. These changes may be related to the TGF-β signalling pathway.

Topics: Animals; Cadherins; Disease Models, Animal; Epithelial-Mesenchymal Transition; Fibrosis; Hydronephrosis; Kidney; Kidney Diseases; Mice; Mice, Inbred C57BL; Severity of Illness Index; Signal Transduction; Smad Proteins; Transforming Growth Factor beta; Urinary Tract

Angiotensin (Ang) II type 1 receptor blockers have demonstrated beneficial effects beyond blood pressure control in the treatment of chronic kidney disease. There is clinical evidence that telmisartan is more effective than losartan in reducing proteinuria in hypertensive patients with diabetic nephropathy, because it is a partial agonist of peroxisome-proliferator activated receptor-γ (PPARγ), as well as an Ang II type 1 receptor blocker (AMADEO Study [A comparison of telMisartan versus losArtan in hypertensive type 2 DiabEtic patients with Overt nephropathy]). In this study, we examined the role of PPARγ activation in the renal protective actions of telmisartan using Ang II type 1 receptor-deficient mice. Renal injury was induced in Ang II type 1 receptor-deficient mice by producing unilateral ureteral obstruction, which exhibited severe renal interstitial fibrosis and inflammation. In these mice, telmisartan prevented hydronephrosis induced by unilateral ureteral obstruction more strongly than did losartan. Importantly, the prevention of renal atrophy and fibrosis by telmisartan was significantly attenuated by GW9662, a PPARγ antagonist. Interestingly, the downstream effector of PPARγ activation by telmisartan is hepatocyte growth factor (HGF), a well-known antifibrotic factor, because renal HGF expression was significantly increased by telmisartan, and a neutralizing antibody against HGF diminished the renal protective action of telmisartan. These beneficial changes by telmisartan were associated with a decrease in the expression of transforming growth factor-β1 and other proinflammatory and profibrotic cytokine genes through PPARγ/HGF activation. Our findings provide evidence of organ protective actions of telmisartan through the PPARγ/HGF pathway, independent of Ang II type 1 receptor blockade. Further development of the next generation of Ang II type 1 receptor blockers with added organ protective actions, such as PPARγ activation, might provide new beneficial drugs to treat renal and cardiovascular diseases.

Topics: Angiotensin II Type 1 Receptor Blockers; Anilides; Animals; Antibodies; Benzimidazoles; Benzoates; Cells, Cultured; Disease Models, Animal; Fibroblasts; Hepatocyte Growth Factor; Hydronephrosis; Kidney; Losartan; Male; Mice; Mice, Knockout; PPAR gamma; Receptor, Angiotensin, Type 1; Signal Transduction; Telmisartan; Transforming Growth Factor beta; Ureteral Obstruction

Progressive renal fibrosis is the final common pathway leading to renal failure irrespective of the initiating cause. Clinical studies of renal fibrosis found that prominent mast cell accumulation correlated with worse outcomes. Mast cells are pluripotent innate immune cells that synthesize and secrete profibrotic mediators. Here we use mast cell-deficient (Kit(W-sh/W-sh)) mice to define a functional pathogenic role for these cells in the development of renal fibrosis. Intrarenal collagen deposition was significantly decreased in mast cell-deficient compared to wild-type mice 7 and 14 days after unilateral ureteric obstruction. The intrarenal expression of mRNAs for transforming growth factor-β, α-smooth muscle actin, chemokines, and renal macrophages and CD4(+) T cells were also decreased in mast cell-deficient mice. Reconstitution of the mast cell population in mast cell-deficient mice with wild-type bone marrow-derived mast cells restored the pattern and intensity of renal fibrosis to levels seen in wild-type mice following ureteric ligation. Interestingly, the mast cells were recruited, activated, and degranulated within 6 h of ureteric ligation. A mast cell stabilizer that impairs degranulation, disodium chromoglycate, significantly attenuated renal fibrosis following ureteric ligation in wild-type mice. Thus, mast cells promote renal fibrosis and their targeting may offer therapeutic potential in the treatment of renal fibrosis.

Topics: Actins; Animals; CD4-Positive T-Lymphocytes; Cell Degranulation; Cells, Cultured; Chemokines; Collagen; Cromolyn Sodium; Disease Models, Animal; Disease Progression; Fibrosis; Gene Expression Regulation; Hydronephrosis; Kidney; Kidney Diseases; Macrophages; Male; Mast Cells; Matrix Metalloproteinase 12; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mutation; Phenotype; Proto-Oncogene Proteins c-kit; Time Factors; Transforming Growth Factor beta; Ureteral Obstruction

• To compare the expressions of common fibrosis-relevant genes in hydronephrosis-induced fibrotic renal tissues and normal human renal tissues, thereby providing insights into the cellular and molecular mechanisms of renal fibrosis resulting from hydronephrosis.. • A total of 12 extensively fibrotic renal tissue samples from patients with hydronephrosis (H-group) and six normal renal tissue samples from patients who underwent nephrectomy for renal cell carcinoma (N-group), along with their clinical data, were collected at Renmin Hospital of Wuhan University in China between October 2005 and August 2007. • These tissue samples were compared for their transforming growth factor-β (TGF-β)/bone morphogenetic protein (BMP) pathway-related gene profiles using a real-time polymerase chain reaction (PCR) microarray. • Subsequently, reverse transcriptase-PCR assays were used to validate the expression changes of left-right determination factor (LEFTY), a gene of interest, at the mRNA level. • The different expression of LEFTY at the protein level was confirmed by western blotting and immunohistochemistry assays.. • The results showed that 49 genes were differently expressed in fibrotic renal tissues relative to normal control tissues. Among these genes, 25 were up-regulated and 24 were down-regulated. • LEFTY-B, one of the most markedly altered genes, was down-regulated 13.55-fold compared with N-group tissues. • RT-PCR showed that the LEFTY-A (6.05-fold down-regulated, P < 0.001) and LEFTY-B (12.5-fold down-regulated, P < 0.001) genes, two members of the LEFTY family in human tissues, were both significantly down-regulated in H-group tissues. • Similarly, down-regulations of LEFTY-A (0.25-fold vs N-group, P < 0.001) and LEFTY-B (0.20-fold vs N-group, P < 0.001) proteins were detected by western blotting (P < 0.001). • Immunohistochemical staining showed different distributions of LEFTY in the two tissue samples, and quantitative image analyses confirmed that LEFTY protein expression was lower in H-group tissues than in N-group tissues (P < 0.001).. • The gene and protein expressions of LEFTY were found to be down-regulated in extensively fibrotic renal tissues induced by hydronephrosis. • LEFTY may represent an ideal candidate for a therapeutic target for renal fibrosis.

Topics: Adult; Bone Morphogenetic Proteins; Down-Regulation; Female; Fibrosis; Humans; Hydronephrosis; Immunohistochemistry; Kidney; Left-Right Determination Factors; Male; Middle Aged; Nephrectomy; Polymerase Chain Reaction; Transforming Growth Factor beta

To investigate the effect of cyclooxygenase-2 (COX-2) inhibitor on the tissue damage and fibrosis in obstructed ureters, 80 rats were studied. Celecoxib, a COX-2 inhibitor, was administered to 40 rats at the dose of 10 mg/kg per day 1 day before unilateral ligation of ureters and every day thereafter. The others, receiving unilateral ligation of ureters only, served as controls. Eight rats from each group were sacrificed for examination on days 7, 14, 21, 28 and 42 after ligation, respectively. The expressions of COX-2, prostaglandin E(2) (PGE(2)), transforming growth factor-beta(1) (TGFbeta(1)), alpha-smooth muscle actin (alpha-SMA), proliferation cell nuclear antigen (PCNA) and the apoptotic cells in the ureteric smooth muscle were examined. Hydroureter and fibrosis of the muscle layer became progressively aggravated during the period of obstruction in the ligated ureters of both groups. The severity of the hydroureter and fibrosis of muscle layer in the ligated ureters of the treated group was significantly milder than those of the control group. Expressions of COX-2 and PGE(2) were found in the smooth muscle layer of ligated ureters in the control group from day 14 after ureteric ligation, reached a peak on day 21, and then declined. Treatment with Celecoxib completely abolished the expression of COX-2 and PGE(2). The Celecoxib administration also decreased the expression of TGFbeta(1), alpha-SMA and the labeling index of apoptotic cells in the smooth muscle layer of ligated ureters in the treated group. In the contrast, treatment with Celecoxib significantly increased the expression of PCNA in the smooth muscle layer of ligated ureters in the treated group. We concluded that COX-2 inhibitor might ameliorate the damage of obstructed ureters, at least partly, via the inhibition of COX-2 and TGFbeta(1) expression.

Topics: Actins; Animals; Apoptosis; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Dinoprostone; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Hydronephrosis; Immunohistochemistry; Ligation; Muscle, Smooth; Organ Size; Proliferating Cell Nuclear Antigen; Rats; Rats, Sprague-Dawley; Time Factors; Transforming Growth Factor beta; Ureter; Ureteral Obstruction; Urethral Diseases

Non-invasive prognosis of the clinical progression of disease is of high interest, especially in newborn and children. Neonatal ureteropelvic (UPJ) junction obstruction needs close and invasive surveillance to determine the necessity of pyeloplasty. A number of groups have initiated research with the aim to find non-invasive biomarkers for UPJ obstruction. Two different strategies have been followed. One strategy, based on the knowledge obtained in animal models of UPJ obstruction, has identified a number of individual urinary markers of severe UPJ obstruction. Combining these markers might allow prediction of which patients will require surgery and in which patients UPJ obstruction will spontaneously resolve. The other strategy is based on urinary proteomics. In this strategy the entire urinary proteome is probed for a set of biomarkers that correlates with the degree of UPJ obstruction. In subsequent steps, these sets of urinary biomarkers are used for prediction of the clinical evolution of UPJ obstruction patients. This proteomic-based strategy allowed prediction, several months in advance, of the clinical evolution of neonates with UPJ-obstruction. Both strategies will be complementary and will hopefully replace in the near future the invasive follow-up of newborns with UPJ obstruction.

Topics: Animals; Biomarkers; Case-Control Studies; Collagen Type IX; Collagen Type V; Disease Models, Animal; Female; Humans; Hydronephrosis; Infant, Newborn; Kidney Pelvis; Mice; Pregnancy; Prospective Studies; Proteomics; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Transforming Growth Factor beta; Ureteral Obstruction; Urogenital Abnormalities

To study the potential role of pelviureteral junction obstruction (PUJO) in causing progressive renal damage in children through the renal expression of epidermal growth factor (EGF) and transforming growth factor-beta1 (TGF-beta1).. The expression of EGF and TGF-beta1 was evaluated in the renal tissues of 25 children with congenital hydronephrosis by immunohistochemistry, in situ hybridization, and reverse transcriptase polymerase chain reaction techniques.. Children with PUJO had a significant increase in TGF-beta1 and a marked reduction in EGF expression compared with controls. The TGF-beta1/glyceraldehyde phosphate dehydrogenase ratio in the hydronephrotic kidney and normal kidney was 0.53 +/- 0.13 and 0.24 +/- 0.10 respectively, and the difference was significant (P = 0.000). The EGF/glyceraldehyde phosphate dehydrogenase ratio in the hydronephrotic kidney and normal kidney was 0.15 +/- 0.06 and 0.55 +/- 0.13, respectively, and the difference was also significant (P = 0.0001). Positive correlations were found between the TGF-beta1 gene and the drainage clearance half-time (r = 0.47; P = 0.018), TGF-beta1 protein and drainage clearance half-time (r = 0.44; P = 0.028), TGF-beta1 gene and histologic grade (r = 0.53; P = 0.006), and TGF-beta1 protein and histologic grade (r = 0.76; P = 0.000). Negative correlations were found between the EGF gene and drainage clearance half-time (r = -0.59; P = 0.002), EGF protein and drainage clearance half-time (r = -0.61; P = 0.001), EGF gene and histologic grade (r = -0.58; P = 0.003), and EGF protein and histologic grade (r = -0.47; P = 0.019).. TGF-beta1 expression was increased and EGF expression was decreased in the renal tissue after clinical PUJO. The alterations of TGF-beta1 and EGF may play a potential role in the pathogenesis of renal damage in PUJO.

Topics: Child, Preschool; Epidermal Growth Factor; Female; Humans; Hydronephrosis; Kidney; Kidney Pelvis; Male; Transforming Growth Factor beta; Transforming Growth Factor beta1; Ureteral Obstruction

Tissue inhibitor of metalloproteinase-3 (Timp-3), an inhibitor of matrix-degrading enzymes, is an important molecule for maintenance of the extracellular matrix. In this study, we generated Timp-3-deficient mice and used them to examine the effect of Timp-3-deficiency on blood pressure and to investigate the role of Timp-3 in the kidney following unilateral ureteral obstruction. The blood pressure and heart rate of Timp-3-deficient mice were not significantly different from those of wild-type mice. On the other hand, the obstructed kidneys of Timp-3-deficient mice developed more severe hydronephrosis than those of wild-type animals. Matrix metalloproteinase activities assessed by in situ zymography and transforming growth factor-beta expression were elevated in Timp-3-deficient mice. The renal tissues were thinner and the ratio of renal medulla to cortex was significantly lower in the obstructed Timp-3-deficient kidneys. These findings indicate that Timp-3-deficiency does not substantially affect the blood pressure in mice, and that Timp-3 plays an important role in the maintenance of renal macrostructure after unilateral ureteral obstruction.

Topics: Animals; Blood Pressure; Extracellular Matrix; Heart Rate; Hydronephrosis; Kidney Cortex; Kidney Medulla; Mice; Mice, Inbred C57BL; Mice, Knockout; Tissue Inhibitor of Metalloproteinase-3; Transforming Growth Factor beta; Ureteral Obstruction

The aim of this study was to test the hypothesis that expression of epidermal growth factor (EGF) and transforming growth factor-beta 1 (TGF-beta 1) may be altered in stenotic tissue of patients with congenital hydronephrosis caused by pelviureteric junction (PUJ) obstruction and to evaluate the role of these 2 growth factors.. The expression of EGF and TGF-beta 1 was evaluated in tissue specimens in 25 children with PUJ obstruction and 15 controls with normal PUJs by immunohistochemistry, in situ hybridization, and reverse transcriptase polymerase chain reaction (RT-PCR) techniques. All the signals of mRNA products were normalized to the mRNA levels of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) a housekeeping gene, as a ratio.. On RT-PCR study, the amount of TGF-beta 1 mRNA in stenotic tissue was higher than in controls, in addition, EGF gene expression in the obstructed junction was significantly lower than in normal junctions. The TGF-beta 1 to GAPDH ratio was 0.57 +/- 0.26 and 0.36 +/- 0.19 in the stenotic tissue and the normal ureter, respectively (P =.012). The EGF to GAPDH ratio was 0.17 +/- 0.08 and 0.37 +/- 0.14 in the stenotic tissue and the normal ureter, respectively (P =.0001). Furthermore, the positive correlations were found between TGF-beta1 gene and protein expression (r = 0.601; P =.001), TGF-beta 1 gene and drainage clearance half-time (T1/2) (r = 0.474; P =.017), TGF-beta 1 protein expression, and T1/2 (r = 0.516; P =.008). A negative correlation was found between EGF gene and T1/2 (r = -0.448; P =.025). On immunolabeling and in situ hybridization labeling, the expression of TGF-beta 1 protein was strongly positive and confined to the muscle cells, spindle cells, and collagen fibers in the stenotic tissue; the expression of TGF-beta 1 mRNA was moderately positive and mainly distributed in the collagen of the stenotic segment, both the expression of EGF protein and mRNA were negative in the normal ureter.. There were increased TGF-beta 1 mRNA expression and decreased EGF mRNA expression in the stenotic tissue after clinical ureteropelvic junction obstruction. The alteration of EGF and TGF-beta 1 expression may be involved in the pathogenesis of congenital hydronephrosis.

Topics: Child; Child, Preschool; Constriction, Pathologic; Epidermal Growth Factor; Female; Gene Expression Regulation; Genetics; Humans; Hydronephrosis; In Situ Hybridization; Kidney; Kidney Pelvis; Male; Radionuclide Imaging; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1; Ureter; Ureteral Obstruction

Most of our knowledge concerning renal obstruction has been derived from experimental animal models, and it is not yet well defined in spontaneous hydronephrosis. The aim of our study is to evaluate the roles of transforming growth factor-beta1 (TGF-beta1) and apoptosis in congenital hydronephrotic kidneys in comparison with experimental models.. We made histological studies on kidneys from 6-week-old Wistar-Imamichi rats with congenital unilateral hydronephrosis as well as surgical models of complete or partial unilateral ureteral obstruction. The severity of hydronephrotic kidneys was evaluated on routine hematoxylin and eosin (H&E) stained sections, and the tubulointerstitial fibrosis analyzed morphometrically on Masson's trichrome stained sections. Renal tubular atrophy was assessed on periodic acid Schiff (PAS) stained sections, and tubular cell apoptosis assessed with TUNEL technique. The renal TGF-beta1 level was determined by a sandwich enzyme-linked immunosorbent assay (ELISA).. We observed a significant loss of kidney weight with profound compensatory growth of the contralateral kidney in rats with congenital hydronephrosis. Most of the hydronephrotic kidneys were markedly enlarged with dilatation of the collecting system, renal parenchymal thinning, tubular atrophy, interstitial infiltration and fibrosis. The renal TGF-beta1 level was markedly elevated in hydronephrotic kidneys as compared with normal controls (326.01 +/- 30.64 pg/mg protein vs 227.81 +/- 11.07 pg/mg protein, P < 0.01). The tubular apoptotic score in hydronephrotic kidneys was also significantly higher than normal controls (2.17 +/- 0.50/HPF [high power field]vs 0.14 +/- 0.04/HPF, P < 0.01). The increased TGF-beta1 and apoptotic status paralleled the histological changes of tubulointerstitial fibrosis and tubular atrophy. Similar findings were also obtained in experimental obstructive models.. In comparison with surgical models of partial and complete ureteral obstruction, our data provide solid morphological and molecular evidences of renal obstruction in rats with congenital hydronephrosis.

Topics: Animals; Fibrosis; Hydronephrosis; Kidney Tubules; Male; Organ Size; Rats; Rats, Wistar; Transforming Growth Factor beta; Transforming Growth Factor beta1

Alterations caused by renal obstruction in developing kidneys are of particular interest in basic research of congenital obstructive uropathy. In rats nephrogenesis mainly occurs 7 to 10 days postnatally. Therefore, surgically induced neonatal ureteral obstruction in rats has been suggested to be analogous to congenital obstruction in the fetus. An attempt less prone to surgical artifacts and assessing even earlier developmental stages is to monitor the development of obstructed kidneys in rats with congenital obstructive uropathy.. Rats from an inbred strain with congenital renal obstruction in 70% of their littermates were observed. Morphologically, significant hydronephrosis was not detected before day 5 post partum and progressed with age. Unilateral obstructed kidneys were compared with contralateral kidneys and kidneys from healthy control animals at ages of 1, 5, 10, 18 and 32 days. A total of 72 renal units were investigated. The renal messenger RNA expression of renin and transforming growth factor-beta1 (TGF-beta1) was quantified by competitive quantitative reverse transcription polymerase chain reaction using a gene specific complementary RNA standard.. In controls the gene expression of renin decreased from day 1 to day 18 and remained stable. TGF-beta1 expression increased during the first 10 days and then decreased again. Renin expression of the obstructed kidneys was reduced (p <0.05) on day 1, increased to a maximum versus controls (p <0.01) on day 10 and decreased to an unchanged elevated level (p <0.01) on days 18 and 32. Renin expression of the contralateral kidneys showed no significant alterations to control kidneys. Messenger RNA expression of TGF-beta1 of obstructed kidneys stayed decreased during the first 10 days (p <0.05), then increased excessively on day 18 (p <0.01) and slightly decreased on day 32. TGF-beta1 expression of the contralateral kidneys was parallel to controls on a slightly elevated level, increased on day 18 and returned to control level on day 32.. Within the postpartum period of nephrogenesis gene expression of renin and TGF-beta1 was decreased in obstructed kidneys compared to controls. As the renin angiotensin system and TGF-beta1 have important functions in normal kidney development, these results suggest impaired nephrogenesis of congenital obstructed kidneys even before the onset of morphological signs of hydronephrosis. These features differ from surgical induced unilateral ureteral obstruction at birth and promise new insights into the pathophysiology of congenital obstructive uropathy.

Topics: Animals; Female; Gene Expression; Hydronephrosis; Male; Rats; Rats, Inbred Strains; Renin; RNA, Messenger; Transforming Growth Factor beta

To investigate whether partial ureteral obstruction (PUO) in the fetus induces dysregulation of the renin-angiotensin system (RAS) and of transforming growth factor-beta 1 (TGF-beta1) and tissue inhibitors of metalloproteinase (TIMP1) expression. Previous studies have indicated that renal and urinary tract development depend on an intact renal RAS. Fetal urinary obstruction is distinct from postnatal obstruction. It has been suggested in postnatal animal studies that dysregulation of the RAS, and subsequent increased expression of TGF-beta1 and TIMP1, leads to changes in extracellular matrix composition.. Bilateral PUO was created in 4 fetal sheep. Seven animals (four obstructed and three controls) were killed at birth and their kidneys removed. Semiquantitative reverse transcriptase-polymerase chain reaction was used to quantify the levels of renin, angiotensinogen, angiotensin receptor type 1 (AT1 receptor), angiotensin receptor type 2 (AT2 receptor), TGF-beta1, and TIMP1. These messages were normalized to glyceraldehyde-3-phosphate dehydrogenase mRNA.. All obstructed animals had moderate to severe hydronephrosis with enlarged kidneys (mean weight 22.0 g versus 9.4 g for the control animals; P <0.05). The increase in the levels of renin, angiotensinogen, AT1 receptor, TGF-beta1, and TIMP1 mRNA was significant in the PUO group compared with the control group (P <0.05). AT2 receptor levels did not increase, but the AT1/AT2 mRNA ratio was significantly increased over normal (P <0.005). Also, a significant linear correlation was found between the increased renal weight and increased TGF-beta1 mRNA levels (P <0.005).. Our findings suggest that fetal PUO can cause upregulation of the renal RAS and increased expression of TGF-beta1 and TIMP1, which may alter the balance between the generation and degradation of the extracellular matrix. The coordinate increases in renin, angiotensinogen, and AT1 receptor mRNA levels in chronic fetal PUO may represent a maladaptive response that contributes to interstitial fibrosis and prolonged vasoconstriction. RAS components and growth factors, particularly TGF-beta1, may be considered relevant targets in the prevention and treatment of congenital obstructive nephropathy.

Topics: Angiotensinogen; Animals; Extracellular Matrix; Fetal Diseases; Hydronephrosis; Kidney; Organ Size; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Receptors, Angiotensin; Renin; Renin-Angiotensin System; Sheep; Tissue Inhibitor of Metalloproteinase-1; Transforming Growth Factor beta; Transforming Growth Factor beta1; Up-Regulation; Ureteral Obstruction

To assess apoptosis in congenital hydronephrosis and discuss its clinical significance.. Apoptosis was detected in 15 kidneys from children with congenital hydronephrosis (5 mild hydronephrosis, 5 moderate hydronephrosis and 5 severe hydronephrosis) using the electronmicroscope, in situ gap labeling of fragmented nuclear DNA and DNA fragmentation analysis.. Apoptosis was seen in kidneys from children with congenital hydronephrosis. Margination of nuclear chromatin was identified and rounded apoptotic bodies were seen. The mean apoptotic index was 0.0941 +/- 0.017 in severe hydronephrosis, 0.0325 +/- 0.0169 in moderate hydronephrosis, and 0.0021 +/- 0.0031 in mild hydronephrosis. There was a significant difference between severe and moderate hydronephrosis (P = 0.0005), as well as between moderate and mild hydronephrosis (P = 0.0154). Moreover, with an increasing degree of hydronephrosis, the number of apoptotic cells also increased. Five kidneys with severe hydronephrosis and one kidney with moderate hydronephrosis showed typical apoptotic bands.. Apoptosis might participate in damaging kidneys in children with congenital hydronephrosis.

Topics: Apoptosis; Child; Child, Preschool; DNA Fragmentation; Epidermal Growth Factor; Female; Humans; Hydronephrosis; Infant; Kidney Tubules; Male; Transforming Growth Factor beta

Partial obstruction of the upper urinary tract, a frequent challenge for the pediatric urologist, leads to renal damage, if deobstruction is delayed. Several but sometimes unsatisfactory animal models have been developed to study this phenomenon. Obstruction created by surgical manipulation lacks adequate correlation with a developing congenital obstruction. In some animals with congenital hydronephrosis, evidence of renal obstruction is absent. A study of the renal morphology of rats with hereditary unilateral hydronephrosis has exhibited clear evidence of renal obstruction distinguishable from renal dilatation. The renal mRNA expression of renin and transforming-growth factor-beta1 (TGF-beta1) was measured by a semiquantitative RT-PCR technique. In hydronephrotic kidneys, a marked loss of parenchyma, atrophy and dilation of tubuli and collecting ducts and interstitial fibrosis was observed. The mRNA expression of renin was increased significantly in comparison to controls, whereas the contralateral kidneys showed renin activity below control levels. TGF-beta1 expression was markedly increased in hydronephrotic kidneys, whereas contralateral kidneys did not differ significantly from control values. These data suggest the presence of renal obstruction and not only renal dilatation in these rats with congenital hydronephrosis. This colony seems to be a representative animal model to study congenital renal obstruction even in the fetal period without the need of surgical manipulation.

Topics: Actins; Animals; DNA Primers; Fibrosis; Gene Expression; Hydronephrosis; Kidney; Rats; Renin-Angiotensin System; RNA, Messenger; Transforming Growth Factor beta; Ureteral Obstruction

Increased expression of TGF-beta1 but not of its receptors contributes to human obstructive nephropathy.. Previous studies have revealed an increased expression of transforming growth factor-beta1 (TGF-beta1) and deposition of extracellular matrix in the kidney of animals with ureteral obstruction. However, these relationships have not been elucidated in the hydronephrotic kidney of humans.. We analyzed the tissue expression of extracellular matrix proteins, TGF-beta1, and its receptors in the human kidney with ureteral obstruction by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR). Obstructed kidneys (OBKs) were obtained from patients with ureteral tumors. A kidney specimen from patients with a renal tumor was used as control (CNKs).. The interstitial volume was significantly increased in OBKs in comparison with CNKs. OBKs showed increased deposition of collagen types I and IV and fibronectin in the renal interstitium. RT-PCR revealed overexpression of collagen alpha1(IV) mRNA and fibronectin mRNA in OBKs. OBKs showed a significantly increased mRNA expression of TGF-beta1 in comparison with CNKs. The immunoreactivity for TGF-beta1 increased markedly in the interstitium of OBKs. There was a significant correlation between the TGF-beta1 mRNA level and the interstitial volume. However, there was no significant difference between OBKs and CNKs in the relative mRNA level nor in immunoreactivity for TGF-beta receptors.. These data suggest that TGF-beta1 may contribute to the interstitial fibrosis found in the human kidney with ureteral obstruction, mainly because of an increase in the expression of this cytokine without significant changes to its receptors.

Topics: Activin Receptors, Type I; Adult; Aged; Antisense Elements (Genetics); Collagen; Extracellular Matrix Proteins; Female; Fibronectins; Fibrosis; Gene Expression; Humans; Hydronephrosis; Kidney Cortex; Male; Middle Aged; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type I; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; RNA, Messenger; Transforming Growth Factor beta; Ureteral Obstruction

Transforming growth factor (TGF)-beta1 is a potential mediator of tubulointerstitial (TI) fibrosis in the rat unilateral ureteral obstruction (UUO) model. Decorin is a protein composed of a core protein and a chondroitin sulfate side chain and is capable of inactivating TGF-beta. Since TGF-beta strongly induces the synthesis of decorin in experimental glomerulonephritis, it was our intent to investigate whether altered decorin expression is operant in the rat UUO model. Renal cortical decorin mRNA levels initially became elevated (2.5-fold) in obstructed kidney (OBK) versus contralateral unobstructed kidney (CUK) 24 hours post-UUO and remained greater in the OBK specimens at 48 (2.3-fold), 96 (2.2-fold), and 168 (1.9-fold) hours post-ureteral ligation. Whole-body X-irradiation 11 days prior to UUO significantly reduced decorin mRNA at 24 and 96 hours post-UUO. On immunolabeling, decorin was only evident in the adventitia of blood vessels in CUK specimens at any time point after UUO. In contrast, OBK specimens initially demonstrated periglomerular and peritubular interstitial localization of decorin at 96 hours post-ureteral ligation, which became even more intense and diffuse in the tubulointerstitium at 168 hours post-UUO. On Western analysis, there were highly significant increases in decorin protein expression in the OBK versus the CUK specimens at 96 and 168 hours post-UUO. Levels of active TGF-beta1 in the renal cortex of OBK were 1.9- and 3.6-fold higher than CUK at 48 and 96 hours post-UUO. In summary, we demonstrated that post-UUO, decorin mRNA and protein expression is up-regulated in the renal cortex of OBK, but not CUK, specimens in a temporal parallel with active TGF-beta1 levels and macrophage infiltration. We postulate that the development of TI fibrosis in this model may be related to only a physiologic induction of decorin by TGF-beta, and that pharmacologic levels may be required to retard or prevent scarring via TGF-beta inhibition.

Topics: Animals; Culture Media, Conditioned; Decorin; Disease Models, Animal; Extracellular Matrix Proteins; Fibrosis; Hydronephrosis; Immunohistochemistry; In Vitro Techniques; Kidney Cortex; Kidney Diseases; Male; Proteoglycans; Rats; Rats, Sprague-Dawley; RNA, Messenger; Transforming Growth Factor beta; Up-Regulation; Ureteral Obstruction; Whole-Body Irradiation

To gain insight into the role of transforming growth factor-beta 1 (TGF-beta 1) in the development of kidney pathology following fetal obstruction, we measured TGF-beta 1 gene expression, the active peptide, and the urinary concentration in a model of fetal bilateral urinary obstruction (BUO) in sheep. Fetal lambs underwent BUO at 60 (FO-60) or 80 days (FO-80) of gestation and were studied at 120 days. Independently of the onset or duration of obstruction, all fetuses developed type IV dysplasia (IV) associated with an arrest in the nephrogenesis or hydronephrosis. Fetal glomerular filtration rate was not significantly modified, whereas sodium tubular reabsorption was significantly decreased, and urinary TGF-beta 1 concentration was elevated in hydronephrosis but not in IV. Levels of TGF-beta 1 mRNA were increased in hydronephrosis compared with normal kidneys, and active TGF-beta 1 immunoreactivity was increased in both hydronephrotic and IV kidneys. In summary, TGF-beta 1 may play a role in the development of hydronephrosis and dysplasia in kidneys following fetal BUO. Its role in the arrest of nephrogenesis observed in the IV kidneys remains to be proved.

Topics: Animals; Female; Gene Expression Regulation, Developmental; Gestational Age; Hydronephrosis; Kidney; Kidney Glomerulus; Pregnancy; Sheep; Transforming Growth Factor beta; Urethral Obstruction

To determine if there are measurable quantities of transforming growth factor-beta 1 (TGF-beta 1) in the urine of children with either normal or pathologic conditions of the urinary tract, specifically vesicoureteral reflux (VUR) and ureteropelvic junction obstruction (UPJO). We also sought to determine if the urine TGF-beta level could distinguish between renal obstruction and no obstruction.. Preoperative bladder urine from consecutive patients undergoing pyeloplasty (UPJO group; n = 13), ureteral reimplantation (VUR group; n = 11), or circumcision/orchiopexy (control group; n = 19) as well as urine from the renal pelvis of the UPJO group was collected. The urine level of TGF-beta 1 was measured using a quantitative sandwich enzyme immunoassay technique.. Urine level of TGF-beta 1 was detected in each group: control (26.6 +/- 6.3 pg/mL), reflux (22.1 +/- 9.6), UPJO-pelvic urine (82.4 +/- 19.3), UPJO-bladder urine (31.2 +/- 8.2). The urine TGF-beta 1 concentration in pelvic urine in the UPJO group was significantly higher than that in bladder urine in children in the UPJO group (p = 0.03). TGF-beta 1 concentrations were similar from the bladder of children in all three study groups (p = NS).. Urine TGF-beta 1 is detectable in children with normal and pathologic urinary tracts. The level of this urine marker is elevated in the renal pelvis of children with UPJO compared to the level in the bladder of either obstructed or nonobstructed upper urinary tracts.

Topics: Biomarkers; Child; Child, Preschool; Female; Humans; Hydronephrosis; Infant; Kidney Pelvis; Male; Transforming Growth Factor beta; Ureteral Obstruction; Vesico-Ureteral Reflux

Interstitial fibrosis is a common outcome of longterm ureteral obstruction. One pathological arm of the fibrotic reaction in diverse tissue loci and experimental models is the retraction of granulation tissue. The role of the myofibroblast in granulation tissue contraction and fibrocontractive diseases has been well established, but the mechanisms leading to differentiation of fibroblastic cells into myofibroblasts during the evolution of inflammation are not yet fully clarified. Investigators using other model systems have shown that macrophage-derived transforming growth factor-beta 1 (TGF-beta 1) may be pivotal in the process of myofibroblast modulation. Our laboratory has shown that the unilateral ureteral obstruction in the rat is characterized by a 20-fold increment in infiltrating renal cortical interstitial macrophages, an increase in cortical TGF-beta 1 gene expression, which parallels the infiltrating macrophage burden, and immunolocalization of this peptide growth factor in close proximity to resident interstitial fibroblasts. Because of this model's features, it was our aim to assess whether a myofibroblastic modulation was operant in the renal cortex of obstructed rat kidneys versus the control contralateral unobstructed kidney specimens. Immunolabeling for alpha-smooth muscle actin and the intermediate filament protein, desmin, was detected and steadily intensified from 24 to 96 hours after unilateral ureteral obstruction in obstructed kidneys only. In temporal concert with the detection of alpha-smooth muscle actin protein, the mRNA expression for this cytoskeletal component exhibited 3.7-, 15.7-, and 4.1-fold increments in the renal cortex of obstructed kidneys versus the contralateral unobstructed kidney specimens at 24, 48, and 96 hours after unilateral ureteral obstruction, respectively. Whole body X-irradiation, administered to rats 11 days before proximal left ureteral ligation, significantly lowered cortical interstitial macrophage number, cortical TGF-beta and alpha-smooth muscle actin mRNA levels as well as the intensity of immunolabeling for alpha-smooth muscle actin from 12 to 96 hours after unilateral ureteral obstruction. These data support a postulate that renal cortical TGF-beta 1, derived from the infiltrating macrophage, in part, contributes to the subsequent interstitial fibrosis response to renal injury by fostering the modulation of fibroblasts to myofibroblasts within the renal cortex after ureteral obstruction.

Topics: Actins; Animals; Base Sequence; Blotting, Northern; Cell Differentiation; Desmin; Fibroblasts; Hydronephrosis; Immunoenzyme Techniques; Kidney; Male; Molecular Sequence Data; Muscle, Smooth; Rats; Rats, Sprague-Dawley; RNA, Messenger; Transforming Growth Factor beta; Whole-Body Irradiation

Early cellular and molecular derangements have been evaluated as potential pivotal factors for the late development of interstitial fibrosis after experimental hydronephrosis. In this study, we delineated the kinetics of renal cortical macrophage infiltration as well as the cortical expression of transforming growth factor-beta 1 (TGF-beta 1) and monocyte chemoattractant peptide-1 (MCP-1) at 12, 48, and 96 h after unilateral ureteral obstruction (UUO). Interstitial macrophage number in the obstructed kidney versus the contralateral unobstructed kidney (CUK) significantly increased by 12 (11.1 +/- 0.9 vs. 4.5 +/- 0.6), 48 (27.5 +/- 0.9 vs. 4.0 +/- 0.8), and 96 h (71.4 +/- 4.6 vs. 3.2 +/- 0.4) after UUO. MCP-1 mRNA was detected from 12 to 96 h in the obstructed kidney but was absent in the CUK specimens at all time points. Apical tubular MCP-1 expression, on immunolabeling, was present from 12 through 96 h after UUO in the obstructed kidney but not the CUK specimen. On Northern analysis, there were highly significant 2.6-, 5.8-, and 7.0-fold increments in renal cortical TGF-beta 1 mRNA levels at 12, 48, and 96 h, respectively, in the obstructed kidney versus the CUK specimen. Intracellular TGF-beta 1, on immunolabeling, was detected only in the obstructed kidneys of UUO rats at all three time points and was confined to peritubular cells of the renal interstitium. A significant (P < 0.005) correlation (r = 0.95) between interstitial macrophage number and cortical TGF-beta 1 mRNA levels was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Blotting, Northern; Cell Movement; Chemokine CCL2; Chemotactic Factors; Cytokines; Hydronephrosis; Immunohistochemistry; Kidney Cortex; Kidney Tubules; Macrophages; Male; Rats; Rats, Sprague-Dawley; Staining and Labeling; Transforming Growth Factor beta; Ureteral Obstruction

Partial ureteral obstruction in the weanling rat leads to hydronephrosis of the ipsilateral kidney and renal cell deletion through the process of programmed cell death known as apoptosis. The apoptotic response following partial ureteral obstruction in weanling Sprague-Dawley rats was studied using the traditional markers of apoptosis, including deoxyribonucleic acid (DNA) laddering pattern on agarose gel electrophoresis, in situ gap labeling of fragmented DNA for quantitative apoptotic body determination, polyadenylated messenger ribonucleic acid (mRNA) expression of sulfated glycoprotein-2, and polyadenylated mRNA expression of epidermal growth factor and transforming growth factor-beta. Partial ureteral obstruction resulted in a progressive increase in the intensity of DNA fragmentation associated with apoptosis during the initial 3 weeks. Quantitative apoptotic body counting revealed a 3-fold increase by week 3 of partial obstruction. This increase represented a level of apoptosis, which is 65% of that observed in complete ureteral obstruction. By week 2 of partial obstruction there was a 13-fold increase in the expression of sulfated glycoprotein-2 mRNA, as well as changes in the growth factor environment characterized by a decline in the constitutive expression of epidermal growth factor mRNA and an increase in the expression of transforming growth factor-beta mRNA. These altered levels represent changes in expression comparable to those observed during the apoptotic response following complete ureteral obstruction, although the time course is delayed by 2 to 3 weeks.

Topics: Animals; Apoptosis; Blotting, Northern; Clusterin; DNA; Electrophoresis, Agar Gel; Epidermal Growth Factor; Glycoproteins; Hydronephrosis; Kidney Tubules; Molecular Chaperones; Rats; Rats, Sprague-Dawley; RNA, Messenger; Transforming Growth Factor beta; Ureteral Obstruction

Unilateral ureteral obstruction in the rat leads to hydronephrosis of the affected kidney and renal cell deletion through the process of apoptosis. We studied this experimental model to determine whether acute alterations in renal growth factor expression might be involved in the initiation of the apoptotic response. Northern blot analysis of hydronephrotic, contralateral and sham operated kidney polyadenylated messenger ribonucleic acid (mRNA) was performed to quantitate the expression of mRNA encoding the growth factors epidermal growth factor, transforming growth factor-beta and insulin-like growth factor II during the first 48 hours following ureteral obstruction. Although the expression of the insulin-like growth factor II mRNA was unchanged by ureteral obstruction, the expression of epidermal growth factor mRNA rapidly declined in the obstructed kidney during this period. The loss of epidermal growth factor expression was further confirmed by an immunocytochemical staining procedure that demonstrated high concentrations of epidermal growth factor in control renal tubules and a drastic loss of this staining in obstructed renal tubules. In contrast, expression of transforming growth factor-beta mRNA increased in the obstructed kidney. We believe that the altered growth factor environment of the hydronephrotic kidney might be an initiating factor in the onset of renal apoptosis associated with this condition.

Topics: Animals; Blotting, Northern; Epidermal Growth Factor; Growth Substances; Hydronephrosis; Immunohistochemistry; Insulin-Like Growth Factor II; Kidney; Rats; Rats, Inbred Strains; RNA, Messenger; Transforming Growth Factor beta; Ureteral Obstruction