MicroRNA-302b mitigates renal fibrosis via inhibiting TGF-ß/Smad pathway activation

Renal fibrosis is one of the most significant pathological changes after ureteral obstruction. Transforming growth factor-β (TGF-β) signaling pathway plays essential roles in kidney fibrosis regulation. The aims of the present study were to investigate effects of microRNA-302b (miR-302b) on renal fibrosis, and interaction between miR-302b and TGF-β signaling pathway in murine unilateral ureteral obstruction (UUO) model. Microarray dataset GSE42716 was downloaded by retrieving Gene Expression Omnibus database. In accordance with bioinformatics analysis results, miR-302b was significantly down-regulated in UUO mouse kidney tissue and TGF-β1-treated HK-2 cells. Masson's trichrome staining showed that miR-302b mimics decreased renal fibrosis induced by UUO. The increased mRNA expression of collagen I and α-smooth muscle actin (α-SMA) and decreased expression of E-cadherin were reversed by miR-302b mimics. In addition, miR-302b up-regulation also inhibited TGF-β1-induced epithelial mesenchymal transition (EMT) of HK-2 cells by restoring E-cadherin expression and decreasing α-SMA expression. miR-302b mimics suppressed both luciferase activity and protein expression of TGF-βR2. However, miR-302b inhibitor increased TGF-βR2 luciferase activity and protein expression. Meanwhile, miR-302b mimics inhibited TGF-βR2 mRNA expression and decreased Smad2 and Smad3 phosphorylation in vivo and in vitro. Furthermore, over-expression of TGF-βR2 restored the miR-302b-induced decrease of collagen I and α-SMA expression. In conclusion, this study demonstrated that miR-302b attenuated renal fibrosis by targeting TGF-βR2 to suppress TGF-β/Smad signaling activation. Our findings showed that elevating renal miR-302b levels may be a novel therapeutic strategy for preventing renal fibrosis.

Ureteropelvic junction obstruction caused by metastatic cholangiocarcinoma

ABSTRACT We describe the rare case of a 61-year-old female with right ureteropelvic junction (UPJ) obstruction caused by metastatic cholangiocarcinoma. Her past medical history was notable for cholangiocarcinoma treated with neoadjuvant chemoradiation and two orthotopic liver transplants six years earlier. Urology was consulted when she presented with flank pain and urinary tract infection. Diagnostic workup demonstrated right UPJ obstruction. She was managed acutely with percutaneous nephrostomy. She subsequently underwent robotic pyeloplasty and intrinsic obstruction of the UPJ was discovered. Histological examination revealed adenocarcinoma, consistent with systemic recurrence of the patient's known cholangiocarcinoma.

Positive outcomes of phosphodiesterase type 5 inhibitor on histopathologic and biochemical changes induced by ureteral obstruction

SUMMARY OBJECTIVES: We examined the effects of tadalafil, one of the phosphodiesterase type 5 (PDE5) inhibitors, in a rat model of with partial and complete unilateral ureteral obstruction (UUO). METHODS: The rats were divided into 5 groups: sham (n=6), partial unilateral ureteral obstruction (PUUO, n=6), PUUO with tadalafil treatment (PUUO+T; Cialis, 10 mg/72 h, intragastric; Lilly, Indianapolis, Indiana, USA), complete unilateral ureteral obstruction (CUUO, n=6), and CUUO with tadalafil treatment (CUUO+T). RESULTS: Fifteen days after the UUO, the ureter presented changes in the layers of urothelium and significant infiltration of inflammatory cells in the PUUO and CUUO groups. Compared with the sham, PUUO and CUUO groups had severe increased inflammatory cell infiltration. The urothelial epithelium exhibited cell degeneration and loss because of the swollen, atrophic, and denuded epithelial cells in the PUUO and CUUO groups. In the PUUO+T and CUUO+T groups, the urothelium revealed less epithelial cell degeneration and loss. The expressions of α-smooth muscle actin (α-SMA) and transforming growth factor-β (TGF-β) exhibited up-regulation in the PUUO and CUUO groups. The expression of TGF-β decreased positively correlated with that of α-SMA in the tadalafil therapy groups, PUUO+T and CUUO+T. CONCLUSION: The phosphodiesterase type 5 inhibitor's tadalafil reduced expressions of α-SMA and TGF-β in the obstructed ureters, measured by biochemical examinations. In addition, tadalafil decreased urothelium degeneration due to the decreased epithelial cell loss and inflammatory cell infiltration. Our results show that tadalafil prevents or slows down the onset of ureter inflammation and urothelial degeneration in rats with UUO.

RESUMO OBJETIVOS: Examinamos os efeitos do tadalafil em um dos inibidores da fosfodiesterase tipo 5 (PDE5) em um modelo de rato com obstrução ureteral unilateral parcial e completa (UUO). MÉTODOS: Os ratos foram divididos em cinco grupos: sham (n = 6), obstrução ureteral unilateral parcial (PUUO, n = 6), PUUO com tadalafil (PUUO T; Cialis, 10 mg/72 h, intragástrica; Lilly, Indianapolis, Indiana, EUA), completa obstrução ureteral unilateral (CUUO, n = 6) e CUUO com tratamento com tadalafil (CUUO T). RESULTADOS: Quinze dias após a UUO, o ureter apresentou alterações nas camadas de urotélio e infiltração significativa de células inflamatórias nos grupos PUUO e CUUO. Em comparação com os grupos sham, PUUO e CUUO, houve um aumento grave da infiltração de células inflamatórias. O epitélio urotelial exibiu degeneração e perda celular devido às células epiteliais inchadas, atróficas e desnudas nos grupos PUUO e CUUO. Nos grupos PUUO T e CUUO T, o urotélio revelou menor degeneração e perda de células epiteliais. Nós mostramos que a expressão da actina do músculo liso-α (α-SMA) e do fator de crescimento transformador-β (TGF-β) foram exibidas como sub-regulação nos grupos PUUO e CUUO. A expressão do TGF-β foi diminuída positivamente correlacionada com a da α-SMA nos grupos de terapia com tadalafil, PUUO T e CUUO T. CONCLUSÃO: O tadalafil do inibidor da fosfodiesterase tipo 5 reduziu as expressões α-SMA e TGF-β nos ureteres obstruídos, medidos por exames bioquímicos. Além disso, o tadalafil diminuiu a degeneração do urotélio devido à diminuição da perda de células epiteliais e da infiltração de células inflamatórias. Nossos resultados mostram que o tadalafil previne ou retarda o início da inflamação do ureter e degeneração urotelial em ratos com UUO.

Fluorofenidone inhibits apoptosis of renal tubular epithelial cells in rats with renal interstitial fibrosis

This study aimed to investigate the mechanism of fluorofenidone (AKF-PD) in treating renal interstitial fibrosis in rats with unilateral urinary obstruction (UUO). Thirty-two male Sprague-Dawley rats were randomly divided into sham, UUO, UUO + enalapril, and UUO + AKF-PD groups. All rats, except sham, underwent left urethral obstruction surgery to establish the animal model. Rats were sacrificed 14 days after surgery, and serum was collected for renal function examination. Kidneys were collected to observe pathological changes. Immunohistochemistry was performed to assess collagen I (Col I) protein expression, and terminal deoxynucleotidyl transferase-mediated nick end-labeling staining to observe the apoptosis of renal tubular epithelial cells. The expression of Fas-associated death domain (FADD), apoptotic protease activating factor-1 (Apaf-1), and C/EBP homologous protein (CHOP) proteins was evaluated by immunohistochemistry and western blot analysis. AKF-PD showed no significant effect on renal function in UUO rats. The pathological changes were alleviated significantly after enalapril or AKF-PD treatment, but with no significant differences between the two groups. Col I protein was overexpressed in the UUO group, which was inhibited by both enalapril and AKF-PD. The number of apoptotic renal tubular epithelial cells was much higher in the UUO group, and AKF-PD significantly inhibited epithelial cells apoptosis. The expression of FADD, Apaf-1, and CHOP proteins was significantly upregulated in the UUO group and downregulated by enalapril and AKF-PD. In conclusion, AKF-PD improved renal interstitial fibrosis by inhibiting apoptosis of renal tubular epithelial cells in rats with UUO.

Rhein alleviates renal interstitial fibrosis by inhibiting tubular cell apoptosis in rats

BACKGROUND: Ureteral obstruction causes injury of the renal tissues and can irreversibly progress to renal fibrosis, with atrophy and apoptosis of tubular cells. The goal of the current study was to examine the effects of rhein on the apoptosis o renal tubular cells as well as renal fibrosis using a rodent model of unilateral ureteral obstruction (UUO). METHODS: UUO was induced through ureteral ligation, then animals received treatments with rhein or vehicle. The control rats only received sham operation. The renal tissue was harvested 1 week after surgery for assessment of kidney fibrosis. RESULTS: The expressions of collagen I and α-smooth muscle actin (α-SMA), as well as the severity of renal tubular apoptosis and fibrosis were time-dependently increased following UUO. Treatments with rhein partially inhibited such responses. Renal interstitial fibrosis was associated with STAT3 (signal transducer and activator of transcription 3) phosphorylation as well as altered expressions of Bax and Bcl2, both apoptosis-related proteins. Treatment with rhein also partly blocked these responses. CONCLUSION: These findings demonstrated that rhein mitigated apoptosis of renal tubular cell as well as renal fibrosis in a UUO rodent model. This curative effect is likely mediated via suppression of STAT3 phosphorylation.

Beneficial effects of Oltipraz, nuclear factor - erythroid - 2 - related factor 2 (Nrf2), on renal damage in unilateral ureteral obstruction rat model

ABSTRACT Introduction: We investigated whether Oltipraz (OPZ) attenuated renal fibrosis in a unilateral ureteral obstruction (UUO) rat model. Materials and Methods: We randomly divided 32 rats into four groups, each consisting of eight animals as follows: Rats in group 1 underwent a sham operation and received no treatment. Rats in group 2 underwent a sham operation and received OPZ. Rats in group 3 underwent unilateral ureteral ligation and received no treatment. Group 4 rats were subjected to unilateral ureteral ligation plus OPZ administration. Transforming growth factor beta-1 (TGF-β1), E-cadherin, nitric oxide (NO) and hydroxyproline levels were measured. Histopathological and immunohistochemical examinations were carried out. Results: TGF-β1, NO and E-cadherin levels in the UUO group were significantly higher than the sham group and these values were significantly different in treated groups compared to the UUO group. In rats treated with UUO + OPZ, despite the presence of mild tubular degeneration and less severe tubular necrosis, glomeruli maintained a better morphology when compared to the UUO group. Expressions of α-SMA in immunohistochemistry showed that the staining positivity decreased in the tubules of the OPZ-treated group. Conclusions: While the precise mechanism of action remains unknown, our results demonstrated that OPZ exerted a protective role in the UUO-mediated renal fibrosis rat model highlighting a promising therapeutic potency of Nrf2-activators for alleviating the detrimental effects of unilateral obstruction in kidneys.

Expression of intronic miRNAs and their host gene Igf2 in a murine unilateral ureteral obstruction model

The objective of this study was to determine the expression of miR-483 and miR-483* and the relationship among them, their host gene (Igf2), and other cytokines in a murine model of renal fibrosis. The extent of renal fibrosis was visualized using Masson staining, and fibrosis was scored 3 days and 1 and 2 weeks after unilateral ureteral obstruction (UUO). Expression of miR-483, miR-483* and various cytokine mRNAs was detected by real-time polymerase chain reaction (PCR). Expression of miR-483 and miR-483* was significantly upregulated in the UUO model, particularly miR-483 expression was the greatest 2 weeks after surgery. Additionally, miR-483 and miR-483* expression negatively correlated with Bmp7 expression and positively correlated with Igf2, Tgfβ, Hgf, and Ctgf expression, as determined by Pearson's correlation analysis. Hgf expression significantly increased at 1 and 2 weeks after the surgery compared to the control group. This study showed that miR-483 and miR-483* expression was upregulated in a murine UUO model. These data suggest that miR-483 and miR-483* play a role in renal fibrosis and that miR-483* may interact with miR-483 in renal fibrosis. Thus, these miRNAs may play a role in the pathogenesis of renal fibrosis and coexpression of their host gene Igf2.

Long-Term Follow-up Results of Laparoscopic Pyeloplasty

PURPOSE: To assess the long-term follow-up results of laparoscopic pyeloplasty for ureteropelvic junction obstruction. MATERIALS AND METHODS: Sixty-five patients (mean age, 43.8 years) who underwent standard laparoscopic pyeloplasty by transperitoneal approaches were enrolled in this study. The chief complaint was flank pain (n=57 patients); the remaining cases were detected incidentally. Twenty-three patients had undergone previous abdominal surgeries, including open pyeloplasty and endopyelotomy. Mean stricture length was 1.06 cm. Grade 3/4 and 4/4 hydronephrosis was detected in 36 and 14 patients, respectively. An obstructive pattern was present on the renal scan in 53 patients (81.5%). RESULTS: Fifty-seven patients were treated with dismembered Anderson-Hynes pyeloplasty and eight patients with Fenger pyeloplasty. During the operation, crossing vessels were found in 27 patients (41.5%). Mean operating time was 159.42 minutes. Although there were no cases of open conversion, two patients with colon and spleen injuries were detected postoperatively. The mean starting time of postoperative ambulation and diet was 1.54 days and 1.86 days, respectively. Mean hospital stay was 8.09 days. Mean follow-up period was 36.5 months. Follow-up intravenous pyelography and renal scan showed improvements in 59 patients, and the radiologic success rate was 90.8%. Eight patients showed failure on radiologic or symptomatic evaluation, and the overall success rate was 87.7%. In the comparative analysis between the success and failure groups, drained amount was the only risk factor related to failure (554.41 mL. vs. 947.70 mL, p=0.024). CONCLUSIONS: Long-term follow-up results support laparoscopic pyeloplasty as the standard treatment for ureteropelvic junction obstruction. Drained amount is a risk factor for failure of the operation.

Dermatan sulfate reduces monocyte chemoattractant protein 1 and TGF-β production, as well as macrophage recruitment and myofibroblast accumulation in mice with unilateral ureteral obstruction

Selectins play an essential role in most inflammatory reactions, mediating the initial leukocyte-rolling event on activated endothelium. Heparin and dermatan sulfate (DS) bind and block P- and L-selectin function in vitro. Recently, we reported that subcutaneous administration of DS inhibits colon inflammation in rats by reducing macrophage and T-cell recruitment and macrophage activation. In the present study, we examined the effect of porcine intestinal mucosa DS on renal inflammation and fibrosis in mice after unilateral ureteral obstruction (UUO). Twenty-four adult male Swiss mice weighing 20-25 g were divided into 4 groups: group C (N = 6) was not subjected to any surgical manipulation; group SH (N = 6) was subjected to surgical manipulation but without ureter ligation; group UUO (N = 6) was subjected to unilateral ureteral obstruction and received no treatment; group UUO plus DS (N = 6) was subjected to UUO and received DS (4 mg/kg) subcutaneously daily for 14 days. An immunoblot study was also performed for TGF-β. Collagen (stained area ~3700 µm²), MCP-1 (stained area ~1700 µm²), TGF-β (stained area ~13 percent of total area), macrophage (number of cells ~40), and myofibroblast (stained area ~1900 µm²) levels were significantly (P < 0.05) higher in the UUO group compared to control. DS treatment significantly (P < 0.05) reduced the content of collagen (stained area ~700 µm²), MCP-1 (stained area ~160 µm²) and TGF-β (stained area ~5 percent of total area), in addition to myofibroblast (stained area ~190 µm²) and macrophage (number of cells ~32) accumulation in the obstructed kidney. Overall, these results indicate that DS attenuates kidney inflammation by reducing macrophage recruitment, myofibroblast population and fibrosis in mice submitted to UUO.

Multiple, Bilateral Fibroepithelial Polyps Causing Acute Renal Failure in a Gastric Cancer Patient

We report a case of primary fibroepithelial polyps (FEPs) in the middle of both ureters in a patient with advanced gastric cancer and acute renal failure. Ureteral FEPs are rare benign lesions, and multiple, bilateral lesions are extremely rare. To our knowledge, this report is the seventh case of bilateral FEPs in the literature. Our case has clinical implications because FEPs should be considered as a cause of ureteral obstruction inducing acute renal failure in advanced gastric cancer.

Renal parenchyma thickness: a rapid estimation of renal function on computed tomography

Purpose: To define the relationship between renal parenchyma thickness (RPT) on computed tomography and renal function on nuclear renography in chronically obstructed renal units (ORUs) and to define a minimal thickness ratio associated with adequate function. Materials and Methods: Twenty-eight consecutive patients undergoing both nuclear renography and CT during a six-month period between 2004 and 2006 were included. All patients that had a diagnosis of unilateral obstruction were included for analysis. RPT was measured in the following manner: The parenchyma thickness at three discrete levels of each kidney was measured using calipers on a CT workstation. The mean of these three measurements was defined as RPT. The renal parenchyma thickness ratio of the ORUs and non-obstructed renal unit (NORUs) was calculated and this was compared to the observed function on Mag-3 lasix Renogram. Results: A total of 28 patients were evaluated. Mean parenchyma thickness was 1.82 cm and 2.25 cm in the ORUs and NORUs, respectively. The mean relative renal function of ORUs was 39 percent. Linear regression analysis comparing renogram function to RPT ratio revealed a correlation coefficient of 0.48 (p < 0.001). The linear regression equation was computed as Renal Function = 0.48 + 0.80 * RPT ratio. A thickness ratio of 0.68 correlated with 20 percent renal function. Conclusion: RPT on computed tomography appears to be a powerful predictor of relative renal function in ORUs. Assessment of RPT is a useful and readily available clinical tool for surgical decision making (renal salvage therapy versus nephrectomy) in patients with ORUs.

Estudo histopatológico renal pós-ligadura uretral em cäes / Renal histopathological study after uretral ligadure in dogs

Os autores realizaram um trabalho experimental em caes onde foi efetuada ligadura ureteral em junçao uretero-pélvica (J.U.P.), analisando semenalmente as alteraçoes histopatológicas renais. Foram observadas alteraçoes fibróticas e dilataçao tubular renal nas primeiras duas semanas pós-ligadura ureteral. Concluímos que a partir da 3ª semana houve alteraçao glomerular, observando-se atrofia renal completa na 5ª semana, necessitando-se de urgência na reversao do quadro.