Ureteral Ligation Research Articles

Urological anomalies associated with obstructed hemivagina and ipsilateral renal anomaly (OHVIRA) syndrome, a case series

Abstract We report four patients with obstructed hemivagina and ipsilateral renal anomaly (OHVIRA) syndrome associated with a urological anomaly other than typical renal agenesis. Three patients had a dysplastic kidney and an ectopic ureter to the vagina, and one had a vesicovaginal fistula. Although the timing of surgery differed, all patients underwent vaginal septum resection. The vesicovaginal fistula was repaired laparoscopically, and the patient was asymptomatic one year later. In the remaining three patients, resection of the dysplastic kidney and ureteral ligation were both effective procedures for the management of urine drainage from the vagina. These anomalies originate from abnormal development of the Wolffian and Mullerian ducts. Knowledge of these variants is essential for effective preoperative investigation and surgical planning.

Expression of EphrinA1, vascular endothelial growth factor and microRNA-210 after hydronephrosis

Objective To investigate the difference and correlations of the EphrinA1, vascular endothelial growth factor (VEGF) expression and microRNA (miRNA)-210 in the kidney tissue of rats in the unilateral ureteral obstruction (UUO) model. And to understand the regulation mechanism of the three factors in the occurrence of renal tissue injury in rats. Methods Using unilateral ureteral ligation to establish a model of hydronephrosis in mice (except for the NC group), and they wrere randomly divided into an acute hydronephrosis group (UUO group) and a false surgical control group (NC group). The UUO group was divided into four groups (UUO 2 d group, UUO 5 d group, UUO 9 d group, and UUO 14 d group), and eight mice in each group. The pathological changes of renal tissue were observed by hematoxylin-eosin (HE) staining. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the mRNA expression of EphrinA1, VEGF and miRNA-210; Western blot was used to detect the protein expression of EphrinA1 and VEGF. Resulsts Hydronephrosis was not shown in the NC group, and hydronephrosis and inflammatory cell infiltration were observed in the UUO group. Compared with NC group, the mRNA expression of EphrinA1 , VEGF and miRNA-210 were up-regulated in UUO 2 d group (P<0.05). With the extension of the time of hydronephrosis, the expressions of all three factors were down-regulated in 9 d and 14 d groups compared with 2 d and 5 d groups, and reached the lowest point at 14 d (P<0.05); Western blot result indicated that the expression of EphrinA1 and VEGF in renal tissue of UUO 2 d and 5 d group was increased compared with NC group (P<0.05). Conclusions The UUO mouse model verified that miRNR-210 participated in hydronephrosis. The consistency of EphrinA1, VEGF, and miRNA-210 indicated that the three factors played an important role in the occurrence and development of UUO. Key words: Hydronephrosis; Ephrin-A1; Vascular endothelial growth factor; MicroRNAs; Mice

Effect of erythropoietin on the expression of aquaporin 2-3 after the release of unilateral ureter obstruction in young rats

Objective To investigate the effect of erythropoietin (EPO) on the expression of aquaporin 2-3 after the release of unilateral ureter obstruction in young rats. Methods Twenty-four SD rats were randomly divided into 3 groups(CUUO-R group, CUUO-R+ EPO group and sham group, with 8 rats in each group). The CUUO-R model was built through unilateral ureteral ligation, after 48 h the obstruction was released.EPO was given to the CUUO-R+ EPO group at the time point of removing obstruction, and then repeated every other day for 1 week, and the same volume of saline was simultaneously given to the CUUO-R rats.The rats in sham group experienced the laparotomy and free dissection of left ureter but not ligation.The kidneys were harvested 7 d after the release of CUUO.The methods of Western blot and immunohistochemistry were used to examine the effects of erythropoietin on the expression of AQP2 and AQP3. Results The osmotic pressure of CUUO-R+ EPO group was higher than those of CUUO-R group, but lower than that of sham group(P=0.007). The concentration of creatinine and urea in the CUUO-R group[(58.001±2.416) μmol/L and (9.025±1.158) mmol/L]were higher than those of CUUO-R+ EPO group [(57.072±2.286) μmol/L and (1.479±0.043) mmol/L] and sham group [(54.820±1.536) μmol/L and (6.929±0.604) mmol/L]. The differences of the concentration of creatinine and urea between CUUO-R group and sham group were statistically significant(P 0.05). The immunohistochemistry showed that the expressions of AQP2 and AQP3 in co-llecting duct in CUUO-R group were significantly weaker than those of in sham group, and the expression of those in CUUO-R+ EPO group were slightly weaker than sham group.These results were further confirmed by Western blot, as the relative quantity of AQP2 and AQP3 were also the lowest in CUUO-R group(AQP2 in 3 groups were 0.974±0.109, 1.923±0.097 and 2.002±0.044, F=392.4, P=0.000; AQP3 in 3 groups were 0.941±0.048, 1.497±0.043 and 1.863±0.043, F=735.8, P=0.000). Conclusions EPO treatment is beneficial for the recovery expre-ssion of AQP2 and AQP3 as well as renal function at the early period after the release of ureteral obstruction in young rats. Key words: Erythropoietin; Ureter obstruction; Aquaporin 2-3; Rats

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

BackgroundUreteral 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).MethodsUUO 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.ResultsThe 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.ConclusionThese 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.

SAT-133 A novel, phosphorescence-based technique to assess urinary oxygen tension

Renal hypoxia aggravates acute kidney injury and accelerates chronic kidney disease. Recently, the importance of urinary bladder oxygen tension, employed as a window of renal oxygen tension, has been shown in patients under cardiac surgery in the point that low urinary oxygen tension predicts postoperative acute kidney injury (Zhu MZL et al. Nephrol Dial Transplant 2018). However, measurement technique of urinary oxygen tension in murine is not established. Phosphorescence is a light which has unique character whose lifetime is inversely correlated to oxygen concentration, and we established oxygen tension measurement method at renal surface using phosphorescence (Hirakawa Y et al Sci Rep 2016, Hirakawa Y et al. Kidney Int 2018). This time we applied phosphorescence to urinary bladder oxygen tension measurement. The aim of this study is to establish a novel method to measure urinary oxygen tension, and to examine factors influencing urinary oxygen tension Balb/c mice were used in this research. A water-soluble small-molecule phosphorescent dye, BTP-PEG24, was administered via tail vein injection. Phosphorescence lifetime was measured by quantaurus-tau by Hamamatsu Photonics with two-branched optical fiber. Results of phosphorescence lifetime measurement were shown as mean ± standard deviation. Both of fluorescence stereoscopy and phosphorescence lifetime imaging microscopy revealed that this phosphorescent dye was rapidly excreted into urine and accumulated in the urinary bladder. Phosphorescence lifetime measurement was done after median incision in lower abdomen and placement of two-branched optical fiber near the urinary bladder. After BTP-PEG24 administration, phosphorescence lifetime was measured in normoxia, general hypoxia by 10% oxygen inhalation, and reoxygenation by return to room air inhalation, and phosphorescence lifetime changed from 2.18±0.15μs to 2.51±0.22μs (hypoxia) and 2.08±0.12μs (reoxygenation). The phosphorescence lifetime measurement could be done after the ligation of both ureters, and the value changed from 1.92±0.08μs to 2.11±0.17 (hypoxia) and 1.88±0.11μs (reoxygenation). Considering that shorter phosphorescence lifetime means higher oxygen tension, ligation of both ureters raised oxygen tension of bladder urine, which meant oxygen tension in pelvic urine was indeed affected by renal oxygenation. However, at least in part, the oxygen tension in pelvic urine was indicated to reflect the oxygen tension of bladder epithelia, since the phosphorescence lifetime changes according to oxygen concentration of inspired air. The results of phosphorescence lifetime measurement in urinary bladder with BTP-PEG24 were shown. Each “21%”, “10%”, and “Re21%” indicates normoxia, hypoxia, and reoxygenation, respectively. The dots with same color were obtained from the same mouse. N = 4 for sham group and N = 5 for ligation group. Each mouse underwent three phosphorescence lifetime measurements. We established novel technique to assess pelvic urine oxygen tension. Pelvic urine oxygen tension was shown to be influenced by both of oxygen tension in kidney and in bladder epithelia. Therefore, fresh urine, which might remain unaffected by bladder epithelia oxygenation, must be used as the window of renal oxygenation.

SUN-157 Combined Cell Therapy with Serelaxin Reduces Established Renal Inflammation and Fibrosis Following Obstructive Nephropathy

We had previously shown that the anti-fibrotic and organ-protective effects of the hormone-based drug, Serelaxin (RLX), could enhance the therapeutic effects of human bone marrow-derived mesenchymal stem cells (MSCs) in attenuating ureteral obstruction (UUO)-induced renal disease. However, as MSCs were directly administered to the obstructed kidney of anaesthetised mice via intrarenal vein injection, we investigated intravenous (i.v) administration of MSCs (representing a more clinically-feasible route of delivery) in combination with RLX, as an intervention therapy. 7-8 week old male C57B6J mice were subjected to UUO via ligation of the left ureter. Sub-groups of mice (n=6/group) were then administered 1x106 MSCs alone (via i.v-injection); 0.5mg/kg/day RLX alone (via osmotic mini-pumps, which allowed for its continuous infusion into the circulation of treated animals); or the combined effects of 1x106 MSCs and 0.5mg/kg/day RLX after 3 days of UUO (when fibrogenesis could be measured). A separate sub-group of mice also received 0.5mg/kg/day RLX at the time of UUO injury, and 1x106 MSCs-i.v 3 days later. Sham-operated control and UUO-injured mice that were left untreated were included as controls, while all mice were killed after 10 days of UUO for tissue collection and the analysis of renal damage, inflammation and fibrosis. UUO-injured mice underwent significant renal damage, inflammation, TGF-b1 expression levels, myofibroblast differentiation and interstitial extracellular matrix (ECM) deposition and collagen concentration (as measures of fibrosis) (all p<0.01 vs sham controls). Compared to the effects of either MSCs or RLX alone, which demonstrated modest anti-fibrotic effects in the absence of any marked anti-inflammatory effects, the combined effects of MSCs and RLX significantly reduced established UUO-induced renal inflammation, fibrosis and damage; particularly when RLX was administered 3 days prior to MSC administration (all p<0.05 vs UUO alone). The combined therapy also significantly increased collagen-degrading MMP-9 activity over the effects of UUO alone, MSCs alone or RLX alone (all p<0.05 vs UUO, UUO+MSCs or UUO+RLX). These findings demonstrated that combining MSCs with RLX provide improved renoprotection over the effects of either therapy alone against obstructive nephropathy, and may represent a viable intervention therapy for treating established renal fibrosis. RLX pre-treatment appeared to provide added benefits in improving the environment for the accessibility and therapeutic efficacy of administered MSCs, compared to its co-treatment with these stem cells.

SAT-192 LOSS OF MACROPHAGE-SPECIFIC TLR4 INHIBITS OBSTRUCTIVE RENAL FIBROSIS BY BLOCKING MACROPHAGE-TO-MYOFIBROBLAST TRANSITION VIA A BAMBI-DEPENDENT MECHANISM

Macrophages are a key inflammatory cell that plays a critical role in acute and chronic kidney diseases. Toll-like receptor (TLR) 4 is highly expressed on inflammatory macrophages and has been shown to trigger acute renal inflammation. However, the role of macrophage-specific TLR4 in progression of chronic kidney disease remains unclear, which was investigated in the present study in a mouse model of unilateral ureter ligation (UUO). A mouse model of UUO was induced in Tlr4flox/floxand lysozyme Mpromoter-driven cre(LysM-cre) transgenic mice (C57BL/6). Role and mechanisms of TLR4 in macrophage-mediated renal fibrosis were studied. UUO led to remarkably F4/80+macrophage and CD3+/CD4+T cell infiltration and progressive renal fibrosis in Tlr4flox/floxmouse kidney. In contrast, deletion of macrophage-specific TLR4 blunted these inflammatory responses in LysM-cre/Tlr4flox/flox animals. Mechanistically, these inhibitory effects on renal inflammation and fibrosis in LysM-cre/Tlr4flox/floxmice were associated with the shift of macrophages from M1 (F4/80+/iNOS+) to M2 phenotype (F4/80+/CD206+). Most importantly, we also found that deletion of TLR4 from macrophage largely suppressed progressive renal fibrosis by inhibiting macrophage-to-myofibroblast transition (MMT) as identified by F4/80+αSMA+cells. This novel observation suggests that macrophage-TLR4 may trigger inflammatory M1 macrophage activation and subsequent transition to the fibrogenic phenotype via the MMT process. Further studies revealed that BMP and activin membrane-bound inhibitor (Bambi), a TGF-β1 pseudoreceptor that competitively inhibits the binding of active TGF-β1 to receptor, was also highly upregulated in LysM-cre/Tlr4flox/floxmouse kidney after UUO. Thus, macrophages lacking TLR4 showed an anti-inflammatory and anti-fibrotic phenotype as demonstrated by high levels of Bambi but low levels of TGF-b/Smad3 signaling, MMT, and renal fibrosis in vivoand in vitro. Deletion of macrophage-specific TLR4 ameliorates obstructive renal injury by promoting anti-inflammatory macrophage polarization and inhibiting MMT-mediated renal fibrosis via a Bambi-dependent mechanism. Results from this study suggest that targeting the macrophage-specific TLR4 pathway may represent a novel therapeutic intervention for renal inflammation and fibrosis.

Use of subcutaneous ureteral bypass systems as a bridge to definitive ureteral repair in a cat with bilateral ureteral ligation secondary to complicated ovariohysterectomy

A kitten presented with acute kidney injury, bilateral hydronephrosis and proximal hydroureter, three days following bilateral ureteral ligation, during a complicated ovariohysterectomy procedure. Clinical signs were anorexia, lethargy, weakness, hypothermia,...

Inner Medullary Urea Transporters Contribute to Development of Renal Fibrosis in Mice With Unilateral Ureteral Obstruction

Fourteen percent of the population of the United States is affected by chronic kidney disease (CKD). Although the mechanisms that are responsible for CKD remain unclear, there are many clinical and animal studies showing that low protein diets reduce the long term effects of CKD. One possible explanation for these benefits is the restricted urea load of the low protein diet suggesting a role for the urea transporters in this process. Unilateral ureteral obstruction (UUO) is a well known model to produce fibrogenic responses such as increased capillary macrophages, pro‐fibrogenic proteins, interstitial matrix, myofibroblasts, etc. in CKD rodents. We hypothesized that the urea transporters contribute to the development of renal fibrosis. We used UUO mice receiving a maximal urea load (high protein diet) to investigate contributions of urea transporters to renal fibrosis. C57Bl6 mice ± genetic ablation of UT‐A1 and UT‐A3 urea transporters (UT‐A1/A3 KO) underwent UUO surgery (ligation of the left proximal ureter). Four days after surgery mice were given a high (40%) protein diet for 10 further days. Mice were killed and obstructed kidneys collected for protein and histochemical analysis. All of the obstructed kidneys showed evidence of hydronephrosis after 14 days. BUN was unchanged by UUO: WT control: 44.2 mg/dl, WT UUO: 46.8 mg/dl, KO control: 43.4, KO UUO: 47.1. TGF‐b was increased in both WT and UT‐A1/A3 KO mice with UUO (302% and 389% respectively). WT with UUO showed a 320% increase in α‐SMA vs mice without UUO. UT‐A1/A3 KO mice with UUO showed a blunted 271% increase in α‐SMA vs unobstructed UT‐A1/A3 KO mice. Vimentin, another marker of fibrosis, was significantly increased 555% by UUO (vs no UUO). UUO in UT‐A1/A3 KO mice did not increase vimentin. H&amp;E staining revealed similar infiltration of inflammatory cells in both UUO WT and UUO UT‐A1/A3 KO mice. Trichrome staining showed higher collagen levels in UUO WT vs UUO UT‐A1/A3 KO mice. Immunohistochemical staining for αSMA and vimentin revealed higher levels in UUO WT vs UUO UT‐A1/A3 KO mice. These data suggest that urea transporters do not prevent inflammation caused by UUO. However, the overall development of fibrosis in UUO mice fed a high protein diet is attenuated by the absence of urea transporters suggesting that urea reabsorption by urea transporters contributes to renal fibrosis. If urea transport inhibitors replicate the effects of genetic knock out, they may represent a promising future therapy.Support or Funding InformationRelypsa Nephrology and Cardiology Fellowship Grant;NIH RO1 DK41707This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Ureteral clipping for the treatment of a non-functioning upper kidney moiety associated with a massive ureterocele: step-by-step description of a novel technique

The objective of this video is to illustrate feasibility of the ureteral ligation for the treatment of massive ureteroceles associated with non-functioning upper kidney moieties in duplex kidneys. In this video, one case is presented to demonstrate this novel technique. A nine-year-old boy presented with progressive lower urinary tract symptoms. Radiological workup depicted a duplex kidney on the left side with the absence of function on the upper pole and hydroureteronephrosis with a massive ureterocele. Laparoscopic ureteral transection, drainage, and ligation of both extremities of the enlarged ureter (upper pole ureter) were performed. Immediately after ureteral ligation, ultrasonic evidence of ureterocele decompression and improved hydroureteronephrosis was observed. This patient remained asymptomatic without postoperative complications after 3 years. De novo reflux was not observed. Ureteral ligation, as demonstrated in the video, is a good approach for the treatment of massive ureteroceles associated with non-functioning upper kidney moieties in duplex kidneys. Compared with the current standard techniques (incision/puncture), ureteral ligation has the clear advantage of not causing 'de novo reflux' or unsuccessful de-obstruction, and is not as surgically demanding as other reconstructive/ablative techniques. The disadvantage is the need of regular clinical and ultrasonographic follow-up.

Reduced asymmetric dimethylarginine accumulation through inhibition of the type I protein arginine methyltransferases promotes renal fibrosis in obstructed kidneys.

The role of asymmetric dimethylarginine (ADMA) in chronic kidney disease (CKD) is unclear. Through inhibition of type I protein arginine methyltransferases (PRMTs), a novel strategy, we aimed to determine the effect of ADMA on renal fibrosis and explore its underlying working mechanisms. After sham or unilateral ureter ligation (UUO) operation, 20-25 g male c57 mice were treated with vehicle or PT1001B, an inhibitor of type I PRMTs, for 13 d. Moreover, human kidney 2 (HK2) and normal rat kidney 49F (NRK-49F) cells were treated with various concentrations of PT1001B or ADMA in the presence of 2.5 ng/ml TGF-β. We found that treatment with PT1001B increased the deposition of extracellular matrix proteins, the expression of α smooth muscle actin, and connective tissue growth factor in UUO-induced fibrotic kidneys, which is correlated with reduced expression of PRMT1, reduced the production of ADMA, and increased expression of uromodulin. In TGF-β-stimulated HK2 and NRK-49F cells, PT1001B dose-dependently inhibited ADMA production, increased NO concentrations, and enhanced the expression of profibrotic proteins. Exogenous addition of ADMA inhibited the expression of profibrotic proteins dose-dependently and attenuated the profibrotic effect of PT1001B. Moreover, ADMA reduced the NO concentration in PT1001B-treated HK2 cells. Finally, we conclude that ADMA has an antifibrotic effect in obstructed kidneys, and future application of type I PRMT inhibitor should be done cautiously for patients with CKD.-Wu, M., Lin, P., Li, L., Chen, D., Yang, X., Xu, L., Zhou, B., Wang, C., Zhang, Y., Luo, C., Ye, C. Reduced asymmetric dimethylarginine accumulation through inhibition of the type I protein arginine methyltransferases promotes renal fibrosis in obstructed kidneys.

Eplerenone Ameliorates Cell Pyroptosis in Contralateral Kidneys of Rats with Unilateral Ureteral Obstruction

Background: The progression of chronic renal failure in patients with unilateral renal injury is associated with loss of function in the contralateral kidney, but the molecular mechanism remains unclear. The activation of mineralocorticoid receptor (MR) in the kidney contributes to renal cell damage, leading to apoptosis, pyroptosis, and necrosis. Pyroptosis is a programmed cell death induced by caspase-1, which is usually activated by nod-like receptor pyrin-containing 3 (NLRP3) inflammasomes. Our study aimed to investigate the effects of eplerenone (EPL) on cell pyroptosis in the contralateral kidneys of unilateral ureteral obstruction (UUO) rats. Methods: Sprague-Dawley rats were randomly divided into 3 groups: sham group, UUO group (10 days of left ureter ligation), and UUO treated with EPL (UUO + EPL) group. The contralateral kidneys of all rats were collected for studies. Results: We observed evidently increased number of pyroptosis cells in the contralateral kidneys of UUO rats compared to those from Sham rats. The expression of NLRP3, caspase-1, interleukin-1β, serum and glucocorticoid-inducible protein kinase-1, and nuclear factor kappa B were also upregulated in the contralateral kidneys of UUO rats compared to Sham kidneys, and these effects were reduced by MR blocker EPL. Conclusion: Our data suggest that the activation of MR is involved in NLRP3/caspase-1 pathway-induced cell pyroptosis in the contralateral kidney of UUO model.

Microvesicles containing miR-34a induce apoptosis of proximal tubular epithelial cells and participate in renal interstitial fibrosis.

Function and potential mechanism of microvesicles (MVs) containing microRNA34a in renal interstitial fibrosis were investigated. A rat model of renal interstitial fibrosis was established by unilateral ureteral ligation (UUO). Rat proximal tubular epithelial cell line (NRK-52E) was used to explore the effect of MVs containing microRNA-34a on tubular epithelial cells during fibrosis, which were secreted by tubulointerstitial fibroblasts. Regardless of the UUO renal interstitial fibrosis model, or the TGF-β1-treated renal tubular epithelial cells, microRNA-34a was increased in the MVs secreted by tubulointerstitial fibroblasts. miR-34a could be transmitted through the damaged tubule basement membrane to proximal tubular epithelial cells, where it induced apoptosis of renal tubular epithelial cells by inhibiting the expression of Bcl-2, further aggravating renal interstitial fibrosis. MicroRNA-34a secreted by damaged renal interstitial fibroblasts can promote renal tubular epithelial cell apoptosis and participate in renal interstitial fibrosis by inhibiting Bcl-2.

Deteksi Hidroureter pada Tikus Pasca Obstruksi Ureter Unilateral Medial dan Distal Menggunakan Ultrasonografi Frekuensi 10 MHz

Unilateral ureteral obstruction can occur in all animals and it is located proximal, medial and distal. Obstruction causes abnormalities in ipsilateral ureters in the form of hydrouterers. The aim of this study was to detect hydroureters in post-unilateral medial and distal ureteric rats using a 10 MHz ultrasonography frequency. Thirty-six female Sprague Dawley rats aged 3 months were divided into 3 treatment groups. Each group consisted of 12 individuals. Group I as a control received laparotomy treatment. Group II laparotomy with medial right-hand ureteral ligation and group III with right distal ureteral ligation. Three rats taken randomly from each group at weeks 1, 2, 3 and 4 post-ligation is then performed ultrasonography. The results of ultrasonography were analyzed descriptively, comparatively but ureteral diameter were analyzed using statistical of 3x4 factorial patterns. Ultrasound examination showed that ligation in one ureter caused rat undergoing unilateral ureteral obstruction and hidroureter. The diameter of the ureter with a hydroureter has increased from the 1st to 4th week. The increase occurs because the urine in the lumen cannot be excreted. The contralateral ureter remains normal and cannot be observed. The conclusion of the study is that hydroureter in rats can be detected using the frequency of 10 MHz ultrasonography which is characterized by anekoic tubular formation posterior to the right kidney. The unilateral ureteral obstruction has no effect on the contralateral ureter because it is still able to compensate for the performance of the ipsilateral ureter that has a hydroureter. The difference in the location of ligation and time of examination affect the increase in ipsilateral ureteral diameter.

The protective role of intermedin in promoting angiogenesis during renal fibrosis

BackgroundRenal fibrosis promotes the progression of chronic renal disease to end-stage renal disease. Microvascular damage and loss play an important role in renal fibrosis. Intermedin (IMD) is expressed mainly in the heart and kidney. IMD has been shown to increase renal blood flow and reduce the loss of glomerular and surrounding renal tubules, but its role in mediating microvascular damage in renal fibrosis remains to be elucidated. Here, we investigated the effects of IMD on microvascular damage in a renal fibrosis model. MethodsWe created a rat model of unilateral ureteral obstruction (UUO) to clarify the effect of microvascular damage on renal fibrosis and the effect of intermedin on reversing renal vascular injury and promoting angiogenesis. Rats were divided randomly into three groups: sham, UUO, and UUO + IMD. The sham group underwent free ureteral ligation but not occlusion. Rats in the latter two groups underwent UUO, and rats in the IMD group were additionally administered intermedin (100 ng/kg/h) daily. On the 7th, 14th, 21st, and 28th days after surgery, abdominal aortic blood and the obstructed kidneys were harvested from the rats (n = 6) for analysis. ResultsIMD was found to protect against renal vascular injury and to increase microvessel density. Molecularly, IMD upregulated vascular endothelial growth factor–vascular endothelial growth factor receptor (VEGF–VEGFR2) pathway activity. The VEGF–VEGFR2 pathway might be the underlying mechanism mediating the protective activities of IMD in promoting angiogenesis, delaying renal fibrosis, and improving renal function. ConclusionIMD could be a potential candidate treatment for renal fibrosis.

Multiple refinements to the anaesthetic protocol for laparoscopic orthotopic kidney auto-transplantation in a pig model.

Fifty-four pigs ( Sus scrofa, Large White cross) from a commercial pig farm were anaesthetised over a six-year period from October 2011. The procedural stages included initial instrumentation for intra-operative monitoring, laparoscopic nephrectomy, preparation of the kidney graft, orthotopic auto-transplantation by either a laparoscopic approach or an open surgical approach, and ligation of the contralateral ureter. During the evolution and establishment of this pig model multiple refinements were introduced: (1) a heat pad was changed to a circulating warm air blanket; (2) routine administration of anticholinesterase and antimuscarinic drugs for reversal of neuromuscular blockade; (3) a technique for urethral catheterisation was developed; (4) ultrasound guidance for placement of a central venous line was learned; (5) intravenous infusions of morphine and ketamine were instituted for a more stable and balanced anaesthetic protocol; and (6) post-operative monitoring was performed by two technical staff for at least the first six hours after extubation of the trachea. The combination of refinements to the anaesthesia protocol for laparoscopic orthotopic kidney auto-transplantation over the first 54 pigs has translated to improved outcomes. This conclusion is entirely subjective as accurate measurement of the impact of each refinement is impossible. Nevertheless, refinement is a continuous process and should be applied to the entire range of procedures involved in animal use for scientific purposes.

Nigella sativa extract is a potent therapeutic agent for renal inflammation, apoptosis, and oxidative stress in a rat model of unilateral ureteral obstruction.

Unilateral ureteral obstruction (UUO) is a well-established experimental model to evaluate renal interstitial fibrosis. Current study is aimed to investigate the effects of Nigella sativa (NS) extract and renin-angiotensin system (RAS) blockade against kidney damage following UUO in rats. In this study, the rats received intraperitoneal injection of losartan (15mg/kg), captopril (30mg/kg), and two doses of NS extract (200 and 400mg/kg) for 18 consecutive days. At the fourth day of the experiment, laparotomy was performed, and the left ureter was ligated. Sham-operated animals received saline as vehicle, and laparotomy without ureteral ligation was done. UUO was associated with significant increase in the expression of renal angiotensin II and monocyte chemoattractant protein-1, concentration of malondialdehyde and tumor necrosis factor-α, and the number of apoptotic cells when compared with sham group. Renal total thiol content and the activity of antioxidant enzymes were significantly reduced as compared with the sham group. However, treatment of obstructed rats with losartan, captopril, and NS extract significantly improved these renal impairments when compared with UUO group. Thus, NS extract, a potent antioxidant and anti-inflammatory herb, is a therapeutic agent to treat the UUO-induced kidney damage comparable with the well-known RAS inhibitors captopril and losartan.

Human umbilical cord-derived mesenchymal stem cells conditioned medium attenuate interstitial fibrosis and stimulate the repair of tubular epithelial cells in an irreversible model of unilateral ureteral obstruction.

The growing number of patients suffering from chronic renal disease (CKD) is a challenge for the development of innovative therapies. Researchers have studied the therapeutic effects of cell therapy in acute kidney injury (AKI). However, the therapeutic effect of conditional medium (CM) in the CKD models have been rarely reported. Here, we examined the effects of umbilical cord derived-mesenchymal stem cells (hUC-MSCs) CM on renal fibrosis in a rat model of unilateral ureteral obstruction (UUO). Animals were randomly divided into three groups: sham-operated, UUO, UUO + CM. CM was administered via the left renal artery after total ligation of the left ureter. Rats were killed after 14 days of obstruction. Histological changes and oxidative stress parameters were assessed. Western blotting and immunohistochemistry analysis were used to measure epithelial-mesenchymal transition (EMT) markers, including epithelial cadherin (E-cadherin), α-smooth muscle actin (α-SMA), tumour necrosis factor-α (TNF-α), Collagen-I, and transforming growth factor β1 (TGF-β1). Proliferation and apoptosis of renal tubular epithelial cells (RTEs) were also measured. HucMSC-CM significantly reduced the levels of malondialdehyde (MDA) and reactive oxygen species (ROS), and increased the activity of glutathione (GSH) induced by UUO. Moreover, CM significantly reduced the expression of TGF-β1, α-SMA, TNF-α and Collagen-I in UUO kidney, promoted the proliferation of RTEs and inhibited its apoptosis. In addition, the increased expression of E-cadherin also reflects the effective improvement of renal interstitial fibrosis. This study shows that CM protects UUO-induced kidney damage and therefore could be a potential tool to prevent CKD progression.

The uroplakin plaque promotes renal structural integrity during congenital and acquired urinary tract obstruction.

Urinary tract obstruction represents a common cause of kidney injury across the human life span, resulting in chronic kidney disease and end-stage renal disease. Yet, the extent of obstructive renal damage can be heterogeneous between individuals, implying the existence of unknown mechanisms that protect against or accelerate kidney injury. In this study, we investigated the role of urothelial remodeling in renal adaptation during congenital and acquired obstruction. In the Megabladder ( Mgb-/-) model of congenital obstruction and unilateral ureteral ligation model of acute obstruction, progressive hydronephrosis is strongly associated with dynamic reorganization of the renal urothelium, which elaborates a continuous uroplakin (Upk) plaque. This led us to postulate that the Upk plaque prevents parenchymal injury during urinary tract obstruction. To test this hypothesis, we interbred Mgb-/- and Upk1b-/- mice, which lack the critical Upk1b subunit for Upk plaque formation. Upk1b-/-; Mgb-/- mice experienced an accelerated onset of bilateral hydronephrosis with severe (>67%) parenchymal loss, leading to renal failure and mortality in adolescence. To investigate the function of the renal Upk plaque during acute obstruction, we destabilized the Upk plaque by Upk1b deletion or genetically depleted Upk+ cells following unilateral ureteral obstruction. Both of these strategies accelerated renal parenchymal loss following ureteral ligation, attesting to a conserved, stabilizing role for Upk plaque deposition in the acutely obstructed kidney. In aggregate, these complementary experiments provide the first evidence that the Upk plaque confers an essential, protective adaptation to preserve renal parenchymal integrity during congenital and acquired urinary tract obstruction.

PNaKtide ameliorates renal interstitial fibrosis through inhibition of sodium-potassium adenosine triphosphatase-mediated signaling pathways in unilateral ureteral obstruction mice.

Sodium-potassium adenosine triphosphatase (Na/K-ATPase) has been shown to regulate Src activity by combining with Src to keep it in an inactive form. We previously reported that Na/K-ATPase was downregulated in unilateral ureteral obstruction (UUO) animals. In this study, we examined whether inhibition of Na/K-ATPase-mediated Src signaling pathways ameliorated renal interstitial fibrosis induced by UUO. UUO was performed on male C57BL/6J mice. pNaKtide, a mimic of Na/K-ATPase, was administered by intraperitoneal injection on Day 0 and Day 4 after ureteral ligation. Markers of interstitial fibrosis, inflammation and oxidative stress and transforming growth factor-β1 (TGF-β1) expression were examined after the mice were sacrificed on Day 7. Activation of Src and its downstream signaling effectors, including extracellular regulated protein kinase 1/2 (ERK1/2), p38 mitogen-activated protein kinase (p38 MAPK) and protein kinase B (AKT), were evaluated. pNaKtide administration markedly attenuated myofibroblast accumulation and extracellular matrix deposition in obstructed kidneys. Also, pNaKtide significantly reduced the increased expression of 8-iso-prostaglandin F2α, TGF-β1, interleukin-6 and monocyte chemoattractant protein-1 (MCP-1), as well as reduced macrophage infiltration, in UUO animals. All these changes were obtained, along with inhibition of Src and its downstream effector activity. Na/K-ATPase-mediated signaling pathways contribute to fibrogenesis and could represent a potential target in the treatment of renal fibrosis.