Shared and Distinct Renal Transcriptome Signatures in 3 Standard Mouse Models of Chronic Kidney Disease.

INTRODUCTION: Several mouse models with diverse disease etiologies are used in preclinical research for chronic kidney disease (CKD). Here, we performed a head-to-head comparison of renal transcriptome signatures in standard mouse models of CKD to assess shared and distinct molecular changes in three mouse models commonly employed in preclinical CKD research and drug discovery. METHODS: All experiments were conducted on male C57BL/6J mice. Mice underwent sham, unilateral ureter obstruction (UUO), or unilateral ischemic-reperfusion injury (uIRI) surgery and were terminated two- and 6-weeks post-surgery, respectively. The adenine-supplemented diet-induced (ADI) model of CKD was established by feeding with adenine diet for 6 weeks and compared to control diet feeding. For all models, endpoints included plasma biochemistry, kidney histology, and RNA sequencing. RESULTS: All models displayed increased macrophage infiltration (F4/80 IHC) and fibrosis (collagen 1a1 IHC). Compared to corresponding controls, all models were characterized by an extensive number of renal differentially expressed genes (≥11,000), with a notable overlap in transcriptomic signatures across models. Gene expression markers of fibrosis, inflammation, and kidney injury supported histological findings. Interestingly, model-specific transcriptome signatures included several genes representing current drug targets for CKD, emphasizing advantages and limitations of the three CKD models in preclinical target and drug discovery. CONCLUSION: The UUO, uIRI, and ADI mouse models of CKD have significant commonalities in their renal global transcriptome profile. Model-specific renal transcriptional signatures should be considered when selecting the specific model in preclinical target and drug discovery.

Numerical analysis of an obstacle motion in the human ureter using the dynamic mesh approach.

Peristalsis is a common motion in various biological systems, especially the upper urinary tract, where it plays a pivotal role in conveying urine from the kidneys to the bladder. Using computational fluid dynamics, this study aims to investigate the effect of various peristaltic parameters on the motion of an obstacle through a two-dimensional ureter. Methodologically, Incompressible Navier-Stokes equations were utilized as the fluid domain's governing equations, and the Dynamic Mesh method (DM) was employed to simulate the peristaltic and obstacle motion. The peristaltic motion was modeled by a sinusoidal contraction wave propagating alongside the ureter at the physiological speed, and the motion of the obstruction through the ureter, which is caused by the fluid forces applied on its surface, was explored using the equation of Newton's second law. Various test cases of different shapes and sizes were supposed as kidney stones to understand the influence of the peristalsis properties on the stone removal process. The results show that the motion of the kidney stone is highly influenced by the gradient pressure force applied to its surface in the fluid domain. Moreover, investigating the effects of the peristaltic physical properties on the obstacle's motion indicates that the stone's motion is dependent on these parameters. Furthermore, this analysis provides insight into the peristaltic motion effects, assisting physicians in developing new medicines to facilitate the kidney stone removal process based on its shape and size.

Antimicrobial and Antiproliferative Coatings for Stents in Veterinary Medicine-State of the Art and Perspectives.

Microbial colonization in veterinary stents poses a significant and concerning issue in veterinary medicine. Over time, these pathogens, particularly bacteria, can colonize the stent surfaces, leading to various complications. Two weeks following the stent insertion procedure, the colonization becomes observable, with the aggressiveness of bacterial growth directly correlating with the duration of stent placement. Such microbial colonization can result in infections and inflammations, compromising the stent's efficacy and, subsequently, the animal patient's overall well-being. Managing and mitigating the impact of these pathogens on veterinary stents is a crucial challenge that veterinarians and researchers are actively addressing to ensure the successful treatment and recovery of their animal patients. In addition, irritation of the tissue in the form of an inserted stent can lead to overgrowth of granulation tissue, leading to the closure of the stent lumen, as is most often the case in the trachea. Such serious complications after stent placement require improvements in the procedures used to date. In this review, antibacterial or antibiofilm strategies for several stents used in veterinary medicine have been discussed based on the current literature and the perspectives have been drawn. Various coating strategies such as coating with hydrogel, antibiotic, or other antimicrobial agents have been reviewed.

Stents in Veterinary Medicine.

Stenting in veterinary medicine has been a rapidly growing method of interventional surgery for several years. This procedure is usually performed in the respiratory and urinary tracts, but there are cases of stenting of blood vessels or gastrointestinal structures. It is based on maintaining the permeability of a given tubular structure, thus allowing the passage of gas or liquid. This procedure is often performed as a first-line treatment in situations where pharmacological agents do not work and as an alternative method, often cheaper than the classically performed ones. There are also cases where stenting is used as a palliative treatment, e.g., to enable defecation in colonic obstruction due to tumour infiltration of the colon wall. Stenting is often a life-saving or comfort-improving procedure for animals, but one should also be aware of possible postoperative complications and be prepared for any adversity. For this reason, this review provides an insight into the current knowledge in veterinary medicine about stenting and the consequences associated with this procedure.

Notch Blockade Specifically in Bone Marrow-Derived FSP-1-Positive Cells Ameliorates Renal Fibrosis.

BACKGROUND: The infiltration of inflammatory cells during a kidney injury stimulates myofibroblast activation leading to kidney fibrosis. Fibroblast-specific protein 1 (FSP-1) positive cells have been reported as either myofibroblasts or monocytes during tissue fibrosis. The functions of FSP-1+ cells that are associated with the development of renal fibrosis and the signaling pathways that regulate FSP-1+ cell activation have not been well defined. METHODS: In mice with unilateral ureteral obstruction (UUO), we characterized FSP-1+ cells and determined the role of the Notch signaling pathway in the activation of bone marrow-derived FSP-1+ cells during kidney fibrosis. RESULTS: In kidneys from mice with UUO, the FSP-1+ cells accumulated significantly in the tubulointerstitial area. By using immunostaining and FSP-1 reporter mice, we found that FSP-1 was co-stained with inflammatory cell markers, but not myofibroblast markers. Results from mice with bone marrow transplantations showed that FSP-1+ cells in obstructed kidneys represent a bone marrow-derived population of inflammatory cells. In cultured FSP-1+ cells, the inhibition of Notch signaling suppressed the activation and cytokine secretion of FSP-1+ cells that were induced by LPS but not by IL-4. The specific KO or blockade of Notch signaling in bone marrow-derived FSP-1+ cells suppressed UUO-induced ECM deposition, the infiltration of FSP-1+ inflammatory cells, and cytokine production. These responses ameliorated myofibroblast accumulation and renal fibrosis in obstructed kidneys. CONCLUSION: Our study reveals that most FSP-1+ cells in obstructed kidneys are activated macrophages that are derived from bone marrow and that Notch signaling activates the production of M1 cytokines in FSP-1+ monocytes/macrophages, which is important for renal inflammation and fibrosis.

Salt-sensitive hypertension after reversal of unilateral ureteral obstruction.

The incidence of ureter obstruction is increasing and patients recovering from this kidney injury often progress to chronic kidney injury. There is evidence that a long-term consequence of recovery from ureter obstruction is an increased risk for salt-sensitive hypertension. A reversal unilateral ureteral obstruction (RUUO) model was used to study long-term kidney injury and salt-sensitive hypertension. In this model, we removed the ureteral obstruction at day 10 in mice. Mice were divided into four groups: (1) normal salt diet, (2) high salt diet, (3) RUUO normal salt diet, and (4) RUUO high salt diet. At day 10, the mice were fed a normal or high salt diet for 4 weeks. Blood pressure was measured, and urine and kidney tissue collected. There was a progressive increase in blood pressure in the RUUO high salt diet group. RUUO high salt group had decreased sodium excretion and glomerular injury. Renal epithelial cell injury was evident in RUUO normal and high salt mice as assessed by neutrophil gelatinase-associated lipocalin (NGAL). Kidney inflammation in the RUUO high salt group involved an increase in F4/80 positive macrophages; however, CD3+ positive T cells were not changed. Importantly, RUUO normal and high salt mice had decreased vascular density. RUUO was also associated with renal fibrosis that was further elevated in RUUO mice fed a high salt diet. Overall, these findings demonstrate long-term renal tubular injury, inflammation, decreased vascular density, and renal fibrosis following reversal of unilateral ureter obstruction that could contribute to impaired sodium excretion and salt-sensitive hypertension.

Noninvasive assessment of renal dynamics and pH in a unilateral ureter obstruction model using DCE MR-CEST urography.

PURPOSE: To assess the potential of DCE MR CEST urography for assessing renal function in mice with unilateral ureter obstruction (UUO) by simultaneous pH and renal uptake/clearance measurements following injection of iopamidol. METHODS: The right ureter of nine mice was obstructed via suture ligation. The animals were imaged at day 1, 2, and 3 post-obstruction on an 11.7T MRI scanner. Ninety-six sets of saturated CEST images at 4.3 and 5.5 ppm were collected. Renal pH values were obtained by calculating the signal ratio for these two frequencies and using a pH calibration curve. Renal time activity curves were measured as a percentage change in the post-injection CEST signal at 4.3 ppm relative to the average pre-injection signal. RESULTS: For the healthy mice, the time activity curves of both kidneys were nearly identical and displayed rapid excretion of contrast. For the UUO mice, the dynamic CEST curves for the obstructed kidneys displayed prolonged time to peak (TTP) values and delayed contrast excretion compared with the contralateral (CL) kidneys. Renal pH maps of the healthy animals showed similar acidic values for both kidneys (pH 6.65 ± 0.04 vs 6.67 ± 0.02), whereas in the obstructed kidneys there was a significant increase in pH values compared with the CL kidneys (pH 6.67 ± 0.08 vs 6.79 ± 0.11 in CL and UUO kidneys, respectively). CONCLUSION: Our findings indicate that DCE-MR-CEST urography can detect changes in renal uptake/excretion and pH homeostasis and distinguish between obstructed and unobstructed kidney as early as 1 day after UUO.

Cyclo(Val-Pro) and Cyclo(Leu-Hydroxy-Pro) from Pseudomonas sp. (ABS-36) alleviates acute and chronic renal injury under in vitro and in vivo models (Ischemic reperfusion and unilateral ureter obstruction).

The study aimed to identify small molecules having potentiality in alleviating renal injury. Two natural compounds cyclo(Val-Pro) (1) and cyclo(Leu-Hydroxy-Pro) (2) were first evaluated under acute renal injury model of ischemic reperfusion at different doses of 25, 50 and 75 mg/kg body weight. Further, the compounds were subjected to antimycin A-induced ischemic in vitro study (NRK-52E cell lines). Both the compounds significantly decreased plasma IL-1ß levels (P < 0.05). Also, the mRNA expression levels of inflammatory markers (TNF-α, IL-6 and IL-1ß) and renal injury markers (KIM-1, NGAL, α-GST and π-GST) in the renal tissues were significantly alleviated (P < 0.01) along with the improvement in histological damage and control over neutrophil infiltration as a result of ischemic reperfusion. The in vitro study revealed the protective effect against antimycin A-induced cytotoxicity (P < 0.05) and antiapoptotic effect acting through the regulation of Bax, caspase 3 (pro and cleaved) and BCL2 with reduction in Annexin+PI+ cells. Further, the compound cyclo(Val-Pro) (1) was evaluated (50 mg/kg body weight dose) in chronic unilateral ureter obstruction model of renal injury in mice and TGF-ß-induced in vitro fibrotic model (NRK-49F cell lines). Cyclo(Val-Pro) (1) significantly reduced the expression levels of fibrotic markers (collagen-1, α-SMA and TGF-ß) and showed marked alleviation of renal fibrosis (sirius red staining). Also, the proliferation of TGF-ß-induced NRK-49F cells was significantly reduced along with decreased levels of collagen-1 and α-SMA in immunohistochemistry studies. In conclusion, the compounds significantly abrogated ischemic injury by inhibiting renal inflammation and tubular epithelial apoptosis. Further, cyclo (Val-Pro) (1) exhibited significant anti-fibrotic activity through the inhibition of fibroblast activation and proliferation. Thus, these proline-based cyclic dipeptides are recommended as drug leads for treating renal injury.

Evaluation of pheniramine maleate and zofenopril in reducing renal damage induced by unilateral ureter obstruction. An experimental study.

INTRODUCTION: Obstruction of the ureter may occur due to congenital, iatrogenic or other reasons. This can cause hydronephrosis in the early stage and can lead to cellular inflammation, necrosis and atrophy in the kidney tissue. The aim of this paper is to evaluate the protective effect of pheniramine maleate (PM) and zofenopril on renal damage caused by hydronephrosis due to unilateral partial ureter obstruction. MATERIAL AND METHODS: Twenty-four female Sprague Dawley rats were divided into 4 groups. Group 1: sham group, group 2: partial unilateral ureteral obstruction (PUUO) group, group 3: PUUO + PM group, group 4: PUUO + zofenopril group. Paraoxonase (PON), total antioxidant status (TAS) and total oxidant status (TOS) of tissue and blood samples were measured and calculated. Tissue samples were evaluated histopathologically. RESULTS: An increase in tissue TAS and a decrease in tissue TOS and OSI levels were detected in groups 3 and 4 compared to group 2 (both: p < 0.01). Tissue PON levels showed an increase in groups 3 and 4 compared to groups 1 and 2 (both: p < 0.01). Histopathological evaluation showed a decrease in interstitial inflammation and congestion in groups 3 and 4 compared to the control group (p < 0.001). The decrease was observed to be more significant in group 4 compared to group 3 (p < 0.01). CONCLUSIONS: In our experimental study, we observed that PM and zofenopril reduce the oxidation and tissue damage caused by unilateral partial obstruction.

Renal tubular dilation and fibrosis after unilateral ureter obstruction revealed by relaxometry and spin-lock exchange MRI.

We evaluated the use of quantitative MRI relaxometry, including the dispersion of spin-lock relaxation with different locking fields, for detecting and assessing tubular dilation and fibrosis in a mouse model of unilateral ureter obstruction (UUO). C57BL/6 J and BALB/c mice that exhibit different levels of tubular dilation and renal fibrosis after UUO were subjected to MR imaging at 7 T. Mice were imaged before UUO surgery, and at 5, 10 and 15 days after surgery. We acquired maps of relaxation rates and fit the dispersion of spin-lock relaxation rates R1ρ at different locking fields (frequencies) to a model of exchanging water pools, and assessed the sensitivity of the derived quantities for detecting tubular dilation and fibrosis in kidney. Histological scores for tubular dilation and fibrosis, based on luminal space and positive fibrotic areas in sections, were obtained for comparison. Histology detected extensive tubular dilation and mild to moderate fibrosis in the UUO kidneys, in which enlargement of luminal space, deposition of collagen, and reductions in capillary density were observed in the cortex and outer stripe of the outer medulla. Relaxation rates R1 , R2 and R1ρ clearly decreased in these regions of UUO kidneys longitudinally. While R1 showed the highest detectability to tubular dilation and overall changes in UUO kidneys, Sρ , a parameter derived from R1ρ dispersion data, showed the highest correlation with renal fibrosis in UUO. While relaxation parameters are sensitive to tubular dilation in UUO kidneys, Sρ depends primarily on the average exchange rate between water and other chemically shifted resonances such as hydroxyls and amides, and provides additional specific information for evaluating fibrosis in kidney disease.

Evaluation of Renal Function in Obstructed Ureter Model Using 99mTc-DMSA.

BACKGROUND/AIM: Urinary obstruction is a condition of impaired urinary drainage, which may result in progressive renal deterioration. This study applied 99mTc-labeled dimercaptosuccinic acid (99mTc-DMSA) renal scintigraphy to a rabbit model of right ureter obstruction and evaluated its utility in studying obstructive renal diseases. MATERIALS AND METHODS: Complete unilateral ureter obstruction in rabbits was generated by complete ligation of the right ureter. Renal function was investigated during a 4-week post-obstruction period by obtaining planar images of 99mTc-DMSA activity following ear vein injection. Renal blood perfusion was evaluated by non-invasive scintigraphy in conjunction with parallel histological and hematological examinations. RESULTS: Renal perfusion was remarkably and rapidly reduced in the ureter-obstructed kidneys. During the experimental period, the size of left kidney appeared normal in the scintigraphic images, but the ureter-obstructed right kidney progressively became larger. Histopathological examination showed flattening and atrophy of tubules, enlargement of interstitial areas, accumulation of extracellular martices and infiltration of inflammatory cells in the obstreucted kidney. CONCLUSION: 99mTc-DMSA scintigraphy is a sensitive, non-invasive method to assess renal function in unilateral kidney diseases.

Endothelial Cell-Specific Molecule 1 Promotes Endothelial to Mesenchymal Transition in Renal Fibrosis.

The endothelial-to-mesenchymal transition (EndoMT) is involved in the complex pathogenesis of renal fibrosis. The soluble proteoglycan endothelial cell-specific molecule 1 (ESM1) is significantly upregulated in many tumor cells and cirrhosis-related disease. The role of ESM1 in renal fibrosis is unknown. This study investigates the role of ESM1 in renal fibrosis, using an in vivo unilateral ureteral obstruction (UUO) mouse model of renal fibrosis and in vitro mouse kidney MES 13 cells overexpressing ESM1. We observed that ESM1 overexpression significantly increased the motility and migration of MES 13 cells, independent of cell viability. In ESM1-overexpressing MES 13 cells, we also observed elevated expression of mesenchymal markers (N-cadherin, vimentin, matrix metallopeptidase 9 (MMP9)) and the fibrosis marker α-smooth muscle actin (α-SMA) and decreased expression of the endothelial marker vascular endothelial cadherin (VE-cadherin) and CD31. In a mouse model of fibrosis induced by unilateral ureter obstruction, we observed time-dependent increases in ESM1, α-SMA, and vimentin expression and renal interstitial collagen fibers in kidney tissue samples. These results suggest that ESM1 may serve as an EndoMT marker of renal fibrosis progression.

Congenital bilateral absence of the vas deferens (CBAVD) with bilaterally present seminal vesicles.

Congenital bilateral absence of the vas deferens (CBAVD) is a rare obstructive anomaly contributing to male factor infertility. Various congenital anomalies associated with CBAVD involve the seminal vesicles and epididymis. Physical examinations are often not reliable. However, transrectal ultrasonography (TRUS) can distinguish seminal vesicle and epididymal anomalies. In this clinical report, a rare case of CBAVD without seminal vesical anomalies is presented. PE and TRUS revealed no remarkable findings. The patient underwent vaso-epididymal anastomosis for the seminal tract obstruction and was accidentally diagnosed with CBAVD. Although ultrasonography is a reliable approach, surgical methods are critical for the diagnosis of CBAVD.

Cyclic helix B peptide ameliorates renal tubulointerstitial fibrosis induced by unilateral ureter obstruction via inhibiting NLRP3 pathway.

BACKGROUND: Renal fibrosis is the inevitable outcome of all progressive chronic kidney diseases (CKD) and leads to a gradual loss of renal function. We previously reported cyclic helix B peptide (CHBP), a novel synthesized peptide derived from erythropoietin, had shown effective renoprotection. In this study, we investigated the anti-fibrotic and renoprotective effect of CHBP in a murine renal tubulointerstitial fibrosis model induced by unilateral ureter obstruction (UUO). METHODS: Mice were subjected to the UUO model and CHBP was given intraperitoneally. To assess the therapeutic effects of CHBP, pathological injury, deposition of extracellular matrix (ECM) and the progression of epithelial-mesenchymal transition (EMT) were examined in vivo. The anti-fibrotic effects of CHBP was validated in vitro using TCMK-1 cells treated with TGF-ß1. Involvement of the NLRP3 pathway was demonstrated both in vivo and in vitro. RESULTS: CHBP significantly ameliorated renal tubulointerstitial injury and fibrosis in terms of ECM deposition. The EMT process was also alleviated after CHBP treatment. Similar therapeutic effects of CHBP were also observed in vitro in TGF-ß1 treated tubular epithelial cells (TECs). NLRP3/caspase-1/IL-1ß pathway was involved and activated upon injury, both in vivo and in vitro. While the activation of the NLRP3 pathway was found to be in negative correlation with CHBP treatment. CHBP could suppress the activation of NLRP3 and its downstream inflammatory mediators even with addition of extracellular ATP, a direct activator of the NLRP3 inflammasome. CONCLUSIONS: Our results suggest that CHBP could effectively protect the kidney from renal tubulointerstitial fibrosis in the UUO model via counteracting the NLRP3/caspase-1/IL-1ß pathway.

Upregulation of Cortical Renin and Downregulation of Medullary (Pro)Renin Receptor in Unilateral Ureteral Obstruction.

Chronic kidney disease (CKD) is characterized by renal dysfunction, which is a common feature of other major diseases, such as hypertension and diabetes. Unilateral ureteral obstruction (UUO) has been used as a model of CKD in experimental animals and consists of total obstruction of one kidney ureter. The UUO decreases renal blood flow, which promotes the synthesis of renin in the juxtaglomerular apparatus, the first step in renin-angiotensin system (RAS) cascade. RAS induces inflammation and remodeling, along with reduced renal function. However, it remains unknown whether intrarenal RAS (iRAS) is activated in early stages of CKD. Our objective was to characterize different iRAS components in the renal cortex and in the medulla in an early phase of UUO. Male C57BL/6 mice (8-12 weeks old) were subjected to UUO in the left kidney, or to sham surgery, and were euthanized after 7 days (n = 5/group). Renal function, renal inflammatory/remodeling processes, and iRAS expression were evaluated. UUO increased plasma creatinine, right renal hypertrophy (9.08 ± 0.31, P < 0.05 vs. Sham), and tubular dilatation in the left kidney cortex (42.42 ± 8.19µm, P < 0.05 vs. Sham). This correlated with the increased mRNA of IL-1ß (1.73 ± 0.14, P < 0.01 vs. Sham, a pro-inflammatory cytokine) and TGF-ß1 (1.76 ± 0.10, P < 0.001 vs. Sham, a pro-fibrotic marker). In the renal cortex of the left kidney, UUO increased the mRNA and protein levels of renin (in 35% and 28%, respectively, P < 0.05 vs. Sham). UUO decreased mRNA and protein levels for the (pro)renin receptor in the renal medulla (0.67 ± 0.036 and 0.88 ± 0.028, respectively, P < 0.05 vs. Sham). Our results suggest that modulation of iRAS components depends on renal localization and occurs in parallel with remodeling and pro-inflammatory/pro-fibrotic mechanisms.

The Effect of Tadalafil on Renal Fibrosis Induced by Ureteral Obstruction / Efecto del Tadalafil en la Fibrosis Renal Inducida por Obstrucción Uretral

ABSTRACT Objective: It has been reported that phosphodiesterase-5 (PDE-5) inhibitors improve kidney function during acute and chronic renal failure. This study aimed to determine the possible therapeutic effects of tadalafil, a specific PDE-5 inhibitor, on renal fibrosis induced by unilateral ureteral obstruction (UUO). Methods: Male Sprague-Dawley rats were used and randomly divided into three groups (n = 6) as sham-operated, UUO and tadalafil-treated (10 mg/72 hours, ig) UUO (UUO+T) groups. Unilateral ureteral obstruction was induced by complete ligation of the left ureter and 14 days after surgery creatinine clearance, urinary cyclic guanosine monophosphate (cGMP), renal alpha-smooth muscle actin (α-sma) and transforming growth factor βeta (TGF-β) levels, as well as histologic changes, were observed in all the animals. Results: Unilateral ureteral obstruction-induced renal fibrosis was confirmed by increased α-sma level, collagen deposition, tubular dilation, inflammatory cell infiltration and necrosis. An increased renal TGF-β level and decreased urinary cGMP level was also observed in obstructed animals in addition to reduced creatinine clearance. Tadalafil treatment, which restored the animals 'urinary cGMP level, significantly attenuated the fibrotic changes and TGF-β increase in their kidneys. Conclusion: This study suggests that tadalafil treatment ameliorates renal fibrosis by reducing TGF-β expression and may have important clinical relevance since tadalafil is currently used clinically to treat erectile dysfunction and pulmonary hypertension.

RESUMEN Objetivo: Se ha reportado que los inhibidores de la fosfodiesterasa-5 (PDE-5) mejoran las funciones renales durante la insuficiencia renal aguda y crónica. Este estudio tuvo por objetivo determinar los posibles efectos terapéuticos del tadalafil - un inhibidor específico de la PDE-5 - sobre la fibrosis renal inducida por una obstrucción ureteral unilateral (OUU). Métodos: Se utilizaron ratas machos Sprague-Dawley, divididas de manera aleatoria en tres grupos (n = 6): operación simulada, OUU y tratamiento con tadalafil (10 mg/72 horas, IG), y OUU (OUU+T). La obstrucción uretral unilateral fue inducida por una ligadura completa del uréter izquierdo y 14 días después de la cirugía, se observaron niveles de monofosfato de guanosina cíclico (GMP) urinario, alfa-actina de músculo liso (α-SMA), y factor de crecimiento transformante βeta (FCT-β), así como cambios histológicos en todos los animales. Resultados: La fibrosis renal inducida por obstrucción uretral unilateral fue confirmada por un aumento del nivel de α-SMA, deposición de colágeno, dilatación tubular, infiltración de células inflamatorias y necrosis. También se observó un aumento del nivel de FCT-β renal y una disminución del nivel de GMP urinario en los animales con obstrucción, además de una reducción del aclaramiento de la creatinina. El tratamiento con tadalafil, que restauró el nivel de GMP urinario de los animales, atenuó significativamente los cambios fibróticos y el aumento de FCT-β en los riñones. Conclusión: Este estudio sugiere que el tratamiento con tadalafil mejora la fibrosis renal al reducir la expresión de FCT-β y puede tener una importante relevancia clínica por cuanto el tadalafil se usa hoy día clínicamente para tratar la disfunción eréctil y la hipertensión pulmonar.

Protease-activated receptor-1 contributes to renal injury and interstitial fibrosis during chronic obstructive nephropathy.

End-stage renal disease, the final stage of all chronic kidney disorders, is associated with renal fibrosis and inevitably leads to renal failure and death. Transition of tubular epithelial cells (TECs) into mesenchymal fibroblasts constitutes a proposed mechanism underlying the progression of renal fibrosis and here we assessed whether protease-activated receptor (PAR)-1, which recently emerged as an inducer of epithelial-to-mesenchymal transition (EMT), aggravates renal fibrosis. We show that PAR-1 activation on TECs reduces the expression of epithelial markers and simultaneously induces mesenchymal marker expression reminiscent of EMT. We next show that kidney damage was reduced in PAR-1-deficient mice during unilateral ureter obstruction (UUO) and that PAR-1-deficient mice develop a diminished fibrotic response. Importantly, however, we did hardly observe any signs of mesenchymal transition in both wild-type and PAR-1-deficient mice suggesting that diminished fibrosis in PAR-1-deficient mice is not due to reduced EMT. Instead, the accumulation of macrophages and fibroblasts was significantly reduced in PAR-1-deficient animals which were accompanied by diminished production of MCP-1 and TGF-ß. Overall, we thus show that PAR-1 drives EMT of TECs in vitro and aggravates UUO-induced renal fibrosis although this is likely due to PAR-1-dependent pro-fibrotic cytokine production rather than EMT.

Effect of erythropoietin on the expression of aquaporin 2-3 after the release of unilateral ureter obstruction in young rats / 中华实用儿科临床杂志

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).There was no significant difference between CUUO-R + EPO group and Sham group(P ＞ 0.05).The immunohistochemistry showed that the expressions of AQP2 and AQP3 in collecting 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 expression of AQP2 and AQP3 as well as renal function at the early period after the release of ureteral obstruction in young rats.

Effect of erythropoietin on the expression of aquaporin 2-3 after the release of unilateral ureter obstruction in young rats / 中华实用儿科临床杂志

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). There was no significant difference between CUUO-R+ EPO group and Sham group(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.

Effect of erythropoietin on the eXpression and function of renal aquaporin－1 after release of bilateral ureter obstruction in young rats / 中华实用儿科临床杂志

Objective To investigate the effect of erythropoietin(EDO)on the expression and function of aqua_porin_1( AQD _1)in the kidney of young male SD rats after release of bilateral ureter obstruction( BUO _ R). Methods Porty_eight young SD rats were randomly divided into bilateral ureteral complete obstruction(BUO)group (n﹦6),BUO_R group(n﹦12),BUO_R﹢EDO group( n﹦12)and Sham group( n﹦18). The BUO model was built through bilateral ureteral ligation. BUO group were killed after 24 h,and BUO_R group and BUO_R﹢EDO group were relieved after obstruction of 24 h. EDO(500 U∕kg)was given to BUO_R﹢EDO rats at 1 h after release of BUO,and then repeated 1 d,3 d and 5 d thereafter and the same volume of 9 g∕L saline was simultaneously given to BUO_R rats. The Sham group was prepared in parallel by laparotomy and free dissection of bilateral ureters but not ligated,both side kidneys and blood samples were collected on 3 d and 7 d(24 h,3 d,7 d for Sham group)after release of BUO. The u_rine samples were collected by using metabolic cage before death. The plasma osmotic pressure,creatinine(Cr)and u_rea nitrogen(BUN)in the plasma of young rats were detected. The expression of AQD_1 protein in all groups of kidney tissues was detected by adopting immunohistochemistry and Western blot. Results On day 3 after release of BUO,24 h water intake and urine volume of BUO_R﹢EDO group were higher than those of Sham group,but lower than those of BUO group(P〈0. 05),the urine osmotic pressure of BUO_R﹢EDO group was higher than that of BUO group,but lower than that of Sham group(P〈0. 05),while plasma osmotic pressure,Cr and BUN of BUO_R﹢EDO group were higher than those of Sham group,but lower than those of BUO group(P〈0. 05),and they were all of lower than BUO group( P 〈0. 05). On day 7 after release of BUO,there was no obvious change in Sham group,and the indexes of BUO_R group and BUO_R﹢EDO group gradually recovered,but they still did not reach the normal level(P〈0. 05). The difference between BUO_R group and BUO_R﹢EDO group was statistically significant(P〈0. 05). The immuno_histochemical results showed that the expression of AQD_1 in collecting duct in BUO group was significantly down_regulated compared with that in Sham group,whereas it was slightly weaker in BUO_R group and BUO_R﹢EDO group than that of Sham group(P〈0. 05). Compared with 3 days after release of BUO,the staining intensity of BUO_R﹢EDO group and BUO_R group was enhanced,but still lower than that of the Sham group. These results were further confirmed by adopting Western blot,and BUO group was also the lowest of the four groups,and BUO_R﹢EDO group was higher than that of BUO group,but lower than that of Sham group( P〈0. 05). Conclusion EDO can promote not only the recovery of AQD_1 protein expression but also the recovery of renal function in young BUO_R rats.