Peroxisome Proliferator-activated Receptor-γ Agonist Pioglitazone Fails to Attenuate Renal Fibrosis Caused by Unilateral Ureteral Obstruction in Mice

Renal tubulointerstitial fibrosis is the common ending of progressive renal disease. It is worth developing new ways to stop the progress of renal fibrosis. Peroxisome proliferator-activated receptor-γ（PPARγ） agonists have been studied to treat diabetic nephropathy, cisplatin-induced acute renal injury, ischemia reperfusion injury and adriamycin nephropathy. In this study, unilateral ureteral obstruction（UUO） was used to establish a different renal fibrosis model. PPARγ agonist pioglitazone was administrated by oral gavage and saline was used as control. At 7th and 14 th day after the operation, mice were sacrificed for fibrosis test and T lymphocytes subsets test. Unexpectedly, through MASSON staining, immunohistochemistry for α-SMA, and Western blotting for α-SMA and PDGFR-β, we found that pioglitazone failed to attenuate renal fibrosis in UUO mice. However, flow cytometry showed that pioglitazone down-regulated Th1 cells, and up-regulated Th2 cells, Th17 cells and Treg cells. But the Th17/Treg ratio had no significant change by pioglitazone. Real-time PCR results showed that TGF-β and MCP-1 had no significant changes, at the same time, CD4＋ T cells associated cytokines were partially regulated by pioglitazone pretreatment. Taken together, pioglitazone failed to suppress renal fibrosis progression caused by UUO.

Expression of BMP-7 and its receptors in renal tubolo-interstitial fibrosis induced with unilateral ureteral obstruction in rats

Objective:To study the changes of the expression of bone morphogenetic protein-7(BMP-7) and its receptors(BMPR-Ⅱ,ALK2,ALK3 and ALK6) in the renal tubulointerstitial fibrosis induced with unilateral ureteral obstruction in rats. Methods: Sixty Wistar male rats were divided randomly into the normal control,sham-operation and unilateral ureteral obstruction(UUO) groups and the rats were killed on the 1st,3rd,7th and 14th postoperative days respectively.The mRNA level of BMP-7,BMPR-Ⅱ,ALK2,ALK3 and ALK6 was determined with RT-PCR.The site and level of protein expression of BMP-7 were observed with immunohistochemical staining. Results: The mRNA level of BMP-7,BMPR-Ⅱ,ALK2 and ALK3 was significantly decreased in the rats of UUO group than in those of the sham-operation group but the mRNA level of ALK6 showed no obvious changes in all the rats.Immunohistochemical staining revealed that the protein of BMP-7 was mainly expressed in the renal tubules and interstitial tissue of the kidneys in normal rats but it was decreased gradually along with the unilateral ureteral obstruction. Conclusion: It is found that the loss of BMP-7 and its receptors including BMPR-Ⅱ,ALK2 and ALK3 occurs in the early phase of renal tubulointerstitial fibrosis before the appearance of other pathological changes in the kidney and may play an important role in the occurrence and progress of renal tubulointerstitial fibrosis.

Role of BMP-7 and TGF-β_1 expression in renal tubulo-interstitial lesion of Wistar rats induced by unilateral ureteral obstruction

Objective: To explore the role of bone morphorgenetic protein-7 （BMP-7） in the renal tubulo-interstitial lesions induced by unilateral ureteral obstruction （UUO）. Methods: Sixty Wistar rats were equally and randomly divided into normal control, sham operation and UUO groups, and respectively sacrificed on the 1st, 3rd, 7th, 14th day after the time of UUO operation. The mRNA levels of BMP-7 and TGF-β1 in the renal tissues were examined by RT-PCR. The expression sites and levels of BMP-7 and TGF-β1 proteins were detected by immunohistochemistry staining. Results:Compared to control groups, the level of BMP-7 mRNA was significantly decreased, but that of TGF-β1 mRNA was significantly increased in UUO rats. Immunohistochemistry staining indicated that BMP-7 mainly expressed in the renal tubules and interstitum, rarely in the glomeruli. In UUO rats, the expression of BMP-7 protein was decreased, but that of TGF-β1 was increased in an obstruction dependent manner. Conclusion:The down- regulation of BMP-7 is observed in the early phase of fibrotic process of the renal interstitium, suggesting it may be involved in the formation and development of the tubulo-interstitial lesions.

Huoxue Jiedu Huayu recipe(活血解毒化瘀方)inhibits macrophage-secreted vascular endothelial growth factor-a on angiogenesis and alleviates renal fibrosis in the contralateral kidneys of unilateral ureteral obstruction rats

OBJECTIVE:To elucidate the mechanism by which Huoxue Jiedu Huayu recipe(活血解毒化瘀方,HJHR)regulates angiogenesis in the contralateral kidney of unilateral ureteral obstruction(UUO)rats and the mechanism by which it reduces of renal fibrosis.METHODS:Male Wistar rats were randomly divided into 4 groups:the sham group,UUO group(180 d of left ureter ligation),UUO plus eplerenone(EPL)group,and UUO plus HJHR group.After 180 d of oral drug administration,blood and contralateral kidneys were collected for analysis.Angiogenesis-and fibrosis-related indexes were detected.RESULTS:HJHR and EPL improved structural damage and renal interstitial fibrosis in the contralateral kidney and reduced the protein expression levels ofα-smooth muscle actin(α-SMA),vimentin and collagen I.Moreover,these treatments could reduce the expression of vascular endothelial growth factor-A(VEGFA)by inhibiting the infiltration of macrophages.Furthermore,HJHR and EPL significantly reduced the expression of CD34 and CD105 by downregulating VEGFA production,which inhibited angiogenesis.Finally,the coexpressions of CD34,CD105 andα-SMA were decreased in the HJHR and EPL groups,indicating that endothelial-to-mesenchymal transition was inhibited.CONCLUSIONS:These findings confirm that HJHR alleviates contralateral renal fibrosis by inhibiting VEGFAinduced angiogenesis,encourage the use of HJHR against renal interstitial fibrosis and provide a theoretical basis for the clinical management of patients with CKD.

Ginsenoside Rb1,a Panoxadiol Saponin against Oxidative Damage and Renal Interstitial Fibrosis in Rats with Unilateral Ureteral Obstruction

Objective:To investigate the possible protective effect and mechanism of ginsenoside Rb1 against oxidative damage and renal interstitial fibrosis on rats with unilateral ureteral obstruction(UUO). Methods:In total,80 male rats were randomly divided into 4 groups,20 in each group:the sham operated group (SOR),UUO group,UUO with ginsenoside Rb1 treatment group(treated with intraperitoneal injection of 50 mg/ kg daily) and UUO with Losartan treatment group(as the positive control,treated with 20 mg/kg by gastr...

Arterially transplanted mesenchymal stem cells in a mouse reversible unilateral ureteral obstruction model： in vivo bioluminescence imaging and effects on renal fibrosis

Background Chronic kidney disease （CDK） is a worldwide health problem, but there is currently no effective treatment that can completely cure this disease. Recently, studies with mesenchymal stem cells （MSCs） on treating various renal diseases have shown breakthroughs. This study is to observe the homing features of MSCs transplanted via kidney artery and effects on renal fibrosis in a reversible unilateral ureteral obstruction （R-UUO） model. Methods Thirty-six Balb/c mice were divided into UUO group, UUO-MSC group, and sham group randomly, with 12 mice in each group. The MSCs had been infected by a lentiviral vector to express stably the luciferase reporter gene and green fluorescence protein genes （Luc-GFP-MSC）. Homing of MSCs was tracked using in vivo imaging system （IVIS） 1, 3, 14, and 28 days after transplantation. Imaging results were verified by detecting GFP expression in frozen section under a fluorescence microscope. E-cadherin, α-SMA, TGF-β1, and TNF-α mRNA expression in all groups at 1 and 4 weeks after transplantation were analyzed by quantitative PCR. Results Transplanted Luc-GFP-MSCs showed increased Luciferase expression 3 days after transplantation. The expression decreased from 7 days, weakened thereafter and could not be detected 14 days after transplantation. Quantitative PCR results showed that all gene expressions in UUO group and UUO-MSC group at 1 week had no statistical difference, while at 4 weeks, except TGF-β expression （P〉0.05）, the expression of E-cadherin, α-SMA, and TNF-α in the above two groups have statistical difference （P〈0.01）. Conclusion IVIS enables fast, noninvasive, and intuitive tracking of MSC homing in vivo. MSCs can be taken home to kidney tissues of the diseased side in R-UUO model, and renal interstitial fibrosis can be improved as well.

Trabecular bone deterioration at the greater trochanter ol mice with unilateral obstructive nephropathy

Our previous study showed the early molecular responses of bone in response to obstructive nephropathy in a unilateral ureteral obstruction （UUO） mouse model. Here, we addressed the changes in trabecular bone properties at greater trochanter, the proximal and the distal metaphysis of femur in UUO mice. The male mice were subjected to UUO （n= 10） or sham operation （n= 10）. All mice were killed on day 7 after the surgical operation. The micro-computed tomography （micro-CT） analysis for different femoral trabecular bone sites demonstrated pathological alterations of trabecular bone mass and micro-networks at greater trochanter as shown by decreases in bone mineral density/bone volume （P〈O.05） and trabecular number （P〈O.05） and increases in trabecular separation （P〈O.01） and bone surface/bone volume （P〈O.05） in UUO mice. The present study demonstrates that UUO-induced unilateral obstructivenephropathy has markedly detrimental effects on the trabecular trochanter of the femur.

CTRP1 Attenuates UUO-induced Renal Fibrosis via AMPK/NOX4 Pathway in Mice

Clq/TNF-related protein 1(CTRP1),a conserved protein of the Clq family,plays a key role in cardiovascular and metabolic diseases.However,the role of CTRP1 in renal injury is unclear.The purpose of this study is to explore the role of CTRP1 in unilateral ureteral obstruction(UUO)-induced renal fibrosis and to elucidate the underlying mechanism.Using gene delivery system,CTRP1 was overexpressed in the kidney,then the mice were operated to induce UUO model after adenovirus transfection.It was found that the expression of CTRP1 in the renal tissue was decreased in mice after UUO.CTRP1 overexpression decreased the kidney function and kidney weight index.Moreover,CTRP1 reduced oxidative stress and renal collagen deposition in vivo.As expected,we found that CTRP1 activated AMP-activated kinase(AMPK)and decreased NOX4 expression,while silencing AMPKal abolished the protective effects of CTRP1 overexpression in mice after UUO.In conclusion,CTRP1 may protect against UUO-induced renal injury via AMPK/NOX4 signaling.Our results indicate that CTRP1 exhibits potential effects to treat renal fibrosis caused by UUO.

Role of Protease Activated Receptor-2 Expression in Renal Interstitial Fibrosis Model in Mice

Summary： The role of protease activated receptor-2 （PAR-2） in the renal tubulointerstitial lesion induced by unilateral ureteral obstruction （UUO） was explored. Mice were sacrificed on the day 1, 3, 5, 7, 10, 14 and 21 after UUO. The expression of PAR-2 mRNA and protein and a-smooth muscle actin （α-SMA） protein in tubuloin,terstitium was detected by RT-PCR and immunohistochemistry at each time point, respedtively. The results showed that the PAR-2 expression in renal tubulointerstitium was increased progressively starting from 24 h to the day 14 post-ligation, and it was significantly associated with the relative volume of interstitium and the positive area of α-SMA. PAR-2 was mainly expressed in renal tubule epithelial cells, especially in proximal tubular cells. It also located in renal capillary ansa, interstitial infiltrate cells and fibroblasts. It was concluded that PAR-2 was active in interstitial and tubular cells in the early phase of fibrotic process and played an important role in mediating the tubulointerstitial lesion after UUO.

MHC class Ⅱ in renal tubules plays an essential role in renal fibrosis

Immunomodulation has been considered a potential therapeutic approach for chronic kidney disease(CKD).Although it has been previously reported that CD4+T cells contribute to the development of renal fibrosis after UUO,the role of MHC class Ⅱ(MHCII)in UUO-induced renal fibrosis remains largely uncharacterized.The present study reports that the expressions of MHCII molecules in renal cortical tubules are upregulated in a mouse unilateral ureter obstruction(UUO)model.Global or renal tubule-specific ablation of MHCII significantly alleviates renal fibrosis following UUO.Additionally,renal expression of profibrotic genes showcased consistent reduction in both MHCII gene deficient mouse lines.These results demonstrate that renal tubular MHCII plays an important role in pathogenesis of renal fibrosis.

The effects of Kangxianling on renal fibrosis as assessed with a customized gene chip

OBJECTIVE:To determine the mechanisms by which Kangxianling(KXL) treats renal interstitial fibrosis using a customized gene chip.METHODS:Twelve out of 18 specific pathogen-free sprague dawley(SPF SD) rats underwent a unilateral ureteral occlusion.These rats were then randomly assigned into either the model unilateral ureteral obstruction(UUO) or Kangxianling(KXL) group.The other six rats were assigned to the sham-operated group.The UUO and sham-operated groups were given normal saline via intragastric administration,whereas the KXL group was given KXL via intragastric administration.All rats were sacrificed for renal tissue collection(i.e.left nephridial tissue),and the detection of genetic changes with the customized chip.RESULTS:Compared to the sham-operated group,transforming growth factor-β1(TGF-β1),Smad2,and Smad3 genes were significantly up-regulated in the UUO group,with >1.5-fold rise(P<0.01).The Smad7 gene was significantly reduced in the UUO versus sham-operated group,with a down-regulation of >1.5-fold(P<0.01).In the KXL group,TGF-β1,Smad2,and Smad3 genes were significantly reduced compared to the UUO group,with a down-regulation of >1.5-fold(P<0.01),whereas the Smad7 gene was significantly increased compared to the UUO group,with an up-regulation of >1.5-fold(P<0.01).CONCLUSION:It was found that KXL can significantly reduce the gene levels of TGF-β1,Smad2,and Smad3.Immunohistochemistry findings also revealed significantly lower TGF-β1/Smads-mediated gene transcription activity.These findings suggest that KXL may negatively regulate the TGF-β1/Smads signal pathway to inhibit the occurrence of renal fibrosis.