Renal Interstitial Fibrosis In Rats Research Articles

Attenuating Renal Interstitial Fibrosis by Shenqi Pill viaReducing Inflammation Response Regulated by NF-κBPathway In Vitro and In Vivo.

One of the most significant clinical features of chronic kidney disease is renal interstitial fibrosis (RIF). This study aimed to investigate the role and mechanism of Shenqi Pill (SQP) on RIF. RIF model was established by conducting unilateral ureteral obstruction (UUO) surgery on rat or stimulating human kidney-2 (HK-2) cell with transforming growth factor β1 (TGFβ1). After modeling, the rats in the SQP low dose group (SQP-L), SQP middle dose group (SQP-M) and SQP high dose group (SQP-H) were treated with SQP at 1.5, 3 or 6 g/kg/d, and the cells in the TGFβ1+SQP-L/M/H were treated with 2.5%, 5%, 10% SQP-containing serum. In in vivo assays, serum creatinine (SCr) and blood urea nitrogen (BUN) content were measured, kidney histopathology was evaluated., and α-smooth muscle actin (α-SMA) expression was detected by immunohistochemistry. Interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) content, inhibitor of kappa B alpha (IKBα) and P65 phosphorylation were assessed. Meanwhile, cell viability, inflammatory cytokines content, α-SMA expression, IKBα and P65 phosphorylation were detected in vitro experiment. Results. SQP exhibited reno-protective effect by decreasing SCr and BUN content, improving renal interstitial damage, blunting fibronectin (FN) and α-SMA expression in RIF rats. Similarly, after the treatment with SQP-containing serum, viability and α-SMA expression were remarkably decreased in TGFβ1-stimulated HK-2 cell. Furthermore, SQP markedly down-regulated IL-1β, IL-6, and TNF-α content, IKBα and RelA (P65) phosphorylation both in vivo and in vitro. Conclusion. SQP has a reno-protective effect against RIF in vivo and in vitro, and the effect is partly linked to nuclear factor-kappa B (NF-κB) pathway related inflammatory response, which indicates that SQP may be a candidate drug for RIF. DOI: 10.52547/ijkd.7546.

The Expression and Molecular Mechanisms of Matrix Metalloproteinase-9 and Vascular Endothelial Growth Factor in Renal Interstitial Fibrosis in Rats

Abstract: To explore a new approach for the treatment of renal interstitial fibrosis (RIF), we detected the expression of matrix metalloproteinase-9 (MMP9) and vascular endothelial growth factor (VEGF). Twenty-four male Sprague Dawley (SD) rats were randomly divided into 2-week normal control (2NC) group, 4-week NC (4NC) group, 2- week unilateral ureteral obstruction (2UUO) group, and 4-week UUO (4UUO) group. We performed left ureteral ligation on UUO groups. Then, we sacrificed the rats of the 2NC group and 2UUO group at 2 weeks and the other groups at 4 weeks after the surgery. Immunohistochemistry and western blot were applied to detect the expression of MMP9, VEGF, fibronectin (FN), type IV collagen (Col-IV), and transforming growth factor-β1 (TGF-β1). MMP9 levels reduced after UUO surgery. Its expression was less in the 4UUO group than in the 2UUO group (P<0.05). The expression of VEGF, TGF- β1, FN, and Col-IV was higher in UUO groups than in NC groups (P<0.05). The expression of these indicators was higher in the 4UUO group than in the 2UUO group (P<0.05). In the correlation analysis, MMP9 levels in UUO groups had a negative correlation with the expression of TGF-β1, VEGF, Col-IV, FN, and RIF index (all P<0.05). In UUO groups, VEGF levels had a positive correlation with the expression of TGF-β1, Col-IV, FN, and RIF index (all P<0.05). In conclusion, with the aggravation of RIF lesions, MMP9 levels decreased, and VEGF levels increased. Whether there is a mutual inhibition relationship between them remains to be confirmed by further experiments.

Improvement on renal interstitial fibrosis in rats with renal failure via TLR4/NF-κB signaling pathway by means of panax notoginseng saponins

Panax notoginseng saponins (PNS) have excellent effects on treating cardiovascular and cerebrovascular diseases, tumors and organ interstitial diseases. This study assessed the effect of PNS on renal interstitial fibrosis (RIF). Four groups of models were firstly created, which included; renal failure model, healthy group, model group, PNS group, and then established TLR4 inhibitor group (TAK-242 group), TLR4 activator group (LPS group), combined PNS and TLR4 inhibitor group (PNS+ TAK-242 group) and combined PNS and TLR4 agonist (PNS+LPS group). TLR4/NF-κB signaling pathway and regulatory mechanism for PNS were observed along with analysis of TGF-β1, α-SMA, Collagen I and FN expressions in kidney tissues. The PNS significantly inhibited changes of renal interstitial fibrosis in rats with renal failure, and this process was related to decreased expressions of TLR4 and NF-κB. The PNS also inhibited the expression of TLR4, and expressions of TGF-β1, α-SMA, Collagen I and FN were down-regulated in kidney cells after using TAK-242, especially in the PNS+TAK-242 group. The PNS can thus significantly inhibit the process of renal fibrosis, and this process is due to the fact that, PNS inhibits the activity of TLR4/NF-κB signaling pathway to down-regulate the expressions of fibrosis-related factors TGF-β1, α-SMA, etc., in exerting its effects.

Retracted: Exploring the Effect of Dapagliflozin on Alcoholic Kidney Injury and Renal Interstitial Fibrosis in Rats Based on TIMP-1/MMP-24 Pathway.

[This retracts the article DOI: 10.1155/2021/6538189.].

Inhibitory Effects of Rhein on Renal Interstitial Fibrosis via the SHH-Gli1 Signal Pathway.

Background Rhein is the main extract of Rheum palmatum L., which has been proved to improve the renal function of chronic kidney disease, but its mechanism is not clear. Therefore, this experiment explored the potential pharmacological effect of rhein on renal interstitial fibrosis rats. Methods This study explores the potential pharmacological action of rhein. In this work, we investigate the potential pharmacological action of rhein in unilateral urethral obstruction (UUO) rats. Thirty Sprague Dawley rats were randomly divided into three groups: sham, UUO, and rhein (rhein-treated UUO rats) groups. The left ureters of the UUO group rats were exposed and bluntly dissected. The rhein group rats were administered an intragastric gavage of rhein (2 mg·kg−1·d−1) for 14 d. Kidney function-related indicators were monitored in these rats, while indexes of pathologic aspects were determined histologically. The expression of α-SMA, TGF-β1, SHH, Gli1, and Snail was quantified using real-time polymerase chain reaction and western blotting. The NRK-49F cells were incubated with and without SHH (100 ng·ml−1) for 48 hours. The SHH-activated NRK-49F cells were incubated with cyclopamine (CNP, 20 umol L−1) or rhein (1 ng·ml−1). The Gli1 and Snail mRNA and protein level were detected. Results In the in vivo experiment, the results exhibited that UUO caused renal pathological damages. However, these changes could be significantly reversed by the administration of rhein. Compared with the untreated UUO group, the rhein group showed reduced kidney tubular atrophy and necrosis, interstitial fibrosis, hyperplasia, and abnormal deposition of extracellular matrix. Rhein reduced the RNA and protein expression of SHH, Gli1, and Snail of the UUO rats. In the in vitro experiment, CNP or rhein treatment decreased the expression of Gli1 and Snail on mRNA and protein levels in SHH-induced NRK-49F cells, suggesting that CNP or rhein suppresses SHH-induced NRK-49F activation. Taken together, these results demonstrated that rhein suppresses SHH-Gli1-Snail signal pathway activation, with potential implications for the treatment of renal fibrosis. Conclusions Treatment with rhein remarkably ameliorated renal interstitial fibrosis in UUO rats by regulating the SHH-Gli1-Snail signal pathway.

Morphological pattern of kidneys in rats with infravesical urinary obstruction following administration of biologically active compositions containing neurotrophic factors

Abstract. The research aimed to study the morphological characteristics of kidneys after intraperitoneal administration of biologically active compositions (BACs) in rats with infravesical obstruction (IVO).
 Methods. IVO was reproduced by surgical ligation. BACs were injected intraperitoneally for 10 days. The morphometric parameters of the kidneys were determined by examining their structure (the areas of renal corpuscle, glomerulus, the cavity of the glomerular capsule, outer and inner diameters of the tubules, the tubular index, the outer diameter and area of the vascular lumen). The experimental animals were divided into the following groups: Group 1 was saved as an intact control group, Group 2 received “Cortexin”, Group 3 was given CMCNMG, Group 4 received BCM, and Group 5 was not treated (U).
 Results. BACs obtained from a culture of native mantle gliocytes (MG) and BCM were involved in the remodeling of the kidneys’ structure being changed during IVO. The renal corpuscle area was found to be increased in groups 2, 4, and 5 by 42.3%, 193.9%, and 72.3%, respectively, compared with the control group. At the same time, the extent of renal corpuscle hypertrophy in group 3 was minimal and approached the control values. The glomerulus area expanded by 35.4%, 181.1%, and 34% in animals of groups 3, 4, and 5, respectively, compared with the control group. However, the difference in the index between group 5 and BAC-treated animals was not significant, except for group 4. The Bowman's capsule area increased by 117.6%, 235.8%, and 186%, in groups 2, 4 and 5, respectively, compared with the control group. Interestingly, the values in groups 1 and 3 were in agreement but differed from group 5. The lowest values of outer and inner diameters of renal tubules were determined in group 3, which were close to those in the control group but significantly different from those of other groups. An increased tubular index (by 1.35 and 1.4 times) was revealed in groups 3 and 4, compared with other groups. The lowest values were found in groups 2 and 5. The maximum values of the average diameter and area of the vessel lumen were determined in groups 3 and 4, and the minimum values were obtained in group 5. It is noteworthy that the indices of these groups were significantly different from those of group 5.
 Conclusions. The research results suggest that the phenomena of glomerulosclerosis, tubular atrophy, and renal interstitial fibrosis in rats can be alleviated, as well as the morphological structure of rat kidneys can be partially restored against the background of IVO after administration of CMCNMG and, to a lesser extent, BCM due to the multidirectional action of neurotrophic factors.

Effect of Bushen Qudu Decoction on TGF-β1/Smads signal transduction pathway in rats with chronic renal failure

Purpose: To study the impact of Bushen Qudu Decoction on renal function, renal tissue morphology and TGF-β1/Smads signal transduction pathway in adenine-induced chronic renal failure rats.Methods: 76 rats were assigned to normal group, model group, uremic clearance group, benazepil group, Bushen Qudu decoction gunshan A group and Bushen Qudu decoction Guiza group. Renal failure was induced in rats using intragastric administration of adenine for 30 days. The expressions of TGF-β1, Smad2, Smad3 and Smad6 were determined with immunohistochemistry. Real-time quantitative PCR was employed to assay the mRNA expression of TGF-β1 in each group, while protein expressions of Smad2, Smad3 and Smad6 were determined with western blot. The scores of glomerular and tubulointerstitial lesions in each group were obtained by histopathological examination.Results: Bushen Qudu decoction significantly reduced BUN and creatinine in rats with chronic renal failure; furthermore, it also lowered the protein expressions of TGF-β1 and SMAD2/3, but Smad6 protein, relative to control (p < 0.05). The TGF-β1mRNA expression was down-regulated (p < 0.05), relative to control group.Conclusion: Bushen Qudu decoction reduces renal interstitial fibrosis in rats and delays the progression of chronic renal failure by regulating TGF-β1/Smads signaling pathway. These findings provide some insight that should facilitate the development of new drugs that would delay the onset of chronic renal failure.

The mTOR inhibitor everolimus attenuates tacrolimus-induced renal interstitial fibrosis in rats

AimsTacrolimus—a widely used immunosuppressant to prevent allograft rejection after organ transplantation—is nephrotoxic, increasing the risk of kidney injury accompanied by kidney fibrosis. The mammalian target of rapamycin (mTOR) inhibitor, everolimus, is an immunosuppressant used together with tacrolimus. Although mTOR signaling inhibition has been demonstrated to exhibit antifibrotic effects, the efficacy of everolimus against tacrolimus-induced kidney fibrosis has not been explored. Therefore, we evaluated the protective effects of everolimus against tacrolimus-induced kidney fibrosis. Main methodsTo assess antifibrotic effect of everolimus against tacrolimus-induced kidney fibrosis, male Wistar rats were subcutaneously administered vehicle or tacrolimus (5 mg/kg per day) and/or everolimus (0.2 mg/kg per day) for 2 weeks after bilateral renal ischemia for 45 min. The antifibrotic effect of everolimus was also assessed using rat kidney fibroblast cell line (NRK-49F). Key findingsTacrolimus administration increased predominant profibrotic cytokine transforming growth factor-β (TGF-β) and fibroblast activation marker α-smooth muscle actin (α-SMA) expression and promoted the infiltration of macrophages in the kidney cortex, resulting in renal interstitial fibrosis in rats. Tacrolimus increased serum creatinine, blood urea nitrogen, kidney injury molecule-1 (KIM-1), and kidney injuries, such as tubular dilation, vacuolization, and glomerular atrophy. Everolimus administration attenuated tacrolimus-induced kidney fibrosis and the associated abnormalities. Everolimus strongly suppressed TGF-β-induced kidney fibroblast activation and extracellular matrix protein expression by the mTOR signaling inhibition. SignificanceWe demonstrated that everolimus attenuates tacrolimus-induced renal interstitial fibrosis in rats. Owing to its protective effect against tacrolimus-induced kidney fibrosis, everolimus may be useful when used concomitantly with tacrolimus.

Exploring the Effect of Dapagliflozin on Alcoholic Kidney Injury and Renal Interstitial Fibrosis in Rats Based on TIMP-1/MMP-24 Pathway.

Objective To establish a rat model of alcoholic kidney injury and detect the expression of TIMP-1/MMP-24 in the kidneys of rats with alcoholic kidney injury at the molecular pathological level, so as to explore the mechanism of alcohol abuse leading to kidney injury and renal interstitial fibrosis as well as the alleviation of alcohol-induced kidney injury and inhibition of renal interstitial fibrosis by dapagliflozin. Methods 48 male rats were randomly divided into 4 groups: control group, alcohol group, alcohol + dapagliflozin group, and alcohol + losartan group, each with 12 rats. Different drugs were administered by gavage for modeling and treatment. Six days later, the rats were sacrificed, blood was collected from the heart to separate the serum, and the blood creatinine (Scr) and urea nitrogen (BUN) contents were detected biochemically. After blood collection, the kidney tissue was taken and fixed in10% neutral formalin. The expression of renal tissue inflammatory factors (CRP, IL-6, and TNF-α) and renal fibrosis indexes (LN, HA, and TGF-β1) were detected; MMP-24 and TIMP-1 in the kidney tissue of rats in different treatment groups were detected, and Smad3 expression was also detected. Results After treatment, the general condition of the alcohol + dapagliflozin group and the alcohol + losartan group improved to different degrees. The weight first decreased and then gradually increased over time. There was no statistical difference in the weight change between the two groups; Compared with the control group, the Scr level, BUN content, renal index, inflammatory factors, and renal fibrosis indexes in the alcohol group were significantly increased (P < 0.05); after 6 weeks of treatment, in the alcohol + dapagliflozin group and alcohol + losartan group, Scr level, BUN content, kidney index, inflammatory factors, and renal fibrosis indexes were significantly decreased (P < 0.05); the expression of MMP-24 in the kidney tissue of the control group was upregulated, and the expression of TIMP-1 and Smad3 was downregulated; MMP-24 expression was downregulated, and TIMP-1 and Smad3 expression was significantly upregulated (P < 0.05) in the rats of the alcohol group. After dapagliflozin and losartan treatment, MMP-24 expression gradually increased and TIMP-1 and Smad3 expression gradually decreased (P < 0.05). Conclusion Long-term large-scale alcohol intake can cause kidney tissue damage and fibrotic lesions. The expression of fibrotic cytokines such as TIMP-1 and Smad3 will increase, and the expression of MMP-24 will be decreased. However, dapagliflozin and losartan have certain therapeutic effects on the abovementioned lesions. The mechanism may be downregulating TIMP-1 and Smad3 and upregulating the expression of MMP-24 and other cytokines in the kidney.

FC 044THE LONG-TERM EFFECTS OF ACUTE KIDNEY INJURY ON INTESTINAL OXALATE-DEGRADING BACTERIA IN RATS

Abstract Background and Aims Gut microbiota is considered an important factor affecting oxalate handling in the intestine. It has been demonstrated that intestinal oxalate secretion provides a complementary route of excretion, and it becomes more evident when kidney function declines. A diversity of gut oxalate-degrading bacteria (ODB) has been hypothesized to play a role in this process. However, there is a general lack of research on the long-term effects of acute kidney injury (AKI) on ODB and their total oxalate-degrading activity (ODA) in fecal microbiota. In this study, we evaluated whether renal dysfunction could affect intestinal ODB and their total ODA in a rat model of glycerol-induced AKI. Method The Male Wistar rats (200-300 g, n=20) on oxalate-free diet were randomly divided into 2 groups. After 24-h of water deprivation, Group 1 (n=10) received an intramuscular injection of 50% glycerol (10 ml/kg of body weight), and Group 2 (n=10) served as control. The numbers of ODB (incubated in a highly selective Oxalate Medium and determined using culture method) and total fecal ODA were measured after injection on days 7 and 70. The method of redoximetric titration with a KMnO4 solution was adopted to evaluate total ODA in fecal microbiota; the results were expressed as % of oxalate degradation per 0.01 g of feces. Renal injury was assessed by histopathological examination, serum creatinine and daily proteinuria levels after removing the animals from the experiment on day 70. Cortical interstitial fibrosis was measured by computerized image analysis on sections stained with picrosirius red. The median (Me) and the interquartile ranges (Q25; Q75) were calculated and compared using the nonparametric Mann-Whitney test. The Spearman correlation coefficient was used to evaluate association between the examined parameters. Results The obtained results demonstrated: 1) after glycerol injection on day 7, no differences were found in the numbers of ODB and total fecal ODA between the experimental and control groups: 5.9 (5.4-6.0) vs 6.0 (5.4-6.4) CFU/g, p=0.65 and 2.0 (0.1-5.0) vs 2.5 (2.0-9.0) %/0.01g, p=0.24, respectively; 2) after AKI initiation on day 70, the numbers of ODB and total fecal ODA were significantly lower in Group I compared with control Group II (Fig. 1); 3) the higher percentage of renal interstitial fibrosis was, the higher total fecal ODA occurred in the experimental rats (Fig. 2). In addition, the number of ODB in feces in Group 1 had an inverse association with serum creatinine (r=-0.52, p=0.006) and 24-h proteinuria levels (r=-0.86, p&amp;lt;0.0001). Conclusion AKI had the long-term negative effects on the quantitative and qualitative characteristics of ODB in fecal microbiota in rats. Moreover, the results of our study confirmed an increasing trend in total fecal ODA according to the aggravation of renal interstitial fibrosis in rats.

Ginaton injection alleviates cisplatin-induced renal interstitial fibrosis in rats via inhibition of apoptosis through regulation of the p38MAPK/TGF-β1 and p38MAPK/HIF-1α pathways.

Ginaton injection (Ginkgo biloba extract; GBE) has been reported to protect against cisplatin-induced acute renal failure in rats. In the present study, the effects and molecular mechanisms of GBE on cisplatin-induced renal interstitial fibrosis were evaluated using a rat model. The rats were intraperitoneally injected with cisplatin once on the first day and a subset of rats were treated with GBE or SB203580 (SB; a specific p38 MAPK inhibitor) daily from days 22 to 40. The levels of N-acetyl-β-D-Glucosaminidase (NAG) in the urine, and of urea nitrogen (BUN) and creatinine (Scr) in the blood were assessed. The damage and fibrosis of renal tissues were evaluated using hematoxylin and eosin staining, as well as Masson's trichrome staining, respectively. Apoptosis in renal tissues was detected using a TUNEL assay. The protein expression levels of α-smooth muscle actin (SMA), collagen 1 (Col I), Bax, Bcl-2, caspase-3/cleaved caspase-3, hypoxia-inducible factor-1α (HIF-1α), TGF-β1 and p38MAPK, as well as the mRNA levels of p38MAPK in renal tissues were investigated. The results showed that GBE markedly reduced the levels of urinary NAG, Scr and BUN, and renal expression of α-SMA and Col I levels were also reduced. Furthermore, GBE significantly reduced renal tissue injury and the relative area of renal interstitial fibrosis induced by cisplatin. GBE effectively reduced the apoptotic rate of renal tissues, the protein expression levels of Bax, cleaved caspase-3, phospho-p38MAPK, TGF-β1 and HIF-1α, as well as the mRNA expression levels of p38MAPK in renal tissues induced by cisplatin, whereas GBE significantly increased Bcl-2 protein expression. SB exhibited similar effects to GBE, although it was not as effective. In summary, the present study is the first to show that GBE significantly alleviated renal interstitial fibrosis following cisplatin-induced acute renal injury. The mechanisms by which GBE exhibited its effects were associated with the inhibition of apoptosis via downregulation of the p38MAPK/TGF-β1 and p38MAPK/HIF-1α signaling pathways.

Metformin attenuates renal interstitial fibrosis through upregulation of Deptor in unilateral ureteral obstruction in rats

Renal interstitial fibrosis (RIF) is a common pathological process that accompanies chronic kidney disease (CKD) and that progresses to end-stage renal failure (ESRD). Accumulating evidence has revealed that persistent mammalian target of rapamycin (mTOR) activation in kidneys is closely associated with the occurrence and progression of CKD. The DEP domain-containing mTOR interacting protein (Deptor) is an endogenous negative regulator of mTOR. Metformin can attenuate renal fibrosis in an animal model of diabetic nephropathy. Previous studies demonstrated that metformin can attenuate renal fibrosis in several models of CKD. However, the precise mechanisms of this effect are not well understood. The present study aimed to examine the mechanism of action of metformin on unilateral ureteral obstruction (UUO)-induced RIF in rats in vivo. Sprague-Dawley rats were randomly divided into a sham-operated group, three UUO groups examined at different time points (3, 7 and 14 days after UUO surgery), and three metformin-treated groups, treated with three different concentrations of metformin. The metformin-treated groups were administered metformin orally every day for 14 consecutive days following surgery. The protein expression levels of Deptor, α-smooth muscle actin (α-SMA), phosphorylated (p-)mTOR, p-ribosomal protein S6 kinase (p-p70S6K) and CD68 were assessed. The present results suggested that, following UUO, there was a significant reduction of Deptor expression, and an increase in collagen deposition in the extracellular matrix over time, accompanied by an increased expression of several proteins including CD68, α-SMA, p-mTOR and p-p70S6K. Notably, metformin treatment reversed these effects. In conclusion, the present results suggested that metformin attenuated RIF of UUO rats, and the mechanism of action was found to be associated with the increase in Deptor expression and inhibition of the mTOR/p70S6K pathway in the kidneys of UUO rats.

Transcriptomic analysis of the mechanisms of alleviating renal interstitial fibrosis using the traditional Chinese medicine Kangxianling in a rat model

Renal interstitial fibrosis (RIF) is currently recognized as a crucial mechanism of the pathogenesis of chronic kidney disease (CKD). Kangxianling (KXL, anti-fibrin) is a traditional Chinese medicine that has been proven to significantly reduce the levels of ECM deposition and inhibit renal fibrosis.To characterize the mechanisms and drug targets of KXL, we established a RIF rat model and treated the rats with KXL and losartan. Histological analyses validated the establishment of the RIF model and the treatment effect of KXL. Multiple levels of transcriptomic datasets were generated using lncRNA, mRNA and microRNA sequencing of kidney tissues. Functional annotations and pathway analyses were performed to unravel the therapeutic mechanisms.A multi-level transcriptomic regulatory network was built to illustrate the core factors in fibrosis pathogenesis and therapeutic regulation. KXL and losartan significantly reduced the progression of RIF, and a better therapeutic effect was shown with higher concentrations of KXL. According to the cluster analysis results of the RNA-seq data, the normal control (NC) and high concentration of KXL (HK) treatment groups were the closest in terms of differentially expressed genes. The WNT, TGF-β and MAPK pathways were enriched and dominated the pathogenesis and therapy of RIF. miR-15b, miR-21, and miR-6216 were upregulated and miR-107 was downregulated in the fibrosis model. These small RNAs were shown to play critical roles in the regulation of the above fibrosis-related genes and could be inhibited by KXL treatment. Finally, based on the lncRNA datasets, we constructed a mRNA-lncRNA-miRNA coexpression ceRNA network, which identified key regulatory factors in the pathogenesis of kidney fibrosis and therapeutic mechanisms of KXL. Our work revealed the potential mechanism of the Chinese medicine Kangxianling in inhibiting renal interstitial fibrosis and supported the clinical use of KXL in the treatment of kidney fibrosis.

FoxM1 inhibition ameliorates renal interstitial fibrosis by decreasing extracellular matrix and epithelial–mesenchymal transition

FoxM1 is a transcriptional regulator involved in tumor development, pulmonary fibrosis, and cardiac fibrosis. However, its role in renal interstitial fibrosis (RIF) has yet to be elucidated. We established a TGF-β1-stimulated human proximal tubular epithelial cell (HK-2) model in vitro and a unilateral ureteral obstruction (UUO)-induced rat RIF model in vivo. FoxM1 inhibition was achieved by siRNA interference in vitro and by injecting thiostrepton into UUO-induced RIF rats in vivo. The degree of renal damage and fibrosis were determined by histological assessment via hematoxylin and eosin (H&E) staining. Immunohistochemistry, western blots, and qPCR were used to determine the expression levels of FoxM1, Collagen I, E-cadherin, α-SMA, and Snail1. Our results showed that FoxM1 inhibition could ameliorate RIF and reduce the deposition of Collagen I. H&E staining revealed that renal structural damage, inflammatory cell infiltration, and ECM deposition were significantly attenuated by thiostrepton treatment in the UUO rats. Furthermore, FoxM1 downregulation significantly suppressed epithelial-to-mesenchymal transition, as evidenced by decreased protein and mRNA expression levels of α-SMA and Snail1 and a significant increase in protein and mRNA expression levels of E-cadherin. Collectively, these results suggested that FoxM1 inhibition could be a novel therapeutic strategy for the treatment of RIF.

Niao Du Kang Mixture Increases the Expression of mir-129-5p to Relieve Renal Fibrosis.

Objective To investigate the efficacy of Niao Du Kang (NDK) mixture in renal fibrosis of rats and to explore the mechanism underlying the effect of NDK on renal fibrosis. Methods Unilateral ureteral obstruction (UUO) was used to replicate a rat renal interstitial fibrosis model. The drug-administered groups were given 20 ml/kg (NDK-H), 10 ml/kg (NDK-M), and 5 ml/kg (NDK-L) NDK mixture once a day for 21 days beginning 48 hours after surgery. The 24-hour urine protein and serum creatinine (CR) levels in the sham group rats, UUO rats, and NDK mixture-treated rats were measured after the last administration. The pathological changes of rat kidney tissue were observed by HE staining. The degree of fibrosis was observed by Masson's staining and scored. The expression levels of TGF-β, α-SMA mRNA, and mir-129-5p in kidney were detected by qRT-PCR. HK-2 cells were treated with 5 ng/ml TGF-β to induce HK-2 cell fibrosis. The expression levels of TGF-β, α-SMA mRNA, and mir-129-5p in HK-2 cells were detected by qRT-PCR. TargetScan predicted the target gene of mir-129-5p, HK-2 cells were transfected with mir-129-5p mimic, and an overexpressed mir-129-5p HK-2 cell model was constructed. qRT-PCR was used to detect the expression of PDPK1 mRNA. Western blot was used to detect the expression of PDPK1, AKT, and p-AKT in HK-2 cells induced by TGF-β and in UUO rats. Results NDK mixture significantly reduced the 24-hour urine protein and CR levels of UUO rats. HE staining showed that the NDK mixture group exhibited a significantly reduced degree of renal interstitial fibrosis. NDK mixture also reduced the expression of TGF-β and α-SMA, and the middle-dose group showed a better therapeutic effect. In vitro studies showed that NDK mixture-containing serum increased the expression of mir-129-5p to reduce renal fibrosis. In addition, NDK mixture increased the expression of mir-129-5p in vivo. Further studies indicated that mir-129-5p could target PDPKl to reduce its expression. The NDK-containing serum group also exhibited reduced expression of PDPK1. Conclusion NDK mixture can significantly improve renal function and improve renal fibrosis in UUO model rats. Furthermore, NDK mixture can inhibit the expression of PDPK1 by upregulating the expression of mir-129-5p and then inhibiting the PI3K/AKT pathway to improve renal fibrosis.

Rhubarb and Astragalus Capsule Attenuates Renal Interstitial Fibrosis in Rats with Unilateral Ureteral Obstruction by Alleviating Apoptosis through Regulating Transforming Growth Factor beta1 (TGF-β1)/p38 Mitogen-Activated Protein Kinases (p38 MAPK) Pathway.

BackgroundRhubarb and astragalus capsule (RAC) has been used in the clinical treatment of chronic kidney disease for decades. However, the mechanism of RAC has not been fully elucidated. This study aimed to investigate the protective effect and mechanisms of RAC on unilateral ureteral obstruction (UUO)-induced renal interstitial fibrosis.Material/MethodsThe main components of RAC are detected by high-performance liquid phase (HPLC). A rat model of UUO was established, and a subset of rats underwent treatment with RAC. Renal function and renal pathology were examined at 14 days and 21 days after the UUO operation. Renal cell apoptosis was detected by TUNEL staining. The levels of Bcl-2 and Bax in the kidney were examined by western blotting, and the levels of collagen I, α-SMA, transforming growth factor (TGF)-β1, and p38 MAPK in the kidneys were detected by immunohistochemistry.ResultsHigh-performance liquid phase chromatography showed that RAC contained 1.12 mg/g aloe-emodin, 2.25 mg/g rhein, 1.75 mg/g emodin, and 4.50 mg/g chrysophanol. Administration of RAC significantly decreased the levels of urinary N-acetyl-β-D-glucosaminidase (NAG), serum blood urea nitrogen (BUN), and creatinine (Scr) and also reduced renal tissue damages and interstitial fibrosis induced by UUO in rats. Moreover, the increased levels of collagen I, α-SMA, TGF-β1, p38 MAPK, and the Bax/Bcl-2 ratio, as well as cell apoptosis in the kidney, were induced by UUO, and were all found deceased by RAC treatment.ConclusionsRAC can improve the renal interstitial fibrosis induced by UUO, and the mechanism may be related to inhibition of renal tubular cell apoptosis via TGF-β1/p38 MAPK pathway.

Human umbilical cord blood mononuclear cells protect against renal tubulointerstitial fibrosis in cisplatin-treated rats

Currently, there is no effective method to prevent renal interstitial fibrosis after acute kidney injury (AKI). In this study, we established and screened a new renal interstitial fibrosis rat model after cisplatin-induced AKI. Our results indicated that rats injected with 4 mg/kg cisplatin once a week for two weeks after firstly administrated with 6.5 mg/kg loading dose of cisplatin could set up a more accurate model reflecting AKI progression to renal interstitial fibrosis. Then, we investigated the effects and possible mechanisms of human umbilical cord blood mononuclear cells (hUCBMNCs) on renal tubular interstitial fibrosis after cisplatin-induced AKI. In rats injected with hUCBMNCs for four times, level of matrix metalloproteinase 7 (MMP-7) in serum and urine, urinary albumin/creatinine ratio, tubular pathological scores, the relative collagen area of the tubulointerstitial region, endoplasmic reticulum dilation and the mitochondrial ultrastructural damage were significantly improved. The level of reactive oxygen species, α-smooth muscle actin (α-SMA), [NOD]-like pyrin domain containing protein 3 and cleaved-Caspase 3 in renal tissue decreased significantly. However, in rats injected with hUCBMNCs for two times, no significant difference was discovered in MMP-7 levels and urinary albumin/creatinine ratio. Although expression of α-SMA and the percentage areas of collagen staining in tubulointerstitial tissues were ameliorated in rats injected with hUCBMNCs for two times, the effects were significantly weaker than those in rats injected with hUCBMNCs for four times. Taken together, our study constructed a highly efficient, duplicable novel rat model of renal fibrosis after cisplatin-induced AKI. Multiple injections of hUCBMNCs may prevent renal interstitial fibrosis after cisplatin-induced AKI.

Human umbilical cord blood mononuclear cells protect against renal tubulointerstitial fibrosis in cisplatin-treated rats

Currently, there is no effective method to prevent renal interstitial fibrosis after acute kidney injury (AKI). In this study, we established and screened a new renal interstitial fibrosis rat model after cisplatin-induced AKI. Our results indicated that rats injected with 4 mg/kg cisplatin once a week for two weeks after firstly administrated with 6.5 mg/kg loading dose of cisplatin could set up a more accurate model reflecting AKI progression to renal interstitial fibrosis. Then, we investigated the effects and possible mechanisms of human umbilical cord blood mononuclear cells (hUCBMNCs) on renal tubular interstitial fibrosis after cisplatin-induced AKI. In rats injected with hUCBMNCs for four times, level of matrix metalloproteinase 7(MMP-7)in serum and urine, urinary albumin/creatinine ratio, tubular pathological scores, the relative collagen area of the tubulointerstitial region, endoplasmic reticulum dilation and the mitochondrial ultrastructural damage were significantly improved. The level of reactive oxygen species, α-smooth muscle actin (α-SMA), [NOD]-like pyrin domain containing protein 3 and cleaved-Caspase 3 in renal tissue decreased significantly. However, in rats injected with hUCBMNCs for two times, no significant difference was discovered in MMP-7 levels and urinary albumin/creatinine ratio. Although expression of α-SMA and the percentage areas of collagen staining in tubulointerstitial tissues were ameliorated in rats injected with hUCBMNCs for two times, the effects were significantly weaker than those in rats injected with hUCBMNCs for four times. Taken together, our study constructed a highly efficient, duplicable novel rat model of renal fibrosis after cisplatin-induced AKI. Multiple injections of hUCBMNCs may prevent renal interstitial fibrosis after cisplatin-induced AKI.

Effect of enalapril on apoptosis of renal tubular epithelial cells in renal interstitial fibrosis in rats

To observe the effect of enalapril on the apoptosis of renal tubular epithelial cells in renal interstitial fibrosis rats and to explore the mechanism of enalapril on renal interstitial fibrosis. Methods: Twenty-four SD male rats were randomly divided into a sham operation group, a model group and an enalapril group (n=8 in each group). The rats in the model group and the enalapril group underwent the operation of left urethral obstruction to establish the animal model of unilateral urethral obstruction (UUO). Fourteen days later after the operation, all rats were sacrificed and their obstructed kidneys were collected for HE and Masson staining to observe the pathological change of renal tissues. Terminal deoxynucleotidyl transferase-mediated (dUTP) nick end-labeling (TUNEL) staining was used to detect the apoptosis of renal tubular epithelial cells. Immunohistochemistry and Western blotting were used to detect the protein expression of Fas-associated death domain (FADD), apoptotic protease activating factor-1 (APAF-1) and C/EBP homologous protein (CHOP). Results: Compared with the sham operation group, the renal interstitial injury index and renal interstitial fibrosis index were significantly increased in the model group (P<0.05). Compared with the model group, the renal interstitial injury index and renal interstitial fibrosis index were both significantly decreased in the enalapril group (P<0.05). Compared with the sham group, the apoptosis rate of renal tubular epithelial cells was increased in the model group (P<0.05); compared with the model group, the apoptosis rate of renal tubular epithelial cells was significantly reduced in the enalapril group (P<0.05). The protein levels of FADD, APAF-1 and CHOP in the model group were significantly elevated than those in the sham group (all P<0.05), which were reversed in presence of enalapril (all P<0.05). Conclusion: Enalapril can alleviate renal interstitial fibrosis through inhibiting apoptosis of renal tubular epithelial cells in UUO rats.

Protective effects of GPR120 agonist-programmed macrophages on renal interstitial fibrosis in unilateral ureteral obstruction (UUO) rats

Macrophages in the kidney play different roles in renal interstitial fibrosis (RIF) depending on their phenotypes. M2 phenotype macrophages are believed to protect the kidney against RIF. Free fatty acid receptor GPR120 is expressed in macrophages, and its activation induces macrophage transition to M2 phenotype. In this study, the effects of GPR120 agonist-programmed macrophages on RIF were investigated. The peritoneal macrophages collected from rats were incubated with GPR120 agonist TUG891 in vitro for 24 h, and then they were transplanted autologously to the kidney with ureteral obstruction by intrarenal injection for 7 days on the same day following unilateral ureteral obstruction (UUO) operation. RIF was identified by Masson trichrome histological staining, and the expression of RIF-related proteins was analyzed by immunohistochemistry and western blot. It was observed that TUG891-programmed macrophages up-regulated the expression of CD206 and arginase-1 while the expression of interleukin-6 and tumor necrosis factor-α were down-regulated. RIF in rats was significantly increased following UUO, which was markedly alleviated by TUG891-programmed macrophages but not untreated macrophages. TUG891-programmed macrophages inhibited the abnormal expression of TGF-β1 and SMAD2. The abnormal expression of epithelial-mesenchymal transition (EMT)-related proteins including vimentin, α-SMA and β-catenin was also significantly decreased in rats with transplantation of TUG891-programmed macrophages as compared to UUO rats. This study suggests that autologous administration of peritoneal macrophages programmed in vitro by GPR120 agonist to kidney has a protective effect against RIF following UUO.