背景:2型心肾综合征(CRS)是慢性心力衰竭患者的进行性肾功能不全,但其病理生理学仍不清楚。中药真武汤在2-CRS的防治中发挥着重要作用,然而,其作用机制尚不清楚。
目的:本研究的目的是研究ZWD对2-CRS肾纤维化的改善作用是否与调节miR-451表达从而介导TLR4/NF-κB/HIF-1α环有关。
方法:采用结扎冠状动脉左前降支+3/4肾切除术建立2型CRS大鼠模型,并随机分为对照组,Sham,型号,卡托普利,ZWD-L,ZWD-M和ZWD-H基团。ZWD干预4周后,通过血尿和心脏超声观察其对2型CRS大鼠心肾功能的影响。HE观察肾组织形态学改变,Masson和PASM染色。TLR4、NF-κB的蛋白和mRNA表达,免疫组化和qPCR检测肾组织中HIF-1α和IκBα的表达。免疫荧光法检测肾组织中NF-κB和HIF-1α蛋白的表达。Westernblot和qPCR检测MCP-1、ICAM-1、IL-1β、IL-6,TGF-β,α-SMA,FN,肾组织中的Smad2、Smad3和E-cadherin。采用PCR检测肾组织中miR-451mRNA的蛋白表达水平。
结果:在这项研究中,我们发现ZWD能够降低Scr的表达,BUN,NT-proBNP,和24小时尿蛋白定量,升高LVEF,FS,CO,并降低2型CRS大鼠的LVIDS水平,以及减轻肾间质纤维化和改善肾小管肿胀。此外,真武汤上调肾组织miR-451表达,抑制TLR4、NF-κB表达,以及HIF-1α蛋白和基因,抑制炎症因子和纤维化相关因子的表达。
结论:ZWD能够上调肾组织中miR-451的表达,抑制TLR4/NF-κB/HIF-1α反应环,然后抑制炎症因子和纤维化相关因子的表达,改善肾脏纤维化,延缓2型CRS的病理过程。
BACKGROUND: Type 2 cardiorenal syndrome (CRS) is a progressive renal insufficiency in patients with chronic heart failure, but its pathophysiology is still unclear. The Chinese medicine Zhenwu Decoction plays an important role in the prevention and treatment of 2-CRS, however, its mechanism of action remains unknown.
OBJECTIVE: The aim of this study was to investigate whether the ameliorative effect of ZWD on 2-CRS renal fibrosis is related to the modulation of miR-451 expression and thus mediating the TLR4/NF-κB/HIF-1α loop.
METHODS: A type 2 CRS rat model was constructed using ligation of the left anterior descending branch of the coronary artery + 3/4 nephrectomy, and randomly divided into Control, Sham, Model, Captopril, ZWD-L, ZWD-M and ZWD-H groups.After 4 weeks of ZWD intervention, its effects on cardiac and renal functions of type 2 CRS rats were observed by hematuria and cardiac ultrasonography. Changes in kidney tissue morphology were observed by HE, Masson and PASM staining. The protein and mRNA expression of TLR4, NF-κB, HIF-1α and IκBα in kidney tissues were detected by immunohistochemistry and qPCR. Immunofluorescence was used to detect the protein expression of NF-κB and HIF-1α in renal tissues. Western blot and qPCR were used to detect the protein expression of MCP-1, ICAM-1, IL-1β, IL-6, TGF-β, α-SMA, FN, Smad2, Smad3, and E-cadherin in renal tissues. PCR was used to detect the protein expression of miR-451mRNA expression level in kidney tissues.
RESULTS: In this study, we found that ZWD was able to reduce the expression of Scr, BUN, NT-proBNP, and 24-hour quantitative urine protein, elevate LVEF, FS, CO, and reduce the level of LVIDS in type 2 CRS rats, as well as attenuate renal interstitial fibrosis and improve tubular swelling. In addition, Zhenwu Decoction up-regulated the expression of miR-451 in renal tissues and inhibited the expression of TLR4, NF-κB, and HIF-1α proteins and genes, which in turn inhibited the expression of inflammatory factors and fibrosis-related factors.
CONCLUSIONS: ZWD was able to up-regulate the expression of miR-451 in renal tissues, inhibit the TLR4/NF-κB/HIF-1α response loop, and then inhibit the expression of inflammatory factors and fibrosis-related factors, improve renal fibrosis, and delay the pathological process of type 2 CRS.