(前)肾素受体过表达对糖尿病心肌病心肌纤维化的影响

Recent study showed that the (pro)renin receptor (PRR) is considered as a novel bioactive molecule of the renin-angiotensin system (RAS) and it plays an important role in the pathogenesis of DCM and its complications, but little is known about the exact effect of PRR on myocardial fibrosis. This study evaluates the effect of PRR gene overexpression on myocardial fibrosis. In vivo study, diabetes was induced by a single intraperitoneal injection of streptozotocin (STZ). Twelve weeks after STZ injection, rats were further divided into a recombinant PRR expressing vector (Ad PRR)， a control vector AdEGFP（AdEGFP）， Control，Ad-PRR+Losartan，Losartan, Ad-PRR+ ERK inhibitor, Ad-PRR + ERK inhibitor +Losartan groups. The extent and mechanism of myocardial fibrosis were evaluated by immunohistochemistry and Western blot, the activity of matrix metalloproteinases(MMP) MMP3 and MMP9 were evaluated by Zymography. The activation of PRR can elicit a series of AngII-independent effects, and the effects that PRR promotes fibrosis gene expression via a MAPK signaling pathway and NADPH-dependent mechanism were evaluated .In vitro study, the collagen protein expression in cardiac fibroblast after PRR gene transfection were also evaluated. This study want to explore the effect and mechanism of PRR overexpression on myocardial fibrosis, and provide new target for treatment of DCM.

为了探讨（前）肾素受体（PRR）在糖尿病心肌病（DCM）心肌纤维化中的机制及意义，本研究构建PRR腺相关病毒载体（Ad-PRR），建立DCM大鼠模型，将DCM大鼠随机分为7组：（1）Ad-PRR组，（2）Ad-EGFP组，（3）DCM对照组，（4）Ad-PRR组+Losartan组，（5）Losartan组。（6）Ad-PRR+ ERK抑制剂组, （7）Ad-PRR + ERK抑制剂 +Losartan组。应用免疫组化、蛋白印迹及酶谱技术，检测PRR过表达对DCM心肌胶原纤维及基质金属蛋白酶(MMP)MMP-3,MMP-9蛋白及活性的表达；重点探讨“PRR通过AngII非依赖的途径激活MAPK-氧化应激-心肌纤维化”这一通路在DCM纤维化中的作用。体外实验探讨PRR过表达对高糖刺激下的成纤维细胞分泌胶原纤维的影响，目的在于探讨PRR过表达对心肌纤维化的影响及机制 ，为DCM治疗提供新靶点。

糖尿病心肌病（DCM）的发病率及病死率高，治疗无有效的办法。目前研究已证实肾素血管紧张素系统（RAS）的新成员：（前）肾素受体（PRR）与糖尿病及其并发症的发生密切相关，并发现糖尿病中PRR表达增多，从而参与了DCM的病理过程，但目前尚无有关抑制PRR基因治疗DCM的报道。本研究构建PRR的腺病毒载体，建立DCM大鼠模型，探讨PRR过表达及PRR小干扰RNA对DCM的治疗作用。将DCM大鼠随机分组：PRR干预组、PRR小干扰RNA、EGFP空载体组及DCM对照组，应用超声心动图及免疫组化等技术，检测PRR过表达及PRR小干扰RNA对DCM的心功能、病理学及心肌胶原纤维表达的影响；体外实验探讨PRR过表达及PRR小干扰RNA转染对高糖刺激下的心肌细胞及成纤维细胞分泌I型及III型胶原纤维的影响，目的在于探讨PRR过表达及PRR小干扰RNA基因转染对DCM心功能及心肌纤维化的作用 ，为DCM的治疗提供新思路。