microRNA-126在糖尿病肾病内皮细胞损伤中的调控机制及肾康丸干预研究

Glomerular vascular endothelial cell injury is one of the important mechanism in the occurrence and development of diabetic nephropathy. It is showen that microRNA-126 plays an important role in the endothelial cell injury，which can regulate VEGF and VCAM-1 expression in the endothelial cells. Our previous study found that the expression of microRNA-126 was decreased in glomerular vascular endothelial cell.However, it is unclear what is the role of microRNA-126 in the pathogenesis of diabetic nephropathy. In order to get the evidence that microRNA-126 play an important role in the endothelial cell injury of diabetic nephropathy and clarify its mechanism, our research will use the methords, such as carrier building，cell transfection，Western-Blot，and qRT-PCR. Shen-Kang pill is prescribed in benefiting for activating blood circulation，and made good curative effect in clinical treatment of diabetic nephropathy. Our previous study found that Shen-Kang pill can regulate the expression of microRNA and effectively inhibit the inflammatory reaction of diabetic nephropathy. Based on the above result, our research will study the role of Shen-Kang pill in regulating microRNA-126 and its relative signal pathway. We expect that our research can enrich the traditional Chinese medicine treatment mechanism for diabetic nephropathy and explore new thought and method for the prevention and control of diabetic nephropathy.

肾小球血管内皮细胞损伤是糖尿病肾病发生发展的重要机制之一。研究发现，microRNA-126可调控内皮细胞中VEGF及VCAM-1的表达，在血管内皮损伤中起着重要作用，我们前期研究也发现，microRNA-126在糖尿病肾病肾小球血管内皮细胞中表达下调，但其在糖尿病肾病发病中的作用尚不清楚。本项目拟采用载体构建、细胞转染、Western-Blot、qRT-PCR等方法，获得microRNA-126在糖尿病肾病内皮细胞损伤中的证据，阐明其作用机制。肾康丸从益气活血立法处方治疗糖尿病肾病在临床上取得良好疗效。我们前期研究发现肾康丸可调节microRNA的表达，并可有效抑制糖尿病肾病炎症反应，基于此结果，本研究将观察肾康丸在microRNA-126及其相关信号通路中的作用，以期丰富中药治疗的疗效机理，为糖尿病肾病的防治探索新的思路和方法。

糖尿病肾病(DN)是糖尿病最常见、最严重的全身性微血管并发症之一。肾小球内皮细胞损伤是DN发生发展的重要机制。microRNA-126在血管内皮损伤中起着重要作用，但其在DN发病中的作用尚不清楚。本项目旨在通过体内外研究，探讨DN内皮损伤的机制以及肾康丸防治DN的可能靶点。. 研究在成功建立DN大鼠模型的基础上，证实了肾康丸对DN大鼠肾损伤的保护作用，结果表明其可显著减轻病变大鼠肾脏的炎症损伤，减少24小时尿蛋白定量，减轻肾脏病理损伤。在进一步的研究中发现，其可上调miRNA-126表达，降低VEGF、VCAM-1、p38MAPK、TNF-α、NF-kB的表达水平，显示其可能是通过调控miRNA-126及其相关通路基因的表达而发挥做干预作用。为进一步证实该作用机制，我们体外培养了人肾小球内皮细胞(RGEC)，验证miRNA-126对该通路的调控作用，并明确肾康丸的作用机制。结果发现，miRNA-126在高糖培养的RGEC中低水平表达，过表达miRNA-126可下调VEGF、VCAM-1、p38MAPK、TNF-α、NF-kB的表达水平，应用p38MAPK抑制剂后，该效应消失，提示p38MAPK是miRNA-126下游调控通路。研究再次表明，肾康丸可增强miRNA-126在RGEC中的表达水平，抑制下游的炎症级联反应进而保护RGEC。. 综上，课题研究发现microRNA-126在DN内皮细胞炎症损伤中发挥了重要的调控作用，该作用是通过p38MAPK信号通路实现的。肾康丸可通过调节microRNA-126的表达，有效抑制DN炎症反应，保护肾功能，延缓DN的进展。