基于miR-320a/AR信号轴探讨淫羊藿苷干预糖尿病肾间质纤维化的机制研究

The activation and proliferation of renal fibroblasts is the central event of the occurrence and development of renal interstitial fibrosis. Many studies have suggested that the modification of miRs is involved in regulating renal fibroblast activation and proliferation. However, the pathogenesis of renal interstitial fibrosis remains unclear, and there is still no effective drug to treat this disease. Previously, our research team revealed that miR-320a and androgen receptor (AR) were probably involved in regulating the activation and proliferation of renal fibroblasts, but interactions between them and molecular mechanisms lied beneath them are yet to be elucidated. Previous studies demonstrated that icarrin possessed a clear efficacy against diabetic nephropathy and in improving renal function, whereas its mechanisms of treating renal interstitial fibrosis are still needed to be clarified. In our research, we aim to investigate the protective role of icarrin in reversing renal interstitial fibrosis caused by diabetic nephropathy via miR-320a-AR axis and its downstream transcriptional regulatory network, especially to explore the role of miR-320a-AR axis in the progression of diabetic renal interstitial fibrosis and the interference of icarrin to the axis. The project will use modern medical methods and methods to explore the mechanism of traditional Chinese medicine, and lay the foundation for the development of new drugs for diabetic complications.

肾脏成纤维细胞活化增殖是肾脏间质纤维化发生发展的中心事件。研究提示miRs修饰参与调控肾脏成纤维细胞活化增殖。肾脏间质纤维化发病机制尚不清楚，尚缺有效治疗药物。课题组前期研究发现，miR-320a与AR性激素受体可能参与调节肾脏成纤维细胞活化增殖发生过程，但是两种调控方式的互作关系、调控分子作用机制有待阐明。前期研究表明淫羊藿苷有明确的抗糖尿病肾病作用，具有改善肾功能的药效。淫羊藿苷治疗糖尿病肾脏间质纤维化的机制有待阐明。本项目拟通过建立大鼠糖尿病肾纤维化动物模型和体外培养活化增殖细胞模型，研究淫羊藿苷通过miR-320a/AR信号轴及下游转录调节网络改善糖尿病肾脏间质纤维化的作用，重点探讨miR-320a/AR信号轴在糖尿病肾脏间质纤维化过程中的作用，明确淫羊藿苷对miR-320a/AR信号轴的扰动。本项目将运用现代医学手段和方法探究传统中药作用机理，为研发糖尿病并发症新药奠定基础。

肾脏间质纤维化是糖尿病肾病发生发展的中心事件，其发病机制尚不清楚，缺乏有效治疗药物。课题组前期研究发现，雄激素受体（Androgen Receptor，AR）可能通过与miRs相互作用参与调节肾脏间质纤维化的发生过程，但是相关的分子作用机制有待阐明。前期研究结果表明淫羊藿苷有明确的抗糖尿病肾病作用，但是其治疗糖尿病肾脏间质纤维化的机制尚未阐明清楚。本项目拟通过建立大鼠糖尿病肾纤维化动物模型和体外培养细胞模型，研究淫羊藿苷通过调节AR及下游转录调节网络改善糖尿病肾脏间质纤维化的作用，重点探讨AR与miRs相互作用在糖尿病肾脏间质纤维化过程中的作用，明确淫羊藿苷对AR的调节作用及作用机制。研究结果显示，miR-320a在糖尿病肾病大鼠肾脏内显著升高，而淫羊藿苷可以通过抑制miR-320a及其靶基因BMP6缓解糖尿病大鼠肾纤维化。文献研究已表明miR-320a对AR具有显著的抑制作用，基于此，进一步深入探究了AR及AR下游对糖尿病肾纤维化的调节作用及淫羊藿苷的干预作用，实验结果表明，淫羊藿苷可以通过直接激活AR改善糖尿病肾脏纤维化，机制探究证明，淫羊藿苷可以通过激活AR下调NF-κB抑制肾成纤维细胞活化增殖，同时可以通过调节miR-192-5p/GLP-1R通路抑制肾小管上皮细胞向成纤维细胞转化和诱导RKIP抑制肾小球内皮细胞向成纤维细胞转化，进而发挥改善糖尿病肾脏间质纤维化的作用。同时，我们还对淫羊藿苷改善糖尿病肾病的作用进行拓展研究，结果显示，淫羊藿苷可以通过激活GPER，介导p62依赖性Keap1降解和Nrf2激活抑制系膜细胞基质生成，抑制IKKβ信号通路缓解糖尿病肾病中的足细胞胰岛素抵抗，进而改善糖尿病肾病。以上研究结果，进一步揭示了糖尿病肾病的发病机理，阐明了淫羊藿苷对糖尿病肾病的治疗作用及作用机制，为淫羊藿苷应用于临床治疗糖尿病肾病奠定一定的理论基础。