基于肾小球内皮细胞eNOS的“代谢记忆”效应研究黄芪甲苷在糖尿病肾病早期的作用及机制

Abstract: To be difficultly cured on dominant proteinuria in diabetic nephropathy (DN) , the world's latest medical opinion is currently more attention to early detection, diagnosis, and management, especially early epigenetic modifications induced by "metabolic memory". It is a nice chance to prevent early diabetic nephropathy. Our previous study found that microalbuminuria was shown and abnormal gene expression of eNOS in 7-week-old OLETF diabetic rats, and these abnormal changes were inhibited by Astragaloside Ⅳ. Therefore, the hypothesis of early pathological mechanisms of DN was revealed by immunoprecipitation sequencing from eNOS histone methylation in glomerular endothelial cells. The pharmacological mechanism of Astragaloside Ⅳ was explored in glomerular endothelial cell of eNOS histone methylation、uncoupled, reactive oxygen species, endothelial cell apoptosis by cells and promoter experiment. To explain the connotation of astragaloside IV treatment on DN in traditional Chinese medicine "Cure and Prevent disease".

由于糖尿病肾病（DN）显性蛋白尿期的病情进行性进展和难治愈化，目前世界最新的医学观点更重视早期治疗。本课题组前期研究中发现，黄芪甲苷有效的改善了7周龄OLETF糖尿病大鼠升高的微量白蛋白尿和降低的eNOS基因表达，以及短暂高糖刺激肾小球内皮细胞，使得转染在细胞中结合H3K4m1抗体eNOS启动子降低的荧光素酶活性升高。 因此本项目拟从肾小球内皮细胞的eNOS基因组蛋白修饰入手，通过组蛋白赖氨酸甲基转移酶Set7突变、免疫复合物共沉淀和高通量测序法，探索黄芪甲苷对eNOS启动子区基因组蛋白修饰的影响。在细胞和分子水平明确黄芪甲苷对肾小球内皮细胞的NO、解偶联、活性氧簇、内皮细胞凋亡的调控机制，揭示DN早期病理机制，阐明黄芪甲苷具有治疗早期DN的中医“治未病”内涵，为临床救治DN奠定理论基础。

本课题主要是从肾小球内皮细胞的eNOS基因组蛋白修饰入手，通过组蛋白赖氨酸甲基转移酶Set7突变、免疫复合物共沉淀、以及CHIP-seq 的高通量测序，从富集Top20 的通路中筛选出来的eNOS启动子组蛋白修饰的MAP4K3基因，发现黄芪甲苷通过影响组蛋白转移酶Set7表达抑制eNOS启动子区H3K4me1修饰的MAP4K3基因，从而抑制eNOS表达，抑制ROS过度释放，达到保护肾脏的作用，进而抑制糖代谢记忆及持续高糖导致的肾损伤。