有氧运动通过LncRNAs调控miR-492/resistin表达改善主动脉内皮胰岛素抵抗的机制研究

Insulin resistance (IR)-induced vascular endothelial injury is an initiating factor of T2DM vascular complications. Exercise is the basis for the treatment of T2DM and can obviously lower the morbidity of diabetes and pre-diabetes by improving IR. The mechanism underlying the exercise reducing IR is still unclear at present. During recent years, the model of a novel non-coding RNA (ncRNA)- ncRNA interaction network regulation mechanism, namely long-chain non-coding RNA (lncRNA) regulating the expression of miRNA has been verified during the onset of multiple diseases.The previous study conducted by the project group showed that negative regulation of resistin by miR-492 is possibly the important mechanism of swimming training improving aortic endothelial IR and relieving endothelial injury of ApoE-/- mouse. Based on the previous study, the project team proposes a hypothesis that aerobic exercise inhibits the progression of diabetic angiopathy via regulating the expression of lncRNA/ miR-492/resistin pathway, and then improving the vascular endothelial IR, relieving the endothelial injury. In the present study, IR rats were intervened with an 6-week swimming training program. After the training program, lncRNA chip was adopted to screen the specific lncRNA which regulates miR-492/resistin,the relationship between the target lncRNA and miR-492 as well as its downstream signal pathway would be verified by loss of function or over-expression research. This study is to seek the basis for exercise improving IR, preventing and treating DM as well as its vascular complications.

IR导致的内皮损伤是T2DM大血管病变的基础。已证实运动可改善IR，但机理不明。近年来，一种全新的非编码RNA(ncRNA)-ncRNA互作式网络，即lncRNA调控miRNA表达的模式在多种疾病中的作用已成为当前研究的热点。前期研究发现，miR-492负向调控resistin可能是游泳改善ApoE-/-小鼠主动脉内皮IR，减轻内皮损伤的重要机制。在此基础上，课题组提出假说：有氧运动是否通过调节lncRNA表达，进一步调节miR-492/resistin通路，从而改善血管内皮IR，减轻内皮损伤，抑制DM大血管病变。本研究拟对IR大鼠进行游泳训练，采用lncRNA芯片筛选运动改善血管内皮IR过程中调控miR-492/resistin表达的上游lncRNA, 并通过功能缺失或过表达研究阐明目标lncRNA与miR-492的调控关系及下游信号通路。该研究将为运动防治DM大血管病变提供依据。

IR导致的内皮损伤是T2DM大血管病变的基础。已证实运动可改善IR，但机理不明。lncRNA调控miRNA表达在多种疾病中的作用已成为研究的热点。该项目成功构建了胰岛素抵抗动物和细胞模型，采用lncRNA芯片结合生物信息学分析，筛选运动改善主动脉内皮IR过程中调控/resistin表达的上游lncRNA及miRNA, 并通过临床试验、功能缺失和过表达研究阐明目标lncRNA、miRNA与resistin的调控关系及下游信号通路。芯片结果提示，lnc Malat1可能是运动改善主动脉内皮IR过程中resistin的上游调控因子。生信分析提示miR-382-3p可调控resistin，且与Matat1具有结合位点。双荧光素酶、RIP结果显示Matat1通过竞争性吸附miR-382-3p促进resistin表达。挽救实验证实Malat1通过抑制miR-382-3p表达，促进 resistin表达，促进主动脉内皮IR形成。研究发现，Malat1在T2DM中高表达，且与HOMA-IR具有相关性；运动通过下调Malat1表达，进而上调miR-382-3p改善血管内皮IR。沉默Malat1使细胞葡萄糖摄入能力增加，细胞迁移能力降低，NO表达增加，AngⅡ表达降低，TNF-α、IL-6、sICAM-1、sVACM-1表达减少，ET-1、p-IRS/IRS-1表达降低，p-Akt/Akt表达增加。结果提示，游泳运动通过下调Malat1表达，进而上调miR-382-3p，抑制resistin表达改善血管内皮IR，减少内皮损伤。