miR-34c在保护高糖诱导的VSMCs早衰并延缓糖尿病血管老化与钙化中的作用及机制

Arterial calcification is an important phenotype of vascular aging, and the crucial feature of diabetic macrovasculopathy, resulting in serious cardiovascular events and tough prophylaxis and treatment. The role and mechanisms of vascular smooth muscle cells (VSMCs) premature senescence involved in diabetic vascular aging and arterial calcification remain unknown. Our previous studies demonstrated for the first time that high-glucose could induce VSMCs premature senescence, proving the relevance between VSMCs premature senescence and diabetic macrovasculopathy. Then we screened out down-regulated miR-34c in aging and calcified renal artery of patient with diabetes, accompanied with up-regulation of mammalian target of rapamycin (mTOR) and enhanced expression of BMF (bcl-2 modify factor , the target of miR-34c) in the process of VSMCs premature senescence induced by high glucose, hence suggesting the involvement of miR-34c, mTOR and BMF in the process of vascular aging and calcification. Based on these results, we hypothesize that miR-34c may protect VSMCs from premature senescence induced by high glucose and may delay the process of diabetic vascular aging and calcification via BMF and mTOR signaling pathway. We will test this hypothesis both in vitro and in vivo, from both animal models and clinical patients. These studies would reveal a new regulatory mechanisms of diabetic vascular aging and calcification, provide a theoretical basis and a new insights into potential therapeutic targets against diabetes vascular aging and calcification.

大动脉钙化是血管老化的重要表型，也是糖尿病大血管并发症的重要特征，可导致严重心血管事件且防治困难。血管平滑肌细胞（VSMCs)早衰在糖尿病血管老化和钙化中的作用及机制不明。申请人的工作将VSMCs早衰与糖尿病大血管病变联系起来，首次发现:高糖可诱导VSMCs早衰；在糖尿病患者老化钙化肾动脉中筛选出miR-34c并发现其表达下调。预实验发现:在高糖诱导的VSMCs早衰模型中miR-34c下调，同时哺乳动物雷帕霉素靶蛋白(mTOR)及miR-34c靶基因BMF(bcl-2修饰因子）上调，提示miR-34c、mTOR及BMF可能参与血管老化及钙化。故提出假设：miR-34c可能通过BMF及mTOR信号保护高糖诱导的VSMCs早衰并延缓糖尿病血管老化及钙化。本项目通过细胞、动物及临床多层面验证假说，将揭示糖尿病性血管老化和钙化新的调节机制，为延缓糖尿病血管老化及钙化提供新的药物靶点和理论依据。

动脉钙化是血管老化的重要表型，也是糖尿病大血管并发症的重要特征，可导致严重心血管事件。血管平滑肌细胞（VSMCs）是构成血管壁的主要细胞，是血管钙化和老化的细胞生物学基础。本项目旨在深入研究miR-34c在保护高糖诱导的VSMCs早衰及延缓糖尿病血管老化及钙化的作用和机制，为探索动脉钙化和老化防治方法开辟新思路和新途径。在该项目的资助下，发现lncRNA-ES3与miR-34c-5p直接配对结合，增强miR-34c-5p的靶基因BMF的表达，并通过lncRNA-ES3/miR-34c-5p/BMF轴参与调节高糖诱导的VSMCs早衰和钙化，这不仅揭示了miR-34c-5p和lncRNA-ES3的新功能，而且将其拓展到对糖尿病患者高糖所致的VSMCs钙化和老化中非编码RNA的研究。本项目还首次发现，高糖环境下lncRNA-ES3与转录因子Bhlhe40结合后，通过抑制miR-95-5p、miR-6776-5p、miR-3620-5p和miR-4747-5p的表达参与调控VSMCs钙化/老化，进一步证实了lncRNA-ES3在血管钙化和老化过程中的作用。此外，我们发现高糖环境下血管内皮细胞（ECs）源性的外泌体携带versican蛋白及Notch3蛋白调节VSMCs 钙化/衰老；上述研究明确了外泌体作为细胞之间信息交流的桥梁在血管钙化和衰老中的作用和调控机制。本项目明确了血管老化的部分机制以及为延缓糖尿病性血管老化提供新思路和新靶点。