TRPC1在糖尿病内皮祖细胞功能障碍中的作用及其机制研究

Endothelial progenitor cells (EPC) was applied to treatment of impaired endothelial regeneration because of its strong proliferation potential and the characteristics of differentiation to vascular endothelial cell.The functions of endothelial progenitor cells (EPC) in diabetic patients are severely injured and the specific mechanism has not yet fully been elucidated. Based on our previous study results that diabetes mellitus impaired EPC proliferation and migration, this project aims to further study the change of EPC function in vitro and angiogenesis ability in vivo under high glucose treatment. To investigate the underlying mechanisms, we aims to observe the changes of TRPC1、AMPK and ER stress.pathway in EPC under high glucose, and also observe the function changes of EPC overexpressed with TRPC1 after pretreating with AMPK and ER stress inhibitor.Then, we will observe whether overexpressd TRPC1 can improve the capability of EPC in vivo angiogenesis and ischemic myocardial repair in the model of diabetic rats Matrigel plug and myocardial infarction. This study will elucidate the role and mechanism of TRPC1 in diabetic EPC dysfunction and the downstream signaling molecules, providing new clues for seeking the target of therapy of diabetic.cardiovascular diseases.

内皮祖细胞(EPC)因其具有的强大增殖潜能及向血管内皮细胞分化的特性而被应用于受损血管内皮的再生治疗。但EPC功能在糖尿病患者中严重受损且其具体机制尚未完全阐明。本项目拟在前期的糖尿病EPC增殖、迁移功能变化的基础上，进一步观察体外高糖培养EPC的功能及其在体血管新生能力的变化情况。为明确其机制，拟观察高糖培养EPC内TRPC1、AMPK及内质网（ER）应激通路的改变，并通过抑制AMPK、ER应激，观察上调TRPC1对EPC功能的影响。继而,在糖尿病大鼠Matrigel plug模型与心肌梗死模型中分别观察上调TRPC1能否提高EPC在体血管新生与缺血心肌修复能力。本研究将阐明TRPC1在糖尿病EPC功能障碍中的作用及其下游信号分子机制，为寻找糖尿病心血管病的治疗靶点提供了新的线索和思路。

糖尿病患者冠心病发病危险性较同龄正常人群升高了3～4 倍，糖尿病患者血管内皮细胞凋亡数量增加、功能紊乱被认为是导致冠心病高发的核心环节。内皮祖细胞(EPC)因其具有的强大增殖潜能及向血管内皮细胞分化的特性而被应用于受损血管内皮的再生治疗。但EPC功能在糖尿病患者中严重受损且其具体机制尚未完全阐明。本项目在前期的糖尿病EPC功能受损的基础上，进一步研究发现体外高糖培养导致TRPC1表达水平降低，以及EPC的功能损伤，过表达TRPC1显著改善高糖培养导致的EPC功能损伤。接下来研究结果显示过表达TRPC1逆转了高糖导致的AMPK活性降低及内质网（ER）应激水平增强，在过表达TRPC1的基础上抑制AMPK活性，EPC的功能损伤改善水平显著低于仅过表达TRPC1组,在过表达TRPC1的基础上抑制ER应激，进一步地显著性改善了EPC的功能损伤，这提示AMPK及ER应激通路参与TRPC1介导的高糖培养所致EPC功能损伤。最后, 在糖尿病大鼠Matrigel plug与心肌梗死动物实验中发现上调TRPC1表达水平可显著提高糖尿病EPC在体血管新生与缺血心肌修复能力。本项目研究结果提示TRPC1是调控糖尿病EPC功能障碍的关键因子，为治疗糖尿病心血管病提供了潜在靶点。