银杏内酯B保护血小板线粒体损伤的机制及PPAR-γ/PHB信号通路调控研究

Platelet activation in patients with hypertension comorbidity with diabetes mellitus is common and prone to ischemic cardiocerebrovascular events. Ginkgo biloba extract is often used for adjunctive treatment of this diseases. It is well known that damage or functional abnormality of mitochondria play a key role during platelet activation. Our previous studies found activated PPAR-γ can mitigate effects of high hydrostatic pressure on platelet activation, and PPAR-γ, PHB and miR27 were involved in the regulation of mitochondrial function of adipose-derived stem cells. But the mechanism of its regulation of mitochondrial dysfunction in platelets is not clear. The study use bioinformatics analysis, high sugar/high hydrostatic pressure mitochondrial disorders of platelet and platelet activation as the main line, to present a scientific hypothesis: "PPAR-γ/PHB/miR27 were involved in the regulation of platelet mitochondria dysfunction in diabetes/high blood pressure state, this pathway may be involved in the antiplatelet effect of Ginkgolide b." Through clinical cases, diabetic mouse model and high sugar/high hydrostatic pressure in vitro culture model of platelets, raised or inhibited PPAR gamma, PHB, miR27 with a variety of molecular biology techniques, the regulatory mechanism of platelet mitochondria function and structure will be studied, and effects of ginkgolide b intervention on them. These will provide the basis to clarify platelet mechanism of Ginkgo biloba.

高血压合并糖尿病患者血小板常异常激活，并易发缺血性心脑血管事件。银杏提取物常被用于缺血性心脑血管疾病的辅助治疗。已知线粒体损伤或功能异常是血小板激活的重要启动因素。前期研究发现①激活PPARγ可减轻高静水压对血小板的激活作用；②PPARγ、PHB及miR27参与调节脂肪干细胞线粒体的功能，但其对血小板线粒体功能紊乱的调控机制不清楚。本研究通过生物信息学分析，以高糖/高压条件下血小板线粒体功能紊乱-血小板激活为主线，提出科学假设：“PPARγ/PHB/miR27参与调控糖尿病/高血压状态下血小板线粒体功能紊乱，该通路可能参与银杏内酯B的抗血小板治疗作用”。通过对临床病例、糖尿病小鼠模型和体外高糖/高静水压状态培养血小板模型，利用上调或者下调PPARγ、PHB、miR27各种分子生物技术，系统研究其对血小板线粒体功能和结构的调控机制，及银杏内酯B干预对其影响，为阐明银杏的抗血小板机制提供依据。

糖尿病患者通常存在血小板异常激活，并易发缺血性心脑血管事件。银杏提取物常被用于缺血性心脑血管疾病的辅助治疗。已知线粒体损伤或功能异常是血小板激活的重要启动因素。本课题以“血小板线粒体功能紊乱-血小板激活”为研究主线，提出拟解决的关键科学问题是“miR27/PHB对糖尿病血小板线粒体功能调节作用及机制，深入探讨这一机制是否参与了银杏内酯B的抗血小板作用”。采用临床病例、糖尿病大鼠模型和体外培养血小板，利用上调或者下调miR27/PHB各种分子生物技术，系统研究发现：1）糖尿病患者血小板基础自噬强于非糖尿病患者，且PHB参与此过程；同时在离体状态下，H2O2导致的氧化应激可刺激血小板发生自噬，并促进血小板活化，miR-27a参与其中；2）在氧化应激刺激下，miR-27a可能通过降低PHB蛋白表达，抑制血小板自噬，从而抑制血小板的活化；3）抗增殖蛋白2（PHB2）作为线粒体内膜受体，参与了血小板线粒体自噬，并可能通过抑制血小板活化基因的表达，进而抑制血小板的活化；4）银杏内酯B可能通过miR-27a/PHB介导的血小板自噬保降低H2O2刺激下的血小板激活和聚集，对血小板功能具有保护作用；同时在体动物实验也证实银杏内酯B对血小板有一定的保护作用，或可成为治疗血栓性疾病的药物。本研究发现银杏内酯B可通过miR-27/PHB信号通路抑制血小板活化干预糖尿病血小板线粒体功能，为临床抗血小板治疗提供了新的靶点和治疗手段。