膜联蛋白A1三肽在糖尿病心肌缺血-再灌注损伤中的保护作用及线粒体机制研究

糖尿病患者心肌缺血-再灌注损伤（MIRI）发病率及致死率高，且缺乏有效的防治手段。前期证实膜联蛋白（Annexin）A1短肽（膜联三肽）可通过线粒体内去乙酰化酶3（Sirt3）明显减轻MIRI，因此提出膜联三肽通过调控线粒体稳态减轻糖尿病MIRI这一假说。本研究拟建立糖尿病大鼠心脏在体、离体、成年鼠心肌细胞缺血-再灌注模型，并于再灌注即刻给予膜联三肽，对比观察糖尿病MIRI情况下，膜联三肽对①近远期心功能、心肌损伤标志物、心梗程度、心肌组织微结构；②心肌细胞活力、细胞內钙、ATP含量；③线粒体结构、膜电位、mPTP开放水平、呼吸功能、Cyt c溢出情况；④Sirt3表达量、线粒体ATP敏感性钾通道（mitoKATP）的作用及氧化应激、线粒体凋亡途径相关指标的影响。本项目将进一步阐明膜联三肽对糖尿病心肌的保护作用，也将有助于开发以膜联蛋白、Sirt3、mitoKATP为靶点的药物。

The morbidity and mortality of myocardial ischemia-reperfusion injury (MIRI) are much higher in diabetic patients and the efficient prevention and cure are limited. We have reported that Annexin A1 short peptide (ANXA1sp) can efficiently attenuate MIRI via increasing the expression and the activity of Sirtuin 3 (Sirt3) which locates in mitochondria. Based on our previous findings, we hypothesize that ANXA1sp relieves MIRI by stabilizing the mitochondria homeostasis. The in vivo and ex vivo diabetic MIRI model and the in vitro adult diabetic cardiomyocyte ischemia-reperfusion injury model will be set, the ANXA1sp will be given at the onset of reperfusion. Then, the effects of ANXA1sp under the diabetic MIRI circumstance on 1) the short- and long-term cardiac function, biomarkers of heart ischemic injury, the infarct area and the ultrastructural changes of myocardium; 2) the cardiomyocyte viability, intracellular free calcium and ATP content; 3) the mitochondria structure, mitochondrial membrane potential (ΔΨm), the opening level of mitochondrial permeablity transition pore (mPTP), the respiratory function and the flowout of Cyt c; 4) the expression of Sirt3, the roles of mitochondrial ATP sensitive potassium channel (mitoKATP), the oxidative stress biomarkers and mitochondrial related apoptosis biomarkers will be evaluated. These studies will not only reveal the effects of ANXA1sp on MIRI in diabetic rats, but also help to develop drugs that targeting ANXA1sp, Sirt3 or mitoKATP.