HMGB1/RAGE/PINK1/Parkin介导线粒体自噬在糖尿病心肌缺血再灌注损伤中的作用机制

Myocardial ischemia-reperfusion injury (MIRI) is more common and severe during reperfusion therapy for diabetic patients with acute myocardial infarction than that of non-diabetic patients. However, the molecular mechanism remains elusive. Our previous experimental evidence indicates that HMGB1 increased in ischemic region of diabetic (db/db) mice, which is associated with mitochondrial damage and autophagy via the activation and regulation of the RAGE/PINK1/Parkin pathway. Therefore, we 1) in vivo establish the db/db mice model of MIRI, and in vitro do hypoxia/reoxygenation (H/R) injury in cardiomyocytes under hyperglycemic condition, and then we test its effects in vivo on the ischemia area and in vitro on indicators of cardiomyocytes ischemia-reperfusion injury (IRI); 2) investigate the underlying mechanism of mitochondrial autophagy in diabetic myocardial ischemia-reperfusion injury by siRNA, target gene overexpression with lentiviral vector, gene introduction, analysis of mitochondrial morphology, mitochondrial membrane potential and mitochondrial reactive oxygen species (ROS) detection; 3) elucidate molecular mechanisms of HMGB1/RAGE/PINK1/Parkin in diabetic myocardial ischemia-reperfusion injury. These basic studies aim to provide a theoretical basis for the prevention and treatment of MIRI in diabetes patients and develop mechanism-based effective therapeutic strategies.

合并糖尿病的急性心肌梗死患者再灌注治疗时更易发生心肌缺血再灌注损伤 (MIRI)，且损伤程度较非糖尿病者严重。然而，其作用机制尚未明确。我们前期研究表明，糖尿病(db/db)小鼠缺血区HMGB1表达升高，而HMGB1与线粒体损伤及自噬密切相关，其作用可能与调控RAGE/PINK1/Parkin通路有关。因此，本课题拟建立db/db小鼠的MIRI模型和体外高糖培养心肌细胞的缺氧-复氧损伤模型，以验证糖尿病时发生MIRI时缺血区面积及心肌细胞损伤程度，并利用siRNA、目的基因过表达慢病毒载体、基因导入、线粒体形态分析、线粒体膜电位和线粒体ROS 检测、激光共聚集等技术，检测线粒体自噬及自噬程度，以阐明HMGB1/RAGE/PINK1/Parkin介导线粒体损伤及自噬在糖尿病时MIRI 的分子机制，为糖尿病状态下MIRI的防治提供理论依据和寻找有效的干预靶点。

合并糖尿病的急性心肌梗死患者再灌注治疗时更易发生心肌缺血再灌注损伤 (MIRI)，且损伤程度较非糖尿病者严重。然而，其作用机制尚未明确。我们前期研究表明，糖尿病(db/db)小鼠缺血区HMGB1表达升高，而HMGB1与线粒体损伤及自噬密切相关，其作用可能与调控RAGE/PINK1/Parkin通路有关。因此，本课题建立db/db小鼠MIRI模型和体外高糖培养心肌细胞的缺氧-复氧损伤模型，以验证糖尿病时发生MIRI时缺血区面积及心肌细胞损伤程度，并利用siRNA、目的基因过表达慢病毒载体、基因导入、线粒体形态分析、线粒体膜电位和线粒体ROS检测、激光共聚集等技术，检测线粒体自噬及自噬程度。.我们的结果证实，糖尿病发生MIRI时HMGB1水平明显升高，HMGB1介导线粒体损伤及自噬异常而加重糖尿病MIRI，并明确了RAGE及PINK1/Parkin参与HMGB1介导线粒体自噬在糖尿病小鼠MIRI中的分子机制；抑制HMGB1能够减轻线粒体损伤和改善自噬，进而减轻糖尿病小鼠MIRI；冬凌草甲素（Oridonin）通过下调氧化应激和NLRP3炎症小体信号通路，抑制心肌免疫炎症反应，从而减轻MIRI。以上研究结果有望为糖尿病状态下MIRI的防治提供理论依据和干预靶点。