Drp1介导的线粒体分裂异常参与脓毒症心肌损伤机制的研究

项目名称： Drp1介导的线粒体分裂异常参与脓毒症心肌损伤机制的研究

项目编号： No.81471837

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 医药、卫生

项目作者： 陈莹莹

作者单位： 浙江大学

项目金额： 74万元

中文摘要： 线粒体功能障碍是导致脓毒症心肌损害的主要原因。最新研究表明，线粒体融合和分裂的动态平衡是维持心肌线粒体正常生理功能的关键。我们前期的预实验发现，动力相关蛋白1（dynamin-related peptide 1，Drpl）介导的线粒体分裂增加可能是导致脓毒症心肌细胞凋亡和功能障碍的主要原因，但具体分子机制尚不明了。本课题将采用DNA定点突变的方法，确定哪些磷酸化位点是导致Drp1蛋白线粒体剪切活性改变，引发脓毒症心肌细胞凋亡的关键，并探讨钙调磷酸酶在Drp1蛋白去磷酸化中的地位。进一步利用分子生物学及免疫共沉淀等实验方法，筛选并鉴定与Drp1相互作用的凋亡蛋白，阐明Drp1蛋白介导的线粒体分裂增加是否通过Bax依赖性机制发挥促凋亡作用。通过对本课题的研究将阐明Drp1介导的线粒体分裂异常参与脓毒血症心肌损伤分子机制，从而为临床上寻求对抗脓毒症心肌损伤的有效作用靶点提供新的思路和理论依据。

中文关键词： 脓毒症；细胞凋亡；线粒体分裂；动力相关蛋白1

英文摘要： Myocardial injury is a major contributor to mortality and morbidity in patients with sepsis. Mitochondrial dysfunction is one of the major molecular mechanisms that may be involved in myocardial dysfunction during sepsis. The new findings have altered the perception that cardiac mitochondria are static. Mitochondrial fusion and fission in cardiomyocytes are detected as that in non-cardiac systems. The dynamic equilibrium between mitochondrial fusion/fission is necessary to maintain mitochondrial integrity and normal fuction in myocardium. Our primarily study showed that increase in the dynamin-related peptide 1 (Drp1)-mediated mitochondrial fission might be the key cause which led to sepsis-induced myocardial dysfunction. However the exact mechanism is still unknown. The aims of present study are to identify which of the critical phosphorylation sites of Drp1 are responsible for its cleavage activity during mitochondrial fission, and also actively participate in apoptosis induction, by using site directed mutagenesis method; to investigate the role of calcineurin in the dephosphorylation of Drp1 during sepsis; to explore which of the pro-apoptosis proteins are the key effectors/targets of Drp1 in this sepsis model by using pharmacological method, molecular biological method and co-immunoprecipitation assay; to elucidate whether the increase in Drp1-medicated mitochondrial fission participates in apoptosis induction during sepsis through Bax dependent manner. This study may help to elucidate the molecular mechanism and role of Drp1-mediated mitochondrial fission in sepsis-induced myocardical apoptosis and dysfunction in. The results of this study will provide new ideas and theoretical basis for the new target that preventment of septic cardiomyopathy.

英文关键词： sepsis;cell apoptosis;mitochondrial fission;dynamin-related peptide 1