免疫蛋白酶体β5i通过调节线粒体功能保护心肌缺血/再灌注损伤的分子机制研究

项目名称： 免疫蛋白酶体β5i通过调节线粒体功能保护心肌缺血/再灌注损伤的分子机制研究

项目编号： No.81500276

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 医药、卫生

项目作者： 于晓红

作者单位： 大连医科大学

项目金额： 18万元

中文摘要： 线粒体功能异常是心肌缺血/再灌注（I/R）损伤细胞凋亡的重要机制。蛋白酶体（包括组成型和免疫型）是调节细胞蛋白质降解的主要途径。其中组成型蛋白酶体参与凋亡相关蛋白降解及I/R心肌细胞凋亡已有报道。但是免疫型蛋白酶体特别是其β5i亚基在心肌I/R损伤中的作用及机制不清楚。我们预实验结果表明在I/R心肌细胞中β5i蛋白表达明显降低。而腺病毒转染过表达β5i可明显抑制I/R诱导的心肌细胞凋亡及其相关的凋亡蛋白表达，并显著改善线粒体分裂。本课题拟应用腺病毒过表达β5i或siRNA转染的乳鼠心肌细胞、心肌特异转β5i基因和敲除小鼠的I/R模型，以线粒体损伤（包括融合与分裂异常）、氧化应激、炎症反应及细胞凋亡为切入点进一步研究：①I/R损伤下调β5i表达的分子机制；②β5i在I/R诱导的心肌损伤中的作用；③β5i保护心肌I/R损伤的信号通路及分子机制。为心肌I/R损伤的防治提供新的研究方向和治疗靶点。

中文关键词： 心肌缺血/再灌注损伤；免疫蛋白酶体；免疫型β5；线粒体；凋亡

英文摘要： Mitochondrial dysfunction is an important mechanism of myocardial ischemia/ reperfusion (I/R)-induced apoptosis. Proteasome (including constitutive form and inducible form) is the main way of protein degradation regulation. Constitutive proteasome is involved in the degradation of apoptosis-related proteins and I/R-induced myocardial apoptosis. However, the role of immunoproteasome, particularly β5i subunit, and the molecular mechanisms in myocardial I/R injury is unclear. Our preliminary results indicate the expression of β5i protein is significantly reduced in the cardiac myocytes after I/R. However, the over expression of β5i by adenoviral transfection can significantly inhibit I/R-induced myocardial apoptosis, reduce the expression of apoptosis-related proteins and improves chondriokinesis. In the present study, using primary cultured myocardial cells transfected by adenovirus with β5i overexpression or knockdown β5i by siRNA, and mice I/R model with transgene or knockout of myocardial cell-specific β5i gene, taking mitochondrial injury (including abnormal fusion and fission), oxidative stress, inflammation and apoptosis into account, we aim to study: the molecular mechanisms through which I/R injury down regulate the expression of β5i; The role of β5i in I/R-induced myocardial injury and the underlying signal paths as well as molecular mechanisms. The objective is to provide novel research directions and therapeutic targets for the prevention and cure of I/R-induced myocardial injury.

英文关键词： myocardial ischemia-reperfusion ;immunoproteasome;β5i;Mitochondria;apoptosis