LncRNA-072211通过调控ERC1参与心肌缺血再灌注损伤

The prevention and treatment of myocardial ischemia-reperfusion injury is a challenging problem. To understand its mechanism and discover novel target is in urgent need. LncRNAs (long noncoding RNAs) are a new class of regulatory molecules and participate in the regulation of the disease process. The aim of this study is to investigate the effects and underlying mechanisms of lncRNA-072211 on cardiac ischemia-reperfusion injury. Our previous results showed that: 1) lncRNA-072211 was upregulated about 2-fold in myocardial ischemia and 1-fold in myocardial cell injury model; 2) overexpression of lncRNA-072211 aggravated cardiac function in the ischemic heart and myocardial cell apoptosis, and its silencing improved cardiac function and attenuated the apoptosis of myocardial cells; 3) mass spectrometry analyses of RNA pull down showed that lncRNA-072211 could be combined with ERC1 protein to form RNA- protein complex; 4) knockdown of ERC1 aggravated myocardial cell injury induced by H2O2. Therefore, we hypothesized that the interaction of lncRNA-072211 and ERC1 regulates myocardial ischemia-reperfusion injury through regulating apoptosis pathway, which elucidates the functions and molecular mechanism of lncRNA-072211 in ischemia-reperfusion injury.

心肌缺血再灌注损伤的防治是临床面临的难题和挑战，亟需加强其机制研究，发现新的干预靶点。lncRNA（long noncoding RNA）是一类重要新型调控分子，参与疾病过程的调控。本研究的目的是探讨lncRNA-072211对心脏缺血再灌注损伤的作用和机制。我们前期研究发现：1）lncRNA-072211在缺血心肌组织升高近2倍，在心肌细胞损伤模型中升高1倍；2）过表达lncRNA-072211加重缺血心脏功能和心肌细胞凋亡，而沉默其表达能够改善心脏功能和抑制心肌细胞凋亡；3）RNA pull down结合质谱分析发现lncRNA-072211与ERC1蛋白相结合形成RNA-蛋白复合体；4）敲减ERC1能够加重过氧化氢诱导的心肌细胞损伤。因此，我们假设：lncRNA-072211与ERC1结合通过细胞凋亡通路调控心肌缺血再灌注损伤，阐明其在缺血再灌注损伤中的作用与分子调控机制。

本项目采用小鼠冠状动脉结扎法建立心肌缺血再灌注和心肌纤维化模型，采用转基因小鼠、TUNEL染色、HE染色、RNA干扰、RNA/蛋白互作、实时定量PCR及基因报告等技术，从在体、离体及分子水平探讨了7个lncRNAs（long noncoding RNAs）和METTL3对心肌缺血再灌注损伤、心肌纤维化和糖尿病心肌病的调控作用及机制。重要发现：1. 发现lncRNA CIRKIL（lncRNA-072211）在心肌缺血再灌注损伤组织表达升高，通过与Ku70相互作用抑制Ku70的核转位和损害DNA双链的修复促进细胞凋亡。2. LncRNA H19作为miR-877-3p的竞争性内源RNA发挥作用，H19/miR-877-3p/Bcl-2通路参与了心肌缺血再灌注损伤过程中线粒体凋亡途径的调节，为心肌缺血再灌注损伤的调节机制提供了新的见解。3. LncRNA6395通过激活p53通路促进心肌细胞凋亡和缺血再灌注损伤。4. 发现lncRNA PCFL通过“吸附”miR-378，调控其下游GRB2的表达，发挥促心肌纤维化的作用。5. 过表达SAIL可抑制人、小鼠心脏成纤维细胞活性和胶原的合成，SAIL通过阻断SAFB和RNA聚合酶Ⅱ的结合，影响心肌纤维化进程。6. LncRNA H19、ACART和DACH1通过不同机制调控心肌细胞衰老、凋亡和糖尿病心肌病。7. RNA甲基化转移酶METTL3通过调控心脏成纤维细胞的激活调控心脏缺血性纤维化过程。.以上结果表明lncRNAs对心脏纤维化、心肌缺血、糖尿病心肌病等心脏疾病具有重要的调控作用，从不同层面揭示其调控多种心脏疾病的机制。以上研究发现扩展和加深了人们对lncRNAs在心脏疾病中的认识，对心脏疾病的基础研究与临床防治具有重要指导意义。本课题相关研究共发表SCI收录文章9篇。