ciRs-MFACR/miR-30a相互作用调控GATA-5在衰老心肌缺血后处理自噬水平降低中的机制研究

衰老心肌自噬水平降低是缺血后处理(IPO)抗缺血/再灌注(I/R)损伤的重要机制。ciRs和miRs在调节方式上具有相似性，且ciRs富含miRs结合位点，二者可相互作用抵消对靶基因的抑制，但机制未清。GATA-5能特异性结合靶基因高度保守的DNA序列，是调控心肌功能的关键基因，故推测：ciRs和miRs相互作用介导GATA-5引起自噬水平降低是衰老心肌IPO抗I/R损伤的重要机制。为了验证该假说，筛选并确定ciRs-MFACR和miR-30a是衰老心肌IPO自噬水平下降的特异性ciRs和miRs；采用免疫共沉淀和生物素特异性探针分别沉淀或下拉与两者结合的复合物，明确两者相互作用的机制；利用GATA-5抗体进行RNA免疫共沉淀及质谱分析，确定GATA-5是ciRs-MFACR功能性靶基因，旨在揭示两者相互作用在衰老心肌自噬水平降低的机制，探寻关键靶点，为衰老心肌抗I/R损伤提供潜在药靶。

The decrease of autophagy level in aged myocardium is an important mechanism of ischemic post-conditioning (IPO) against I/R injury. Circular RNA (ciRs) and miRNA (miRs) are similar in regulation mode and ciRs is rich in miRNA binding sites, so the interaction between ciRs and miRs can counteract the inhibition of the target gene, but the mechanism is unclear. GATA-5 can specifically combine the highly conserved DNA sequence of the target gene, which is the key gene for regulating the function of myocardium. Therefore, it is speculated that the interaction between ciRs and miRs mediates GATA-5-induced the autophagy level decreased, which is an important mechanism for IPO against I/R in aged myocardium. To verify this hypothesis, ciRs-MFACR and miR-30a were screened and identified as specific ciRs and miRs of decreased autophagy level of IPO in aged myocardium. By using immune coprecipitation and biotin specific probe respectively precipitate or pull-down the complex that combinated with ciRs-MFACR and miR-30a, which to clarify the mechanism of interaction between them; Using GATA-5 antibody to carry out immune RNA coprecipitation and mass spectrometry analysis, which to confirm that GATA-5 is a functional target gene of ciRs-MFACR and to reveal the mechanism of the interaction between ciRs-MFACR and miR-30a in decreased autophagy levels of IPO in aged myocardium. Exploring key targets and potential drug target for aging myocardium against I/R injury.