This study aims to investigate the role of targeting lncRNA myocardial infarction-associated transcript (MIAT) in protection against hypoxia/reoxygenation (H/R) injury in H9c2 cells in vitro and myocardial ischemia/reperfusion (I/R) injury in vivo by regulating expression of NF-kB and p53 upregulated modulator of apoptosis (PUMA). H9C2 cells were infected with lentivirus expressing the short-hairpin RNA direct against human MIAT gene (Lv-MIAT shRNA) or lentivirus expressing scrambled control (Lv-NC shRNA) or PUMA siRNA or p65 siRNA or their control siRNA respectively. Then the H9c2 cells were infected with Lv-shRNA to 2 hours of hypoxia (H) and 24 hour of reoxygenation (R). 100 ul of Lv-MIAT shRNA (1 × 10⁸ PFU) or Lv-NC shRNA was transfected into mouse hearts, then the hearts were subjected to I/R (1h/72 h). We discovered targeting MIAT remarkably enhanced H9c2 cell viability, decreased H/R-induced cell apoptosis and LDH leakage and significantly decreased I/R-induced myocardial infarct size, reduced myocardial apoptosis and enhanced the heart function. Targeting MIAT downregulated p65 nuclear translocation, NF-κB activity and anti-apoptotic protein cleaved-caspase-3, Bax, and upregulated anti-apoptotic protein Bcl-2 induced by H/R or I/R. Our study suggests that targeting MIAT may protect against H9c2 cardiomyoblasts H/R injury or myocardial I/R injury via inhibition of cell apoptosis, mediated by NF-κB and PUMA signal pathway.

这项研究旨在探讨针对lncRNA心肌梗死相关转录本（MIAT）在体外预防H9c2细胞缺氧/复氧（H / R）损伤和体内心肌缺血/再灌注（I / R）损伤中的作用NF-κB的表达和p53上调凋亡调节剂（PUMA）。H9C2细胞分别感染表达直接针对人MIAT基因的短发夹RNA的慢病毒（Lv-MIAT shRNA）或表达加扰对照的慢病毒（Lv-NC shRNA）或PUMA siRNA或p65 siRNA或它们的对照siRNA。然后将H9c2细胞用Lv-shRNA感染至缺氧2小时（H）和复氧24小时（R）。100ul Lv-MIAT shRNA（1×10 ⁸将PFU）或Lv-NC shRNA转染到小鼠心脏中，然后对心脏进行I / R（1h / 72 h）。我们发现靶向MIAT可以显着增强H9c2细胞的活力，降低H / R诱导的细胞凋亡和LDH渗漏，并显着降低I / R诱导的心肌梗死面积，减少心肌细胞凋亡并增强心脏功能。靶向MIAT可以下调H / R或I / R诱导的p65核易位，NF-κB活性和抗凋亡蛋白Caspase-3，Bax的表达，并上调抗凋亡蛋白Bcl-2的表达。我们的研究表明，靶向MIAT可能通过抑制由NF-κB和PUMA信号途径介导的细胞凋亡来预防H9c2心肌母细胞H / R损伤或心肌I / R损伤。