The up-regulation of ANXA1 by FTO-dependent demethylation alleviates NLRP3-mediated pyroptosis and inflammation in myocardial ischemia–reperfusion injury

Background Ischemia–reperfusion (I/R) injury is a severe disorder during revascularization therapy against acute myocardial infarction. Objective Our study aims to investigate the role and regulation mechanism of Annexin A1 (ANXA1) against I/R injury. Results Western blotting analysis showed that ANXA1 expression in rat cardiomyocytes (H9C2 cells) was notably decreased by oxygen–glucose deprivation/reperfusion (OGD/R) treatment. Meanwhile, the NLRP3 inflammasome activation accompanied by pyroptosis and inflammation was observed in H9c2 cells under OGD/R induction. Besides, overexpression or knockdown of ANXA1 dramatically inhibited or aggravated NLRP3-mediated pyroptosis and inflammation. Further investigations found that the m 6 A level of ANXA1 was upregulated by OGD/R, thus leading to decreased mRNA stability in H9C2 cells. FTO, a N6-methyladenosine (m 6 A) “eraser”, was downregulated in H9C2 cells by OGD/R and shown to increase the ANXA1 protein expression by demethylating mRNA in H9c2 cells under OGD/R induction. Moreover, knockdown FTO reversed the protection of ANXA1 against NLRP3-mediated pyroptosis and inflammation in OGD/R-induced H9C2 cells. Conclusion ANXA1 protects cardiomyocytes against I/R injury by alleviating NLRP3-mediated pyroptosis and inflammation via FTO-mediate demethylation. These findings innovatively suggest the therapeutic potential of ANXA1 for myocardial I/R injury.