[Differential expression and implication of m6A methylation in mice with experimental myocardial infarction]

Objective: To define differentially expressed N6-adenylate methylation (m6A) genes in the myocardial tissue of mice with myocardial infarction (MI) and explore its potential impact on the pathological process of MI. Methods: The random number table method was used to divide the eighteen SPF C57BL/6J male mice aged from 8 to 10 weeks into MI group (MI group, n=9) and control group (control group, n=9). Modified m6A genes from the myocardial tissue were detected via methylated RNA immunoprecipitation with the next generation sequencing (MeRIP-seq). We explored methylation modified characteristics, verified mRNA expression and m6A modified level by bioinformatics analysis, qPCR and MeRIP-qPCR. Results: The Heatmap revealed that 901 differentially modified m6A genes between MI and control group, of which 537 genes were upregulated, and 364 genes were downregulated. The principal component analysis affirmed that two groups could be distinguished significantly in terms of m6A gene modification. The characteristic sequence of m6A modification was GGACU and mainly concentrated in the coding sequence. According to the conjoint analysis with RNA-seq and MeRIP-seq, 119 genes expressed simultaneous m6A modification difference and mRNA expression difference. The Venn diagram exhibited the positive and negative correlation between m6A modification and mRNA expression. Besides, the GO enrichment analysis indicated that the genes with m6A differential modification in MI group were mainly involved in heart development and other processes. qPCR verified that Gbp6 was up-regulated, while Dnaja1 and Dnajb1 were down-regulated. MeRIP-qPCR revealed that the m6A modification level of Hspa1b was downregulated. Conclusion: Myocardial infarction induces differential modification of m6A in the mice model. In addition, the genes with m6A modification may be affected by methylation related enzymes, thus participating the pathogenesis of MI by regulating apoptosis and inflammation.