부산대학교 도서관

Epigenetic regulators, such as 5 methylcytosine (5mC), 5 hydroxymethylcytosine (5hmC), and miRNAs are important determinants of gene expressions, but the functions of these modifications in pathological conditions are not well defined, especially in heart failure. Introns can mediate gene expression through affecting transcription rate and transcript stability, however, the role of different epigenetic regulators to these mechanisms have not been explored yet. Mybpc3 deficient mice, which develop hypertrophic cardiomyopathy, would have an altered epigenetic landscape, leading to differential global gene expression, and regulation. We performed whole-genome methylome and hydroxymethylome analyses at single base-pair resolution, whole genome RNA sequencing, miRNA, and necessary bioinformatic analyses in cardiac tissues of 12-week old Mybpc3-/-mice and wild type controls. Mybpc3-/-mice had lower 5mC level (p < 0.001), but there was no overall difference in the 5hmC content (although knockout mice had lower 5hmC content in last exon, transcription termination site, and 3?-flanking regions). Interestingly, we observed that higher intronic 5hmC level was associated with higher gene expression, whereas, 5mC content in the 5?-flanking regions was associated with lower gene expression, regardless of the genotype. A total of 2291 genes were differentially expressed in Mybpc3-/-mice (FDR adjusted p < 0.1), of which 1241 were upregulated. Vgll2 and Aqp8 were among the top up-regulated genes, whereas, Cacng6 and Adcy8 were among the most downregulated genes in Mybpc3-/-mice. Pathway analysis showed that ?cardiac hypertrophy signalling? and ?role of NFAT in cardiac hypertrophy? were significantly enriched in Mybpc3-/-. ?RNA velocity? measurement shows pathogenic phenotype expression in knockout mice. We also observed upregulation of miR-199a-3p, miR-199b-3p, and miR-148a-3p, which may downregulate DNA methyl transferases, leading to lower 5-mC content in Mybpc3-/-mice. Loss of Mybpc3 is associated with significantly lower 5mC content and differential 5hmC distribution, which underlie alterations in global gene and miRNA expression, allowing us to identify novel drug targets to treat lethal condition of hypertrophic cardiomyopathy.