关键词: 小鼠, 心肌组织, 生长发育, 转录组分析

Abstract: Postnatal cardiac function in mammals is closely associated with cardiomyocyte proliferation and hypertrophy. However, the molecular mechanisms regulating cardiomyocyte proliferation and hypertrophy have not yet been fully elucidated. Therefore, this study conducted phenotypic measurements and transcriptomic sequencing analysis on cardiac tissues from 7-day-old (P7) and 3-month-old (3m) female C57BL/6 mice to investigate the changes in cardiomyocytes during cardiac development and to identify key candidate genes influencing cardiac growth and development. In comparison to 7-days-old mice, 3-month-old mice exhibited a significant increase in heart weight (P<0.001) and the cross-sectional area of cardiomyocytes (P<0.001). Transcriptome sequencing identified 3,858 differentially expressed genes (DEGs), including 2,021 up-regulated and 1,837 down-regulated genes. Gene Ontology (GO) functional annotation analysis demonstrated that the differentially expressed genes were significantly enriched in biological processes including cell cycle, cell division, cardiac morphogenesis, organogenesis, and cellular proliferation. KEGG pathway analysis were significantly enriched in DNA replication, ECM-receptor interaction, the cell cycle, metabolic pathways, and other signaling pathways. Furthermore, key candidate genes associated with myocardial tissue growth and development in mice, including Hey2, Foxm1, Igf1, Fgfr2, Tbx20, Fgf1, Igf2 and other genes, were identified through screening. qRT-PCR validation results demonstrated that the expression trends of the 10 candidate genes related to cardiac development were consistent with the RNA-seq results, confirming the reliability of the sequencing data. The findings of this study provide new insights into the molecular mechanisms underlying the growth and development of mouse myocardial tissue.

Key words: mice, myocardial tissue, growth and development, RNA-seq