Screening and bioinformatics analysis of differentially expressed miRNAs induced by hypoxia preconditioning in rat cardiomyocytes / 中国药理学通报

ABSTRACT

Aim To screen the differentially expressed microRNAs ( miRNAs ) induced by hypoxia precondi-tioning ( HPC ) in adult rat cardiomyocytes, and pre-dict miRNAs-regulated target genes and their func-tions. Methods Cardiomyocytes were isolated from a-dult rat ventricular myocardium and cultured ( in vitro) . The cells were divided into 2 groups control group ( CON ) and hypoxia preconditioning group ( HPC) . The cardiomyocytes in HPC group were sub-jected to 10 min hypoxia followed by 30 min reoxygen-ation, while the cells in CON group were cultured un-der normal condition. After that, total RNA was ex-tracted and then subjected to miRNA microarray to screen differentially expressed miRNAs. The microar-ray results were further validated by quantitative RT-PCR ( qRT-PCR ) . Bioinformatics analysis was per-formed to predict the miRNAs-regulated target genes and analyze the enriched gene ontology ( GO) and sig-naling pathway ( Pathway) . Results HPC caused sig-nificant changes in miRNAs expression in cardiomyo-cytes as compared to CON group. A total of 12 miR-NAs were up-regulated and 14 miRNAs were down-reg-ulated ( P 500 were selected for further bioinformatics analysis. The expression of miR-133b-5p, miR-664-1-5p and miR-6216 detected by qRT-PCR exhibited the similar patterns of up or down regulation to those shown in mi-croarray results. Bioinformatics analysis revealed that miRNAs-regulated target genes were significantly en-riched in 27 GOs and 6 signal pathways. Conclusion The expression profile of miRNAs in rat cardiomyo-cytes is significantly affected by HPC. These differenti-ally expressed miRNAs might participate in HPC-in-duced cardioprotection by regulating their target genes in rat cardiomyocytes.