Cloning And Primary Functional Research Of Mir126 In Human Heart And Endothelial Cells

Objectives:To clone and discover miRNAs highly expressed in human cardiovascular system, find and analysis their expression profile and target genes, explore the probable pathophysiological process these microRNAs may be involved in. Methods: MiRNAs libraries of human heart and endothelial cells were constructed, and the expression profile of miRNAs were detected using Northern Blot and Real-Time PCR. To speculate and analysis the biogenesis and target genes of the newly-found miRNA, bioinformatics and molecular biologic procedure were performed. Microarray was used to discover the genes which may be regulated by the miRNA over-expressed in Hela. Results: Hundreds of miRNAs expressed in human cardiovascular system were cloned and a new miRNA---mir-126 was, for the first time, discovered in human tissues and cells. Furthermore, mir-126 was verified highly expressed in endothelial cells and cardiomyocytes. Mir-126 was located in the 7th intron of egfl7 and can be formed through the splicing of its pre-mRNA. VEGF was a mir-126 target and the expression of mir-126 was downregulated in breast cancer tissues. In addition, mir-126 could downregulate the expression of AKT2 while could activate the expression of TNFAIP3 and CXCL11. Conclusions: Mir-126 is a highly expressed miRNA in human cardiovascular system and may play important roles in the regulation of cardiac metabolism and angiogenesis.