Role of miR-106b-5p in the regulation of gene profiles in endothelial cells

Abstract

To evaluate the role of miR-106b-5p in the regulation of gene expression in endothelial cells. The Taqman low-density microRNAs (miRNAs) array (TLDA) was used to identify miRNA expression profiles in the plasma of patients with atherosclerotic coronary artery disease (CAD) (atherosclerosis group, n=9) and individuals without atherosclerotic CAD disease (control group, n=9). A weighed and undirected miRNA coexpression network analysis was performed to investigate the interactions among miRNAs in the two groups. MiR-106b-5p, whose coexpression pattern in atherosclerosis group was most different from that of control group, was further studied. Human umbilical vein endothelial cells (HUVEC) were transfected with miR-106b-5p mimic or negative control mimic, and Affymetrix GeneChip Human Transcriptome Array 2.0 was used to screen the differential gene expression profiles after transfection. And the signal transduction pathway of differential gene profiles was further analyzed in Kyoto Encyclopedia of Genes and Genomes (KEGG) signal pathway database. After parsing the whole KEGG database, all differentially expressed genes involved pathways were extracted, and the hypergeometric distribution was used to calculate the pathway enrichment. The coexpression pattern of the patients with atherosclerosis (140 nodes, 1 154 edges) differed from that of the non-atherosclerosis control group (140 nodes, 612 edges). The analysis of array data with significant analysis of microarray (SAM) identified 746 significantly deregulated genes (fold change ≥ 1.5 and false discovery rate < 0.01) altered by overexpression of miR-106b-5p with miR-106b-5p mimic in HUVEC. By calculating the pathway enrichment, we found that multiple signaling pathways enriched in differential gene profiles were closely related to the process of formation and rupture of atherosclerotic plaque, including phosphatidylinositol-3 kinase (PI3K)/ protein kinase B (PKB, also called Akt), mammalian target of rapamycin (mTOR), transforming growth factor-β (TGF-β), janus kinase / signal transducer and activator of transcription (Jak-STAT), tumor necrosis factor (TNF), toll like receptor (TLR) and hypoxia-inducible factor 1α (HIF-1α) and other signal pathways. The coexpression pattern of miRNAs in plasma of patients with atherosclerosis is more significantly changed than that of individuals without atherosclerotic disease. MiR-106b-5p, which shows the most significant difference between groups, targets multiple signal pathways in vascular endothelial cells, and might play an important role in the regulatory network of atherosclerotic gene expression.