| Aims:Accumulating evidence suggest that numerous microRNAs (miRNAs) play important roles in cell proliferation, apoptosis, and differentiation, as well as various diseases that accompany inflammatory responses. Inflammation is known to be a major contributor to atherogenesis. Previous studies provide promising evidence in support of the role of miRNAs in cardiovascular disease. However, mechanistic data on these small molecules in AS are still missing. The associated functional role of miRNAs in animal models with minimal confounding factors in conjunction with human samples is also unclear. Hence, the present study was designed to shed light on these issues. The potential role of miRNA on atherosclerotic immuno-inflammatory responses is also investigated.Methods:The miRNA transcriptase was verified by TaqMan real-time polymerase chain reaction assay. Thoracic aorta samples were obtained from Apolipoprotein E knockout mice, and plasma samples were from coronary artery disease (CAD) patients. The functional role of miR-155in the atherosclerotic path physiological process and inflammatory effect was also observed in vivo and in vitro by chemically modified miR-155mimics and inhibitor (in vitro) and cholesterol conjugated cholesterol conjugated miR agomiR through tail vein injected once every2days for4weeks (in vivo). Firefly luciferase activity was determined using the dual-luciferase reporter assay system to confirm the target gene.Results:The miRNA transcriptase was verified by TaqMan real-time polymerase chain reaction assay. Thoracic aorta samples were obtained from Apolipoprotein E knockout mice, and plasma samples were from coronary artery disease (CAD) patients. The results showed that the miR-155level was the most significantly elevated both in AS mice and CAD patients relative to the normal control. We found that regulation of inflammatory cytokine secretion by miR-155in vitro and in vivo and also miR-155can prevent AS development and progression, mechanism study showed that miR-155inhibits the MAPK pathway in oxLDL-induced dendritic cell and ApoE knockdown mice. The reporter gene assay showed that compared with the pGL3-MAP3K10-3UTR plasmid cotransfected cells, there was a statistically significant increase and decrease in the activity of the cells cotransfected with the miR-155inhibitor and mimic, respectively, suggested that miR-155directly targets MAP3K10. Furthermore, the miR-155inhibitor-mediated effect on the inflammatory response was counteracted through the inhibition of MAP3K10by siMAP3K10on oxLDL-stimulated dendritic cell, therefore, the data suggested MAP3K10as a functional gene target involved in the miR-155-mediated inflammatory effect.Conclusions:miR-155contributes to the prevention of AS development and progression. It may also be involved in the posttranscriptional regulation of the inflammatory response and MAPK pathway by targeting mitogen-activated protein kinase kinase kinase10. |
