Abstract
The mechanisms underlying atherosclerosis (AS) that seriously affect human health, such as those involved in endothelial cell injury and monocyte/macrophage aggregation and infiltration, have not been fully elucidated. To investigate these processes, we established human umbilical vein endothelial cells (HUVECs) injured by oxidized low-density lipoprotein (ox-LDL) to mimic AS in vitro. Apolipoprotein E knockout (ApoE-/-) C57BL/6 mice were fed with a high-cholesterol diet to establish an AS model in vivo. We detected HUVEC apoptosis, and apoptosis-related proteins by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide and lactate dehydrogenase, flow cytometry, and Western blot assays, respectively, and we observed monocytes (THP-1 cells) adhering to HUVECs. Furthermore, miR-147a and its downstream target gene ZEB2 (zinc finger E-box binding homeobox 2) were predicted by bioinformatics analysis to be involved in AS, and their correlation was confirmed by several experiments. We determined the localization of miR-147a and ZEB2 within macrophages of AS mice by in situ hybridization and immunofluorescence. Atherosclerotic plaques in whole aortas were detected by histology observation. miR-147a attenuated adherence of monocytes to HUVECs and the upregulation of mononuclear chemotactic adhesion receptors in THP-1 cells induced by ox-LDL-injured HUVEC supernatants through directly downregulating ZEB2 levels. Moreover, miR-147a influenced M1/M2 macrophage polarization from THP-1 cells and the roles of their supernatants (THP-1 cells) in HUVEC apoptosis. miR-147a targeted ZEB2 to impact lipid accumulation and atherosclerotic plaque formation through regulating M1/M2 polarization and macrophage adhesion in AS mice. In summary, miR-147a attenuates ox-LDL-induced adherence of monocytes to HUVECs and modulates atherosclerotic plaque formation and stability through targeting ZEB2 during AS.