The Effect Of Inflammatory Factors On MicroRNA-29a In Human Umbilical Vein Endothelial Cells

Background: Some previous studies have suggested inflammatory factors could mediate vascular endothelial functions, which may play a crucial role on atherosclerosis and coronary artery disease. Recently, microRNAs (miRNAs) have been found to regulate vascular construction and functions via targeting endothelial related targets. We focused on the new mechanism of inflammatory factors inducing endothelial dysfunction by screening miRNAs induced by inflammatory factors and identification of endothelial related targets.Methods: Human umbilical vein endothelial cells (HUVECs) were treated with recombinant protein tumor necrosis factor-alpha (TNF-α) and serum amyloid a (SAA), respectively. The change of miRNAs levels was examined by qRT-PCR and the change of protein levels of endothelial nitric oxide synthase (eNOS) was examined by Western Blot. The potential binding sites of miRNAs in eNOS were analyzed by bioinformatics software. The direct inhibition on eNOS was tested by luciferase reporter assay. On contrast, the change of miRNAs levels was examined after HUVECs were treated with Xiangdan Zhusheye, which might induce eNOS.Results: TNF-α and SAA induced the expression of miR-29a. Notably, there was a highly-conserved binding site in coding sequence (CDS) of eNOS for miR-29a. MiR-29a could directly bind to this region and sequentially inhibit eNOS expression. TNF-α and SAA inhibited the protein levels of eNOS. Xiangdan Zhusheye inhibited the expression of miR-29a in HUVECs while it induced eNOS and production of NO.Conclusion:TNF-α induced miR-29a, which post-transcriptionally inhibited eNOS by direct targeting to CDS of eNOS.