microRNA-338-3p promotes ox-LDL-induced endothelial cell injury through targeting BAMBI and activating TGF-β/Smad pathway.

microRNAs (miRNAs) have been revealed to participate in the pathological process of atherosclerosis (AS). However, the exact role of miR-338-3p, a target miRNA of BMP and activin membrane-bound inhibitor (BAMBI), and its possible molecular mechanism in AS remain unidentified. In this study, we found that BAMBI was significantly decreased, whereas miR-338-3p increased in patients with AS and oxidized low-density lipoprotein (ox-LDL)-induced HUVEC cells. Furthermore, overexpression of miR-338-3p significantly decreased cell viability and elevated cell apoptosis, whereas its inhibition significantly promoted cell viability and inhibited cell apoptosis in ox-LDL-induced HUVEC cells. Moreover, miR-338-3p overexpression increased TGF-β/Smad pathway activation in ox-LDL-induced HUVEC cells. A dual-luciferase reporter assay confirmed the direct interaction between miR-338-3p and the 3'-untranslated region of BAMBI messenger RNA. Furthermore, the suppression of BAMBI ameliorated the effect of miR-338-3p inhibition against ox-LDL-induced HUVEC cell injury. In conclusion, our study thus suggests that miR-338-3p promoted ox-LDL-induced HUVEC cell injury by targeting BAMBI and activating the TGF-β/Smad pathway, which may provide a novel and promising therapeutic target for AS.