L-Arginine Ameliorates High-Fat Diet-Induced Atherosclerosis by Downregulating miR-221

OBJECTIVES: Atherosclerosis (AS) is a severe disease in which the inside of an artery narrows because of plaque formation, leading to endothelial injury in the patients. Although it has been found that endothelial nitric oxide synthase (eNOS), which produces a low concentration of NO, is necessary for endothelial function and integrity, the regulatory mechanisms of eNOS expression against the pathogenesis and development of AS are unclear. Evidence has indicated that diet supplementation with L-arginine could reduce the size of the endothelial injury lesions in AS patients. In addition, nonencoding microRNAs (miRNAs) were found to be a promising tool that regulates the expression of eNOS in human endothelial cells. DESIGN: The aim of this research was to explore the role of L-arginine in the development of AS and the mechanisms by which miR-221 influences the possible signaling pathways in endothelial cells during AS. RESULTS: The results suggested that L-arginine could prevent oxidized low-density lipoprotein-induced apoptosis in endothelial cells, which is associated with the downregulation of miR-221. Similar results were also observed in rat AS models. CONCLUSION: This research could provide potential therapies for the treatment of AS.