Vitamin A Supplementation Reduces IL ‐17 and ROR c Gene Expression in Atherosclerotic Patients

Vitamin A is a potential mediator of T helper cells in atherosclerosis. The purpose of this study was to evaluate the effect of vitamin A supplementation on expression of Th17 cells‐related IL ‐17 and ROR c genes in atherosclerotic patients. Thirty one atherosclerotic patients and 15 healthy controls were studied for 4 months. Atherosclerotic patients were randomly divided into vitamin A or placebo groups. Healthy controls and patients in vitamin A group received 25,000 IU retinyl palmitate per day. Peripheral blood mononuclear cells were isolated, cultured and divided into three groups including fresh cells, phytohemagglutinin ( PHA )‐activated T cells and ox‐ LDL ‐activated T cells. Gene expressions of T cells were studied by real‐time PCR . In atherosclerotic patients, vitamin A supplementation resulted in significant decrease in IL ‐17 gene expression by 0.63‐fold in fresh cell, 0.82‐fold in PHA ‐activated cells and 0.65‐fold in ox‐ LDL ‐activated cells ( P  < 0.05 for all). ROR c gene expression in fresh cells as well as ox‐ LDL ‐activated cells decreased significantly after vitamin A supplementation in atherosclerotic patients ( P  = 0.0001 for both). In PHA ‐activated cells, vitamin A supplementation significantly decreased ROR c gene in both atherosclerotic patients and healthy subjects by 0.87‐fold and 0.72, respectively, while in placebo group, the ROR c gene expression significantly increased by 1.17‐fold ( P  < 0.05 for all). Findings of this study suggest that vitamin A supplementation may be an effective approach to slow progression of atherosclerosis.