Vitamin E and hCG enhance the immunomodulatory properties of LPS-induced mesenchymal stem/stromal cells

Mesenchymal Stem/Stromal Cells (MSCs) have been applied to modulate various immune-mediated conditions. Prolonged culture of MSCs in vitro reduces their therapeutic efficacy. Pretreatment of the cells with some chemical agents during in vitro expansion could overcome this limitation. This study intended to determine whether pretreatment of adipose-derived MSCs (ASCs) with Human chorionic gonadotrophin (hCG), a glycoprotein hormone, and Vitamin E, an antioxidant, will improve their immunomodulatory ability. In this regard, ASCs were harvested from human processed lipoaspirate. LPS-induced ASCs were preconditioned with 1 mg of hCG and 600 µM of vitamin E for 24h. TSG-6, COX-2, IL-1β, and IL-6 were assessed at the mRNA level in preconditioned and control groups. ASCs were also co-cultured with peripheral blood mononuclear cells (PBMCs) in vitro to determine the functionality of these cells. Results showed that hCG and vitamin E significantly downregulate the pro-inflammatory COX-2, IL-1β, and IL-6 gene expression, while they did not significantly increase TSG-6 expression. Besides, the co-culturing of pretreated ASCs with PBMCs demonstrated that the amount of PBMCs in treated groups (with hCG and vitamin E) was significantly lower than in control groups. These findings revealed that the preconditioning of ASCs with hCG and vitamin E might enhance their immunoregulatory capacity.