Immunomodulatory Properties of Adipose-Derived Stem Cells Treated with 5-Azacytydine and Resveratrol on Peripheral Blood Mononuclear Cells and Macrophages in Metabolic Syndrome Animals

Endocrine disorders, including equine metabolic syndrome (EMS), are a serious issue in veterinary medicine and horse breeding. Furthermore, EMS was shown to affect the cytophysiological properties of adipose-derived stem cells, reducing their therapeutic potential. However, it was shown that those cells can be rejuvenated while using a combination of two chemicals: 5-azacytydine (AZA) and resveratrol (RES). In the present study, we decided to evaluate the immunomodulatory properties of AZA/RES-treated adipose-derived stem cells (ASC) isolated from EMS horses (ASC_EMS). Thus, we co-cultured ASC with peripheral blood mononuclear cells (PBMC) and RAW264.7 macrophages. Most attention was placed on regulatory T lymphocytes (T_REG), as well as the messenger RNA (mRNA) and protein levels of several cytokines (tumor necrosis factor α (TNF-α), interleukin (IL)-6, IL-10, and IL-1β). Moreover, we also investigated the expression of genes related to auto- and mitophagy in both PBMCs and ASCs. PBMCs were obtained from healthy and EMS-suffering individuals and were co-cultured with ASCs that were isolated from healthy and EMS horses cultured in control conditions and with AZA/RES. We discovered that cells treated with AZA/RES increase the T_REG number while co-cultured with PBMCs. Moreover, the co-culture of PBMCs with AZA/RES-treated ASC_EMS induced mitophagy in PBMCs. Furthermore, ASC_EMS pre-treated with AZA/RES displayed anti-inflammatory properties, as decreased levels of TNF-α, nitric oxide (NO), and IL-6 were observed in those cells in comparison with their untreated counterparts in the co-culture with RAW264.7 macrophages. In summary, we demonstrated that ASC_EMS treated with AZA/RES displayed increased anti-inflammatory properties, and was able to regulate and activate the T_REG-related anti-inflammatory response.