Mysm1 epigenetically regulates the immunomodulatory function of adipose-derived stem cells in part by targeting miR-150.

Adipose-derived stem cells (ASCs) are highly attractive for cell-based therapies in tissue repair and regeneration because they have multilineage differentiation capacity and are immunosuppressive. However, the detailed epigenetic mechanisms of their immunoregulatory capacity are not fully defined. In this study, we found that Mysm1 was induced in ASCs treated with inflammatory cytokines. Adipose-derived stem cells with Mysm1 knockdown exhibited attenuated immunosuppressive capacity, evidenced by less inhibition of T cell proliferation, more pro-inflammatory factor secretion and less nitric oxide (NO) production in vitro. Mysm1-deficient ASCs exacerbated inflammatory bowel diseases but inhibited tumour growth in vivo. Mysm1-deficient ASCs also showed depressed miR-150 expression. When transduced with Mysm1 overexpression lentivirus, ASCs exhibited enhanced miR-150 expression. Furthermore, Mysm1-deficient cells transduced with lentivirus containing miR-150 mimics produced less pro-inflammatory factors and more NO. Our study reveals a new role of Mysm1 in regulating the immunomodulatory activities of ASCs by targeting miR-150. These novel insights into the mechanisms through which ASCs regulate immune reactions may lead to better clinical utility of these cells.