Allogeneic adipose-derived stem cells promote survival of fat grafts in immunocompetent diabetic rats.

Abstract

Autologous adipose-derived stem cells (ADSCs) can protect fat grafts in cell-assisted lipotransfer (CAL). However, diabetes alters the intrinsic properties of ADSCs and impairs their function so that they lack these protective effects. We investigate whether allogeneic ADSCs from healthy donors could protect fat grafts in immunocompetent diabetic rats. Syngeniec adipose tissues and ADSCs were derived from diabetic Lewis (LEW) rats, whereas allogeneic ADSCs were from healthy brown-Norway rats. A grafted mixture containing 0.7ml granule fat and 0.3ml 6 × 10(6) allogeneic/syngeneic ADSCs was injected subcutaneously on the skulls of diabetic LEW rats. Fat samples were harvested to evaluate the levels of injury and vascularization as shown by perilipin A, CD34 and VEGF at 14days. The immune response was evaluated with a lymphocytotoxicity test and the CD4/CD8 ratio in peripheral blood at 14days. The volume retention of fat grafts was measured at 3months. Healthy allogeneic ADSCs increased the expression levels of perilipin A, CD34 and VEGF at 14days. The volume retention of fat grafts was improved by allogeneic ADSCs at 3months. ADSCs were demonstrated to have low immunogenicity by the lymphocyte proliferation test and immunophenotype including MHC and co-stimulatory markers. The lymphocytotoxicity test and CD4/CD8 ratio indicated no obvious immune response elicited by allogeneic ADSCs. Thus, healthy allogeneic ADSCs can promote the survival of fat grafts in this immunocompetent diabetic rat model, with little or no obvious immune rejection.