BACKGROUND: Syngeneic adipose-derived stem cells (ASCs) promote the survival of fat grafts. But it is unclear whether allogeneic ASCs have a similar protective effect. In this study, we investigated the protective effect of allogeneic ASCs in a fat graft model of immunocompetent rats. METHODS: Syngeneic and allogeneic ASCs were derived from Lewis (LEW) and Norway-Brown rats, respectively. Fifty-four LEW rats were divided into three groups. Each LEW rat was injected subcutaneously at two paravertebral spots with adipose granules premixed with DMEM (AFT group), syngeneic ASCs (SYNG group), or allogeneic ASCs (ALLG group). Fat grafts were harvested at 7 and 14 days to examine apoptosis rates and immunochemistry staining was performed for Perilipin A and CD34. At 3 months, fat graft volume retentions were measured. The proportion of regulatory T (Treg) cells and the ratio of CD4/CD8 cells in blood were analyzed at 7 days. RESULTS: Expression of Perilipin A and CD34 was higher in the ALLG group than the AFT group at 14 days (P < 0.05). The apoptosis rate in the ALLG group decreased in comparison with the AFT group at 7 and 14 days (P < 0.05). At 3 months, allogeneic ASCs increased fat graft volume retentions (P < 0.05). No difference was found in the proportion of Treg cells and CD4/CD8 cells ratio between groups. There were no statistically significant difference between ALLG and SYNG groups at all time points (P > 0.05). CONCLUSIONS: Allogeneic ASCs protected fat grafts at the early stage and improved long-term volume retention in the fat graft model of immunocompetent rats with no or little obvious immune rejection.
BACKGROUND: Syngeneic adipose-derived stem cells (ASCs) promote the survival of fat grafts. But it is unclear whether allogeneic ASCs have a similar protective effect. In this study, we investigated the protective effect of allogeneic ASCs in a fat graft model of immunocompetent rats. METHODS: Syngeneic and allogeneic ASCs were derived from Lewis (LEW) and Norway-Brown rats, respectively. Fifty-four LEW rats were divided into three groups. Each LEW rat was injected subcutaneously at two paravertebral spots with adipose granules premixed with DMEM (AFT group), syngeneic ASCs (SYNG group), or allogeneic ASCs (ALLG group). Fat grafts were harvested at 7 and 14 days to examine apoptosis rates and immunochemistry staining was performed for Perilipin A and CD34. At 3 months, fat graft volume retentions were measured. The proportion of regulatory T (Treg) cells and the ratio of CD4/CD8 cells in blood were analyzed at 7 days. RESULTS: Expression of Perilipin A and CD34 was higher in the ALLG group than the AFT group at 14 days (P < 0.05). The apoptosis rate in the ALLG group decreased in comparison with the AFT group at 7 and 14 days (P < 0.05). At 3 months, allogeneic ASCs increased fat graft volume retentions (P < 0.05). No difference was found in the proportion of Treg cells and CD4/CD8 cells ratio between groups. There were no statistically significant difference between ALLG and SYNG groups at all time points (P > 0.05). CONCLUSIONS: Allogeneic ASCs protected fat grafts at the early stage and improved long-term volume retention in the fat graft model of immunocompetent rats with no or little obvious immune rejection.