Immunosuppressive effects of mesenchymal stem cell transplantation in rat burn models.

OBJECTIVE: This study is to investigate the effects of mesenchymal stem cell (MSC) transplantation in burn treatment.

METHODS: Wharton's Jelly was stripped from neonatal umbilical cord, and human umbilical cord MSCs were then cultured. Burn models were constructed in male SD rats weighted at 200±5 g, and the rats were randomly divided into control and MSCs transplantation groups. The rats in transplantation group were injected subcutaneously with MSCs (2×10(6)) at 24 h after burning. Blood samples were collected at 0 d, 1 d, 2 d, 3 d, 5 d and 7 d after burning and the contents of white blood cells (WBC), C-reactive protein (CRP), interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10 ) were detected. The wound healing rate at 7 d, 14 d, 21 d and 28 d together with the wound healing time were compared and analyzed statistically by analysis of variance (ANOVA).

RESULTS: WBC and CRP in control group increased significantly at 1 d and 2 d, 2 d and 3 d, respectively. IFN-γ, IL-6 and IL-10 levels in serum showed increasing till 5th day and TNF-α arrived its peak value at 7th day. By contrast, WBC, CRP, TNF-α, IL-6 and IL-10 in the MSCs transplantation group showed slight increase after burning and the differences were verified by statistically analysis. IFN-γ showed no significant difference between the two groups. MSCs transplantation group showed significantly higher wound healing rate at 14 d, 21 d, 28 d and showed shorter wound healing time than control.

CONCLUSIONS: MSCs transplantation could suppress secondary inflammatory reaction by lowering inflammatory cytokines after burning, thus promoting wound healing and scald repair in burn animal model.