Human Umbilical Cord-Derived Mesenchymal Stem Cells Alleviate Acute Lung Injury Caused by Severe Burn via Secreting TSG-6 and Inhibiting Inflammatory Response

Abstract Objectives To investigate whether hUC-MSCs attenuated severe burn-induced ALI and the effects were based on TSG-6 secreted from hUC-MSCs. Method Rat model was established and evaluated as follows：cytokine expression was measured by ELISA assay, and both inflammatory cell infiltration and lung injury were assessed by immunohistochemistry assay. Results In vitro, TSG-6 levels in serum from the burn group were significantly increased than that of the sham group. In vivo, TSG-6 levels of lung tissues and serum in the burn+ hUC-MSCs group were significantly increased than those of that in the burn group. Both in lung tissues and serum, increased levels of proinflammatory cytokines（TNF-α, IL-1β, IL-6）were remarkably decreased, but anti-inflammatory cytokine IL-10 increased after hUC-MSCs administration (p<0.05). These significant positive effects after hUC-MSCs transplantation did not occur in the Burn+siTSG-6 group. Conclusion Intra-tracheal implantation of hUC-MSCs has been an effective treatment for severe burn-induced ALI via promoting TSG-6 secretion and inhibiting inflammatory reaction in lung tissue.