Abstract: Objective To study the potential of transplanted bone marrow-derived mesenchymal stem cells (MSCs) in treating and repairing the acute lung injury in animal models. Methods MSCs were isolated from mouse bone marrow of healthy donors,cultrued and amplified in vitro. The lipopolysaccharide (LPS) was inhaled along postnasal tract to produce acute lung injury in mice and the MSCs labeled by Brdu were administrated via vein into the mice. The migration and differention of the cells were identified by immunostaining and double immunostaining. The pathological changes, pulmonary edema index and the content of IL-1β in lung homogenate were used to accese the therapeutical effect of MSCs. Results The cultured MSCs dispalyed a positive CD44 and a negative CD34.The Brdu-labeled cells were detected in the lungs of the recipient 4 days after transplantation, indicating its origin of MSCs.Theses cells also exhibited characteristics of aveolar epithelials,expressing the cytokeratin-the marker of epithelium. Compared with the injuried ones, the mice under the therapy with MSCs showed a decreased pulmonary edema index and IL-1β content in the lung homogenate. Conclusion These data suggest a therapeutical effects of MSCs in treating and repairing the mouse acute lung injury.

Key words: bone marrow-derived mesenchymal stem cells, acute lung injury, lipopolysaccharide