RÉSUMÉ
Objective It has traditionally been difficult to isolate and culture mouse bone marrow mesenchymal stem cells (BMSC),which has low success rate.And thus restricts the development of related research to some extent.We aimed to optimize the whole bone marrow adherent method for isolation and culture of mouse bone marrow mesenchymal stem cells and search for an effective method of inducing BMSCs to differentiate into alveolar epithelial cells.Methods Bone marrow contents harvested from the tibia and femur of C57BL/6 mice were cultured based on the whole bone marrow adherent method.The timing and split ratios of passage were determined according to the size and number of cell colonies.After 6 passages,cells were counted to detect cell proliferation ability,surface markers were examined by flow cytometry and Small Airway Epithelial Cell Medium (SAEpiCM) was used to induce the differentiation of BMSCs.Results With the increase of passages and the purity of BMSCs,the proliferation of cells at passages 6 tended to be stable.Flow cytometry showed that they were strongly positive for bone marrow mesenchymal stem cell surface markers CD29 and Sca-1 (99.1％,88.5％),but almost negative for the surface marker of hematopoietic stem cells CD117 (0.008 2％).BMSCs cultured in SA-EpiCM showed an epithelium-like morphological change and expressed surfactant associated protein C,a specific marker of alveolar epithelial cells.Conclusion It is effective to isolate and culture mouse bone marrow mesenchymal stem cells by adjusting the timing and split ratios of passage according to the size and number of the clonal cell colonies,which possessed the potential to differentiate into alveolar epithelial cells.