Résumé
Objective To induce and identify the differentiation of rat bone marrow mesenchymal stem cells(MSCs)into cardiomyocytes in vitro,and observe the expression of Nesprin protein during the differentiation. Methods Rat MSCs were isolated and purified by Ficoll density gradient centrifugation,and adhered for serial subcultivation.Surface-associated antigens of MSCs of the second passage were dedected by flow cytometry.MSCs of the second passage were induced by 10μmol/L 5-azacytidine(5-Aza)to differentiate into cardiomyocytes,and the morphological changes were observed.The expression of Desmin,α-sarcomeric actin and cardiac Troponin I(cTnI) mRNA and protein was detected by RT-PCR,immunocytochemistIv and immunofluorescence staining, and the expression of Nesprin protein was detected by Western blotting. Results The morphology of MSCs induced by 5-Aza was bigger and longer,and the nuclei became bigger,exhibiting more consistent patterns.The expression of Desmin,α-sarcomeric actin and cTnI mRNA and protein of MSCs was positive.Immunofluorescence staining revealed that Nesprin protein positioned in the nuclear membrane,and Western blotting detection demonstrated that the expression of Nesprin protein significantly increased after differentiation(P<0.05).Conclusion MSCs may be successfully induced to differentiate into cardiomyocytes.The expression of Nesprin protein in the differentiated MSCs may significantly increase,indicating Nesprin may play a role in the differentiation from MSCs to cardiomyocytes.