[Dynamic changes of gene expression profiles during cardiomyogenesis of human marrow mesenchymal stem cells].

OBJECTIVE: To analyze the changes of gene expression profiles during the process that human bone marrow mesenchymal stem cells (hBMSCs) are induced to differentiate into cardiomyogenic cells with 5-azacytidine (5-aza).

METHODS: hBMSCs were isolated from marrow of obsolete ribs and induced with 5-aza. Then immunocytochemical staining was used to detect the expressions of alpha-actin, cardiac troponin T (cTnT), and connexin 43, and the percentage of cTnT positive cells was tested with flow cytometry. In the process of differentiation, variation of gene expression was screened with Genechips Operating System of human gene expression profiles. And the differentially expressed genes were functionally analyzed and hierarchical clustered.

RESULTS: When BMSCs were induced in vitro with 5-aza, part of the cells turned into myogenic cells morphologically. Before induction, immunocytochemical staining for alpha-actin and cTnT showed slight positive and for connexin 43 showed negative. While after 3 weeks of induction, immunocytochemical staining for alpha-actin, cTnT, and connexin 43 showed all positive. With flow cytometry, the percentage of cTnT positive cells was 7.43% +/- 0.02% before induction, but it was 49.64% +/- 0.05% after induction. During differentiation, 1 814 differentially expressed genes were reported by gene chips. Of them, 647 genes were divided into 5 groups with hierarchical clustering. They had various biological functions, involving signal transduction, cell metabolism, proliferation, differentiation, development, and topogenesis.

CONCLUSION: hBMSCs can differentiate into cardiomyogenic cells with the induction of 5-aza in vitro. Multiple genes related with signal transduction, transcription, and growth factors are involved during this process.