The Research Of Directional Differentiation Of Bone Marrow-Derived Mesenchymal Stem Cells By Direct Cell-to-Cell Contact With Cardiomyocytes

Objecfive:To study transdifferentiation of bone marrow-derived mesenchymal stem cells into cardiomyocytes and the expression of cardiomyocyte specific markers by SD in rat bone marrow-derived mesenchymal stem cells (BM-MSC) and the myocardial cells of neonatal rats (CMs) in direct contact co culture method in vitro.Methods:Take four weeks old SD rats, separate and cultivate ectomesenchymal stem cells, bone marrow cells were observed under inverted phase contrast microscope. The identification of surface antigen CD29,45,CD44,CD90, CD11b of BM-MSC by flow cytometry. The BM-MSC were induced to differentiate along the osteogenic, chondrogenic and adipogenic lineages.Take 1 to 2 days rats, separate and cultivate myocardial cell. To detect expression of Cardiac-specific troponin T(cTnT)?troponin I(cTnI)and ?-actin in the postive cells by Immunohistochemistry. With DAPI tag BM- MSC, direct contact with rats myocardial cell co-culture differentiate into myocardial cells, the detection of cardiac muscle specific protein expression.Results:The morphological characteristics of SD in rat BMMSCs in vitro primary culture:the primary BM-MSC forms, with fusiform, round, spindle shaped and polygonal cells are most common, aggregate growth trend, a plurality of cells to form a colony. Increasing, the size of cells after the wedding form is relatively uniform, sample to fibroblasts, long spindle, cells were once high, debris or mixed cell number is also reduced. Cell cycle analysis showed that BM-MSC is about 15% in the period of active replication, the vast majority of the remaining cells arrest in G0/G1 (84.9%), indicating that most of the cells with a high degree of differentiation. Using flow cytometry instrument detection BM-MSC surface specific antigen CD44, CD29,CD90 express positive, surface antigen expression of CD44 and CD11b negative. Direct contact with the culture of BM-MSC express myocardial specificity of troponin T-. specific troponin I and a-actin, the positive expression of -actin was the highest, followed by CTnT, the positive expression rate of CTn1 was the lowest.Conclusion:Between bone marrow mesenchymal stem cells in direct contact with myocardial cell culture conditions, sample BM-MSC can differentiate into myocardial cells, and can express myocardial specificity of troponin T? specific troponin I and a-actin.