Experimental Study On The Differentiation Of Mesenchymal Stem Cells Induced By 5-azacytidine To Cardiomyocytes

Mesenchymal stem cells(MSCs) from rat bone marrow are the stem cells which have the abilities to differentiate in various directions. In some conditions, the MSCs can be induced to differentiate to be osteoblasts, chondrocytes, fat cells, myocytes, cardiac myocytes. The MSCs can be obtained easily and can be autotransplantated. The MSCs provide the good cell sources for reparation and reconstruction of the bone, cartilage and heart. The objects of this study is to investigate the myogetic differentiation of the MSCs induced by 5-azacytidine in vitro and in vivo in rabbits and provide the new clue to cell transplantation of injured cardiac tissues. The study includes the following:1. The convenient, efficient and practical method for the MSCs from rabbits isolation and culture in vitro was established after the repeated practices. The MSCs were gotten by gradient centrifugation and the expressions of surface antigens were monitored by flow cytometer. The results showed good cell uniform, negative expression of CD34 and positive expression of CD44. So the purity of the MSCS ishigh.2. Experiments in vitro: The MSCs were induced by 5-azacytidine as the seed cells.Then the cells cultured for 7, 14, 21, 28 days were immunohitochemistrical stained for determining the myosin heavy chain. The results showed that the cells cultured for 21, 28 days were positively stained in the experimental group and the cells cultured for 7. 14 days in the experimental group and the cells cultured for all kinds of periods in the control group were negatively stained. So the probability of myogetic differentiation of the MSCs was approved. At the meantime, we found that the best inducing period of 5-azacytidine was 72 hours and the best inducing concentration was 10umol/L.3. Experiments in vivo: The MSCs induced by 5-azacytidine as seed cells were autotransplanted to myocardial infarction field for further improving the study of myogetic differentiation of the MSCs. The results showed that the MSCs continued their myogetic differentiation in vivo and fused with the host cardiac cells to repair the injured cardiac muscle. At the same time, the MSCs also accelerated the angiogenesis aroud them.The above-metioned study showed: The isolated and cultured MSCs from rat bone marrow have the ability of myogetic differentiation induced by 5-azacytidine. A new kind of seed cell was found for tissue engineering reparation. The MSCs as seed cells induced in vitro were used to treat the ischemic heart disease with the micro injection tecknique. So the study of myogetic differentiation of the MSCs was further improved. The new method for treating the heart failure was found and the experimental basis was given for the clinic practise.