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Objective To investigate the in vitro rat bone marrow mesenchymal stem cells (marrow mesenchyma stem cells, MSCs) and cardiac muscle cells (cardiomyocytes, CM) separation, culture and 5 - azacytidine (5-Aza) and co-culture of two methods of MSCs induced differentiate into the role of CM; different ways to induce MSCs to differentiate MSCs differentiation in different time periods for the CM's ability and expression of a specific marker of myocardial cells connexin 43 (Cx43), troponin T (cTnT) difference for MSCs transplantation in the treatment of acute myocardial infarction (acute myocardial infarction, AMI) provides a theoretical basis. Isolated under sterile conditions Wistar rat femur bone marrow using density gradient centrifugation and adherent culture combined MSCs cultured, purified and amplified in parallel transmission electron microscopy identification. With neonatal rat heart, isolated under sterile conditions using the the differential adherence Law CM culture, purified in parallel of Cx43 detection of cTnT immunocytochemistry. Select stable cell lines grew well in the third generation of MSCs with 4 ', 6 - diamidino-2 - phenylindole (DAPI) mark, divided into three groups: ① normal control group: DAPI-MSCs in grown in normal medium; ② 5-Aza-induced group: DAPI-MSCs added 5-Aza-induced, with different concentrations of 5-Aza role is not the same length, parallel immunohistochemical identification of cTnT in order to observe the optimal concentration and duration of action of Cx43; (3) co-culture group: co-cultured with the CM cultured for 3 days. After incubation, 1w, 2w, 3w, 4w observed under an inverted phase contrast microscope structural changes of cell morphology and immunocytochemical staining identification of cTnT, Cx43, and calculate its induced positive rate. Wistar rat MSCs separation adherent purified in vitro proliferation and maintain the undifferentiated potential. With neonatal rat CM separation, one day after the adherent that can beat spontaneously in culture 2-3d can grow into a single layer and the formation of cell clusters, and clusters of cells synchronized pulsatile. 10μmol / L 5-Aza continued for 15 days of MSCs, 4w showing typical changes of myocardial cells, some cells appear spontaneously and a frequency of 15 to 20 beats / min. MSCs 3rd passage labeled with DAPI labeling efficiency of 100%, DAPI-MSCs in normal medium, no cell contraction, cTnT, Cx43 expression was negative; induction group and co-culture group, cell culture to 4w arranged in the direction of (?) caused, arranged into a muscle, some cells showed pulsatile induced 1w The cTnT content in serum, Cx43 negative expression induced 2w cTnT positive rate (9.98 ± 1.67)% of Cx43 positive rate (13.38 ± 2.15)% cultivate to higher positive rate when 4w, 3w, 2w compared (P lt; 0.01); the coculture group first five days cTnT, Cx43 expression started with the incubation time, the positive ratio increased 4w The cTnT content in serum the Cx43 positive rate, respectively (88.3 ± 1.33)%, (90.38 ± 1.87)%, and 3w, 2w, 1w compared (P lt; 0.01); comparison within the same number of weeks, co-culture group were significantly higher than the induced group (P lt; 0.01). Conclusion MSCs in vitro proliferation and maintain their differentiation potential characteristics the CM by differential paste wall separation and purification, cell purity of 95% or more. MSCs induced by the appropriate concentration of 5-Aza and co-cultured with CM can be transformed into myocardial cells and express specific markers of myocardial cells of cTnT, Cx43, and co-cultured MSCs to differentiate into myocardial cells' ability to induce strongly than 5-Aza.
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