ABSTRACT
Objective:To investigate the induction of tanshinoneⅡA (TanⅡA) on the differentiation of human placenta-derived mesenchymal stem cells (hPDMSCs) into cardiomyocytes, and to provide an experimental basis for TanⅡA as a cardiomyocyte differentiation inducer.Methods:The hPDMSCs were treated with different concentrations of TanⅡA (0.1, 0.2, 0.4, 0.6, 0.8, 1.0, 2.0, 4.0, 6.0, 8.0, and 10.0mg·L-1) , and the nontoxic dose of TanⅡA (0.1mg·L-1) was screened by MTT assay for experiment.The hPDMSCs were divided into control group, 5-aza induction (10μmol·L-1) group, and TanⅡA induction (0.1mg·L-1) group.After culture for 20d, the expressions ofα-sarcomeric actin (α-SCA) in the cells in various groups were detected with immunohistochemistry;the positive expression rates of cardiac troponin I (cTnI) in the cells in various groups were detected with immunofluorescence, and the differentation rates of cardiomyocytes were calculated.The expression levels of GATA-binding protein 4 (GATA4) , atrial natriuretic factor (ANF) , cTnI, glycogen synthase kinase-3β (GSK-3β) andβ-catenin in the cells were detected with Western blotting method.Results:The biological characteristics of hPDMSCs accorded with the mesenchymal stem cells.The MTT results showed that when the concentration of TanⅡA was more than 0.1mg·L-1, the cell survival rates were decreased with the increase of concentration;the cells in control group showed a rapid growth trend before 12d, and the proliferation activities of the cells began to decrease on the 12th day.Compared with control group, the cell activities in 5-aza induction group and TanⅡA induction group were significantly decreased (P＜0.05) .The immunohistochemistry staining results showed that the cells in control group didn't expressα-SCA, and the cells in 5-aza induction group and TanⅡA induction group expressedα-SCA, especially in TanⅡA induction group.Compared with control group, the expression levels of GATA4 (t5-aza=2.937, P5-aza＜0.05;tTanⅡA=4.769, PTanⅡA＜0.05) , ANF (t5-aza=3.728, P5-aza＜0.05;tTanⅡA=5.912, PTanⅡA＜0.05) , cTnI (t5-aza=3.623, P5-aza＜0.05;tTanⅡA=7.153, PTanⅡA＜0.05) and GSK-3β (t5-aza=2.995, P5-aza＜0.05;tTanⅡA=5.420, PTanⅡA＜0.05) proteins in the cells in 5-aza induction group and TanⅡA induction group were significantly increased, and the expression levels ofβ-catenin (t5-aza=2.985, P5-aza＜0.05;tTanⅡA=6.951, PTanⅡA＜0.05) protein were significantly decreased;compared with 5-aza induction group, the expression levels of GATA4, ANF, and GSK-3βproteins in TanⅡA induction group were increased (P＜0.05) .Conclusion:TanⅡA can induce the differentiation of hPDMSCs into cardiomyocytes, which has better effect than 5-aza, and its mechanism may be related to inhibiting the Wnt/β-catenin signaling pathway.