Abstract:

BACKGROUND: It is theoretical and clinical significance of studying the condition and technique of the differentiation of embryonic stem cells embryonic stem cell (ESC) into cardiomyocytes and to further elevate rate of differentiation and cell purity.
OBJECTIVE: To set up a model of inducing ESC into cardiomyocytes and to provide a suitable method to study development of cadiomyocytes in vitro. 
METHODS: Undifferentiated ESC were incubated in vitro by hanging drop-suspension-adherence method (hanging drop culture), then divided into six groups according to different inducers added in the culture system: group Ⅰ (salvia miltorrhiza linked with 5-azacytidine as inducer), group Ⅱ (salvia miltorrhiza and retinoic acid as inducer), group Ⅲ (5-azacytidine as inducer), group Ⅳ (salvia miltorrhiza as inducer), group Ⅴ (retinoic acid as inducer), and group Ⅵ (no inducer). After inducer addition, Cardiomyocyte marker proteins expression of α-actinin, myosin, and α-actin were detected by immunocytochemistry in the ninth day. RESULTS AND CONCLUSION: Spontaneously contracting cells appeared in thesecond day following inducer addition under inverted microscope and one embryoid body had one or more contraction foci. The immunocytochemistry showed the cardiomyocyte marker proteins expression of α-actinin, myosin, α-actin were positive. The rate of differentiation of group Ⅰ was highest, which showed significant difference compared with groups Ⅱ and Ⅵ (P  < 0.01), and exhibited significant difference compared with groups Ⅲ, Ⅳ and Ⅴ (P < 0.05). it suggested that traditional Chinese drug salvia miltorrhiza linked with 5-azacytidine as inducers in culture system of hanging drop cultures can improve rates of ESC into cardiomyocytes differentiation in vitro.