A STUDY OF INCUBATION AND INITIAL IDENTIFICATION OF MURINE YOLK SAC MESENCHYMAL STEM CELLS / 解剖学报

ABSTRACT

Objective To investigate the isolation,incubation and identification of murine yolk sac mesenchymal stem cells(YS-MSCs). Methods Murine yolk sacs were harvested on the 10th day of postcoitus microisolation.Yolk sac cells were obtained after the yolk sacs were digested by type Ⅰ collagenase of 0.1% for 1 hour.Adherent cells were cultured in DMEM containing 10% FBS and 1% SP,and passaged when they became subconfluent.The ultrastructure of YS-MSCs was observed under transmission electron microscope;the surface markers of YS-MSCs were detected by flow cytometry;the alkaline phosphatase(AKP) expression of YS-MSCs was tested;and cytochemical changes of YS-MSCs were observed with cytochemical detection.Adipogenic differentiation of YS-MSCs was induced by 1?mol/L dexamethasone and 10mg/L insulin,and oil red O was used for fat staining. Results YS-MSCs were obtained in vitro,and most of them were of spindle shape;under transmission electron microscope,there were microvilli on the surface of YS-MSCs,there were abundant mitochondria,rough endoplasmic reticulum and golgi complex in the endochylema.The cell nuclei of YS-MSCs were big and the shape of cell nucleus was irregular;the analysis of flow cytometry suggested that the primary and first generation of YS-MSCs were positive for CD44,CD105,and the expression of CD34 was small;Cytochemistry showed that YS-MSCs were positive for glycogen,and negative for SB and AKP;Adipogenic differentiation of YS-MSCs was induced by 1?mol/L dexamethasone and 10mg/L insulin;accumulation of lipidrich vacuoles appeared in the cells,positive for oil red O staining.Conclusion The biological characteristics of murine yolk sac mesenchymal stem cells are similar to,and more primitive than,those of adult mesenchymal stem cells.It suggests that YS-MSCs may be used as an ideal resource of seed cells of tissue engineer.