Study On Directed Differentiation Of Human Umbilical Cord Blood Stem Cells Into Hepatocyte-Like Cells In Vitro

OBJECTIVE: To explore the possibility of differentiation of human umbilical cord blood stem cells into hepatocyte-like cell in vitro.METHODS: normal parturients' cord blood were collected . Mscs from human umbilical cord blood were isolated by density gradient centrifugation and adherence methods. Mscs were induced by HGF after purification and cultivation. The morphologic characteristics of the induced cells were observed. The markers of hepatic linear cells were examined before induction , and 0 , 7, 15 and 30 day after induction by RT-PCR ,immunocytochemistry and periodic acid-schiff (PAS). After that ,using transmission electron microscope to observe the ultrastructure of cells with HGF induction. Expression of MSCS' surface antigen CD34 and CD44 were detected by flow cytometry.RESULTS: 1.the density gradient centrifugation and adherence methods are fit for the separation and growth of umbilical cord blood stem cells . 2.the induced cells after purificating and going down to the third generation shows ultrastructure of hepatocyte-like cells. 3. Whereas in the groups without HGF induction, the cells did not express hepatocellular markers: ALB,amylon but AFP in 0 day . Whereas in the groups with HGF induction, the cells express hepatocellular markers: ALB,amylon and AFP. The third generation cells express surface antigen CD44 but not CD34. CONCLUSION: 1. human umbilical cord blood stem cells can be isolated successfully with density gradient centrifugation and can be cultured successfully with adherence methods. 2. human umbilical cord blood stem cells could be induced into the hepatocyte-like cells by HGF in vitro.The expression of the markers of hepatocyte coincided with the development of liver cell. The morphology features of hepatocyte-like cells induced from umbilical cord blood stem cells are similar to hepatocyte.