[Microenvironment for the hematopoietic differentiation of human embryonic stem cells]

To investigate the roles of human fetal liver stromal cells (hFLSCs) and human fetal bone marrow stromal cells (hFBMSCs) in the hematopoietic differentiation of human embryonic stem cells and analyze their gene expression profile changes.

The embryonic bodies on day 4 were cocultured with hFLSCs or hFBMSC in the presence of cytokines. Flow cytometry was performed after 8 days of induction to detect the expressions of the hemangioblast markers KDR and CD34, and the differential gene expression profiles between hFBMSC and hFLSCs were examined by cDNA microarray analysis.

Eight days after the induction, (1.06-/+0.20)% of the hFLSCs and (8.8-/+1.49)% of the hFBMSCs were positive for KDR, with the positivity rates for CD34 of (1.25-/+0.16)% and (9.17-/+2.10)%, respectively. In hFLSCs and hFBMSCs cultures, 0.9-/+0.36 and 10.6-/+0.63 hemagioblast-like cell colonies were found, respectively. cDNA microarray analysis showed that 240 genes were highly expressed in hFBMSCs, and 21 genes related to secreted cytokines, cell adhesion molecules and extracellular matrix proteins were highly expressed.

The microenvironment including the cell matrix protein and cytokines secreted by the hFBMSCs might play an important role in hemangioblastic differentiation of human bone marrow stromal cells in vitro.