不同造血微环境对诱导人胚胎干细胞向造血干细胞分化的影响

Object: We observed the inductive efficiency of deriving hematopoietic stem cells from human embryonic stem (hES) cells co-cultured with human yolk sac stromal cells、fetal liver stromal cells or fetal bone marrow stromal cells，in order to discuss the effect of the different hemopoietic microenvironment on hemopoietic cytogenesis. Methods: We used two-step method inducing the hES cells into hematopoietic stem cells. In the first step the hES cells were co-cultured with cytokines by formation of the day-5 embryoid bodies (5dEBs). In the second step the 5dEB cells were induced into hematopoietic stem cells by co-culture with human yolk sac stromal cells、fetal liver stromal cells or fetal bone marrow stromal cells for ten days. The inductive efficiency of deriving hematopoietic stem cells from hES cells co-cultured with the different hemopoietic microenvironment was reflected by the expressive levers of flk、CD31 and CD34 antigen. Results: The results of flow cytometry analysis demonstrated that the population of the cells co-cultured with human yolk sac stromal cells contained flk 2.0 %、CD34 0% or CD31 2.0% positive cells; the population of the cells co-cultured with human fetal liver stromal cells contained flk 0%、CD31 0.7% and CD34 1.4% positive cells; the population of the cells co-cultured with human fetal bone marrow stromal cells contained flk 1.5%、CD31 5.6% and CD34 0.7% positive cells. Conclusion: The human yolk sac stromal cells can promote the hES cells differentiation into hemangioblast. The human fetal liver stromal cells can promote the hES cells differentiation into hematopoietic stem cells. The human fetal bone marrow stromal cells can promote the hES cells differentiation into both hemangioblast and hematopoietic stem cells.