Basic fibroblast growth factor and epidermal growth factor affecting the outgrowth and differentiation of embryonic neural stem cells

Objective:To study the effect of bFGF, EGF and the combination of the two on the differentiation of embryonic stem cells in culture. Methods; Embryonic E12 rats were obtained from anesthetized timed pregnant Sprague-Dawley rats. Neural stem cells were dissociated from embryonic neural tube. The expression of nestin was examineed at 2 h in culture. Following 5 d in culture, the immunocytochemical analysis was used to identify the expression of neuro-specific eno-lase (NSE) and glial fibrillary acidic protein (GFAP) in cultured cells. The immunostaining positive cells were counted at high fields in different groups. Results; Most of culture cells were nestin-positive. Four groups all promoted stem cells to grow and differentiate,EGF mainly affected the proliferation of neural stem cells and induced more cells differentiate into GFAP-positive cells (F0.01 vs control). bFGF not only affected the outgrowth of stem cells,but also promoted them to differentiation into NSE-positive cells. In bFGF + EGF group, more neurons and astrocytes could be seen in the immunostaining than control group (P0. 01). Conclusion .-Both bFGF and EGF can promote the outgrowth of embryonic stem cells,bFGF exerts a preferential effect on neuronal development and to a lesser extent,glial development,EGF may function as a stem cell survival factor,and induce stem cell to differentiate into astrocytes.