Embryonic stem (ES) cells have been utilized as an excellent model for the study of neural development. However, the dynamic changes of ES cell-derived neural stem cells (ES-NSCs), under the effects of prolonged cell culture and hypoxic conditions, are still obscured. In the present study, using the combination of serum-free culture of embryoid body-like aggregates (SFEB) culture and cell sorting by Sox-1, the ES-NSCs were easily isolated and showed in vitro temporal neural specification, which resulted in distinct cell fates after neural differentiation. Early passaged ES-NSCs gave rise to neurons, whereas late-passaged ES-NSCs gave rise to glial cells, similar to the in vivo dynamic changes during the neural development. Remarkably, hypoxia treatment induced the neural differentiation of ES-NSCs but did not affect the cell fate. Under hypoxic conditions, early passaged ES-NSCs showed the upregulation of neuronal markers, whereas late-passaged ES-NSCs showed the upregulation of a glial marker. In addition, the knockdown of the hypoxia-inducible factor 1α expression impaired the neuronal differentiation of early passaged ES-NSCs under hypoxic conditions. These data demonstrated the distinct effects of prolonged culture and hypoxic stimuli on the neural differentiation of ES-NSCs; prolonged culture was involved in the cell fate after neural differentiation, while hypoxia treatment efficiently promoted neural differentiation.
Keywords: ES cell-derived neural stem cells; cell fate; hypoxia; neural differentiation; prolonged cell culture.