Fig. 4

Hypoxia enriches for neural progenitors in human BMSCs. Representative images of human BMSC-derived neurosphere formation following normoxia (a, c) and hypoxic preconditioning (b, d). Numbers of neurospheres significantly increased in response to hypoxia (e). A reduction in sphere numbers was observed in both groups with the addition of erlotinib. However, hypoxia-treated human BMSCs yielded significantly more spheres in the presence of the EGFR inhibitor. Diameter of spheres remained similar irrespective of normoxia/hypoxia preconditioning or test/control treatment with Erlotinib (f). Numbers of nestin-positive cells within neurospheres were similar amongst both treatment groups (g). Mean ± SD, n = 8 for sphere counting, n = 4 for quantification of nestin-positive cells; *p < 0.05, **p < 0.01