hMSC osteogenesis is inhibited by RA and enhanced by EGF+bFGF.

<p>hMSC were cultured for 21 days in osteoblasts differentiation medium without serum supplemented with 10% FBS (A), 10% FBS +0.5 µM RA (C), nothing (D), 0.5 µM RA (E), 20 ng/ml EGF +5 ng/ml bFGF (F), 20 ng/ml EGF +5 ng/ml bFGF +0.5 µM RA (G), or were cultured in DMEM supplemented with 10% FBS (B) or with 20 ng/ml EGF +5 ng/ml bFGF (H) (negative controls). To visualize differentiation osteoblasts were stained with alizarin red after fixation in 70% ethanol. Size bars = 100 µm.