Figure 4

Culture in hypoxia enhanced the potential of MSC to differentiate in adipocytes (A) and osteocytes (O). MSC were cultured in hypoxia or normoxia until P2, and shifted to adipocyte- or osteocyte-specific differentiation conditions respectively for 2-4 more weeks. The aspect of differentiated colonies under hypoxia is shown (A). In 2 independent experiments (B), MSC were harvested at P2, RNA from normoxic (N) or hypoxic (H) cells was extracted, reverse-transcribed and amplified by PCR with primers specific for control GAPDH and the indicated genes, representative of adipocytic (LPL, PPARγ) and osteocytic (ALPL, Runx2) lineages. The same cells were grown in osteocytic and adipocytic-specific medias and colonies were counted and compared to the numbers of CFU-F generated in MSC-specific medium (C).