Dual effects of hypoxia on proliferation and osteogenic differentiation of mouse clonal mesenchymal stem cells.

Abstract

Mouse clonal mesenchymal stem cells (mc-MSCs) were cultured on a Cytodex 3 microcarrier in a spinner flask for a suspension culture under hypoxia condition to increase mass productivity. The hypoxia environment was established using 4.0mM Na2SO3 with 10μM or 100µM CoCl2 for 24h in a low glucose DMEM medium. As a result, the proliferation of mc-MSCs under hypoxic conditions was 1.56 times faster than the control group over 7days. The gene expression of HIF-1a and VEGFA increased 4.62 fold and 2.07 fold, respectively. Furthermore, the gene expression of ALP, RUNX2, COL1A, and osteocalcin increased significantly by 9.55, 1.55, 2.29, and 2.53 times, respectively. In contrast, the expression of adipogenic differentiation markers, such as PPAR-γ and FABP4, decreased. These results show that the hypoxia environment produced by these chemicals in a suspension culture increases the proliferation of mc-MSCs and promotes the osteogenic differentiation of mc-MSCs.