Dual Effects of Hypoxia on Proliferation and Osteogenic Differentiation
of Mouse Clonal Mesenchymal Stem cells
Abstract
Hypoxia is considered an important factor in the proliferation and
stemness of mesenchymal stem cells (MSCs). This study aimed to obtain
large numbers of mouse clonal MSCs (mc-MSCs) and evaluate the effect of
hypoxia on the proliferation and differentiation of mc-MSCs. mc-MSCs
were cultured on a Cytodex 3 microcarrier in a spinner flask for a
suspension culture to increase mass productivity. To produce the hypoxic
conditions, CoCl2 and Na2SO3 were used in a low glucose DMEM medium. The
hypoxia environment was established using 0.5g/L Na2SO3 with 10μM or 100
µM CoCl2 for 24 hours. As a result, the proliferation of mc-MSCs under
hypoxic conditions was 1.56 times faster than the control group over
seven days. 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.