Effects of hypoxia on proliferation of human cord blood-derived mesenchymal stem cells

The purpose of our study was to examine the influence of hypoxia on proliferation of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs). The mononuclear cells were separated by density gradient centrifugation from human umbilical cord blood and then, respectively, cultured under hypoxia (5 % O-2) or normoxia (20 % O-2). Their cell morphology, cell surface markers, beta-galactosidase staining, cell growth curve, DNA cycle, and the expression of hypoxia-inducible factor-1 alpha (HIF-1 alpha) were evaluated. We found that hypoxia, in part via HIF-1 alpha, improved the proliferation efficiency, and prevented senescence of hUCB-MSCs without altering their morphology and surface markers. These results demonstrated that hypoxia provides a favorable culture condition to promote hUCB-MSCs proliferation in vitro, which is a better way to obtain sufficient numbers of hUCB-MSCs for research and certainly clinical application.