Hypoxic pretreatment of human umbilical cord mesenchymal stem cells regulating macrophage polarization

Objective 　To investigate the effect of human umbilical cord mesenchymal stem cells (hUC-MSCs) on macrophage polarization under hypoxia. Methods 　hUC-MSCs were obtained by explants adherent culture and cultured under normoxia (21% O2) and hypoxia (5% O2). The multi-directional differentiation of hUC-MSCs was observed by osteogenic and adipogenic differentiation induction. Live/death staining was performed to detect the cell viability, and ELISA was executed to detect the protein content in supernatant of hUC-MSCs. Transwell chamber was employed to co-culture the hUC-MSCs cultured under normoxia and hypoxia and macrophage (THP-1) stimulated by lipopolysaccharide (IPS), then the polarization of THP-1 was detected by immunofluorescence, and the secretions of inflammatory factor and anti-inflammatory factor of THP-1 were detected by ELISA. Results 　hUC-MSCs cultured under hypoxia showed the ability of osteogenic and adipogenic multi-directional differentiation. Live/death staining showed the high cell viability of hUC-MSCs cultured under normoxia and hypoxia. The expression levels of prostaglandin E2 (PGE2) and indoleamine 2,3-dioxygenase (IDO) were significantly higher in the hUC-MSCs cultured under hypoxia than in those cultured under normoxia. hUCMSCs cultured under hypoxia promoted the polarization of THP-1 to M2, obviously reduced the expression of TNF-α and IL-1β, and increased the expression of IL-10 significantly. Conclusion　hUC-MSCs cultured under hypoxia may promote the polarization of THP-1 to M2 and improve the viability of anti-inflammatory. DOI: 10.11855/j.issn.0577-7402.2016.07.01