ABSTRACT
Human placental decidua basalis-mesenchymal stem cells (PDB-MSCs) are multipotent cells from the human term placenta, which are ethically conducive, easily accessible and high-yielding source. PDB-MSCs can differentiate into adipogenic, osteogenic and neurogenic cells under appropriate conditions, which may be an attractive and alternative source of seed cells for tissue engineering. To investigate the effect of hypoxia (1% O2) on human PDB-MSCs and the expression of cytokine, PDB-MSCs were isolated from human placenta by density gradient centrifugation and cultured in the Dulbecco's modified Eagle's medium-high glucose (DMEM-HG) containing 10% fetal bovine serum (FBS), and the fifth passage of PDB-MSCs were taken. PDB-MSCs were divided into 4 groups according to the concentrations of O2 and FBS: 20% O2, 10% FBS; 20% O2, 0% FBS; 1% O2, 10% FBS; 1% O2, 0% FBS. The proliferation and apoptosis of PDB-MSCs were detected by MTT and flow cytometric analysis at the time points of 6 h, 12 h, 24 h, 48 h, 72 h, and 96 h, respectively. Vascular endothelial growth factor (VEGF) released from PDB-MSCs was detected by enzyme-linked immunosorbent assay (ELISA) at the same time points. The results showed that hypoxia enhanced the proliferation of PDB-MSCs at 12 h under the condition of 10% FBS, while at 24 h under the condition of 0% FBS (P<0.01, n=3). In normoxia, the cells cultured in 10% FBS displayed a significant proliferation compared to those cultured in 0% FBS. However, in hypoxia, the number of cells cultured in 0% FBS (serum deprivation) increased significantly compared to that cultured in 10% FBS at 24 h and 96 h respectively (P<0.05, P<0.01, n=3). With the flow cytometric analysis of cell apoptosis under the condition of hypoxia and serum deprivation, we found that hypoxia and serum deprivation did not induce PDB-MSCs apoptosis (P>0.05, n=3). This conclusion may relate to the expression of VEGF which needs further research. In conclusion, the results obtained indicate that PDB-MSCs are able to bear hypoxia and serum deprivation, suggesting that PDB-MSCs can be used as seed cells for ischemia related tissue engineering.