Abstract:

BACKGROUND: The cytokines secreted by bone marrow mesenchymal stem cells (BMSCs) can be affected by hypoxia. Its mechanism may exert effects via hypoxia inducible factor-1 α (HIF-1 α).
OBJECTIVE: To observe HIF-1 α, stromal derived factor 1 α (SDF-1 α) and vascular endothelial growth factor (VEGF) gene expression affected by HIF-1 α small interfering RNA (siRNA) in BMSCs.
METHODS: BMSCs were cultured by adherence method. The third to fifth passages of BMSCs were selected for experiments. Inverted microscope was used to observed morphology. Flow cytometry was used to detect the expression of surface markers CD34, CD44 and CD90. BMSCs were divided into four groups, normal control group (without any treatment), hypoxia group (hypoxia for 24 hours), liposome control group (BMSCs transfected with liposome then hypoxia for 24 hours), RNA interference (BMSCs transfected with RNA interference sequences then hypoxia for 24 hours). Reverse transcription-polymerase chain reaction was utilized to determine HIF-1 α, SDF-1 α and VEGF mRNA expression in BMSCs. Enzyme linked immunosorbent assay was employed to detect HIF-1 α, SDF-1 α and VEGF protein expression in BMSCs.
RESULTS AND CONCLUSION: Compared with the normal control group, HIF-1 α, SDF-1 α and VEGF mRNA and protein expression increased in the hypoxia group (P < 0.05). Compared with the lipsome control group, HIF-1 α, SDF-1 α and VEGF mRNA and protein expression decreased in the RNA interference group (P < 0.05). These verified that hypoxia increased SDF-1 and VEGF gene expression. Inhibition of HIF-1 α expression decreased SDF-1 α and VEGF expression. HIF-1 α may be a regulatory factor for cytokine secretion following stem cell transplantation.