Hypoxia induces the migration of endothelial progenitor cells

Zhao Hui; Gao Yu-zhong

doi:10.3969/j.issn.2095-4344.0810

Abstract：BACKGROUND: Local endothelial progenitor cells (EPCs) have been reported to promote migration and homing of EPCs by releasing stromal cell-derived factor-1 (SDF-1) under hypoxia environment. OBJECTIVE: To investigate the effect of different hypoxia periods on the expression of SDF-1 protein in EPCs and the migration of EPCs, thus providing new ideas for the treatment of ischemic diseases. METHODS: The bone marrow of the long bone was removed from Sprague-Dawley rats used for isolate EPCs. After culture and identification, EPCs were divided into four groups: control (normoxia), 6-, 12- and 24-hour hypoxia groups. The expression level of SDF-1 in the supernatant of EPCs in each group was detected by ELISA and immunofluorescence. The mRNA and protein levels of SDF-1 were detected by RT-PCR and western blot assay. The effect of hypoxia on the migration of EPCs was tested by Transwell assay. RESULTS AND CONCLUSION: The obtained cells were identified as EPCs. ELISA and immunofluorescence results showed that compared with the control group, the expression level of SDF-1 began to increase at 6 hours of hypoxia, peaked at 12 hours of hypoxia, and then decreased at 24 hours of hypoxia. RT-PCR and western blot assay results found that the mRNA and protein expression levels of SDF-1 were the highest in the 12-hour hypoxia group, followed by 6- and 24-hour hypoxia groups, and the lowest in the control group (P < 0.01). The number of EPCs penetrating the membrane in the 12-hour hypoxia group was significantly more than that in the 6- and 24-hour hypoxia groups, and the number in the 24-hour hypoxia group was significantly more than that in the control group (P < 0.05). In summary, hypoxia can promote the secretion of SDF-1 and induce the migration of EPCs.