Abstract:

Objective To investigate the role of vascular endothelial progenitor cells（EPCs）angiogenesis induced by SDF⁃1α/CXCR4 in neurological rehabilitation after stroke. Methods Flow cytometry and ELISA were used to analyze the effects of EPCs on oxygen⁃glucose deprivation（OGD）⁃induced apoptosis and SDF⁃1α levels in human brain microvascular endothelial cells（HBMECs）. A rat model of MCAO was established. EPCs were pretreat⁃ ed with EPCs，HBMECs⁃pEPCs or AMD3100（CXCR4 antagonist），respectively. Cognitive function was assessed by Morris water maze test at week 6，and angiogenesis in cerebral cortex was observed by immunofluorescence staining at week 7. Results EPCs treatment decreased the apoptotic rate of HBMECs induced by OGD（P < 0.05） and increased the number of vascular ring（P < 0.05）. OGD⁃HBMECs induced an increase in SDF⁃1α expression in EPCs，and CXCR4 knockdown alleviated the anti⁃apoptosis effect of EPCs on OGD⁃HBMECs（P < 0.05）. The number of EPCs and vessels with positive Claudin5 and level of SDF⁃1α protein in cerebral cortex of MCAO rats markedly increased on day 4 after the model establishment（P < 0.05）. As compared with EPCs treatment，HBMECs⁃pEPCs treatment significantly increased vascular density（P < 0.05）and improved deficits of learning and memory in the rat model of MCAO，while AMD3100 reversed the therapeutic effect of HBMECs⁃pEPCs. Conclusions HBMECs⁃ pEPCs can effectively promote neurovascular remodeling and cognitive function recovery via SDF⁃1α⁃CXCR4 axis in the rat model of MCAO.

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