Remote ischemic postconditioning ameliorates stroke injury via the SDF-1α/CXCR4 signaling axis in rats

Remote Ischemic Postconditioning (RIPostC) has become a research hotspot due to its protective effect on the brain in clinical studies related to ischemic stroke. The purpose of this study is to investigate the protective effect of RIPostC after ischemic stroke in rats. The middle cerebral artery occlusion/reperfusion (MCAO/R) model was established by the wire embolization method. RIPostC was obtained by inducing temporary ischemia in the hind limbs of rats. First, based on the results of short-term behavioral measures and long-term neurological function experiments, RIPostC was found to have a protective effect on the MCAO/R model and to improve neurological recovery in rats. Compared to the sham group, RIPostC upregulated the expression levels of C-X-C motif chemokine receptor 4(CXCR4) in the brain and stromal cell-derived factor-1(SDF-1α) in peripheral blood. In addition, RIPostC upregulated CXCR4 expression on CD34 + stem cells in peripheral blood in flow cytometric assays. Meanwhile, according to the results of EdU/DCX co-staining and CD31 staining, it was found that the effect of RIPostC on ameliorating brain injury via SDF-1α/CXCR4 signaling axis may be associated with vascular neogenesis. Finally, after inhibiting the SDF-1α/CXCR4 signaling axis using AMD3100(Plerixafor), we found that the neuroprotective effect of RIPostC was diminished. Taken together, RIPostC can improve neurobehavioral damage induced by MCAO/R in rats, and its mechanism may be related to SDF-1α/CXCR4 signaling axis. Therefore, RIPostC can be used as an intervention strategy for stroke. SDF-1α/CXCR4 signaling axis can also be a potential target for intervention.