C-X-C chemokine receptor type 7 antibody enhances neural plasticity after ischemic stroke

Stromal cell-derived factor-1 and its receptor C-X-C chemokine receptor 4(CXCR4) have been shown to regulate neural regeneration after stroke.Howeve r,whether stromal cell-derived factor-1 receptor CXCR7,which is widely distributed in the develo ping and adult central nervous system,participates in neural regeneration remains poorly unde rstood.In this study,we established rat models of focal cerebral ischemia by injecting endothelin-1 into the cerebral co rtex and striatum.Starting on day 7 after injury,CXCR7-neutralizing antibody was injected into the lateral ventricle using a micro drug delivery system for 6 consecutive days.Our results showed that CXCR7-neutralizing antibody increased the total length and number of sprouting co rticospinal tra ct fibers in rats with cerebral ischemia,increased the expression of vesicular glutamate transporter 1 and growth-related protein 43,marke rs of the denervated spinal cord synapses,and promoted the differentiation and maturation of oligodendrocyte progenitor cells in the striatum.In addition,CXCR7 antibody increased the expression of CXCR4 in the striatum,increased the protein expression of RAS and ERK1/2 associated with the RAS/ERK signaling pathway,and im proved rat motor function.These findings suggest that CXCR7 improved neural functional recovery after ischemic stroke by promoting axonal regeneration,synaptogenesis,and myelin regeneration,which may be achieved by activation of CXCR4 and the RAS/ERK1/2 signaling pathway.