In addition to the poor regenerative ability of neurons,the local microenvironment is not conducive to the regeneration of injured nerves following spinal cord injury (SCI).Neuroinflammation is the most important pathological process affecting the local microenvironment,and infiltrating peripheral macrophages and spinal microglia (macrophage/microglia) are the major effector cells (Burda et al.,2014;Gensel et al.,2015).