Role of macrophage polarization in repair of nervous system injury

As one of the most important immune cells in the body, macrophage not only eliminates the foreign matter and accelerates wound healing, but also polarizes itself to the M1 or M2 phenotype as a result of local microenvironment effect. The M1 phenotype macrophage exacerbates nervous system injury, while the M2 phenotype promotes regeneration of nerve system structure and function after injury. In order to better understand the role of macrophage polarization in the course of nervous system injury, this review attempts to explore macrophage from the four aspects: the source of macrophage and its polarization, role of macrophage polarization in nerve injury repair, effect of age factor in macrophage polarization in the nerve injury repair and effect of artificial regulation on macrophage polarization in nerve injury repair. Key words: Nervous system; Macrophages; Repair