title: Low-level laser facilitates alternatively activated macrophage/microglia polarization and promotes functional recovery after crush spinal cord injury in rats.
abstract: Macrophages and resident microglia play an import role in the secondary neuroinflammation response following spinal cord injury. Reprogramming of macrophage/microglia polarization is an import strategy for spinal cord injury restoration. Low-level laser therapy (LLLT) is a noninvasive treatment that has been widely used in neurotrauma and neurodegenerative diseases. However, the influence of low-level laser on polarization of macrophage/microglia following spinal cord injury remains unknown. The present study applied low-level laser therapy on a crush spinal cord injury rat model. Using immunofluorescence, flow cytometry, RT-qPCR, and western blot assays, we found that low-level laser therapy altered the polarization state to a M2 tendency. A greater number of neurons survived in the pare injury site, which was accompanied by higher BBB scores in the LLLT group. Furthermore, low-level laser therapy elevated expression of interleukin 4 (IL-4) and interleukin 13 (IL-13). Results from this study show that low-level laser therapy has the potential for reducing inflammation, regulating macrophage/microglia polarization, and promoting neuronal survival. These beneficial effects demonstrate that low-level laser therapy may be an effective candidate for clinical treatment of spinal cord injury.
authors.affiliation: Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Ji Wei
authors.initials: JW
authors.lastname: Song
authors.affiliation: Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Li
authors.affiliation: Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Zhuo Wen
authors.initials: ZW
authors.lastname: Liang
authors.affiliation: Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Dai
authors.affiliation: Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Xue Feng
authors.initials: XF
authors.lastname: Shen
authors.affiliation: Department of Physics, Institute of Photonics and Photon-Technology, Northwest University, Xi'an, Shaanxi, China.
authors.forename: Yu Ze
authors.initials: YZ
authors.lastname: Gong
authors.affiliation: Department of Physics, Institute of Photonics and Photon-Technology, Northwest University, Xi'an, Shaanxi, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China. huxueyu@fmmu.edu.cn.
authors.forename: Xue Yu
authors.initials: XY
authors.lastname: Hu
authors.affiliation: Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China. wangzhe@fmmu.edu.cn.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D001522:Behavior, Animal; D015415:Biomarkers; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D018836:Inflammation Mediators / Q000378:metabolism; D053685:Laser Therapy / Q000379:methods; D008262:Macrophage Activation / Q000276:immunology*; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D017628:Microglia / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism; D000066829:Neuroprotection; D010641:Phenotype; D051381:Rats; D020127:Recovery of Function / Q000528:radiation effects*; D013119:Spinal Cord Injuries / Q000209:etiology / Q000378:metabolism* / Q000534:rehabilitation* / Q000628:therapy
chemical_list: D015415:Biomarkers; D016207:Cytokines; D018836:Inflammation Mediators