Photobiomodulation Therapy Inhibit the Activation and Secretory of Astrocytes by Altering Macrophage Polarization

Cell Mol Neurobiol. 2020 Jan;40(1):141-152. doi: 10.1007/s10571-019-00728-x. Epub 2019 Aug 24.


Spinal cord injury (SCI) stimulates reactive astrogliosis and the infiltration of macrophages, which interact with each other at the injured area. We previously found Photobiomodulation (PBM) significantly decreases the number of M1 macrophages at the injured area of SCI. But the exact nature of the astrocyte response following PBM and relationship with the macrophage have not been explored in detail. In this study, a BALB/c mice model with standardized bilateral spinal cord compression and a macrophage-astrocyte co-culture model were applied to study effects of PBM on astrocytes. Results showed that PBM inhibit the expression of the astrocyte markers glial fibrillary acidic protein (GFAP) and the secretion of chondroitin sulfate proteoglycans (CSPG) in the para-epicenter area, decrease the number of M1 macrophage in vivo. The in vitro experiments indicated M1 macrophages promote the cell viability of astrocytes and the expression of CSPG. However, PBM significantly inhibited the expression of GFAP, decreased activation of astrocyte, and downregulated the expression of CSPG by regulating M1 macrophages. These results demonstrate that PBM may regulate the interaction between macrophages and astrocytes after spinal cord injury, which inhibited the formation of glial scar.

Keywords: Astrocyte; Chondroitin sulfate proteoglycans; Macrophage; Photobiomodulation; Spinal cord injury.

MeSH terms

  • Animals
  • Astrocytes / drug effects
  • Astrocytes / radiation effects*
  • Cell Polarity / drug effects
  • Cell Polarity / radiation effects*
  • Cell Proliferation / drug effects
  • Cell Proliferation / radiation effects
  • Chondroitin Sulfate Proteoglycans / metabolism
  • Culture Media, Conditioned / pharmacology
  • Female
  • Glial Fibrillary Acidic Protein / metabolism
  • Low-Level Light Therapy*
  • Macrophages / drug effects
  • Macrophages / radiation effects*
  • Mice, Inbred BALB C
  • Motor Activity / drug effects
  • Motor Activity / radiation effects
  • Phosphorylation / drug effects
  • Phosphorylation / radiation effects
  • Recovery of Function / drug effects
  • STAT3 Transcription Factor / metabolism
  • Spinal Cord Injuries / physiopathology
  • Spinal Cord Injuries / radiotherapy


  • Chondroitin Sulfate Proteoglycans
  • Culture Media, Conditioned
  • Glial Fibrillary Acidic Protein
  • STAT3 Transcription Factor