title: GM-CSF inhibits glial scar formation and shows long-term protective effect after spinal cord injury.
abstract: OBJECTIVE
  This study investigated the effects of granulocyte macrophage-colony stimulating factor (GM-CSF) on the scar formation and repair of spinal cord tissues in rat spinal cord injury (SCI) model.
  
  
  METHODS
  Sprague-Dawley male rats (8 weeks old) were randomly divided into the sham-operated group, spinal cord injury group, and injury with GM-CSF treated group. A spinal cord injury was induced at T9/10 levels of rat spinal cord using a vascular clip. GM-CSF was administrated via intraperitoneal (IP) injection or on the dural surface using Gelfoam at the time of SCI. The morphological changes, tissue integrity, and scar formation were evaluated until 4 weeks after SCI using histological and immunohistochemical analyses.
  
  
  RESULTS
  The administration of GM-CSF either via IP injection or local treatment significantly reduced the cavity size and glial scar formation at 3-4 weeks after SCI. GM-CSF also reduced the expression of core proteins of chondroitin sulfate proteoglycans (CSPGs) such as neurocan and NG2 but not phosphacan. In particular, an intensive expression of glial fibriallary acidic protein (GFAP) and neurocan found around the cavity at 4 weeks was obviously suppressed by GM-CSF. Immunostaining for neurofilament (NF) and Luxol fast blue (LFB) showed that GM-CSF preserved well the axonal arrangement and myelin structure after SCI. The expression of GAP-43, a marker of regenerating axons, also apparently increased in the rostral grey matter by GM-CSF.
  
  
  CONCLUSIONS
  These results suggest that GM-CSF could enhance long-term recovery from SCI by suppressing the glial scar formation and enhancing the integrity of axonal structure.
authors.affiliation: Department of Neurosurgery, Inha University College of Medicine, Incheon, Republic of Korea.
authors.forename: Xian
authors.initials: X
authors.lastname: Huang
authors.forename: Jin-Mo
authors.initials: JM
authors.lastname: Kim
authors.forename: Tae Ho
authors.initials: TH
authors.lastname: Kong
authors.forename: So Ra
authors.initials: SR
authors.lastname: Park
authors.forename: Yoon
authors.initials: Y
authors.lastname: Ha
authors.forename: Moon Hang
authors.initials: MH
authors.lastname: Kim
authors.forename: Hyeonseon
authors.initials: H
authors.lastname: Park
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Yoon
authors.forename: Hyung Chun
authors.initials: HC
authors.lastname: Park
authors.forename: Jong Oon
authors.initials: JO
authors.lastname: Park
authors.forename: Byoung-Hyun
authors.initials: BH
authors.lastname: Min
authors.forename: Byung Hyune
authors.initials: BH
authors.lastname: Choi
mesh_terms: D000818:Animals; D001369:Axons / Q000187:drug effects / Q000473:pathology; D011508:Chondroitin Sulfate Proteoglycans / Q000378:metabolism; D002921:Cicatrix / Q000473:pathology / Q000517:prevention & control*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D005911:Gliosis / Q000188:drug therapy* / Q000473:pathology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D017628:Microglia / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013119:Spinal Cord Injuries / Q000188:drug therapy* / Q000473:pathology
chemical_list: D011508:Chondroitin Sulfate Proteoglycans; D005904:Glial Fibrillary Acidic Protein; D016178:Granulocyte-Macrophage Colony-Stimulating Factor