Regulation of wound healing by granulocyte-macrophage colony-stimulating factor after vocal fold injury.
OBJECTIVE
Vocal fold (VF) scarring remains a therapeutic challenge. Granulocyte-macrophage colony-stimulating factor (GM-CSF) facilitates epithelial wound healing, and recently, growth factor therapy has been applied to promote tissue repair. This study was undertaken to investigate the effect of GM-CSF on VF wound healing in vivo and in vitro.


METHODS
VF scarring was induced in New Zealand white rabbits by direct injury. Immediately thereafter, either GM-CSF or PBS was injected into the VFs of rabbits. Endoscopic, histopathological, immunohistochemical, and biomechanical evaluations of VFs were performed at 3 months post-injury. Human vocal fold fibroblasts (hVFFs) were cultured with GM-CSF. Production of type I and III collagen was examined immunocytochemically, and the synthesis of elastin and hyaluronic acids was evaluated by ELISA. The mRNA levels of genes related to ECM components and ECM production-related growth factors, such as HGF and TGF-ß1, were examined by real time RT-PCR.


RESULTS
The GM-CSF-treated VFs showed reduced collagen deposition in comparison to the PBS-injected controls (P<0.05). Immunohistochemical staining revealed lower amounts of type I collagen and fibronectin in the GM-CSF-treated VFs (P<0.05 and P<0.01, respectively). Viscous and elastic shear moduli of VF samples were significantly lower in the GM-CSF group than in the PBS-injected group (P<0.001 and P<0.01, respectively). Mucosal waves in the GM-CSF group showed significant improvement when compared to the PBS group (P = 0.0446). GM-CSF inhibited TGF-β1-induced collagen synthesis by hVFFs (P<0.05) and the production of hyaluronic acids increased at 72 hours post-treatment (P<0.05). The expressions of HAS-2, tropoelastin, MMP-1, HGF, and c-Met mRNA were significantly increased by GM-CSF, although at different time points (P<0.05).


CONCLUSIONS
The present study shows that GM-CSF offers therapeutic potential for the remodeling of VF wounds and the promotion of VF regeneration.
Department of Otorhinolaryngology-Head and Neck Surgery, Inha University School of Medicine, Incheon, Republic of Korea. jylim@inha.ac.kr
Jae-Yol
JY
Lim
Byung Hyune
BH
Choi
Songyi
S
Lee
Yun Ho
YH
Jang
Jeong-Seok
JS
Choi
Young-Mo
YM
Kim
D000818:Animals; D002478:Cells, Cultured; D024042:Collagen Type I / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D024061:Collagen Type III / Q000235:genetics / Q000378:metabolism; D004549:Elastin / Q000235:genetics / Q000378:metabolism; D005109:Extracellular Matrix / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005353:Fibronectins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism / Q000494:pharmacology*; D017228:Hepatocyte Growth Factor / Q000235:genetics / Q000378:metabolism; D006801:Humans; D006820:Hyaluronic Acid / Q000096:biosynthesis; D015552:Injections, Intralesional; D011817:Rabbits; D053773:Transforming Growth Factor beta1 / Q000235:genetics / Q000378:metabolism; D014827:Vocal Cords / Q000187:drug effects* / Q000293:injuries* / Q000378:metabolism; D014945:Wound Healing / Q000187:drug effects* / Q000502:physiology
D024042:Collagen Type I; D024061:Collagen Type III; D005353:Fibronectins; D053773:Transforming Growth Factor beta1; D017228:Hepatocyte Growth Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006820:Hyaluronic Acid; D004549:Elastin