title: A Low-Level Carbon Dioxide Laser Promotes Fibroblast Proliferation and Migration through Activation of Akt, ERK, and JNK.
abstract: BACKGROUND
  Low-level laser therapy (LLLT) with various types of lasers promotes fibroblast proliferation and migration during the process of wound healing. Although LLLT with a carbon dioxide (CO2) laser was also reported to promote wound healing, the underlying mechanisms at the cellular level have not been previously described. Herein, we investigated the effect of LLLT with a CO2 laser on fibroblast proliferation and migration.
  
  
  METHODS
  Cultured human dermal fibroblasts were prepared. MTS and cell migration assays were performed with fibroblasts after LLLT with a CO2 laser at various doses (0.1, 0.5, 1.0, 2.0, or 5.0 J/cm2) to observe the effects of LLLT with a CO2 laser on the proliferation and migration of fibroblasts. The non-irradiated group served as the control. Moreover, western blot analysis was performed using fibroblasts after LLLT with a CO2 laser to analyze changes in the activities of Akt, extracellular signal-regulated kinase (ERK), and Jun N-terminal kinase (JNK), which are signaling molecules associated with cell proliferation and migration. Finally, the MTS assay, a cell migration assay, and western blot analysis were performed using fibroblasts treated with inhibitors of Akt, ERK, or JNK before LLLT with a CO2 laser.
  
  
  RESULTS
  In MTS and cell migration assays, fibroblast proliferation and migration were promoted after LLLT with a CO2 laser at 1.0 J/cm2. Western blot analysis revealed that Akt, ERK, and JNK activities were promoted in fibroblasts after LLLT with a CO2 laser at 1.0 J/cm2. Moreover, inhibition of Akt, ERK, or JNK significantly blocked fibroblast proliferation and migration.
  
  
  CONCLUSIONS
  These findings suggested that LLLT with a CO2 laser would accelerate wound healing by promoting the proliferation and migration of fibroblasts. Activation of Akt, ERK, and JNK was essential for CO2 laser-induced proliferation and migration of fibroblasts.
authors.affiliation: Department of Plastic and Reconstructive Surgery, Juntendo University School of Medicine, Hongo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Shingyochi
authors.affiliation: Department of Plastic and Reconstructive Surgery, Juntendo University School of Medicine, Hongo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Kanazawa
authors.affiliation: Department of Plastic and Reconstructive Surgery, Juntendo University School of Medicine, Hongo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tajima
authors.affiliation: Department of Plastic and Reconstructive Surgery, Juntendo University School of Medicine, Hongo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Rica
authors.initials: R
authors.lastname: Tanaka
authors.affiliation: Department of Plastic and Reconstructive Surgery, Juntendo University School of Medicine, Hongo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mizuno
authors.affiliation: Department of Plastic and Reconstructive Surgery, Juntendo University School of Medicine, Hongo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Morikuni
authors.initials: M
authors.lastname: Tobita
mesh_terms: D002245:Carbon Dioxide; D002465:Cell Movement; D049109:Cell Proliferation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology* / Q000528:radiation effects*; D006801:Humans; D054020:Lasers, Gas; D028022:Low-Level Light Therapy; D048670:MAP Kinase Kinase 4 / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D015398:Signal Transduction; D012867:Skin / Q000378:metabolism
chemical_list: D002245:Carbon Dioxide; C494918:AKT1 protein, human; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases; D048670:MAP Kinase Kinase 4