title: Increased cell proliferation and differential protein expression induced by low-level Er:YAG laser irradiation in human gingival fibroblasts: proteomic analysis.
abstract: Erbium-doped yttrium aluminum garnet (Er:YAG) laser treatment has demonstrated favorable wound healing effect after periodontal therapy. One of the reasons may be the positive biological effect of the low-level laser on the irradiated tissues, although the mechanism remains unclear. The aim of this study was to investigate the effect of low-level Er:YAG laser irradiation on cell proliferation and laser-induced differential expression of proteins in human gingival fibroblasts (HGFs) by proteomic analysis. In the first experiment, HGFs were exposed to low-level Er:YAG laser irradiation and the laser-induced cell proliferation and damage were evaluated on day 3. In the second experiment, proteomic analysis was performed on day 1 after irradiation. The peptides prepared from HGFs were analyzed by a hybrid ion trap-Fourier transform mass spectrometer, Mascot search engine, and UniProtKB database. A significant increase in cell proliferation without cell damage after irradiation was observed. Among the total identified 377 proteins, 59 proteins, including galectin-7, which was associated with the process of wound healing, were upregulated and 15 proteins were downregulated in laser-treated HGFs. In the third experiment, the increase in messenger RNA (mRNA) and protein expression of galectin-7 in the irradiated HGFs was validated by various analytical techniques. In addition, the effect of recombinant human galectin-7 on the modulation of HGFs proliferation was confirmed. The results indicate that low-level Er:YAG laser irradiation can promote HGF proliferation and induce a significant change in protein expression and the upregulation of galectin-7 expression may partly contribute to the increase in cell proliferation.
authors.affiliation: Department of Periodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Ogita
authors.forename: Sachio
authors.initials: S
authors.lastname: Tsuchida
authors.forename: Akira
authors.initials: A
authors.lastname: Aoki
authors.forename: Mamoru
authors.initials: M
authors.lastname: Satoh
authors.forename: Sayaka
authors.initials: S
authors.lastname: Kado
authors.forename: Masanori
authors.initials: M
authors.lastname: Sawabe
authors.forename: Hiromi
authors.initials: H
authors.lastname: Nanbara
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Koji
authors.initials: K
authors.lastname: Mizutani
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Fumio
authors.initials: F
authors.lastname: Nomura
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Izumi
mesh_terms: D049109:Cell Proliferation / Q000528:radiation effects*; D002478:Cells, Cultured; D005347:Fibroblasts / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D037161:Galectins / Q000494:pharmacology; D015870:Gene Expression / Q000528:radiation effects; D005881:Gingiva / Q000473:pathology; D006801:Humans; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D028022:Low-Level Light Therapy; D010518:Periodontitis / Q000378:metabolism / Q000532:radiotherapy; D020543:Proteome / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics
chemical_list: D037161:Galectins; C092525:LGALS7 protein, human; D020543:Proteome