title: Irradiation with a low-level diode laser induces the developmental endothelial locus-1 gene and reduces proinflammatory cytokines in epithelial cells.
abstract: We demonstrated previously that low-level diode laser irradiation with an indocyanine green-loaded nanosphere coated with chitosan (ICG-Nano/c) had an antimicrobial effect, and thus could be used for periodontal antimicrobial photodynamic therapy (aPDT). Since little is known about the effects of aPDT on periodontal tissue, we here investigated the effect of low-level laser irradiation, with and without ICG-Nano/c, on cultured epithelial cells. Human oral epithelial cells were irradiated in a repeated pulse mode (duty cycle, 10 %; pulse width, 100 ms; peak power output, 5 W). The expression of the developmental endothelial locus 1 (Del-1), interleukin-6 (IL-6), IL-8, and the intercellular adhesion molecule-1 (ICAM-1) were evaluated in Ca9-22 cells stimulated by laser irradiation and Escherichia coli-derived lipopolysaccharide (LPS). A wound healing assay was carried out on SCC-25 cells irradiated by diode laser with or without ICG-Nano/c. The mRNA expression of Del-1, which is known to have anti-inflammatory activity, was significantly upregulated by laser irradiation (p < 0.01). Concurrently, LPS-induced IL-6 and IL-8 expression was significantly suppressed in the LPS + laser group (p < 0.01). ICAM-1 expression was significantly higher in the LPS + laser group than in the LPS only or control groups. Finally, compared with the control, the migration of epithelial cells was significantly increased by diode laser irradiation with or without ICG-Nano/c. These results suggest that, in addition to its antimicrobial effect, low-level diode laser irradiation, with or without ICG-Nano/c, can suppress excessive inflammatory responses via a mechanism involving Del-1, and assists in wound healing.
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University, 2-11 Suemori-dori, Chikusa-ku, 464-8651, Nagoya, Aichi, Japan.
authors.forename: Takeki
authors.initials: T
authors.lastname: Fujimura
authors.forename: Akio
authors.initials: A
authors.lastname: Mitani
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Fukuda
authors.forename: Makio
authors.initials: M
authors.lastname: Mogi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Osawa
authors.forename: Shinko
authors.initials: S
authors.lastname: Takahashi
authors.forename: Makoto
authors.initials: M
authors.lastname: Aino
authors.forename: Yuki
authors.initials: Y
authors.lastname: Iwamura
authors.forename: Shinichi
authors.initials: S
authors.lastname: Miyajima
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Toshihide
authors.initials: T
authors.lastname: Noguchi
mesh_terms: D002135:Calcium-Binding Proteins; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D015815:Cell Adhesion Molecules; D045744:Cell Line, Tumor; D048271:Chitosan / Q000737:chemistry; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism* / Q000528:radiation effects; D005881:Gingiva / Q000528:radiation effects; D006801:Humans; D007208:Indocyanine Green / Q000737:chemistry; D018836:Inflammation Mediators / Q000378:metabolism*; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D054023:Lasers, Semiconductor / Q000627:therapeutic use*; D028022:Low-Level Light Therapy; D054118:Nanospheres / Q000737:chemistry; D010778:Photochemotherapy; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014945:Wound Healing
chemical_list: D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D015815:Cell Adhesion Molecules; D016207:Cytokines; C110183:EDIL3 protein, human; D018836:Inflammation Mediators; D012333:RNA, Messenger; D018799:Intercellular Adhesion Molecule-1; D048271:Chitosan; D007208:Indocyanine Green