title: Low-power laser irradiation inhibits arecoline-induced fibrosis: an in vitro study.
abstract: Oral submucous fibrosis (OSF) is a potentially malignant disorder that is characterized by a progressive fibrosis in the oral submucosa. Arecoline, an alkaloid compound of the areca nut, is reported to be a major aetiological factor in the development of OSF. Low-power laser irradiation (LPLI) has been reported to be beneficial in fibrosis prevention in different damaged organs. The aim of this study was to investigate the potential therapeutic effects of LPLI on arecoline-induced fibrosis. Arecoline-stimulated human gingival fibroblasts (HGFs) were treated with or without LPLI. The expression levels of the fibrotic marker genes alpha-smooth muscle actin (α-SMA) and connective tissue growth factor (CTGF/CCN2) were analysed by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) and western blots. In addition, the transcriptional activity of CCN2 was further determined by a reporter assay. The results indicated that arecoline increased the messenger RNA and protein expression of CCN2 and α-SMA in HGF. Interestingly, both LPLI and forskolin, an adenylyl cyclase activator, reduced the expression of arecoline-mediated fibrotic marker genes and inhibited the transcriptional activity of CCN2. Moreover, pretreatment with SQ22536, an adenylyl cyclase inhibitor, blocked LPLI's inhibition of the expression of arecoline-mediated fibrotic marker genes. Our data suggest that LPLI may inhibit the expression of arecoline-mediated fibrotic marker genes via the cAMP signalling pathway.
authors.affiliation: School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Mei-Chun
authors.initials: MC
authors.lastname: Yeh
authors.affiliation: School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Dentistry, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Ker-Kong
authors.initials: KK
authors.lastname: Chen
authors.affiliation: School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Orthopaedic Research Center, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Min-Hsuan
authors.initials: MH
authors.lastname: Chiang
authors.affiliation: Orthopaedic Research Center, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Physical Medicine and Rehabilitation, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Physical Medicine and Rehabilitation, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chia-Hsin
authors.initials: CH
authors.lastname: Chen
authors.affiliation: School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Ping-Ho
authors.initials: PH
authors.lastname: Chen
authors.affiliation: School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Dentistry, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Huey-Er
authors.initials: HE
authors.lastname: Lee
authors.affiliation: School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Orthopaedic Research Center, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Yan-Hsiung
authors.initials: YH
authors.lastname: Wang
mesh_terms: D000199:Actins / Q000378:metabolism; D001114:Areca; D015153:Blotting, Western; D002470:Cell Survival; D005576:Colforsin / Q000494:pharmacology; D055513:Connective Tissue Growth Factor / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects* / Q000528:radiation effects*; D005881:Gingiva / Q000166:cytology*; D006801:Humans; D066298:In Vitro Techniques; D028022:Low-Level Light Therapy; D009914:Oral Submucous Fibrosis / Q000517:prevention & control*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D000199:Actins; C526317:CCN2 protein, human; D055513:Connective Tissue Growth Factor; D005576:Colforsin