title: Low-power laser irradiation promotes the proliferation and osteogenic differentiation of human periodontal ligament cells via cyclic adenosine monophosphate.
abstract: Retaining or improving periodontal ligament (PDL) function is crucial for restoring periodontal defects. The aim of this study was to evaluate the physiological effects of low-power laser irradiation (LPLI) on the proliferation and osteogenic differentiation of human PDL (hPDL) cells. Cultured hPDL cells were irradiated (660 nm) daily with doses of 0, 1, 2 or 4 J⋅cm(-2). Cell proliferation was evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, and the effect of LPLI on osteogenic differentiation was assessed by Alizarin Red S staining and alkaline phosphatase (ALP) activity. Additionally, osteogenic marker gene expression was confirmed by real-time reverse transcription-polymerase chain reaction (RT-PCR). Our data showed that LPLI at a dose of 2 J⋅cm(-2) significantly promoted hPDL cell proliferation at days 3 and 5. In addition, LPLI at energy doses of 2 and 4 J⋅cm(-2) showed potential osteogenic capacity, as it stimulated ALP activity, calcium deposition, and osteogenic gene expression. We also showed that cyclic adenosine monophosphate (cAMP) is a critical regulator of the LPLI-mediated effects on hPDL cells. This study shows that LPLI can promote the proliferation and osteogenic differentiation of hPDL cells. These results suggest the potential use of LPLI in clinical applications for periodontal tissue regeneration.
authors.affiliation: Institute of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Jyun-Yi
authors.initials: JY
authors.lastname: Wu
authors.forename: Chia-Hsin
authors.initials: CH
authors.lastname: Chen
authors.forename: Li-Yin
authors.initials: LY
authors.lastname: Yeh
authors.forename: Ming-Long
authors.initials: ML
authors.lastname: Yeh
authors.forename: Chun-Chan
authors.initials: CC
authors.lastname: Ting
authors.forename: Yan-Hsiung
authors.initials: YH
authors.lastname: Wang
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000067956:Adenylyl Cyclase Inhibitors; D000469:Alkaline Phosphatase / Q000032:analysis / Q000235:genetics / Q000528:radiation effects; D000880:Anthraquinones; D055396:Bone Morphogenetic Protein 2 / Q000235:genetics; D002118:Calcium / Q000378:metabolism / Q000528:radiation effects; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000528:radiation effects; D002460:Cell Line; D049109:Cell Proliferation / Q000528:radiation effects; D004396:Coloring Agents; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics; D000242:Cyclic AMP / Q000037:antagonists & inhibitors / Q000528:radiation effects*; D015870:Gene Expression / Q000528:radiation effects; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D054023:Lasers, Semiconductor; D028022:Low-Level Light Therapy / Q000295:instrumentation*; D015675:Osteocalcin / Q000235:genetics; D010012:Osteogenesis / Q000235:genetics / Q000528:radiation effects*; D010513:Periodontal Ligament / Q000166:cytology / Q000528:radiation effects*; D011829:Radiation Dosage; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D000880:Anthraquinones; C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D004396:Coloring Agents; D050659:Core Binding Factor Alpha 1 Subunit; C493709:RUNX2 protein, human; D013778:Tetrazolium Salts; D013844:Thiazoles; D015675:Osteocalcin; C017759:9-(tetrahydro-2-furyl)-adenine; C004468:Alizarin Red S; D000242:Cyclic AMP; D007770:L-Lactate Dehydrogenase; D000469:Alkaline Phosphatase; C022616:thiazolyl blue; D000225:Adenine; D002118:Calcium