title: Effect of diode laser on proliferation and differentiation of PC12 cells.
abstract: This study investigated the effects of diode (GaAlAs) laser irradiation at an effective energy density of 5 or 20 J/cm(2) on cell growth factor-induced differentiation and proliferation in pheochromocytoma cells (PC12 cells), and whether those effects were related to activation of the p38 pathway. Laser irradiation at 20 J/cm(2) significantly decreased the number of PC12 cells, while no difference was seen between the 5 J/cm(2) group and the control group (p<0.05). Western blotting revealed marked expression of neurofilament and β-tubulin, indicating greater neurite differentiation in the irradiation groups than in the control group at 48 hr. Irradiation also enhanced expression of phospho-p38. The decrease in number of cells after laser irradiation was accelerated by p38 inhibitor, while neurite differentiation was up-regulated by laser irradiation, even when the p38 pathway was blocked. This suggests that laser irradiation up-regulated neurite differentiation in PC12 cells involving p38 and another pathway.
authors.affiliation: Department of Endodontics and Clinical Cariology, Tokyo Dental College. ksaito@tdc.jp
authors.forename: Kensuke
authors.initials: K
authors.lastname: Saito
authors.forename: Sadamitsu
authors.initials: S
authors.lastname: Hashimoto
authors.forename: Han-Sung
authors.initials: HS
authors.lastname: Jung
authors.forename: Masaki
authors.initials: M
authors.lastname: Shimono
authors.forename: Kan-Ichi
authors.initials: K
authors.lastname: Nakagawa
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000528:radiation effects; D049109:Cell Proliferation / Q000528:radiation effects; D054023:Lasers, Semiconductor; D028022:Low-Level Light Therapy; D020935:MAP Kinase Signaling System / Q000502:physiology; D020932:Nerve Growth Factor / Q000494:pharmacology; D009416:Nerve Regeneration / Q000528:radiation effects*; D016501:Neurites / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D016900:Neurofilament Proteins / Q000096:biosynthesis; D016716:PC12 Cells / Q000528:radiation effects; D051381:Rats; D014404:Tubulin / Q000096:biosynthesis; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: D016900:Neurofilament Proteins; D014404:Tubulin; D020932:Nerve Growth Factor; D048051:p38 Mitogen-Activated Protein Kinases