title: Low-level laser irradiation stimulates tenocyte proliferation in association with increased NO synthesis and upregulation of PCNA and cyclins.
abstract: Low-level laser therapy is commonly used to treat tendinopathy or tendon injury. Tendon healing requires tenocyte migration to the repair site, followed by proliferation and synthesis of the extracellular matrix. There are few evidence to elucidate that low-level laser promote tenocyte proliferation. This study was designed to determine the effect of laser on tenocyte proliferation. Furthermore, the association of this effect with secretion of nitric oxide (NO) and the expressions of proliferating cell nuclear antigen (PCNA) and cyclins D1, E, A, and B1 was investigated. Tenocytes intrinsic to rat Achilles tendon were treated with low-level laser (660 nm). Tenocyte proliferation was evaluated by MTT assay and immunocytochemistry with Ki-67 stain. NO in the conditioned medium was measured by ELISA. Western blot analysis was used to evaluate the protein expressions of PCNA and cyclins D1, E, A, and B1. The results revealed that tenocytes proliferation was enhanced dose dependently by laser. NO secretion was increased after laser treatment. PCNA and cyclins E, A, and B1 were upregulated by laser. In conclusion, low-level laser irradiation stimulates tenocyte proliferation in a process that is mediated by upregulation of NO, PCNA, and cyclins E, A, and B1.
authors: Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, Gueishan Township, Taoyuan County, Taiwan.
authors: Wen-Chung
authors: WC
authors: Tsai
authors: Ju-Wen
authors: JW
authors: Cheng
authors: Jean-Lon
authors: JL
authors: Chen
authors: Chen-Yin
authors: CY
authors: Chen
authors: Hsiang-Ning
authors: HN
authors: Chang
authors: Yu-Hsin
authors: YH
authors: Liao
authors: Miao-Sui
authors: MS
authors: Lin
authors: Jong-Hwei S
authors: JH
authors: Pang
mesh_terms: D000125:Achilles Tendon / Q000166:cytology* / Q000187:drug effects / Q000528:radiation effects; D000818:Animals; D015153:Blotting, Western; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D017077:Culture Media, Conditioned / Q000494:pharmacology; D016213:Cyclins / Q000378:metabolism*; D007150:Immunohistochemistry; D028022:Low-Level Light Therapy; D009569:Nitric Oxide / Q000096:biosynthesis*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism*; D017207:Rats, Sprague-Dawley; D015854:Up-Regulation / Q000187:drug effects / Q000528:radiation effects*; D014945:Wound Healing / Q000187:drug effects / Q000528:radiation effects
chemical_list: D017077:Culture Media, Conditioned; D016213:Cyclins; D018809:Proliferating Cell Nuclear Antigen; D009569:Nitric Oxide