Department of Orthopaedic Surgery, School of Medicine, Kanazawa University, 13-1 Takaramachi, Kanazawa, 920-8641, Japan.
Lasers Med Sci. 2010 Jul;25(4):531-7. doi: 10.1007/s10103-009-0743-7. Epub 2010 Feb 17.
Irradiation by light emitting diode (LED) promotes fibroblast proliferation and wound healing. However, its mechanism is still unknown. The purpose of this study was to clarify the mechanism of fibroblast proliferation by LED irradiation. Cultured NIH3T3 fibroblasts from normal mice were irradiated by LED with a center wavelength of 627 nm. LED irradiation was performed with an energy density of 4 J/cm(2), at subculture and 24 h later. The expression of several growth factors and their receptors was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR): platelet-derived growth factor (PDGF)-A, PDGF-B, and PDGF-C, transforming growth factor-beta (TGF-beta), basic fibroblast growth factor (bFGF), PDGF-alpha receptor, and TGF-beta receptor. Then, the activation of the extracellular signal-regulated kinase (ERK) pathway was examined by Western blotting with and without the PDGF receptor inhibitor. LED irradiation induced cell growth of NIH3T3 fibroblasts. The expression of PDGF-C had significantly increased in the irradiated group (P < 0.01). Although strong activation of the ERK pathway was observed in the irradiated group, its activation was completely suppressed by the PDGF receptor inhibitor. We concluded that LED irradiation promotes fibroblast proliferation by increasing autocrine production of PDGF-C and activating the ERK pathway through phosphorylation of the PDGF receptor.
发光二极管（LED）照射可促进成纤维细胞增殖和伤口愈合。但其作用机制尚不清楚。本研究旨在阐明 LED 照射促进成纤维细胞增殖的机制。用中心波长为 627nm 的 LED 照射正常小鼠 NIH3T3 成纤维细胞。在传代和 24 小时后，用 4J/cm2 的能量密度进行 LED 照射。通过逆转录-聚合酶链反应（RT-PCR）分析几种生长因子及其受体的表达：血小板衍生生长因子（PDGF）-A、PDGF-B 和 PDGF-C、转化生长因子-β（TGF-β）、碱性成纤维细胞生长因子（bFGF）、PDGF-α 受体和 TGF-β 受体。然后，通过 Western blot 检测有和没有 PDGF 受体抑制剂时细胞外信号调节激酶（ERK）通路的激活情况。LED 照射诱导 NIH3T3 成纤维细胞生长。照射组 PDGF-C 的表达显著增加（P < 0.01）。尽管在照射组中观察到 ERK 通路的强烈激活，但 PDGF 受体抑制剂完全抑制了其激活。我们得出结论，LED 照射通过增加 PDGF-C 的自分泌产生并通过 PDGF 受体的磷酸化激活 ERK 通路来促进成纤维细胞增殖。
