低能量雷射對類骨母細胞之影響

Abstract

低能量雷射能加快骨代謝速率，在臨床逐漸普及，但其影響的機制尚不 明朗，也未能制定出明確的參數設定及臨床指引。為探討不同參數設定對類 骨母細胞的影響，本研究使用 660 nm、830 nm、980 nm 二極體雷射，1、 5、10、20 J/cm2 之能量密度每天照射 MG-63 細胞株，以未照雷射者為控制 組，比較各條件下細胞增生及分化的差異。比較各組增生的差異;並在照射 後第一及第三天以 qPCR 比較 Runx2、HIF-1α、VEGFA、ALPL、IBSP 之基因 表現量。結果發現在增生方面，逐日照射後第五天以 alamarBlue 測量，促進 效果最好的參數設定為 830 nm、5 J/cm2，細胞活性比起控制組約多了 60.4%;分化方面，照射後第一天各基因表現皆與控制組無顯著差異，而逐 日照射三天後，對相關基因表現影響最大的條件是 980 nm、1 J/cm2，能增加 108% Runx2 基因表現(p<0.001)、增加 101% VEGFA 表現(p<0.001)，HIF-1α 及 ALPL 的表現量無顯著差異，而 IBSP 無論實驗組與控制組皆無表現。雷射 參數為應用的重點，本實驗係少數設計嚴謹、能跨參數比較的研究，針對雷 射影響骨母細胞的時機提供更多資訊。本研究觀察照射低能量雷射對類骨母 細胞增生及分化的影響。發現在特定雷射參數設定下，確實能有效促進類骨 母細胞的增生及早期分化。

Low-level laser therapy has been shown to accelerate bone remodeling during orthodontic tooth movement, yet the mechanism of its action and proper parameters for clinical use remain unclear. To evaluate the effect of low-level laser on osteoblasts, we had MG-63 cell line exposed to low-level laser irradiation with different wavelengths and energy densities included 660, 830, and 980 nm combined with 1, 5, 10, 20 J/cm2; we compared their proliferation activities with dark control via alamarblue assay, and measured the gene expression of Runx2, HIF-1α, VEGFA, ALPL, and IBSPwith qPCR.In the proliferation assay, after five consecutive days of irradiation, the group irradiated with 830 nm 5 J/cm2low-level laser had increased the most in cell viability(60.4% more than the dark control). In the differentiation assay, there’s no difference in expression between groups after a single exposure. However, after three consecutive days of irradiation, 980 nm 1 J/cm2 laser irradiationhad upregulated the genes the most: 108% increase in Runx2 expression(p<0.001) and 101% increase in VEGFA (p<0.001). There was no difference in HIF-1α or ALPL expression, and IBSP was not expressed at all in both experimental and control groups.Our study was one of the few that provided information comparing between different parameters, with which may determine the effect of laser on cells. In our study, we investigated the effect of low-level laser irradiation on osteoblasts, and found that with specificparameters at certain wavelength, it canaccelerate the cell proliferation and promote early differentiation. In the future, irradiationprotocols should be optimized to modulate specific biological response.