目的:低能量雷射治療(low power laser therapy, LLLT)目前常用於臨床治療運動傷害造成的肌腱病變或傷害,然而對於修復肌腱病變的分子生物學機轉尚不明確,因此本研究的目的在於探討以低能量雷射治療對於肌腱細胞分泌膠原蛋白以修復受傷之肌腱,可做為低能量雷射治療肌腱病變之理論基礎。方法:本研究使用大鼠肌腱細胞為實驗模型,來檢視低能量雷射治療(LLLT)對於肌腱細胞分泌膠原蛋白以修復受傷之肌腱,低能量雷射治療波長660奈米,採用連續性模式輸出功率50毫瓦,以不同照射時間產生不同劑量之低能量雷射去處置肌腱細胞,用即時聚合酶鏈鎖反應(real-time PCR)和西方點墨法(western blot analysis)分析基質金屬蛋白酶(matrix metalloproteinases)及膠原蛋白(collagen)的表現量和分泌量。結果:在即時聚合酶鏈鎖反應(real-time PCR),基質金屬蛋白酶-9(matrix metalloproteinases-9)表現量隨著雷射劑量提升而下降,第一型膠原蛋白(type I collagen)表現量在雷射劑量1.0焦耳/平方公分而上升,第三型膠原蛋白(ttype III collagen)表現量隨著雷射劑量提升而上升;在西方點墨法分析中,基質金屬蛋白酶-8(matrix metalloproteinases-8)和基質金屬蛋白酶-9(matrix metalloproteinases-9)分泌量隨著雷射劑量提升而下降,第一型膠原蛋白(type I collagen)表現量在雷射劑量1.0焦耳/平方公分的上升。結論:基質金屬蛋白酶(matrix metalloproteinases-9)表現量和分泌量隨著雷射劑量提升而下降,然而在1.0焦耳/平方公分的雷射劑量下,肌腱細胞的第一型膠原蛋白(type I collagen)表現量和分泌量均上升。
Objective: Low-level laser therapy (LLLT) is commonly used to treat sports-related tendinopathy or tendon injury. However, scientific evidence of the effects and underlying molecular mechanisms of tendinopathy treatment remained limited. Tendon healing requires tenocyte migration to the repair site, followed by proliferation and synthesis of the extracellular matrix, including collagens. The study was designed to determine the effect of laser on the metabolism of collagen for injuried tendon repair, furthermore, become a foundation of the LLLT for tendon repair. Methods: Tendon cells from rat Achilles tendons were obtained to investigate the effect of LLLT on collagen metabolism in tendon repair. LLLT was performed with a 600-nm laser in continuous mode with an output power of 50 mW at different periods with increasing energy densities. Real-time polymerase chain reaction (PCR) and western blot analysis were used to determine the gene expression and production of matrix metalloproteinase (MMP) and collagen. Results: The mRNA expression of MMP-9 was down-regulated by LLLT dose-dependently, the mRNA expression of type I collagen was up-regulated at an energy density of 1.0 J/cm^2, and type III collagen was up-regulated dose-dependently. Densitometry analysis using western blot indicated that protein expression of MMP-8 and MMP-9 was dose-dependently down-regulated by laser treatment and type I collagen was up-regulated at an energy density of 1.0 J/cm^2. Conclusions: LLLT dose-dependently down-regulates the expression of MMP-9 and up-regulates the expressions of type I collagen at an energy density of 1.0 J/cm^2.