藉由MMP-3-GFP 基因轉殖小鼠及MMP-3-Luc-GFP 大鼠探討 MMP-3 在矯正性牙齒移動的表現

Abstract

先前的研究指出矯正力會增加牙周組織基質金屬蛋白酶MMP-3的表現，然而MMP-3的產生對應矯正施力時間的關係尚不清楚。本實驗使用MMP-33-GFP基因轉殖小鼠及MMP-3-Luciferase-GFP基因轉殖大鼠，以綠螢光蛋白（GFP）作為報導基因，利用觀察切片的綠螢光，來標定MMP-3在矯正施力、及力量移除後表現的時間與空間。本實驗也用免疫組織染色及免疫螢光染色觀察牙周組織 MMP-3、GFP、Luciferase以及CD68的分佈。另外也觀察由轉殖基因大鼠分離的關節腔滑液纖維母細胞受刺激後產生的綠螢光來驗證大鼠GFP的光學性質。本研究發現綠螢光蛋白訊號在牙齒施力後12小時開始出現、一天之後訊號明顯，移除矯正力後三小時還可見綠螢光表現、但八小時後就回到未施力狀態。免疫染色的結果也顯示顯示類似的結果。本實驗以動物模型證明牙齒在受到間歇性矯正力時，牙周組織確實有時間性的訊息傳遞活化及消退。

Matrix metalloproteinase-3 has been reported to be involved in orthodontic tooth movements. But the time frame of the expression of MMP-3 and orthodontic force has not been elucidated. By observing the green flourscent protein (GFP) reporter expression in MMP3-GFP transgenic mice and MMP3- Luciferase-GFP transgenic rats, we can study the temporal and spatial expression of MMP-3 during and after the removal of orthodontic force. The immunohistochemical and immunoflourscent data addressed the distribution of MMP-3, GFP, Luciferase and CD68 around periodontal tissue. The optical property of GFP was detected on synovial fibroblast isolated from the transgenic rat. This research shows that the reporter GFP appears after 12 hours of orthodontic force, and becomes obvious after 1 day. Upon removal of force, the fluorescence signal remained 3 hours after removal of orthodontic force. Nevertheless, it dropped back to baseline after 8 hours. The results of IHC and IF also confirmed this notion. In this study, we demonstrate the time frame of molecular signal activation and quiescence of MMP-3 around periodontal tissue in rodent models using interrupted orthodontic forces.