基質金屬蛋白酶-3 基因啟動子- 基因轉殖小鼠及基因轉殖大鼠對矯正機械性刺激之表現

Abstract

基質金屬蛋白酶3 ( MMP-3 )和許多基質代謝的生理現象有關。當細胞受到機械力刺激時, 會對MMP-3進行調控。雖然矯正的力量也屬於機械力的一種, 而對於矯正力刺激和MMP-3之間的關係並不明確。為進一步研究MMP-3受到矯正力刺激後在生物體中骨質代謝所扮演的角色, 本實驗室開發帶有MMP-3啟動子的基因轉殖小鼠及基因轉殖大鼠, 藉由動物實驗觀察螢光或冷光的報導基因表現, 進一步瞭解生物體內MMP-3受到刺激後的變化。 本次實驗分做兩部分, 第一部分的實驗中, 利用放置矯正裝置於基因轉殖動物口中, 給予門齒及大臼齒不同方向的矯正力,並於不同的觀察時間點分析報導基因螢光或冷光訊號的改變, 了解MMP-3啟動子活化產生報導基因的時間及作用的位置。 實驗結果顯示, 牙齒受到矯正力的刺激後, 在第一天會出現綠螢光或冷光的表現 , 而在第三天時, 表現並不明顯。就出現螢光出現的位置來看, 綠螢光在張力側較壓力側明顯, 因此MMP-3在細胞受到機械力刺激後, 作用在第一天時上升, 在第三天時開始下降, 顯示MMP-3表現的時間短暫, 在骨質代謝初期時反應。 另一部分, 則是用佐劑誘導關節炎, 建立關節炎之疾病大鼠模型。在關節炎的動物實驗中, 以佐劑誘導後, 冷光在第2天時有明顯上升, 之後緩慢下降, 此冷光訊號雖然受到背景值影響, 但仍能分辨出病程中的變化。由冷光的表現中, 也顯示MMP-3表現在初期發炎反應。因本次實驗觀察的時間較短, 因此, 此動物模型仍待進一步的測試。

Matrix metalloproteinase-3 (MMP-3) participates in many biological activities including turnover of extracellular matrix. Cells, while under mechanical force, can regulate MMP-3 expression. However, the relationship between orthodontic force and MMP-3 expression is still unclear. To further understand the regulation of MMP-3 by the orthodontic force in vivo, we generated transgenic mice and rats with reporter genes of GFP or luciferase under the regulation of MMP-3 promoter. We can detect MMP-3 expression patterns through visualizing the changes of the fluorescent or luminescent signals. In the first part of the experiments, we used different orthodontic appliances in transgenic mice/rats and applied different direction of the orthodontic forces to the incisors and molars. At different time points, we monitored the changes of the fluorescent or luminescent signals. The results show that the fluorescence and luminescence became stronger via orthodontics force application after one day. The intensity was higher at the tension side. The results implied that MMP-3 was turned on at very early stages of the bone metabolism and lasted for a relatively short period of time. In the second part of the experiments, we used adjuvant to induce arthritis (AIA) in transgenic rats. The intensity of the luminescence increased at the second day after induction, and gradually decreased till 2 weeks. Though with some background problems, MMP-3 was stimulated strongly at very early stage of inflammation. More experiments are required to study using this transgenic rat as an arthritis animal model.