環孢素誘導牙齦纖維母細胞表現結締組織生長因子機制之研究

Abstract

牙齦增生是指牙齦上皮組織或結締組織的細胞不正常的過度增殖，使牙齦組織呈現擴大的狀態，根據組織學的特徵可分為炎性增生、纖維性增生或兩者合併。結締組織生長因子(connective tissue growth factor, CTGF/CCN2)是一種間質蛋白，屬於CCN家族的一員，在牙齦增生的組織中常可偵測到結締組織生長因子的上升，且其表現量與牙齦纖維化增生的程度呈正相關。環孢素(cyclosporin A, CsA)是一種免疫抑制劑，這種藥物與抗癲癇藥物phenytoin以及鈣離子阻斷劑常會造成牙齦增生的副作用。我們利用初級培養正常的牙齦纖維母細胞，以反轉錄聚合酶連鎖反應以及西方墨點法觀察環孢素是否能誘發結締組織生長因子的表現。並加入各種天然化學預防藥劑與抑制劑，探討植物生化素對環孢素誘發結締組織生長因子表現的影響。結果發現，環孢素會誘導人類牙齦纖維母細胞表現結締組織生長因子，經環孢素刺激的人類牙齦纖維母細胞，其結締組織生長因子的表現會在2小時達到高峰。JNK和Smad3的抑制劑(SP600125, SIS3)也會抑制環孢素誘導人類牙齦纖維母細胞表現結締組織生長因子。兒茶素(epigallocatechin gallate, EGCG)會抑制環孢素誘導人類牙齦纖維母細胞表現結締組織生長因子，且抑制效果具有濃度依賴性。未來仍需進一步的實驗來確認兒茶素在環孢素引起的牙齦增生中的抑制角色。

Gingival overgrowth is clinically manifested by increased gingival volume, including an increased number of cells and a higher level of extracellular matrix production. Histologically, it can be inflammatory and/or fibrous. Connective tissue growth factor(CTGF/CCN2) is a matricellular protein of the CCN protein family. It is overexpressed in both drug-induced and non-drug-induced gingival overgrowth tissues and is positively related to the degree of fibrosis. Cyclosporin A(CsA) is a selective immunosuppressant that has a variety of applications in medical practice. Like phenytoin and calcium channel blockers, the drug is associated with gingival overgrowth. In this study, human gingival fibroblasts(HGFs) were obtained from normal gingiva and were primary cultured in vitro. CsA-induced CTGF expression were assessed by quantitative reverse transcription polymerase chain reaction and Western blot analysis. Effects of natural chemopreventive drugs and inhibitors of various signaling pathways on CsA-induced CTGF expression were also investigated The results showed that CsA increased CTGF synthesis and that CTGF expression reached the maximal level after 2 hours exposure to CsA. Pretreatment with c-Jun NH2-terminal kinase(JNK) inhibitor SP600125 and SIS3 significantly reduced CsA-induced CTGF expression in HGFs. In addition, EGCG dose-dependently inhibited CsA-induced CTGF expression in HGFs. Additional research is required to confirm the inhibiting role of EGCG in the development of gingival overgrowth.