Nifedipine經由TGF-β訊息傳導路徑誘導人類口腔上皮細胞LOXL2之表現

Abstract

Nifedipine 是常見的高血壓用藥，副作用是會引起牙齦腫大，造成口腔衛生維護不易，導致牙周病的形成，嚴重時會影響病人的美觀與發音。目前Nifedipine 引起牙齦腫大的致病機制尚未完全了解。離氨基氧化酶樣蛋白 2 (Lysyl oxidase-like 2, LOXL2)為離氨基氧化酶（LOX）家族的成員，近期研究指出，LOXL2 不僅參與細胞外基質的穩定，還可誘導上皮細胞的上皮間質轉化（epithelial mesenchymal transition, EMT），牙齦過度增生。本研究探討Nifedipine 是否會誘導人類牙齦上皮細胞 OECM-1 及 Ca9-22 產生 LOXL2，以及與EMT相關之機轉。結果發現，隨著 Nifedipine 處理的濃度或時間增加可使人類口腔上皮細胞 Ca9-22、OECM-1 的 LOXL2 的表現量隨之增加，且 Nifedipine 可使 Ca9-22、OECM-1 的上皮標誌因子中 E-cadherin 下降，間質標誌因子 Vimentin 及轉化因子 Slug 上升，顯示可以產生EMT 的現象。以 LOXL2 的抑制劑 LOX2-in-1 處理，可以抑制 EMT 的現象。進一步發現TGF-β 可以誘導 Ca9-22、OECM-1 產生 LOLX2，且使用 TGF-β 路徑的抑制劑（TGF-β 中和抗體、SIS3、SB431542）處理 Ca9-22、OECM-1 以後，可有效抑制 Nifedipine 誘導的LOXL2 產生。薑黃素（Curcumin）濃度到達 5μM 時，開始顯著降低 Ca9-22 及 OECM-1 中Nifedipine 誘導的 LOXL2 產生量，並具有劑量依賴效應。本實驗結果及連結先前實驗室的研究，Nifedipine 可活化 TGF-β 路徑，進而促進 LOXL2 表現，最終誘導 EMT 的發生。此外，實驗結果觀察到薑黃素能夠減少 LOXL2 的產生，可以預期薑黃素能抑制 Nifedipine 造成之牙齦腫大，成為新型防治 Nifedipine 導致牙齦增生的治療方法之一。

Nifedipine is a commonly prescribed antihypertensive medication. However, studies have shown that it can induce gingival overgrowth (GO), making oral hygiene maintenance difficult and potentially leading to the development of periodontal disease. In severe cases, this condition may affect aesthetics and speech. The pathogenic mechanism underlying Nifedipine-induced GO remains incompletely understood. Lysyl oxidase-like 2 (LOXL2), a member of the lysyl oxidase (LOX) family, has recently been implicated not only in extracellular matrix stabilization but also in the induction of epithelial-mesenchymal transition (EMT) and GO. This study investigated whether Nifedipine induces LOXL2 expression and EMT-related changes in human gingival epithelial cell lines OECM-1 and Ca9-22. The results demonstrated that Nifedipine increases LOXL2 expression in a dose- and time-dependent manner in both cell lines. Additionally, Nifedipine treatment led to decreased expression of the epithelial marker E-cadherin and increased expression of mesenchymal markers Vimentin and Slug, indicating the occurrence of EMT. Notably, treatment with the LOXL2 inhibitor, LOX2-in-1, effectively suppressed EMT. Furthermore, TGF-β was found to induce LOXL2 expression in both Ca9-22 and OECM-1 cells. Inhibition of the TGF-β signaling pathway using a neutralizing antibody, SIS3, or SB431542 significantly reduced LOXL2 levels. Curcumin, a natural compound known for its anti-inflammatory properties, was shown to decrease Nifedipine-induced LOXL2 expression in a dose-dependent manner, with significant inhibition observed at concentrations as low as 5 μM. Together with our previous findings, these results suggest that Nifedipine activates the TGF-β pathway, which in turn promotes LOXL2 expression and induces EMT in gingival epithelial cells. Moreover, curcumin may serve as a promising therapeutic agent fopreventing Nifedipine-induced gingival overgrowth through the suppression of LOXL2 expression.