| 摘要: | 研究顯示，在許多纖維化疾病中，例如: idiopathic pulmonary fibrosis (IPF)，TGF-β1會刺激肺部纖維母細胞結締組織生長因子（connective tissue growth factor, CTGF）表現。而近年來也有研究指出組蛋白去乙醯化酶（histone deacetylase）在許多纖維化疾病中具有高活性的表現，然而，對於HDAC抑制劑參與肺部纖維化的作用機轉仍不是很清楚。本篇論文將深入探討HDAC抑制劑MPT0G013在TGF-β誘導人類肺部纖維母細胞CTGF表現中所扮演的角色。結果顯示，細胞前處理MPT0G013 (0.01-1 μM) 可以抑制TGF-β誘導人類肺部纖維母細胞(WI-38) CTGF、collagen及α-smooth muscle actin (α-SMA)的表現，而同樣在thrombin、ET-1誘導CTGF的表現也能被抑制。進一步實驗證實以不同濃度MPT0G013 (0.01-1 μM)處理不會影響細胞存活率。此外，MPT0G013可抑制TGF-β所誘導ERK1/2和p38 phosphorylation，但不會影響JNK的磷酸化。亦可以抑制TGF-β所誘導轉錄因子STAT3和Smad3的磷酸化及AP-1、STAT3及Smad3的轉錄活性，但不影響c-jun的磷酸化。另外，我們進一步發現MPT0G013會增加mitogen-activated protein kinase phosphatase (MKP-1)的acetylation。再者，我們也觀察到MKP-1 acetylation可以增加與TGF-β所誘導p38及ERK1/2的結合能力。因此，綜合以上的結果，我們發現在人類肺部纖維母細胞當中，MPT0G013可以藉由增加MKP-1 acetylation來抑制TGF-β誘導的ERK及p38訊息傳遞路徑，進而抑制Smad3、STAT3及AP-1等轉錄活性，導致CTGF表現減少。這些結果顯示G013可以作為發展治療肺部纖維化疾病一個新的治療方針。
In previous study, TGF-β1 could induce connective tissue factor in many fibrotic disease, such as idiopathic pulmonary fibrosis (IPF). Numerous studies also reported that fibrotic proteins such as connective growth factor (CTGF) overproduction in the development of lung fibrosis. Recently, several studies reported that HDAC inhibitor may be a new therapeutic strategy in fibrotic disease. However, the mechanism of HDAC inhibitor in TGF-β-induced fibrotic protein expression is unknown. Our data show that MPT0G013, pan-HDAC inhibitor, suppressing TGF-β-induced CTGF, collagen, and α-SMA expression in human lung fibroblasts (WI-38). Treatment of cells with MPT0G013 also inhibited thrombin- and endothelin-1-induced CTGF expression. MPT0G013 also supressed TGF-β-induced CTGF-luciferase activity. It had no effect on WI-38 cell viability. Moreover, MPT0G013 inhibited TGF-β1-induced increase in phosphorylation of ERK1/2 and p38, but had no effect on JNK phosphorylation. It is also inhibited TGF-β-induced STAT3 and Smad3 phosphorylation and STAT3-、Smad3- and AP-1-luciferase activity, but had no effect on c-jun phosphorylation. In addition, MPT0G013 could induce mitogen-activated protein kinase phosphatase (MKP-1) acetylation, and induced Acyl-MKP-1, p38 and ERK1/2 complex formation. Taken together, these results suggest that MPT0G013 inhibited TGF-β-induced fibrotic protein, and this inhibition is mediated by inducing of MKP-1 acetylation, and then suppressed ERK1/2 and p38 phosphorylated. Our results suggested that MPT0G013 may be a new therapeutic strategy to pulmonary fibrosis. |
