- 學位論文
IL-6刺激人類肺部纖維母細胞結締組織生長因子表現之分子機轉探討
Molecular mechanisms of interleukin-6-induced connective tissue growth factor expression in human lung fibroblasts
摘要
Interleukin-6 (IL-6)可以引發許多跟專一性發炎反應相關蛋白分泌，最後導致及發炎反應的產生。有研究指出，IL-6與肝臟的纖維化也有很大的相關性。最近研究證實CTGF過度表現將會誘導肺部纖維化的發生。而肺部的發炎反應便是肺部纖維化的重要特徵之一。在本篇論文中，我們將探討JAK2和STAT3參與在WI-38纖維母細胞中IL-6誘導CTGF表現。給予AG490 (JAK抑制劑)可依劑量反應關係，抑制IL-6誘導CTGF蛋白的表現。進一步的轉染JAK2 DN和STAT3 DN可降低CTGF的表現量。且發現IL-6可誘導STAT3及p300結合到CTGF promoter上-747到-184片段。由於p300是個相當重要的coactivator，因此我們發現IL-6可藉由造成p300 Ser1834的磷酸化，來增加p300的活性，且進一步的造成STAT3以及histone H3的乙醯化。且當我們轉染p300 siRNA時，會降低IL-6所引起的CTGF表現。因此本篇論文發現IL-6會活化下游的JAK/STAT訊息傳遞路徑，來誘導CTGF的表現，且STAT3也會受p300所調控。本研究的整體目標為釐清IL-6刺激人類纖維母細胞CTGF表現的分子機制，進一步希望能發展肺部纖維化疾病之有效預防與治療的策略。
並列摘要
Several reports indicated that IL-6 can induce protein expression which associated with acute inflammation and fibrogenesis. Recent studies also show that chronic lung inflammation is an important sign of lung fibrosis, and connective tissue growth factor(CTGF) plays an important role in lung fibrosis. In this study, we investgated the involvement of JAK2 and STAT3 in IL-6-induced CTGF expression in WI-38 lung fibroblast. Pretreating WI-38 with AG490, a JAK inhibitor, attenuates IL-6-induced CTGF expression. Furthermore, transfected WI-38 with STAT3 DN and JAK2 DN inhibited IL-6-induced CTGF expression. We also found IL-6-induced STAT3 and p300 binding CTGF promoter form -747 to -184. Because p300 is a very important coactivator that regulated gene expression. We found that IL-6 induced increased in p300 phosphorylation at Ser1834, p300 activity, and STAT3 and histone H3 acetylation. Cells were transfection with p300 siRNA inhibited IL-6-induced CTGF expression. Therefore, we suggest that IL-6 activates JAK2 and STAT3 and p300 signaling pathway which in turns induce CTGF expression. The results of this study will elucidate the molecular mechanism of IL-6-induced CTGF expression and further promote developing an effective therapy of lung fibrosis.