Collagen Transcription and Lung Fibrosis

胶原蛋白转录和肺纤维化

• 批准号: 6980463
• 负责人: BARBARA Davis SMITH
• 金额: $ 40.38万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6980463
• 关键词: MHC class II antigen; collagen; fibrogenesis; gene induction /repression; gene mutation; genetic transcription; genetically modified animals; immunotherapy; inflammation; interferon gamma; laboratory mouse; lung injury; nonhuman therapy evaluation; protein biosynthesis; protein localization; protein protein interaction; pulmonary fibrosis /granuloma; transcription factor; transforming growth factors

DESCRIPTION (provided by applicant): Certain lung injuries induce large increases in connective tissue content, particularly collagen, resulting in pulmonary fibrosis. During injury, inflammation, and repair, cells are exposed to molecules such as interferon-gamma (IFN-gamma) and transforming growth factor-beta (TGF-beta) that are released by inflammatory cells and regulate production of collagen. Collagen type I transcription is activated after inflammatory response to injury in order to repair damage. This process is followed by repression of transcription. Without transcriptional repression, progressive fibrosis results in the lung. We hypothesize that changes in transcription require multiple proteins interacting cooperatively to alter transcription and chromatin structure in response to cytokine signals. During the last funding period, we focused on the mechanism of IFN-gamma induced repression of collagen transcription. IFN-gamma increases expression of regulatory factor for X-box 5 (RFX5) complex proteins which localizes in the nucleus, interacts with the collagen gene transcriptional start site and represses collagen synthesis. Class II transactivator (CIITA) dramatically increases early during IFN-gamma treatment and interacts with RFX5 complex. IFN-gamma-induced CIITA protein is responsible for both activation of major histocompatibility complex (MHC) and repression of collagen gene expression. Clinical trials for interstitial pulmonary fibrosis with IFN-gamma have been unsuccessful due to increased inflammatory response. We hypothesize that RFX5/CIITA proteins may be responsible for activating inflammatory responses while repressing collagen through separate CIITA transactivation and repression domains. We have compelling evidence that many proteins including co-repressors bind to the collagen start site during repression. Activation by agents such as TGF-beta may recruit different proteins to the collagen gene. The specific aims are to; 1) Determine the proteins interacting with the collagen start site during IFN-gamma treatment. 2) Examine the functional interactions of activation proteins binding upstream in the promoter with RFX family of proteins with and without TGF-beta. 3) Examine bleomycin induced fibrosis in animals with CIITA mutations and/or deficiencies with and without collagen-promoter-CAT constructs to investigate inflammation and collagen transcriptional regulation during fibrosis.

描述（由申请人提供）：某些肺部损伤会引起结缔组织含量，尤其是胶原蛋白的大量增加，导致肺纤维化。 在受伤，炎症和修复过程中，细胞暴露于分子（例如干扰素 - γ（IFN-GAMMA））和通过炎症细胞释放并调节胶原蛋白产生的生长因子β（TGF-β）。 I型胶原蛋白转录在对损伤的炎症反应后被激活以修复损伤。此过程之后是对转录的抑制。没有转录抑制，进行性纤维化会导致肺部。 我们假设转录的变化需要多种蛋白质相互作用以改变转录和染色质结构，以响应细胞因子信号。 在最后一个资金期间，我们专注于IFN-GAMMA诱导胶原蛋白转录的机理。 IFN-GAMMA增加了X-Box 5（RFX5）复合蛋白的调节因子的表达，该蛋白位于细胞核中，与胶原基因转录起始位点相互作用并抑制胶原蛋白合成。 II类反式激活因子（CIITA）在IFN-GAMMA治疗期间早期大幅增加，并与RFX5复合物相互作用。 IFN-GAMMA诱导的CIITA蛋白是主要组织相容性复合物（MHC）的激活和胶原蛋白基因表达的抑制。 由于炎症反应增加，与IFN-GAMMA的间质肺纤维化的临床试验失败了。 我们假设RFX5/CIITA蛋白可能负责激活炎症反应，同时通过单独的CIITA反式激活和抑制域抑制胶原蛋白。 我们有令人信服的证据表明，许多蛋白质在抑制期间都结合了胶原蛋白起始位点。诸如TGF-beta之类的药物的激活可能会募集不同的蛋白质到胶原蛋白基因。 具体目标是； 1）确定在IFN-gamma处理过程中与胶原蛋白起始位点相互作用的蛋白质。 2）检查启动子中与带有TGF-β的RFX家族在启动子上游结合的激活蛋白的功能相互作用。 3）检查具有和/或缺陷的动物中博来霉素诱导的纤维化具有和/或缺乏胶原蛋白促促促促促促进行发电蛋白的纤维蛋白，以研究纤维化过程中的炎症和胶原蛋白转录调节。