Collagen transcription and lung fibrosis

胶原转录和肺纤维化

• 批准号: 6638816
• 负责人: BARBARA Davis SMITH
• 金额: $ 32.6万
• 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 2005-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6638816
• 关键词: MHC class II antigen; biosynthesis; collagen; genetic regulatory element; genetic transcription; genetically modified animals; immunogenetics; immunotherapy; interferon gamma; laboratory mouse; lung injury; nonhuman therapy evaluation; protein kinase; protein localization; pulmonary fibrosis /granuloma; respiratory disorder chemotherapy; transcription factor

Certain lung injuries induce large increases in connective tissue content, particularly collagen, resulting in fibrosis. During injury, cells are exposed to molecules such as interferon-gamma (IFN-gamma) and transforming growth factor-beta (TGF-beta), regulating production of matrix components. Clinical trials for interstitial pulmonary fibrosis (IPF) are ongoing. However, very little is understood concerning collagen repression by this mediator. This project focuses on establishing the mechanisms by which collagen transcription is repressed by IFN- gamma. We have recently described a regulatory factor for X-box (RFX) binding site at the collagen transcription start site. RFX1 represses collagen transcription. RFX1 interacts with and activates c-Abl, a non- receptor tyrosine kinase that can phosphorylate itself, RFX1 and the carboxyl domain of RNA polymerase II (CTD). C-Abl interacts with RFX1 at the collagen transcription start site. This proposal determines whether c-Abl participates in signal transduction pathways leading to decreased collagen synthesis. RFX5 forms a complex at the collagen transcription start site when RFX1 is removed. IFN-gamma induces class II transcription activator (CIITA) which interacts with RFX5 forming a complex with two other proteins that activate major histocompatibility class II proteins (MHC-II). Since IFN-gamma represses collagen synthesis, we hypothesize that RFX proteins mediate collagen transcription repression during IFN-gamma treatment. Our overall hypothesis is that IFN-gamma repression occurs on the collagen promoter by cooperative interactions of RFX protein family members at the start site with other proteins binding to the proximal promoter. The specific aims are to; 1) Determine the function and interactions of RFX family before and after IFN-gamma treatment. 2) Examine the functional interactions of c-Abl with RFX proteins at the collagen transcription start site. 3) Examine the localization and kinase activity of c-Abl and RFX in lung fibroblasts under different treatments and in samples of human lung tissue. 4) Use transgenic animals with collagen-promoter-CAT constructs or animals deficient in c-Abl or RFX5 complex to investigate collagen transcriptional regulation during fibrosis and treatment.

某些肺部损伤会导致结缔组织含量，尤其是胶原蛋白的大幅增加，从而导致纤维化。在受伤期间，细胞暴露于分子（例如干扰素 - γ（IFN-gamma））和转化生长因子β（TGF-β），从而调节基质成分的产生。间质肺纤维化（IPF）的临床试验正在进行中。但是，关于该调解人的胶原蛋白抑制作用几乎没有理解。该项目着重于建立胶原蛋白转录被IFN-GAMMA抑制的机制。我们最近描述了胶原转录起始位点上X-Box（RFX）结合位点的调节因子。 RFX1抑制胶原蛋白转录。 RFX1与RNA聚合酶II（CTD）的磷酸化，RFX1和羧基域的非受体酪氨酸激酶相互作用并激活C-ABL。 C-ABL在胶原转录起始位点与RFX1相互作用。该建议确定C-ABL是否参与信号转导途径，导致胶原蛋白合成减少。删除RFX1时，RFX5在胶原蛋白转录起始位点形成复合物。 IFN-GAMMA诱导II类转录激活剂（CIITA）与RFX5相互作用，与其他两种激活主要组织相容性II类蛋白（MHC-II）形成复合物。由于IFN-GAMMA抑制胶原蛋白的合成，因此我们假设RFX蛋白在IFN-GAMMA处理过程中介导胶原蛋白转录抑制。我们的总体假设是，IFN-gamma抑制作用发生在胶原蛋白启动子上，这是通过RFX蛋白家族成员在开始部位与其他蛋白质与近端启动子结合的其他蛋白质的合作相互作用。具体目标是； 1）确定IFN-gamma治疗前后RFX家族的功能和相互作用。 2）检查胶原转录起始位点上C-ABL与RFX蛋白的功能相互作用。 3）检查在不同处理和人类肺组织样品中，C-ABL和RFX在肺成纤维细胞中的定位和激酶活性。 4）使用转基因动物与胶原蛋白促销构建体或缺乏C-ABL或RFX5复合物缺乏的动物一起研究纤维化和治疗过程中胶原蛋白的转录调节。