Alveolar epithelial endoplasmic reticulum (ER)-stress in Idiopathic Pulmonary Fibrosis - identification of molecular trigger events and role in fibrotic repair

特发性肺纤维化中的肺泡上皮内质网 (ER) 应激 - 分子触发事件的识别及其在纤维化修复中的作用

• 批准号: 166385523
• 负责人: Professor Dr. Andreas Günther
• 金额: --
• 依托单位: Medizinische Klinik und Poliklinik II: Pneumologie, Gastroenterologie, Nephrologie und Internistische Intensivmedizin
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/166385523?language=en
• 关键词: Alveolar; epithelial; endoplasmic; reticulum; ER

Chronic epithelial injury has been proposed to underly Idiopathic Pulmonary Fibrosis (IPF), a life-threatening disease with an average survival time of 2-3 years. Our group recently discovered severe, pro-apoptotic ER-stress in alveolar type II cells (AECII). As one underlying reason, we identified defective post-translational processing of surfactant proteins (SP)-B and C, with intracellular accumulation of unprocessed SP as a result of the downregulation of the lysosomal proteases napsin A and cathepsin H. We now aim to: i) proof causality and precisely describe molecular mechanisms underlying the induction of ER stress in vitro and in vivo (overexpression of cleavage resistant variants of proSP-B in vitro, generation of transgenic mice with AECII specific, inducible expression of shRNAs against napsin A and cathepsin H), ii) characterize the transcriptional regulation of cathepsin H and napsin A under conditions of health and disease (reporter gene and silencing assays, chromatin immunoprecipitation studies), iii) to evaluate new therapeutic approaches in IPF, which are centered on the prevention of protein misfolding (application or overexpression of chaperones) or the blockade of the pro-apoptotic, ER-stress derived, transcription factor CHOP.

慢性上皮损伤被认为是特发性肺纤维化(IPF)的基础，IPF是一种威胁生命的疾病，平均生存时间为2-3年。我们小组最近在肺泡II型细胞(AECII)中发现了严重的、促凋亡的内质网应激。作为一个潜在的原因，我们发现了表面活性蛋白(SP)-B和C的翻译后加工缺陷，由于溶酶体蛋白Napsin A和Cathepsin H的下调，导致未加工的SP在细胞内积累。我们现在的目标是：i)证明因果关系并精确描述在体外和体内诱导ER应激的分子机制(体外过表达prosp-B的抗切割变体，产生AECII特异性的转基因小鼠，针对napsin A和cathepsin H的shRNAs的诱导表达)，ii)描述组织蛋白酶H和napsin A在健康和疾病条件下的转录调控(报告基因和沉默分析，染色质免疫沉淀研究)，iii)评估IPF的新治疗方法，这些方法以防止蛋白质错误折叠(应用或过度表达伴侣蛋白)或阻断促凋亡、内质网应激衍生的转录因子CHOP为中心。