Epithelial abnormalities in IPF: role of ER stress and GRP78/BiP

IPF 中的上皮异常：ER 应激和 GRP78/BiP 的作用

基本信息

批准号：
8711552
负责人：
Beiyun Zhou
金额：
$ 40.3万
依托单位：
UNIVERSITY OF SOUTHERN CALIFORNIA
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-08-01 至 2018-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8711552
关键词：
Acetylcysteine Address Alveolar Antioxidants Apoptosis Binding Bone Marrow Cell Line Cells Cicatrix Data Deposition Disease Dose Endoplasmic Reticulum Environment Epithelial Epithelial Cells Epithelium Etiology Extracellular Matrix Fibroblasts Fibrosis Functional disorder Generations Goals Hamman-Rich syndrome Homeostasis In Vitro Injury Interstitial Lung Diseases Knock-out Knockout Mice Lead Link Lung Lung diseases Mediating Mediator of activation protein Membrane Mesenchymal Modeling Molecular Molecular Chaperones Mus Mutation Myofibroblast Oxidative Stress Pathogenesis Pathway interactions Phenotype Play Predisposition Process Proteins Pulmonary Fibrosis Pulmonary Surfactant-Associated Protein C Reactive Oxygen Species Reporting Respiratory physiology Role Signal Transduction Tissues Wound Healing age related alveolar epithelium biological adaptation to stress cell injury clinically relevant effective therapy endoplasmic reticulum stress fibrogenesis glucose-regulated proteins in vivo inhibitor/antagonist injured insight monolayer mutant new therapeutic target novel overexpression pneumocyte prevent protein degradation protein folding protein misfolding public health relevance response sensor src-Family Kinases surfactant treatment strategy

项目摘要

DESCRIPTION (provided by applicant): Idiopathic pulmonary fibrosis/usual interstitial pneumonia (IPF/UIP) is a devastating interstitial lung disease of unknown etiology, characterized by (myo)fibroblast activation/proliferation, extracellular matrix (ECM) deposition and progressive lung destruction. A central role for alveolar epithelium in IPF/UIP pathogenesis has recently been postulated. In this paradigm, injured alveolar epithelial cells (AEC) actively participate in fibrogenesis by releasing fibroproliferative mediators that promote proliferation an differentiation of fibroblasts that in turn induce AEC apoptosis and/or giving rise directly to fibroblasts through epithelial-mesenchymal transition (EMT). However, mechanisms underlying AEC injury/activation and downstream molecular pathways linking epithelial abnormalities to fibrosis remain unclear. Association between endoplasmic reticulum (ER) stress and both sporadic and familial pulmonary fibrosis associated with surfactant protein (SP) mutations has been reported. We recently found that ER stress triggers protective signaling known as the unfolded protein response (UPR) and induces both apoptosis and EMT in AEC in vitro via activation of the non-receptor membrane-associated tyrosine kinase Src, supporting a causal role for ER stress in the dysfunctional AEC phenotype in pulmonary fibrosis. Preliminary data suggest that reactive oxygen species (ROS) and b-catenin activation/interaction with the co-activator CBP are involved in Src-dependent signaling. The ER chaperone glucose-regulated protein 78 (GRP78) is a master regulator of ER homeostasis and thus represents an ideal target with which to modulate ER stress responses in alveolar epithelium. The overall goals of this proposal are to investigate mechanisms underlying ER stress-induced epithelial abnormalities implicated in the pathogenesis of fibrosis by modulating GRP78 utilizing mice with lung epithelial cell-specific deletion of Grp78. We hypothesize that (1) loss of Grp78 induces and/or exacerbates experimental fibrosis in vivo; (2) GRP78 insufficiency-induced epithelial injury contributes to fibrosis via direct effects on the epithelium (e.g., apoptosis/EMT) and/or abnormal epithelial-fibroblast crosstalk; and, (3) effects of GRP78 insufficiency on EMT/fibrosis are mediated via Src and/or ROS-dependent ¿-catenin/CBP signaling. We will use AEC-specific Grp78 knockout mice, in conjunction with clinically relevant mutant SP-C¿exon4, our well- established primary AEC in vitro monolayer model, and ICG-001, a novel inhibitor of ¿-catenin/CBP interaction, to address the following Specific Aims: 1. Evaluate effects of ER stress mediated by loss of Grp78 on pulmonary fibrosis in inducible AEC-specific Grp78 knockout mice; 2. Investigate the role of ER stress in AEC abnormalities (apoptosis vs EMT vs aberrant epithelial-fibroblast crosstalk) implicated in fibrosis in inducible AEC-specific Grp78 knockout mice; and 3. Determine mechanisms underlying ER stress-induced AEC injury/fibrosis. These studies will provide insights into mechanisms underlying the pathogenesis of IPF and facilitate identification of novel therapeutic targets for this incurable disease.

描述（由适用提供）：特发性肺纤维化/常规间质性肺炎（IPF/UIP）是一种毁灭性的未知病因学间质肺疾病，其特征是（MyO）成纤维细胞激活/增殖，细胞外矩阵（ECM）（ECM）沉积和进步lung Lung Lung Destruct。最近假设肺泡上皮在IPF/UIP发病机理中的核心作用。在这种范式中，受伤的肺泡上皮细胞（AEC）通过释放纤维增生的介质来积极参与纤维发生，从而促进增生的成纤维细胞的分化，而成纤维细胞的分化又诱导了AEC凋亡和/或直接通过上皮 - 质膜过渡到成纤维细胞引起成纤维细胞。但是，将上皮异常与纤维化联系起来的AEC损伤/激活和下游分子途径的机制尚不清楚。据报道，内质网应激与零星和家族性肺纤维化之间的关联与潜在蛋白（SP）突变有关。我们最近发现，ER应力触发了被称为展开蛋白反应（UPR）的信号传导，并通过激活非受体膜相关的酪氨酸激酶SRC来诱导AEC的凋亡和EMT，从而支持了在纯AEC AEC中的侵蚀作用，从而支持了应激在Pulluctunctunctiund AEC中的应激作用。初步数据表明，活性氧（ROS）和B-catenin激活/与共激活因子CBP的相互作用参与SRC依赖性信号传导。 ER伴侣葡萄糖调节的蛋白78（GRP78）是ER稳态的主要调节剂，因此代表了调节肺泡上皮中ER应力反应的理想靶标。该提案的总体目标是研究通过调节使用GRP78的肺上皮细胞特异性缺失的GRP78使用的GRP78使用的GRP78，在纤维化发病机理中实现了纤维化发病机理的基础机制。我们假设（1）GRP78的丧失会在体内诱导和/或加剧实验性纤维化；（2）GRP78不足引起的上皮损伤通过直接影响上皮（例如凋亡/EMT）和/或异常上皮细胞成纤维细胞串扰而导致纤维化；（3）GRP78不足对EMT/纤维化的影响是通过SRC和/或依赖ROS依赖性的 - Catenin/CBP信号传导介导的。我们将使用AEC特异性的GRP78敲除小鼠，并结合临床相关的突变体SPCCOON4，我们已建立了良好的主要AEC体外单层模型和ICG-001，以及一种新型的`` - catenin/cbp相互作用''的新型抑制剂ICG-001，以解决以下特定目标：1。效果：1。效果。 AEC特异性GRP78淘汰小鼠； 2。研究ER应激在AEC异常中的作用（凋亡与EMT与异常上皮成纤维细胞串扰）在诱导型AEC特异性GRP78敲除小鼠中实施的纤维化中实现的作用；和3。确定ER应力诱导的AEC损伤/纤维化的基础机制。这些研究将提供有关IPF发病机理的机制的见解，并促进对这种无法治愈的疾病的新型治疗靶标的鉴定。