Understanding how alveolar epithelial cell stress drives aberrant repair in interstitial lung disease

了解肺泡上皮细胞应激如何驱动间质性肺疾病的异常修复

基本信息

批准号：
10636819
负责人：
Jeremy Binder Katzen
金额：
$ 16.79万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-01 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10636819
关键词：
Address Adult Air Sacs Alveolar Alveolitis Alveolus Apoptosis Apoptotic Automobile Driving Autophagocytosis Bioinformatics Cell Culture Techniques Cell Line Cell Proliferation Cell model Cells Cellular Stress Cellular biology Child Chronic Disease Coupled Coupling Data Defect Development Disease Disease model Epithelial Cells Epithelium Fibrosis Functional disorder Gene Mutation Generations Genes Genetic Human In Vitro Induced Mutation Inflammation Injury Interstitial Lung Diseases Knock-in Knock-in Mouse Link Lung Lung diseases Mesenchymal Mesenchyme Modeling Molecular Mus Mutate Mutation Organoids Pathogenesis Pathologic Pathway interactions Patients Phenotype Play Pre-Clinical Model Prognosis Proliferating Protein Isoforms Proteins Publishing Pulmonary Fibrosis Pulmonary Pathology Pulmonary Surfactant-Associated Protein C Research Respiratory Failure Role Signal Pathway Signal Transduction System Techniques Therapeutic Therapeutically Targetable Training alveolar epithelium biological adaptation to stress citrate carrier endoplasmic reticulum stress fibrotic interstitial lung disease fibrotic lung disease human disease in vivo in vivo Model inhibition of autophagy injury and repair interstitial lung injury lung repair mouse model multimodality mutant novel patient subsets pharmacologic pre-clinical progenitor programs repaired segregation stem cell function stem cells surfactant theories therapeutic evaluation trafficking transcriptome sequencing

项目摘要

PROJECT SUMMARY Interstitial lung diseases (ILDs) are a class of pulmonary diseases pathologically defined by interstitial fibrosis and inflammation. Owing to our limited understanding of the upstream initiators of pathogenesis, ILDs have poor prognoses and limited therapeutics. Mutations in the Alveolar Epithelial Type 2 Cell (AEC2) restricted Surfactant Protein C (SP-C) gene (SFTPC) in a subset of ILD patients supports a growing hypothesis that AEC2 dysfunction is a driver of disease. When we model these disease-related SFTPC mutations in vitro they segregate into two major classes based upon how the mutated SP-C isoform stresses cellular pathways that manage abnormal proteins: mutations that inhibit macroautophagy and mutations that cause endoplasmic reticulum (ER) stress. However, how these AEC2 stress phenotypes, which have also been identified in ILD patients without SFTPC mutations, relate to ILD development remains poorly understood. To understand this relationship, we have generated two unique Sftpc mutation knock-in mouse models, one expressing an SP-C isoform that induces AEC2 macroautophagy dysfunction (SP-CI73T) and the other inducing ER stress (SP-CC121G). Each of these mutations when expressed in the adult mouse lung results in spontaneous alveolitis and lung injury followed by aberrant repair with resultant fibrotic ILD. These models thus provide proof of concept that AEC2 stress is capable of driving spontaneous lung pathology and are robust preclinical platforms. These models also support a second emerging theory of ILD pathogenesis: that in ILD AEC2s, which must act as critical facultative progenitor cells after lung injury by both proliferating and differentiating to repair damaged epithelium, develop dysfunction in their progenitor cell capacity. We discovered that while similar lung pathology develops in each of our Sftpc models, there are divergent AEC2 proliferation phenotypes following lung injury: SP-CI73T AEC2s become hyperpoliferative and SP-CC121G AEC2s become apoptotic and hypoproliferative. Thus, our models support the hypothesis that abnormal AEC2 progenitor cell function plays a central role in ILD development, and also create a platform to develop a mechanistic understanding of how discrete AEC2 stress signatures result in distinct defects in progenitor cell capacity. This proposal has three interrelated aims that seek to understand the molecular and cellular mechanisms that relate AEC2 cell stress, dysfunctional progenitor cell capacity, and ILD. Aim 1 uses bioinformatics and in vivo linage-tracing to characterize the AEC2 stress signaling and progenitor function pathways involved in each model. Aim 2 provides a mechanistic link between cell stress signaling and progenitor cell dysfunction through ex vivo organoid culture and in vivo modeling. In Aim 3 we will generate the first ILD patient-derived iPSC culture model of an ER stress associated SFTPC mutation as a humanized platform to study the pathways identified in Aims 1 and 2. This proposal will also provided the trainee with the diverse and comprehensive training necessary to develop a multimodal independent research program on the role of the epithelium in ILD.

项目摘要间质性肺部疾病（ILD）是一类肺部疾病，该肺部疾病是由间质纤维化定义的和炎症。由于我们对发病机理上游启动者的有限理解，ILD的不良预后和有限的治疗剂。肺泡上皮2型细胞（AEC2）的突变受限的表面活性剂 ILD患者子集中的蛋白C（SP-C）基因（SFTPC）支持AEC2的越来越多的假设功能障碍是疾病的驱动力。当我们在体外对这些与疾病相关的SFTPC突变进行建模时基于突变的SP-C同工型如何将细胞途径分离为两个主要类别管理异常蛋白质：抑制大噬细胞的突变和引起内质的突变网状（ER）应力。但是，这些AEC2应力表型如何在ILD中也被鉴定没有SFTPC突变的患者与ILD发育有关的患者仍然了解不足。为了了解这种关系，我们已经生成了两个独特的SFTPC突变敲击鼠标模型，一个表达诱导AEC2大型自源功能障碍（SP-CI73T）的SP-C同工型，另一个诱导 ER应力（SP-CC121G）。在成年小鼠肺中表达的每一个突变会自发产生肺泡炎和肺损伤，然后进行异常修复，并导致纤维化ILD。这些模型因此提供了证明 AEC2应力能够驱动自发肺病理并且是稳健的临床前的概念平台。这些模型还支持第二种新兴的ILD发病机理理论：在ILD AEC2S中，该理论肺损伤后必须充当关键的兼职祖细胞，通过增殖和区分以修复上皮受损，其祖细胞能力的功能障碍。我们发现虽然肺类似病理学在我们的每个SFTPC模型中都会发展，有不同的AEC2增殖表型以下肺损伤：SP-CI73T AEC2S变得过度固定，SP-CC121G AEC2S变成了凋亡和低增生性。因此，我们的模型支持以下假设：异常AEC2祖细胞函数扮演A 在ILD发展中的核心作用，还创建了一个平台，以对如何建立机械理解离散的AEC2应力特征会导致祖细胞容量的不同缺陷。该提议具有三个相互关联的目的，试图了解分子和细胞机制将AEC2细胞应激，功能失调的祖细胞能力和ILD相关联。 AIM 1使用生物信息学和体内在每个涉及的AEC2应力信号传导和祖细胞函数途径中表征的线路跟踪模型。 AIM 2通过离体器官培养和体内建模。在AIM 3中，我们将生成第一个ILD患者来源的IPSC ER应力相关的SFTPC突变的文化模型作为研究途径的人源化平台在目标1和2中确定。该提案还将为实习生提供多样化和全面的开发有关上皮在ILD中作用的多模式独立研究计划所需的培训。