The Biology of the ABCA3 Lipid Transporter in Health and Disease

ABCA3 脂质转运蛋白在健康和疾病中的生物学

基本信息

批准号：
9106971
负责人：
Surafel Mulugeta
金额：
$ 48.25万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-05-01 至 2020-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9106971
关键词：
ABCA3 gene Acute Address Adult Affect Aging Alveolar Anabolism Apoptosis Autophagocytosis Biogenesis Biology Bleomycin Carrier Proteins Cell physiology Cells Cellular biology Characteristics Child Chronic Clinical Cytoprotection Data Defect Development Disease Environmental Risk Factor Event Exhibits Functional disorder Future Gene Mutation Gene-Modified Genes Growth Hand Health Homeostasis Human In Vitro Infant Inflammation Inflammatory Inherited Injury Interstitial Lung Diseases Knock-in Mouse Knowledge Link Lipids Lung Lung diseases Lysosomes Membrane Modeling Molecular Mus Mutation Organelles Oxidative Stress Pathogenesis Pathology Pathway interactions Patients Peptide Signal Sequences Phenotype Phospholipids Play Predisposition Protein Isoforms Proteins Pulmonary Fibrosis Pulmonary Surfactant-Associated Protein C Pump Quality Control Reporting Role Severities Signal Transduction Stress Structure of parenchyma of lung System Testing Therapeutic Transgenic Organisms Validation Variant Work age related alveolar epithelium alveolar lamellar body base cytotoxicity defined contribution disease phenotype gene interaction in vivo influenzavirus insight lung injury mouse model mutant novel programs protein misfolding public health relevance response surfactant surfactant deficiency in infants targeted treatment trafficking

项目摘要

DESCRIPTION (provided by applicant): ABCA3 functions as a lipid and phospholipid transporter and is critical for the biogenesis of lamellar bodies. Following our discovery of ABCA3 in alveolar type II (AT2) cells, its importance to lung health and disease has been highlighted by an abundance of compelling reports linking mutations in ABCA3 to various lung disorders, including fatal surfactant deficiency in newborns and chronic interstitial lung disease (ILD) in older children and adults. Building upon our prior work characterizing the basic cell biology of ABCA3, this project will use both integrative and reductionist approaches to define mechanisms and pathways underlying the cellular and organotypic consequences for the lung from the expression by AT2 cells of two distinct classes of mutant isoforms of ABCA3 proteins associated with inherited lung disorders in humans. We have identified several ABCA3 mutations that in vitro exhibit either functional (transporter) or trafficking defects with the later inducing ER stress and cytotoxicity. Furthermore, we have developed a novel transgenic knock-in (KI) mouse model expressing the most common clinical variant of ABCA3 (ABCA3E292V) that develops age dependent parenchymal lung remodeling. Our preliminary data demonstrate that this functional ABCA3 mutant disrupts cellular macroautophagy, producing cytotoxicity by lysosome-dependent and ER stress-independent pathways. Our working model proposes that ILD-associated ABCA3 mutations elicits a class-specific, distinct set of altered AT2 cell responses which then drives abnormal lung injury/remodeling. This project contains three thematically interrelated specific aims that address emerging themes critical to lung cell biology: protein quality control, organelle homeostasis, and cytoprotection. Specific Aim 1 will characterize the mechanisms underlying AT2 cell dysfunction from expression of the transport-deficient ABCA3E292V mutant in vivo. Specific Aim 2 will study the vulnerability of the ABCA3E292V lung to exogenous "2nd hits", and determine the role of concomitant ER stress in promoting and enhancing abnormal lung remodeling. Specific Aim 3 will utilize a second novel KI mouse model of ILD we recently developed bearing the most common ILD-associated mutation of the surfactant protein C (SP-C) gene, SP-CI73T, which we have recently shown to also profoundly disrupt cellular quality control including autophagy. Using this novel bi-genic model, we will then assess the consequences of SP-CI73T co-expression in modulating ABCA3E292V mutation associated pathology. Results from the proposed studies utilizing rare gene mutations in AT2 cells as models will not only enhance our knowledge of the molecular mechanisms underlying the pathophysiology of familial ILD, but also more broadly promote a better understanding of the significance of AT2 cell dysfunction-induced aberrant lung remodeling and provide strategies for future development of targeted therapies for sporadic lung fibrosis.

描述（由申请人提供）：ABCA3 充当脂质和磷脂转运蛋白，对于层状体的生物发生至关重要。在我们在 II 型肺泡 (AT2) 细胞中发现 ABCA3 后，它对肺部健康和疾病的重要性已被强调。大量令人信服的报告将 ABCA3 突变与各种肺部疾病联系起来，包括新生儿致命的表面活性剂缺乏和年龄较大的儿童和成人的慢性间质性肺病 (ILD)。该项目将使用综合和还原论方法来确定 AT2 细胞表达两种不同类别的 ABCA3 蛋白突变亚型对肺产生细胞和器官型影响的机制和途径，这些影响与 ABCA3 蛋白的基本细胞生物学有关。我们已经鉴定出几种 ABCA3 突变，这些突变在体外表现出功能性（转运蛋白）或运输缺陷，并随后诱导内质网应激和细胞毒性。此外，我们还开发了一种新型转基因药物。我们的初步数据表明，这种功能性 ABCA3 突变体会破坏细胞巨自噬，通过溶酶体依赖性和内质网应激产生细胞毒性。我们的工作模型提出，ILD 相关的 ABCA3 突变会引发一组特定的、独特的 AT2 细胞反应改变，从而导致肺部异常。该项目包含三个主题相关的具体目标，解决对肺细胞生物学至关重要的新兴主题：具体目标 1 将通过体内转运缺陷型 ABCA3E292V 突变体的表达来表征 AT2 功能障碍细胞的机制。具体目标 2 将研究 ABCA3E292V 肺对外源“第二次打击”的脆弱性。，并确定伴随的 ER 应激在促进和增强异常肺重塑中的作用。具体目标 3 将利用第二种新型 KI 小鼠 ILD 模型。我们最近开发出带有最常见的 ILD 相关突变的表面活性剂蛋白 C (SP-C) 基因 SP-CI73T，我们最近使用这种新型双基因模型证明，它也会严重破坏细胞质量控制，包括自噬。然后，我们将评估 SP-CI73T 共表达在调节 ABCA3E292V 突变相关病理学中的影响。利用 AT2 细胞中罕见基因突变作为模型的研究结果不仅将增强我们对潜在分子机制的了解。家族性 ILD 的病理生理学，同时也更广泛地促进对 AT2 细胞功能障碍诱导的异常肺重塑的重要性的更好理解，并为未来开发散发性肺纤维化的靶向治疗提供策略。