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：
9476314
负责人：
Surafel Mulugeta
金额：
$ 47.03万
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/9476314
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 Exposure to Functional disorder Future Gene Mutation Gene Proteins Gene-Modified Genes Growth Hand Health Homeostasis Human Impairment 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 Transgenic Organisms Treatment Efficacy Validation Variant Work age related alveolar epithelium alveolar lamellar body alveolar type II cell cytotoxicity defined contribution disease phenotype gene interaction in vivo influenzavirus insight lung injury misfolded protein mouse model mutant novel programs 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（由适用提供）：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II型（AT2）细胞中发现ABCA3之后，其对肺部健康和疾病的重要性突显了大量引人入胜的报道将ABCA3的突变与各种肺部疾病联系起来，包括新生儿和年龄较大的儿童和成人的慢性肺部肺部疾病（包括新生儿的致命表面活性剂）。在我们先前表征ABCA3基本细胞生物学的工作的基础上，该项目将使用集成和还原主义方法来定义与肺部的细胞和有机有机后果的机制和途径，这是由两种与人类遗传性肺部疾病相关的两种不同类别的abca3蛋白突变类药物的AT2细胞的表达来表达的。我们已经确定了几种ABCA3突变，这些突变在体外表现出功能性（转运蛋白）或随后诱导的ER应激和细胞毒性的运输缺陷。此外，我们开发了一种新型的转基因敲入（Ki）小鼠模型，该模型表达了ABCA3（ABCA3E292V）最常见的临床变体，该变体会发展为依赖年龄的实质性实质肺重塑。我们的初步数据表明，该功能性ABCA3突变体破坏了细胞大噬菌物，从而通过溶酶体依赖性和与ER应激无关的途径产生细胞毒性。我们的工作模型建议ILD相关的ABCA3突变引起了一类特异性的，不同的AT2细胞反应集，然后驱动异常的肺损伤/重塑。该项目包含三个主题相互关联的特定目的，这些目标涉及对肺部细胞生物学至关重要的新主题：蛋白质质量控制，细胞器稳态和细胞保护。具体的目标1将表征AT2细胞功能障碍的机制，该机制在体内的转运缺陷ABCA3E292V突变体的表达中。具体目标2将研究ABCA3E292V肺对外源性“第二次命中”的脆弱性，并确定伴随ER应力在促进和增强异常肺部重塑中的作用。具体目标3将利用第二种新型ILD的Ki小鼠模型，我们最近开发了表面活性剂蛋白C（SP-C）基因，SP-CI73T的最常见的ILD相关突变，我们最近证明，该突变也严重破坏了包括自噬在内的细胞质量控制。然后，我们将使用这种新型双基因模型，然后评估SP-CI73T共表达在调节ABCA3E292V突变相关病理学中的后果。拟议研究的结果使用AT2细胞中的稀有基因突变作为模型，不仅会增强我们对家族ILD病理生理学基础的分子机制的了解，而且更广泛地促进了对AT2细胞功能障碍的意义的更好理解，从而诱导异常的肺肺重塑，并为未来的针对目标型FibrApies fibradic fibradic fibradic lung fibradic lung fibradic lung fibradic fibradic fibradic lung fibradic fibradic lung。