Multi-Scale Investigations of Respiratory Mucus/Mucin Structure and Function in Health and Disease

总体摘要 黏液清除系统构成了抵抗吸入性感染的主要呼吸道宿主防御系统。 毒剂和毒素。然而，尽管对粘液清除的性质进行了两个多世纪的研究， 在这一系统中，我们对这一系统基本方面的认识仍然存在着令人惊讶的差距。填补这些空白是 这对于改进公共卫生战略以抗击呼吸道传染病具有重要意义。填补这些空白 对阐明慢性肺部疾病的发病机制和开发治疗方法也很重要， 包括COPD、哮喘、NCFB和罕见的遗传性疾病(CF、PCD)，根据定义，这些疾病的特征是 粘液在肺内堆积。这篇PPG建议研究基本的，但鲜为人知的方面 必须对粘液清除系统进行定量，以了解粘液在健康和功能障碍中的功能 在疾病中。每个PPG项目都有两个具体目标，一个集中在基本粘蛋白功能上，一个集中在 粘蛋白病理生物学的翻译方面。项目1(“呼吸道粘液中的粘蛋白结构和相互作用”， Michael Rubinstein，PhD，PI)将研究溶液中粘蛋白组织的基本方面 在粘液层内。这些研究将得到添加“反常聚合物”的研究的补充， 例如DNA，到粘液溶液。项目2(“为什么粘蛋白如此巨大，切断它们是否安全/有效 Richard C.Boucher，医学博士，PI)将专注于基本问题，即为什么人类呼吸道 粘蛋白聚合物具有如此巨大的尺寸(300mda，Rg 250 nm)，并且表征了功效比(链 用于肺部疾病的粘液剂的开发所需的风险(脱靶链解卷)和风险(长度减少)。 项目3(“呼吸道表面的膜结合粘蛋白确保有效的粘液清除和肺部健康”， Brian Button，PhD，PI)将研究纤毛、PCL和运输所需的粘液层之间的关系， 重点介绍了一种新颖的液压“推动”机构与经典的“抓取”机构。此外，PCL的屏障功能 并对其监管进行研究。项目4(“呼吸道的生物物理和结构特征 《健康和囊性纤维化中的粘膜下腺粘液》，Ronit Freeman，PhD，Pi)将专注于一种新的属性 粘膜下腺(SMG)粘液的一种链/束不溶成分，以及链/束如何起作用 说明SMG粘液在健康和疾病中的作用。支持PPG的三个核心：1)核心A、 管理/生物统计学核心，多PI理查德·C·鲍彻医学博士和迈克尔·鲁宾斯坦博士，用品 PPG的项目管理和统计支持；2)核心B，粘液/粘蛋白分析核心，PI Mehmet Kesimer博士为PPG和新型生化/生物物理提供所有粘蛋白试剂的质量控制 和3)核心C，成像核心，PI Camille Ehre，PhD，提供电子显微镜， 对这些项目进行了分子和形态分析。PPG的总体目标是阐明结构 粘液在健康中的作用，这些特性在疾病中如何降解，并确定应对策略 治疗黏膜阻塞性疾病的新型治疗药物的开发。

OVERALL ABSTRACT The mucus clearance system constitutes the primary airway host defense system against inhaled infectious agents and toxins. However, despite more than two centuries of research into the nature of the mucus clearance system, surprising gaps in our knowledge of fundamental aspects of this system persist. Filling in these gaps is important for improving public health strategies to combat respiratory infectious diseases. Filling in these gaps is also important for elucidating the pathogenesis of and developing therapies for chronic pulmonary diseases, including COPD, asthma, NCFB, and rare genetic diseases (CF, PCD), which are by definition characterized by mucus accumulation in the lung. This PPG proposes to investigate fundamental, but poorly understood, aspects of the mucus clearance system that must be quantitated to understand mucus function in health and dysfunction in disease. Each PPG project has two specific aims focused on basic mucin function and one focused on translational aspects of mucin pathobiology. Project 1 (“Mucin Structure and Associations in Respiratory Mucus”, Michael Rubinstein, PhD, PI) will investigate fundamental aspects of the organization of mucins in solution and within the mucus layer. These studies will be complemented by studies of the addition of “abnormal polymers”, e.g., DNA, to mucus solutions. Project 2 (“Why are mucins so gigantic and is it safe/effective to sever them therapeutically?”, Richard C. Boucher, MD, PI) will focus on the fundamental question as to why human airway mucin polymers are of such enormous size (300 MDa, Rg 250 nm) and characterize the ratio of efficacy (chain length reduction) vs risk (off-target chain unwinding) required for the development of mucolytics for lung disease. Project 3 (“Membrane-bound mucins on the airway surface ensure efficient mucus clearance and lung health”, Brian Button, PhD, PI) will study the relationships between cilia, PCL, and the mucus layer required for transport, focusing on a novel hydraulic “pushing” vs classic “clawing” mechanisms. In addition, barrier functions of PCL and regulation thereof will be studied. Project 4 (“Biophysical and structural characterization of airway submucosal gland mucus in health and cystic fibrosis”, Ronit Freeman, PhD, PI) will focus on a novel attribute of submucosal gland (SMG) mucus, a strand/bundle insoluble component, and how strands/bundles contribute to SMG mucus function in health and disease. Three cores support the PPG: 1) Core A, the Administrative/Biostatistical Core, Multi-PIs Richard C. Boucher, MD, and Michael Rubinstein, PhD, supplies project management and statistical support for the PPG; 2) Core B, the Mucus/Mucin Analytics Core, PI Mehmet Kesimer, PhD, provides quality control of all mucin reagents for the PPG and novel biochemical/biophysical measurements; and 3) Core C, the Imaging Core, PI Camille Ehre, PhD, provides electron microscopic, molecular, and morphologic analyses to the projects. The overall goals of the PPG are to elucidate the structure and function of mucus in health, how these characteristics are degraded in disease, and identify strategies for development of novel therapeutic agents to treat muco-obstructive diseases.