Repair of Airway Epithelium Following Chlorine Lung Injury

氯肺损伤后气道上皮的修复

• 批准号: 8020447
• 负责人: Gary W. Hoyle
• 金额: $ 26.33万
• 依托单位: UNIVERSITY OF LOUISVILLE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-23 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8020447
• 关键词: Acute; Acute Lung Injury; Affect; Basal Cell; Brain-Derived Neurotrophic Factor; Breathing; Cell Differentiation process; Cell Line; Cell physiology; Cells; Characteristics; Chemicals; Chlorine; Clara cell; Clinical; Coughing; Cultured Cells; Development; Distal; Dyspnea; Epithelial; Epithelial Cells; Epithelium; Exposure to; Fostering; Funding Opportunities; Future; Gases; Goals; Human; Industrial Accidents; Inflammation; Injury; Irritants; Knock-out; Knockout Mice; Laboratories; Life; Ligands; Lung; Measures; Microarray Analysis; Mus; Mutant Strains Mice; NGFR Protein; Natural Disasters; Natural regeneration; Nerve Growth Factor Receptors; Nerve Growth Factors; Neurotrophin 3; Oryctolagus cuniculus; Peptides; Poison; Population; Principal Investigator; Proliferating; Proteins; Protocols documentation; Pseudostratified Epithelium; Pulmonary Edema; Receptor Signaling; Recording of previous events; Research; Resolution; Respiratory System; Respiratory Tract Infections; Respiratory tract structure; Role; Stem cells; Structure of respiratory epithelium; Symptoms; Testing; Therapeutic Agents; Time; Tissues; Toxic effect; Trachea; Tracheal Epithelium; Transgenic Mice; Translational Research; Unconscious State; United States; Wild Type Mouse; airway epithelium; airway obstruction; base; cell type; chemical release; chlorine gas; design; embryonic stem cell; injured; injured airway; lung injury; neurotrophic factor; novel strategies; overexpression; receptor binding; repaired; research study; respiratory; response; restoration; small molecule; stem cell differentiation; therapy development; toxicant; treatment strategy

DESCRIPTION (provided by applicant): Acute high-level exposures to chemicals that damage the respiratory tract can cause life-threatening lung injury. Chlorine gas is a highly toxic respiratory irritant that is considered a chemical threat agent because of the possibility that it could be released in industrial accidents or terrorist attacks. Chlorine, like many pulmonary toxicants, produces injury to epithelial cells lining the respiratory tract. Loss of the respiratory epithelial cell barrier contributes to other sequelae observed in acute lung injury, including pulmonary edema, airway obstruction, inflammation, and respiratory infections. Efficient repair of respiratory epithelium and restoration of barrier function are essential for resolution of chlorine-induced lung injury. The epithelium of the respiratory tract is repaired following injury through the proliferation and differentiation of stem cells. One type of cell involved in the repair of airway epithelium is the basal cell. The low-affinity nerve growth factor receptor (NGFR) has been identified as a marker for basal cells, as well as for epithelial stem cells in other tissues, but the role of this protein in stem cell function is unknown. NGFR binds multiple neurotrophin ligands, including nerve growth factor (NGF), brain-derived neurotrophic factor, and neurotrophin 3. The hypothesis to be tested in the proposed studies is that NGFR controls the proliferation, survival, and differentiation of lung epithelial stem cells following chlorine-induced lung injury. In Specific Aim 1, basal cells will be purified from the trachea of normal mice and from mutant mice lacking functional NGFR. The ability of the cultured cells to survive, proliferate, and differentiate into other types of epithelial cells (ciliated cells and Clara cells) will be measured in the presence or absence of NGFR ligands. In Specific Aim 2, wild-type, NGFR knockout, and NGF transgenic mice will be exposed to chlorine gas according to a protocol established in the Principal Investigator's laboratory. Effects of neurotrophins will be tested by delivering ligands intranasally or by using NGF-overexpressing transgenic mice previously developed in the Principal Investigator's laboratory. The extent of tracheal epithelial repair will be measured at various times after chlorine exposure. In Specific Aim 3, the effect of neurotrophins on epithelial repair following chlorine exposure in rabbits will be investigated. Rabbits will be used for these studies because of the wider distribution of basal cells in the airways in this species which is more similar to that in humans. The proposed experiments will not only investigate mechanisms of epithelial repair, but will also foster the development of therapeutic agents that could be used to stimulate resolution of lung injury following inhalation of toxic chemicals. PUBLIC HEALTH RELEVANCE: This application is submitted in response to PAR-10-019, CounterACT Exploratory/Developmental Projects in Translational Research (R21). The proposed experiments are designed to understand how the lung repairs itself after inhalation of a toxic gas with the goal of developing therapy for lung injury based on stimulating lungs cells to accelerate repair. This type of research is sought through the Funding Opportunity Announcement because of concerns that U. S. civilians could be adversely affected by highly toxic chemicals released intentionally in terrorist attacks or unintentionally in industrial accidents or natural disasters.

描述（由申请人提供）：急性高级暴露于损害呼吸道的化学物质会导致威胁生命的肺损伤。氯气是一种剧毒呼吸道刺激性，被认为是化学威胁剂，因为它有可能在工业事故或恐怖袭击中释放。氯与许多肺有毒物质一样，会对呼吸道内壁的上皮细胞造成损伤。呼吸性上皮细胞屏障的丧失导致急性肺损伤中观察到的其他后遗症，包括肺水肿，气道阻塞，炎症和呼吸道感染。有效修复呼吸道上皮和屏障功能的恢复对于解决氯诱导的肺损伤至关重要。通过干细胞的增殖和分化，在损伤后修复呼吸道上皮。涉及气道上皮修复的一种细胞是基底细胞。低亲和力的神经生长因子受体（NGFR）已被确定为基底细胞的标志物以及其他组织中的上皮干细胞，但是该蛋白质在干细胞功能中的作用尚不清楚。 NGFR结合多种神经营养蛋白配体，包括神经生长因子（NGF），脑衍生的神经营养因子和神经营养蛋白3。在拟议的研究中要检验的假说是NGFR控制着肺部上皮损伤的肺上皮干细胞的增殖，生存和分化。在特定的目标1中，基底细胞将从正常小鼠的气管和缺乏功能性NGFR的突变小鼠中纯化。在存在或不存在NGFR配体的情况下，将测量培养的细胞生存，增殖和分化为其他类型上皮细胞（纤毛细胞和克拉拉细胞）的能力。在特定的目标2中，根据主要研究者实验室中建立的方案，将使野生型​​，NGFR敲除和NGF转基因小鼠暴露于氯气中。神经营养蛋白的作用将通过鼻内或使用先前在主要研究者实验室中开发的过表达NGF的转基因小鼠来测试。气管上皮修复的程度将在氯暴露后的不同时间测量。在特定的目标3中，将研究神经营养蛋白对兔氯暴露后上皮修复的影响。这些研究将使用兔子，因为该物种中基底细胞的分布更大，这与人类更相似。提出的实验不仅将研究上皮修复的机制，而且还将促进治疗剂的发展，这些治疗剂可用于刺激吸入有毒化学物质后刺激肺损伤的分辨率。 公共卫生相关性：该申请是针对PAR-10-019的响应提交的，《转化研究中的探索/发展项目》（R21）。提出的实验旨在了解吸入有毒气体后如何修复肺部，以开发基于刺激肺部细胞加速修复的肺损伤治疗的治疗。由于担心美国在恐怖袭击中有意释放的剧毒化学物质或在工业事故或自然灾害中无意中释放的剧毒化学物质可能会对美国平民产生不利影响，因此通过资助机会公告寻求这种研究。