ACETALDEHYDE-MEDIATED BRONCHIAL CILIA DYSFUNCTION

申请者摘要：酗酒者患肺病的几率增加 部分由于肺宿主防御功能改变而引起的疾病 与酒精毒性和酗酒者吸烟的强烈倾向有关 很重。一种主要的呼吸道防御功能在这两种情况下受损 酒精摄入和吸烟是粘液纤毛的清除 系统。粘液纤毛损伤的一种可能机制 酒精摄入和吸烟是乙醛暴露自乙醛 是由肝脏和局部在乙醇代谢过程中产生的 在呼吸道中，在气相中也发现大量的 香烟的烟雾。这一点很重要，因为乙醛是一种高度 活性分子已被认为是一种重要的毒素 与其与反应性共价结合能力有关的生物系统 蛋白质残留物。初步实验已经证明了这一影响 乙醛对支气管上皮细胞纤毛的影响。这些研究 已确定乙醛对纤毛呼吸道有直接毒性 上皮细胞导致纤毛减慢或瘫痪，抑制纤毛动力 ATPase活性，并与对运动至关重要的纤毛蛋白结合 尤其是动力蛋白和微管蛋白。因此，假设： 乙醛与临界纤毛结合损害呼吸道纤毛功能 蛋白质，包括动力蛋白和微管蛋白，遇到的浓度 在饮酒和吸烟期间。为了检验这一假说 提出了以下具体目标：1)评估能力 乙醛与轴膜动力蛋白和微管蛋白结合并损害ATPase 动力蛋白活性。这些实验将测量化学计量比和 竞争乙醛与纯化的乙醛结合及功能损伤 纤毛动力蛋白和微管蛋白。2)阐明致病机理(S) 乙醛结合损害轴丝动力蛋白与肌动蛋白相互作用 微管蛋白和微管。这些实验将检测乙醛的 对动力蛋白促进微管聚合能力的影响 在无细胞系统中转移微管。3)评估重要性 乙醛暴露是纤毛功能障碍的一个原因 暴露在酒精和烟雾中。这些实验将量化 乙醛-蛋白质结合与组织纤毛功能障碍 乙醛蒸气、香烟烟雾和乙醇的体外暴露 在活体内。

APPLICANT'S ABSTRACT: Alcoholics have an increased incidence of pulmonary diseases that are in part due to altered lung host defense functions related to alcohol toxicity and a strong tendency for alcoholics to smoke heavily. A major airway defense function that is impaired during both alcohol ingestion and cigarette smoking is the mucociliary clearance system. One possible mechanism of mucociliary impairment common to both alcohol ingestion and smoking is acetaldehyde exposure since acetaldehyde is produced during the metabolism of ethanol both by the liver and locally in the airways and is also found in significant amounts in the vapor phase of cigarette smoke. This is important because acetaldehyde is a highly reactive molecule that has been recognized as a significant toxin in biologic systems related to its ability to covalently bind to reactive protein residues. Preliminary experiments have demonstrated the influence of acetaldehyde on bronchial epithelial cell cilia. These studies established that acetaldehyde is directly toxic to ciliated airway epithelial cells causing cilia slowing or paralysis, inhibits cilia dynein ATPase activity, and binds to cilia proteins critical for motility especially dynein and tubulin. It is hypothesized, therefore, that: Acetaldehyde impairs airway cilia function by binding to critical cilia proteins, including dynein and tubulin, in concentrations encountered during alcohol ingestion and cigarette smoking. To test this hypothesis the following specific aims are proposed: 1) Assess the ability of acetaldehyde to bind to axonemal dynein and tubulin and impair the ATPase activity of dynein. These experiments will measure stoichiometric and competitive acetaldehyde binding to and functional impairment of purified cilia dynein and tubulin. 2) Elucidate the mechanism(s) by which acetaldehyde binding impairs the interaction of axonemal dynein with tubulin and microtubules. These experiments will examine acetaldehyde's effect on dynein's ability to enhance microtubule polymerization and translocate microtubules in a cell-free system. 3) Assess the importance of acetaldehyde exposure as a cause of cilia dysfunction in the setting of alcohol and smoke exposure. These experiments will quantify acetaldehyde-protein binding and dysfunction in the cilia of tissues exposed to acetaldehyde vapor, cigarette smoke and ethanol both in vitro and in vivo.