Molecular mechanisms for E-cigarette vapor-induced mucociliary dysfunction: role of nicotinic acetylcholine and TRP receptors

使用电子烟（电子烟），被称为“vaping”，正在被青少年广泛采用， 被它们的新奇、合成风味和降低毒性的信念所吸引。以前的吸烟者也使用电子烟作为 一种戒烟工具，是一种替代尼古丁输送系统，社会耻辱感较轻。然而，在这方面， “vaping”是一个新出现的公共卫生问题，特别是对于没有吸烟史的年轻人， 由于缺乏对电子烟蒸汽成分的信息性呼吸研究。既往吸入尼古丁研究 研究了它主要对气道平滑肌和中枢神经系统的影响， 纤毛气道上皮是吸入电子烟蒸汽的主要屏障，很少有研究调查尼古丁在 烟草烟雾成分的分离。此外，大多数电子烟香料的毒理学研究从未 完成吸入暴露。这项研究计划，它的两倍作为一个指导博士后培训， 计划，旨在阐明电子烟蒸汽对功能性人纤毛气道上皮的影响。 气道上皮细胞表达烟碱乙酰胆碱受体（nAChRs）的几种亚型，短暂性 受体电位（TRP）阳离子通道成员A1（TRPA 1）和其他TRP通道，它们都是钙离子通道。 (Ca2+）-渗透。据报道，尼古丁刺激nAChRs和TRPA 1，一些电子烟口味是TRP 激动剂，如肉桂醛（TRPA 1）、香草醛（TRPV 1）和薄荷醇（TRPM 8）。基本假设 该建议的一个重要方面是电子烟蒸汽成分尼古丁和肉桂醛损害粘膜纤毛， 通过刺激nAChR和TRPA 1来引起持续的Ca 2+内流。本研究的研究目标 目的是确定电子烟蒸气如何损害粘膜纤毛功能的分子机制，并开发新的 用于建立体外连续粘膜纤毛转运的高通量方法。后者将用于 以探测雾化化合物的不利/治疗作用。这些目标将在初级人类中进行测试 支气管上皮细胞在气液界面分化，使用生理相关的暴露，和 测量粘液纤毛功能的体外参数，例如粘液纤毛运输、纤毛搏动和气道 表面水合作用本建议的培训目标是发展研究肺效应的专业知识， 吸入有毒物质，并通过在由以下人员组成的多元化团队中工作，沉浸在转化研究中 临床医生和科学家。 本研究的完成将满足未满足的澄清和关于 吸入尼古丁和电子烟香料使用相关的暴露和原代培养将提供一个令人信服的 调整公共卫生政策的生物学原理。它还将告知临床医生电子烟的“利弊”， 戒烟工具，以及对年轻的从不吸烟的受试者采取“vaping”的影响。最后， 完成这一培训计划将产生必要的数据和专业知识， 从博士后实习生到独立调查员

Use of e-cigarettes (E-cigs), known as “vaping”, is becoming widely adopted amongst adolescents who are attracted by their novelty, synthetic flavors, and belief of reduced toxicity. Previous smokers also use E-cigs as a smoking cessation tool that is an alternative nicotine delivery system with milder social stigma. However, “vaping” is an emerging public health problem, especially concerning young people with no smoking history, due to the lack of informative respiratory studies on E-cig vapor components. Past inhaled nicotine studies examined its effects mainly on airway smooth muscle and the central nervous system as opposed to the ciliated airway epithelia, the major barrier for inhaled E-cig vapor, and few studies investigated nicotine in isolation of tobacco smoke constituents. Additionally, toxicology studies of most E-cig flavorings were never completed for inhalation exposure. This research proposal, which doubles as a mentored postdoctoral training plan, aims to elucidate effects of E-cig vapor on the functional human ciliated airway epithelium. The airway epithelium expresses several isoforms of nicotinic acetylcholine receptors (nAChRs), transient receptor potential (TRP) cation channel member A1 (TRPA1), and other TRP channels, which are all calcium (Ca2+)-permeant. Nicotine is reported to stimulate both nAChRs and TRPA1, and some E-cig flavors are TRP agonists, such as cinnamaldehyde (TRPA1), vanillin (TRPV1), and menthol (TRPM8). The basic hypothesis of this proposal is that E-cig vapor components nicotine and cinnamaldehyde compromise mucociliary function by stimulating nAChRs and TRPA1 to cause sustained Ca2+ influx. Research goals for this study are to identify a molecular mechanism(s) for how E-cig vapor impairs mucociliary function and to develop novel high-throughput methodology for establishing continuous mucociliary transport in vitro. The latter will be used to probe adverse/therapeutic effects of aerosolized compounds. These goals will be tested in primary human bronchial epithelial cells differentiated at the air-liquid interface, using physiologically-relevant exposures, and measuring in vitro parameters of mucociliary function such as mucociliary transport, ciliary beating, and airway surface hydration. Training goals for this proposal are to develop expertise in studying pulmonary effects of inhaled toxicants and to become immersed in translational research by working in a diverse team composed of clinicians and scientists. Completion of this study will fulfill the unmet need for clarification and information regarding effects of inhaled nicotine and E-cig flavorings. Use of relevant exposures and primary cultures will provide a compelling biological rationale to adapt public health policy. It will also inform clinicians on the `pro & cons' of E-cigs as smoking cessation tools as well as the impact on young never-smoking subjects who take up “vaping”. Lastly, completion of this training plan will generate data and expertise necessary for career transition from postdoctoral trainee to independent investigator.