Department of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama, United States.
Department of Environmental Health Sciences, The University of Alabama at Birmingham, Birmingham, Alabama, United States.
Am J Physiol Lung Cell Mol Physiol. 2023 May 1;324(5):L557-L570. doi: 10.1152/ajplung.00453.2021. Epub 2023 Feb 28.
Electronic cigarettes (e-cigs) are often promoted as safe alternatives to smoking based on the faulty perception that inhaling nicotine is safe until other harmful chemicals in cigarette smoke are absent. Previously, others and we have reported that, similar to cigarette smoke, e-cig aerosols decrease CFTR-mediated ion transport across airway epithelium. However, it is unclear whether such defective epithelial ion transport by e-cig aerosols occurs in vivo and what the singular contribution of inhaled nicotine is to impairments in mucociliary clearance (MCC), the primary physiologic defense of the airways. Here, we tested the effects of nicotine aerosols from e-cigs in primary human bronchial epithelial (HBE) cells and two animal models, rats and ferrets, known for their increasing physiologic complexity and potential for clinical translation, followed by in vitro and in vivo electrophysiologic assays for CFTR activity and micro-optical coherence tomography (μOCT) image analyses for alterations in airway mucus physiology. Data presented in this report indicate nicotine in e-cig aerosols causes ) reduced CFTR and epithelial Na channel (ENaC)-mediated ion transport, ) delayed MCC, and ) diminished airway surface hydration, as determined by periciliary liquid depth analysis. Interestingly, the common e-cig vehicles vegetable glycerin and propylene glycol did not affect CFTR function or MCC in vivo despite their significant adverse effects in vitro. Overall, our studies contribute to an improved understanding of inhaled nicotine effects on lung health among e-cig users and inform pathologic mechanisms involved in altered host defense and increased risk for tobacco-associated lung diseases.
电子烟(e-cigs)通常被宣传为吸烟的安全替代品,基于吸入尼古丁是安全的错误观念,而忽略了香烟烟雾中其他有害化学物质的存在。之前,其他人包括我们已经报告称,与香烟烟雾类似,电子烟气溶胶会降低气道上皮细胞中 CFTR 介导的离子转运。然而,目前尚不清楚电子烟气溶胶是否会在体内引起这种上皮离子转运缺陷,以及吸入尼古丁对黏液清除功能(MCC)的损害有何单一贡献,MCC 是气道的主要生理防御机制。在这里,我们在原代人支气管上皮(HBE)细胞以及两种动物模型(大鼠和雪貂)中测试了来自电子烟的尼古丁气溶胶的作用,这些动物模型因其生理复杂性不断增加以及在临床转化方面的潜力而被选中,随后进行了 CFTR 活性的体外和体内电生理测定以及气道黏液生理的微光学相干断层扫描(μOCT)图像分析。本报告中的数据表明,电子烟气溶胶中的尼古丁会导致:1)CFTR 和上皮钠离子通道(ENaC)介导的离子转运减少;2)MCC 延迟;3)气道表面水合作用减弱,通过纤毛液体深度分析来确定。有趣的是,尽管普通电子烟的载体——蔬菜甘油和丙二醇在体外具有显著的不良影响,但它们在体内并不影响 CFTR 功能或 MCC。总的来说,我们的研究有助于更好地了解电子烟使用者吸入尼古丁对肺部健康的影响,并阐明改变宿主防御和增加与烟草相关的肺部疾病风险的相关病理机制。