Chronic electronic cigarette exposure in mice induces features of COPD in a nicotine-dependent manner

Introduction:
This article investigates the effects of exposure to aerosolized nicotine-free and nicotine-containing e-cigarette fluid on mouse lungs and normal human airway epithelial cells. The study found that inhaled nicotine-containing e-cigarette fluids triggered effects associated with the pathogenesis and progression of COPD, including airspace enlargement, mucous cell hypertrophy, release of inflammatory mediators, and altered epithelial ciliary function.

Key Points:

* Mice exposed to nicotine-containing e-cigarette fluids showed increased airway hyper-reactivity, airspace enlargement, and mucin production.
* Exposure to nicotine-containing e-cigarette fluids increased caspase 3/7 activity, suggesting increased apoptosis of lung cells.
* E-cigarette fluids containing nicotine caused a significant increase in the expression of several cytokines and proteases associated with tissue remodeling.
* Lung homogenates from mice exposed to nicotine in e-cigarette fluids showed increased phosphorylation of PKC α and a trend increase in lung phosphorylation of ERK.
* Exposure to nicotine-containing e-cigarette vapors reduced ciliary beating and CFTR ion conductance in human bronchial epithelial cells.
* Nicotine directly alters ciliary function and cytokine production in NhBE cells.
* This study suggests that nicotine is the key component responsible for the pathogenic changes in the lung caused by e-cigarettes.

Main Message:
This study provides important insights into the potential harmful effects of e-cigarettes, particularly nicotine inhalation, on lung health. The findings highlight the need for further research and regulation of e-cigarettes, especially in light of their increasing popularity as a smoking cessation tool. It is crucial to consider the potential risks associated with e-cigarette use, particularly regarding lung health, when advising patients on their use.

Garcia-arcos, Itsaso, Patrick Geraghty, Nathalie Baumlin, Michael Campos, abdoulaye Jules Dabo, Bakr Jundi, Neville Cummins, et al. “Chronic Electronic Cigarette Exposure in Mice Induces Features of COPD in a Nicotine-Dependent Manner.” Thorax 71, no. 12 (December 2016): 1119–29. https://doi.org/10.1136/thoraxjnl-2015-208039.