Nicotine promotes e-cigarette vapour-induced lung inflammation and structural alterations.

Abstract

BACKGROUND:

Electronic cigarette (e-cigarette) vapour is gaining popularity as an alternative to tobacco smoking and can induce acute lung injury. However, the specific role of nicotine in e-cigarette vapour and its long-term effects on the airways, lung parenchyma and vasculature remain unclear.

RESULTS:

In vitro exposure to nicotine-containing e-cigarette vapour extract (ECVE) or to nicotine-free e-cigarette vapour extract (NF ECVE) induced changes in gene expression of epithelial cells and pulmonary arterial smooth muscle cells (PASMCs), but ECVE in particular caused functional alterations (e.g. a decrease in human and mouse PASMC proliferation by 29.3±5.3% and 44.3±8.4%, respectively). Additionally, acute inhalation of nicotine-containing e-cigarette vapour (ECV) but not nicotine-free e-cigarette vapour (NF ECV) increased pulmonary endothelial permeability in isolated lungs. Long-term in vivo exposure of mice to ECV for 8 months significantly increased the number of inflammatory cells, in particular lymphocytes, compared to control and NF ECV in the bronchoalveolar fluid (BALF) (ECV: 853.4±150.8 cells·mL-1; control: 37.0±21.1 cells·mL-1; NF ECV: 198.6±94.9 cells·mL-1) and in lung tissue (ECV: 25.7±3.3 cells·mm-3; control: 4.8±1.1 cells·mm-3; NF ECV: 14.1±2.2 cells·mm-3). BALF cytokines were predominantly increased by ECV. Moreover, ECV caused significant changes in lung structure and function (e.g. increase in airspace by 17.5±1.4% compared to control), similar to mild tobacco smoke-induced alterations, which also could be detected in the NF ECV group, albeit to a lesser degree. In contrast, the pulmonary vasculature was not significantly affected by ECV or NF ECV.

CONCLUSIONS:

NF ECV components induce cell type-specific effects and mild pulmonary alterations, while inclusion of nicotine induces significant endothelial damage, inflammation and parenchymal alterations.

• Authors: Elsa T Roxlau, Oleg Pak, Stefan Hadzic, Claudia F Garcia-Castro, Marija Gredic, Cheng-Yu Wu, Julia Schäffer, Balachandar Selvakumar, Alexandra Pichl, David Spiegelberg, Janik Deutscher, Mariola Bednorz, Katharina Schäfer, Simone Kraut, Djuro Kosanovic, Esraa M Zeidan, Baktybek Kojonazarov, Susanne Herold, Ievgen Strielkov, Andreas Guenther, Jochen Wilhelm, Mohamed M A Khalifa, Ashraf Taye, Ralf P Brandes, Matthias Hecker, Friedrich Grimminger, Hossein A Ghofrani, Ralph T Schermuly, Werner Seeger, Natascha Sommer, Norbert Weissmann
• Journal: The European respiratory journal (Eur Respir J) Vol. 61 Issue 6 (06 2023) ISSN: 1399-3003 [Electronic] England
• PMID: 37105573 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright ©The authors 2023.

Chemical References

• Nicotine
• E-Cigarette Vapor
• Plant Extracts

Topics

• Humans
• Animals
• Mice
• Nicotine (adverse effects)
• Electronic Nicotine Delivery Systems
• E-Cigarette Vapor (adverse effects, metabolism)
• Pneumonia (etiology, metabolism)
• Lung (metabolism)
• Plant Extracts (metabolism, pharmacology)