Electronic cigarette exposure triggers neutrophil inflammatory responses

Abstract

BackgroundThe use of electronic cigarettes (e-cigs) is increasing and there is widespread perception that e-cigs are safe. E-cigs contain harmful chemicals; more research is needed to evaluate the safety of e-cig use. Our aim was to investigate the effects of e-cigs on the inflammatory response of human neutrophils.MethodsNeutrophils were exposed to e-cig vapour extract (ECVE) and the expression of CD11b and CD66b was measured by flow cytometry and MMP-9 and CXCL8 by ELISA. We also measured the activity of neutrophil elastase (NE) and MMP-9, along with the activation of inflammatory signalling pathways. Finally we analysed the biochemical composition of ECVE by ultra-high performance liquid chromatography mass spectrometry.ResultsECVE caused an increase in the expression of CD11b and CD66b, and increased the release of MMP-9 and CXCL8. Furthermore, there was an increase in NE and MMP-9 activity and an increase in p38 MAPK activation. We also identified several harmful chemicals in ECVE, including known carcinogens.ConclusionsECVE causes a pro-inflammatory response from human neutrophils. This raises concerns over the safety of e-cig use.Electronic supplementary materialThe online version of this article (doi:10.1186/s12931-016-0368-x) contains supplementary material, which is available to authorized users.

Phagocytosis and Inflammation: Exploring the effects of the components of E-cigarette vapor on macrophages

“…IL‐8 was shown to increase in neutrophils exposed to E‐cigarettes (Higham et al. 2016). Decreased IL‐1 β and TNF‐ α was observed in PBMCs exposed to nicotine (Ouyang et al.…”

“…2016; Higham et al. 2016), with even more likely given the size cut‐off in these studies. While there is definitive evidence of the dangers of cigarette smoking, the long‐term health risks of E‐cigarettes are not known.…”

Overview of Electronic Nicotine Delivery Systems: A Systematic Review

“…In cellular studies, exposure to ENDS vapor increased anti-inflammatory processes, 275,278 placed oxidative stress on exposed cells, 269,279,294,301 and increased cell apoptosis and necrosis. 305 Particular ENDS flavors are more cytotoxic than others, but generally most studied ENDS liquids are much less cytotoxic than cigarette smoke extract.…”

Electronic cigarettes—A review of the physiological health effects

“…Other flavouring compounds, vanillin and the chocolate flavouring 2,5-dimethylpyrazine, caused alterations in cellular physiology and compromised the ability of airway epithelial cells to maintain homeostasis (Sherwood and Boitano 2016). In another study, Higham et al (2016) discovered other known carcinogens such as allylthiourea, 2,3-benzofuran and toxicants such as gamma-hexenoic acid, 2-methyl valeric acid, piperidine, propanal, and styrene in EC vapour extracts. Kotandeniya et al (2015) reported the carcinogen biomarkers N-Nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) in the urine of EC users, albeit in lower amounts than with CCs.…”

“…Carnevale et al (2016) found similar results in healthy subjects with increased oxidative stress while vaping. In one study mentioned in Table 1 ( Higham et al 2016), vapours from ECs caused a pro-inflammatory response from human neutrophils. In that study, the effects were similar or more pronounced with EC vapours than with CC smoke extracts.…”