Marshall K, Liu Z, Olfert IM, Gao W. Chronic electronic cigarette use elicits molecular changes related to pulmonary pathogenesis.
Toxicol Appl Pharmacol 2020;
406:115224. [PMID:
32890605 DOI:
10.1016/j.taap.2020.115224]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 08/26/2020] [Accepted: 08/31/2020] [Indexed: 12/23/2022]
Abstract
The relative safety of chronic exposure to electronic cigarette (e-cig) aerosol remains unclear in terms of lung pathogenesis. Therefore, this study aims to evaluate gene/protein biomarkers, which are associated with cigarette-induced pulmonary injury in animals chronically exposed to nicotine containing e-cig aerosol. C57BL/6 J mice were randomly assigned to three exposure groups: e-cig, tobacco cigarette smoke, and filtered air. Lung tissues and/or paraffin embedded slides were used to evaluate gene and/or protein expressions of the CYP450 metabolism (CYP1A1, CYP2A5, and CYP3A11), oxidative stress (Nrf2, SOD1), epithelial-mesenchymal transition (E-cadherin and vimentin), lung pathogenesis (AhR), and survival/apoptotic pathways (p-AKT, BCL-XL, p53, p21, and CRM1). Expressions of E-cadherin and CRM1 were significantly decreased, while CYP1A1, AhR, SOD1 and BCL-XL were significantly upregulated in the e-cig group compared to the control (p < 0.05). Nuclear sub-cellular localization of p53, evaluated by immunohistochemistry staining, in bronchiolar tissues was higher in the e-cig group (25.3 ± 2.7%) as compared to controls (12.1 ± 1.8%) (p < 0.01). Although the biomarkers responses were not identical, in general, the responses had similar qualitative trends between the e-cig and cigarette groups. As these related molecular changes are involved in the pathogenesis of cigarette-induced lung injury, the possibility exists that e-cigs can produce a similar outcome. Although further investigation is warranted, e-cigs are unlikely to be considered as safe in terms of pulmonary health.
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