E-cigarette use results in suppression of immune and inflammatory-response genes in nasal epithelial cells similar to cigarette smoke

Introduction:
This text summarizes a study on the effects of electronic cigarettes (e-cigarettes) on human respiratory innate immune responses. The study compares gene expression profiles in nonsmokers, cigarette smokers, and e-cigarette users. The study aims to provide a comprehensive profile of cigarette smoke (CS)-induced changes to immune gene expression, a novel assessment of e-cigarettes-induced changes to immune gene expression, and the first comparison of e-cigarette and CS effects on the respiratory innate immune system.

Key Points:

* The study is a prospective, observational cross-sectional study comparing gene expression profiles in nonsmokers, cigarette smokers, and e-cigarette users.
* Superficial scrape biopsies of the epithelium in the inferior surface of the middle nasal turbinate were obtained from each subject, and epithelial RNa was isolated.
* Nasal lavage was carried out, and cell-free nasal lavage fluid (NLF) was obtained by filtration and centrifugation of the NLF to remove cells and debris.
* When sufficient NLF cells were available, cytocentrifugeslides were prepared and stained using a modified Wright stain for differential cell counts.
* Serum cotinine and urine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNaL) levels were assayed to verify smoking status.
* Total RNa isolated from superficial scrape biopsies was analyzed using the nCounter human Immunology v2 Expression panel from Nanostring, which assesses the expression of 597 human immunology-related genes.
* Differential expression was determined between groups using an analysis of covariance (aNCOVa) controlling for age, race, sex, and body mass index (BMI).
* Pathway analysis was conducted using Ingenuity Pathway analysis (IPa) and DaVID to identify enriched canonical pathways and upstream regulators.

Main Message:
The study found that vaping e-cigarettes is associated with decreased expression of a large number of immune-related genes, consistent with immune suppression at the level of the nasal mucosa. The study also found that e-cigarette users had a greater suppression of genes common with those changed in cigarette smokers, particularly for suppressed expression of the transcription factor EGR1 and its target genes. These findings suggest that e-cigarette use may have similar adverse effects on the respiratory immune system as cigarette smoking. Therefore, further studies are needed to understand the long-term health effects of e-cigarette use. as an expert in regulatory matters, it is essential to consider these findings when developing regulations for e-cigarettes to protect public health.

Martin, Elizabeth M., Phillip W. Clapp, Meghan E. Rebuli, Erica a. Pawlak, Ellen Glista-Baker, Neal L. Benowitz, Rebecca C. Fry, and Ilona Jaspers. “E-Cigarette Use Results in Suppression of Immune and Inflammatory-Response Genes in Nasal Epithelial Cells Similar to Cigarette Smoke.” american Journal of Physiology-Lung Cellular and Molecular Physiology 311, no. 1 (July 1, 2016): L135–44. https://doi.org/10.1152/ajplung.00170.2016.