# The Effect of Cigarettes and E-Cigarettes on Epithelial-Derived Extracellular Vesicles: A Systematic Review

## TL;DR

This systematic review explores how cigarettes and e-cigarettes affect lung epithelial-derived extracellular vesicles, which may contribute to lung inflammation and disease.

## Contribution

The study systematically reviews the impact of cigarette smoke and e-cigarette aerosol on epithelial-derived extracellular vesicles, highlighting gaps in e-cigarette research.

## Key findings

- Cigarette smoke exposure alters the molecular content of lung epithelial-derived EVs.
- EVs from cigarette-exposed cells can transfer cargo to neighboring cells, promoting inflammation and disease.
- Limited evidence exists on how e-cigarette aerosol affects epithelial-derived EVs.

## Abstract

Extracellular vesicles (EVs) are lipid-enclosed particles secreted from a wide variety of cells, with the ability to transfer biologically active content from parent to recipient cells. Lung epithelial-derived EVs (LE-EVs) play an important role in the progression of pulmonary disease, but there is limited evidence regarding the impact of cigarette smoke (CS) and electronic cigarette aerosol (ECA) on epithelial-derived EVs. The aim of this systematic review was to evaluate the current published literature on the impact of cigarette smoke and electronic cigarette aerosol on LE-EVs. Original research studies and clinical data were included, but research involving microparticles or non-epithelial-derived EVs was excluded. A total of 29 articles were identified from three databases (EMBASE, Web of Science and PubMed), of which nine demonstrated that CS exposure leads to molecular changes in epithelial-derived EVs, whereas 21 reported that CS-induced LE-EVs can deliver their cargo to neighbouring cells. The results highlighted that LE-EVs secreted in response to cigarette or e-cigarette exposure presented altered EV cargo, associated with increased cellular damage, inflammation and disease development. The current literature suggests that conventional and electronic cigarettes can influence the secretion of EVs from lung epithelial cells, with these EVs potentially playing a role in the development of lung inflammation. Nonetheless, there is limited research studying the impact of ECA on LE-EVS. Further research examining the impact of electronic cigarettes on lung epithelial-derived EVs, using robust human in vitro models coupled with clinical studies, is required.