Smoker extracellular vesicles influence status of human bronchial epithelial cells

Cigarette smoking is a habit that has spread all over the world and is a significant risk factor for many diseases including cardiovascular disease, chronic obstructive pulmonary disease (COPD), asthma and lung cancer. Evaluation and understanding of tobacco health effects are of major interest worldwide and answer to important societal concerns. Identification of new biomarkers of exposure to tobacco smoke potentially implicated in COPD or lung carcinogenesis would allow a better observation of tobacco exposed population, thanks to screening establishment at reversible stages of pathological processes. In this study, we questioned whether cigarette smoking alters miRNA profiles of Extracellular Vesicles (EVs) present in human Broncho Alveolar Lavages (BALs), which could affect surrounding normal bronchial epithelial cells status. To this aim, BALs were carried out on 10 Smokers and 10 Non-Smokers, and EVs were isolated from the supernatants and characterized. We then compared the amount of 10 microRNAs (miRNAs) present in Smokers versus Non-Smokers BAL EVs and performed statistical analysis to discuss the biological significance by the smoking status and to evaluate BAL EV miRNAs as potential biomarkers of tobacco exposure. Finally, we tested the effects of smokers versus non-smokers EVs on human bronchial epithelial cells (BEAS-2B) to compare their influence on the cells status. Our study shows for the first time in human samples that smoking can alter lung EV profile that can influence surrounding bronchial epithelial cells.