Electronic cigarette vaping triggers lipid mediated vocal fold mucosal injury

Electronic cigarettes (e-cigs) are nicotine delivery systems that have been touted as safer alternatives to smoking. A recently reported case of epiglottitis revealed a connection between vaping and swollen laryngeal and vocal fold (VF) structures that can lead to acute life-threatening airway obstruction. The clinical course and biopsy revealed direct epithelial injury and subsequent inflammatory reaction. Here we show that we were able to recapitulate this phenomenon in in vitro conditions. Exposure of engineered VF mucosae to 5% e-cig vapor extract for one week induced cellular damage in VF luminal epithelial cells, disrupting mucosal homeostasis and mucosal innate immune responses. Epithelial erosion was likely caused by the accumulation of solvents and lipid particles, most likely medium chain fatty acids, in the cytosol and intercellular spaces, which altered lipid metabolism and plasma membrane properties. In summary, vaping represents a threat to the VF mucosa health and airway protection.