Exposure to Electronic Cigarette Vapor Causes Systemic Accumulation of Biomolecular Free Radicals

Abstract

Little is known regarding the impact of electronic cigarette (e‐cig) usage in the human body. However, emerging literature suggests that vaping results in endothelial cell mediated vascular impairments, altered thrombosis, and depressed immune function (similar to that observed with smoking). Since e‐cigs are marketed as a ‘safer’ alternative to traditional cigarettes, it is important to characterize mechanisms through which e‐cigs may induce cellular insult. It is known that traditional cigarette use results in systemic accumulation of biomolecular free radicals (BFR), thus we sought to determine whether exposure to e‐cig vapor will result in significant systemic increases in BFR. We hypothesize that vaping will increase the relative amount of BFR accumulation in vital tissues in a time‐dependent manner.To identify BFR in‐vivo, C57BL/7 mice were given IP 1.5 g/kg DMPO (5,5‐dimethyl‐l‐pyrroline‐l‐oxide) spin‐trap in 2 doses over 1 hour, and acutely exposed to french vanilla‐flavored e‐cig vapor (18 mg nicotine) for either 1 hour (n=3) or 4 hours (n=3). Sham mice were exposed to ambient air (n=3). Immediately following exposure, the mice were anesthetized, perfused with PBS via intra‐ventricular catheterization, organs/tissues were harvested and fixed in paraformaldehyde/sucrose, flash‐frozen in liquid nitrogen and then fixed in TFM. Imaging from fluorescent immunohistochemical labeling revealed significant increase BFR accumulation in the liver (223%, p<0.05) and to lesser extent in the heart (133%, p<0.05) in 1‐hour exposed animals. Similar trends for increased BFR (albeit not statistically significant) were found in the lung (236%) and brain (124%) in 4‐hour exposed group compared to air exposed controls.In summary, we found significant increase in the presence of BFR in the liver and heart of mice acutely exposed to 1‐hour of e‐cig vapor compared to controls, with similar trends in other tissue beds (lung, brain) after 4‐hours vape exposure. This is a pilot study which needs additional samples for further evaluation, but suggests that vaping induces BFR accumulation in multiple organs which could lead to cellular damage and tissue dysfunction.Support or Funding InformationSupport: WVU Cancer Institute Philip R Dino Innovative Research Grant (IMO); Transition Grant Support; Office of Research and Graduate Education (IMO), WVU Health Sciences Center APS STRIDE Fellowship (JO); NIHGMS 5U54GM104942‐03 (PDC)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.