Abstract 16718: Electronic Cigarette Aerosols Alter Cardiac Expression of Genes Key to Electrical and Structural Remodeling in Mice

• Published in: Circulation (New York, N.Y.) N.Y.), 2018-11, Vol.138 (Suppl_1 Suppl 1), p.A16718-A16718
• Main Authors: Carll, Alex P, Fulghum, Kyle, Conklin, Daniel J, Bhatnagar, Aruni, Srivastava, Sanjay
• Format: Article
• Language: English
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/circ.138.suppl_1.16718

BackgroundElectronic cigarette (e-cig) use has mounted. Some health authorities have even proclaimed e-cigs are profoundly safer than conventional cigarettes. However, e-cigs generate several potentially cardiotoxic constituents by heating their solvent vehicles propylene glycol (PG) and vegetable glycerin (VG) into aerosols to deliver nicotine and flavors.ObjectivesTo investigate the effects of chronic E-cig exposures, with or without nicotine, on cardiac gene expression compared to mainstream cigarette smoke (MCS).MethodsHealthy C57BL/6J male mice were exposed chronically (12 weeks, 3 hours/day) to e-cig aerosols from an equal-ratio mixture of PG and VG (PG:VG) with nicotine (36 mg/mL) or without nicotine, or to MCS, and compared to filtered air control group (Air). Hearts (n=8/group) were assayed by quantitative PCR for expression of genes associated with electrical and structural remodeling.ResultsPG:VG exposure increased gene expression for a gap junction protein (connexin 43, 1.8-fold), voltage-gated potassium and sodium channels (Kv4.3, 2.5-fold; Nav1.5, 1.6-fold), calcium sequestration protein (sarco/endoplasmic reticulum calcium ATP-ase, 1.4-fold), cytokines (TGFβ1, 1.8-fold; TNF-α, 3.8-fold), and collagen III (3.8-fold) relative to Air (all P < 0.05). Nicotine did not enhance PG:VG’s effects on gene expression relative to PG:VG-alone (all P > 0.05), and cigarette smoke did not significantly affect any of the transcripts assayed (all P > 0.05 vs. Air).ConclusionsE-cigs may induce cardiac electrical and structural remodeling via their primary vehicle ingredients and irrespective of nicotine or flavors. Such effects could precipitate fatal arrhythmia, stroke, and/or heart failure. Electronic nicotine delivery systems may pose cardiac risks distinct from conventional cigarettes.