Electronic cigarettes cause alteration in cardiac structure and function in diet-induced obese mice.

Abstract

In spite of the widespread use of electronic cigarettes, also known as e-cigarettes, and the proposed adverse cardiac effects of nicotine, the detrimental effects of e-cigarettes on the heart are not well known. This study examines the detrimental effects of e-cigarettes with nicotine at doses that yield circulating nicotine and cotinine in the ranges similar to the levels found in habitual smokers, and a high fat diet (HFD) on cardiac structure and function in a commonly used model of diet-induced obesity (DIO). C57BL/6J mice on an HFD were exposed to e-cigarette in the presence (2.4% nicotine) or absence (0% nicotine) of nicotine and saline aerosol for 12 weeks. Echocardiographic data demonstrated a decrease in left ventricular (LV) fractional shortening, LV ejection fraction, and velocity of circumferential fiber shortening (VCF) in mice treated with e-cigarette (2.4% nicotine) compared to e-cigarette (0% nicotine) or saline exposed mice. Cardiomyocytes (CMs) of mice treated with e-cigarette (2.4% nicotine) exhibited LV abnormalities, including lipid accumulation (ventricular steatosis), myofibrillar derangement and destruction, and mitochondrial hypertrophy, as revealed by transmission electron microscopy. The detrimental effects of e-cigarettes (2.4% nicotine) on cardiac structure and function was accompanied by increased oxidative stress, plasma free fatty acid levels, CM apoptosis, and inactivation of AMP-activated protein kinase and activation of its downstream target, acetyl-CoA-carboxylase. Our results indicate profound adverse effects of e-cigarettes (2.4% nicotine) on the heart in obese mice and raise questions about the safety of the nicotine e-cigarettes use.

• Authors: Kamrul M Hasan, Theodore C Friedman, Meher Parveen, Jorge Espinoza-Derout, Francisco Bautista, Mohammad M Razipour, Xuesi M Shao, Maria C Jordan, Kenneth P Roos, Sushil K Mahata, Amiya P Sinha-Hikim
• Journal: PloS one (PLoS One) Vol. 15 Issue 10 Pg. e0239671 ( 2020) ISSN: 1932-6203 [Electronic] United States
• PMID: 33002059 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Fatty Acids, Nonesterified
• Nicotine
• Cotinine

Topics

• Animals
• Cotinine (blood)
• Diet, High-Fat (adverse effects)
• Echocardiography
• Electronic Nicotine Delivery Systems
• Fatty Acids, Nonesterified (blood)
• Heart (drug effects, physiopathology)
• Heart Ventricles (drug effects, pathology)
• Male
• Mice
• Mice, Inbred C57BL
• Mice, Obese
• Microscopy, Electron, Transmission
• Myocardium (pathology, ultrastructure)
• Nicotine (adverse effects, blood)
• Oxidative Stress (drug effects)
• Smoking (adverse effects)
• Ventricular Dysfunction, Left (chemically induced)