E-Cigarette Aerosol Exposure Induces Reactive Oxygen Species, DNA Damage, and Cell Death in Vascular Endothelial Cells

Toxicol Sci. 2016 Dec;154(2):332-340. doi: 10.1093/toxsci/kfw166. Epub 2016 Sep 9.

Abstract

Cigarette smoking remains one of the leading causes of preventable death worldwide. Vascular cell death and dysfunction is a central or exacerbating component in the majority of cigarette smoking related pathologies. The recent development of the electronic nicotine delivery systems known as e-cigarettes provides an alternative to conventional cigarette smoking; however, the potential vascular health risks of e-cigarette use remain unclear. This study evaluates the effects of e-cigarette aerosol extract (EAE) and conventional cigarette smoke extract (CSE) on human umbilical vein endothelial cells (HUVECs). A laboratory apparatus was designed to produce extracts from e-cigarettes and conventional cigarettes according to established protocols for cigarette smoking. EAE or conventional CSE was applied to human vascular endothelial cells for 4-72 h, dependent on the assay. Treated cells were assayed for reactive oxygen species, DNA damage, cell viability, and markers of programmed cell death pathways. Additionally, the anti-oxidants α-tocopherol and n-acetyl-l-cysteine were used to attempt to rescue e-cigarette induced cell death. Our results indicate that e-cigarette aerosol is capable of inducing reactive oxygen species, causing DNA damage, and significantly reducing cell viability in a concentration dependent fashion. Immunofluorescent and flow cytometry analysis indicate that both the apoptosis and programmed necrosis pathways are triggered by e-cigarette aerosol treatment. Additionally, anti-oxidant treatment provides a partial rescue of the induced cell death, indicating that reactive oxygen species play a causal role in e-cigarette induced cytotoxicity.

Keywords: anti-oxidants; cardiovascular system; cytotoxicity; e-cigarettes; endothelial cells; oxidative stress..

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aerosols
  • Antioxidants / pharmacology
  • Apoptosis / drug effects*
  • Cells, Cultured
  • DNA Damage*
  • Dose-Response Relationship, Drug
  • Electronic Nicotine Delivery Systems*
  • Human Umbilical Vein Endothelial Cells / drug effects*
  • Human Umbilical Vein Endothelial Cells / metabolism
  • Human Umbilical Vein Endothelial Cells / pathology
  • Humans
  • Inhalation Exposure
  • Necrosis
  • Nicotine / toxicity*
  • Nicotinic Agonists / toxicity*
  • Oxidative Stress / drug effects*
  • Reactive Oxygen Species / metabolism*
  • Risk Assessment
  • Smoke / adverse effects*
  • Time Factors
  • Tobacco Products / toxicity*

Substances

  • Aerosols
  • Antioxidants
  • Nicotinic Agonists
  • Reactive Oxygen Species
  • Smoke
  • Nicotine