Vaping: Cell Damage at the Receiving ENDS.

Introduction:
This editorial discusses a study examining the effects of electronic nicotine delivery systems (ENDS), also known as vaping devices or e-cigarettes, on the viability of cells in the respiratory tract. The study used an in vitro system to deliver ENDS aerosol to human and murine respiratory epithelial cells and found substantial cell death. The study also investigated the transepithelial resistance of a human respiratory epithelial cell monolayer and the impact of ENDS aerosol on macrophages, finding pronounced effects on epithelial barrier function and an inflammatory death pathway in macrophages.

Key Points:

* The study found that exposure to ENDS aerosol led to substantial cell death in respiratory epithelial cells.
* The addition of nicotine aggravated cell death rates, whereas nicotine alone had no effect on epithelial cell viability.
* The study found a pronounced decrease in transepithelial resistance of a human respiratory epithelial cell monolayer after daily ENDS aerosol exposure over 1 week, suggesting dramatic effects on the epithelial barrier function.
* The study found that macrophages responded to ENDS aerosol by undergoing pyroptosis, an inflammatory death pathway resulting in cell leakage and release of intracellular contents, further aggravating local inflammation.
* The study noted a decreased capacity of macrophages to perform phagocytosis, which was aggravated by the addition of nicotine.
* The study found that efferocytosis, the clearance of apoptotic cells by macrophages, was impaired in the presence of nicotine.
* The study highlights the potential danger of vaping and calls for large-scale studies to investigate the potentially harmful effects in humans.

Main Message:
The study provides important information about the cellular cytotoxicity of ENDS aerosol in vitro, addressing important aspects of the ongoing confusion about the potentially harmful effects of e-cigarettes. The current lack of consistent data, combined with the large variety of ENDS compositions, makes it difficult to fully understand the biological impact. More data from in vivo experiments are urgently needed, which are currently limited. The study's findings highlight the potential danger of vaping and truly call for large-scale studies to investigate the potentially harmful effects in humans. It is important to note that the use of e-cigarettes is not without risk and more research is needed to fully understand the potential harms associated with their use.

Knapp S. Vaping: Cell Damage at the Receiving ENDS. american journal of respiratory cell and molecular biology. 2020;63(3):271-272. doi:10.1165/rcmb.2020-0244ED