New research has shown that e-cigarette vapor exposure leads to higher levels in the coronavirus receptor ACE-2, in mice's lungs. Nicotine may increase that increase in male mice.PHILADELPHIA – Vaping or e-cigarettes can cause serious lung damage. There have been concerns over the impact of vaping on symptoms and infection, especially after the COVID-19 virus was discovered. There is evidence that vapers are at higher risk for COVID-19. Research shows that there is a higher COVID-19 death rate among men than in women. Furthermore, vapers are more likely to smoke than women. These observations are not linked, however.Jefferson's new research sheds light on the matter. It shows that vapor from e-cigarettes can increase coronavirus receptor levels in male mice's lungs, especially when nicotine is present. This could make the virus easier to infect. These findings were published in Journal of Investigative Medical on April 29.The novel coronavirus binds to angiotensin-converting-enzyme 2 (ACE-2) receptor in our linings of our airways and opens its pathway into our lung cells by using the spike-like protein at its surface.Pawan Sharma, PhD, co-senior author and co-author of the study, said that cigarette smokers have higher levels ACE-2 in their lungs. This is a well-known risk factor for developing lung disease or infection. We wanted to determine if vaping or e-cigarettes have a similar effect and if there are any differences between males and females.Researchers placed male and female mice in boxes attached to an automated system that provided precisely controlled amounts of ecigarette vapor for 30 minutes, twice daily for 21 days. Comparing to mice that were exposed to room air, vaping caused inflammation and decreased lung function in mice. These effects occurred regardless of whether nicotine was added to vapor. This highlights the inherent dangers of vaping.The ACE-2 receptor was also found to be higher in vapor-exposed male and female mice. Although this was not confirmed in the current study however, it is possible that the virus could enter the lungs more easily if there are higher levels of ACE-2 receptor. This would increase susceptibility to infection.Interestingly, male mice showed a higher level of ACE-2 when there was nicotine in the vapor.Researchers are the first to show that nicotine and vaping can have a significant effect on ACE-2 levels in vivo. Although more research is required to fully understand the complex risk factors for COVID-19 and their implications, this finding sheds light on physiological differences that could make one sex more vulnerable.Dr. Sharma says that "our findings provide justification for investigating the effect of vaping ACE-2 levels within the lungs of human beings." "If ACE-2 levels are similar to those seen in vaping, this provides additional evidence that vaping is a risk factor in COVID-19. This can help us understand how we can prevent and mitigate infection in this group."###Dr. Amir A. Zeki, one of the authors, is also an associate editor of Journal of Investigative Medicine. InVixa, Inc., a private startup, is co-founded by Dr. Zeki. It develops inhaled treatments for COVID-19 prevention and treatment. Other conflicts of interest are not reported by the authors.Article Reference: Pawan Sharma, Amir A. Zeki and Vegi Naidu, "Sex differences after e-cigarette vapor induction of angiotensin converting protein 2 (ACE-2 in mouse lungs and its relevance for COVID-19", DOI 10.1136/jim-20-001768, Journal of Investigative medicine, 2021Media Contact: Karuna MDA, 267-624-792, karuna.meda@jefferson.edu
