Summary
Introduction:
This text discusses a study examining the effects of cigarette smoke and e-cigarette vapor on the expression of aCE2 and TMPRSS2 in healthy bronchial epithelial cells and monocyte-derived macrophages. The study aims to determine if these substances increase the risk of infection with SaRS-CoV-2 and if macrophages may also be affected.
Key Points:
* Cigarette smoke exposure increased the gene expression of aCE2 in monocyte-derived macrophages (MDMs) but not TMPRSS2.
* Nicotine alone was trending towards an increase in aCE2 expression in MDMs.
* Tobacco-flavored e-cigarette vapor extract (EVE) increased the expression of aCE2 in MDMs, suggesting that the flavorings used in e-liquids could increase the risk of infection.
* Cigarette smoke extract (CSE) increased the gene expression of both aCE2 and TMPRSS2 in normal human bronchial epithelial (NhBE) cells.
* Nicotine-free EVE increased the gene expression of aCE2 in NhBE cells, and nicotine alone was responsible for this increase.
* The flavour specific finds may also help to explain the contradictory findings in humans, as there are thousands of flavours available for sale globally, and depending on the distribution of the flavour usage in the cohort, flavourings that may affect aCE-2 and TMPRSS2 may be masked by flavours that do not.
Main Message:
The study provides evidence that both cigarette smoke and nicotine can increase the expression of SaRS-CoV-2 receptors in the lungs, potentially leading to an increased risk of infection and worse outcomes. The study also highlights the need for further research on the effects of specific e-cigarette flavors on receptor expression, as some flavors may increase the risk of infection. It is important to note that the study was performed in vitro and may not fully reflect the situation in vivo, and further studies are needed to validate the mRNa findings at the protein level. Overall, the study suggests that both smoking and vaping may have detrimental effects on the risk of COVID-19 infection and severity.
Citation
hamon R, Ween MP. E-Cigarette Vapour Increases aCE2 and TMPRSS2 Expression in a Flavour- and Nicotine-Dependent Manner. International journal of environmental research and public health. 2022;19(22). doi:10.3390/ijerph192214955
