hypomethylation of LINE-1 repeat elements and global loss of DNa hydroxymethylation in vapers and smokers.

Introduction:
This paper presents a study on the association between vaping and epigenetic changes, specifically focusing on DNa methylation levels in Long Interspersed Nucleotide Element 1 (LINE-1) repeats and global DNa hydroxymethylation (5-hmC) levels. The study also measured the expression level of enzymes catalyzing these processes in peripheral blood of exclusive vapers, smokers, and controls. The findings have important implications for understanding the potential health consequences of e-cigarette use.

Key Points:

* The study included 45 subjects divided equally into three groups: exclusive vapers, cigarette smokers only, and control non-smokers non-vapers.
* Both vapers and smokers showed significant loss of methylation in LINE-1 repeat elements and significant reductions in 5-hmC levels relative to controls.
* There was a direct correlation between methylation levels in the LINE-1 elements and global 5-hmC levels in the study subjects.
* Inverse and statistically significant correlations were found between both the LINE-1 methylation levels and the global 5-hmC levels and various vaping/smoking metrics in the study subjects.
* There were modest but not statistically significant changes in transcription of DNa methyltransferases and ten-eleven translocation enzymes in both vapers and smokers relative to controls.
* Plasma cotinine levels, exhaled CO levels, and COhb levels were used to verify the vaping/smoking status of the study population.
* The study provides evidence for epigenetic changes in vapers, similar to those observed in smokers, which may contribute to the health consequences of e-cigarette use.

Main Message:
This study highlights the importance of investigating the epigenetic effects of vaping in clarifying the health risks or potential benefits of e-cigarette use compared to smoking. The findings suggest that vaping may lead to epigenetic changes that are similar to those observed in smoking, which could have implications for the long-term health effects of e-cigarette use. Further research is needed to provide a more comprehensive understanding of the epigenetic modifications associated with vaping, which can inform future regulations and public health policies.

Caliri aW, Caceres a, Tommasi S, Besaratinia a. hypomethylation of LINE-1 repeat elements and global loss of DNa hydroxymethylation in vapers and smokers. Epigenetics. 2020;15(8):816-829. doi:10.1080/15592294.2020.1724401