Hypomethylation of LINE-1 repeat elements and global loss of DNA hydroxymethylation in vapers and smokers

Abstract

The outbreak of vaping-related severe lung injuries and deaths and the epidemic of teen vaping in the U.S. underscore the urgent need for determining the biological consequences of electronic cigarette (e-cig) use. We have investigated the association between vaping and epigenetic changes by quantifying DNA methylation levels in Long Interspersed Nucleotide Element 1 (LINE-1) and global DNA hydroxymethylation (5-hmC) levels and measuring the expression level of enzymes catalysing the respective processes in peripheral blood of exclusive vapers, smokers, and controls, matched for age, gender, and race (n = 45). Both vapers and smokers showed significant loss of methylation in LINE-1 repeat elements in comparison to controls (P = 0.00854 and P = 0.03078, respectively). Similarly, vapers and smokers had significant reductions in 5-hmC levels relative to controls (P = 0.04884 and P = 0.0035, respectively). Neither the LINE-1 methylation levels nor the global 5-hmC levels were different between vapers and smokers. There was a direct correlation between methylation levels in the LINE-1 elements and global 5-hmC levels in the study subjects (r = 0.31696, P = 0.03389). 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. Our findings support follow-up genome-wide investigations into the epigenetic effects of vaping, which may further clarify the health consequences of ecig use.

Tobacco, but Not Nicotine and Flavor-Less Electronic Cigarettes, Induces ACE2 and Immune Dysregulation

“…Therefore, despite the lack of a correlation between vaping and ACE2 activity, it is possible that vaping may affect COVID-19 infections via an ACE2-independent mechanism. Indeed, vaping has been correlated to a loss of methylation and immune activation [ 66 ]. We investigated whether the ACE2-independent mechanism is cytokine dysregulation.…”

E-Cigarette Use and Adult Cigarette Smoking Cessation: A Meta-Analysis

“…77 Halpern et al 16 Hajek et al 73 Lee et al 76 Lucchiari et al 18 Walker et al 19 Hatsukami et al 74 Holliday et al 75 Bullen et al 17 Lee et al 77 Halpern et al 16 Hajek et al 73 Lee et al 76 Lucchiari et al 18 Walker et al 19 Hatsukami et al 74 Holliday et al 75 Bullen et al 17 1 extent that people who smoke simply add e-cigarettes to their cigarette smoking (becoming so-called dual users), their risk of heart disease, [80][81][82][83] lung disease, 84,85 and cancer 86 disease, [80][81][82][83]92 lung disease, 84,85,93,94 and cancer. 86,95,96 By contrast, the RCTs suggest that however, also requires that they be "safe," meaning that the benefit-to-risk ratio must be favorable. As noted previously, recent evidence links e-cigarette use to heart disease, [80][81][82][83]92 lung disease, 84,85,93,…”

“…86,95,96 By contrast, the RCTs suggest that however, also requires that they be "safe," meaning that the benefit-to-risk ratio must be favorable. As noted previously, recent evidence links e-cigarette use to heart disease, [80][81][82][83]92 lung disease, 84,85,93,94 and cancer 86,95,96 ; this evidence raises questions about whether the benefit-to-risk ratio would be favorable enough for approval as a medication. The fact that 80% of people who smoked in the e-cigarette arm of 1 of the RCTs were still using e-cigarettes a year later compared with 9% of nicotine replacement therapy users reinforces this concern.…”

Exogenous coronavirus interacts with endogenous retrotransposon in human cells

“…What's more, increased expression of retrotransposon LINE-1 contributes to age-associated in ammation in several tissues (40). Additionally, vapers and smokers demonstrated higher retrotransposon expression and hypomethylation at associated loci (41). Also, people with neurological disorders may have higher retrotransposon expression and retrotransposition activity (42).…”