Adolescent alcohol exposure alters DNA and RNA modifications in peripheral blood by liquid chromatography-tandem mass spectrometry analysis

Alcohol consumption is a critical risk factor contributing to a verity of human diseases. The incidence of alcohol use disorder increases across adolescence in recent years. Accumulating line of evidence suggests that alcohol-induced changes of DNA cytosine methylation (5-methyl-2'-deoxycytidine, 5mC) in genomes play an important role in the development of diseases. However, systemic investigation of the effects of adolescent alcohol exposure on DNA and RNA modifications is still lacked. Especially, there hasn't been any report to study the effects of alcohol exposure on RNA modifications. Similar to DNA modifications, RNA modifications recently have been identified to function as new regulators in modulating numbers of biological processes. In the current study, we systematically investigated the effects of alcohol exposure on both DNA and RNA modifications in peripheral blood of adolescent rats by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) analysis. The developed LC-ESI-MS/MS method enabled the sensitive and accurate determination of 2 DNA modifications and 12 RNA modifications. As for the alcohol exposure experiments, the adolescent rats were intraperitoneally injected with ethanol with an interval of one day for a total 14 days. The quantification results by LC-ESI-MS/MS analysis showed that adolescent alcohol exposure could alter both DNA and RNA modifications in peripheral blood. Specifically, we observed an overall decreased trend of RNA modifications. The discovery of the significant alteration of the levels of DNA and RNA modifications under alcohol exposure indicates that alcohol consumption may increase the risk of the incidence and development of diseases through dysregulating DNA and RNA modifications. (C) 2021 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.