Host’s DNA methylation alterations accompanying COVID-19 infection: a review article

Abstract

The latest global pandemic of severe acute respiratory syndrome (SARS-CoV-2) is triggered by a highly pathogenic RNA virus initiating coronavirus disease 2019 . Epigenetic modifications (mainly DNA methylation and histone modification) are key regulators of the transcriptome. Such epigenetic marks have the ability to switch on/off gene expression. Additionally, the epigenetic marks are known to be dynamic, reversible, and more vulnerable, than the genome, in response to environmental insults including pathogenic invaders such as viruses and bacteria. During the period of COVID-19 pandemic, much more efforts have been concentrated on characterizing the SARS-CoV-2 virus, determining how it enters the cells, and revealing the associated health complications. Interestingly, the SARS-CoV-2 RNA virus is believed to have the potential of hijacking the host immune cells' epigenome to avoid antiviral defense. However, a very little scientific understanding of how the host epigenome responds to COVID-19 infection. This review summarizes the existing knowledge and provides an overview of a considerable amount of literature published on this topic, especially the contribution of DNA methylation alterations in triggering the cytokine storm in pulmonary tissues mainly by the hyper-activation of the immune system and uncontrolled influx of cytokines in response to COVID-19 infection.