While many researchers have woken up, smelled the coffee, and realized the importance of epigenetic alterations in response to SARS-CoV-2 infections, many patients recovering from COVID-19 have been left unable to enjoy the olfactory joy of their first cup of java as each new day dawns. Now, well-caffeinated researchers led by Maria Lerm at Linköping University (Sweden) have revealed that specific long-lasting alterations to DNA methylation patterns induced by SARS-CoV-2 infection associate with negative impacts on odor perception.
This exciting finding “emanated” from a recent study based on their previous research into the epigenetic consequences of mycobacterial infections. In summary, the authors explored the importance of epigenetic mechanisms to SARS-CoV-2 defense and recovery by comparing epigenome-wide DNA methylation profiles of peripheral blood mononuclear cells (PBMCs) from recovered COVID-19 patients (mild-to-moderate disease) and PBMCs stimulated in vitro with SARS-CoV-2 to healthy uninfected controls.
Let’s hear from Huoman and Colleagues on how SARS-CoV-2-induced alterations to DNA methylation can impact the enjoyment of your daily mug of joe:
- Differential DNA methylation patterns robustly distinguish recovered COVID-19 patients from uninfected control patients
- Comparable results from the in vitro SARS-CoV-2 infection PBMC model provide further evidence for the importance of SARS-CoV-2-induced epigenetic alterations
- Analysis of in vivo and in vitro differential CpG DNA methylation patterns highlights a SARS-CoV-2-induced “module” comprised of 66 genes with an elevated level of intra-network interaction
- The INS, HSPA4, SP1, ESR1, TP53, and FAS genes form the important central section of the module
- Pathway over-representation analysis of module genes revealed the critical involvement of the Wnt signaling, muscarinic acetylcholine receptor signaling, and the gonadotropin-releasing hormone receptor pathways
- While studies have linked the Wnt signaling pathway to COVID-19 pathogenesis, studies blocking the muscarinic acetylcholine receptor 1/deleting the muscarinic acetylcholine receptors 1 and 3 have reported a negative impact on olfactory perception in mice
These perhaps not too pungent findings describe an epigenetic profile related to how SARS-CoV-2 infection induces the loss of smell in recovered COVID-19 patients; however, this research may also help define our functional defense strategies following viral assaults and guide the development of novel diagnostic and preventive measures.
For more on how SARS-CoV-2-induced DNA methylation alterations associate with the enjoyment of your caffeinated morning beverage, see Epigenetics, May 2022.