The COVID-19 pandemic has been an unprecedented global health crisis, and researchers have been continuously investigating its complexities.
Unlike many other diseases, COVID-19 has been found to be influenced by the environment at the genetic level, leading to epigenetic manifestations that have opened up new avenues for drug development.
Epigenetic changes, which involve modifications to the structure of DNA or associated proteins without altering the underlying genetic code, have been associated with a wide range of diseases, including cancer, imprinting disorders, obesity, and viral infections. Understanding the role of epigenetics in COVID-19 has become crucial in determining the severity and fatality rate of the illness.
For several decades, scientists have known that viruses, including coronaviruses, utilize epigenetic regulation during their life cycle within hosts. Environmental factors, particularly modifications at specific regions of DNA called CpG islands, can impact key viral processes such as entry into host cells and maintenance within the body.
The intricate molecular mechanisms that regulate coronavirus pathogenesis through epigenetics are heavily reliant on host-virus interactions. Even though there are differences between viruses with DNA and RNA as genetic material, they all exploit host epigenetic reprogramming as a crucial part of their immune evasion pathways.
Recent studies have delved into the epigenetic factors involved in COVID-19 infection and host-pathogen interactions. Epigenetic changes have been implicated in the pathophysiology of the disease and its viral infectivity, primarily through chromatin remodeling and genome stabilization. These changes can also account for the differential infectivity of viruses in a tissue-specific, host-specific, gender-biased, or sex-biased manner. Essentially, epigenetics has a two-way effect on viral infections like COVID-19. On one hand, epigenetic modifications in the host can modulate the immune response, influencing the defense against the pathogen. On the other hand, epigenetic alterations within the virus’s replication mechanism can affect infection and prevalence.
DNA methylation at the chromatin level, leading to histone modifications and chromatin modeling, is one of the predominant epigenetic modifications observed. Key players in this process include modifying proteins like various types of sirtuins and non-coding RNAs, such as sRNA, miRNA, or long non-coding RNAs.
Histone-modifying enzymes, which facilitate epigenetic processes, also play a significant role. Numerous enzymes are involved in the epigenetic modification of histones, and some of them have been well-studied, including histone acetyltransferases/deacetylases, histone methyltransferases, and histone kinases. Additionally, there are other enzymes that work indirectly, such as DNA methyltransferases and proteins involved in DNA methylation or demethylation processes.
It is worth noting that viruses of the Coronaviridae family can also alter the host epigenome, adding another layer of complexity to the interplay between host and virus. Some of the epigenetic changes induced by the virus can negatively impact the host’s immune response, aiding viral survival and spread. Exploring viral infections through the lens of epigenomics is a relatively new but promising approach, as the enzymes responsible for these epigenetic changes could potentially serve as targets for new antiviral medications.
The modifications of receptor genes, which mediate synthesis and facilitate viral entry, represent a particularly intriguing area of study in the domain of SARS-CoV-2 epigenetics.
Figure 1 illustrates some common epigenetic modifications along with some yet-to-be-elucidated molecular cascades, providing a visual representation of the complexity and potential of this research field.
Figure 1 – Overview of various epigenetic modifications and unresolved molecular cascades.
While much attention has been focused on understanding the virus itself, emerging studies have revealed intriguing connections between SARS-CoV-2 and epigenetic changes that may also influence our food choices.
Epigenetic changes have been linked to SARS-CoV-2 infection. Epigenetic changes are changes to the way genes are expressed without changing the DNA sequence. They can be caused by a variety of factors, including environmental exposure, diet, and stress.
One study found that patients with COVID-19 had higher levels of DNA methylation in genes involved in the immune response. This suggests that epigenetic changes may play a role in the severity of COVID-19 infection.
Another study found that patients with COVID-19 had changes in the expression of genes involved in taste and smell. This suggests that epigenetic changes may be responsible for the loss of taste and smell that is often experienced by people with COVID-19.
Epigenetic changes can also affect food choices. For example, one study found that people with a certain genetic variant were more likely to prefer sweet foods. This preference was linked to epigenetic changes in genes involved in taste and reward.
Epigenetic changes can be influenced by diet. For example, one study found that a diet high in fruits and vegetables was associated with lower levels of DNA methylation in genes involved in obesity. This suggests that diet may play a role in preventing epigenetic changes that lead to unhealthy food choices.
Impact of SARS-CoV-2 on Epigenetic Changes:
SARS-CoV-2 is an RNA virus that primarily targets the respiratory system. However, recent research has shown that it can also infiltrate other tissues and organs, including the gastrointestinal tract. When the virus invades host cells, it can trigger various immune responses and cause inflammation. This inflammation and immune response, in turn, can lead to epigenetic changes in the infected cells.
The inflammatory response triggered by SARS-CoV-2 infection has been linked to changes in the expression of certain genes associated with taste and smell receptors. As a result, individuals infected with the virus may experience alterations in their taste and smell perceptions, leading to changes in their food preferences.
Epigenetic Changes and Food Choices
Epigenetic modifications can significantly impact our food preferences by influencing how we perceive taste and aroma. Taste receptors on the tongue and olfactory receptors in the nose are crucial in determining our preferences for sweet, salty, bitter, and umami flavors. Changes in gene expression due to epigenetic modifications can alter the sensitivity of these receptors, causing some individuals to find certain foods more appealing, while others may develop aversions to them.
Moreover, epigenetic changes can affect the brain’s reward and pleasure centers, leading to differences in how individuals respond to various foods. Some people may feel a heightened sense of reward and satisfaction from consuming certain foods due to epigenetic modifications that influence dopamine release in the brain. On the other hand, others may experience reduced pleasure from the same foods, leading them to prefer different options.
Epigenetic changes triggered by SARS-CoV-2 infection or other environmental factors can have long-term implications for food choices and overall dietary patterns. If these modifications persist over time, they may create lasting changes in taste preferences, leading individuals to develop new eating habits.
Furthermore, epigenetic changes can be passed on from one generation to the next through a process known as epigenetic inheritance. This means that the dietary preferences influenced by epigenetic modifications due to SARS-CoV-2 infection could potentially be passed down to future generations, shaping the food choices of offspring.
More research is needed to understand the role of epigenetic changes in SARS-CoV-2 infection and food choices. However, the research that has been done so far suggests that epigenetic changes may be a factor in both of these conditions.
Here are some additional ways that epigenetic changes can affect food choices:
- Epigenetic changes can influence our appetite and satiety hormones. For example, people with a certain genetic variant may be more likely to produce ghrelin, a hormone that makes us feel hungry. This can lead to overeating.
- Epigenetic changes can affect our gut microbiota. The gut microbiota is a community of bacteria that live in our intestines. They play a role in digestion, metabolism, and immunity. Epigenetic changes can alter the composition of the gut microbiota, which can influence our food choices.
- Epigenetic changes can affect our stress response. When we are stressed, we may be more likely to reach for unhealthy foods. Epigenetic changes can make us more or less susceptible to the effects of stress on our food choices.
By understanding how epigenetic changes can affect food choices, we can develop interventions that help people make healthier choices. This could include dietary interventions, stress management techniques, and lifestyle changes.
reference link :https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9967649/