HYDERABAD: A new study by the Centre for Cellular and Molecular Biology (CCMB) gives insights into why some people are likely to lose their sense of smell, have more severe symptoms, need follow-ups post recovery, when they are infected with Covid-19. The study involved analysing genes of nearly 36 Covid-19 patients who had varying levels of severity of infection, ranging from ICU care to ward-level care, during the first wave. Five negative Covid-19 samples were also analysed.
The study published in Biorx found that the SARS-CoV-2 tends to react with genes leading to ‘downregulation’ or ‘upregulation’ of some of them, which are responsible for various body functions, like neurological and cardiovascular. Downregulation is the process by which a cell decreases the quantity of a cellular component, such as RNA or protein, in response to an external stimulus. Upregulation, on the other hand, is an increase in these components. Both these processes disrupt the way certain body functions occur.
During the course of the study, upregulation was found in immune response genes, whereas downregulation was seen in genes responsible for neurotransmission, cardiac and muscular contraction.
Researchers, however, said that a majority of the genes were downregulated. “A majority of the genes being downregulated suggests a host shutdown and large-scale systemic effects spanning not just lung and respiratory complications, but also cardiac, endocrine, and neurological issues,” noted the study. This is probably why some people experienced suppression of their sensory receptors, including olfactory and taste receptors.
According to the researchers, such a gene-level of study can show the long-lasting impact Covid has on patients. In the case of myocardial issues, the genes which provide key cardiac proteins and calcium ions crucial for cardiac muscle contraction were also affected.