Scientists have discovered that the new coronavirus spike protein is capable of inhibiting pain, which may explain why so many Covid-19 patients are asymptomatic
Sars-CoV-2 is capable of relieving pain, according to a study published on Thursday (1) in the journal Pain by scientists at the University of Arizona, in the United States. The finding may explain why almost half of patients with the new coronavirus have few or no symptoms, although they are able to spread the disease.
"It makes a lot of sense that the reason for the relentless spread of Covid-19 may be that, in the early stages, you feel good, as if nothing is wrong, because your pain has been suppressed," says Rajesh Khanna, one of the researchers, in declaration. "You have the virus, but you don't feel bad because your pain is gone. If we can prove that this relief is what is causing Covid-19 to spread further, it will be of enormous value."
Viruses infect host cells through protein receptors on cell membranes. At the beginning of the pandemic, scientists established that the spike protein in Sars-CoV-2 uses the angiotensin-converting enzyme 2 (ACE2) receptor to enter the body. Shortly afterwards, new studies indicated that neuropilin-1 is also a receptor for the new coronavirus.
"This caught our attention because, for the past 15 years, my laboratory has been studying a complex of proteins and pathways related to the processing of pain linked to neuropilin," says Khanna. "So, we realized that this could mean that maybe the spike protein is involved in some kind of pain processing."
Many biological pathways signal the feeling of pain in the body. One of them is the VEGF-A protein, which plays an essential role in the growth of blood vessels. In addition, it has been linked to diseases such as cancer, rheumatoid arthritis and, more recently, Covid-19.