Another day in the strange world of Covid
A new finding suggests Covid-19 doesn’t just bind to the ACE2 receptor, it also binds to a key pain receptor called neuropilin-1 receptor (NRP-1). This could explain why some people with a high viral load are asymptomatic and infectious but unaware they are unwell. It’s like the virus is arriving with it’s own morphine. In theory this might be a successful adaption from the virus’s point of view as it may increase the spread of the disease if infected people wander around able to shed virus for longer.
Despite being fed up with the WuFlu, the efficient perfidy is something to behold (at least to a microbiologist). It’s like a pocketknife.
On the down side, the virus may still be damaging tissues in this painless state, which might explain some of those findings of lung and heart damage even in mild or asymptomatic cases.
There is at least one potentially very nice payoff. The finding from the University of Arizona, may lead to the design of whole new painkillers based on the coronavirus spike that is “better than opioids”. The lead author says he has been contacted by people who had chronic pain, but noticed it disappeared while they were infected. The pain returned later as they recovered.
Perhaps we can dose people up on little parts of Covid spikes and stop a whole lot of pain and suffering in other diseases. We will get the better of this box of malware.
Neuropilins (both NRP1 and NRP2) are also associated with one of the pain pathways of the body.
According to the study published in Pain, the journal of the International Association for the Study of Pain, on 1 October 2020, the spike proteins of SARS-CoV-2 also bind to the neuropilin receptors exactly at the same spot as VEGF-A, thus interfering with the pain pathway.
To confirm their finding, scientists conducted a series of experiments on rodent models in the labs, where they used VEGF-A as a trigger to provoke the excitability of the nerve cells, thus creating pain. Following that the scientists injected the rodents with SARS-CoV-2 spike protein.
The scientists concluded that by designing small molecules against neuropilin receptors, they would be able to form a pain-relieving medication better than opioids.
Better than opioids?
He has received dozens of anecdotal emails since his study published from patients who had chronic pain conditions before getting sick. Then they got COVID and now their pain is gone,” he said. “I fully acknowledge that these are anecdotes … but it’s a recurrent theme. It’s mind boggling!” Once the COVID-19 infection subsides in the patients, their chronic pain comes back, he said.
Bear in mind, most symptoms are due to our own immune response. The fever, the coughing, the runny nose, are all efforts by our own immune system to defeat the germs. Presumably, these symptoms still occur eventually, despite the pain relief.
I expect covid-pain-killing would not explain most true asymptomatic cases. It may perhaps keep people on their feet shedding germs further during the early days of their disease when they are also the most infectious. True asymptomatic cases probably have some other way to defeat the virus — or who got lucky with a very small dose.
Moutal et al (2020) SARS-CoV-2 Spike protein co-opts VEGF-A/Neuropilin-1 receptor signaling to induce analgesia,
October 10, 2020 at 12:11PM