A new research has suggested that coronavirus may act like a pain relief, causing the illness not to show symptoms in its early stages while it spreads in the body.
In the research which was conducted on mice, scientists figured out that the virus uses a protein spike to enter cells, the protein spike attaches itself to a receptor and completely inverts the pathway of neurons that signals pain.
The research revealed that pain relief could begin within 30 minutes after the infection and last for hours or days.
The researchers from the University of Arizona Health Sciences says the results of the research may explain why nearly half of the coronavirus patients showed no indications.
The researchers revealed that the spike protein on the outside of the virus attaches to a receptor known as neuropilin-1. It was revealed that the instead of causing pain, it actually blocks the pain pathway.
The research which was done on laboratory mice, from the University of Arizona Health Sciences , revealed that when the spike protein attached to the neuropilin receptor in the mice, the mice felt no pain within 30 minutes.
Dr Rajesh Khanna, corresponding author, professor in the department of pharmacology at the University of Arizona College of Medicine announced that the research may also reveal how the virus spreads so quickly.
“It made a lot of sense to me that perhaps the reason for the unrelenting spread of COVID-19 is that in the early stages, you’re walking around all fine as if nothing is wrong because your pain has been suppressed,” he explained in a statement.
“You have the virus, but you don’t feel bad because your pain is gone. If we can prove that this pain relief is what is causing COVID-19 to spread further, that’s of enormous value.”
A protein known as the vascular endothelial growth factor-A (VEGF-A), attaches to neuropilin-1 receptor when pain is felt by humans. The attachment causes a series of reactions that cause neurons to become overexcited, this reaction produces pain.
‘That caught our eye because for the last 15 years my lab has been studying a complex of proteins and pathways that relate to pain processing that are downstream of neuropilin. ‘ Khanna explained.
‘So we stepped back and realized this could mean that maybe the spike protein is involved in some sort of pain processing.’
The researchers then decided to test if the virus can relieve pain in more than a 100 mice. This development was published in the journal PAIN.
An inactivated spike protein of the virus was injected in half of the mice, the inactive spike protein could still attach to the receptor but would not cause infection. The other half of the mice was then injected with placebos.
Half of the mice which were injected with spike were relieved of pain in 30 minutes and lasted for at least 9 hours.
‘The spike protein completely reversed the VEGF-induced pain signaling,’ sighted Khanna.
‘It didn’t matter if we used very high doses of spike or extremely low doses – it reversed the pain completely.’
The researchers then planed to look at whether neuropilin-1 could serve as medication for pain relief in the future.
‘We are moving forward with designing small molecules against neuropilin, particularly natural compounds, that could be important for pain relief,’ Khanna explain
‘We have a pandemic, and we have an opioid epidemic. They’re colliding. Our findings have massive implications for both’, he added.
‘SARS-CoV-2 is teaching us about viral spread, but COVID-19 has us also looking at neuropilin as a new non-opioid method to fight the opioid epidemic.’