Scientists have discovered bitter taste receptors in an unexpected part of the body – the walls of blood vessels in the lungs. The find could be an important new drug target to treat acute respiratory distress syndrome (ARDS), a dangerous complication of many diseases.
ARDS is characterized by excess inflammation and fluid in the lungs. It can be caused by pneumonia, sepsis, and more recently, COVID-19, and often results in patients requiring intensive care and mechanical ventilation. It has a high mortality rate of around 40 percent, and those who do survive often experience a lower quality of life afterwards.
A new study led by researchers at Anglia Ruskin University (ARU) has now uncovered a previously unknown mechanism that allows fluid to build up in the lungs – and more importantly, a potential way to prevent it.
The team discovered that bitter taste receptors, normally found in the tongue, were also present in cells lining blood vessels of the lung. Stranger still, they seem to regulate how these blood vessels function under stress. That implied an intriguing link to ARDS, which is known to increase the permeability of blood vessels, allowing proteins and liquids to pass through into the lungs.
The team tested the idea by knocking out the genes for two of these receptors, T2R38 and T2R10, and found that the vessels became more permeable. Inversely, when they stimulated the receptors with bitter compounds, they formed a stronger barrier and prevented fluids from passing through. The researchers say this discovery could open a new drug target for future treatments for ARDS.
“When we stimulate these proteins, we have found that they offer protection against fluid leak,” said Dr. Havovi Chichger, senior author of the study. “These findings indicate that this new family of proteins in blood vessels could offer a new avenue of drugs to reduce fluid leak into the lung, and therefore help to treat patients with respiratory distress.”
The research was published in the journal Frontiers in Physiology.
Source: ARU