'On-off' switch for major diseases uncovered

London, October 7 : An international team of researchers has discovered a novel receptor that appears to act as an "on-off" switch for several major diseases.

The researchers say that the GPR91 receptor contributes to activate unchecked vascular growth that causes vision loss in common blinding diseases.

According to them, the new discovery can have wide-ranging and positive implications for brain tissue regeneration.

The research team-consisting of scientists from Sainte-Justine Hospital Research Center, the Universite de Montreal and the Institut national de la sante et de la recherche medicale (INSERM) in France-said that it was while investigating the molecular mechanisms that lead to vision loss that they found that the GPR91 receptor could mediate irregular vascular growth, which is responsible for some of the main causes of blindness in the industrial world.

"We found that GPR91 is a master regulator of blood vessel growth, which upon enhanced activation leads to the unchecked and anarchic proliferation of vascular networks, which is the hallmark of retinopathies. This uncontrolled overgrowth can ultimately cause the retina to detach and a person to lose their sight," Nature magazine quoted Dr. Mike Przemyslaw Sapieha, the study's lead author and a scientist at the Sainte-Justine Hospital Reserch Center and the Universite de Montreal, as saying.

"With the identification of GPR91 as a key player in this disease process, we can move forward in designing treatments that block the receptor and consequently stop vision loss. Inhibition of GPR91 has a great therapeutic potential to halt these blinding diseases," added Dr. Sapieha.

The researchers even said that the GPR91 receptor could preserve neurons.

"Neurons are key sensors in retina oxygenation and serve as key players in the repair process of the retina," said Dr. Sylvain Chemtob, director of the study and a neonatal researcher at the Sainte-Justine Hospital Research Center and professor at the Universite de Montreal's Department of Pediatrics, Ophthalmology, Pharmacology and the School of Optometry.

"Given the similarities between the retina and the brain, we can envisage applying our findings in retina to the brain. Activation of the GPR91 receptor could be beneficial in helping salvage neurons in damaged brain tissue in stroke or head injury victims," added Dr. Chemtob.

The GPR91 also appears to respond to stresses, and adjust when in its oxygenation state is compromised.

"This is a new concept in vascular biology. If you stop GPR91 from allowing blood vessels to expand and supply a tumour with nutrients and oxygen, one can significantly hamper growth of the cancer," says Dr. Sapieha, noting it is conceivable that interfering with the GPR91 receptor could be used to stop cancer growth.

Although the promising findings result from animal studies, GPR91 is also found in humans.

Dr. Chemtob surmises that extension of the research to human clinical investigations could be in three to fours years.

"We expect these findings to have an enormous impact," he says.

The findings have been published in the journal Nature Medicine.

ANI