Detecting genes that cause itching

Scientists have identified the first gene in the central nervous system that causes itching. Although other itchy genes have been known, this is the first gene that is directly linked to the brain and paves the way for new drugs to ease the severe itching.

GRPR protein causes itching (red) in part of the spine. (Photo: Yan-Gang Sun and Zhou-Feng Chen, Nature)

The culprit caused by this gene is the gastrin-producing peptide receptor (GRPR). Scientists have been studying this gene for its role in pain but no one has ever linked it to itching.

A research group led by geneticist Zhou-Feng Chen in St. Louis Louis, Missouri began studying GRPR because the group was very interested in the genes causing pain. GRPR is only detected in some spinal nerve cells, cells send pain and itching signals to the brain.

The team soon discovered that this receptor is not essential for identifying pain; The mice with the GPRE gene were anesthetized before responding normally to other types of pain. Later, the scientists examined whether GRPR is necessary to feel itchy by injecting some itchy compounds into anesthesia mice, including histamine, a substance that causes itching due to allergy.

These anesthetized mice did not scratch anywhere, nearly the same as other normal mice in response to injections. In contrast, when scientists injected a peptide mimic that produced gastrin or GRPR into normal mice, they scratched even more.

The authors believe that this signal will bring about a promising new result for chronic itching. This often hard to cure problem comes from many diseases, from skin disorders to tumors.

(Photo: Pennhealth)

Thanh Van