Research groups at Kyushu University Graduate School, Okayama University, and Johns Hopkins University (USA) discovered for the first time in the world that repeated scratching of itchy skin increases the protein called NPTX2 in nerves, which enhances the activity of itchy signaling nerves. bottom.
When we feel itchy, we scratch the itchy area.Normally, itching will subside after several scratches, but if it is chronically intense itching associated with atopic dermatitis or contact dermatitis, it will be scratched over and over again.This exacerbates the inflammation of the skin, resulting in a vicious cycle of further itching.This is called the "vicious circle of itching and scratching" and is considered to be a major cause of prolonged itching, but the mechanism is not well understood.
The research group conducted research on atopic dermatitis and contact dermatitis model mice that scratch the skin over and over again, and the activity of the spinal nerve (itch transmission nerve) that sends the itching signal from the skin to the brain is increasing. We found that it did not occur when the scratching irritation to the skin was suppressed.Furthermore, it was discovered that by repeatedly scratching the skin, a protein called NPTX2 increases in the sensory nerve that connects the skin and the spinal cord, and when this protein acts on the itching transmitting nerve of the spinal cord, the activity of that nerve increases.In fact, in mice lacking NPTX2, the activity of the itchy signaling nerves in the spinal cord was reduced and itching was alleviated.
In the future, if a compound that suppresses the increase of NPTX2 in nerves or a compound that inhibits the action of NPTX2 is found, the development of an effective therapeutic drug for chronic itching caused by atopic dermatitis and contact dermatitis. It is expected to lead to.
