Nerve stimulation can speed healing of inflammation

It is already known that the nervous system communicates with the immune system and regulates inflammatory processes in the body, but how this regulation works has not been clear.

Previous research at the Karolinska Institutet showed that electrical stimulation of the so-called vagus nerve in the autonomic nervous system can reduce inflammation. Such nerve stimulation has been used with good results in studies of patients with IBD and rheumatoid arthritis. However, the way in which nerve signals regulate active healing processes in inflammatory conditions is unknown.

But now researchers have studied how signals are transmitted between nerves and immune cells at the molecular level.

More knowledge about these mechanisms is needed to understand and refine methods of nerve stimulation that are now being tested in clinical studies, says April Karavaca, a researcher in the Department of Medicine at Karolinska Institutet.

The healing process becomes shorter

By studying genetically modified cells and mice, the researchers were able to show that electrical stimulation of the vagus nerve in acute inflammation alters the balance between inflammatory and anti-inflammatory molecules.

In this way, the healing phase becomes shorter and the inflammation ends more quickly. Electrical stimulation activates a special chemical signal to the nerve and an enzyme important for producing substances that treat inflammation.

Inflammation and the subsequent healing process are central to our defense against infection, among other things, and play a major role in diseases such as rheumatism, inflammatory bowel disease, and atherosclerosis. Our findings could open up new avenues for treating pathological inflammation and speeding recovery by activating now-defined nerve signals and signaling pathways, says Peder Olofsson.

Signal networks must be set

The researchers now plan to go ahead and study more details about how nerve activation is regulated to heal inflammation.

At the molecular level, we are trying to map the neural signaling networks that regulate inflammation, and to understand how disturbances in signaling cause diseases. We hope this knowledge will provide an opportunity to better understand how inflammatory diseases arise and lead to more effective treatments, says Peder Olofsson.

Scientific study:

Stimulation of the vagus nerve promotes resolution of inflammation through a mechanism that involves Alox15 and requires the α7nAChR . subunit. PNAS.

Contact:

Peder Olofsson, associate professor and medical specialist. Department of Medicine at Karolinska Institutet, [email protected]