Neuropathy is usually very difficult to treat, although available medications often have serious side effects. However, researchers from Germany have now found a way to prevent the development of neuropathic pain at an early stage.
Chronic immune response promotes inflammatory pain
Uncomfortable tingling in the hands and feet, numbness, furry and burning – these symptoms can indicate neuropathy, a disease of the nervous system. If the pain persists for several months, it is called chronic. They are then very difficult to treat, and available medications often have serious side effects. Researchers at the translational medicine and pharmacology TMP section of the Fraunhofer Institute for Molecular Biology and Applied Ecology IME have found a way to prevent the development of neuropathic pain at an early stage.
About five million people in Germany suffer from neuropathic pain. They arise from damage to the peripheral or central nervous system. There are many reasons for this: The discomfort often arises after operations, for example after bypass operations, or accidents, for example when the spinal cord is injured. Phantom pain, from which not a few patients suffer after an amputation, is also a neuropathic, mechanically induced pain. A change in skin sensitivity is typical. Stimuli such as cold, heat or touch are felt more or less.
It becomes problematic when the pain becomes independent and chronic. The quality of life of those affected is then significantly impaired. Often they can no longer practice their profession, they neglect leisure activities and friendships. The consequences are isolation, resignation and depression.
The development of neuropathic, trauma-induced pain, which often occurs after surgery or accidents, must be stopped as early as possible. Once the neuropathic pain has arisen, therapies only have a limited effect. In addition, the corresponding drugs have strong side effects.
How immune cells become an enemy
This is where researchers at Fraunhofer IME in Frankfurt come in. They are researching alternative therapies for the early treatment of neuropathic pain. Tests have already shown that various lipids, which are released as signaling molecules in injuries, control the inflammatory reactions on the damaged nerves.
“The nerves raise the alarm and release lipids to signal the immune system that there is an injury and the cause needs to be remedied,” said Prof. Dr. Klaus Scholich, Group Leader Biomedical Analysis and Imaging at Fraunhofer IME: “With neuropathic pain, the attracted immune cells become an enemy after a while. They interact with the nerves in such a way that the affected areas are permanently inflamed. The nerve pain can no longer subside, it will chronic. By disrupting signaling pathways that attract immune cells, we can significantly reduce pain. ”
This is possible, for example, through the timely use of painkillers such as ibuprofen and diclofenac. When administered early, these drugs can stop the production of the lipid prostaglandin E2, which plays a crucial role in trauma-induced pain, as it both sensitizes the nerves and activates the immune system.
Prostaglandin E2 also binds the EP3 receptor. Neurons that have this receptor release the signaling molecule CCL2. This in turn promotes pain development, since it always attracts new immune cells to the injured nerves and also increases pain perception, as the IME researchers found in their studies.
We were able to elucidate the downstream mechanisms that promote the development of neuropathic pain via inflammatory reactions, “continued Prof. Scholich.” The EP3 receptor recognizes prostaglandin E2. By switching off the EP3 and thus inhibiting the release of CCL2, the pain development can be significantly reduced. “The CCL2 could be intercepted with therapeutic, specific antibodies.
These antibodies could be used for chronic pain when conventional medicines such as ibuprofen are no longer effective. The disadvantage: Antibodies have to be injected. Since this is perceived by most patients as unpleasant, Scholich and his colleagues are researching alternative active substances that can be administered orally.
–
