Research on Nerve Injury Recovery and Pain Management
Researchers at The University of Texas MD Anderson Cancer Center have identified a specific immune process as a potential target to improve recovery following nerve injury and reduce chronic pain. The findings were published in the Proceedings of the National Academy of Sciences (PNAS). The study was led by Peter Grace, Ph.D., an associate professor of Symptom Research.
Peripheral Neuropathy and Macrophage Function
The study indicates that peripheral neuropathy, a condition resulting from nerve injury, diminishes the capacity of macrophage immune cells to clear dead or dying cells, a process known as efferocytosis. This reduction in efferocytosis is associated with the development of chronic pain. The research suggests that modulating efferocytosis could offer a viable treatment approach.
Peripheral neuropathy involves damage to the peripheral nervous system, leading to inflammation and chronic neuropathic pain. This condition affects a significant global population.
Macrophages are immune cells that contribute to preventing inflammation and repairing nerve damage. They utilize MERTK receptors to identify "eat me" signals on dead or dying cells. These cells can transition from a pro-inflammatory to an anti-inflammatory state and engulf dead cells through efferocytosis.
Study Discoveries
The researchers demonstrated that nerve injury triggers the release of proteins that remove the MERTK receptor from macrophages, resulting in decreased efferocytosis in laboratory models. This reduction was observed in conjunction with chronic pain, neuronal hyperactivity, nerve and tissue damage, and ongoing inflammation. The restoration of macrophages' ability to clear dead cells was shown to reduce neuropathic pain and enhance tissue repair in these models.
Clinical Implications
These preclinical findings propose that stimulating efferocytosis represents a potential therapeutic strategy. Such an approach could aim to prevent inflammatory signaling, enhance nerve repair, and resolve neuropathic pain in patients experiencing nerve injury.
This research is conducted within MD Anderson's Cancer Neuroscience Program.