Study Finds Macrophages Play Protective Role in Trying to Prevent Neuropathy

A new study from Boston Children's Hospital reveals an unexpected role of macrophages in preventing peripheral nerve damage associated with type 2 diabetes. The research, published in Nature, challenges previous assumptions about the immune system's role in diabetic neuropathy and opens up potential avenues for prevention and treatment.

Using a mouse model of diabetes induced by a high-fat, high-fructose diet, researchers observed that macrophages infiltrate peripheral nerves months before visible nerve damage occurs. This infiltration appears to be a protective response rather than a harmful one.

"To our great surprise, when we blocked infiltration of macrophages into the nerve, neuropathy started getting worse, not better," says Clifford Woolf, senior author of the study. "The macrophages were protective. They slowed down the onset of neuropathy and reduced its impact."

The study found that pro-inflammatory macrophages residing in nerves produce chemokines, which recruit a second population of circulating macrophages. These infiltrating macrophages appear to play a protective role, potentially slowing the progression of neuropathy.

This insight could lead to new strategies for preventing or minimizing peripheral neuropathy in diabetic patients. Potential approaches might include accelerating macrophage recruitment into nerves or mimicking their protective function using compounds they secrete, such as galectin 3.

The research also underscores the complex interplay between the nervous and immune systems in pain conditions. As Woolf notes, "We've now revealed a novel, slower protective effect of the immune system."