When nerves are damaged it can cause a condition called peripheral neuropathy. Symptoms include a feeling of pins and needles, weakness, and numbness, particularly in the hands and feet.

Dr. Sandra Rieger, peripheral neuropathy/diabetes researcher

In 2016, I wrote a blog post about Dr. Sandra Rieger’s research on how and when peripheral neuropathy starts when someone is on chemotherapy.  Dr. Rieger is a scientist at Mount Desert Island Biological Laboratory (MDIBL) in Bar Harbor.

From research she did on zebrafish she discovered that nerve damage from at least one chemotherapy drug — Taxol — begins in the outer layer of the skin. An overabundance of a certain enzyme causes the matrix between skin cells and the collagen or “glue” that holds them together to break down or degenerate. Dr. Rieger and her team also found two drug candidates that prevented and reversed peripheral neuropathy caused by Taxol. 

In new research, Dr. Rieger has discovered that the same enzyme connected to certain chemotherapy drugs also plays a role in peripheral neuropathy caused by diabetes. Chemotherapy is the second leading cause of peripheral neuropathy; diabetes is the first.

The two drug candidates her team discovered in earlier research worked on peripheral neuropathy caused by chemotherapy, but what about diabetes? Dr. Rieger tested the effectiveness of one of the two compounds on mice that were fed a high fat/sugar diet in order to induce diabetes. The mice research was conducted in collaboration with Dr. Kristy Townsend, an assistant professor of neurobiology at the University of Maine.

Dr. Rieger’s study, which was published in the Journal of Diabetes and its Complications, showed that the drug candidate was not only effective in zebrafish, but also in mice. “The fact that this compound works in two such disparate species makes it more likely it will work in humans too,” said Dr. Rieger.

Right now there are treatments for easing neuropathy pain but not to prevent or reverse nerve degeneration. The challenge has been trying to understand the underlying mechanisms that lead to the nerve damage. Dr. Rieger’s findings are significant and hopefully, will someday lead to effective treatments for humans.

“Peripheral neuropathy is a major and growing health problem,” said MDIBL president Dr. Kevin Strange. “The identification of the mechanism underlying glucose-induced peripheral neuropathy means that millions of patients could potentially benefit from the development of drugs that influence this pathway.”

Next steps include delving more deeply into the mechanisms that cause peripheral neuropathy in people with diabetes, searching for additional drug candidates, and testing them on humans. I’ll keep you posted.