Muscle Relaxer May Help Treat Rare Form of Diabetes

Dantrolene found to help prevent the destruction of insulin-producing beta cells in patients with Wolfram syndrome.

A commonly used muscle relaxer may help protect patients suffering from a rare form of diabetes, a recent study showed.

The drug dantrolene was found to halt the destruction of insulin-producing beta cells in animal models and in cell models from patients who have Wolfram syndrome. The illness requires insulin injections several times daily, and can also cause hearing and vision problems, and difficulty balancing.

In a study published online November 24, 2014 in the Proceedings of the National Academy of Sciences, researchers found elevated levels of the calpain 2 enzyme to be chiefly responsible for the death of brain cells and insulin-producing cells. The study determined that dantrolene is able to block the calpain 2 enzyme, while also preventing brain cell death in both animal and cell models of the disease.

"We'd like to test the drug first in adult patients with Wolfram syndrome, and if we get positive results, we could extend the trial to children," said senior investigator Fumihiko Urano, MD, PhD, in a press release.

The drug is typically used to treat muscle spasticity in cerebral palsy or multiple sclerosis patients. If the treatment is deemed effective in Wolfram syndrome patients, dantrolene may also provide an option for patients with common forms of diabetes. The study noted that calpain 2 is overactive in cell models of those common forms of the disease.

Additionally, the researchers evaluated the impact of dantrolene on stem cells grown from the skin cells of Wolfram syndrome patients and their close relatives. The stem cells from Wolfram patients generated high levels of calpain 2, which subsequently induced cell death.

When those cells were treated with dantrolene, however, levels of calpain 2 decreased and the cells stopped dying.

"We also found that dantrolene was not toxic to cells grown from the skin samples donated by patients' relatives," Dr. Urano said. "The drug interfered with cell death in cells from Wolfram patients but did not harm cells that came from parents and siblings."

Additional studies will evaluate whether dantrolene may provide an effective treatment for type 1 and type 2 diabetes.

"Wolfram is the most difficult form of diabetes because these patients have problems with blood sugar and so many other challenges," Dr. Urano concluded. "Calpain 2 also plays a role in type 1 and type 2 diabetes. Currently, we are studying the drug in animal and cell models of those types of diabetes to see if it also keeps insulin-producing cells from dying."