A potential cure for Type 1 diabetes looms on the horizon – and the novel approach would also allow Type 2 diabetics to stop insulin shots.
The treatment totally cured diabetes in mice for an entire year without any side effects. The discovery, made at UT Health San Antonio, works by increasing the types of pancreatic cells that secrete insulin.
“It worked perfectly,” said Dr. Bruno Doiron, assistant professor of medicine at UT Health. “We cured mice for one year without any side effects. That’s never been seen.”
Insulin, which lowers blood sugar, is only made by beta cells. In Type 1 diabetes, beta cells are destroyed by the immune system and the person has no insulin. In Type 2 diabetes, beta cells fail and insulin decreases. At the same time in Type 2, the body doesn’t use insulin efficiently.
The therapy is accomplished by a technique called gene transfer. A virus is used as a vector, or carrier, to introduce selected genes into the pancreas. These genes become incorporated and cause digestive enzymes and other cell types to make insulin.
Unlike beta cells, which the body rejects in Type 1 diabetes, the other cell populations of the pancreas co-exist with the body’s immune defenses.
Gene transfer using a viral vector has been approved nearly 50 times by the U.S. Food and Drug Administration to treat various diseases.
“The pancreas has many other cell types besides beta cells, and our approach is to alter these cells so that they start to secrete insulin, but only in response to glucose [sugar],” said co-inventor Ralph DeFronzo. “This is basically just like beta cells.”
The team’s treatment could be a major advance over traditional insulin therapy and some diabetes medications that drop blood sugar too low if not closely monitored.
“A major problem we have in the field of Type 1 diabetes is hypoglycemia (low blood sugar),” said Dr. Doiron. “The gene transfer we propose is remarkable because the altered cells match the characteristics of beta cells. Insulin is only released in response to glucose.”
This is a mouse model, so caution is needed. The researchers have a goal to reach human clinical trials in the next three years, but to do so they must first test the strategy in large-animal studies, which will cost an estimated $5 million. The team received a U.S. patent in January, and UT Health San Antonio is spinning out a company to begin commercialization.