Type 1 diabetes cured in mice using gene therapy

Researchers from the University of Texas Health Science Center in San Antonio have found a way to cure type 1 diabetes in mice. It is hoped that the novel technique - which boosts insulin secretion in the pancreas - will reach human clinical trials in the next 3 years.

Study co-author Dr. Bruno Doiron, Ph.D., of the Division of Diabetes, and colleagues recently reported their findings in the journal Current Pharmaceutical Biotechnology.

Type 1 diabetes is estimated to affect around 1.25 million children and adults in the United States. Onset of the condition is most common in childhood, but it can arise at any age.

In type 1 diabetes, the immune system destroys the insulin-producing beta cells of the pancreas. Insulin is the hormone that regulates blood glucose levels. As a result, blood glucose levels become too high.

There is currently no cure for type 1 diabetes; the condition is managed through diet and insulin therapy. However, in recent years, researchers have investigated replacing beta cells as a means of eradicating type 1 diabetes once and for all.

Dr. Doiron and colleagues have taken a different approach with their new study. The team reveals how they used a method called gene transfer to coax other pancreatic cells into producing insulin.

Using this technique, the researchers have managed to cure type 1 diabetes in mice, bringing us one step closer to curing the condition in humans.

Gene transfer method led to long-term insulin secretion in mice

The gene transfer technique - called Cellular Networking, Integration and Processing - involves introducing specific genes into the pancreas using a virus as a vector.

The team notes that beta cells are rejected in patients with type 1 diabetes. With the gene transfer method, the newly introduced genes encourage non-beta cells to produce insulin, without any side effects.

"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]," says study co-author Dr. Ralph DeFronzo, chief of the Division of Diabetes. "This is basically just like beta cells."

Upon testing their technique on mouse models of type 1 diabetes, the researchers found that they were able to induce long-term insulin secretion and blood glucose regulation, with no adverse side effects.

"It worked perfectly. We cured mice for 1 year without any side effects. That's never been seen. But it's a mouse model, so caution is needed. We want to bring this to large animals that are closer to humans in physiology of the endocrine system."

Dr. Bruno Doiron, Ph.D.

Technique may also help to treat type 2 diabetes

Importantly, the researchers point out that the gene transfer therapy only releases insulin in response to blood sugar, so it has the potential to transform current treatments for type 1 diabetes.

"A major problem we have in the field of type 1 diabetes is hypoglycemia (low blood sugar)," says 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."

Not only could the novel strategy yield a cure for type 1 diabetes, but the researchers say that it may also eliminate the need for insulin therapy in patients with type 2 diabetes, which arises when the body is unable to use insulin effectively.

It will cost around $5 million to test their technique in large animal models, but the researchers are confident that this can be achieved. They hope to reach human clinical trials within the next 3 years.

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