New Gene Therapy Technique for Potential Treatment of Type I Diabetes

Researchers at Baylor University Medical Center at Dallas and the Baylor Research Institute have developed a novel technique to deliver insulin genes to the pancreas, the organ that produces the body's insulin. This approach is a major step in the potential treatment of Type I diabetes since patients with the disease do not produce enough insulin on their own. The research results were published in the May 2006 issue of the Proceedings of the National Academy of Sciences.

Insulin is a hormone that allows blood glucose (blood sugar) to enter the cells of the body to be used for energy. The technique, known as ultrasound-targeted microbubble destruction (UTMD), delivers these insulin genes to the organ via microscopic "bubbles." Once the bubbles reach their target, they are burst with ultrasound releasing the insulin genes into the pancreas.

Using UTMD, researchers delivered the bubbles containing human insulin genes into the pancreas of rats and later found that the rat's blood sugar had been subsequently lowered. Another gene that regulates insulin production, known as hexokinase I, was successfully delivered using UTMD as well, and resulted in increased blood insulin and decreased blood sugar in the rats.

"Not only was their blood sugar lowered, but there was no evidence of any damage to the pancreas," says Paul Grayburn, M.D., principal investigator of the study. "Other forms of gene therapy are usually invasive and unlike the UTMD technique, do not target the tissues and organs specifically."

Currently, patients with Type I (juvenile onset) diabetes must inject themselves with insulin daily to keep their blood sugar levels balanced in addition to following strict nutritional guidelines. Dr. Grayburn says that the UTMD technique is one of the most important steps in the development of a successful treatment of diabetes without the need for daily insulin injections.

"Now that we have successfully delivered insulin genes to the pancreas, our ultimate goal is to research the regeneration of insulin-producing cells in patients with Type I diabetes," says Dr. Grayburn.

In the future, Dr. Grayburn says that the UTMD technique for gene delivery can be used to deliver therapeutic agents to other organs as well.

Nationwide, more than one million people have Type 1 (juvenile onset) diabetes. Diabetes - the fifth deadliest disease in the United States - affects the body's ability to produce or respond to insulin. People with Type 1 diabetes are at increased risk for many serious complications, including heart disease, blindness, nerve damage and kidney damage.

Dr. Grayburn's research was supported by a grant from the National Institutes of Health and by the Mary Alice M. and Mark Shepherd, Jr. Endowment Fund in Cardiology and Cardiovascular Surgery and Research. The study was also held in conjunction with researchers from Duke University and UT Southwestern Medical Center.