In both Type 1 and Type 2 diabetes, beta cells — the insulin-producing cells in the pancreas — play a key role in the development of the condition. In the case of Type 1 diabetes, an autoimmune condition, the cells are destroyed by the immune system. In Type 2 diabetes, the beta cells cannot keep up with the demands of insulin resistant cells in the body. As a result, more than 7 million people in the United States rely on daily injections or infusions of insulin to keep their blood sugar in target range. But new JDRF-funded research from Joslin Diabetes Center has identified an important protein in the liver that helps accelerate beta cell growth, pointing toward a possible method for treating all types of diabetes.
Previous research in insulin-resistant mice had shown that proteins being released from the liver and circulating in the blood were causing increased growth of beta cells. In the current study, the team first investigated these proteins, finding especially high levels of a protein known as serpinB1. Next, they incubated mouse and human islets (which contain beta cells) with a manmade version of serpinB1, and discovered that new beta cells grew. Finally, the team worked with mice that had been genetically altered to not produce serpinB1, then exposed them to two situations that are known to increase beta cell production in normal mice. In both cases, the mice did not grow as many new beta cells as mice with serpinB1.
A collaborating research team found that, in zebrafish with high levels of the serpinB1 protein, there were especially high levels of beta cell growth, and that even when the fish where given a mixture that destroyed all their beta cells, new ones continued to grow. “This may have particular implications for treating Type 1 diabetes, in which most of the beta cells are gone,” states senior investigator Rohit N. Kulkarni, MD, PhD.
Adding to the evidence of serpinB1’s role in beta cell production, investigators found a link between insulin resistance and levels of serpinB1 in the blood of 49 people examined at Joslin.
The scientists are currently looking at more people with diabetes to evaluate levels of serpinB1 in the blood and are researching exactly how it increases beta cell growth.
“Making more functional beta cells is critical for treating all forms of diabetes,” notes Kulkarni. “We look forward to moving ahead rapidly with work to translate this research toward clinical use.”
For more information, see the press release on the Joslin Diabetes Center website or see the study’s abstract in the journal Cell Metabolism. And to learn more about research into restoring beta cells, see “Can Beta Cells Be Healed?” by nurse David Spero.
If you’re between the ages of 18 and 35 and are in a romantic relationship, you may be interested in an online survey from researchers at Texas Tech University. Bookmark DiabetesSelfManagement.com and tune in tomorrow to learn more.
