Discovery Suggests Potential Treatment for Type 2 Diabetes

Researchers have found that adipsin, a fat-generated protein, improves insulin secretion in mice.

According to the American Diabetes Association, diabetes affects more than 25 million adults and children in the United States. In fact, 1.9 million new diagnoses are made each year. But a recent discovery by researchers at Harvard Medical School and Dana-Farber Cancer Institute may provide new hope for those with type 2 diabetes.

In a study published in the July 3 issue of Cell, investigators found that a fat-generated protein, adipsin, plays an important role in stimulating insulin secretion to control blood sugar. The study also revealed that humans with severe type 2 diabetes lack this protein, which results in the malfunction of beta cells in the pancreas.

According to an HMS report:

Lower levels of adipsin had been reported in obese and diabetic animals, but levels were unchanged or elevated in overweight and diabetic humans, leaving unclear how the protein functions in those conditions.

In this study, the Dana-Farber investigators used “knockout” mice lacking the adipsin gene and “wild-type” mice with normal adipsin levels. Both types of animals became obese on a high-fat diet and developed excess blood sugar—a prediabetic state. The symptoms were worse in the adipsin knockout mice than the wild-type animals, which had normal adipsin activity.

In the [study], the scientists noted that the difference in symptoms is explained by “an unexpected and striking requirement of adipsin for proper insulin secretion by the pancreatic beta cells.”

Though the experiment was conducted with mice, researchers believe the results may have significant implications for humans.

“This suggests a new approach to treating type 2 diabetes in patients whose pancreatic beta cells work poorly, leaving them dependent on injected insulin,” senior study author Bruce Spiegelman said in the report. “If humans respond similarly to the mice in this study, correcting their deficiency of adipsin would improve beta cell function and perhaps maintain enough natural insulin production to avoid or delay having to take additional insulin.”