Study Ties Dysfunction of a Single Gene to Type 2 Diabetes

Researchers have found that the dysfunction of a single gene can be associated with symptoms of type 2 diabetes in mice.

Documented in the journal Diabetes, the researchers at the University of Illinois at Chicago College of Medicine discovered that the loss of function of a single gene called MADD triggered  hyperglycemia in mice, one of the major symptoms of type 2 diabetes.

The lead author of the paper, Bellur S. Prabhakar, explains that due to the improper functioning of the gene MADD, insulin is not released into the bloodstream to regulate the levels of blood sugar. 

The beta cells in a healthy person's pancreas secrete the hormone insulin , which controls the blood glucose levels.  Those with Type 2 diabetes fail to produce sufficient insulin to control glucose levels.

Prior to this, the researcher had isolated multiple genes from the human beta cells including MADD. The researcher noticed minute genetic variations in thousands of human subjects and disclosed that mutation in MADD was tied with type 2 diabetes in Europeans and Han Chinese.

To investigate how mutation triggered these symptoms, they studied the role of MADD in diabetes.

For this they developed a mice model where the MADD gene was removed from the beta cells. The researchers noticed that these mice had elevated blood glucose levels, mainly due to lack of sufficient insulin release.

"We didn't see any insulin resistance in their cells, but it was clear that the beta cells were not functioning properly," Prabhakar said. "Examination of the beta cells revealed that they were packed with insulin. The cells were producing plenty of insulin, they just weren't secreting it."

This makes it evident that Type 2 diabetes can be directly triggered by damage to a properly functioning MADD gene alone.

"Without the gene, insulin can't leave the beta cells, and blood glucose levels are chronically high," he said.

The team plans to investigate the effect of a drug that permits the secretion of insulin in MADD-deficient beta cells.

According to Centers of Disease Control and Prevention (CDC) an estimated 25.8 million people in the United States (8.3% of the population) have diabetes.