Researchers identify gene linked to diabetes

Using the latest DNA chip technology investigators first identified genes that were altered in their level of expression in islets isolated from people with type 2 diabetes.

The researchers then went on to show that when they created a defect in one of these genes called ARNT (aryl hydrocarbon receptor nuclear translocator) in mice, the animals developed alterations in insulin secretion that were like those in humans with type 2 diabetes.

The ARNT gene is a member of a family of transcription factors essential for normal embryonic development and also is involved in response to conditions of hypoxia and certain environmental toxins, such as dioxin.

Transcription factors like ARNT control the expression and activity of many other genes in the cell and thus serve as master regulators of cell function. As a component of the response to toxins and hypoxic stress, ARNT is also at a potential site to integrate genetic and environmental insults.

“These findings provide new insights into the pathogenesis of the most common forms of type 2 diabetes and a possible new target for treatment of this disease,” said Ronald Kahn, president and director of Joslin Diabetes Center and lead investigator on the research team.

The scientists went on to demonstrate that reducing the level of the ARNT gene in beta cells in culture also produced defects in glucose-stimulated insulin release and alterations in islet gene expression that mimic those in humans with type 2 diabetes.