The Joslin Diabetes Center reports that its scientists led by Robert Stanton have discovered that high blood glucose levels damage a key enzyme that guards insulin-producing beta cells. Their finding, which Joslin describes as "surprising," raises hope of finding drugs that can protect the enzymes, which in turn protect the insulin-producing beta cells.
The study, published online in The FASEB Journal, details the cellular process known as oxidative stress that kills off the enzyme and the beta cells.
As a news release describes, cells in the body constantly are churning out poisonous forms of oxygen then mopping them up with proteins and chemicals known as antioxidants. This balancing act of oxidative stress can go haywire in beta cells, which malfunction and start to die off in people with diabetes.
Researcners identified an enzyme known as G6PD, which produces an antioxidant called MAPDH. They showed that NAPDH can regulate the growth and death of beta cells. The Joslin team then demonstrated that increases in blood glucose levels cause a decrease in NAPDH that ends up killing beta cells. At least in the beta cells of laboratory mice, the researchers have shown that by boosting production of the antioxidant, they can guard against beta-cell damage.
"Preventing the death of beta cells or stimulating beta cells to grow is a Holy Grail in diabetes prevention," Dr. Stanton said in the Joslin release. "Treatments aimed at increasing this essential antioxidant holds great promise for treating or preventing diabetes."