Scientists discover unexpected role of white blood cells in diabetes

A new study has revealed that a type of white blood cell that attacks bacteria and other foreign invaders may also have a key role in the development of type 2 diabetes.
Using liver and fat cells from mice and humans and live mouse models, researchers at the University of California, San Diego School of Medicine, found that neutrophils also secrete a protein known as neutrophil elastase (NE) that boosts insulin resistance.
This diabetes-related condition occurs when sustained high levels of blood glucose reduce the body’s sensitivity to the hormone insulin, and is closely linked with inflammation.
The scientists discovered that neutrophils can promote chronic inflammation by recruiting other white blood cells called macrophages.
Specifically, neutrophils, signal NE to trigger macrophages to release pro-inflammatory chemicals known as cytokines. NE also breaks down a key protein in the insulin signaling pathway in the liver and fat cells known as IRS1, according to the study.
“These results are largely unexpected,” said study co-author Da Young Oh. “Although several immune cells have been established in the etiology of insulin resistance, the role of neutrophils in this process has remained unclear until now. Our studies now suggest neutrophils possess powerful immune modulatory effects.”
Oh said the discovery could mean a new target for drugs aimed at reversing or improving insulin resistance, adding that NE inhibitors are already used for treatment of emphysema in Japan and are being tested in the US for both emphysema and type 1 diabetes.