inflammation leads to insulin resistance in type 2 diabetes. By removing the protein galectin-3 (Gal3), a team of investigators
led by University of California School of Medicine researchers were able
to reverse diabetic insulin resistance and glucose intolerance in mouse
models of obesity and diabetes.
By binding to insulin receptors on cells, Gal3 prevents insulin from attaching to the receptors resulting in cellular insulin resistance. The team led by Jerrold Olefsky, professor of medicine in the Division of Endocrinology and Metabolism at UC San Diego School of Medicine, showed that by genetically removing Gal3 or using pharmaceutical inhibitors to target it, insulin sensitivity and glucose tolerance could be returned to normal, even among older mice. However, obesity remained unchanged.
"This study puts Gal3 on the map for insulin resistance and diabetes in mouse model," said Olefsky, associate dean for scientific affairs and senior author of the study. "Our findings suggest that Gal3 inhibition in people could be an effective anti-diabetic approach."
Furthermore, investigators identified bone marrow-derived macrophages as the source of Gal3 that leads to insulin resistance. More importantly, researchers found that Gal3 is secreted by macrophages, and can then cause insulin resistance in liver, fat cells, and muscle cells independent of inflammation.
Gal3 has previously been connected to other diseases. Olefsky will continue to study Gal3 depletion as a possible therapeutic target for nonalcoholic steatohepatitis as well as heart and liver fibrosis.