Diabetes and the Brain — In research published in the August 3 issue of Nature Medicine, Dr. Dongsheng Cai identifies a mechanism that may help explain the brain’s role in causing type 2 diabetes. Studying obese and aged mice—conditions associated with diabetes—Dr. Cai’s team found increased levels of a molecule called transforming growth factor beta (TGF-β) within the hypothalamus of their brains. Then, using a combination of genetic and drug therapies, the researchers increased brain TGF-β levels and observed diabetes-like effects, including increased blood glucose levels. The increase in glucose arose because the liver was unable to stop making it. Further experiments revealed that a particular type of brain cell—POMC neurons—was crucial for allowing TGF-β to cause increased blood glucose levels. TGF-β acting through POMC also activated the molecule NF-κB, which is known to link obesity and aging to hypothalamic inflammation. Dr. Cai is professor of molecular pharmacology.
Posted on: Wednesday, August 20, 2014