Giving brown fat a boost to fight type 2 diabetes

Image

By taking advantage of this natural system, we may be 0061ble to help make fat depots more metabolically healthy and potentially prevent or treat obesity-associated diabetes," says study leader Perry E. Bickel, M.D., associate professor of internal medicine at UTSW.

Tens of millions of Americans have Type 2 diabetes, a disease characterized by elevated blood sugar and resistance to insulin, the hormone that allows cells to use blood sugar for energy. This disease has been linked to obesity, with excess white adipose tissue (WAT)—fat tissue that holds the majority of the body's stored energy—associated with elevated blood sugar and insulin resistance in susceptible people. Humans and other mammals also have a second type of fat, known as brown adipose tissue (BAT), which is able to burn fat as a way to increase body heat in cold temperatures. BAT has been investigated as a potential target for weight loss, says Bickel, but may also have a role in improving blood sugar independent of weight loss.

In the study, Bickel and his colleagues, including co-leader Violeta I. Gallardo-Montejano, M.D., an instructor at UTSW, found that brown fat could play an important protective role against diabetes. The researchers made this discovery while studying perilipin 5 (PLIN5), a protein that coats lipid droplets inside cells, particularly in BAT.

When the team genetically engineered mice that made extra PLIN5 in BAT, the animals maintained significantly lower blood sugar concentrations and higher insulin sensitivity during glucose tolerance tests, compared with mice with normal PLIN5 levels. They also had less fatty livers, a condition associated with Type 2 diabetes.

Searching for the mechanism behind these positive changes, the scientists found that the BAT's mitochondria in the genetically engineered mice had adapted to burn even more fat, similar to what's seen in animals placed in cold temperatures. However, the adaptation wasn't enough to explain the blood sugar-lowering effect. Looking closer, the researchers found that the white adipocytes of animals that had extra PLIN5 in their brown adipocytes were smaller and had reductions in some markers of inflammation—changes that are associated with improved sensitivity to insulin and metabolism of sugar.

Bickel notes that BAT appears to communicate with WAT in some unknown way, potentially sending a molecular factor through the bloodstream when PLIN5 levels increase inside brown adipocytes.

Pancreatic disorders and Therapy is now accepting submissions on this topic. A standard EDITORIAL TRACKING SYSTEM is utilized for manuscript submission, review, editorial processing and tracking which can be securely accessed by the authors, reviewers and editors for monitoring and tracking the article processing. Manuscripts can be uploaded online at Editorial Tracking System (www.longdom.org/submissions/pancreatic-disorders-therapy.html ) or forwarded to the Editorial Office at manuscripts@longdom.org

 

Regards,

Jessica Celina

Managing Editor

Pancreatic disorders and Therapy