March 1, 2012

Early study hints at fat as potential diabetes treatment

Early study hints at fat as potential diabetes treatment

Researchers at Vanderbilt University have reversed type 1 diabetes in mice with transplants of brown fat tissue.

The findings, published in the March issue of the journal Diabetes, imply that “long-lasting reversal of diabetes is possible without insulin,” said David Piston, Ph.D., the paper’s senior author.

Piston, the Louise B. McGavock Chair and professor in the Department of Molecular Physiology & Biophysics, conducted the research with Subhadra Gunawardana, Ph.D., research assistant professor in the department.
The study was based on recent findings that indicate hormone-like molecules secreted by fat tissue, such as adiponectin, leptin and IGF-1 (insulin-like growth factor), “may be able to compensate for a loss of insulin,” the Vanderbilt researchers wrote.

If — in the future — this approach can be shown to work in humans, it "could constitute a legitimate cure," they concluded.

Brown adipose (fat) tissue helps keep the body warm by burning fat molecules. It is distinguished from white fat tissue, which accumulates fat molecules, but both tissues secrete important hormone-like factors that may be important in diabetes.

Type 1 diabetes results from the autoimmune destruction of insulin-producing beta cells in the pancreas. The disease also is associated with chronic inflammation and loss of white fat tissue.

Current treatments for diabetes include insulin injections or beta-cell transplants, both of which “suffer from numerous limitations and complications,” the researchers wrote.

In the Vanderbilt study, embryonic brown fat tissue was transplanted under the skin of diabetic mice.

In less than two weeks, glucose control markedly improved and the diabetes reversed. The benefits lasted for at least six months, the researchers reported.

As blood glucose levels normalized, inflammation also declined and white fat tissue regenerated. This may be due to IGF-1, which is secreted by both fat tissues, and by other factors released by brown tissue that have anti-inflammatory properties, Gunawardana said.

The reversal of diabetes was accompanied by weight gain, but the mice did not become obese.

“When brown adipose tissue is present, white adipose tissue seems to accumulate fat less,” she noted. “This has implications for obesity therapy.”