Newly Discovered Irisin Hormone Could Be Developed as Treatment for Obesity, Diabetes
Researchers at the Dana-Farber Cancer Institute have discovered a hormone created in the body which could have very important implications on human health. The protein, which they are calling “irisin” is being described as a highly promising candidate for the development of a novel treatment for diabetes, obesity, and perhaps neurological diseases such as Parkinsons.
Dr. Bruce Spiegelman PhD, a cell biologist, and Pontus Bostrom MD PhD, a postdoctoral fellow, discovered a chemical protein which is produced in muscles during exercise called PGC1-alpha. This compound regulates genes involved in energy metabolism. It may also be involved in controlling blood pressure, regulating cellular cholesterol, and the development of obesity.
The presence of PGC1-alpha causes production of a chemical messenger first known as Fndc5, which researchers renamed to “irisin” after the Greek messenger goddess Iris. This hormone, located within the outer membrane of muscle cells, appears to help convert white fat, which is used to store energy, into brown fat which burns calories.
Dr. Spiegelman injected irisin into obese, diabetic laboratory mice and the hormone did indeed switch on genes that would help burn fat, just as exercise would. The irisin also was shown to improve glucose tolerance in the mice when they were fed a high-fat diet. The mice also lost a small amount of weight within 10 days of the treatment.
So far, the irisin appears to have no side effects. Because the mouse form of the protein is identical to the human form, Dr. Spiegelman suspects that clinical testing could proceed within the next two years. "It's exciting to find a natural substance connected to exercise that has such clear therapeutic potential," added Bostrom.
But, they warn, even should a pill or dietary supplement be developed from irisin, the discovery won’t allow people to skip the gym. “The last thing in the world we’re trying to do is substitute for diet and exercise,” stresses Dr. Spiegelman. For example, the hormone does not appear to make muscles stronger, still an important outcome of daily physical exercise.
The researchers are continuing to explore irisin’s possible health benefits, including potentially even being used in the treatment of Parkinson’s disease because the process appears to have protective effects on mitochondrial metabolism as well. Irisin has been licensed exclusively to Ember Therapeutics, based in Boston, for drug development.
Bostrom P, et al. A PGC1-α-dependent myokine that drives brown-fat-like development of white fat and thermogenesis. Nature (2012) doi:10.1038/nature10777