Researchers Discover New Hormone That Affects Fat and Glycogen Storage in Liver and Muscle
A scientist at the Maine Medical Center Research Institute has discovered a hormone that could lead to new treatments targeting excessive fat, as well as glycogen storage in the liver and muscles.
A research team led by Volkhard Lindner, MD, PhD, discovered that the absence of this hormone - Collagen Triple Helix Repeat Containing-1 (Cthrc1) - causes fatty liver formation in mice while also increasing glycogen in muscle. Too much fat in the liver can be toxic, and its presence has been linked to diabetes- and obesity-related morbidity, in addition to a host of other diseases.
Glucose is stored in liver and muscle cells in the form of glycogen. Muscles rely on its availability to perform muscle work. For example, the amount of glycogen stored plays a critical role on how long muscles can perform high-intensity exercise - such as sprinting or weightlifting - before exhaustion, although looking at factors that can regulate glycogen storage in muscle will be relevant to any athletic activity.
Dr. Lindner, originally discovered this hormone, Collagen Triple Helix Repeat Containing-1 (Cthrc1), in injured blood vessels and developed a strain of mice without this gene to determine its impact on organs and tissues.
Interestingly, the Cthrc1 protein was not detectable in the liver or muscles of normal mice. The sources of the protein, the researchers realized, were the pituitary gland, the hypothalamus in the brain, as well as bone cells, all of which are part of the endocrine system.
The link to the endocrine system led Lindner and his team to the surprising conclusion that a new circulating hormone was sending signals to the liver and muscle. The investigators were able to demonstrate the presence of this hormone in human blood samples.
Several decades have passed since the discovery of a new pituitary hormone. "Our findings of this new hormone will have a substantial impact on how we think about conditions such as diabetes, obesity, and glycogen storage diseases," says Lindner.
The results of this study are published online in PLOS ONE an online, peer-reviewed medical journal.
John Lamb, APR
Maine Medical Center