Featured Research

from universities, journals, and other organizations

Hormone linked to calorie-burning brown fat

Date:
January 9, 2014
Source:
Joslin Diabetes Center
Summary:
Researchers have discovered that a hormone long associated with weight loss and improved glucose metabolism is linked to activation of calorie-burning brown fat.

Researchers at Joslin Diabetes Center have discovered that a hormone long associated with weight loss and improved glucose metabolism is linked to activation of calorie-burning brown fat. This finding could have implications for production of new medications for type 2 diabetes and obesity. The results are published in the January issue of The Journal of Clinical Investigation in a paper titled "Interplay between FGF21 and Insulin Action in the Liver for the Regulation of Metabolism."

Related Articles


For the past decade, FGF21 has been known to play a role in metabolic regulation. Its mechanism of action, however, remained unidentified.

"So what we were interested in learning is how does FGF21 stimulate both weight loss and improve glucose metabolism," said C. Ronald Kahn, M.D., Chief Academic Officer at Joslin Diabetes Center, Mary K. Iacocca Professor of Medicine at Harvard Medical School, and the corresponding author on the paper. "And this study shows that one big factor in this is the ability of FGF21 to stimulate what's called browning of white fat, that is where the white fat becomes more energetically active and begins to burn energy rather than store energy."

Brown fat, shown to exist in humans in 2009 by researchers at Joslin, burns calories to produce heat. White fat can act in a similar manner when stimulated, a process known as "browning." Determining stimulation mechanisms can provide researchers with a first step towards using brown fat as a treatment for obesity and type 2 diabetes.

FGF21 is secreted from the liver, prompting the researchers to question if its metabolic-related activity depended on molecular interactions within the liver tissues. They tested this using insulin resistant animal models created through two different methods -- in one model, they created obesity-induced insulin resistance through a high fat diet; in the other, they knocked out the insulin signaling in liver tissues.

They then introduced FGF21 to the system continuously for two weeks via an inserted pump. During that time, they monitored weight, blood glucose levels, and lipid levels. After the two weeks ended, they harvested liver tissues to analyze their makeup.

"What we found was that even without insulin signaling in the liver, FGF21 could still improve glucose metabolism," said Dr. Kahn. To determine that the improvements were due to the browning of white fat, rather than the activation of brown fat, they surgically removed the pads of brown fat found in the animals, so that any fat-based energy burning would surely have to be a result of white fat browning.

"So in those animals, where most of the brown fat is removed, FGF 21 still works on the remaining white fat because of browning," he said.

FGF21 also regulates lipid metabolism, and that function was determined to be dependent on functioning insulin signaling in the liver.

Proving that FGF21 activates the browning of white fat is a large step forward in understanding the process of how variations of brown fat assist in metabolic regulation. Identifying this hormone as a major player in this activation has implications for the eventual creation of a brown fat stimulating drug.

"As with any new drug or hormone, of course we need to learn not only its good effects, but also any potential side effects," said Dr. Kahn. "And I think that's where a lot of the effort is now…by pharmaceutical companies."

Drug creation aside, Dr. Kahn thinks this discovery is interesting from a basic biology point of view.

"FGF 21 wasn't even known to exist until 10 years ago, and now we know it is a new circulating hormone, that is regulated in feeding and fasting," he said. "And I think that this is another piece of evidence that we don't understand all there is to know yet about metabolic regulation even though people have been studying it for literally hundreds of years."


Story Source:

The above story is based on materials provided by Joslin Diabetes Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Brice Emanuelli, Sara G. Vienberg, Graham Smyth, Christine Cheng, Kristin I. Stanford, Manimozhiyan Arumugam, Mervyn D. Michael, Andrew C. Adams, Alexei Kharitonenkov, C. Ronald Kahn. Interplay between FGF21 and insulin action in the liver regulates metabolism. Journal of Clinical Investigation, 2014; DOI: 10.1172/JCI67353

Cite This Page:

Joslin Diabetes Center. "Hormone linked to calorie-burning brown fat." ScienceDaily. ScienceDaily, 9 January 2014. <www.sciencedaily.com/releases/2014/01/140109132136.htm>.
Joslin Diabetes Center. (2014, January 9). Hormone linked to calorie-burning brown fat. ScienceDaily. Retrieved March 31, 2015 from www.sciencedaily.com/releases/2014/01/140109132136.htm
Joslin Diabetes Center. "Hormone linked to calorie-burning brown fat." ScienceDaily. www.sciencedaily.com/releases/2014/01/140109132136.htm (accessed March 31, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Tuesday, March 31, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Solitair Device Aims to Takes Guesswork out of Sun Safety

Solitair Device Aims to Takes Guesswork out of Sun Safety

Reuters - Innovations Video Online (Mar. 31, 2015) — The Solitair device aims to take the confusion out of how much sunlight we should expose our skin to. Small enough to be worn as a tie or hair clip, it monitors the user&apos;s sun exposure by taking into account their skin pigment, location and schedule. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Soda, Salt and Sugar: The Next Generation of Taxes

Soda, Salt and Sugar: The Next Generation of Taxes

Washington Post (Mar. 30, 2015) — Denisa Livingston, a health advocate for the Dinι Community Advocacy Alliance, and the Post&apos;s Abby Phillip discuss efforts around the country to make unhealthy food choices hurt your wallet as much as your waistline. Video provided by Washington Post
Powered by NewsLook.com
UnitedHealth Buys Catamaran

UnitedHealth Buys Catamaran

Reuters - Business Video Online (Mar. 30, 2015) — The $12.8 billion merger will combine the U.S.&apos; third and fourth largest pharmacy benefit managers. Analysts say smaller PBMs could also merge. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
S. Leone in New Anti-Ebola Lockdown

S. Leone in New Anti-Ebola Lockdown

AFP (Mar. 28, 2015) — Sierra Leone imposed a three-day nationwide lockdown Friday for the second time in six months in a bid to prevent a resurgence of the deadly Ebola virus. Duration: 01:17 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins