Featured Research

from universities, journals, and other organizations

How To Get Obese Mice Moving -- And Cure Their Diabetes

Date:
June 2, 2009
Source:
Cell Press
Summary:
Mice lacking the fat hormone leptin or the ability to respond to it become morbidly obese and severely diabetic -- not to mention downright sluggish. Now, a new study shows that blood sugar control in those animals can be completely restored by returning leptin sensitivity to a single class of neurons in the brain, which account for only a small fraction of those that normally carry the hormone receptors.

Mice lacking the fat hormone leptin or the ability to respond to it become morbidly obese and severely diabetic—not to mention downright sluggish. Now, a new study in the June Cell Metabolism shows that blood sugar control in those animals can be completely restored by returning leptin sensitivity to a single class of neurons in the brain, which account for only a small fraction of those that normally carry the hormone receptors.

Related Articles


"Just the receptors in this little group of neurons are sufficient to do the job," said Christian Bjorbaek of Harvard Medical School.

What's more, animals with leptin receptors only in the so-called pro-opiomelanocortin (POMC) neurons spontaneously increase their physical activity levels despite the fact that they remain profoundly obese. While understanding exactly how the POMC neurons act on other organs remains a future challenge, the discovery suggests that drugs designed to tap into the pathway—turning up or down the dial, so to speak—might have benefit for those with severe diabetes and obesity, according to the researchers.

Such drugs might even encourage obese individuals to get moving. "This gives us the opportunity to search for drugs that might induce the desire or will to voluntarily exercise," Bjorbaek said.

Leptin was first identified 15 years ago and made famous for its ability to curb appetite and lead to weight loss. It is known to play a pivotal role in energy balance through its effects on the central nervous system, specifically by acting on a hypothalamic brain region known as the arcuate nucleus (ARC). The ARC contains two types of leptin-responsive neurons, the POMC neurons, which cause a loss of appetite, and the so-called Agouti-related peptide (AgRP) neurons, which do the opposite.

Studies had also revealed a role for leptin in blood sugar control and activity level, also via effects on the ARC. However, scientists still didn't know which neurons were responsible, until now.

When the researchers restored leptin receptor activity in POMC neurons of otherwise leptin-resistant, obese, and diabetic mice, the animals began eating about 30 percent fewer calories and lost a modest amount of weight. Remarkably, the researchers report, their blood sugar levels returned to normal independently of any change in their eating habits or weight. The animals also doubled their activity levels.

Whether this particular bunch of neurons also plays a similarly important role in animals that are lean remains uncertain, Bjorbaek said. "It may be that in the context of severe obesity and diabetes, these neurons do something they don't normally do," he said. But, he added, even if that were the case, it may not matter when it comes to its potential as a therapeutic target.

The researchers include Lihong Huo, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, Kevin Gamber, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, Sarah Greeley, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, Jose Silva, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA; Nicholas Huntoon, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, Xing-Hong Leng, Baylor College of Medicine, Houston, TX; and Christian Bjørbæk, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA.


Story Source:

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


Cite This Page:

Cell Press. "How To Get Obese Mice Moving -- And Cure Their Diabetes." ScienceDaily. ScienceDaily, 2 June 2009. <www.sciencedaily.com/releases/2009/06/090602122617.htm>.
Cell Press. (2009, June 2). How To Get Obese Mice Moving -- And Cure Their Diabetes. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2009/06/090602122617.htm
Cell Press. "How To Get Obese Mice Moving -- And Cure Their Diabetes." ScienceDaily. www.sciencedaily.com/releases/2009/06/090602122617.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Christmas Kissing Good for Health

Christmas Kissing Good for Health

Reuters - Innovations Video Online (Dec. 22, 2014) — Scientists in Amsterdam say couples transfer tens of millions of microbes when they kiss, encouraging healthy exposure to bacteria. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Brain-Dwelling Tapeworm Reveals Genetic Secrets

Brain-Dwelling Tapeworm Reveals Genetic Secrets

Reuters - Innovations Video Online (Dec. 22, 2014) — Cambridge scientists have unravelled the genetic code of a rare tapeworm that lived inside a patient's brain for at least four year. Researchers hope it will present new opportunities to diagnose and treat this invasive parasite. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Americans Drink More in the Winter

Americans Drink More in the Winter

Buzz60 (Dec. 22, 2014) — The BACtrack breathalyzer app analyzed Americans' blood alcohol content and found out a whole lot of interesting things about their drinking habits. Mara Montalbano (@maramontalbano) has more. Video provided by Buzz60
Powered by NewsLook.com
Touch-Free Smart Phone Empowers Mobility-Impaired

Touch-Free Smart Phone Empowers Mobility-Impaired

Reuters - Innovations Video Online (Dec. 21, 2014) — A touch-free phone developed in Israel enables the mobility-impaired to operate smart phones with just a movement of the head. Suzannah Butcher reports. Video provided by Reuters
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