Featured Research

from universities, journals, and other organizations

Fat-free Diet Reduces Liver Fat In Fat-free Mice, Researchers Report

Date:
February 13, 2009
Source:
UT Southwestern Medical Center
Summary:
Researchers have uncovered crucial clues about a paradoxical disease in which patients with no body fat develop many of the health complications usually found in obese people.

Researchers at UT Southwestern Medical Center have uncovered crucial clues about a paradoxical disease in which patients with no body fat develop many of the health complications usually found in obese people.

The findings in mice, appearing online Feb 3 in Cell Metabolism, have led to the initiation of a National Institutes of Health-funded clinical trial to determine whether eating an extremely low-fat diet could prevent many of the metabolic complications brought on by lipodystrophy.

Lipodystrophies are metabolic disorders characterized by the selective loss of fat tissues and complications of insulin resistance. Scientists speculate that the condition could be caused by the failure of stem cells to become fat cells.

"These patients don't have fatty tissue, even inside their abdomen," said Dr. Abhimanyu Garg, professor of internal medicine at UT Southwestern and senior author of the study. "They basically lack all the fat we see in a typical person, but their livers are loaded with fat. That's a big problem because too much fat in the liver leads to liver damage.

"We cannot do anything to reverse fat loss, but our findings might lead to the development of new therapies for the metabolic complications of lipodystrophy, such as diabetes, fatty liver and high triglycerides," said Dr. Garg, an investigator in the Center for Human Nutrition.

Dr. Garg has been studying patients with lipodystrophies for more than 20 years. He and colleagues at UT Southwestern have led the way in identifying gene mutations responsible for several forms of lipodystrophy and in identifying novel therapeutic approaches for these patients.

In this study, researchers genetically engineered mice to lack a specific enzyme called AGPAT2, which is also lacking in humans with generalized lipodystrophy. Under normal conditions, AGPAT2 is involved in the production of fat in body fat cells. In 2002 Dr. Garg's lab found that the AGPAT2 gene is mutated in patients with congenital generalized lipodystrophy.

"We generated this mouse model to learn why humans with this type of lipodystrophy develop metabolic complications," Dr. Garg said.

The researchers found that mice without the AGPAT2 enzyme used a novel, previously uncharacterized pathway to synthesize fat in their liver. Dietary fat also contributed to fat accumulation in the liver. Typically, particles called chylomicrons carry dietary fat throughout the body and release it in peripheral tissues so that it can either be stored in adipose tissue for later use or immediately burned as energy by muscles. Normally, adipose tissue provides fatty acids for fat synthesis in the liver. In these lipodystrophic mice, however, the adipose tissue did not release the excess fatty acids and the dietary fat accumulated in the liver.

What is surprising about this, Dr. Garg said, is that the amount of fat stored in the liver dropped substantially when researchers put the lipodystrophic mice on a fat-free diet. "Just eliminating the dietary fat reduced liver triglycerides by approximately 50 percent," he said.

In addition to establishing a clinical trial, Dr. Garg said the next step is to study the stem cells from the mice with lipodystrophy in order to determine why their stem cells become bone and muscle but not fat.

Other UT Southwestern researchers involved in the research were Dr. Victor Cort้s, lead author of the study and postdoctoral researcher in molecular genetics; Dr. David Curtis, surgery resident; Dr. Xinli Shao, research scientist in immunology; Dr. Vinay Parameswara, instructor of internal medicine; Dr. Jimin Ren, instructor in radiology at the Advanced Imaging Research Center; Dr. Victoria Esser, associate professor of internal medicine; Dr. Robert Hammer, professor of biochemistry; Dr. Anil Agarwal, associate professor of internal medicine; and Dr. Jay Horton, professor of internal medicine.

The research was funded by the NIH, Southwestern Medical Foundation and the Perot Foundation. Dr. Cort้s is supported by a postdoctoral fellowship from Pontificia Universidad Cat๓lica de Chile and a presidential fellowship from the Chilean government.

 


Story Source:

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


Cite This Page:

UT Southwestern Medical Center. "Fat-free Diet Reduces Liver Fat In Fat-free Mice, Researchers Report." ScienceDaily. ScienceDaily, 13 February 2009. <www.sciencedaily.com/releases/2009/02/090203120718.htm>.
UT Southwestern Medical Center. (2009, February 13). Fat-free Diet Reduces Liver Fat In Fat-free Mice, Researchers Report. ScienceDaily. Retrieved April 20, 2014 from www.sciencedaily.com/releases/2009/02/090203120718.htm
UT Southwestern Medical Center. "Fat-free Diet Reduces Liver Fat In Fat-free Mice, Researchers Report." ScienceDaily. www.sciencedaily.com/releases/2009/02/090203120718.htm (accessed April 20, 2014).

Share This



More Health & Medicine News

Sunday, April 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nine-Month-Old Baby Can't Open His Mouth

Nine-Month-Old Baby Can't Open His Mouth

Newsy (Apr. 19, 2014) — Nine-month-old Wyatt Scott was born with a rare disorder called congenital trismus, which prevents him from opening his mouth. Video provided by Newsy
Powered by NewsLook.com
'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) — In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) — A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) — The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
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:
from the past week

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