Featured Research

from universities, journals, and other organizations

How Stressed Fat Tissue Malfunctions

Date:
July 22, 2009
Source:
American Associates, Ben-Gurion University of the Negev
Summary:
Fat tissue dysfunction is caused by obesity-induced fat tissue stress: Cells over-grow as they store fat which may cause decreased oxygen delivery into the tissue; individual cells may die (at least in mouse models), and fat tissue inflammation ensues. The teams collected fat tissue samples from people undergoing abdominal surgery and identified a signaling pathway that is operational in intra-abdominal fat, the fat depot that is most strongly tied to obesity-related morbidity.

Ben-Gurion University of the Negev (BGU) researchers, in a collaboration with colleagues from the University of Leipzig, Germany, have identified a signaling pathway that is operational in intra-abdominal fat, the fat depot that is most strongly tied to obesity-related morbidity.

Related Articles


The paper was just published in the Endocrine Society's the Journal of Clinical Endocrinology and Metabolism.

"Fat tissue in obesity is dysfunctional, yet, the processes that cause fat tissue to malfunction are poorly understood -- specifically, it is unknown how fat cells 'translate' stresses in obesity into dysfunction," said Dr. Assaf Rudich, senior lecturer from the Department of Clinical Biochemistry at Ben-Gurion University.

Fat tissue is no longer considered simply a storage place for excess calories, but in fact is an active tissue that secretes multiple compounds, thereby communicating with other tissues, including the liver, muscles, pancreas and the brain. Normal communication is necessary for optimal metabolism and weight regulation. However, in obesity, fat (adipose) tissue becomes dysfunctional, and mis-communicates with the other tissues. This places fat tissue at a central junction in mechanisms leading to common diseases attributed to obesity, like type 2 diabetes and cardiovascular diseases.

Fat tissue dysfunction is believed to be caused by obesity-induced fat tissue stress: Cells over-grow as they store increasing amounts of fat. This excessive cell growth may cause decreased oxygen delivery into the tissue; individual cells may die (at least in mouse models), and fat tissue inflammation ensues. Also, excess nutrients (glucose, fatty acids) can also result in increased metabolic demands, and this in itself can cause cellular stress.

The BGU and Leipzig teams established a setup for collecting fat tissue samples from people undergoing abdominal surgery. The team identified a signaling pathway that is operational in intra-abdominal fat, the fat depot that is most strongly tied to obesity-related morbidity.

The degree of activation of a signaling pathway from these individuals was compared with those of leaner people, those with obesity predominantly characterized by accumulation of "peripheral" fat, and those with obesity with predominant accumulation of fat within the abdominal cavity.

They discovered that the signaling pathway was more active depending on the amount of fat accumulation in the abdomen, and that it correlated with multiple biochemical markers for increased cardio-metabolic risk. Moreover, the expression of one of the upstream signaling components, a protein called ASK1, predicts whole-body insulin resistance (an endocrine abnormality that is strongly tied to diabetes and cardiovascular disease), independent of other traditional risk factors.

Researchers also demonstrated that although non-fat cells within adipose tissue express most of this protein in lean persons, the adipocytes themselves increase its expression by more than four-fold in abdominally-obese persons.

"The importance of this study is not only in contributing to the understanding of adipose tissue dysfunction in obesity, but as a consequence, may provide important leads for novel ways to prevent the dangerous consequences, such as type 2 diabetes, of intra-abdominal fat accumulation," states Dr. Iris Shai, a BGU researcher at the S. Daniel Abraham International Center for Health and Nutrition and Soroka University Medical Center in Beer-Sheva, Israel.

* J. Clin. Endocrinol. Metab. 2009; 94:2507-251.

The project was initially established by a grant from BGU's National Institute for Biotechnology in the Negev (NIBN). Then by grants from The Israeli Association for the Study of Diabetes, D-Cure, The Israel Science Foundation (ISF), and Deutsche Forschungsgemeinschaft (DFG).


Story Source:

The above story is based on materials provided by American Associates, Ben-Gurion University of the Negev. Note: Materials may be edited for content and length.


Journal Reference:

  1. Bluher et al. Activated Ask1-MKK4-p38MAPK/JNK Stress Signaling Pathway in Human Omental Fat Tissue May Link Macrophage Infiltration to Whole-Body Insulin Sensitivity. Journal of Clinical Endocrinology & Metabolism, 2009; 94 (7): 2507 DOI: 10.1210/jc.2009-0002

Cite This Page:

American Associates, Ben-Gurion University of the Negev. "How Stressed Fat Tissue Malfunctions." ScienceDaily. ScienceDaily, 22 July 2009. <www.sciencedaily.com/releases/2009/07/090714125002.htm>.
American Associates, Ben-Gurion University of the Negev. (2009, July 22). How Stressed Fat Tissue Malfunctions. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2009/07/090714125002.htm
American Associates, Ben-Gurion University of the Negev. "How Stressed Fat Tissue Malfunctions." ScienceDaily. www.sciencedaily.com/releases/2009/07/090714125002.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Rural India's Low-Cost Sanitary Pad Revolution

Rural India's Low-Cost Sanitary Pad Revolution

AFP (Nov. 28, 2014) — One man hopes his invention -– a machine that produces cheap sanitary pads –- will help empower Indian women. Duration: 01:51 Video provided by AFP
Powered by NewsLook.com
Research on Bats Could Help Develop Drugs Against Ebola

Research on Bats Could Help Develop Drugs Against Ebola

AFP (Nov. 28, 2014) — In Africa's only biosafety level 4 laboratory, scientists have been carrying out experiments on bats to understand how virus like Ebola are being transmitted, and how some of them resist to it. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
Experimental Ebola Vaccine Shows Promise In Human Trial

Experimental Ebola Vaccine Shows Promise In Human Trial

Newsy (Nov. 27, 2014) — A recent test of a prototype Ebola vaccine generated an immune response to the disease in subjects. 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:

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