Navigation Links
Enzyme boosts metabolism, prevents weight gain in mice
Date:11/14/2011

PROVIDENCE, R.I. [Brown University] In a new study, scientists report that they substantially curbed weight gain, improved metabolism, and improved the efficacy of insulin in mice by engineering them to express a specific human enzyme in their fat tissue. Although the obesity prevention came at the significant cost of widespread inflammation, the research offers new clues about the connections among obesity, insulin resistance and type 2 diabetes, and inflammation.

"Turning on this molecule has a very dramatic impact on lipid metabolism," said Haiyan Xu, assistant professor of medicine (research) in the Warren Alpert Medical School of Brown University and a researcher at Rhode Island Hospital's Hallett Center for Diabetes and Endocrinology. Xu is the corresponding author of a paper describing the research in the January 2012 issue of Endocrinology and released early online.

The relationship between fat, inflammation, and insulin performance is complex. The conventional wisdom is that obesity leads to inflammation which contributes to insulin resistance. In this study, the researchers changed the sequence of events for transgenically engineered mice by inducing inflammation via the enzyme IKKbeta in their fatty tissue before they were obese. The result for metabolism was much more positive than for control mice who were left unaltered but were fed the same diets.

For both male and female mice, the ones who were altered still put on weight but significantly more slowly. All the mice started at the same weight. After about 22 weeks on a high-fat diet, however, altered male mice weighed less than 38 grams while unaltered male mice weighed more than 45 grams. On a less extravagant diet named "chow" the difference was considerably lessened but was still statistically significant. Both trends held for females as well.

The altered mice experienced slower weight gain despite eating much more food. Their increased metabolism allowed them to dispatch the extra calories much more efficiently. After being injected with glucose, for example, altered mice maintained lower blood sugar levels than unaltered mice. The same was true after insulin injections, suggesting that insulin was more effective. In addition, the transgenic mice expended much more energy than their normal counterparts, suggesting that the sugar was indeed metabolized.

The mechanisms by which IKKbeta in fatty tissue increases metabolic performance are not completely clear, but the researchers measured increased expression of genes associated both with fatty acid oxidation and with making mitochondria, a cell part responsible for producing energy.

One possible lesson from the research seems to be that while obesity and inflammation are both promoters of insulin resistance, Xu said, obesity seems to be the worse one.

"Lower body weight is always a beneficial thing for influencing insulin sensitivity," she said. "Reduced adiposity wins over increased inflammation."

Another point is that IKKbeta's ability to aid metabolism may be specific to its activation in fat tissue. In previous studies, scientists had activated it in the liver with no weight-reduction benefits and in the brain's hypothalamus, leading to increased weight gain.


'/>"/>

Contact: David Orenstein
david_orenstein@brown.edu
401-863-1862
Brown University
Source:Eurekalert

Related biology news :

1. Atomic-resolution views suggest function of enzyme that regulates light-detecting signals in eye
2. New insight into the controls on a go-to enzyme
3. UNC scientists teach enzyme to make synthetic heparin in more varieties
4. Rare disease provides clues about enzyme role in arrhythmias
5. Brain enzyme may play key role in controlling appetite and weight gain
6. Newly found enzymes may play early role in cancer
7. HWI scientist first in world to unravel structure of key breast cancer target enzyme
8. Researchers first to see reactive oxygen species in vital enzyme
9. Disabling enzyme allows mice to gorge without becoming obese, new study finds
10. Structure of enzyme against chemical warfare agents determined
11. Researchers find pathway and enzyme unique to tularemia organism
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/14/2016)... http://www.apimages.com ) - ... - Renvoi : image disponible via AP Images ( ... --> DERMALOG, le leader de l,innovation ... d,empreintes digitales pour l,enregistrement des réfugiés en Allemagne. ... produire des cartes d,identité aux réfugiés. DERMALOG dévoilera ...
(Date:3/10/2016)... Pa. , March 10, 2016   Unisys Corporation ... Customs and Border Protection (CBP) is testing its biometric ... San Diego to help identify certain non-U.S. ... . The test, designed to help determine the efficiency ... environment, began in February and will run until May 2016. ...
(Date:3/8/2016)... 8, 2016   Valencell , the leading ... it has secured $11M in Series D financing. ... new venture fund being launched by UAE-based financial ... existing investors TDF Ventures and WSJ Joshua Fund. ... its triple-digit growth and accelerate its pioneering innovation ...
Breaking Biology News(10 mins):
(Date:5/17/2016)... ... May 17, 2016 , ... DryLet, ... reduction applications, announced today it will be showcasing ManureMagic™ at booth V1061 at ... featured in the Wall Street Journal last year and more recently made news ...
(Date:5/17/2016)... ... May 17, 2016 , ... PATH ... they will collaborate to bring a feeding cup to market based on a ... the Craniofacial Center at Seattle Children’s Hospital, thereby ensuring an innovative feeding option ...
(Date:5/17/2016)... Strekin AG, a start-up ... Switzerland announced today the in-licensing of ... protein kinase.      (Logo: http://photos.prnewswire.com/prnh/20160513/367502LOGO ... the necessary research foundation for the clinical development ... play fundamental roles. Pamapimod has a well-established safety ...
(Date:5/17/2016)... ... 17, 2016 , ... Yukon Medical, a leading developer of ... and Company) to receive its Global Product Innovation Supplier of the Year Award. ... contributions to advancing or supporting key BD initiatives, products, processes, and customer satisfaction. ...
Breaking Biology Technology: