Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Obesity Chokes up the Cellular Power Plant

12.03.2008
Obesity associated with clear changes in gene-networks and dysfunction of mitochondria

The machinery responsible for energy production in fat cells is working poorly as a result of obesity. Finnish research done at the University of Helsinki and the National Public Health Institute shows that this may aggravate and work to maintain the obese state in humans.

Studying rare cases of young (25 year old) identical twins with large differences in bodyweight a Finnish research group has shown that already in the very early stages of obesity, clear changes in the function of the cellular mitochondria can be observed. Mitochondria are responsible for the energy production in cells and their dysfunction may work to maintain and worsen obesity. Surprisingly, the genes most drastically affected by obesity were ones involved in the breakdown of a class of amino acids known as branched-chain amino acids. These changes in the obese twins were clearly associated with pre-diabetic changes in sugar metabolism and the action of the hormone insulin.

The research is published in the latest edition of the science journal PLoS-Medicine (published and freely available online 11th of March).

Along with all its associated ailments, obesity is an ever increasing health concern. While healthy eating habits and exercise are important, genes do play their own important part in the development of obesity.

“Identical twins share all the same genes and almost always are also identical in weight. Studying identical twins that do differ in weight is the best approach we have to get at the mechanisms involved in the interplay between genes and environment that result in obesity”, explains research scientist Kirsi Pietiläinen from the department of Public Health at the University of Helsinki, Finland. In a large collection of 650 pairs of Finnish twins born between the years 1975 and 1979, the researchers were able to identify only 18 pairs that at the age of 25 had developed more than a 10 kg (22 lb) difference in weight. The body composition and metabolism of 14 of these pairs was carefully studied and a sample of their fat was also obtained.

In a case where one of the identical twins is considerably heavier than the other, the reason behind this is not in the genes. Regardless of their identical genes, these genes can however be active at a different level. The research took advantage of this condition in order to characterize those changes in gene activity in fat tissue that result from obesity.

The researchers identified that the fat cells of the obese twins contained fewer copies of the DNA located in mitochondria. This DNA contains the instructions for energy use by the cell. “If one were to compare this cellular power plant with a car engine, it could be said that the engine of the fat individual is less efficient”, Pietiläinen says. An inefficient mitochondrial engine can also put out toxic exhaust. A clear sign of inflammation was observed in the obese twins’ fat tissue –a sign of the poor health of the cells.

Another sign of dysfunction in the mitochondria was also the much decreased breakdown of these branched-chain amino acids. What makes this observation especially important is the fact that the decreased breakdown of these amino acids, and their resultant increased concentration in the blood, was directly associated with pre-diabetic changes, fattening of the liver and the excessive release of insulin by the pancreas.

The research employed a gene-chip technology that enabled the scientists to measure the activity of all human genes. “By employing a genomewide method, biostatistics and the unique set-up of these identical twins, we were able to uncover new mechanisms behind obesity and the early diabetic changes in the metabolism of the fat twins. In the future it will be important to determine whether these changes can be reversed by losing weight”, concludes Jussi Naukkarinen, a scientist at the department of Molecular Medicine, National Public Health Institute of Finland.

Paivi Lehtinen | alfa
Further information:
http://www.helsinki.fi

Further reports about: HDL-cholesterol amino amino acids associated mitochondria obese

More articles from Life Sciences:

nachricht Brought to light – chromobodies reveal changes in endogenous protein concentration in living cells
21.09.2018 | NMI Naturwissenschaftliches und Medizinisches Institut an der Universität Tübingen

nachricht A one-way street for salt
21.09.2018 | Julius-Maximilians-Universität Würzburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists present new observations to understand the phase transition in quantum chromodynamics

The building blocks of matter in our universe were formed in the first 10 microseconds of its existence, according to the currently accepted scientific picture. After the Big Bang about 13.7 billion years ago, matter consisted mainly of quarks and gluons, two types of elementary particles whose interactions are governed by quantum chromodynamics (QCD), the theory of strong interaction. In the early universe, these particles moved (nearly) freely in a quark-gluon plasma.

This is a joint press release of University Muenster and Heidelberg as well as the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt.

Then, in a phase transition, they combined and formed hadrons, among them the building blocks of atomic nuclei, protons and neutrons. In the current issue of...

Im Focus: Patented nanostructure for solar cells: Rough optics, smooth surface

Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.

"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...

Im Focus: New soft coral species discovered in Panama

A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.

Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...

Im Focus: New devices based on rust could reduce excess heat in computers

Physicists explore long-distance information transmission in antiferromagnetic iron oxide

Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.

Im Focus: Finding Nemo's genes

An international team of researchers has mapped Nemo's genome

An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

One of the world’s most prominent strategic forums for global health held in Berlin in October 2018

03.09.2018 | Event News

4th Intelligent Materials - European Symposium on Intelligent Materials

27.08.2018 | Event News

 
Latest News

Three NASA missions return first-light data

24.09.2018 | Physics and Astronomy

Brown researchers teach computers to see optical illusions

24.09.2018 | Information Technology

Astrophysicists measure precise rotation pattern of sun-like stars for the first time

21.09.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>