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
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences