Researchers at the University of California, San Diego report new insights into what nutrients fat cells metabolize to make fatty acids. The findings pave the way for understanding potential irregularities in fat cell metabolism that occur in patients with diabetes and obesity and could lead to new treatments for these conditions. The researchers published their findings online in the Nov. 16 issue of Nature Chemical Biology.
"This study highlights how specific tissues in our bodies use particular nutrients. By understanding fat cell metabolism at the molecular level, we are laying the groundwork for further research to identify better drug targets for treating diabetes and obesity," said Christian Metallo, a bioengineering professor in the Jacobs School of Engineering at UC San Diego and senior author of the study. Metallo is affiliated with the Institute for Engineering in Medicine, the Moore's Cancer Center, and the CHO Systems Biology Center, all at UC San Diego.
Microscopy image depicting fat cells (or adipocytes) after differentiation. The cells are stained with Oil Red O, which highlights lipid or fat droplets that accumulate with the fat cells. The metabolic studies described here indicated that fat cells produce these fatty acids, in part, from essential amino acids rather than sugar only.
Credit: Metabolic Systems Biology lab, UC San Diego Jacobs School of Engineering
In the new study, researchers discovered that as fat cells develop, they change what types of nutrients they metabolize to produce fat and energy. Pre-adipocytes, which are precursors to fat cells, preferentially consume glucose, a simple sugar, to grow and make energy. But when pre-adipocytes become fat cells, researchers found that they metabolize not just glucose, but also branched-chain amino acids, a small set of the essential amino acids for humans.
This finding is important because it shows that fat cells play an important role in regulating the body's levels of branched-chain amino acids -- which are typically elevated in individuals with diabetes and obesity.
"We've taken a step towards understanding why these amino acids are accumulating in the blood of diabetics and those suffering from obesity," said Courtney Green, a bioengineering Ph.D. student at UC San Diego and first author of the study. "The next step is to understand how and why this metabolic pathway becomes impaired in the fat cells of these individuals."
Metallo and his team studied the metabolism of fat cells from the pre-adipocyte stage throughout the fat cell differentiation process. They induced pre-adipocytes to differentiate into fat cells and cultured the cells in media containing nutrients enriched with carbon-13 isotopes, a form of carbon atoms that are used as metabolic tracers in cells, animals, and people. Through this method, researchers were able to trace what carbon-based nutrients the cells metabolized and what they produced at different stages of the cell differentiation process.
"We are curious about how different cells in our body, such as fat cells, consume and metabolize their surrounding nutrients. A better understanding of how these biochemical pathways are used by cells could help us find new approaches to treat diseases such as cancer or diabetes," said Metallo.
This work was supported by the National Institutes of Health, the California Institute of Regenerative Medicine, the US Department of Defense, a Searle Scholar Award, and grants from the American Diabetes Association, the Medical Research Service, the US Department of Veterans Affairs and the VA San Diego Healthcare System, and Seahorse Bioscience.
Full paper: "Branched-chain amino acid catabolism fuels adipocyte differentiation and lipogenesis" by Courtney R. Green, Martina Wallace, Ajit S. Divakaruni, Susan A. Philips, Anne M. Murphy, Theodore P. Ciaraldi, and Christian M. Metallo. The paper was published online in the Nov. 16, 2015 issue of the journal Nature Chemical Biology.
Liezel Labios | EurekAlert!
Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care
Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses