In a recent study in mice, researchers at Johns Hopkins pinpointed an enzyme that keeps neurons’ fat levels under control, and may be implicated in human neurological diseases. Their findings are published in the May 2013 issue of Molecular and Cellular Biology.
“There are known connections between problems with how the body’s cells process fats and neurodegenerative diseases such as Alzheimer’s, Parkinson’s and amyotrophic lateral sclerosis,” says Michael Wolfgang, Ph.D., an assistant professor in the Department of Biological Chemistry at the Johns Hopkins University School of Medicine’s Institute for Basic Biomedical Sciences. “Now we’ve taken a step toward better understanding that connection by identifying an enzyme that lets neurons get rid of excess fat that would otherwise be toxic.”
Wolfgang says one clue to the reason for the neurodegeneration/fat-processing connection is that neurons, unlike most cells in the body, seemingly can’t break down fats for energy. Instead, brain cells use fats for tasks such as building cell membranes and communicating information. At the same time, he says, they must prevent the buildup of unneeded fats. Neurons’ fat-loss strategy is rooted in the fact that a fat molecule attached to a chemical group called coenzyme A will be trapped inside the cell, while the coenzyme A-free version can easily cross the cell membrane and escape. With this in mind, Wolfgang, along with colleagues Jessica Ellis, Ph.D., and G. William Wong, Ph.D., focused their study on an enzyme, called ACOT7, which is plentiful in the brain and lops coenzyme A off of certain fat molecules.
The team created mice with a non-working gene for ACOT7 and compared them with normal mice. The scientists saw no obvious differences between the two types of mice as long as they had ready access to food, Wolfgang says. But when food was taken away overnight, so that the mice’s cells would start to break down their fat stores and release fat molecules into the bloodstream for use as energy, ACOT7’s role began to emerge. While the normal fasting mice were merely hungry, the mice lacking ACOT7 had poor coordination, a sign of neurodegeneration. More differences emerged when the researchers dissected the mice; most strikingly, the livers of mice missing ACOT7 were “stark white” with excess fat, Wolfgang says.
Wolfgang cautions that his group’s results are not quite a smoking gun for ACOT7’s involvement in human neurological disease, but says they add to existing circumstantial evidence pointing in that direction. He notes that a special diet that changes the levels of fats and sugars in the bloodstream – the so-called ketogenic diet – can prevent seizures in epileptics; in addition, one study found that patients with epilepsy have less of the ACOT7 enzyme than healthy people.
“We think ACOT7’s purpose is to protect neurons from toxicity and death by allowing excess fat to escape the cells,” Ellis says. “Our next step will be to see whether this enzyme does indeed play a role in human neurological disease.”
Link to the paper: http://mcb.asm.org/content/33/9/1869.full
The study was funded by the American Heart Association (grant numbers SDG2310008 and SDG2260721), the National Institute of Neurological Disorders and Stroke (grant number NS072241), the National Institute of Diabetes and Digestive and Kidney Diseases (grant number DK084171) and the Baltimore Diabetes Research and Training Center (grant number P60DK079637).
Shawna Williams | Newswise
A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
On the way to developing a new active ingredient against chronic infections
21.08.2017 | Deutsches Zentrum für Infektionsforschung
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
21.08.2017 | Materials Sciences
21.08.2017 | Health and Medicine
21.08.2017 | Materials Sciences