Nav: Home

Disrupted fat breakdown in the brain makes mice dumb

May 19, 2017

A study led by the University of Bonn opens a new perspective with regard to the development of dementia. The scientists blocked the breakdown of a certain fat molecule in the mouse brain. As a result the animals exhibited learning and memory problems. Also the quantity of Alzheimer-specific proteins in their brains increased significantly. The researchers now have a clue as to why the mice become dumb. The results are published in the renowned scientific journal "Autophagy".

Apart from water, our brain is rich in lipids -- in plain language: fats. The lipids act, for instance, as an insulating layer around the nerve fibers and thus prevent short circuits. However, they are also a main component in the delicate membranes that surround the brain cells.

Sphingolipids, a special lipid type are highly enriched in the brain. One of their degradation products, S1P, may play a central role in the development of Alzheimer's and other forms of dementia. "We raised mice that are no longer able to break down S1P in large parts of their brain," explains Dr. Gerhild van Echten-Deckert. "The animals then displayed severely reduced learning and memory performance."

Van Echten-Deckert undertakes research at the LIMES Institute at the University of Bonn (the acronym stands for "Life and Medical Sciences") as an assistant professor. For a long time, she has been one of the few experts in the world interested in the role of S1P in the brain. The new study could fundamentally change this, as the researchers at the University of Bonn, Jena University Hospital, the German Center for Neurodegenerative Diseases (DZNE) and from San Francisco and Madrid were able to show what far-reaching consequences disrupted S1P breakdown has.

"Self-eating" keeps the brain healthy

Normally, S1P is broken down into simpler products. One such breakdown product generated is important for a vital metabolic pathway - called autophagy. The word autophagy (literally translates to "self-eating") and the pathway enables cells to digest and recycle their own components. The cells are thus cleared from defective proteins and cell organelles that no longer function properly.

Intracellular waste disposal works in two steps: first, it packs the waste in tiny "garbage bags". These then merge with other "bags" that contain highly reactive enzymes. The enzymes "shred" the content of the garbage bags and thus dispose it off.

The break-down product of S1P is involved in packing the waste into the intracellular garbage bags. "If S1P is not broken down, fewer closed garbage bags are formed; autophagy then no longer works accurately," explains the first author of the study Daniel Mitroi, who has recently completed his PhD at the LIMES Institute. "Harmful substances thus accumulated in the brains of our mice. These included the protein APP, which plays a key role in the development of Alzheimer's."

As autophagy is crucial for normal functioning of the brain, improper intracellular waste disposal results in severe illnesses. Therefore last year the Nobel Prize in Medicine was awarded to the Japanese scientist Yoshinori Ohsumi for his notable work on this vital mechanism. The results of the current study shed light on a previously overlooked mechanism for dementia development. "In the long term, our work may contribute towards developing successful treatment strategies for brain disorders," hopes Dr. van Echten-Deckert.
-end-
Publication: Daniel N. Mitroi, Indulekha Karunakaran, Markus Gräler, Julie D. Saba, Dan Ehninger, María Dolores Ledesma and Gerhild van Echten-Deckert: SGPL1 (sphingosine phosphate lyase 1) modulates neuronal autophagy via phosphatidylethanolamine production; Autophagy; DOI: 10.1080/15548627.2017.1291471

Contact:

Dr. Gerhild van Echten-Deckert
LIMES Institute
University of Bonn
Tel. +49 (0)228/732703
E-mail: g.echten.deckert@uni-bonn.de

University of Bonn

Related Dementia Articles:

Flies the key to studying the causes of dementia
A research team from the University of Plymouth, University of Southampton and the Alexander Fleming Biomedical Sciences Research Center, Vari, Greece, have studied two structurally-similar proteins in the adult brain and have found that they play distinct roles in the development of dementia.
Stroke prevention may also reduce dementia
Ontario's stroke prevention strategy appears to have had an unexpected, beneficial side effect: a reduction also in the incidence of dementia among older seniors.
Dementia: The right to rehabilitation
Rehabilitation is important for people with dementia as it is for people with physical disabilities, according to a leading dementia expert.
One in 4 elderly Australian women have dementia
At least a quarter of Australian women over 70 will develop dementia according to University of Queensland researchers.
Rural dementia -- we need to talk
Research carried out by Plymouth University into the experience of dementia in farming and farming families, and its impact on their businesses and home lives, has identified four areas of concern which need to be addressed if dementia in the countryside is to be managed.
Women with dementia receive less medical attention
Women with dementia have fewer visits to the GP, receive less health monitoring and take more potentially harmful medication than men with dementia, new UCL research reveals.
Dementia on the downslide, especially among people with more education
In a hopeful sign for the health of the nation's brains, the percentage of American seniors with dementia is dropping, a new study finds.
New study suggests rethink of dementia causes
University of Adelaide researchers have developed a new theory for the causes of dementia and other neurodegenerative diseases, involving an out-of-control immune system.
Bleeding stroke associated with onset of dementia
Bleeding within the brain, or intracerebral hemorrhage, was associated with a high risk of developing dementia post stroke, according to research presented at the American Stroke Association's International Stroke Conference 2016.
Dementia: New insights into causes of loss of orientation
The University of Exeter Medical School led two studies, each of which moves us a step closer to understanding the onset of dementia, and potentially to paving the way for future therapies.

Related Dementia Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Jumpstarting Creativity
Our greatest breakthroughs and triumphs have one thing in common: creativity. But how do you ignite it? And how do you rekindle it? This hour, TED speakers explore ideas on jumpstarting creativity. Guests include economist Tim Harford, producer Helen Marriage, artificial intelligence researcher Steve Engels, and behavioral scientist Marily Oppezzo.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".