Navigation Links
Researchers reveal the dual role of brain glycogen
Date:2/27/2014

In 2007, in an article published in Nature Neuroscience, scientists at the Institute for Research in Biomedicine (IRB Barcelona) headed by Joan Guinovart, an authority on glycogen metabolism, reported that in Lafora Disease (LD), a rare and fatal neurodegenerative condition that affects adolescents, neurons die as a result of the accumulation of glycogenchains of glucose. They went on to propose that this accumulation is the root cause of this disease.

The breakthrough of this paper was two-sided: first, the researchers established a possible cause of LD and therefore were able to point to a plausible therapeutic target, and second, they discovered that neurons have the capacity to store glycogenan observation that had never been madeand that this accumulation was toxic.

Some scientists sceptical about the article upheld that the glycogen deposits were not cause by the neurodegeneration but were a consequence of another, more important, cell imbalance, such as a down deregulation of autophagythe cell recycling and cleaning programme. In several articles, Guinovart's "Metabolic engineering and diabetes therapy" group has recently brought to light evidence of the toxicity of glycogen deposits for LD patients, and has now provided irrefutable data.

In an article published at the beginning of February in Human Molecular Genetics, with the associate researcher Jordi Duran as first author, the scientists show that in LD the accumulation of glycogen directly causes neuronal death and triggers cell imbalances such a decrease in autophagy and synaptic failure. All these alterations lead to the symptoms of LD, such as epilepsy.

Glycogen, a Trojan horse for neurons?

There was still a greater mystery to be solved. Was glycogen synthase truly a Trojan horse for neurons, as apparently established in the article in Nature Neuroscience? That is to say, was the accumulation of glycogen always fatal for cells, thus explaining why their glycogen synthesis machinery is silenced? The inevitable question was then why these cells had such machinery.

In another paper published in Journal of Cerebral Blood Flow & Metabolism, part of the Nature Group, the researchers provided the first evidence that neurons constantly store glycogen but in a different way: accumulating small amounts and using it as quickly as it becomes available. In this regard, the scientists set up new, more sensitive, analytical techniques to confirm that the machinery responsible for glycogen synthesis and degradation existed. In summary, they showed that, in small amounts, glycogen is beneficial for neurons.

"For example, while the liver accumulates glycogen in large amounts and releases it slowly to maintain blood sugar levels, above all when we sleep, neurons synthesize and degrade small amounts of this polysaccharide continuously. They do not use it as an energy store but as a rapid and small, but constant, source of energy," explains Guinovart, also senior professor at the University of Barcelona (UB).

To observe the action of glycogen, the scientists forced cultured mouse neurons to survive under oxygen depletion. They demonstrated that the first cells to die were those in which the capacity to synthesise glycogen had been removed. The same experiments were performed in collaboration with Marco Miln's "Development and growth control" group in the in vivo model of the fruit fly Drosophila melanogaster. These tests led to the same conclusions.

The researchers postulated that glycogen is a lifeguard under oxygen depletion, a condition that leads the brains to shut down and that often occurs at birth and in cerebral infarctions in adults, which leads to severe consequences, such a cerebral paralysis.

"It is the first function of glycogen that we have discovered in neurons, but we still have to identify its function in normal conditions and establish how the mechanism works," says Jordi Duran. Postdoctoral researcher Isabel Saez is the first author of the article out today, which involved the collaboration of ICREA Research Professor Marco Miln's lab.

The beneficial and toxic roles of brain glycogen are currently the focus of main research lines conducted by Joan Guinovart's lab.


'/>"/>
Contact: Sònia Armengou
armengou@irbbarcelona.org
34-934-037-255
Institute for Research in Biomedicine (IRB Barcelona)
Source:Eurekalert  

Related biology news :

1. Study by UC Santa Barbara researchers suggests that bacteria communicate by touch
2. UC Santa Barbara researchers discover genetic link between visual pathways of hydras and humans
3. Researchers attempt to solve problems of antibiotic resistance and bee deaths in one
4. UNH researchers find African farmers need better climate change data to improve farming practices
5. Ottawa researchers to lead world-first clinical trial of stem cell therapy for septic shock
6. Researchers uncover molecular pathway through which common yeast becomes fungal pathogen
7. Researchers print live cells with a standard inkjet printer
8. Columbia Engineering and Penn researchers increase speed of single-molecule measurements
9. Researchers reveal how a single gene mutation leads to uncontrolled obesity
10. Researchers discover novel therapy for Crohns disease
11. New paper by Notre Dame researchers describes method for cleaning up nuclear waste
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Researchers reveal the dual role of brain glycogen
(Date:3/31/2016)... 31, 2016  Genomics firm Nabsys has completed a ... Barrett Bready , M.D., who returned to the company ... technical leadership team, including Chief Technology Officer, John ... Steve Nurnberg and Vice President of Software and Informatics, ... Dr. Bready served as CEO of Nabsys ...
(Date:3/23/2016)... , March 23, 2016 ... Interesse erhöhter Sicherheit Gesichts- und Stimmerkennung mit ... Inc. (NASDAQ: MESG ), ein ... dass das Unternehmen mit SpeechPro zusammenarbeitet, um ... der Finanzdienstleistungsbranche, wird die Möglichkeit angeboten, im ...
(Date:3/22/2016)... , PROVO and ... Newborn Screening Ontario (NSO), which operates the highest sample ... molecular testing, and Tute Genomics and UNIConnect, leaders in ... respectively, today announced the launch of a project to ... (NGS) testing panel. NSO has been ...
Breaking Biology News(10 mins):
(Date:5/25/2016)... ... May 25, 2016 , ... Lady had been battling ... her cruciate ligament in her left knee. Lady’s owner Hannah sought the help of ... board-certified veterinary surgeon, to repair her cruciate ligament and help with the pain of ...
(Date:5/24/2016)... May 24, 2016   MedyMatch Technology Ltd ., the ... intelligence, real-time decision support tools in the emergency room, announced ... 2016 Israeli Advanced Technology Industries (IATI) BioMed Conference. ... 15th National Life Sciences and Technology Week, and ... Intercontinental Hotel in Tel Aviv, Israel . ...
(Date:5/23/2016)... ... ... need for blood donations in South Texas and across the nation is growing. , But ... blood donations are on the decline. In fact, donations across the country are at their ... Texas in the last four years alone. , There is no substitute for blood. , ...
(Date:5/23/2016)... -- Oxitec CEO Hadyn Parry will ... ET before the United States House Committee on Science, Space ... in controlling the spread of the Aedes aegypti ...      (Logo: http://photos.prnewswire.com/prnh/20150630/227348 ) Oxitec has ... Trials in Brazil , Panama ...
Breaking Biology Technology: