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:2/21/2017)... , February 21, 2017 Der ... US-Dollar wachsen. Nach einem Gespräch mit mehr als 50 Vertretern ... Hindernisse zu überwinden gilt, um diese Prognose zu realisieren. ... ... die Mobilisierung der finanziellen Mittel für die Biobank, die ...
(Date:2/10/2017)... -- Research and Markets has announced the ... Scientific and Commercial Aspects" to their offering. ... Biomarkers play ... therapy for selection of treatment as well for monitoring the ... disease in modern medicine. Biochip/microarray technologies and next generation sequencing ...
(Date:2/8/2017)... , Feb. 7, 2017 The ... largely by the confluence of organizations, desires to ... for knowledge-based systems (password and challenge questions), biometrics ... and government systems. The market is driven by ... demarcation between consumer and enterprise uses cases, with ...
Breaking Biology News(10 mins):
(Date:2/23/2017)... ... February 23, 2017 , ... Brain Sentinel, Inc. has ... the SPEAC® System, the Brain Sentinel® Seizure Monitoring and Alerting System. The adjunctive ... during periods of rest. A lightweight, non-invasive monitor is placed on the belly ...
(Date:2/23/2017)... INDIANAPOLIS, Ind. (PRWEB) , ... February 23, 2017 ... ... Commercialization Award during the 12th annual Inventors Recognition Reception at Purdue Research ... annually to a faculty member in recognition of outstanding contributions to, and success ...
(Date:2/23/2017)... Winston-Salem, NC (PRWEB) , ... February 23, 2017 , ... ... pleased to announce a new partnership with Compass Research . GGI's mission is ... gifting a vaccine to a child in need in honor of each clinical trial ...
(Date:2/23/2017)... SAN DIEGO , Feb. 23, 2017 /PRNewswire/ ... protein research tools, announced the acquisition of GenWay ... with a comprehensive service and product offering for ... "This acquisition will facilitate growth and enhance capabilities ... proteins, antibodies, and ELISA assays will nicely complement ...
Breaking Biology Technology: