A new study published in the online open access journal BMC Biology suggests that disturbances in membrane cholesterol may be the mechanism by which prions cause neurodegeneration and could point to a role for cholesterol in other neurodegenerative diseases.
It is widely believed that prions (protein only infectious material) are the cause of rare progressive neurodegenerative disorders that affect both humans and animals. A prion is an infectious agent made solely of protein. However what is not known is how the prions damage brain cells (neurons).
Dr Clive Bate and colleagues from the Royal Veterinary College in the UK compared the amounts of protein and cholesterol in prion-infected neuronal cell lines and primary cortical neurons with uninfected controls. Protein levels were similar but the amount of total cholesterol (a mixture of free and esterified cholesterol) was significantly higher in the infected cell lines. The cholesterol balance was also affected: the amount of free cholesterol increased but that of cholesterol esters reduced, suggesting that prion infection affects cholesterol regulation.
The team attempted to reproduce the effects of prions on cholesterol levels, by stimulating cholesterol biosynthesis or by adding exogenous cholesterol. Both approaches resulted in increased amounts of cholesterol esters but not of free cholesterol. The free cholesterol is thought to affect the function of the cell membranes and to lead to abnormal activation of phospholipase A2, an enzyme implicated in the depletion of neurons in prion and Alzheimer’s disease.
Studies have recently shown that the controlling cholesterol levels within the brain is critical in limiting the development of neurodegenerative diseases such as Alzheimer’s, Parkinson’s and prion diseases, multiple sclerosis, and senile dementia.
This study now gives far more specific insight into the kind of mechanisms at work. Dr Bate stated: “Our observations raise the possibility that disturbances in membrane cholesterol induced by prions are major triggering events in the neuropathogenesis of prion diseases”.
Atacama Desert: Some lichens can meet their need for water from air humidity
17.07.2019 | Technische Universität Kaiserslautern
Megakaryocytes act as „bouncers“ restraining cell migration in the bone marrow
16.07.2019 | Rudolf-Virchow-Zentrum für Experimentelle Biomedizin der Universität Würzburg
Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.
Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...
For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.
Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...
An international research group led by scientists from the University of Bayreuth has produced a previously unknown material: Rhenium nitride pernitride. Thanks to combining properties that were previously considered incompatible, it looks set to become highly attractive for technological applications. Indeed, it is a super-hard metallic conductor that can withstand extremely high pressures like a diamond. A process now developed in Bayreuth opens up the possibility of producing rhenium nitride pernitride and other technologically interesting materials in sufficiently large quantity for their properties characterisation. The new findings are presented in "Nature Communications".
The possibility of finding a compound that was metallically conductive, super-hard, and ultra-incompressible was long considered unlikely in science. It was...
An interdisciplinary research team at the Technical University of Munich (TUM) has built platinum nanoparticles for catalysis in fuel cells: The new size-optimized catalysts are twice as good as the best process commercially available today.
Fuel cells may well replace batteries as the power source for electric cars. They consume hydrogen, a gas which could be produced for example using surplus...
The fly agaric with its red hat is perhaps the most evocative of the diverse and variously colored mushroom species. Hitherto, the purpose of these colors was...
24.06.2019 | Event News
29.04.2019 | Event News
17.04.2019 | Event News
17.07.2019 | Physics and Astronomy
17.07.2019 | Life Sciences
17.07.2019 | Information Technology