Syndicate content

Archive - May 21, 2013

Date

Scientists ID a Molecular Trigger for Alzheimer’s Disease

Researchers have pinpointed a catalytic trigger for the onset of Alzheimer’s disease – when the fundamental structure of a protein molecule changes to cause a chain reaction that leads to the death of neurons in the brain. For the first time, scientists at Cambridge’s Department of Chemistry have been able to map in detail the pathway that generates “aberrant” forms of proteins that are at the root of neurodegenerative conditions such as Alzheimer’s. They believe the breakthrough is a vital step closer to increased capabilities for earlier diagnosis of neurological disorders such as Alzheimer’s and Parkinson’s, and opens up possibilities for a new generation of targeted drugs, as scientists say they have uncovered the earliest stages of the development of Alzheimer’s that drugs could possibly target. The study, published online on May 20, 2013 in PNAS, is a milestone in the long-term research established in Cambridge by Professor Christopher Dobson and his colleagues, following the realization by Dr. Dobson of the underlying nature of protein ‘misfolding’ and its connection with disease over 15 years ago. The research is likely to have a central role to play in diagnostic and drug development for dementia-related diseases, which are increasingly prevalent and damaging as populations live longer. “There are no disease-modifying therapies for Alzheimer’s and dementia at the moment, only limited treatment for symptoms. We have to solve what happens at the molecular level before we can progress and have real impact,” said Dr Tuomas Knowles, lead author of the study and long-time collaborator of Professor Dobson’s. “We’ve now established the pathway that shows how the toxic species that cause cell death, the oligomers, are formed.

Scientists Chart Astounding Impact of Insulin on Cells

Australian scientists have charted the path of insulin action in cells in precise detail like never before. This provides a comprehensive blueprint for understanding what goes wrong in diabetes. The breakthrough study, conducted by Ph.D. student Sean Humphrey and Professor David James from Sydney’s Garvan Institute of Medical Research, was published online on May 16, 2013 in Cell Metabolism. First discovered in 1921, the insulin hormone plays a very important role in the body because it helps us lower blood sugar after a meal, by enabling the movement of sugar from the blood into cells. Until now, although scientists have understood the purpose of insulin at a broad level, they have struggled to understand exactly how it achieves its task. Sophisticted analytical devices called mass spectrometers now provide the tool that has been missing – the means of looking into the vastly complex molecular maze that exists in every single cell in the human body. These powerful devices have opened up a field known as ‘proteomics,’ the study of proteins on a very large scale. Proteins represent the working parts of cells, using energy to perform essential functions such as muscle contraction, heartbeat, or even memory. Each cell houses multiple copies of between 10,000 and 12,000 protein types, which communicate with each other using various methods, the most common of which is a process known as ‘phosphorylation.’ Phosphate molecules are deliberately added to proteins in order to convey information, or else change the protein’s function. Each of the protein types in a cell has up to 20 potential ‘phosphorylation sites,’ regions to which a phosphate molecule can be added. This pushes the total number of possible cell states from one moment to the next into the billions.