Two peptides were already known for their role in Alzheimer’s disease. Amyloid-eta, discovered by a Franco-German team, would also have an effect on cognitive decline.
Amyloid-beta (β), well known to cause Alzheimer’s disease, has just discovered a cousin: amyloid-eta (η). This peptide is described in the prestigious journal Nature by a Franco-German team. Long ignored, it nevertheless plays an important role in the development of symptoms such as memory loss or cognitive decline. And it is present in much greater amounts in the brain than the beta form.
Like amyloid-β, its cousin amyloid-η is a product of the APP protein. It is naturally present in the brain, and in greater numbers. “We have discovered a new actor”, summarizes the Dr Hélène Marie, co-author of the study and researcher at the Institute of Molecular and Cellular Pharmacology (IPMC), contacted by Why actor. Because for 30 years, medical research has focused on beta-amyloid. “There was still some information that pointed to other peptides from the APP protein, but people weren’t interested. They have been neglected ”, explains the Dr Marie. It was the German team that discovered amyloid-eta. The French have managed to explain how it works in the brain.
Clinical trials to review
The recently discovered peptide clumps together and disrupts the functioning of neurons. “We have shown that amyloid-η significantly disrupts a cellular mechanism at the base of memory, which is called long-term potentiation, details Helene marie. It has been shown to decrease the ability of synapses to strengthen their communication during a learning process. However, this compound has been found in large quantities in the brains of mice modified to develop Alzheimer’s disease and of human patients.
Research also shows a point in common between the two cousin peptides: they reduce the strengthening of synapses necessary for memorization. On the other hand, amyloid-η makes neurons more difficult to excite, while its more famous cousin causes neuronal hyperactivity.
This study provides a better understanding of the mechanisms of Alzheimer’s disease. It is also of interest to researchers involved in various clinical trials. Some try to inhibit beta-secretase, which reduces the production of amyloid-β. “It turns out that when it was inhibited in the laboratory in mice, we can show that there is a strong increase in amyloid-η,” relates the Dr Marie. It could be toxic, so it is important to understand all the processes before continuing some random trials. We haven’t figured it out yet. “
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