SÃO PAULO, SP (FOLHAPRESS) – The main hypothesis on the development of Alzheimer’s disease is increasingly criticized, to the point that scientists are wondering if they have followed a false trail in the search for a drug over the past decades.
THE “Amyloid cascade” theory served as the basis for the last 20 years of investigation into this degenerative disease, but without tangible results.
Although it is the best known and most common dementia, its causes and course remain unknown.
One of the few certainties is that people with Alzheimer’s have plaques of proteins, called amyloids, which form around neurons and destroy them.
But do these plates represent the main cause? Or could it be the consequence of another pathology? This is the main question of scientists.
According to the “cascade” theory, Alzheimer’s disease is due to the formation of these plaques. However, this hypothesis raises more and more doubts, three decades after its formulation by the British biologist John Hardy.
A study published this Thursday (2) by the journal Nature Neuroscience casts doubt on the role of protein plaques and supports the hypothesis that, in reality, Alzheimer’s disease occurs inside neurons, and not outside them. ‘outside.
This publication, based on analyzes in genetically modified mice, points to a possible dysfunction of lysosomes, cellular organelles which are used to “digest” these useless or degraded components.
“These new elements challenge the beliefs we had about the functioning of Alzheimer’s disease”, said American biologist Ralph Nixon, who supervised the study at New York University.
This research does not in itself change the scientific consensus on Alzheimer’s disease, the hypothesis must be confirmed in humans. However, it is part of a general questioning of the “cascade” theory, which has guided the efforts of the pharmaceutical industry in vain.
The American laboratory Biogen has developed the only drug authorized against this degenerative disease, but its effectiveness is questioned by the scientific community.