A team of scientists from the Center for Research and Advanced Studies (CINVESTAV) of the National Polytechnic Institute (IPN) found that the concentration of abnormal proteins in Alzheimer’s patients, which serve in a first place as neurons’ defense mechanism, however, it becomes a pathology that kills them.
This finding may help uncover what triggers Alzheimer’s disease and other dementias, the coordinator of the National Brain Bank, José Luna Muñoz, said in a statement.
The specialist explained that the Tau protein is responsible for maintaining optimally the cytoskeleton of neuronal axon, which is the “net” that allows them to connect among themselves.
But when Alzheimer’s or other dementia develops, this protein is altered causing changes, such as hyperphosphorylation and truncation, leading to the death of the neuron.
This disease has demonstrated the action of proteolytic enzymes, which favor the degradation of proteins in the programed cell death, also called apoptosis mechanism.
Luna Muñoz said that these enzymes fragment Tau protein, promoting their polymerization in filaments highly resistant to proteolysis, and having a mass of filaments in the cell body, generates cell death.
And when filament packages are exposed in the extracellular space, specific brain areas are disconnected.
In a previous study, the group of scientists demonstrated that, in the early stages of tau processing in Alzheimer’s disease, the N-terminal part of the molecule undergoes a characteristic cascade of phosphorylation and progressive misfolding of the proteins resulting in a structural conformation detected by Alz-50.
In their latest study of AD brain tissue, they have found that C-terminal truncation of tau at Asp-421 was an early event in tau aggregation and analyzed the relationship between phospho-dependent tau epitopes located at the C-terminus with truncation at Glu-391.
The study was published in the journal Frontiers in Neuroscience.
Source: Notimex, Frontiers
