Peptide Discovery Could Lead to New Alzheimer's Treatment
Scientists have uncovered some surprising characteristics of a peptide that indicate it may have an important role in the treatment and prevention of Alzheimer’s disease. Amyloid-beta peptide 43 (Aβ43) is more toxic to nerve cells (neurotoxic) and more plentiful than other amyloids studied in Alzheimer’s research.
Could this peptide help in prevention of Alzheimer’s?
Alzheimer’s disease is a progressive disease and the most common type of dementia. Between 2000 and 2008, deaths from Alzheimer’s increased 66 percent, and it is the fifth leading cause of death among people 65 and older in the United States. Today about 5 million Americans have the disease, but by 2050, it is estimated the number will reach 16 million.
The disease is characterized by the presence of two abnormal structures called senile plaques and tangles. The main constituent of plaques are protein fragments called amyloid-beta peptides, which accumulate in the spaces between nerve cells. Tangles are twisted fibers of another protein called tau that build up inside cells in the brain.
A fair amount of research has been done on two types of amyloid-beta peptides, Aβ40 and Aβ42, which are associated with genetic mutations that cause early-onset Alzheimer’s. These two peptides are not the only ones present in the brain of people with Alzheimer’s, and this latest study focused on Aβ43.
Using a mouse model in which the animals were made to over produce Aβ43, scientists at the Riken Brain Science Institute and their collaborators studied the role of this peptide in Alzheimer’s disease. They then utilized a highly sensitive method to identify concentrations of Aβ40, 42, and 43.
The scientists found that Aβ43 is more prevalent in the brains of Alzheimer’s patients than is Aβ40, is more neurotoxic than Aβ42, and has a greater tendency to accumulate and speed up amyloid pathology than the other peptides. Also of interest is that levels of Aβ43 appear to increase with age, which mirrors the onset of Alzheimer’s.
Thus far, effective ways to slow down, prevent, or cure Alzheimer’s disease have eluded researchers. The discoveries concerning the peptide Aβ43 suggest this factor could be helpful in the diagnosis of Alzheimer’s disease and possibly lead to new ways to prevent and treat the disease.