Increase of brain Aβ peptides and secretase activity during normal aging in rodent and human.

Normal aging leads to an increase in amyloid beta protein fragments and the activity of a specific enzyme called beta-secretase in the brains of rodents and humans.

As we age, our brains undergo various changes, and one notable observation is the accumulation of a protein fragment known as amyloid beta. This buildup has long been associated with age-related cognitive decline and neurodegenerative conditions. Recent research sheds light on a potential contributor to this phenomenon by investigating the role of an enzyme called beta-secretase. This enzyme is crucial because it helps cleave a larger protein, ultimately leading to the production of amyloid beta. The study found that the activity of beta-secretase significantly increases with age in the brains of different species, including mice, monkeys, and humans. Interestingly, this increase in enzyme activity occurred without a corresponding rise in the total amount of the beta-secretase protein itself, suggesting that the existing enzyme becomes more active over time. This heightened activity was directly linked to higher levels of amyloid beta in specific brain regions. These findings suggest that an age-related boost in the activity of this particular enzyme could contribute to the increased production and accumulation of amyloid beta in the brain, potentially influencing the risk for conditions like Alzheimer’s disease.