Final answer:
Decreased alpha-secretase activity leads to increased production of β-Amyloid (Aβ) (1-42), which is true, as this enzyme typically prevents the formation of amyloidogenic peptides that aggregate into plaques characteristic of Alzheimer's disease.
Step-by-step explanation:
The statement that decreased alpha-secretase activity can result in increased production of β-Amyloid (Aβ) (1-42) is true. Alpha-secretase is involved in the non-amyloidogenic pathway, wherein it cleaves the amyloid precursor protein (APP) within the Aβ domain, thus preventing the formation of Aβ. When there is decreased alpha-secretase activity, APP is more likely to be processed by beta-secretase and gamma-secretase, leading to increased production of amyloidogenic peptides such as Aβ(1-42), which can aggregate into the characteristic beta-amyloid plaques seen in Alzheimer's disease (AD).
Plaques consisting primarily of extracellular aggregations of beta-amyloid (Aβ) peptide fragments are classic indications of AD. The role of alpha-secretase in cleaving APP is crucial, and its reduced activity leads to the pathological accumulation of Aβ(1-42), contributing to the formation of plaques and the neurodegeneration observed in AD patients. Thus, a balancing act between the different secretases is essential for the proper regulation of Aβ levels and prevention of plaque formation which is associated with AD pathogenesis.