Amyloid-Beta (Aβ)

Category: biomarker

A peptide fragment of the amyloid precursor protein (APP) that forms plaques in Alzheimer's disease brains. The central target of the amyloid hypothesis.

Mechanism Detail

APP is cleaved by β-secretase and γ-secretase to produce Aβ peptides (Aβ40, Aβ42). Aβ42 is more aggregation-prone, forming oligomers and protofibrils that are synaptotoxic before aggregating into plaques. The amyloid cascade hypothesis posits that Aβ accumulation triggers tau pathology and neurodegeneration.

Clinical Status

Anti-amyloid antibodies (lecanemab, donanemab) show modest clinical benefit. Aβ PET imaging and CSF biomarkers are diagnostic standards. The amyloid hypothesis remains debated.

Relevant Diseases

• Alzheimer's Disease

Relevant Therapies

• Cell-Based Therapies
• Nutraceuticals

Related Terms

• Lecanemab
• Tau protein
• Amyloid plaques
• Beta-secretase