S2‐02–05: Anti‐abeta antibodies in Alzheimer's disease mouse models

calpain activation with A plaque formation in brains from both AD patients and transgenic (Tg) mice overexpressing amyloid precursor protein (APP). The mice also exhibited axonal termini dynamically misdirected to calpain activation-positive A plaques. Consistently, cerebrospinal fluids from Tg mice and AD patients contained greater quantity of calpain-cleaved spectrin than controls. Genetic deficiency of calpastatin (CS), calpain-specific inhibitor protein, augmented A amyloidosis, tau phosphorylation, microgliosis, somato-dendritic dystrophy and mortality in APP-Tg mice. In contrast, brain-specific CS overexpression resulted in opposite phenotypes. Conclusions: These observations indicate that calpain activation may underlie A -triggered pathological cascade and thus shall become a relevant pharmacological target in the treatment of AD.