N-methyl-d-aspartate receptor-mediated processing of beta-amyloid precursor protein in rat hippocampal slices: in vitro--superfusion study.
Abnormal proteolytic degradation of the beta amyloid precursor protein (beta-APP) may result in accumulation of potentially neurotoxic beta amyloid (betaA). The role of various receptors in the regulation of beta-APP processing has been suggested. This study aimed to determine how NMDA receptors and Ca2+ ions regulate proteolysis of beta-APP in rat hippocampus in vitro. Adult rat hippocampal slices were superfused with NMDA-containing media, and immunoreactivity of soluble beta-APP derivatives was detected in dialysates. Application of 100 microM and 250 microM NMDA for 20 min in Ca2+-containing medium induced dose-dependent release of aminoterminal beta-APP derivatives, and a fragment of Abeta sequence, whereas carboxy-terminal fragments of beta-APP were only slightly detected. This indicates activation of beta-APP processing, and release of its soluble cleavage products. This effect was inhibited by NMDA receptor antagonist 1 microM MK-801 and 100 microM CPP in Ca2+-free medium, thus indicating that NMDA receptors and calcium ions mediate proteolytic non-amyloidogenic degradation of the beta-APP.
Gordon-Krajcer
Wanda
W
Department of Neurochemistry, Medical Research Centre, Polish Academy of Sciences, Warszawa.
Salińska
Elzbieta
E
Lazarewicz
Jerzy W
JW
D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D000818:Animals; D006624:Hippocampus / Q000378:metabolism*; D008297:Male; D009924:Organ Culture Techniques; D010477:Perfusion; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*
D016564:Amyloid beta-Protein Precursor; D016194:Receptors, N-Methyl-D-Aspartate