title: Amyloid beta inhibits ectodomain shedding of N-cadherin via down-regulation of cell-surface NMDA receptor.
abstract: Dysfunction in the synapse is recognized as an early and the primary pathological process in Alzheimer's disease (AD). N-cadherin, an essential adhesion molecule for excitatory synaptic contact, forms a complex with presenilin 1 (PS1) and beta-catenin in the synaptic membrane. N-cadherin is sequentially cleaved by ADAM10 and PS1/gamma-secretase, producing a cytoplasmic fragment, N-cadherin C-terminal fragment (Ncad/CTF2) after NMDA receptor stimulation [Marambaud P, Wen PH, Dutt A, Shioi J, Takashima A, Siman R, Robakis NK (2003) A CBP binding transcriptional repressor produced by the PS1/epsilon-cleavage of N-cadherin is inhibited by PS1 FAD mutations. Cell 114:635-645; Reiss K, Maretzky T, Ludwig A, Tousseyn T, de Strooper B, Hartmann D, Saftig P (2005) ADAM10 cleavage of N-cadherin and regulation of cell-cell adhesion and beta-catenin nuclear signalling. EMBO J 24:1762]. Ncad/CTF2 translocates to the nucleus together with beta-catenin to enhance beta-catenin nuclear signaling [Uemura K, Kihara T, Kuzuya A, Okawa K, Nishimoto T, Bito H, Ninomiya H, Sugimoto H, Kinoshita A, Shimohama S (2006a) Activity-dependent regulation of beta-catenin via epsilon-cleavage of N-cadherin. Biochem Biophys Res Commun 345:951-958]. To examine whether an impairment of N-cadherin metabolism is involved in AD pathogenesis, we investigated the effect of amyloid beta peptide (Abeta) treatment on sequential N-cadherin cleavage. Here, we demonstrate that both synthetic and cell-derived Abeta species inhibit ectodomain shedding of mouse N-cadherin. Inhibition of N-cadherin cleavage by Abeta treatment was suggested to be mediated by the enhanced endocytosis of NMDA receptor, resulting in reduced turnover of N-cadherin. Since both N-cadherin and beta-catenin are essential for synaptic plasticity, impairment of N-cadherin cleavage caused by Abeta may underlie the synapse toxicity involved in AD pathogenesis.
authors.affiliation: Horizontal Medical Research Organization, Kyoto University Graduate School of Medicine, Kyoto, Japan 606-8507.
authors.forename: K
authors.initials: K
authors.lastname: Uemura
authors.forename: A
authors.initials: A
authors.lastname: Kuzuya
authors.forename: N
authors.initials: N
authors.lastname: Aoyagi
authors.forename: K
authors.initials: K
authors.lastname: Ando
authors.forename: Y
authors.initials: Y
authors.lastname: Shimozono
authors.forename: H
authors.initials: H
authors.lastname: Ninomiya
authors.forename: S
authors.initials: S
authors.lastname: Shimohama
authors.forename: A
authors.initials: A
authors.lastname: Kinoshita
mesh_terms: D051722:ADAM Proteins / Q000494:pharmacology; D000072197:ADAM10 Protein; D053829:Amyloid Precursor Protein Secretases / Q000494:pharmacology; D016229:Amyloid beta-Peptides / Q000494:pharmacology*; D000818:Animals; D015820:Cadherins / Q000378:metabolism*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D006224:Cricetinae; D003412:Cricetulus; D015536:Down-Regulation / Q000187:drug effects*; D004347:Drug Interactions; D004622:Embryo, Mammalian; D018683:Excitatory Amino Acid Agents / Q000494:pharmacology; D006801:Humans; D008565:Membrane Proteins / Q000494:pharmacology; D051379:Mice; D008954:Models, Biological; D009154:Mutation; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D014162:Transfection
chemical_list: D016229:Amyloid beta-Peptides; D015820:Cadherins; D018683:Excitatory Amino Acid Agents; D008565:Membrane Proteins; D016194:Receptors, N-Methyl-D-Aspartate; D053829:Amyloid Precursor Protein Secretases; D051722:ADAM Proteins; D000072197:ADAM10 Protein; C491236:ADAM10 protein, human