Naphthoquinone-tyrptophan reduces neurotoxic Aβ*56 levels and improves cognition in Alzheimer's disease animal model

Autor: R. Scherzer-Attali, D. Farfara, I. Cooper, A. Levin, T. Ben-Romano, D. Trudler, M. Vientrov, R. Shaltiel-Karyo, D.E. Shalev, N. Segev-Amzaleg, E. Gazit, D. Segal, D. Frenkel
Jazyk: angličtina
Rok vydání: 2012
Předmět:
Zdroj: Neurobiology of Disease, Vol 46, Iss 3, Pp 663-672 (2012)
Druh dokumentu: article
ISSN: 1095-953X
DOI: 10.1016/j.nbd.2012.03.005
Popis: An increasing body of evidence indicates a role for oligomers of the amyloid-β peptide (Aβ) in the neurotoxicity of this peptide and the pathology of Alzheimer's disease (AD). Several neurotoxic oligomeric forms of Aβ have been noted ranging from the larger Amyloid β-Derived Diffusible Ligands (ADDLs) to smaller trimers and dimers of Aβ. More recently a dodecameric form of Aβ with a 56 kDa molecular weight, denoted Aβ*56, was shown to cause memory impairment in AD model mice. Here, we present for the first time a potential therapeutic strategy for AD that targets the early stages in the formation of neurotoxic Aβ*56 oligomers using a modified quinone-Tryptophan small molecule N-(3-chloro-1,4-dihydro-1,4-dioxo-2-naphthalenyl)-L-Tryptophan (Cl-NQTrp). Using NMR spectroscopy we show that this compound binds the aromatic recognition core of Aβ and prevents the formation of oligomers. We assessed the effect of Cl-NQTrp in vivo in transgenic flies expressing Aβ1-42 in their nervous system. When these flies were fed with Cl-NQTrp a marked alleviation of their Aβ-engendered reduced life span and defective locomotion was observed. Finally, intraperitoneal injection of Cl-NQTrp into an aggressive AD mouse model reduced the level of the Aβ*56 species in their brain and reversed their cognitive defects. Further experiments should assess whether this is a direct effect of the drug in the brain or an indirect peripheral effect. This is the first demonstration that targeted reduction of Aβ*56 results in amelioration of AD symptoms. This second generation of tryptophan-modified naphthoquinones could therefore serve as potent disease modifying therapeutic for AD.
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