Alzheimer's disease (AD) is the most abundant tauopathy and is characterized by Aβ-derived plaques and tau-derived tangles, resulting from the unfolding of the corresponding monomeric subunits into ordered β-sheet oligomers and fibrils. Intervening in the toxic aggregation process is a promising therapeutic approach, but, to date, a disease-modifying therapy is neither available for AD nor for other tauopathies. Along these lines, we have previously demonstrated that a small naphthoquinone-tryptophan hybrid, termed NQTrp, is an effective modulator of tauopathy in vitro and in vivo. However, NQTrp is difficult to synthesize and is not very stable. Therefore, we tested whether a more stable and easier-to-synthesize modified version of NQTrp, containing a Cl ion, namely Cl-NQTrp, is also an effective inhibitor of tau aggregation in vitro and in vivo. Cl-NQTrp was previously shown to efficiently inhibit the aggregation of various amyloidogenic proteins and peptides. We demonstrate that Cl-NQTrp inhibits the in vitro assembly of PHF6, the aggregation-prone fragment of tau, and alleviates tauopathy symptoms in a transgenic Drosophila model through the inhibition of tau aggregation-engendered toxicity. These results suggest that Cl-NQTrp could be a unique potential therapeutic for AD since it targets aggregation of both Aβ and tau.

Keywords:
Tau protein, PHF6, Protein misfolding, Drosophilamelanogaster, Cl-NQTrp, Protein aggregation, Alzheimer’s disease
1.
Walsh DM, Selkoe DJ: Deciphering the molecular basis of memory failure in Alzheimer's disease. Neuron 2004;44:181-193.
2.
Van Cauwenberghe C, Van Broeckhoven C, Sleegers K: The genetic landscape of Alzheimer disease: clinical implications and perspectives. Genet Med 2016;18:421-430.
3.
Chin J: Selecting a mouse model of Alzheimer's disease. Methods Mol Biol 2011;670:169-189.
4.
Braak H, Braak E: Staging of Alzheimer's disease-related neurofibrillary changes. Neurobiol Aging 1995;16:271-278; discussion 278-284.
5.
Kosik KS: The molecular and cellular biology of tau. Brain Pathol 1993;3:39-43.
6.
Binder LI, Frankfurter A, Rebhun LI: The distribution of tau in the mammalian central nervous system. J Cell Biol 1985;101:1371-1378.
7.
Gong CX, Iqbal K: Hyperphosphorylation of microtubule-associated protein tau: a promising therapeutic target for Alzheimer disease. Curr Med Chem 2008;15:2321-2328.
8.
Mietelska-Porowska A, Wasik U, Goras M, Filipek A, Niewiadomska G: Tau protein modifications and interactions: their role in function and dysfunction. Int J Mol Sci 2014;15:4671-4713.
9.
Lee VM, Goedert M, Trojanowski JQ: Neurodegenerative tauopathies. Annu Rev Neurosci 2001;24:1121-1159.
10.
Williams DR: Tauopathies: classification and clinical update on neurodegenerative diseases associated with microtubule-associated protein tau. Intern Med J 2006;36:652-660.
11.
Bouchard M, Suchowersky O: Tauopathies: one disease or many? Can J Neurol Sci 2011;38:547-556.
12.
Kruger L, Mandelkow EM: Tau neurotoxicity and rescue in animal models of human tauopathies. Curr Opin Neurobiol 2015;36:52-58.
13.
Iqbal K, Alonso Adel C, Chen S, Chohan MO, El-Akkad E, et al: Tau pathology in Alzheimer disease and other tauopathies. Biochim Biophys Acta 2005;1739:198-210.
14.
Ward SM, Himmelstein DS, Lancia JK, Binder LI: Tau oligomers and tau toxicity in neurodegenerative disease. Biochem Soc Trans 2012;40:667-671.
15.
Lim S, Haque MM, Kim D, Kim DJ, Kim YK: Cell-based models to investigate tau aggregation. Comput Struct Biotechnol J 2014;12:7-13.
16.
Lasagna-Reeves CA, Castillo-Carranza DL, Sengupta U, Clos AL, Jackson GR, et al: Tau oligomers impair memory and induce synaptic and mitochondrial dysfunction in wild-type mice. Mol Neurodegener 2011;6:39.
17.
von Bergen M, Friedhoff P, Biernat J, Heberle J, Mandelkow EM, et al: Assembly of tau protein into Alzheimer paired helical filaments depends on a local sequence motif ((306)VQIVYK(311)) forming beta structure. Proc Natl Acad Sci USA 2000;97:5129-5134.
18.
von Bergen M, Barghorn S, Li L, Marx A, Biernat J, et al: Mutations of tau protein in frontotemporal dementia promote aggregation of paired helical filaments by enhancing local beta-structure. J Biol Chem 2001;276:48165-48174.
19.
Bulic B, Pickhardt M, Schmidt B, Mandelkow EM, Waldmann H, et al: Development of tau aggregation inhibitors for Alzheimer's disease. Angew Chem Int Ed Engl 2009;48:1740-1752.
20.
Frenkel-Pinter M, Richman M, Belostozky A, Abu-Mokh A, Gazit E, et al: Selective inhibition of aggregation and toxicity of a tau-derived peptide using its glycosylated analogues. Chemistry 2016;22:5945-5952.
21.
Frenkel-Pinter M, Tal S, Scherzer-Attali R, Abu-Hussien M, Alyagor I, et al: Naphthoquinone-tryptophan hybrid inhibits aggregation of the tau-derived peptide PHF6 and reduces neurotoxicity. J Alzheimers Dis 2016;51:165-178.
22.
Ho L, Yemul S, Wang J, Pasinetti GM: Grape seed polyphenolic extract as a potential novel therapeutic agent in tauopathies. J Alzheimers Dis 2009;16:433-439.
23.
Gozes I, Schirer Y, Idan-Feldman A, David M, Furman-Assaf S: NAP alpha-aminoisobutyric acid (IsoNAP). J Mol Neurosci 2014;52:1-9.
24.
Mohamed T, Hoang T, Jelokhani-Niaraki M, Rao PP: Tau-derived-hexapeptide 306VQIVYK311 aggregation inhibitors: nitrocatechol moiety as a pharmacophore in drug design. ACS Chem Neurosci 2013;4:1559-1570.
25.
Zheng J, Liu C, Sawaya MR, Vadla B, Khan S, et al: Macrocyclic beta-sheet peptides that inhibit the aggregation of a tau-protein-derived hexapeptide. J Am Chem Soc 2011;133:3144-3157.
26.
Li W, Sperry JB, Crowe A, Trojanowski JQ, Smith AB 3rd, et al: Inhibition of tau fibrillization by oleocanthal via reaction with the amino groups of tau. J Neurochem 2009;110:1339-1351.
27.
Yiannopoulou KG, Papageorgiou SG: Current and future treatments for Alzheimer's disease. Ther Adv Neurol Disord 2013;6:19-33.
28.
Kumar A, Nisha CM, Silakari C, Sharma I, Anusha K, et al: Current and novel therapeutic molecules and targets in Alzheimer's disease. J Formos Med Assoc 2016;115:3-10.
29.
Galimberti D, Scarpini E: Disease-modifying treatments for Alzheimer's disease. Ther Adv Neurol Disord 2011;4:203-216.
30.
Underwood E: Neuroscience. Alzheimer's amyloid theory gets modest boost. Science 2015;349:464.
31.
Patel KR: Biogen's aducanumab raises hope that Alzheimer's can be treated at its source. Manag Care 2015;24:19.
32.
Toyn J: What lessons can be learned from failed Alzheimer's disease trials? Expert Rev Clin Pharmacol 2015;8:267-269.
33.
Bulic B, Pickhardt M, Mandelkow EM, Mandelkow E: Tau protein and tau aggregation inhibitors. Neuropharmacology 2010;59:276-289.
34.
Scherzer-Attali R, Shaltiel-Karyo R, Adalist YH, Segal D, Gazit E: Generic inhibition of amyloidogenic proteins by two naphthoquinone-tryptophan hybrid molecules. Proteins 2012;80:1962-1973.
35.
Gazit E: Mechanisms of amyloid fibril self-assembly and inhibition. Model short peptides as a key research tool. FEBS J 2005;272:5971-5978.
36.
Gazit E: A possible role for pi-stacking in the self-assembly of amyloid fibrils. FASEB J 2002;16:77-83.
37.
Young LM, Saunders JC, Mahood RA, Revill CH, Foster RJ, et al: Screening and classifying small-molecule inhibitors of amyloid formation using ion mobility spectrometry-mass spectrometry. Nat Chem 2015;7:73-81.
38.
Burley SK, Petsko GA: Aromatic-aromatic interaction: a mechanism of protein structure stabilization. Science 1985;229:23-28.
39.
Makin OS, Atkins E, Sikorski P, Johansson J, Serpell LC: Molecular basis for amyloid fibril formation and stability. Proc Natl Acad Sci USA 2005;102:315-320.
40.
Young LM, Saunders JC, Mahood RA, Revill CH, Foster RJ, et al: ESI-IMS-MS: a method for rapid analysis of protein aggregation and its inhibition by small molecules. Methods 2016;95:62-69.
41.
Scherzer-Attali R, Pellarin R, Convertino M, Frydman-Marom A, Egoz-Matia N, et al: Complete phenotypic recovery of an Alzheimer's disease model by a quinone-tryptophan hybrid aggregation inhibitor. PLoS One 2010;5:e11101.
42.
Scherzer-Attali R, Farfara D, Cooper I, Levin A, Ben-Romano T, et al: Naphthoquinone-tryptophan reduces neurotoxic Aβ*56 levels and improves cognition in Alzheimer's disease animal model. Neurobiol Dis 2012;46:663-672.
43.
Frenkel-Pinter M, Tal S, Scherzer-Attali R, Abu-Hussien M, Alyagor I, et al: Naphthoquinone-tryptophan hybrid inhibits aggregation of the tau-derived peptide PHF6 and reduces neurotoxicity. J Alzheimers Dis 2016;51:165-178.
44.
Oakley H, Cole SL, Logan S, Maus E, Shao P, et al: Intraneuronal beta-amyloid aggregates, neurodegeneration, and neuron loss in transgenic mice with five familial Alzheimer's disease mutations: potential factors in amyloid plaque formation. J Neurosci 2006;26:10129-10140.
45.
Shrestha-Dawadi PB, Bittner S, Fridkin M, Rahimipour S: On the synthesis of naphthoquinonyl heterocyclic amino acids. Synthesis 1996;12:1468-1472.
46.
Chatterjee S, Sang TK, Lawless GM, Jackson GR: Dissociation of tau toxicity and phosphorylation: role of GSK-3β, MARK and Cdk5 in a Drosophila model. Hum Mol Genet 2009;18:164-177.
47.
Shaltiel-Karyo R, Frenkel-Pinter M, Egoz-Matia N, Frydman-Marom A, Shalev DE, et al: Inhibiting α-synuclein oligomerization by stable cell-penetrating β-synuclein fragments recovers phenotype of Parkinson's disease model flies. PLoS One 2010;5:e13863.
48.
Moloney A, Sattelle DB, Lomas DA, Crowther DC: Alzheimer's disease: insights from Drosophila melanogaster models. Trends Biochem Sci 2010;35:228-235.
49.
Sang TK, Jackson GR: Drosophila models of neurodegenerative disease. NeuroRx 2005;2:438-446.
50.
Wittmann CW, Wszolek MF, Shulman JM, Salvaterra PM, Lewis J, et al: Tauopathy in Drosophila: neurodegeneration without neurofibrillary tangles. Science 2001;293:711-714.
51.
Brand AH, Perrimon N: Targeted gene expression as a means of altering cell fates and generating dominant phenotypes. Development 1993;118:401-415.
52.
Lu B, Vogel H: Drosophila models of neurodegenerative diseases. Annu Rev Pathol 2009;4:315-342.
53.
Ephrussi B, Herold JL: Studies of eye pigments of Drosophila. I. Methods of extraction and quantitative estimation of the pigment components. Genetics 1944;29:148-175.
54.
Crowther DC, Kinghorn KJ, Miranda E, Page R, Curry JA, et al: Intraneuronal Aβ, non-amyloid aggregates and neurodegeneration in a Drosophila model of Alzheimer's disease. Neuroscience 2005;132:123-135.
55.
Frydman-Marom A, Levin A, Farfara D, Benromano T, Scherzer-Attali R, et al: Orally administrated cinnamon extract reduces beta-amyloid oligomerization and corrects cognitive impairment in Alzheimer's disease animal models. PLoS One 2011;6:e16564.
56.
Ali YO, Ruan K, Zhai RG: NMNAT suppresses tau-induced neurodegeneration by promoting clearance of hyperphosphorylated tau oligomers in a Drosophila model of tauopathy. Hum Mol Genet 2012;21:237-250.
57.
Sun M, Chen L: Studying tauopathies in Drosophila: a fruitful model. Exp Neurol 2015;274(pt A):52-57.
58.
Klafki HW, Staufenbiel M, Kornhuber J, Wiltfang J: Therapeutic approaches to Alzheimer's disease. Brain 2006;129:2840-2855.
59.
Selkoe DJ: Translating cell biology into therapeutic advances in Alzheimer's disease. Nature 1999;399:A23-A31.
60.
Godyn J, Jonczyk J, Panek D, Malawska B: Therapeutic strategies for Alzheimer's disease in clinical trials. Pharmacol Rep 2016;68:127-138.
61.
Bram Y, Lampel A, Shaltiel-Karyo R, Ezer A, Scherzer-Attali R, et al: Monitoring and targeting the initial dimerization stage of amyloid self-assembly. Angew Chem Int Ed Engl 2015;54:2062-2067.
62.
Berthoumieu O, Nguyen PH, Castillo-Frias MP, Ferre S, Tarus B, et al: Combined experimental and simulation studies suggest a revised mode of action of the anti-Alzheimer disease drug NQ-Trp. Chemistry 2015;21:12657-12666.
© 2016 S. Karger AG, Basel
2016
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.