1
|
Padhi D, Baruah P, Ramesh M, Moorthy H, Govindaraju T. Hybrid molecules synergistically mitigate ferroptosis and amyloid-associated toxicities in Alzheimer's disease. Redox Biol 2024; 71:103119. [PMID: 38507972 PMCID: PMC10963859 DOI: 10.1016/j.redox.2024.103119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 02/22/2024] [Accepted: 03/07/2024] [Indexed: 03/22/2024] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the build-up of extracellular amyloid β (Aβ) plaques and intracellular neurofibrillary tangles (NFTs). Ferroptosis, an iron (Fe)-dependent form of cell death plays a significant role in the multifaceted AD pathogenesis through generation of reactive oxygen species (ROS), mitochondrial damage, lipid peroxidation, and reduction in glutathione peroxidase 4 (GPX4) enzyme activity and levels. Aberrant liquid-liquid phase separation (LLPS) of tau drives the growth and maturation of NFTs contributing to AD pathogenesis. In this study, we strategically combined the structural and functional properties of gallic acid (GA) and cyclic dipeptides (CDPs) to synthesize hybrid molecules that effectively target both ferroptosis and amyloid toxicity in AD. This innovative approach marks a paradigm shift from conventional therapeutic strategies. This is the first report of a synthetic small molecule (GCTR) that effectively combats ferroptosis, simultaneously restoring enzymatic activity and enhancing cellular levels of its master regulator, GPX4. Further, GCTR disrupts Fe3+-induced LLPS of tau, and aids in attenuation of abnormal tau fibrillization. The synergistic action of GCTR in combating both ferroptosis and amyloid toxicity, bolstered by GPX4 enhancement and modulation of Fe3+-induced tau LLPS, holds promise for the development of small molecule-based novel therapeutics for AD.
Collapse
Affiliation(s)
- Dikshaa Padhi
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, Karnataka, 560064, India
| | - Prayasee Baruah
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, Karnataka, 560064, India
| | - Madhu Ramesh
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, Karnataka, 560064, India
| | - Hariharan Moorthy
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, Karnataka, 560064, India
| | - Thimmaiah Govindaraju
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, Karnataka, 560064, India.
| |
Collapse
|
2
|
Lin H, Sandkuhler S, Dunlea C, Rodwell-Bullock J, King DH, Johnson GVW. BAG3 regulates the specificity of the recognition of specific MAPT species by NBR1 and SQSTM1. Autophagy 2024; 20:577-589. [PMID: 37899687 PMCID: PMC10936643 DOI: 10.1080/15548627.2023.2276622] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 10/19/2023] [Indexed: 10/31/2023] Open
Abstract
Macroautophagy/autophagy receptors are essential for the recognition and clearance of specific cargos by selective autophagy, which is essential for maintaining MAPT proteostasis. Previous studies have implicated different autophagy receptors in directing distinct species of MAPT to autophagy, but the underlying mechanisms have not been fully investigated. Here we examine how the autophagy receptors NBR1 and SQSTM1 differentially associate with specific forms of MAPT. In primary neurons depletion of NBR1, unlike depletion of SQSTM1, significantly increased phosphorylated MAPT levels. The specificity of the interactions was confirmed using in vitro binding assays with purified proteins. We provide direct evidence that the co-chaperone BAG3 promotes the preferential association of NBR1 with monomeric MAPT and SQSTM1 with oligomeric MAPT. Using an in vitro affinity-isolation assay, we show that SQSTM1 only binds to monomeric MAPT when BAG3 is absent and fails to bind when BAG3 is present. The opposite is true of NBR1; its association with monomeric MAPT was dependent on the presence of BAG3. Interestingly, in Alzheimer disease brain the association of NBR1 with BAG3 was significantly decreased. In a mouse model, ablation of BAG3 in neural cells disrupted the association of NBR1 with phosphorylated MAPT and led to increased levels of phosphorylated and oligomeric MAPT. Overall, our results uncover a novel role for BAG3 in regulating the specificity of selective autophagy receptors in targeting different species of MAPT and provide compelling evidence that BAG3 plays a key role in maintaining MAPT proteostasis.Abbreviations: AD: Alzheimer disease; BAG3: BCL2-associated athanogene 3; BSA: bovine serum albumin; CERAD: Consortium to Establish a Registry for Alzheimer's Disease; ESCRT: endosomal sorting complexes required for transport; GST: glutathione S-transferases; MAPT: microtubule-associated protein tau; NBR1: NBR1, autophagy cargo receptor; NFT: neurofibrillary tangles; PMI: postmortem interval; SQSTM1: sequestosome 1.
Collapse
Affiliation(s)
- Heng Lin
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY, USA
| | - Sarah Sandkuhler
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY, USA
| | - Colleen Dunlea
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY, USA
| | - Joel Rodwell-Bullock
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY, USA
| | - Darron H King
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY, USA
| | - Gail V. W. Johnson
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester, NY, USA
| |
Collapse
|
3
|
Ayoub CA, Moore KI, Kuret J. Quantification of Methylation and Phosphorylation Stoichiometry. Methods Mol Biol 2024; 2754:221-235. [PMID: 38512670 DOI: 10.1007/978-1-0716-3629-9_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
Tauopathies including Alzheimer's disease (AD) are neurodegenerative disorders accompanied by the conversion of functional forms of the microtubule associated protein Tau into non-functional aggregates. A variety of post-translational modifications (PTMs) on Tau precede or accompany the conversion, placing them in position to modulate Tau function as well as its propensity to aggregate. Although Tau PTMs can be characterized by their sites of modification, their total stoichiometry when summed over all sites also is an important metric of their potential impact on function. Here we provide a protocol for rapidly producing recombinant Tau with enzyme-specific PTMs at high stoichiometry in vitro and demonstrate its utility in the context of hyperphosphorylation. Additionally, protocols for estimating phosphorylation and methylation stoichiometry on Tau proteins isolated from any source are presented. Together these methods support experimentation on Tau PTM function over a wide range of experimental conditions.
Collapse
Affiliation(s)
- Christopher A Ayoub
- Medical Scientist Training Program, Ohio State University College of Medicine, Columbus, OH, USA
| | - Khadijah I Moore
- Interdisciplinary Biophysics Graduate Program, Ohio State University College of Medicine, Columbus, OH, USA
| | - Jeff Kuret
- Department of Biological Chemistry and Pharmacology, The Ohio State University College of Medicine, Columbus, OH, USA.
| |
Collapse
|
4
|
Malyshka D, Jimenez-Harrison D, Kuret J. Sedimentation and Laser Light Scattering Methods for Quantifying Synthetic Tau Aggregation Propensity. Methods Mol Biol 2024; 2754:117-129. [PMID: 38512664 DOI: 10.1007/978-1-0716-3629-9_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
Tau aggregation assays detect and quantify the conversion of soluble tau monomers into species having filamentous or oligomeric structure. Assays for filamentous aggregates in cross-β-sheet conformation leverage optical, biochemical, or biophysical methods, each with their own advantages and throughput capacity. Here we provide protocols for two medium-throughput assays based on sedimentation and laser light scattering and compare their performance, their utility for characterizing tau aggregation dynamics, and their limitations relative to other approaches. Additionally, a protocol for transmission electron microscopy analysis is updated so as to be compatible with the truncated tau variants that have emerged as powerful tools for interrogating the structural basis of tau polymorphism. Together these methods contribute to a rich tool kit for interrogating tau aggregation kinetics and propensity over a wide range of experimental conditions.
Collapse
Affiliation(s)
- Dmitry Malyshka
- Medical Scientist Training Program, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Daniela Jimenez-Harrison
- Medical Scientist Training Program, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Jeff Kuret
- Department of Biological Chemistry and Pharmacology, The Ohio State University College of Medicine, Columbus, OH, USA.
| |
Collapse
|
5
|
Panzi C, Surana S, De La-Rocque S, Moretto E, Lazo OM, Schiavo G. Botulinum neurotoxin A modulates the axonal release of pathological tau in hippocampal neurons. Toxicon 2023; 228:107110. [PMID: 37037273 PMCID: PMC10636589 DOI: 10.1016/j.toxicon.2023.107110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/03/2023] [Accepted: 04/03/2023] [Indexed: 04/12/2023]
Abstract
Pathological tau aggregates propagate across functionally connected neuronal networks in human neurodegenerative pathologies, such as Alzheimer's disease. However, the mechanism underlying this process is poorly understood. Several studies have showed that tau release is dependent on neuronal activity and that pathological tau is found in the extracellular space in free form, as well as in the lumen of extracellular vesicles. We recently showed that metabotropic glutamate receptor activity and SNAP25 integrity modulate the release of pathological tau from human and mouse synaptosomes. Here, we have leveraged botulinum neurotoxins (BoNTs), which impair neurotransmitter release by cleaving specific synaptic SNARE proteins, to dissect molecular mechanisms related to tau release at synapses. In particular, we have tested the effect of botulinum neurotoxin A (BoNT/A) on the synaptic release of tau in primary mouse neurons. Hippocampal neurons were grown in microfluidic chambers and transduced with lentiviruses expressing human tau (hTau). We found that neuronal stimulation significantly increases the release of mutant hTau, whereas wild-type hTau is unaffected. Importantly, BoNT/A blocks mutant hTau release, indicating that this process is controlled by SNAP25, a component of the SNARE complex, in intact neurons. These results suggest that BoNTs are potent tools to study the spreading of pathological proteins in neurodegenerative diseases and could play a central role in identifying novel molecular targets for the development of therapeutic interventions to treat tauopathies.
Collapse
Affiliation(s)
- Chiara Panzi
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK; UK Dementia Research Institute, University College London, London, UK; UCL Queen Square Motor Neuron Disease Centre, University College London, London, UK.
| | - Sunaina Surana
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK; UK Dementia Research Institute, University College London, London, UK; UCL Queen Square Motor Neuron Disease Centre, University College London, London, UK
| | - Samantha De La-Rocque
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK; UK Dementia Research Institute, University College London, London, UK
| | - Edoardo Moretto
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK; UK Dementia Research Institute, University College London, London, UK; Institute of Neuroscience, CNR, 20854, Vedano al Lambro, Italy
| | - Oscar Marcelo Lazo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK; UK Dementia Research Institute, University College London, London, UK; UCL Queen Square Motor Neuron Disease Centre, University College London, London, UK
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK; UK Dementia Research Institute, University College London, London, UK; UCL Queen Square Motor Neuron Disease Centre, University College London, London, UK.
| |
Collapse
|
6
|
Gerez JA, Prymaczok NC, Kadavath H, Ghosh D, Bütikofer M, Fleischmann Y, Güntert P, Riek R. Protein structure determination in human cells by in-cell NMR and a reporter system to optimize protein delivery or transexpression. Commun Biol 2022; 5:1322. [PMID: 36460747 PMCID: PMC9718737 DOI: 10.1038/s42003-022-04251-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 11/11/2022] [Indexed: 12/03/2022] Open
Abstract
Most experimental methods for structural biology proceed in vitro and therefore the contribution of the intracellular environment on protein structure and dynamics is absent. Studying proteins at atomic resolution in living mammalian cells has been elusive due to the lack of methodologies. In-cell nuclear magnetic resonance spectroscopy (in-cell NMR) is an emerging technique with the power to do so. Here, we improved current methods of in-cell NMR by the development of a reporter system that allows monitoring the delivery of exogenous proteins into mammalian cells, a process that we called here "transexpression". The reporter system was used to develop an efficient protocol for in-cell NMR which enables spectral acquisition with higher quality for both disordered and folded proteins. With this method, the 3D atomic resolution structure of the model protein GB1 in human cells was determined with a backbone root-mean-square deviation (RMSD) of 1.1 Å.
Collapse
Affiliation(s)
- Juan A Gerez
- Laboratory of Physical Chemistry, ETH Zürich, 8093, Zürich, Switzerland.
| | | | | | - Dhiman Ghosh
- Laboratory of Physical Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | | | | | - Peter Güntert
- Laboratory of Physical Chemistry, ETH Zürich, 8093, Zürich, Switzerland
- Institute of Biophysical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt am Main, Germany
- Department of Chemistry, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, 192-0397, Tokyo, Japan
| | - Roland Riek
- Laboratory of Physical Chemistry, ETH Zürich, 8093, Zürich, Switzerland.
| |
Collapse
|
7
|
Molecular mechanism for the synchronized electrostatic coacervation and co-aggregation of alpha-synuclein and tau. Nat Commun 2022; 13:4586. [PMID: 35933508 PMCID: PMC9357037 DOI: 10.1038/s41467-022-32350-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 07/26/2022] [Indexed: 01/05/2023] Open
Abstract
Amyloid aggregation of α-synuclein (αS) is the hallmark of Parkinson’s disease and other synucleinopathies. Recently, Tau protein, generally associated with Alzheimer’s disease, has been linked to αS pathology and observed to co-localize in αS-rich disease inclusions, although the molecular mechanisms for the co-aggregation of both proteins remain elusive. We report here that αS phase-separates into liquid condensates by electrostatic complex coacervation with positively charged polypeptides such as Tau. Condensates undergo either fast gelation or coalescence followed by slow amyloid aggregation depending on the affinity of αS for the poly-cation and the rate of valence exhaustion of the condensate network. By combining a set of advanced biophysical techniques, we have been able to characterize αS/Tau liquid-liquid phase separation and identified key factors that lead to the formation of hetero-aggregates containing both proteins in the interior of the liquid protein condensates. Here, the authors report that α-synuclein phase-separates into liquid condensates with positively charged polypeptides such as Tau. The condensates undergo different maturation processes, including the formation of α-synuclein/Tau amyloid hetero-aggregates inside the condensates.
Collapse
|
8
|
Pesce G, Gondelaud F, Ptchelkine D, Nilsson JF, Bignon C, Cartalas J, Fourquet P, Longhi S. Experimental Evidence of Intrinsic Disorder and Amyloid Formation by the Henipavirus W Proteins. Int J Mol Sci 2022; 23:ijms23020923. [PMID: 35055108 PMCID: PMC8780864 DOI: 10.3390/ijms23020923] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 02/01/2023] Open
Abstract
Henipaviruses are severe human pathogens within the Paramyxoviridae family. Beyond the P protein, the Henipavirus P gene also encodes the V and W proteins which share with P their N-terminal, intrinsically disordered domain (NTD) and possess a unique C-terminal domain. Henipavirus W proteins antagonize interferon (IFN) signaling through NTD-mediated binding to STAT1 and STAT4, and prevent type I IFN expression and production of chemokines. Structural and molecular information on Henipavirus W proteins is lacking. By combining various bioinformatic approaches, we herein show that the Henipaviruses W proteins are predicted to be prevalently disordered and yet to contain short order-prone segments. Using limited proteolysis, differential scanning fluorimetry, analytical size exclusion chromatography, far-UV circular dichroism and small-angle X-ray scattering, we experimentally confirmed their overall disordered nature. In addition, using Congo red and Thioflavin T binding assays and negative-staining transmission electron microscopy, we show that the W proteins phase separate to form amyloid-like fibrils. The present study provides an additional example, among the few reported so far, of a viral protein forming amyloid-like fibrils, therefore significantly contributing to enlarge our currently limited knowledge of viral amyloids. In light of the critical role of the Henipavirus W proteins in evading the host innate immune response and of the functional role of phase separation in biology, these studies provide a conceptual asset to further investigate the functional impact of the phase separation abilities of the W proteins.
Collapse
Affiliation(s)
- Giulia Pesce
- Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Aix Marseille University and Centre National de la Recherche Scientifique (CNRS), 163 Avenue de Luminy, Case 932, 13288 Marseille, France; (G.P.); (F.G.); (D.P.); (J.F.N.); (C.B.); (J.C.)
| | - Frank Gondelaud
- Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Aix Marseille University and Centre National de la Recherche Scientifique (CNRS), 163 Avenue de Luminy, Case 932, 13288 Marseille, France; (G.P.); (F.G.); (D.P.); (J.F.N.); (C.B.); (J.C.)
| | - Denis Ptchelkine
- Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Aix Marseille University and Centre National de la Recherche Scientifique (CNRS), 163 Avenue de Luminy, Case 932, 13288 Marseille, France; (G.P.); (F.G.); (D.P.); (J.F.N.); (C.B.); (J.C.)
| | - Juliet F. Nilsson
- Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Aix Marseille University and Centre National de la Recherche Scientifique (CNRS), 163 Avenue de Luminy, Case 932, 13288 Marseille, France; (G.P.); (F.G.); (D.P.); (J.F.N.); (C.B.); (J.C.)
| | - Christophe Bignon
- Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Aix Marseille University and Centre National de la Recherche Scientifique (CNRS), 163 Avenue de Luminy, Case 932, 13288 Marseille, France; (G.P.); (F.G.); (D.P.); (J.F.N.); (C.B.); (J.C.)
| | - Jérémy Cartalas
- Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Aix Marseille University and Centre National de la Recherche Scientifique (CNRS), 163 Avenue de Luminy, Case 932, 13288 Marseille, France; (G.P.); (F.G.); (D.P.); (J.F.N.); (C.B.); (J.C.)
| | - Patrick Fourquet
- INSERM, Centre de Recherche en Cancérologie de Marseille (CRCM), Centre National de la Recherche Scientifique (CNRS), Marseille Protéomique, Institut Paoli-Calmettes, Aix Marseille University, 27 Bvd Leï Roure, CS 30059, 13273 Marseille, France;
| | - Sonia Longhi
- Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Aix Marseille University and Centre National de la Recherche Scientifique (CNRS), 163 Avenue de Luminy, Case 932, 13288 Marseille, France; (G.P.); (F.G.); (D.P.); (J.F.N.); (C.B.); (J.C.)
- Correspondence:
| |
Collapse
|
9
|
The Anti-Inflammatory Protein TNIP1 Is Intrinsically Disordered with Structural Flexibility Contributed by Its AHD1-UBAN Domain. Biomolecules 2020; 10:biom10111531. [PMID: 33182596 PMCID: PMC7697625 DOI: 10.3390/biom10111531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/04/2020] [Accepted: 11/05/2020] [Indexed: 01/02/2023] Open
Abstract
TNFAIP3 interacting protein 1 (TNIP1) interacts with numerous non-related cellular, viral, and bacterial proteins. TNIP1 is also linked with multiple chronic inflammatory disorders on the gene and protein levels, through numerous single-nucleotide polymorphisms and reduced protein amounts. Despite the importance of TNIP1 function, there is limited investigation as to how its conformation may impact its apparent multiple roles. Hub proteins like TNIP1 are often intrinsically disordered proteins. Our initial in silico assessments suggested TNIP1 is natively unstructured, featuring numerous potentials intrinsically disordered regions, including the ABIN homology domain 1-ubiquitin binding domain in ABIN proteins and NEMO (AHD1-UBAN) domain associated with its anti-inflammatory function. Using multiple biophysical approaches, we demonstrate the structural flexibility of full-length TNIP1 and the AHD1-UBAN domain. We present evidence the AHD1-UBAN domain exists primarily as a pre-molten globule with limited secondary structure in solution. Data presented here suggest the previously described coiled-coil conformation of the crystallized UBAN-only region may represent just one of possibly multiple states for the AHD1-UBAN domain in solution. These data also characterize the AHD1-UBAN domain in solution as mostly monomeric with potential to undergo oligomerization under specific environmental conditions (e.g., binding partner availability, pH-dependence). This proposed intrinsic disorder across TNIP1 and within the AHD1-UBAN region is likely to impact TNIP1 function and interaction with its multiple partners.
Collapse
|
10
|
Viswanathan GK, Shwartz D, Losev Y, Arad E, Shemesh C, Pichinuk E, Engel H, Raveh A, Jelinek R, Cooper I, Gosselet F, Gazit E, Segal D. Purpurin modulates Tau-derived VQIVYK fibrillization and ameliorates Alzheimer's disease-like symptoms in animal model. Cell Mol Life Sci 2020; 77:2795-2813. [PMID: 31562564 PMCID: PMC11104911 DOI: 10.1007/s00018-019-03312-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 08/11/2019] [Accepted: 09/19/2019] [Indexed: 01/20/2023]
Abstract
Neurofibrillary tangles of the Tau protein and plaques of the amyloid β peptide are hallmarks of Alzheimer's disease (AD), which is characterized by the conversion of monomeric proteins/peptides into misfolded β-sheet rich fibrils. Halting the fibrillation process and disrupting the existing aggregates are key challenges for AD drug development. Previously, we performed in vitro high-throughput screening for the identification of potent inhibitors of Tau aggregation using a proxy model, a highly aggregation-prone hexapeptide fragment 306VQIVYK311 (termed PHF6) derived from Tau. Here we have characterized a hit molecule from that screen as a modulator of Tau aggregation using in vitro, in silico, and in vivo techniques. This molecule, an anthraquinone derivative named Purpurin, inhibited ~ 50% of PHF6 fibrillization in vitro at equimolar concentration and disassembled pre-formed PHF6 fibrils. In silico studies showed that Purpurin interacted with key residues of PHF6, which are responsible for maintaining its β-sheets conformation. Isothermal titration calorimetry and surface plasmon resonance experiments with PHF6 and full-length Tau (FL-Tau), respectively, indicated that Purpurin interacted with PHF6 predominantly via hydrophobic contacts and displayed a dose-dependent complexation with FL-Tau. Purpurin was non-toxic when fed to Drosophila and it significantly ameliorated the AD-related neurotoxic symptoms of transgenic flies expressing WT-FL human Tau (hTau) plausibly by inhibiting Tau accumulation and reducing Tau phosphorylation. Purpurin also reduced hTau accumulation in cell culture overexpressing hTau. Importantly, Purpurin efficiently crossed an in vitro human blood-brain barrier model. Our findings suggest that Purpurin could be a potential lead molecule for AD therapeutics.
Collapse
Affiliation(s)
- Guru Krishnakumar Viswanathan
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, Tel-Aviv University, 69978, Tel Aviv, Israel
| | - Dana Shwartz
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, Tel-Aviv University, 69978, Tel Aviv, Israel
| | - Yelena Losev
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, Tel-Aviv University, 69978, Tel Aviv, Israel
| | - Elad Arad
- Ilse Katz Institute (IKI) for Nanoscale Science and Technology, Ben Gurion University of the Negev, 8410501, Beer Sheva, Israel
- Department of Chemistry, Ben Gurion University of the Negev, 8410501, Beer Sheva, Israel
| | - Chen Shemesh
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, 52621, Ramat Gan, Israel
| | - Edward Pichinuk
- Blavatnik Center for Drug Discovery, Tel-Aviv University, 69978, Tel Aviv, Israel
| | - Hamutal Engel
- Blavatnik Center for Drug Discovery, Tel-Aviv University, 69978, Tel Aviv, Israel
| | - Avi Raveh
- Blavatnik Center for Drug Discovery, Tel-Aviv University, 69978, Tel Aviv, Israel
| | - Raz Jelinek
- Ilse Katz Institute (IKI) for Nanoscale Science and Technology, Ben Gurion University of the Negev, 8410501, Beer Sheva, Israel
- Department of Chemistry, Ben Gurion University of the Negev, 8410501, Beer Sheva, Israel
| | - Itzik Cooper
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, 52621, Ramat Gan, Israel
- Interdisciplinary Center Herzliya, Herzliya, Israel
| | - Fabien Gosselet
- Blood-Brain Barrier Laboratory (LBHE), Université d'Artois, Lens, France
| | - Ehud Gazit
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, Tel-Aviv University, 69978, Tel Aviv, Israel
- Blavatnik Center for Drug Discovery, Tel-Aviv University, 69978, Tel Aviv, Israel
| | - Daniel Segal
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, Tel-Aviv University, 69978, Tel Aviv, Israel.
- The Interdisciplinary Sagol School of Neurosciences, Tel-Aviv University, 69978, Tel Aviv, Israel.
| |
Collapse
|
11
|
Banerjee S, Ferdosh S, Ghosh AN, Barat C. Tau protein- induced sequestration of the eukaryotic ribosome: Implications in neurodegenerative disease. Sci Rep 2020; 10:5225. [PMID: 32251304 PMCID: PMC7090008 DOI: 10.1038/s41598-020-61777-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 02/28/2020] [Indexed: 12/15/2022] Open
Abstract
The human tau is a microtubule-associated intrinsically unstructured protein that forms intraneuronal cytotoxic deposits in neurodegenerative diseases, like tauopathies. Recent studies indicate that in Alzheimer's disease, ribosomal dysfunction might be a crucial event in the disease pathology. Our earlier studies had demonstrated that amorphous protein aggregation in the presence of ribosome can lead to sequestration of the ribosomal components. The present study aims at determining the effect of incubation of the full-length tau protein (Ht40) and its microtubule binding 4-repeat domain (K18) on the eukaryotic ribosome. Our in vitro studies show that incubation of Ht40 and the K18 tau variants with isolated non-translating yeast ribosome can induce a loss of ribosome physical integrity resulting in formation of tau-rRNA-ribosomal protein aggregates. Incubation with the tau protein variants also led to a disappearance of the peak indicating the ribosome profile of the HeLa cell lysate and suppression of translation in the human in vitro translation system. The incubation of tau protein with the ribosomal RNA leads to the formation of tau-rRNA aggregates. The effect of K18 on the yeast ribosome can be mitigated in the presence of cellular polyanions like heparin and tRNA, thereby indicating the electrostatic nature of the aggregation process.
Collapse
Affiliation(s)
- Senjuti Banerjee
- Department of Biotechnology, St. Xavier's College, Park Street, Kolkata, 700016, West Bengal, India
| | - Sehnaz Ferdosh
- Department of Biotechnology, St. Xavier's College, Park Street, Kolkata, 700016, West Bengal, India
| | - Amar Nath Ghosh
- National Institute of Cholera and Enteric Diseases P-33, C.I.T. Road, Scheme XM, Beleghata, India
| | - Chandana Barat
- Department of Biotechnology, St. Xavier's College, Park Street, Kolkata, 700016, West Bengal, India.
| |
Collapse
|
12
|
Jia L, Zhao W, Wei W, Guo X, Wang W, Wang Y, Sang J, Lu F, Liu F. Expression and purification of amyloid β-protein, tau, and α-synuclein in Escherichia coli: a review. Crit Rev Biotechnol 2020; 40:475-489. [PMID: 32202164 DOI: 10.1080/07388551.2020.1742646] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Misfolding and accumulation of amyloidogenic proteins into various forms of aggregated intermediates and insoluble amyloid fibrils is associated with more than 50 human diseases. Large amounts of high-quality amyloid proteins are required for better probing of their aggregation and neurotoxicity. Due to their intrinsic hydrophobicity, it is a challenge to obtain amyloid proteins with high yield and purity, and they have attracted the attention of researchers from all over the world. The rapid development of bioengineering technology provides technical support for obtaining large amounts of recombinant amyloidogenic proteins. This review discusses the available expression and purification methods for three amyloid proteins including amyloid β-protein, tau, and α-synuclein in microbial expression systems, especially Escherichia coli, and discusses the advantages and disadvantages of these methods. Importantly, these protocols can also be referred to for the expression and purification of other hydrophobic proteins.
Collapse
Affiliation(s)
- Longgang Jia
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China.,College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin, China
| | - Wenping Zhao
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Wei Wei
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Xiao Guo
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Wenjuan Wang
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Ying Wang
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Jingcheng Sang
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Fuping Lu
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Fufeng Liu
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| |
Collapse
|
13
|
Kumar S, Krishnakumar VG, Morya V, Gupta S, Datta B. Nanobiocatalyst facilitated aglycosidic quercetin as a potent inhibitor of tau protein aggregation. Int J Biol Macromol 2019; 138:168-180. [DOI: 10.1016/j.ijbiomac.2019.07.081] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/09/2019] [Accepted: 07/11/2019] [Indexed: 12/21/2022]
|
14
|
Ferrari L, Rüdiger SGD. Recombinant production and purification of the human protein Tau. Protein Eng Des Sel 2019; 31:447-455. [PMID: 31265107 DOI: 10.1093/protein/gzz010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/28/2019] [Accepted: 05/29/2019] [Indexed: 11/13/2022] Open
Abstract
Tau protein is a microtubule-stabilising protein whose aggregation is linked to Alzheimer's Disease and other forms of dementia. Tau biology is at the heart of cytoskeletal dynamics and neurodegenerative mechanisms, making it a crucial protein to study. Tau purification, however, is challenging as Tau is disordered, which makes it difficult to produce in recombinant system and is degradation-prone. It is thus challenging to obtain pure and stable preparations of Tau. Here, we present a fast and robust protocol to purify Tau recombinantly in Escherichia coli. Our protocol allows purifying Tau either tag-less or FLAG-tagged at its N-terminus, and Tau fragments of interest. By exploiting a cleavable affinity tag and two anion exchange columns, we obtained Tau preparations of high purity, stable and suitable for in vitro studies, including aggregation experiments that resemble neurodegenerative processes.
Collapse
Affiliation(s)
- Luca Ferrari
- Cellular Protein Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, Utrecht, The Netherlands.,Science for Life, Utrecht University, Padualaan 8, Utrecht, The Netherlands
| | - Stefan G D Rüdiger
- Cellular Protein Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, Utrecht, The Netherlands.,Science for Life, Utrecht University, Padualaan 8, Utrecht, The Netherlands
| |
Collapse
|
15
|
Siano G, Caiazza MC, Ollà I, Varisco M, Madaro G, Quercioli V, Calvello M, Cattaneo A, Di Primio C. Identification of an ERK Inhibitor as a Therapeutic Drug Against Tau Aggregation in a New Cell-Based Assay. Front Cell Neurosci 2019; 13:386. [PMID: 31496937 PMCID: PMC6712076 DOI: 10.3389/fncel.2019.00386] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 08/06/2019] [Indexed: 01/01/2023] Open
Abstract
Formation of Tau aggregates is a common pathological feature of tauopathies and their accumulation directly correlates with cytotoxicity and neuronal degeneration. Great efforts have been made to understand Tau aggregation and to find therapeutics halting or reversing the process, however, progress has been slowed due to the lack of a suitable method for monitoring Tau aggregation. We developed a cell-based assay allowing to detect and quantify Tau aggregation in living cells. The system is based on the FRET biosensor CST able to monitor the molecular dynamic of Tau aggregation in different cellular conditions. We probed candidate compounds that could block Tau hyperphosphorylation. In particular, to foster the drug discovery process, we tested kinase inhibitors approved for the treatment of other diseases. We identified the ERK inhibitor PD-901 as a promising therapeutic molecule since it reduces and prevents Tau aggregation. This evidence establishes the CST cell-based aggregation assay as a reliable tool for drug discovery and suggests that PD-901 might be a promising compound to be tested for further preclinical studies on AD.
Collapse
Affiliation(s)
- Giacomo Siano
- Laboratorio di Biologia (BIO@SNS), Scuola Normale Superiore, Pisa, Italy
| | | | - Ivana Ollà
- Laboratorio di Biologia (BIO@SNS), Scuola Normale Superiore, Pisa, Italy
| | - Martina Varisco
- Laboratorio di Biologia (BIO@SNS), Scuola Normale Superiore, Pisa, Italy
| | - Giuseppe Madaro
- Laboratorio di Biologia (BIO@SNS), Scuola Normale Superiore, Pisa, Italy
| | | | | | - Antonino Cattaneo
- Laboratorio di Biologia (BIO@SNS), Scuola Normale Superiore, Pisa, Italy.,Neurotrophins and Neurodegenerative Diseases Laboratory, Rita Levi-Montalcini European Brain Research Institute, Rome, Italy
| | - Cristina Di Primio
- Laboratorio di Biologia (BIO@SNS), Scuola Normale Superiore, Pisa, Italy
| |
Collapse
|
16
|
Graether SP. Troubleshooting Guide to Expressing Intrinsically Disordered Proteins for Use in NMR Experiments. Front Mol Biosci 2019; 5:118. [PMID: 30713842 PMCID: PMC6345686 DOI: 10.3389/fmolb.2018.00118] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 12/23/2018] [Indexed: 12/17/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) represent a structural class of proteins that do not have a well-defined, 3D fold in solution, and often have little secondary structure. To characterize their function and molecular mechanism, it is helpful to examine their structure using nuclear magnetic resonance (NMR), which can report on properties, such as residual structure (at both the secondary and tertiary levels), ligand binding affinity, and the effect of ligand binding on IDP structure, all on a per residue basis. This brief review reports on the common problems and decisions that are involved when preparing a disordered protein for NMR studies. The paper covers gene design, expression host choice, protein purification, and the initial NMR experiments that are performed. While many of these steps are essentially identical to those for ordered proteins, a few key differences are highlighted, including the extreme sensitivity of IDPs to proteolytic cleavage, the ability to use denaturing conditions without having to refold the protein, the optimal chromatographic system choice, and the challenges of quantifying an IDP. After successful purification, characterization by NMR can be done using the standard 15N-heteronuclear single quantum coherence (15N-HSQC) experiment, or the newer CON series of experiments that are superior for disordered proteins.
Collapse
Affiliation(s)
- Steffen P Graether
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| |
Collapse
|
17
|
Carbamylation promotes amyloidogenesis and induces structural changes in Tau-core hexapeptide fibrils. Biochim Biophys Acta Gen Subj 2018; 1862:2590-2604. [PMID: 30071272 DOI: 10.1016/j.bbagen.2018.07.030] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 07/10/2018] [Accepted: 07/26/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND Carbamylation is a non-enzymatic post-translational modification (PTM), which involves the covalent modification of N-terminus of protein or ε-amino group of Lys. The role of carbamylation in several age-related disorders is well documented, however, the relationship between carbamylation and neurodegenerative disorders including Alzheimer's disease remains uncharted. METHODS In the present study, using aggregation-prone tau-core hexapeptide fragments 306VQIVYK311 (PHF6) and 275VQIINK280 (PHF6*) as models, we have elucidated the effect of carbamylation on aggregation kinetics and the changes occurring in the 3-dimensional architecture of fibrils using biophysical assays and molecular dynamics simulations. RESULTS We found that carbamylation aids in amyloid formation and can convert the unstructured off-pathway aggregates into robust amyloids, which were toxic to cells. Electron microscopy images and molecular dynamics simulations of PHF6 fibrils showed that carbamylated peptides can form excess hydrogen bonds and modulate the pitch length and twist of peptides fibrils. We have also compared N-terminal carbamylation to acetylation and further extended our finding to full length tau that exhibits aggregation upon carbamylation even in the absence of any external inducer. CONCLUSION Our in vitro and in silico results together suggest that carbamylation can modulate the aggregation pathway of the amyloidegenic sequences and cause structural changes in fibril assemblies. GENERAL SIGNIFICANCE Carbamylation acts as a switch, which triggers the aggregation in short amyloidogenic peptide fragments and modulate the structural changes in resulting amyloid fibrils.
Collapse
|
18
|
Haj E, Losev Y, Guru KrishnaKumar V, Pichinuk E, Engel H, Raveh A, Gazit E, Segal D. Integrating in vitro and in silico approaches to evaluate the "dual functionality" of palmatine chloride in inhibiting and disassembling Tau-derived VQIVYK peptide fibrils. Biochim Biophys Acta Gen Subj 2018; 1862:1565-1575. [PMID: 29634991 DOI: 10.1016/j.bbagen.2018.04.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 03/20/2018] [Accepted: 04/03/2018] [Indexed: 01/02/2023]
Abstract
BACKGROUND Alzheimer's disease (AD) is the most common neurodegenerative disorder which is characterized by the deposits of intra-cellular tau protein and extra-cellular amyloid-β (Aβ) peptides in the human brain. Understanding the mechanism of protein aggregation and finding compounds that are capable of inhibiting its aggregation is considered to be highly important for disease therapy. METHODS We used an in vitro High-Throughput Screening for the identification of potent inhibitors of tau aggregation using a proxy model; a highly aggregation-prone hexapeptide fragment 306VQIVYK311 derived from tau. Using ThS fluorescence assay we screened a library of 2401 FDA approved, bio-active and natural compounds in attempt to find molecules which can efficiently modulate tau aggregation. RESULTS Among the screened compounds, palmatine chloride (PC) alkaloid was able to dramatically reduce the aggregation propensity of PHF6 at sub-molar concentrations. PC was also able to disassemble preformed aggregates of PHF6 and reduce the amyloid content in a dose-dependent manner. Insights obtained from MD simulation showed that PC interacted with the key residues of PHF6 responsible for β-sheet formation, which could likely be the mechanism of inhibition and disassembly. Furthermore, PC could effectively inhibit the aggregation of full-length tau and disassemble preformed aggregates. CONCLUSIONS We found that PC possesses "dual functionality" towards PHF6 and full-length tau, i.e. inhibit their aggregation and disassemble pre-formed fibrils. GENERAL SIGNIFICANCE The "dual functionality" of PC is valuable as a disease modifying strategy for AD, and other tauopathies, by inhibiting their progress and reducing the effect of fibrils already present in the brain.
Collapse
Affiliation(s)
- Esraa Haj
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Yelena Losev
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv 69978, Israel
| | - V Guru KrishnaKumar
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv 69978, Israel; Department of Biological Engineering, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, Gujarat 382355, India
| | - Edward Pichinuk
- BLAVATNIK CENTER for Drug Discovery, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Hamutal Engel
- BLAVATNIK CENTER for Drug Discovery, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Avi Raveh
- BLAVATNIK CENTER for Drug Discovery, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Ehud Gazit
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv 69978, Israel; BLAVATNIK CENTER for Drug Discovery, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Daniel Segal
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv 69978, Israel; The Interdisciplinary Sagol School of Neurosciences, Tel-Aviv University, Tel Aviv 69978, Israel.
| |
Collapse
|
19
|
Mechanistic insights into remodeled Tau-derived PHF6 peptide fibrils by Naphthoquinone-Tryptophan hybrids. Sci Rep 2018; 8:71. [PMID: 29311706 PMCID: PMC5758761 DOI: 10.1038/s41598-017-18443-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 12/12/2017] [Indexed: 11/20/2022] Open
Abstract
Intra-cellular tau protein tangles and extra-cellular β-amyloid plaques are hallmarks of Alzheimer’s disease (AD), characterized by the conversion of natively unfolded monomeric protein/peptide into misfolded β-sheet rich aggregates. Therefore, inhibiting the aggregation cascade or disassembling the pre-formed aggregates becomes a pivotal event in disease treatment. In the present study, we show that Naphthoquinone-Tryptophan hybrids, i.e., NQTrp and Cl-NQTrp significantly disrupted the pre-formed fibrillar aggregates of Tau-derived PHF6 (VQIVYK) peptide and full-length tau protein in vitro, in a dose-dependent manner as evident from ThS assay, CD spectroscopy, and TEM. Molecular dynamics simulation of PHF6 oligomers and fibrils with the Naphthoquinone-Tryptophan hybrids provides a possible structure-function based mechanism-of-action, highlighting the role of hydrophobic interaction and hydrogen bond formation during fibril disassembly. These findings signify the effectiveness of NQTrp and Cl-NQTrp in disassembling fibrillar aggregates and may help in designing novel hybrid molecules for AD treatment.
Collapse
|