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Markaki M, Tavernarakis N. Caenorhabditis elegans as a model system for human diseases. Curr Opin Biotechnol 2020; 63:118-125. [PMID: 31951916 DOI: 10.1016/j.copbio.2019.12.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 12/08/2019] [Accepted: 12/11/2019] [Indexed: 01/23/2023]
Abstract
The nematode Caenorhabditis elegans offers unique advantages that enable a comprehensive delineation of the cellular and molecular mechanisms underlying devastating human pathologies such as stroke, ischemia and age-associated neurodegenerative disorders. Genetic models of human diseases that closely simulate several disease-related phenotypes have been established in the worm. These models allow the implementation of multidisciplinary approaches, in addition to large-scale genetic and pharmacological screenings, designed to elucidate the molecular mechanisms mediating pathogenesis and to identify targets and drugs for emergent therapeutic interventions. Such strategies have already provided valuable insights, highly relevant to human health and quality of life. This article considers the potential of C. elegans as a versatile platform for systematic dissection of the molecular basis of human disease, focusing on neurodegenerative disorders.
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Affiliation(s)
- Maria Markaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion 70013, Crete, Greece
| | - Nektarios Tavernarakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion 70013, Crete, Greece; Department of Basic Sciences, School of Medicine, University of Crete, Heraklion 70013, Crete, Greece.
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52
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Ashkavand Z, Sarasija S, Ryan KC, Laboy JT, Norman KR. Corrupted ER-mitochondrial calcium homeostasis promotes the collapse of proteostasis. Aging Cell 2020; 19:e13065. [PMID: 31714672 PMCID: PMC6974732 DOI: 10.1111/acel.13065] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 09/30/2019] [Accepted: 10/17/2019] [Indexed: 11/28/2022] Open
Abstract
Aging and age-related diseases are associated with a decline of protein homeostasis (proteostasis), but the mechanisms underlying this decline are not clear. In particular, decreased proteostasis is a widespread molecular feature of neurodegenerative diseases, such as Alzheimer's disease (AD). Familial AD is largely caused by mutations in the presenilin encoding genes; however, their role in AD is not understood. In this study, we investigate the role of presenilins in proteostasis using the model system Caenorhabditis elegans. Previously, we found that mutations in C. elegans presenilin cause elevated ER to mitochondria calcium signaling, which leads to an increase in mitochondrial generated oxidative stress. This, in turn, promotes neurodegeneration. To understand the cellular mechanisms driving neurodegeneration, using several molecular readouts of protein stability in C. elegans, we find that presenilin mutants have widespread defects in proteostasis. Markedly, we demonstrate that these defects are independent of the protease activity of presenilin and that reduction in ER to mitochondrial calcium signaling can significantly prevent the proteostasis defects observed in presenilin mutants. Furthermore, we show that supplementing presenilin mutants with antioxidants suppresses the proteostasis defects. Our findings indicate that defective ER to mitochondria calcium signaling promotes proteostatic collapse in presenilin mutants by increasing oxidative stress.
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Affiliation(s)
- Zahra Ashkavand
- Department of Regenerative and Cancer Cell BiologyAlbany Medical CollegeAlbanyNYUSA
| | - Shaarika Sarasija
- Department of Regenerative and Cancer Cell BiologyAlbany Medical CollegeAlbanyNYUSA
| | - Kerry C. Ryan
- Department of Regenerative and Cancer Cell BiologyAlbany Medical CollegeAlbanyNYUSA
| | - Jocelyn T. Laboy
- Department of Regenerative and Cancer Cell BiologyAlbany Medical CollegeAlbanyNYUSA
| | - Kenneth R. Norman
- Department of Regenerative and Cancer Cell BiologyAlbany Medical CollegeAlbanyNYUSA
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53
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Chen X, Jiang H. Tau as a potential therapeutic target for ischemic stroke. Aging (Albany NY) 2019; 11:12827-12843. [PMID: 31841442 PMCID: PMC6949092 DOI: 10.18632/aging.102547] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 11/19/2019] [Indexed: 12/12/2022]
Abstract
Tau is a protein mainly expressed in adult human brain. It plays important roles both in neurodegenerative diseases and stroke. Stroke is an important cause of adult death and disability, ischemic stroke almost account for 80% in all cases. Abundant studies have proven that the increase of dysfunctional tau may act as a vital factor in pathological changes after ischemic stroke. However, the relationship between tau and ischemic stroke remains ununified. Based on present studies, we firstly introduced the structure and biological function of tau protein. Secondly, we summarized the potential regulatory mechanisms of tau protein in the process of ischemic stroke. Thirdly, we discussed about the findings in therapeutic researches of ischemic stroke. This review may be helpful in implementing new therapies for ischemic stroke and may be beneficial for the clinical and experimental studies.
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Affiliation(s)
- Xin Chen
- Department of Geriatrics, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Hua Jiang
- Department of Geriatrics, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
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54
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Swim exercise in Caenorhabditis elegans extends neuromuscular and gut healthspan, enhances learning ability, and protects against neurodegeneration. Proc Natl Acad Sci U S A 2019; 116:23829-23839. [PMID: 31685639 PMCID: PMC6876156 DOI: 10.1073/pnas.1909210116] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Exercise is a powerful antiaging intervention that protects against cardiovascular disease, dementia, diabetes, sarcopenia, and cancer. How exercise promotes health benefits to multiple tissues in the body, however, remains poorly understood. We establish a young adult swim exercise regimen for the short-lived nematode Caenorhabditis elegans that induces health benefits at the neuromuscular, intestinal, and cognitive levels and protects against neurodegeneration in models of tauopathy, Alzheimer’s disease, and Huntington’s disease. Importantly, we found that swim exercise performed exclusively in early adulthood promotes long-lasting systemic benefits that are still detectable in midlife. The advantages of C. elegans as a short-lived genetic model will allow for dissection of the molecular circuitry involved in system-wide exercise benefits. Regular physical exercise is the most efficient and accessible intervention known to promote healthy aging in humans. The molecular and cellular mechanisms that mediate system-wide exercise benefits, however, remain poorly understood, especially as applies to tissues that do not participate directly in training activity. The establishment of exercise protocols for short-lived genetic models will be critical for deciphering fundamental mechanisms of transtissue exercise benefits to healthy aging. Here we document optimization of a long-term swim exercise protocol for Caenorhabditis elegans and we demonstrate its benefits to diverse aging tissues, even if exercise occurs only during a restricted phase of adulthood. We found that multiple daily swim sessions are essential for exercise adaptation, leading to body wall muscle improvements in structural gene expression, locomotory performance, and mitochondrial morphology. Swim exercise training enhances whole-animal health parameters, such as mitochondrial respiration and midlife survival, increases functional healthspan of the pharynx and intestine, and enhances nervous system health by increasing learning ability and protecting against neurodegeneration in models of tauopathy, Alzheimer’s disease, and Huntington’s disease. Remarkably, swim training only during early adulthood induces long-lasting systemic benefits that in several cases are still detectable well into midlife. Our data reveal the broad impact of swim exercise in promoting extended healthspan of multiple C. elegans tissues, underscore the potency of early exercise experience to influence long-term health, and establish the foundation for exploiting the powerful advantages of this genetic model for the dissection of the exercise-dependent molecular circuitry that confers system-wide health benefits to aging adults.
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Hydralazine targets cAMP-dependent protein kinase leading to sirtuin1/5 activation and lifespan extension in C. elegans. Nat Commun 2019; 10:4905. [PMID: 31659167 PMCID: PMC6817882 DOI: 10.1038/s41467-019-12425-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 08/14/2019] [Indexed: 12/22/2022] Open
Abstract
Therapeutic activation of mitochondrial function has been suggested as an effective strategy to combat aging. Hydralazine is an FDA-approved drug used in the treatment of hypertension, heart failure and cancer. Hydralazine has been recently shown to promote lifespan in C. elegans, rotifer and yeast through a mechanism which has remained elusive. Here we report cAMP-dependent protein kinase (PKA) as the direct target of hydralazine. Using in vitro and in vivo models, we demonstrate a mechanism in which binding and stabilization of a catalytic subunit of PKA by hydralazine lead to improved mitochondrial function and metabolic homeostasis via the SIRT1/SIRT5 axis, which underlies hydralazine's prolongevity and stress resistance benefits. Hydralazine also protects mitochondrial metabolism and function resulting in restoration of health and lifespan in C. elegans under high glucose and other stress conditions. Our data also provide new insights into the mechanism(s) that explain various other known beneficial effects of hydralazine.
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57
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Mattedi F, Vagnoni A. Temporal Control of Axonal Transport: The Extreme Case of Organismal Ageing. Front Cell Neurosci 2019; 13:393. [PMID: 31555095 PMCID: PMC6716446 DOI: 10.3389/fncel.2019.00393] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 08/09/2019] [Indexed: 01/05/2023] Open
Abstract
A fundamental question in cell biology is how cellular components are delivered to their destination with spatial and temporal precision within the crowded cytoplasmic environment. The long processes of neurons represent a significant spatial challenge and make these cells particularly dependent on mechanisms for long-range cytoskeletal transport of proteins, RNA and organelles. Although many studies have substantiated a role for defective transport of axonal cargoes in the pathogenesis of neurodevelopmental and neurodegenerative diseases, remarkably little is known about how transport is regulated throughout ageing. The scale of the challenge posed by ageing is considerable because, in this case, the temporal regulation of transport is ultimately dictated by the length of organismal lifespan, which can extend to days, years or decades. Recent methodological advances to study live axonal transport during ageing in situ have provided new tools to scratch beneath the surface of this complex problem and revealed that age-dependent decline in the transport of mitochondria is a common feature across different neuronal populations of several model organisms. In certain instances, the molecular pathways that affect transport in ageing animals have begun to emerge. However, the functional implications of these observations are still not fully understood. Whether transport decline is a significant determinant of neuronal ageing or a mere consequence of decreased cellular fitness remains an open question. In this review, we discuss the latest developments in axonal trafficking in the ageing nervous system, along with the early studies that inaugurated this new area of research. We explore the possibility that the interplay between mitochondrial function and motility represents a crucial driver of ageing in neurons and put forward the hypothesis that declining axonal transport may be legitimately considered a hallmark of neuronal ageing.
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Affiliation(s)
| | - Alessio Vagnoni
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, IoPPN, King’s College London, London, United Kingdom
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58
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Schweig JE, Yao H, Coppola K, Jin C, Crawford F, Mullan M, Paris D. Spleen tyrosine kinase (SYK) blocks autophagic Tau degradation in vitro and in vivo. J Biol Chem 2019; 294:13378-13395. [PMID: 31324720 DOI: 10.1074/jbc.ra119.008033] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 07/12/2019] [Indexed: 12/29/2022] Open
Abstract
Spleen tyrosine kinase (SYK) plays a major role in inflammation and in adaptive immune responses and could therefore contribute to the neuroinflammation observed in various neurodegenerative diseases. Indeed, previously we have reported that SYK also regulates β-amyloid (Aβ) production and hyperphosphorylation of Tau protein involved in these diseases. Moreover, SYK hyperactivation occurs in a subset of activated microglia, in dystrophic neurites surrounding Aβ deposits, and in neurons affected by Tau pathology both in individuals with Alzheimer's disease (AD) and in AD mouse models. SYK activation increases Tau phosphorylation and accumulation, suggesting that SYK could be an attractive target for treating AD. However, the mechanism by which SYK affects Tau pathology is not clear. In this study, using cell biology and biochemical approaches, along with immunoprecipitation and immunoblotting, quantitative RT-PCR, and ELISAs, we found that SYK inhibition increases autophagic Tau degradation without impacting Tau production. Using neuron-like SH-SY5Y cells, we demonstrate that SYK acts upstream of the mammalian target of rapamycin (mTOR) pathway and that pharmacological inhibition or knockdown of SYK decreases mTOR pathway activation and increases autophagic Tau degradation. Interestingly, chronic SYK inhibition in a tauopathy mouse model profoundly reduced Tau accumulation, neuroinflammation, neuronal and synaptic loss, and also reversed defective autophagy. Our results further suggest that the SYK up-regulation observed in the brains of individuals with AD contributes to defective autophagic clearance leading to the accumulation of pathogenic Tau species. These findings further highlight SYK as a therapeutic target for the treatment of tauopathies and other neurodegenerative proteinopathies associated with defective autophagic clearance.
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Affiliation(s)
- Jonas Elias Schweig
- Roskamp Institute, Sarasota, Florida 34243; The Open University, Milton Keynes MK7 6AA, United Kingdom; James A. Haley Veterans Hospital, Tampa, Florida 33612.
| | - Hailan Yao
- Roskamp Institute, Sarasota, Florida 34243; James A. Haley Veterans Hospital, Tampa, Florida 33612
| | - Kyle Coppola
- Roskamp Institute, Sarasota, Florida 34243; James A. Haley Veterans Hospital, Tampa, Florida 33612
| | - Chao Jin
- Roskamp Institute, Sarasota, Florida 34243
| | - Fiona Crawford
- Roskamp Institute, Sarasota, Florida 34243; The Open University, Milton Keynes MK7 6AA, United Kingdom; James A. Haley Veterans Hospital, Tampa, Florida 33612
| | - Michael Mullan
- Roskamp Institute, Sarasota, Florida 34243; The Open University, Milton Keynes MK7 6AA, United Kingdom
| | - Daniel Paris
- Roskamp Institute, Sarasota, Florida 34243; The Open University, Milton Keynes MK7 6AA, United Kingdom; James A. Haley Veterans Hospital, Tampa, Florida 33612
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59
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Wehnekamp F, Plucińska G, Thong R, Misgeld T, Lamb DC. Nanoresolution real-time 3D orbital tracking for studying mitochondrial trafficking in vertebrate axons in vivo. eLife 2019; 8:46059. [PMID: 31180320 PMCID: PMC6579510 DOI: 10.7554/elife.46059] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 06/05/2019] [Indexed: 12/14/2022] Open
Abstract
We present the development and in vivo application of a feedback-based tracking microscope to follow individual mitochondria in sensory neurons of zebrafish larvae with nanometer precision and millisecond temporal resolution. By combining various technical improvements, we tracked individual mitochondria with unprecedented spatiotemporal resolution over distances of >100 µm. Using these nanoscopic trajectory data, we discriminated five motional states: a fast and a slow directional motion state in both the anterograde and retrograde directions and a stationary state. The transition pattern revealed that, after a pause, mitochondria predominantly persist in the original direction of travel, while transient changes of direction often exhibited longer pauses. Moreover, mitochondria in the vicinity of a second, stationary mitochondria displayed an increased probability to pause. The capability of following and optically manipulating a single organelle with high spatiotemporal resolution in a living organism offers a new approach to elucidating their function in its complete physiological context.
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Affiliation(s)
- Fabian Wehnekamp
- Department of Chemistry, Center for Nano Science (CENS), Center for Integrated Protein Science (CIPSM) and Nanosystems Initiative München (NIM), Ludwig Maximilians-Universität München, Munich, Germany
| | - Gabriela Plucińska
- Munich Cluster for Systems Neurology (SNergy), Center for Integrated Protein Science (CIPSM), German Center for Neurodegenerative Diseases (DZNE), Institute of Neuronal Cell Biology, Technische Universität München, Munich, Germany
| | - Rachel Thong
- Munich Cluster for Systems Neurology (SNergy), Center for Integrated Protein Science (CIPSM), German Center for Neurodegenerative Diseases (DZNE), Institute of Neuronal Cell Biology, Technische Universität München, Munich, Germany
| | - Thomas Misgeld
- Munich Cluster for Systems Neurology (SNergy), Center for Integrated Protein Science (CIPSM), German Center for Neurodegenerative Diseases (DZNE), Institute of Neuronal Cell Biology, Technische Universität München, Munich, Germany
| | - Don C Lamb
- Department of Chemistry, Center for Nano Science (CENS), Center for Integrated Protein Science (CIPSM) and Nanosystems Initiative München (NIM), Ludwig Maximilians-Universität München, Munich, Germany
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60
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Kuramochi M, Takanashi C, Yamauchi A, Doi M, Mio K, Tsuda S, Sasaki YC. Expression of Ice-Binding Proteins in Caenorhabditis elegans Improves the Survival Rate upon Cold Shock and during Freezing. Sci Rep 2019; 9:6246. [PMID: 31092839 PMCID: PMC6520345 DOI: 10.1038/s41598-019-42650-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 04/04/2019] [Indexed: 01/01/2023] Open
Abstract
Ice-binding proteins (IBPs) are capable of binding ice crystals and inhibiting their growth at freezing temperatures. IBPs are also thought to stabilize the cell membrane at non-freezing temperatures near 0 °C. These two effects have been assumed to reduce cold- and freezing-induced damage to cells and tissues. However, knowledge regarding the effects of IBP on the living animals is limited. Here, we characterized the relationship between the IBP effects and the physiological role by using the nematode Caenorhabditis elegans. The expression of fish (NfeIBPs)- and fungus-derived IBPs (AnpIBPs and TisIBP8) in C. elegans improved its survival rate during exposure to 0 and −2 °C (cold shock) and −5 °C (freezing). The observed cold tolerance of C. elegans after cold shock is attributable to the stabilization of cell-membrane lipids with IBPs, and the freezing tolerance at −5 °C can be attributed to the inhibition of ice-crystal growth by the IBPs. Significantly, the survival rate of C. elegans at −5 °C was improved by expression of wild-type AnpIBP and maximized by that of TisIBP8, whereas it was lowered when a defective AnpIBP mutant was expressed. These results suggest that the ice-binding ability of IBP has a good correlation with the survival rate of C. elegans during freezing.
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Affiliation(s)
- Masahiro Kuramochi
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8561, Japan. .,AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Kashiwa, 277-8565, Japan. .,Molecular Neurobiology Research Group and DAI-LAB, Biomedical Research Institute, National Institute of Advance Industrial Science and Technology (AIST), Tsukuba, 305-8566, Japan.
| | - Chiaki Takanashi
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8561, Japan.,AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Kashiwa, 277-8565, Japan
| | - Akari Yamauchi
- Graduate School of Life Science, Hokkaido University, Sapporo, 060-0810, Japan.,Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Sapporo, 062-8517, Japan
| | - Motomichi Doi
- Molecular Neurobiology Research Group and DAI-LAB, Biomedical Research Institute, National Institute of Advance Industrial Science and Technology (AIST), Tsukuba, 305-8566, Japan
| | - Kazuhiro Mio
- AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Kashiwa, 277-8565, Japan
| | - Sakae Tsuda
- AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Kashiwa, 277-8565, Japan. .,Graduate School of Life Science, Hokkaido University, Sapporo, 060-0810, Japan. .,Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Sapporo, 062-8517, Japan.
| | - Yuji C Sasaki
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8561, Japan. .,AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Kashiwa, 277-8565, Japan.
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61
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Screening of a neuronal cell model of tau pathology for therapeutic compounds. Neurobiol Aging 2019; 76:24-34. [DOI: 10.1016/j.neurobiolaging.2018.11.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/23/2018] [Accepted: 11/30/2018] [Indexed: 11/20/2022]
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62
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Mitophagy inhibits amyloid-β and tau pathology and reverses cognitive deficits in models of Alzheimer's disease. Nat Neurosci 2019; 22:401-412. [PMID: 30742114 DOI: 10.1038/s41593-018-0332-9] [Citation(s) in RCA: 940] [Impact Index Per Article: 188.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 12/17/2018] [Indexed: 01/21/2023]
Abstract
Accumulation of damaged mitochondria is a hallmark of aging and age-related neurodegeneration, including Alzheimer's disease (AD). The molecular mechanisms of impaired mitochondrial homeostasis in AD are being investigated. Here we provide evidence that mitophagy is impaired in the hippocampus of AD patients, in induced pluripotent stem cell-derived human AD neurons, and in animal AD models. In both amyloid-β (Aβ) and tau Caenorhabditis elegans models of AD, mitophagy stimulation (through NAD+ supplementation, urolithin A, and actinonin) reverses memory impairment through PINK-1 (PTEN-induced kinase-1)-, PDR-1 (Parkinson's disease-related-1; parkin)-, or DCT-1 (DAF-16/FOXO-controlled germline-tumor affecting-1)-dependent pathways. Mitophagy diminishes insoluble Aβ1-42 and Aβ1-40 and prevents cognitive impairment in an APP/PS1 mouse model through microglial phagocytosis of extracellular Aβ plaques and suppression of neuroinflammation. Mitophagy enhancement abolishes AD-related tau hyperphosphorylation in human neuronal cells and reverses memory impairment in transgenic tau nematodes and mice. Our findings suggest that impaired removal of defective mitochondria is a pivotal event in AD pathogenesis and that mitophagy represents a potential therapeutic intervention.
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63
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Tan CC, Zhang XY, Tan L, Yu JT. Tauopathies: Mechanisms and Therapeutic Strategies. J Alzheimers Dis 2019; 61:487-508. [PMID: 29278892 DOI: 10.3233/jad-170187] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Tauopathies are morphologically, biochemically, and clinically heterogeneous neurodegenerative diseases defined by the accumulation of abnormal tau proteins in the brain. There is no effective method to prevent and reverse the tauopathies, but this gloomy picture has been changed by recent research advances. Evidences from genetic studies, experimental animal models, and molecular and cell biology have shed light on the main mechanisms of the diseases. The development of radiology and biochemistry, especially the development of PET imaging, will provide important biomarkers for the clinical diagnosis and treatment. Given the central role of tau in tauopathies, many treatments have constantly emerged, including targeting phosphorylation, targeting aggregation, increasing microtubule stabilization, tau immunization, clearance of tau, anti-inflammatory treatment, and other therapeutics. There is still a long way to go before we obtain drug therapy targeted at multifactor mechanisms.
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Affiliation(s)
- Chen-Chen Tan
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, Shandong, China
| | - Xiao-Yan Zhang
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, Shandong, China
| | - Lan Tan
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, Shandong, China
| | - Jin-Tai Yu
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, Shandong, China
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Zhou L, Wang L, Zhang J, Li J, Bai S, Ma J, Fu X. Didymin improves UV irradiation resistance in C. elegans. PeerJ 2019; 6:e6218. [PMID: 30643686 PMCID: PMC6330030 DOI: 10.7717/peerj.6218] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 12/05/2018] [Indexed: 12/11/2022] Open
Abstract
Didymin, a type of flavono-o-glycoside compound naturally present in citrus fruits, has been reported to be an effective anticancer agent. However, its effects on stress resistance are unclear. In this study, we treated Caenorhabditis elegans with didymin at several concentrations. We found that didymin reduced the effects of UV stressor on nematodes by decreasing reactive oxygen species levels and increasing superoxide dismutase (SOD) activity. Furthermore, we found that specific didymin-treated mutant nematodes daf-16(mu86) & daf-2(e1370), daf-16(mu86), akt-1(ok525), akt-2(ok393), and age-1(hx546) were susceptible to UV irradiation, whereas daf-2(e1371) was resistant to UV irradiation. In addition, we found that didymin not only promoted DAF-16 to transfer from cytoplasm to nucleus, but also increased both protein and mRNA expression levels of SOD-3 and HSP-16.2 after UV irradiation. Our results show that didymin affects UV irradiation resistance and it may act on daf-2 to regulate downstream genes through the insulin/IGF-1-like signaling pathway.
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Affiliation(s)
- Lin Zhou
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin Province, China
| | - Lu Wang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin Province, China
| | - Jialing Zhang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin Province, China
| | - Jiahe Li
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin Province, China
| | - Shuju Bai
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin Province, China
| | - Junfeng Ma
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin Province, China
| | - Xueqi Fu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin Province, China
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65
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van Weering JRT, Scheper W. Endolysosome and Autolysosome Dysfunction in Alzheimer's Disease: Where Intracellular and Extracellular Meet. CNS Drugs 2019; 33:639-648. [PMID: 31165364 PMCID: PMC6647502 DOI: 10.1007/s40263-019-00643-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Disturbed proteostasis as reflected by a massive accumulation of misfolded protein aggregates is a central feature in Alzheimer's disease. Proteostatic disturbances may be caused by a shift in protein production and clearance. Whereas rare genetic causes of the disease affect the production side, sporadic cases appear to be directed by dysfunction in protein clearance. This review focusses on the involvement of lysosome-mediated clearance. Autophagy is a degradational system where intracellular components are degraded by lysosomal organelles. In addition, "outside-to-inside" trafficking through the endosomes converges with the autolysosomal pathway, thereby bringing together intracellular and extracellular components. Recent findings demonstrate that disturbance in the endo- and autolysosomal pathway induces "inside-to-outside" communication via induction of unconventional secretion, which may bear relevance to the spreading of disease pathology through the brain. The involvement of these pathways in the pathogenesis of the disease is discussed with an outlook to the opportunities it provides for diagnostics as well as therapeutic interventions.
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Affiliation(s)
- Jan R. T. van Weering
- 0000 0004 1754 9227grid.12380.38Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU Faculty of Science, Vrije Universiteit (VU), De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands ,0000000084992262grid.7177.6Department of Clinical Genetics, Amsterdam University Medical Centers Location VUmc, Amsterdam, Netherlands
| | - Wiep Scheper
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU Faculty of Science, Vrije Universiteit (VU), De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands. .,Department of Clinical Genetics, Amsterdam University Medical Centers Location VUmc, Amsterdam, Netherlands. .,Alzheimer Center, Amsterdam University Medical Centers Location VUmc, Amsterdam, Netherlands.
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Pir GJ, Choudhary B, Kaniyappan S, Chandupatla RR, Mandelkow E, Mandelkow EM, Wang Y. Suppressing Tau Aggregation and Toxicity by an Anti-Aggregant Tau Fragment. Mol Neurobiol 2018; 56:3751-3767. [PMID: 30196394 PMCID: PMC6476873 DOI: 10.1007/s12035-018-1326-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 08/20/2018] [Indexed: 11/24/2022]
Abstract
Tau aggregation is a hallmark of a group of neurodegenerative diseases termed Tauopathies. Reduction of aggregation-prone Tau has emerged as a promising therapeutic approach. Here, we show that an anti-aggregant Tau fragment (F3ΔKPP, residues 258–360) harboring the ΔK280 mutation and two proline substitutions (I277P & I308P) in the repeat domain can inhibit aggregation of Tau constructs in vitro, in cultured cells and in vivo in a Caenorhabditis elegans model of Tau aggregation. The Tau fragment reduced Tau-dependent cytotoxicity in a N2a cell model, suppressed the Tau-mediated neuronal dysfunction and ameliorated the defective locomotion in C. elegans. In vitro the fragment competes with full-length Tau for polyanionic aggregation inducers and thus inhibits Tau aggregation. Our combined in vitro and in vivo results suggest that the anti-aggregant Tau fragment may potentially be used to address the consequences of Tau aggregation in Tauopathies.
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Affiliation(s)
- Ghulam Jeelani Pir
- German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127, Bonn, Germany. .,Max-Planck-Institute for Metabolism Research, Hamburg Outstation, c/o DESY, Notkestrasse 85, 22607, Hamburg, Germany.
| | - Bikash Choudhary
- German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127, Bonn, Germany.,Max-Planck-Institute for Metabolism Research, Hamburg Outstation, c/o DESY, Notkestrasse 85, 22607, Hamburg, Germany
| | - Senthilvelrajan Kaniyappan
- German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127, Bonn, Germany.,Max-Planck-Institute for Metabolism Research, Hamburg Outstation, c/o DESY, Notkestrasse 85, 22607, Hamburg, Germany
| | - Ram Reddy Chandupatla
- German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127, Bonn, Germany.,Max-Planck-Institute for Metabolism Research, Hamburg Outstation, c/o DESY, Notkestrasse 85, 22607, Hamburg, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127, Bonn, Germany.,Max-Planck-Institute for Metabolism Research, Hamburg Outstation, c/o DESY, Notkestrasse 85, 22607, Hamburg, Germany.,CAESAR Research Center, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
| | - Eva-Maria Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127, Bonn, Germany. .,Max-Planck-Institute for Metabolism Research, Hamburg Outstation, c/o DESY, Notkestrasse 85, 22607, Hamburg, Germany. .,CAESAR Research Center, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.
| | - Yipeng Wang
- German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127, Bonn, Germany. .,Max-Planck-Institute for Metabolism Research, Hamburg Outstation, c/o DESY, Notkestrasse 85, 22607, Hamburg, Germany.
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67
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Savelieff MG, Nam G, Kang J, Lee HJ, Lee M, Lim MH. Development of Multifunctional Molecules as Potential Therapeutic Candidates for Alzheimer’s Disease, Parkinson’s Disease, and Amyotrophic Lateral Sclerosis in the Last Decade. Chem Rev 2018; 119:1221-1322. [DOI: 10.1021/acs.chemrev.8b00138] [Citation(s) in RCA: 270] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Masha G. Savelieff
- SciGency Science Communications, Ann Arbor, Michigan 48104, United States
| | - Geewoo Nam
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Juhye Kang
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Hyuck Jin Lee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Misun Lee
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Mi Hee Lim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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68
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Ahmad W. Dihydrolipoamide dehydrogenase suppression induces human tau phosphorylation by increasing whole body glucose levels in a C. elegans model of Alzheimer's Disease. Exp Brain Res 2018; 236:2857-2866. [PMID: 30056470 DOI: 10.1007/s00221-018-5341-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 07/21/2018] [Indexed: 12/01/2022]
Abstract
The microtubule associated tau protein becomes hyperphosphorylated in Alzheimer's disease (AD). While hyperphosphorylation promotes neurodegeneration, the cause and consequences of this abnormal modification are poorly understood. As impaired energy metabolism is an important hallmark of AD progression, we tested whether it could trigger phosphorylation of human tau protein in a transgenic Caenorhabditis elegans model of AD. We found that inhibition of a mitochondrial enzyme of energy metabolism, dihydrolipoamide dehydrogenase (DLD) results in elevated whole-body glucose levels as well as increased phosphorylation of tau. Hyperglycemia and tau phosphorylation were induced by either RNAi suppression of the dld-1 gene or by inhibition of the DLD enzyme by the inhibitor, 2-methoxyindole-2-carboxylic acid (MICA). Although the calcium ionophore A23187 could reduce tau phosphorylation induced by either chemical or genetic suppression of DLD, it was unable to reduce tau phosphorylation induced by hyperglycemia. While inhibition of the dld-1 gene or treatment with MICA partially reversed the inhibition of acetylcholine neurotransmission by tau, neither treatment affected tau inhibited mobility. Conclusively, any abnormalities in energy metabolism were found to significantly affect the AD disease pathology.
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Affiliation(s)
- Waqar Ahmad
- School of Biological Sciences, The University of Queensland, Brisbane, 4072, Australia.
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69
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Sarasija S, Laboy JT, Ashkavand Z, Bonner J, Tang Y, Norman KR. Presenilin mutations deregulate mitochondrial Ca 2+ homeostasis and metabolic activity causing neurodegeneration in Caenorhabditis elegans. eLife 2018; 7:33052. [PMID: 29989545 PMCID: PMC6075864 DOI: 10.7554/elife.33052] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 07/09/2018] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial dysfunction and subsequent metabolic deregulation is observed in neurodegenerative diseases and aging. Mutations in the presenilin (PSEN) encoding genes (PSEN1 and PSEN2) cause most cases of familial Alzheimer’s disease (AD); however, the underlying mechanism of pathogenesis remains unclear. Here, we show that mutations in the C. elegans gene encoding a PSEN homolog, sel-12 result in mitochondrial metabolic defects that promote neurodegeneration as a result of oxidative stress. In sel-12 mutants, elevated endoplasmic reticulum (ER)-mitochondrial Ca2+ signaling leads to an increase in mitochondrial Ca2+ content which stimulates mitochondrial respiration resulting in an increase in mitochondrial superoxide production. By reducing ER Ca2+ release, mitochondrial Ca2+ uptake or mitochondrial superoxides in sel-12 mutants, we demonstrate rescue of the mitochondrial metabolic defects and prevent neurodegeneration. These data suggest that mutations in PSEN alter mitochondrial metabolic function via ER to mitochondrial Ca2+ signaling and provide insight for alternative targets for treating neurodegenerative diseases. Alzheimer's disease is the most common type of dementia. A hallmark of this condition is progressive loss of memory, accompanied by a buildup of hard clumps of protein between the brain cells. These protein clumps, known as amyloid plaques, are a key focus of research into Alzheimer's disease. They are likely to be toxic to brain cells, but their role in the development and progression of the disease is not yet known. Though the cause of Alzheimer's disease remains unclear, an inherited form of the disease may hold some clues. Mutations in genes for proteins called presenilins cause an earlier onset form of Alzheimer's disease, in which symptoms can develop in people who are in their 40s or 50s. The presenilin proteins appear in a cell structure called the endoplasmic reticulum, which plays many roles in the normal activities of a cell. Among other things, this structure stores and releases calcium ions, and cells use these ions to send and process many signals. The cell's energy-producing powerhouses, the mitochondria, use calcium to boost their metabolic activity. This allows them to make more energy for the cell, but in the process they also make damaging byproducts. These byproducts include oxygen-containing chemicals, known as reactive oxygen species (ROS), which react strongly with other molecules. While low levels of ROS are a normal part of cell activity, if the levels get too high, these chemicals can attack and damage structures within the cell. Untangling the effects of amyloid plaques and presenilins on brain cells in humans is challenging. But, a nematode worm called Caenorhabditis elegans does not form plaques, making it possible to look at presenilins on their own. Previous work in these worms has shown that presenilin mutations affect the endoplasmic reticulum and change the appearance of mitochondria. Here, Sarasija et al. extend this work to find out more about the effects presenilin mutations have on living cells. Presenilin mutations in young adult worms increased the amount of calcium released by the endoplasmic reticulum. This increased the activity of the mitochondria and caused ROS levels to rise to damaging levels. This caused stress inside the cells, and the worms started to show early signs damage to their nervous systems. Mutations that decreased the movement of calcium from the endoplasmic reticulum to the mitochondria helped to prevent the damage. Treating the mitochondria with antioxidants to mop up the extra ROS also protected the cells. This kind of damage to brain cells did not depend on amyloid plaques. Whilst the plaques are likely to be toxic, these new findings highlights the role that other chemical and biological processes might play in Alzheimer's disease. Further work to reveal the underlying cause of Alzheimer's disease may lead to new therapies to treat this condition in the future.
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Affiliation(s)
- Shaarika Sarasija
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, United States
| | - Jocelyn T Laboy
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, United States
| | - Zahra Ashkavand
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, United States
| | - Jennifer Bonner
- Department of Biology, Skidmore College, Saratoga Springs, United States
| | - Yi Tang
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, United States
| | - Kenneth R Norman
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, United States
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V363I and V363A mutated tau affect aggregation and neuronal dysfunction differently in C. elegans. Neurobiol Dis 2018; 117:226-234. [PMID: 29936232 DOI: 10.1016/j.nbd.2018.06.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 06/18/2018] [Accepted: 06/20/2018] [Indexed: 11/24/2022] Open
Abstract
Mutations in the microtubule-associated protein tau (MAPT) gene have been linked to a heterogeneous group of progressive neurodegenerative disorders commonly called tauopathies. From patients with frontotemporal lobar degeneration with distinct atypical clinical phenotypes, we recently identified two new mutations on the same codon, in position 363 of the MAPT gene, which resulted in the production of Val-to-Ala (tauV363A) or Val-to-Ile (tauV363I) mutated tau. These substitutions specifically affected microtubule polymerization and propensity of tau to aggregate in vitro suggesting that single amino acid modification may dictate the fate of the neuropathology. To clarify whether tauV363A and tauV363I affect protein misfolding differently in vivo driving certain phenotypes, we generated new transgenic C. elegans strains. Human 2N4R tau carrying the mutation was expressed in all the neurons of worms. The behavioral defects, misfolding and proteotoxicity caused by the tauV363A and tauV363I mutated proteins were compared to that induced by the expression of wild-type tau (tauwt). Pan-neuronal expression of human 2N4R tauWT in worms resulted in a neuromuscular defect with characteristics of a neurodegenerative phenotype. This defect was worsened by the expression of mutated proteins which drive distinct neuronal dysfunctions and synaptic impairments involving, in transgenic worms expressing tauV363A (V363A) also a pharyngeal defect never linked before to other mutations. The two mutations differently affected the tau phosphorylation and misfolding propensities: tauV363I was highly phosphorylated on epitopes corresponding to Thr231 and Ser202/Thr205, and accumulated as insoluble tau assemblies whereas tauV363A showed a greater propensity to form soluble oligomeric assemblies. These findings uphold the role of a single amino acid substitution in specifically affecting the ability of tau to form soluble and insoluble assemblies, opening up new perspectives in the pathogenic mechanism underlying tauopathies.
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Abstract
Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder affecting millions of people worldwide. Therefore, finding effective interventions and therapies is extremely important. AD is one of over 20 different disorders known as tauopathies, characterized by the pathological aggregation and accumulation of tau, a microtubule-associated protein. Tau aggregates are heterogeneous and can be divided into two major groups: large metastable fibrils, including neurofibrillary tangles, and oligomers. The smaller, soluble and dynamic tau oligomers have been shown to be more toxic with more proficient seeding properties for the propagation of tau pathology as compared to the fibrillar Paired Helical Filaments (PHFs). Therefore, developing small molecules that target and interact with toxic tau oligomers can be beneficial to modulate their aggregation pathways and toxicity, preventing progression of the pathology. In this study, we show that Azure C (AC) is capable of modulating tau oligomer aggregation pathways at micromolar concentrations and rescues tau oligomers-induced toxicity in cell culture. We used both biochemical and biophysical in vitro techniques to characterize preformed tau oligomers in the presence and absence of AC. Interestingly, AC prevents toxicity not by disassembling the oligomers but rather by converting them into clusters of aggregates with nontoxic conformation.
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Affiliation(s)
- Filippa Lo Cascio
- Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, Texas 77555, United States
- Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555, United States
- Department of Experimental Biomedicine and Clinical Neuroscience, University of Palermo, 90127 Palermo, Italy
| | - Rakez Kayed
- Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, Texas 77555, United States
- Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555, United States
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72
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UNC-16/JIP3 and UNC-76/FEZ1 limit the density of mitochondria in C. elegans neurons by maintaining the balance of anterograde and retrograde mitochondrial transport. Sci Rep 2018; 8:8938. [PMID: 29895958 PMCID: PMC5997755 DOI: 10.1038/s41598-018-27211-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 05/25/2018] [Indexed: 12/23/2022] Open
Abstract
We investigate the role of axonal transport in regulating neuronal mitochondrial density. We show that the density of mitochondria in the touch receptor neuron (TRN) of adult Caenorhabditis elegans is constant. Mitochondrial density and transport are controlled both by the Kinesin heavy chain and the Dynein-Dynactin complex. However, unlike in other models, the presence of mitochondria in C. elegans TRNs depends on a Kinesin light chain as well. Mutants in the three C. elegans miro genes do not alter mitochondrial density in the TRNs. Mutants in the Kinesin-1 associated proteins, UNC-16/JIP3 and UNC-76/FEZ1, show increased mitochondrial density and also have elevated levels of both the Kinesin Heavy and Light Chains in neurons. Genetic analyses suggest that, the increased mitochondrial density at the distal end of the neuronal process in unc-16 and unc-76 depends partly on Dynein. We observe a net anterograde bias in the ratio of anterograde to retrograde mitochondrial flux in the neuronal processes of unc-16 and unc-76, likely due to both increased Kinesin-1 and decreased Dynein in the neuronal processes. Our study shows that UNC-16 and UNC-76 indirectly limit mitochondrial density in the neuronal process by maintaining a balance in anterograde and retrograde mitochondrial axonal transport.
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73
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Choudhary B, Mandelkow E, Mandelkow EM, Pir GJ. Glutamatergic nervous system degeneration in a C. elegans Tau A152T tauopathy model involves pathways of excitotoxicity and Ca 2+ dysregulation. Neurobiol Dis 2018; 117:189-202. [PMID: 29894752 DOI: 10.1016/j.nbd.2018.06.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 05/28/2018] [Accepted: 06/07/2018] [Indexed: 10/14/2022] Open
Abstract
Mutations in the gene encoding Tau (MAPT-microtubule-associated protein tau) cause a group of neurodegenerative diseases called tauopathies. A recently identified Tau variant, p.A152T, has been reported as a risk factor for frontotemporal dementia-related disorders and Alzheimer disease. However, the mechanism for the pathologies still remain poorly understood. Transgenic Caenorhabditis elegans expressing mutant 2N4R-TauA152T (TauAT) panneuronally show locomotor defects, neurodegeneration and accelerated aging. Here we report that, in TauAT animals, the glutamatergic nervous system is at a high risk of progressive neuronal loss. We present genetic data that this loss occurs predominantly through necrosis. The neuronal loss is caused by several determinants, such as altered adenylyl cyclase (type AC9) pathway, prevalence of excitotoxicity-like conditions, aging-related factors and finally dyshomeostasis of intracellular calcium (Ca2+). The study provides novel insights into the mechanisms involved in selective loss of glutamatergic neurons in a TauAT tauopathy model which could point to new therapeutic targets.
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Affiliation(s)
- Bikash Choudhary
- German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud St. 27, 53127 Bonn, Germany; Max-Planck-Institute for Metabolism Research, Hamburg Outstation, c/o DESY, Notkestrsse 85, 22607 Hamburg, Germany.
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud St. 27, 53127 Bonn, Germany; Caesar Research Center, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany; Max-Planck-Institute for Metabolism Research, Hamburg Outstation, c/o DESY, Notkestrsse 85, 22607 Hamburg, Germany.
| | - Eva-Maria Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud St. 27, 53127 Bonn, Germany; Caesar Research Center, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany; Max-Planck-Institute for Metabolism Research, Hamburg Outstation, c/o DESY, Notkestrsse 85, 22607 Hamburg, Germany.
| | - Ghulam Jeelani Pir
- German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud St. 27, 53127 Bonn, Germany; Max-Planck-Institute for Metabolism Research, Hamburg Outstation, c/o DESY, Notkestrsse 85, 22607 Hamburg, Germany.
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74
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Tucker D, Lu Y, Zhang Q. From Mitochondrial Function to Neuroprotection-an Emerging Role for Methylene Blue. Mol Neurobiol 2018; 55:5137-5153. [PMID: 28840449 PMCID: PMC5826781 DOI: 10.1007/s12035-017-0712-2] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 08/07/2017] [Indexed: 12/23/2022]
Abstract
Methylene blue (MB) is a well-established drug with a long history of use, owing to its diverse range of use and its minimal side effect profile. MB has been used classically for the treatment of malaria, methemoglobinemia, and carbon monoxide poisoning, as well as a histological dye. Its role in the mitochondria, however, has elicited much of its renewed interest in recent years. MB can reroute electrons in the mitochondrial electron transfer chain directly from NADH to cytochrome c, increasing the activity of complex IV and effectively promoting mitochondrial activity while mitigating oxidative stress. In addition to its beneficial effect on mitochondrial protection, MB is also known to have robust effects in mitigating neuroinflammation. Mitochondrial dysfunction has been identified as a seemingly unifying pathological phenomenon across a wide range of neurodegenerative disorders, which thus positions methylene blue as a promising therapeutic. In both in vitro and in vivo studies, MB has shown impressive efficacy in mitigating neurodegeneration and the accompanying behavioral phenotypes in animal models for such conditions as stroke, global cerebral ischemia, Alzheimer's disease, Parkinson's disease, and traumatic brain injury. This review summarizes recent work establishing MB as a promising candidate for neuroprotection, with particular emphasis on the contribution of mitochondrial function to neural health. Furthermore, this review will briefly examine the link between MB, neurogenesis, and improved cognition in respect to age-related cognitive decline.
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Affiliation(s)
- Donovan Tucker
- Department of Neuroscience and Regenerative Medicine, Augusta University, 1120 15th Street, Augusta, GA, 30912, USA
| | - Yujiao Lu
- Department of Neuroscience and Regenerative Medicine, Augusta University, 1120 15th Street, Augusta, GA, 30912, USA
| | - Quanguang Zhang
- Department of Neuroscience and Regenerative Medicine, Augusta University, 1120 15th Street, Augusta, GA, 30912, USA.
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75
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Shen P, Yue Y, Zheng J, Park Y. Caenorhabditis elegans: A Convenient In Vivo Model for Assessing the Impact of Food Bioactive Compounds on Obesity, Aging, and Alzheimer's Disease. Annu Rev Food Sci Technol 2018; 9:1-22. [DOI: 10.1146/annurev-food-030117-012709] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Peiyi Shen
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - Yiren Yue
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts 01003, USA
| | | | - Yeonhwa Park
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts 01003, USA
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76
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Manalo RVM, Medina PMB. Caffeine Protects Dopaminergic Neurons From Dopamine-Induced Neurodegeneration via Synergistic Adenosine-Dopamine D2-Like Receptor Interactions in Transgenic Caenorhabditis elegans. Front Neurosci 2018; 12:137. [PMID: 29563862 PMCID: PMC5845907 DOI: 10.3389/fnins.2018.00137] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 02/20/2018] [Indexed: 12/15/2022] Open
Abstract
Previous studies have suggested that caffeine reduces the risk of L-DOPA-induced dyskinesia. However, caffeine is also known to promote dopamine signaling, which seemingly contradicts this observed effect. To this end, the study aimed to clarify the mechanism of caffeine neuroprotection in vivo when excess dopamine is present. Transgenic Caenorhabditis elegans (UA57) overproducing dopamine was exposed to caffeine for 7 days and monitored by observing GFP-tagged dopaminergic (DA) neurons via fluorescence microscopy. Caffeine (10 mM) prevented neuronal cell loss in 96% of DA neurons, with a mean GFP intensity that is 40% higher than control (0.1% DMSO). To confirm if cAMP plays a role in the observed neuroprotection by caffeine, cAMP levels were elevated via forskolin (10 μM), an adenylyl cyclase activator. Forskolin (10 μM) exposure did not confer neuroprotection and was similar to control (0.1% DMSO) at the 7th day, suggesting that cAMP is not the sole secondary messenger utilized. Rotigotine (160 μM), a dopamine D2-like receptor (DOP2R) agonist, was not able to confer significant neuroprotection to the nematodes. This suggests that DOP2R activation is necessary but insufficient to mimic neuroprotection by caffeine. Lastly, co-administration of caffeine (10 mM) with olanzapine (160 μM), a DOP2R antagonist, eliminated neuroprotection. This suggests that the protective effect must involve both adenosine receptor antagonism and activation of DOP2Rs. Taken together, we show that caffeine protects DA neurons from dopamine-induced neurodegeneration and acts by modulating adenosine receptor-DOP2R interactions in C. elegans.
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Affiliation(s)
- Rafael V M Manalo
- Biological Models Laboratory, Department of Biochemistry and Molecular Biology, College of Medicine, University of the Philippines Manila, Manila, Philippines
| | - Paul M B Medina
- Biological Models Laboratory, Department of Biochemistry and Molecular Biology, College of Medicine, University of the Philippines Manila, Manila, Philippines
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77
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Sarasija S, Norman KR. Analysis of Mitochondrial Structure in the Body Wall Muscle of Caenorhabditis elegans. Bio Protoc 2018; 8:e2801. [PMID: 29707607 DOI: 10.21769/bioprotoc.2801] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Mitochondrial function is altered in various pathologies, highlighting the crucial role mitochondria plays in maintaining cellular homeostasis. Mitochondrial structure undergoes constant fission and fusion in response to changing cellular environment. Due to this, analyzing mitochondrial structure could provide insight into the physiological state of the cell. In this protocol, we describe a method to analyze mitochondrial structure in body wall muscles in the nematode Caenorhabditis elegans, using both transgenic and dye-based approaches.
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Affiliation(s)
- Shaarika Sarasija
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, NY, USA
| | - Kenneth R Norman
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, NY, USA
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78
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Griffin EF, Caldwell KA, Caldwell GA. Genetic and Pharmacological Discovery for Alzheimer's Disease Using Caenorhabditis elegans. ACS Chem Neurosci 2017; 8:2596-2606. [PMID: 29022701 DOI: 10.1021/acschemneuro.7b00361] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The societal burden presented by Alzheimer's disease warrants both innovative and expedient means by which its underlying molecular causes can be both identified and mechanistically exploited to discern novel therapeutic targets and strategies. The conserved characteristics, defined neuroanatomy, and advanced technological application of Caenorhabditis elegans render this metazoan an unmatched tool for probing neurotoxic factors. In addition, its short lifespan and importance in the field of aging make it an ideal organism for modeling age-related neurodegenerative disease. As such, this nematode system has demonstrated its value in predicting functional modifiers of human neurodegenerative disorders. Here, we review how C. elegans has been utilized to model Alzheimer's disease. Specifically, we present how the causative neurotoxic peptides, amyloid-β and tau, contribute to disease-like neurodegeneration in C. elegans and how they translate to human disease. Furthermore, we describe how a variety of transgenic animal strains, each with distinct utility, have been used to identify both genetic and pharmacological modifiers of toxicity in C. elegans. As technological advances improve the prospects for intervention, the rapidity, unparalleled accuracy, and scale that C. elegans offers researchers for defining functional modifiers of neurodegeneration should speed the discovery of improved therapies for Alzheimer's disease.
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Affiliation(s)
- Edward F. Griffin
- Department
of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Kim A. Caldwell
- Department
of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Guy A. Caldwell
- Department
of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487, United States
- Departments
of Neurology and Neurobiology, Center for Neurodegeneration and Experimental
Therapeutics, The University of Alabama School of Medicine at Birmingham, Birmingham, Alabama 35294, United States
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79
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Dehghan E, Zhang Y, Saremi B, Yadavali S, Hakimi A, Dehghani M, Goodarzi M, Tu X, Robertson S, Lin R, Chudhuri A, Mirzaei H. Hydralazine induces stress resistance and extends C. elegans lifespan by activating the NRF2/SKN-1 signalling pathway. Nat Commun 2017; 8:2223. [PMID: 29263362 PMCID: PMC5738364 DOI: 10.1038/s41467-017-02394-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 11/24/2017] [Indexed: 12/13/2022] Open
Abstract
Nuclear factor (erythroid-derived 2)-like 2 and its Caenorhabditis elegans ortholog, SKN-1, are transcription factors that have a pivotal role in the oxidative stress response, cellular homeostasis, and organismal lifespan. Similar to other defense systems, the NRF2-mediated stress response is compromised in aging and neurodegenerative diseases. Here, we report that the FDA approved drug hydralazine is a bona fide activator of the NRF2/SKN-1 signaling pathway. We demonstrate that hydralazine extends healthy lifespan (~25%) in wild type and tauopathy model C. elegans at least as effectively as other anti-aging compounds, such as curcumin and metformin. We show that hydralazine-mediated lifespan extension is SKN-1 dependent, with a mechanism most likely mimicking calorie restriction. Using both in vitro and in vivo models, we go on to demonstrate that hydralazine has neuroprotective properties against endogenous and exogenous stressors. Our data suggest that hydralazine may be a viable candidate for the treatment of age-related disorders.
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Affiliation(s)
- Esmaeil Dehghan
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Yiqiang Zhang
- Greehey Children's Cancer Research Institute, UT Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Bahar Saremi
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | | | - Amirmansoor Hakimi
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Maryam Dehghani
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Mohammad Goodarzi
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Xiaoqin Tu
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Scott Robertson
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Rueyling Lin
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Asish Chudhuri
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Hamid Mirzaei
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX, 75390, USA.
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80
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Pir GJ, Choudhary B, Mandelkow E. Caenorhabditis elegans models of tauopathy. FASEB J 2017; 31:5137-5148. [PMID: 29191965 DOI: 10.1096/fj.201701007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 09/20/2017] [Indexed: 12/14/2022]
Abstract
One of the hallmarks of the tauopathies, which include the neurodegenerative disorders, such as Alzheimer disease (AD), corticobasal degeneration, frontotemporal dementia, and progressive supranuclear palsy (PSP), is the abnormal accumulation of post-translationally modified, insoluble tau. The result is a loss of neurons, decreased mental function, and complete dependence of patients on others. Aggregation of tau, which under physiologic conditions is a highly soluble protein, is thought to be central to the pathogenesis of these diseases. Indeed one of the strongest lines of evidence is the MAPT gene polymorphisms that lead to the familial forms of tauopathy. Extensive research in animal models over the years has contributed some of the most important findings regarding the pathogenesis of these diseases. Despite this, the precise molecular mechanisms that lead to abnormal tau folding, accumulation, and spreading remain unknown. Owing to the fact that most of the biochemical pathways are conserved, Caenorhabditis elegans provides an alternative approach to identify cellular mechanisms and druggable genes that operate in such disorders. Many human genes implicated in neurodegenerative diseases have counterparts in C. elegans, making it an excellent model in which to study their pathogenesis. In this article, we review some of the important findings gained from C. elegans tauopathy models.-Pir, G. J., Choudhary, B., Mandelkow, E. Caenorhabditiselegans models of tauopathy.
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Affiliation(s)
- Ghulam Jeelani Pir
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany; .,Max-Planck-Institute for Metabolism Research-Cologne, Hamburg, Germany
| | - Bikash Choudhary
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Max-Planck-Institute for Metabolism Research-Cologne, Hamburg, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Max-Planck-Institute for Metabolism Research-Cologne, Hamburg, Germany.,Caesar Research Center, Bonn, Germany
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81
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Ayyadevara S, Balasubramaniam M, Kakraba S, Alla R, Mehta JL, Shmookler Reis RJ. Aspirin-Mediated Acetylation Protects Against Multiple Neurodegenerative Pathologies by Impeding Protein Aggregation. Antioxid Redox Signal 2017; 27:1383-1396. [PMID: 28537433 PMCID: PMC5661865 DOI: 10.1089/ars.2016.6978] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
AIMS Many progressive neurological disorders, including Alzheimer's disease (AD), Huntington's disease, and Parkinson's disease (PD), are characterized by accumulation of insoluble protein aggregates. In prospective trials, the cyclooxygenase inhibitor aspirin (acetylsalicylic acid) reduced the risk of AD and PD, as well as cardiovascular events and many late-onset cancers. Considering the role played by protein hyperphosphorylation in aggregation and neurodegenerative diseases, and aspirin's known ability to donate acetyl groups, we asked whether aspirin might reduce both phosphorylation and aggregation by acetylating protein targets. RESULTS Aspirin was substantially more effective than salicylate in reducing or delaying aggregation in human neuroblastoma cells grown in vitro, and in Caenorhabditis elegans models of human neurodegenerative diseases in vivo. Aspirin acetylates many proteins, while reducing phosphorylation, suggesting that acetylation may oppose phosphorylation. Surprisingly, acetylated proteins were largely excluded from compact aggregates. Molecular-dynamic simulations indicate that acetylation of amyloid peptide energetically disfavors its association into dimers and octamers, and oligomers that do form are less compact and stable than those comprising unacetylated peptides. INNOVATION Hyperphosphorylation predisposes certain proteins to aggregate (e.g., tau, α-synuclein, and transactive response DNA-binding protein 43 [TDP-43]), and it is a critical pathogenic marker in both cardiovascular and neurodegenerative diseases. We present novel evidence that acetylated proteins are underrepresented in protein aggregates, and that aggregation varies inversely with acetylation propensity after diverse genetic and pharmacologic interventions. CONCLUSIONS These results are consistent with the hypothesis that aspirin inhibits protein aggregation and the ensuing toxicity of aggregates through its acetyl-donating activity. This mechanism may contribute to the neuro-protective, cardio-protective, and life-prolonging effects of aspirin. Antioxid. Redox Signal. 27, 1383-1396.
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Affiliation(s)
- Srinivas Ayyadevara
- 1 Central Arkansas Veterans Healthcare System, Research & Development Service , Little Rock, Arkansas.,2 Department of Geriatrics, Reynolds Institute on Aging, University of Arkansas for Medical Sciences , Little Rock, Arkansas
| | - Meenakshisundaram Balasubramaniam
- 1 Central Arkansas Veterans Healthcare System, Research & Development Service , Little Rock, Arkansas.,2 Department of Geriatrics, Reynolds Institute on Aging, University of Arkansas for Medical Sciences , Little Rock, Arkansas
| | - Samuel Kakraba
- 3 Bioinformatics Program, University of Arkansas for Medical Sciences, and University of Arkansas at Little Rock , Little Rock, Arkansas
| | - Ramani Alla
- 1 Central Arkansas Veterans Healthcare System, Research & Development Service , Little Rock, Arkansas.,2 Department of Geriatrics, Reynolds Institute on Aging, University of Arkansas for Medical Sciences , Little Rock, Arkansas
| | - Jawahar L Mehta
- 1 Central Arkansas Veterans Healthcare System, Research & Development Service , Little Rock, Arkansas.,4 Divison of Cardiology, Department of Medicine, University of Arkansas for Medical Sciences , Little Rock, Arkansas
| | - Robert J Shmookler Reis
- 1 Central Arkansas Veterans Healthcare System, Research & Development Service , Little Rock, Arkansas.,2 Department of Geriatrics, Reynolds Institute on Aging, University of Arkansas for Medical Sciences , Little Rock, Arkansas.,3 Bioinformatics Program, University of Arkansas for Medical Sciences, and University of Arkansas at Little Rock , Little Rock, Arkansas
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82
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Misgeld T, Schwarz TL. Mitostasis in Neurons: Maintaining Mitochondria in an Extended Cellular Architecture. Neuron 2017; 96:651-666. [PMID: 29096078 DOI: 10.1016/j.neuron.2017.09.055] [Citation(s) in RCA: 309] [Impact Index Per Article: 44.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Revised: 09/25/2017] [Accepted: 09/28/2017] [Indexed: 02/06/2023]
Abstract
Neurons have more extended and complex shapes than other cells and consequently face a greater challenge in distributing and maintaining mitochondria throughout their arbors. Neurons can last a lifetime, but proteins turn over rapidly. Mitochondria, therefore, need constant rejuvenation no matter how far they are from the soma. Axonal transport of mitochondria and mitochondrial fission and fusion contribute to this rejuvenation, but local protein synthesis is also likely. Maintenance of a healthy mitochondrial population also requires the clearance of damaged proteins and organelles. This involves degradation of individual proteins, sequestration in mitochondria-derived vesicles, organelle degradation by mitophagy and macroautophagy, and in some cases transfer to glial cells. Both long-range transport and local processing are thus at work in achieving neuronal mitostasis-the maintenance of an appropriately distributed pool of healthy mitochondria for the duration of a neuron's life. Accordingly, defects in the processes that support mitostasis are significant contributors to neurodegenerative disorders.
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Affiliation(s)
- Thomas Misgeld
- Technical University of Munich, Institute of Neuronal Cell Biology, Munich, Germany; German Center for Neurodegenerative Diseases, Munich, Germany; Munich Cluster for Systems Neurology, Munich, Germany; Center of Integrated Protein Science, Munich, Germany.
| | - Thomas L Schwarz
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA; F.M. Kirby Neurobiology Center, Children's Hospital, Boston, MA, USA.
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83
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Khosravi Z, Nasiri Khalili MA, Moradi S, Hassan Sajedi R, Zeinoddini M. The Molecular Chaperone Artemin Efficiently Blocks Fibrillization of TAU Protein In Vitro. CELL JOURNAL 2017; 19:569-577. [PMID: 29105391 PMCID: PMC5672095 DOI: 10.22074/cellj.2018.4510] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 11/03/2016] [Indexed: 11/17/2022]
Abstract
Objective Aggregation of the TAU proteins in the form of neurofibrillary tangles (NFTs) in the brain is a common risk
factor in tauopathies including Alzheimer’s disease (AD). Several strategies have been implemented to target NFTs,
among which chaperones, which facilitate the proper folding of proteins, appear to hold great promise in effectively
inhibiting TAU polymerization. The aim of this study was to analyze the impact of the chaperone Artemin on TAU
aggregation in vitro.
Materials and Methods In this experimental study, recombinant TAU- or Artemin proteins were expressed in E.coli
bacteria, and purified using ion-exchange and affinity chromatography. Sodium dodecyl sulfate-poly acrylamide gel
electrophoresis (SDS-PAGE) was used to run the extracted proteins and check their purity. Heparin was used as an
aggregation inducer. The interaction kinetics of TAU aggregation and disassembly was performed using thioflavin T
(ThT) fluorescence analysis and circular dichroism (CD) spectroscopy.
Results Ion-exchange and affinity chromatography yielded highly pure TAU and Artemin proteins for subsequent
analyses. In addition, we found that heparin efficiently induced TAU fibrillization 48 hours post-incubation, as evidenced
by ThT assay. Importantly, Artemin was observed to effectively block the aggregation of both physiologic- and supra-
physiologic TAU concentrations in a dose-dependent manner, as judged by ThT and CD spectroscopy analyses.
Conclusion Our collective results show, for the first time, that the chaperone Artemin could significantly inhibit
aggregation of the TAU proteins in a dose-dependent manner, and support Artemin as a potential potent blocker of TAU
aggregation in people with AD.
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Affiliation(s)
- Zahra Khosravi
- Department of Biosciences and Biotechnology, Malek Ashtar University of Technology, Tehran, Iran
| | | | - Sharif Moradi
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran.,Department of Developmental Biology, University of Science and Culture, Tehran, Iran
| | - Reza Hassan Sajedi
- Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mehdi Zeinoddini
- Department of Biosciences and Biotechnology, Malek Ashtar University of Technology, Tehran, Iran
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84
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Tau-based therapies in neurodegeneration: opportunities and challenges. Nat Rev Drug Discov 2017; 16:863-883. [DOI: 10.1038/nrd.2017.155] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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85
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Wang C, Saar V, Leung KL, Chen L, Wong G. Human amyloid β peptide and tau co-expression impairs behavior and causes specific gene expression changes in Caenorhabditis elegans. Neurobiol Dis 2017; 109:88-101. [PMID: 28982592 DOI: 10.1016/j.nbd.2017.10.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 09/11/2017] [Accepted: 10/01/2017] [Indexed: 01/20/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by the presence of extracellular amyloid plaques consisting of Amyloid-β peptide (Aβ) aggregates and neurofibrillary tangles formed by aggregation of hyperphosphorylated microtubule-associated protein tau. We generated a novel invertebrate model of AD by crossing Aβ1-42 (strain CL2355) with either pro-aggregating tau (strain BR5270) or anti-aggregating tau (strain BR5271) pan-neuronal expressing transgenic Caenorhabditis elegans. The lifespan and progeny viability of the double transgenic strains were significantly decreased compared with wild type N2 (P<0.0001). In addition, co-expression of these transgenes interfered with neurotransmitter signaling pathways, caused deficits in chemotaxis associative learning, increased protein aggregation visualized by Congo red staining, and increased neuronal loss. Global transcriptomic RNA-seq analysis revealed 248 up- and 805 down-regulated genes in N2 wild type versus Aβ1-42+pro-aggregating tau animals, compared to 293 up- and 295 down-regulated genes in N2 wild type versus Aβ1-42+anti-aggregating tau animals. Gene set enrichment analysis of Aβ1-42+pro-aggregating tau animals uncovered up-regulated annotation clusters UDP-glucuronosyltransferase (5 genes, P<4.2E-4), protein phosphorylation (5 genes, P<2.60E-02), and aging (5 genes, P<8.1E-2) while the down-regulated clusters included nematode cuticle collagen (36 genes, P<1.5E-21). RNA interference of 13 available top up-regulated genes in Aβ1-42+pro-aggregating tau animals revealed that F-box family genes and nep-4 could enhance life span deficits and chemotaxis deficits while Y39G8C.2 (TTBK2) could suppress these behaviors. Comparing the list of regulated genes from C. elegans to the top 60 genes related to human AD confirmed an overlap of 8 genes: patched homolog 1, PTCH1 (ptc-3), the Rab GTPase activating protein, TBC1D16 (tbc-16), the WD repeat and FYVE domain-containing protein 3, WDFY3 (wdfy-3), ADP-ribosylation factor guanine nucleotide exchange factor 2, ARFGEF2 (agef-1), Early B-cell Factor, EBF1 (unc-3), d-amino-acid oxidase, DAO (daao-1), glutamate receptor, metabotropic 1, GRM1 (mgl-2), prolyl 4-hydroxylase subunit alpha 2, P4HA2 (dpy-18 and phy-2). Taken together, our C. elegans double transgenic model provides insight on the fundamental neurobiologic processes underlying human AD and recapitulates selected transcriptomic changes observed in human AD brains.
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Affiliation(s)
- Chenyin Wang
- Faculty of Health Sciences, University of Macau, 999078, Macau
| | - Valeria Saar
- Faculty of Health Sciences, University of Macau, 999078, Macau
| | - Ka Lai Leung
- Faculty of Health Sciences, University of Macau, 999078, Macau
| | - Liang Chen
- Faculty of Health Sciences, University of Macau, 999078, Macau
| | - Garry Wong
- Faculty of Health Sciences, University of Macau, 999078, Macau.
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86
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Rauch JN, Olson SH, Gestwicki JE. Interactions between Microtubule-Associated Protein Tau (MAPT) and Small Molecules. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a024034. [PMID: 27940599 DOI: 10.1101/cshperspect.a024034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Tau aggregation is linked to multiple neurodegenerative disorders that are collectively termed tauopathies. Small molecules are powerful probes of the aggregation process, helping to reveal the key steps and serving as diagnostics and reporters. Moreover, some of these small molecules may have potential as therapeutics. This review details how small molecules and chemical biology have helped to elucidate the mechanisms of tau aggregation and how they are being used to detect and prevent tau aggregation. In addition, we comment on how new insights into tau prions are changing the approach to small molecule discovery.
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Affiliation(s)
- Jennifer N Rauch
- Institute for Neurodegenerative Diseases, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, California 94158
| | - Steven H Olson
- Institute for Neurodegenerative Diseases, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, California 94158
| | - Jason E Gestwicki
- Institute for Neurodegenerative Diseases, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, California 94158
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87
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Kaniyappan S, Chandupatla RR, Mandelkow EM, Mandelkow E. Extracellular low-n oligomers of tau cause selective synaptotoxicity without affecting cell viability. Alzheimers Dement 2017; 13:1270-1291. [PMID: 28528849 DOI: 10.1016/j.jalz.2017.04.002] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 03/27/2017] [Accepted: 04/11/2017] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Tau-mediated toxicity in Alzheimer's disease is thought to operate through low-n oligomers, rather than filamentous aggregates. However, the nature of oligomers and pathways of toxicity are poorly understood. Therefore, we investigated structural and functional aspects of highly purified oligomers of a pro-aggregant tau species. METHODS Purified oligomers of the tau repeat domain were characterized by biophysical and structural methods. Functional aspects were investigated by cellular assays ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay of cell viability, lactate dehydrogenase release assay [for cell toxicity], reactive oxygen species production, and calcium assay), combined with analysis of neuronal dendritic spines exposed to oligomers. RESULTS Purified low-n oligomers are roughly globular, with sizes around 1.6 to 5.4 nm, exhibit an altered conformation, but do not have substantial β-structure. Treatment of primary neurons with oligomers impairs spine morphology and density, accompanied by increased reactive oxygen species and intracellular calcium, but without affecting cell viability (by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay of cell viability and lactate dehydrogenase release assay [for cell toxicity]). DISCUSSION Tau oligomers are toxic to synapses but not lethal to cells.
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Affiliation(s)
- Senthilvelrajan Kaniyappan
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany; MPI for Metabolism Research, Hamburg, Germany.
| | - Ram Reddy Chandupatla
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany; MPI for Metabolism Research, Hamburg, Germany
| | - Eva-Maria Mandelkow
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany; MPI for Metabolism Research, Hamburg, Germany; CAESAR Research Center, Bonn, Germany
| | - Eckhard Mandelkow
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany; MPI for Metabolism Research, Hamburg, Germany; CAESAR Research Center, Bonn, Germany.
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88
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Knowlton WM, Hubert T, Wu Z, Chisholm AD, Jin Y. A Select Subset of Electron Transport Chain Genes Associated with Optic Atrophy Link Mitochondria to Axon Regeneration in Caenorhabditis elegans. Front Neurosci 2017; 11:263. [PMID: 28539870 PMCID: PMC5423972 DOI: 10.3389/fnins.2017.00263] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/24/2017] [Indexed: 12/13/2022] Open
Abstract
The role of mitochondria within injured neurons is an area of active interest since these organelles are vital for the production of cellular energy in the form of ATP. Using mechanosensory neurons of the nematode Caenorhabditis elegans to test regeneration after neuronal injury in vivo, we surveyed genes related to mitochondrial function for effects on axon regrowth after laser axotomy. Genes involved in mitochondrial transport, calcium uptake, mitophagy, or fission and fusion were largely dispensable for axon regrowth, with the exception of eat-3/Opa1. Surprisingly, many genes encoding components of the electron transport chain were dispensable for regrowth, except for the iron-sulfur proteins gas-1, nduf-2.2, nduf-7, and isp-1, and the putative oxidoreductase rad-8. In these mutants, axonal development was essentially normal and axons responded normally to injury by forming regenerative growth cones, but were impaired in subsequent axon extension. Overexpression of nduf-2.2 or isp-1 was sufficient to enhance regrowth, suggesting that mitochondrial function is rate-limiting in axon regeneration. Moreover, loss of function in isp-1 reduced the enhanced regeneration caused by either a gain-of-function mutation in the calcium channel EGL-19 or overexpression of the MAP kinase DLK-1. While the cellular function of RAD-8 remains unclear, our genetic analyses place rad-8 in the same pathway as other electron transport genes in axon regeneration. Unexpectedly, rad-8 regrowth defects were suppressed by altered function in the ubiquinone biosynthesis gene clk-1. Furthermore, we found that inhibition of the mitochondrial unfolded protein response via deletion of atfs-1 suppressed the defective regrowth in nduf-2.2 mutants. Together, our data indicate that while axon regeneration is not significantly affected by general dysfunction of cellular respiration, it is sensitive to the proper functioning of a select subset of electron transport chain genes, or to the cellular adaptations used by neurons under conditions of injury.
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Affiliation(s)
- Wendy M Knowlton
- Section of Neurobiology, Division of Biological Sciences, University of CaliforniaSan Diego, CA, USA
| | - Thomas Hubert
- Section of Neurobiology, Division of Biological Sciences, University of CaliforniaSan Diego, CA, USA
| | - Zilu Wu
- Howard Hughes Medical Institute, University of CaliforniaSan Diego, CA, USA
| | - Andrew D Chisholm
- Section of Neurobiology, Division of Biological Sciences, University of CaliforniaSan Diego, CA, USA
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of CaliforniaSan Diego, CA, USA.,Howard Hughes Medical Institute, University of CaliforniaSan Diego, CA, USA.,Department of Cellular and Molecular Medicine, School of Medicine, University of CaliforniaSan Diego, CA, USA
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89
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Pickhardt M, Biernat J, Hübschmann S, Dennissen FJA, Timm T, Aho A, Mandelkow EM, Mandelkow E. Time course of Tau toxicity and pharmacologic prevention in a cell model of Tauopathy. Neurobiol Aging 2017; 57:47-63. [PMID: 28600952 DOI: 10.1016/j.neurobiolaging.2017.04.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 03/29/2017] [Accepted: 04/23/2017] [Indexed: 10/19/2022]
Abstract
The aggregation of Tau protein is a hallmark of neurodegenerative diseases including Alzheimer's disease. Previously, we generated a cell model of tauopathy based on the 4-repeat domain with the FTDP-17 mutation ΔK280 (Tau4RDΔK) which is expressed in a regulatable fashion (tet-on). The deletion variant ΔK280 is highly amyloidogenic and forms fibrous aggregates in neuroblastoma N2a cells staining with the reporter dye Thioflavin S. The aggregation of Tau4RDΔK is toxic, contrary to wildtype or anti-aggregant variants of the protein. Using a novel approach for monitoring in situ Tau aggregation and toxicity by combination of microscopic analysis with FACS and biochemical analysis of cells enabled the dissection of the aggregating species which cause a time-dependent increase of toxicity. The dominant initiating step is the dimerization of Tau4RDΔK which leads to further aggregation and induces a strong increase in reactive oxygen species (ROS) and cytoplasmic Ca2+ which damage the membranes and cause cell death. Tau-based treatments using Tau aggregation inhibitors reduce both soluble oligomeric and fully aggregated Tau species and decrease their toxicity.
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Affiliation(s)
- Marcus Pickhardt
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany; CAESAR Research Institute, Bonn, Germany
| | - Jacek Biernat
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany; CAESAR Research Institute, Bonn, Germany.
| | - Sabrina Hübschmann
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany; CAESAR Research Institute, Bonn, Germany
| | - Frank J A Dennissen
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany; CAESAR Research Institute, Bonn, Germany
| | - Thomas Timm
- Institute of Biochemistry, Justus-Liebig-University, Giessen, Germany
| | | | - Eva-Maria Mandelkow
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany; CAESAR Research Institute, Bonn, Germany; Max-Planck-Institute for Metabolism Research, Köln, Germany
| | - Eckhard Mandelkow
- DZNE, German Center for Neurodegenerative Diseases, Bonn, Germany; CAESAR Research Institute, Bonn, Germany; Max-Planck-Institute for Metabolism Research, Köln, Germany.
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90
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Chua SW, Cornejo A, van Eersel J, Stevens CH, Vaca I, Cueto M, Kassiou M, Gladbach A, Macmillan A, Lewis L, Whan R, Ittner LM. The Polyphenol Altenusin Inhibits in Vitro Fibrillization of Tau and Reduces Induced Tau Pathology in Primary Neurons. ACS Chem Neurosci 2017; 8:743-751. [PMID: 28067492 DOI: 10.1021/acschemneuro.6b00433] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
In Alzheimer's disease, the microtubule-associated protein tau forms intracellular neurofibrillary tangles (NFTs). A critical step in the formation of NFTs is the conversion of soluble tau into insoluble filaments. Accordingly, a current therapeutic strategy in clinical trials is aimed at preventing tau aggregation. Here, we assessed altenusin, a bioactive polyphenolic compound, for its potential to inhibit tau aggregation. Altenusin inhibits aggregation of tau protein into paired helical filaments in vitro. This was associated with stabilization of tau dimers and other oligomers into globular structures as revealed by atomic force microscopy. Moreover, altenusin reduced tau phosphorylation in cells expressing pathogenic tau, and prevented neuritic tau pathology induced by incubation of primary neurons with tau fibrils. However, treatment of tau transgenic mice did not improve neuropathology and functional deficits. Taken together, altenusin prevents tau fibrillization in vitro and induced tau pathology in neurons.
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Affiliation(s)
- Sook Wern Chua
- Dementia
Research Unit, School of Medical Sciences, Faculty of Medicine, UNSW Australia, Sydney, NSW 2052, Australia
| | - Alberto Cornejo
- Dementia
Research Unit, School of Medical Sciences, Faculty of Medicine, UNSW Australia, Sydney, NSW 2052, Australia
- Faculty
of Medicine, Medical Technology School, University Andrés Bello, Sazié 2315, Santiago, Chile
| | - Janet van Eersel
- Dementia
Research Unit, School of Medical Sciences, Faculty of Medicine, UNSW Australia, Sydney, NSW 2052, Australia
| | - Claire H. Stevens
- Dementia
Research Unit, School of Medical Sciences, Faculty of Medicine, UNSW Australia, Sydney, NSW 2052, Australia
| | - Inmaculada Vaca
- Department
of Chemistry, Faculty of Science, University of Chile, Las Palmeras 3425, Ñuñoa, Santiago, Chile
| | - Mercedes Cueto
- Institute for Natural Products and Agrobiology CSIC, 38206 La Laguna, Tenerife, Spain
| | - Michael Kassiou
- School
of Chemistry and Faculty of Health Sciences, University of Sydney, Sydney, NSW 2006, Australia
| | - Amadeus Gladbach
- Dementia
Research Unit, School of Medical Sciences, Faculty of Medicine, UNSW Australia, Sydney, NSW 2052, Australia
| | - Alex Macmillan
- Biomedical
Imaging Facility, Mark Wainright Analytical Centre, UNSW Australia, Sydney, NSW 2052, Australia
| | - Lev Lewis
- Biomedical
Imaging Facility, Mark Wainright Analytical Centre, UNSW Australia, Sydney, NSW 2052, Australia
| | - Renee Whan
- Biomedical
Imaging Facility, Mark Wainright Analytical Centre, UNSW Australia, Sydney, NSW 2052, Australia
| | - Lars M. Ittner
- Dementia
Research Unit, School of Medical Sciences, Faculty of Medicine, UNSW Australia, Sydney, NSW 2052, Australia
- Neuroscience Research Australia, Sydney, NSW 2031, Australia
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91
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Exploring the power of yeast to model aging and age-related neurodegenerative disorders. Biogerontology 2016; 18:3-34. [PMID: 27804052 DOI: 10.1007/s10522-016-9666-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 10/24/2016] [Indexed: 12/12/2022]
Abstract
Aging is a multifactorial process determined by molecular, cellular and systemic factors and it is well established that advancing age is a leading risk factor for several neurodegenerative diseases. In fact, the close association of aging and neurodegenerative disorders has placed aging as the greatest social and economic challenge of the 21st century, and age-related diseases have also become a key priority for countries worldwide. The growing need to better understand both aging and neurodegenerative processes has led to the development of simple eukaryotic models amenable for mechanistic studies. Saccharomyces cerevisiae has proven to be an unprecedented experimental model to study the fundamental aspects of aging and to decipher the intricacies of neurodegenerative disorders greatly because the molecular mechanisms underlying these processes are evolutionarily conserved from yeast to human. Moreover, yeast offers several methodological advantages allowing a rapid and relatively easy way of establishing gene-protein-function associations. Here we review different aging theories, common cellular pathways driving aging and neurodegenerative diseases and discuss the major contributions of yeast to the state-of-art knowledge in both research fields.
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92
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Imaging of neuronal mitochondria in situ. Curr Opin Neurobiol 2016; 39:152-63. [PMID: 27454347 DOI: 10.1016/j.conb.2016.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 06/04/2016] [Accepted: 06/07/2016] [Indexed: 11/21/2022]
Abstract
Neuronal mitochondria are receiving a rapidly increasing level of attention. This is to a significant part due to the ability to visualize neuronal mitochondria in novel ways, especially in vivo. Such an approach allows studying neuronal mitochondria in an intact tissue context, during different developmental states and in various genetic backgrounds and disease conditions. Hence, in vivo imaging of mitochondria in the nervous system can reveal aspects of the 'mitochondrial life cycle' in neurons that hitherto have remained obscure or could only be inferred indirectly. In this survey of the current literature, we review the new insights that have emerged from studies using mitochondrial imaging in intact neural preparations ranging from worms to mice.
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93
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Generalizing the Concept of Specific Compound Formulation Additives towards Non-Fluorescent Drugs: A Solubilization Study on Potential Anti-Alzheimer-Active Small-Molecule Compounds. Angew Chem Int Ed Engl 2016; 55:8752-6. [DOI: 10.1002/anie.201601147] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Indexed: 11/07/2022]
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94
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Lawatscheck C, Pickhardt M, Wieczorek S, Grafmüller A, Mandelkow E, Börner HG. Erweiterung des Konzeptes spezifischer Wirkstoff-Formulierungsadditive auf nichtfluoreszierende Wirkstoffe: eine Studie zur Solubilisierung potenzieller Anti-Alzheimer-Wirkstoffe. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201601147] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Carmen Lawatscheck
- Humboldt-Universität zu Berlin; Institut für Chemie; Brook-Taylor-Straße 2 12489 Berlin Deutschland
| | - Marcus Pickhardt
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE); Forschungszentrum CAESAR; Ludwig-Erhard-Allee 2 53175 Bonn Deutschland
| | - Sebastian Wieczorek
- Humboldt-Universität zu Berlin; Institut für Chemie; Brook-Taylor-Straße 2 12489 Berlin Deutschland
| | - Andrea Grafmüller
- Max-Planck-Institut für Kolloide und Grenzflächen; Abteilung Theorie & Bio-Systeme; Am Mühlenberg 1 14476 Potsdam Deutschland
| | - Eckhard Mandelkow
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE); Forschungszentrum CAESAR; Ludwig-Erhard-Allee 2 53175 Bonn Deutschland
- Max-Planck-Institut für Stoffwechselforschung; Außenstation Hamburg, c/o DESY; Hamburg Deutschland
| | - Hans G. Börner
- Humboldt-Universität zu Berlin; Institut für Chemie; Brook-Taylor-Straße 2 12489 Berlin Deutschland
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95
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Pir GJ, Choudhary B, Mandelkow E, Mandelkow EM. Tau mutant A152T, a risk factor for FTD/PSP, induces neuronal dysfunction and reduced lifespan independently of aggregation in a C. elegans Tauopathy model. Mol Neurodegener 2016; 11:33. [PMID: 27118310 PMCID: PMC4847334 DOI: 10.1186/s13024-016-0096-1] [Citation(s) in RCA: 32] [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: 12/18/2015] [Accepted: 04/08/2016] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND A certain number of mutations in the Microtubule-Associated Protein Tau (MAPT) gene have been identified in individuals with high risk to develop neurodegenerative diseases, collectively called tauopathies. The mutation A152TMAPT was recently identified in patients diagnosed with frontotemporal spectrum disorders, including Progressive Supranuclear Palsy (PSP), Frontotemporal Dementia (FTD), Corticobasal Degeneration (CBD), and Alzheimer disease (AD). The A152TMAPT mutation is unusual since it lies within the N-terminal region of Tau protein, far outside the repeat domain that is responsible for physiological Tau-microtubule interactions and pathological Tau aggregation. How A152TMAPT causes neurodegeneration remains elusive. RESULTS To understand the pathological consequences of this mutation, here we present a new Caenorhabditis elegans model expressing the mutant A152TMAPT in neurons. While expression of full-length wild-type human tau (Tau(wt), 2N4R) in C. elegans neurons induces a progressive mild uncoordinated locomotion in a dose-dependent manner, mutant tau (Tau(A152T), 2N4R) induces a severe paralysis accompanied by acute neuronal dysfunction. Mutant Tau(A152T) worms display morphological changes in neurons reminiscent of neuronal aging and a shortened life-span. Moreover, mutant A152T overexpressing neurons show mislocalization of pre-synaptic proteins as well as distorted mitochondrial distribution and trafficking. Strikingly, mutant tau-transgenic worms do not accumulate insoluble tau aggregates, although soluble oligomeric tau was detected. In addition, the full-length A152T-tau remains in a pathological conformation that accounts for its toxicity. Moreover, the N-terminal region of tau is not toxic per se, despite the fact that it harbours the A152T mutation, but requires the C-terminal region including the repeat domain to move into the neuronal processes in order to execute the pathology. CONCLUSION In summary, we show that the mutant Tau(A152T) induces neuronal dysfunction, morphological alterations in neurons akin to aging phenotype and reduced life-span independently of aggregation. This comprehensive description of the pathology due to Tau(A152T) opens up multiple possibilities to identify cellular targets involved in the Tau-dependent pathology for a potential therapeutic intervention.
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Affiliation(s)
- Ghulam Jeelani Pir
- German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.
- Max-Planck-Institute for Metabolism Research (Cologne), Hamburg Outstation, c/o DESY, Notkestrasse 85, 22607, Hamburg, Germany.
| | - Bikash Choudhary
- German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
- Max-Planck-Institute for Metabolism Research (Cologne), Hamburg Outstation, c/o DESY, Notkestrasse 85, 22607, Hamburg, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
- Caesar Research Center, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
- Max-Planck-Institute for Metabolism Research (Cologne), Hamburg Outstation, c/o DESY, Notkestrasse 85, 22607, Hamburg, Germany
| | - Eva-Maria Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.
- Caesar Research Center, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.
- Max-Planck-Institute for Metabolism Research (Cologne), Hamburg Outstation, c/o DESY, Notkestrasse 85, 22607, Hamburg, Germany.
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96
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Acetylation mimic of lysine 280 exacerbates human Tau neurotoxicity in vivo. Sci Rep 2016; 6:22685. [PMID: 26940749 PMCID: PMC4778021 DOI: 10.1038/srep22685] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 02/17/2016] [Indexed: 11/08/2022] Open
Abstract
Dysfunction and accumulation of the microtubule-associated human Tau (hTau) protein into intraneuronal aggregates is observed in many neurodegenerative disorders including Alzheimer’s disease (AD). Reversible lysine acetylation has recently emerged as a post-translational modification that may play an important role in the modulation of hTau pathology. Acetylated hTau species have been observed within hTau aggregates in human AD brains and multi-acetylation of hTau in vitro regulates its propensity to aggregate. However, whether lysine acetylation at position 280 (K280) modulates hTau-induced toxicity in vivo is unknown. We generated new Drosophila transgenic models of hTau pathology to evaluate the contribution of K280 acetylation to hTau toxicity, by analysing the respective toxicity of pseudo-acetylated (K280Q) and pseudo-de-acetylated (K280R) mutant forms of hTau. We observed that mis-expression of pseudo-acetylated K280Q-hTau in the adult fly nervous system potently exacerbated fly locomotion defects and photoreceptor neurodegeneration. In addition, modulation of K280 influenced total hTau levels and phosphorylation without changing hTau solubility. Altogether, our results indicate that pseudo-acetylation of the single K280 residue is sufficient to exacerbate hTau neurotoxicity in vivo, suggesting that acetylated K280-hTau species contribute to the pathological events leading to neurodegeneration in AD.
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97
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Morsci NS, Hall DH, Driscoll M, Sheng ZH. Age-Related Phasic Patterns of Mitochondrial Maintenance in Adult Caenorhabditis elegans Neurons. J Neurosci 2016; 36:1373-85. [PMID: 26818523 PMCID: PMC4728731 DOI: 10.1523/jneurosci.2799-15.2016] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 12/11/2015] [Accepted: 12/18/2015] [Indexed: 12/22/2022] Open
Abstract
Aging is associated with cognitive decline and increasing risk of neurodegeneration. Perturbation of mitochondrial function, dynamics, and trafficking are implicated in the pathogenesis of several age-associated neurodegenerative diseases. Despite this fundamental importance, the critical understanding of how organismal aging affects lifetime neuronal mitochondrial maintenance remains unknown, particularly in a physiologically relevant context. To address this issue, we performed a comprehensive in vivo analysis of age-associated changes in mitochondrial morphology, density, trafficking, and stress resistance in individual Caenorhabditis elegans neurons throughout adult life. Adult neurons display three distinct stages of increase, maintenance, and decrease in mitochondrial size and density during adulthood. Mitochondrial trafficking in the distal neuronal processes declines progressively with age starting from early adulthood. In contrast, long-lived daf-2 mutants exhibit delayed age-associated changes in mitochondrial morphology, constant mitochondrial density, and maintained trafficking rates during adulthood. Reduced mitochondrial load at late adulthood correlates with decreased mitochondrial resistance to oxidative stress. Revealing aging-associated changes in neuronal mitochondria in vivo is an essential precedent that will allow future elucidation of the mechanistic causes of mitochondrial aging. Thus, our study establishes the critical foundation for the future analysis of cellular pathways and genetic and pharmacological factors regulating mitochondrial maintenance in aging- and disease-relevant conditions. SIGNIFICANCE STATEMENT Using Caenorhabditis elegans as a model, we address long-standing questions: How does aging affect neuronal mitochondrial morphology, density, trafficking, and oxidative stress resistance? Are these age-related changes amenable to genetic manipulations that slow down the aging process? Our study illustrates that mitochondrial trafficking declines progressively from the first day of adulthood, whereas mitochondrial size, density, and resistance to oxidative stress undergo three distinct stages: increase in early adulthood, maintenance at high levels during mid-adulthood, and decline during late adulthood. Thus, our study characterizes mitochondrial aging profile at the level of a single neuron in its native environment and establishes the critical foundation for the future genetic and pharmacological dissection of factors that influence long-term mitochondrial maintenance in neurons.
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Affiliation(s)
- Natalia S Morsci
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
| | - David H Hall
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, and
| | - Monica Driscoll
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, New Jersey 08855
| | - Zu-Hang Sheng
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892,
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98
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Abstract
Tau is a microtubule-associated protein that has a role in stabilizing neuronal microtubules and thus in promoting axonal outgrowth. Structurally, tau is a natively unfolded protein, is highly soluble and shows little tendency for aggregation. However, tau aggregation is characteristic of several neurodegenerative diseases known as tauopathies. The mechanisms underlying tau pathology and tau-mediated neurodegeneration are debated, but considerable progress has been made in the field of tau research in recent years, including the identification of new physiological roles for tau in the brain. Here, we review the expression, post-translational modifications and functions of tau in physiology and in pathophysiology.
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Affiliation(s)
- Yipeng Wang
- German Center for Neurodegenerative Diseases (DZNE), 53175 Bonn, Germany.,CAESAR Research Center, 53175 Bonn, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), 53175 Bonn, Germany.,CAESAR Research Center, 53175 Bonn, Germany.,Max Planck Institute for Metabolism Research, Hamburg Outstation, c/o DESY, Hamburg, Germany
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99
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Miyasaka T, Xie C, Yoshimura S, Shinzaki Y, Yoshina S, Kage-Nakadai E, Mitani S, Ihara Y. Curcumin improves tau-induced neuronal dysfunction of nematodes. Neurobiol Aging 2015; 39:69-81. [PMID: 26923403 DOI: 10.1016/j.neurobiolaging.2015.11.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 11/09/2015] [Accepted: 11/11/2015] [Indexed: 12/12/2022]
Abstract
Tau is a key protein in the pathogenesis of various neurodegenerative diseases, which are categorized as tauopathies. Because the extent of tau pathologies is closely linked to that of neuronal loss and the clinical symptoms in Alzheimer's disease, anti-tau therapeutics, if any, could be beneficial to a broad spectrum of tauopathies. To learn more about tauopathy, we developed a novel transgenic nematode (Caenorhabditis elegans) model that expresses either wild-type or R406W tau in all the neurons. The wild-type tau-expressing worms exhibited uncoordinated movement (Unc) and neuritic abnormalities. Tau accumulated in abnormal neurites that lost microtubules. Similar abnormalities were found in the worms that expressed low levels of R406W-tau but were not in those expressing comparative levels of wild-type tau. Biochemical studies revealed that tau is aberrantly phosphorylated but forms no detergent-insoluble aggregates. Drug screening performed in these worms identified curcumin, a major phytochemical compound in turmeric, as a compound that reduces not only Unc but also the neuritic abnormalities in both wild-type and R406W tau-expressing worms. Our observations suggest that microtubule stabilization mediates the antitoxicity effect of curcumin. Curcumin is also effective in the worms expressing tau fragment, although it does not prevent the formation of tau-fragment dimers. These data indicate that curcumin improves the tau-induced neuronal dysfunction that is independent of insoluble aggregates of tau.
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Affiliation(s)
- Tomohiro Miyasaka
- Faculty of Medical and Life Sciences, Department of Neuropathology, Doshisha University, Kyotanabe-shi, Kyoto, Japan.
| | - Ce Xie
- Faculty of Medical and Life Sciences, Department of Neuropathology, Doshisha University, Kyotanabe-shi, Kyoto, Japan
| | - Satomi Yoshimura
- Faculty of Medical and Life Sciences, Department of Neuropathology, Doshisha University, Kyotanabe-shi, Kyoto, Japan
| | - Yuki Shinzaki
- Faculty of Medical and Life Sciences, Department of Neuropathology, Doshisha University, Kyotanabe-shi, Kyoto, Japan
| | - Sawako Yoshina
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - Eriko Kage-Nakadai
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Shinjuku-ku, Tokyo, Japan; Advanced Research Institute for Natural Science and Technology, Osaka City University, Sumiyoshi-ku, Osaka, Japan
| | - Shohei Mitani
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - Yasuo Ihara
- Faculty of Medical and Life Sciences, Department of Neuropathology, Doshisha University, Kyotanabe-shi, Kyoto, Japan; Laboratory for Cognition and Aging, Graduate School of Brain Sciences, Doshisha University, Kizugawa-shi, Kyoto, Japan
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100
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Chen X, Barclay JW, Burgoyne RD, Morgan A. Using C. elegans to discover therapeutic compounds for ageing-associated neurodegenerative diseases. Chem Cent J 2015; 9:65. [PMID: 26617668 PMCID: PMC4661952 DOI: 10.1186/s13065-015-0143-y] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 11/15/2015] [Indexed: 12/24/2022] Open
Abstract
Age-associated neurodegenerative disorders such as Alzheimer's disease are a major public health challenge, due to the demographic increase in the proportion of older individuals in society. However, the relatively few currently approved drugs for these conditions provide only symptomatic relief. A major goal of neurodegeneration research is therefore to identify potential new therapeutic compounds that can slow or even reverse disease progression, either by impacting directly on the neurodegenerative process or by activating endogenous physiological neuroprotective mechanisms that decline with ageing. This requires model systems that can recapitulate key features of human neurodegenerative diseases that are also amenable to compound screening approaches. Mammalian models are very powerful, but are prohibitively expensive for high-throughput drug screens. Given the highly conserved neurological pathways between mammals and invertebrates, Caenorhabditis elegans has emerged as a powerful tool for neuroprotective compound screening. Here we describe how C. elegans has been used to model various human ageing-associated neurodegenerative diseases and provide an extensive list of compounds that have therapeutic activity in these worm models and so may have translational potential.
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Affiliation(s)
- Xi Chen
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool, L69 3BX UK ; Centre for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Avenue NE, Grand Rapids, Michigan, MI 49503 USA
| | - Jeff W Barclay
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool, L69 3BX UK
| | - Robert D Burgoyne
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool, L69 3BX UK
| | - Alan Morgan
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool, L69 3BX UK
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