251
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Proteolytic processing of Neuregulin-1. Brain Res Bull 2016; 126:178-182. [PMID: 27393467 DOI: 10.1016/j.brainresbull.2016.07.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 06/28/2016] [Accepted: 07/03/2016] [Indexed: 02/07/2023]
Abstract
Neuregulin-1 (NRG1), known also as heregulin, acetylcholine receptor inducing activity (ARIA), glial growth factor (GGF), or sensory and motor neuron derived factor (SMDF), is a key factor for many developmental processes and in adult brain. All known splice variants contain an epidermal growth factor (EGF)-like domain, which is mediating signaling via receptors of the ErbB family. In particular, NRG1 acts as an essential signaling molecule expressed on the axonal surface, where it signals to Schwann cells throughout development and regulates the thickness of the myelin sheath. NRG1 is required also by other cell types in the nervous system, for instance as an axonal signal released by proprioceptive afferents to induce development of the muscle spindle, and it controls aspects of cortical interneuron development as well as the formation of thalamo-cortical projections. The precursor protein of NRG1 can be activated and released from the membrane through limited proteolysis by the β-Secretase (β-site amyloid precursor protein cleaving enzyme 1, BACE1) which was first identified through its function as the rate limiting enzyme of amyloid-β-peptide (Aβ) production. Aβ is the major component of amyloid plaques in Alzheimer's disease (AD). Due to the hairpin nature of NRG1 type III two membrane-bound stubs with a type 1 and a type 2 orientation are generated by an initial proteolytic cleavage and successive release of the EGF-like domain either by dual cleavage by BACE1 or by ADAM17 (a disintegrin and metalloprotease) which is also called TACE (Tumor Necrosis Factor-α-converting enzyme). The cleavages activate NRG1 to allow juxtacrine or paracrine signaling. The type 1 oriented stub is further cleaved by γ-secretase in the transmembrane domain with a putative role in intracellular domain (ICD) signaling, while the type II oriented stub is cleaved by signal peptidase like proteases (SPPLs). Neuregulin-1 was identified as a major physiological substrate of BACE1 during early postnatal development when similarities in BACE1 KO mice and NRG1 heterozygous mice were discovered. Both display severe hypomyelination of peripheral nerves. Later it was shown with genetic and pharmacological evidence that the developmental effect of type I NRG1 on the formation and the maintenance of muscle spindles is BACE1 dependent. Thus, NRG1 functions in PNS and CNS are likely to set limits to an Alzheimer disease therapy with relatively strong BACE1 inhibition.
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252
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Shi ZM, Han YW, Han XH, Zhang K, Chang YN, Hu ZM, Qi HX, Ting C, Zhen Z, Hong W. Upstream regulators and downstream effectors of NF-κB in Alzheimer's disease. J Neurol Sci 2016; 366:127-134. [DOI: 10.1016/j.jns.2016.05.022] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 05/11/2016] [Accepted: 05/11/2016] [Indexed: 12/09/2022]
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253
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Baranger K, Khrestchatisky M, Rivera S. MT5-MMP, just a new APP processing proteinase in Alzheimer's disease? J Neuroinflammation 2016; 13:167. [PMID: 27349644 PMCID: PMC4924292 DOI: 10.1186/s12974-016-0633-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 06/20/2016] [Indexed: 01/17/2023] Open
Abstract
We have recently identified in a transgenic mouse model of Alzheimer’s disease (AD) membrane-type 5-MMP (MT5-MMP) as a new player in Alzheimer’s pathogenesis, which displays pro-amyloidogenic features and proteolytic processing of amyloid precursor protein (APP). Another group has reported that MT5-MMP processing of APP may release a novel neurotoxic APP fragment. Although MT5-MMP-mediated APP processing appears to be a key pathogenic step, we hypothesize that MT5-MMP may also contribute to AD pathogenesis through complementary mechanisms that involve the activation of pro-inflammatory pathways and/or APP trafficking.
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Beyer I, Rezaei-Ghaleh N, Klafki HW, Jahn O, Haußmann U, Wiltfang J, Zweckstetter M, Knölker HJ. Solid-Phase Synthesis and Characterization of N-Terminally Elongated Aβ-3-x -Peptides. Chemistry 2016; 22:8685-93. [PMID: 27167300 PMCID: PMC5084751 DOI: 10.1002/chem.201600892] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Indexed: 01/24/2023]
Abstract
In addition to the prototypic amyloid-β (Aβ) peptides Aβ1-40 and Aβ1-42 , several Aβ variants differing in their amino and carboxy termini have been described. Synthetic availability of an Aβ variant is often the key to study its role under physiological or pathological conditions. Herein, we report a protocol for the efficient solid-phase peptide synthesis of the N-terminally elongated Aβ-peptides Aβ-3-38 , Aβ-3-40 , and Aβ-3-42 . Biophysical characterization by NMR spectroscopy, CD spectroscopy, an aggregation assay, and electron microscopy revealed that all three peptides were prone to aggregation into amyloid fibrils. Immunoprecipitation, followed by mass spectrometry, indicated that Aβ-3-38 and Aβ-3-40 are generated by transfected cells even in the presence of a tripartite β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitor. The elongated Aβ peptides starting at Val(-3) can be separated from N-terminally-truncated Aβ forms by high-resolution isoelectric-focusing techniques, despite virtually identical isoelectric points. The synthetic Aβ variants and the methods presented here are providing tools to advance our understanding of the potential roles of N-terminally elongated Aβ variants in Alzheimer's disease.
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Affiliation(s)
- Isaak Beyer
- Department Chemie, Technische Universität Dresden, Bergstrasse 66, 01069, Dresden, Germany
| | - Nasrollah Rezaei-Ghaleh
- Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
| | - Hans-Wolfgang Klafki
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Georg-August-Universität, 37075, Göttingen, Germany
| | - Olaf Jahn
- Max Planck Institute for Experimental Medicine, Proteomics Group, 37075, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, University of Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Ute Haußmann
- University of Duisburg-Essen, 45141, Essen, Germany
| | - Jens Wiltfang
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany. ,
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Georg-August-Universität, 37075, Göttingen, Germany. ,
| | - Markus Zweckstetter
- Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, University of Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Hans-Joachim Knölker
- Department Chemie, Technische Universität Dresden, Bergstrasse 66, 01069, Dresden, Germany.
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255
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Lehnert S, Hartmann S, Hessler S, Adelsberger H, Huth T, Alzheimer C. Ion channel regulation by β-secretase BACE1 - enzymatic and non-enzymatic effects beyond Alzheimer's disease. Channels (Austin) 2016; 10:365-378. [PMID: 27253079 DOI: 10.1080/19336950.2016.1196307] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
β-site APP-cleaving enzyme 1 (BACE1) has become infamous for its pivotal role in the pathogenesis of Alzheimer's disease (AD). Consequently, BACE1 represents a prime target in drug development. Despite its detrimental involvement in AD, it should be quite obvious that BACE1 is not primarily present in the brain to drive mental decline. In fact, additional functions have been identified. In this review, we focus on the regulation of ion channels, specifically voltage-gated sodium and KCNQ potassium channels, by BACE1. These studies provide evidence for a highly unexpected feature in the functional repertoire of BACE1. Although capable of cleaving accessory channel subunits, BACE1 exerts many of its physiologically significant effects through direct, non-enzymatic interactions with main channel subunits. We discuss how the underlying mechanisms can be conceived and develop scenarios how the regulation of ion conductances by BACE1 might shape electric activity in the intact and diseased brain and heart.
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Affiliation(s)
- Sandra Lehnert
- a Institute of Physiology and Pathophysiology , Friedrich-Alexander-Universität Erlangen-Nürnberg , Erlangen , Germany
| | - Stephanie Hartmann
- a Institute of Physiology and Pathophysiology , Friedrich-Alexander-Universität Erlangen-Nürnberg , Erlangen , Germany
| | - Sabine Hessler
- b School of Psychology , University of Sussex , Brighton , UK
| | - Helmuth Adelsberger
- c Institute of Neuroscience, Technische Universität München , München , Germany
| | - Tobias Huth
- a Institute of Physiology and Pathophysiology , Friedrich-Alexander-Universität Erlangen-Nürnberg , Erlangen , Germany
| | - Christian Alzheimer
- a Institute of Physiology and Pathophysiology , Friedrich-Alexander-Universität Erlangen-Nürnberg , Erlangen , Germany
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256
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Letronne F, Laumet G, Ayral AM, Chapuis J, Demiautte F, Laga M, Vandenberghe ME, Malmanche N, Leroux F, Eysert F, Sottejeau Y, Chami L, Flaig A, Bauer C, Dourlen P, Lesaffre M, Delay C, Huot L, Dumont J, Werkmeister E, Lafont F, Mendes T, Hansmannel F, Dermaut B, Deprez B, Hérard AS, Dhenain M, Souedet N, Pasquier F, Tulasne D, Berr C, Hauw JJ, Lemoine Y, Amouyel P, Mann D, Déprez R, Checler F, Hot D, Delzescaux T, Gevaert K, Lambert JC. ADAM30 Downregulates APP-Linked Defects Through Cathepsin D Activation in Alzheimer's Disease. EBioMedicine 2016; 9:278-292. [PMID: 27333034 PMCID: PMC4972530 DOI: 10.1016/j.ebiom.2016.06.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 05/31/2016] [Accepted: 06/01/2016] [Indexed: 01/12/2023] Open
Abstract
Although several ADAMs (A disintegrin-like and metalloproteases) have been shown to contribute to the amyloid precursor protein (APP) metabolism, the full spectrum of metalloproteases involved in this metabolism remains to be established. Transcriptomic analyses centred on metalloprotease genes unraveled a 50% decrease in ADAM30 expression that inversely correlates with amyloid load in Alzheimer's disease brains. Accordingly, in vitro down- or up-regulation of ADAM30 expression triggered an increase/decrease in Aβ peptides levels whereas expression of a biologically inactive ADAM30 (ADAM30(mut)) did not affect Aβ secretion. Proteomics/cell-based experiments showed that ADAM30-dependent regulation of APP metabolism required both cathepsin D (CTSD) activation and APP sorting to lysosomes. Accordingly, in Alzheimer-like transgenic mice, neuronal ADAM30 over-expression lowered Aβ42 secretion in neuron primary cultures, soluble Aβ42 and amyloid plaque load levels in the brain and concomitantly enhanced CTSD activity and finally rescued long term potentiation alterations. Our data thus indicate that lowering ADAM30 expression may favor Aβ production, thereby contributing to Alzheimer's disease development.
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Affiliation(s)
- Florent Letronne
- INSERM, U1167, Laboratoire d'Excellence Distalz, F59000 Lille, France; Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France
| | - Geoffroy Laumet
- INSERM, U1167, Laboratoire d'Excellence Distalz, F59000 Lille, France; Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France
| | - Anne-Marie Ayral
- INSERM, U1167, Laboratoire d'Excellence Distalz, F59000 Lille, France; Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France
| | - Julien Chapuis
- INSERM, U1167, Laboratoire d'Excellence Distalz, F59000 Lille, France; Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France
| | - Florie Demiautte
- INSERM, U1167, Laboratoire d'Excellence Distalz, F59000 Lille, France; Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France
| | - Mathias Laga
- Department of Medical Protein Research, VIB, Ghent, Belgium; Department of Biochemistry, Ghent University, Ghent, Belgium
| | - Michel E Vandenberghe
- CEA, DSV, I2BM, MIRCen, Fontenay aux Roses, France; CNRS, UMR 9199, Fontenay aux Roses, France
| | - Nicolas Malmanche
- INSERM, U1167, Laboratoire d'Excellence Distalz, F59000 Lille, France; Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France
| | - Florence Leroux
- Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France; INSERM U1177, Drugs and Molecules for Living Systems, F5900 Lille, France
| | - Fanny Eysert
- INSERM, U1167, Laboratoire d'Excellence Distalz, F59000 Lille, France; Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France
| | - Yoann Sottejeau
- INSERM, U1167, Laboratoire d'Excellence Distalz, F59000 Lille, France; Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France
| | - Linda Chami
- Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275 CNRS, Laboratoire d'Excellence Distalz, Nice, France; Université de Nice-Sophia-Antipolis, Valbonne, France
| | - Amandine Flaig
- INSERM, U1167, Laboratoire d'Excellence Distalz, F59000 Lille, France; Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France
| | - Charlotte Bauer
- Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275 CNRS, Laboratoire d'Excellence Distalz, Nice, France; Université de Nice-Sophia-Antipolis, Valbonne, France
| | - Pierre Dourlen
- INSERM, U1167, Laboratoire d'Excellence Distalz, F59000 Lille, France; Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France
| | - Marie Lesaffre
- Univ. Lille, CNRS, Institut Pasteur de Lille, UMR 8161 - M3T - Mechanisms of Tumorigenesis and Targeted Therapies, F-59000 Lille, France
| | - Charlotte Delay
- INSERM, U1167, Laboratoire d'Excellence Distalz, F59000 Lille, France; Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France
| | - Ludovic Huot
- Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France; Center for Infection and Immunity of Lille, CNRS UMR 8204, INSERM 1019, Lille, France
| | - Julie Dumont
- Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France; INSERM U1177, Drugs and Molecules for Living Systems, F5900 Lille, France
| | | | | | - Tiago Mendes
- INSERM, U1167, Laboratoire d'Excellence Distalz, F59000 Lille, France; Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France
| | - Franck Hansmannel
- INSERM, U954, Vandoeuvre-lès-Nancy, France; Department of Hepato-Gastroenterology, University Hospital of Nancy, Université Henri Poincaré 1, Vandoeuvre-lès-Nancy, France
| | - Bart Dermaut
- INSERM, U1167, Laboratoire d'Excellence Distalz, F59000 Lille, France; Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France
| | - Benoit Deprez
- Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France; INSERM U1177, Drugs and Molecules for Living Systems, F5900 Lille, France
| | - Anne-Sophie Hérard
- CEA, DSV, I2BM, MIRCen, Fontenay aux Roses, France; CNRS, UMR 9199, Fontenay aux Roses, France
| | - Marc Dhenain
- CEA, DSV, I2BM, MIRCen, Fontenay aux Roses, France; CNRS, UMR 9199, Fontenay aux Roses, France
| | - Nicolas Souedet
- CEA, DSV, I2BM, MIRCen, Fontenay aux Roses, France; CNRS, UMR 9199, Fontenay aux Roses, France
| | - Florence Pasquier
- Univ. Lille, Inserm, U1171, - Degenerative & Vascular Cognitive Disorders, Laboratoire d'Excellence Distalz, F-59000 Lille, France; CHR&U, Lille, France
| | - David Tulasne
- Univ. Lille, CNRS, Institut Pasteur de Lille, UMR 8161 - M3T - Mechanisms of Tumorigenesis and Targeted Therapies, F-59000 Lille, France
| | - Claudine Berr
- INSERM, U1061, Université de Montpellier I, Hôpital La Colombière, Montpellier, France
| | - Jean-Jacques Hauw
- APHP-Raymond Escourolle Neuropathology Laboratory, la salpétrière Hospital, Paris, France
| | - Yves Lemoine
- Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France; Center for Infection and Immunity of Lille, CNRS UMR 8204, INSERM 1019, Lille, France
| | - Philippe Amouyel
- INSERM, U1167, Laboratoire d'Excellence Distalz, F59000 Lille, France; Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France; CHR&U, Lille, France
| | - David Mann
- Institute of Brain, Behaviour and Mental Health, University of Manchester, Salford Royal Hospital, Salford, UK
| | - Rebecca Déprez
- Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France; INSERM U1177, Drugs and Molecules for Living Systems, F5900 Lille, France
| | - Frédéric Checler
- Institut de Pharmacologie Moléculaire et Cellulaire, UMR 7275 CNRS, Laboratoire d'Excellence Distalz, Nice, France; Université de Nice-Sophia-Antipolis, Valbonne, France
| | - David Hot
- Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France; Center for Infection and Immunity of Lille, CNRS UMR 8204, INSERM 1019, Lille, France
| | - Thierry Delzescaux
- CEA, DSV, I2BM, MIRCen, Fontenay aux Roses, France; CNRS, UMR 9199, Fontenay aux Roses, France
| | - Kris Gevaert
- Department of Medical Protein Research, VIB, Ghent, Belgium; Department of Biochemistry, Ghent University, Ghent, Belgium
| | - Jean-Charles Lambert
- INSERM, U1167, Laboratoire d'Excellence Distalz, F59000 Lille, France; Institut Pasteur de Lille, F59000 Lille, France; Univ. Lille, F59000 Lille, France.
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257
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Yan R, Fan Q, Zhou J, Vassar R. Inhibiting BACE1 to reverse synaptic dysfunctions in Alzheimer's disease. Neurosci Biobehav Rev 2016; 65:326-40. [PMID: 27044452 PMCID: PMC4856578 DOI: 10.1016/j.neubiorev.2016.03.025] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 03/25/2016] [Accepted: 03/29/2016] [Indexed: 12/21/2022]
Abstract
Over the past two decades, many studies have identified significant contributions of toxic β-amyloid peptides (Aβ) to the etiology of Alzheimer's disease (AD), which is the most common age-dependent neurodegenerative disease. AD is also recognized as a disease of synaptic failure. Aβ, generated by sequential proteolytic cleavages of amyloid precursor protein (APP) by BACE1 and γ-secretase, is one of major culprits that cause this failure. In this review, we summarize current findings on how BACE1-cleaved APP products impact learning and memory through proteins localized on glutamatergic, GABAergic, and dopaminergic synapses. Considering the broad effects of Aβ on all three types of synapses, BACE1 inhibition emerges as a practical approach for ameliorating Aβ-mediated synaptic dysfunctions. Since BACE1 inhibitory drugs are currently in clinical trials, this review also discusses potential complications arising from BACE1 inhibition. We emphasize that the benefits of BACE1 inhibitory drugs will outweigh the concerns.
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Affiliation(s)
- Riqiang Yan
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
| | - Qingyuan Fan
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - John Zhou
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Robert Vassar
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
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258
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Selkoe DJ, Hardy J. The amyloid hypothesis of Alzheimer's disease at 25 years. EMBO Mol Med 2016; 8:595-608. [PMID: 27025652 PMCID: PMC4888851 DOI: 10.15252/emmm.201606210] [Citation(s) in RCA: 3766] [Impact Index Per Article: 470.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 02/24/2016] [Accepted: 03/10/2016] [Indexed: 12/12/2022] Open
Abstract
Despite continuing debate about the amyloid β-protein (or Aβ hypothesis, new lines of evidence from laboratories and clinics worldwide support the concept that an imbalance between production and clearance of Aβ42 and related Aβ peptides is a very early, often initiating factor in Alzheimer's disease (AD). Confirmation that presenilin is the catalytic site of γ-secretase has provided a linchpin: all dominant mutations causing early-onset AD occur either in the substrate (amyloid precursor protein, APP) or the protease (presenilin) of the reaction that generates Aβ. Duplication of the wild-type APP gene in Down's syndrome leads to Aβ deposits in the teens, followed by microgliosis, astrocytosis, and neurofibrillary tangles typical of AD Apolipoprotein E4, which predisposes to AD in > 40% of cases, has been found to impair Aβ clearance from the brain. Soluble oligomers of Aβ42 isolated from AD patients' brains can decrease synapse number, inhibit long-term potentiation, and enhance long-term synaptic depression in rodent hippocampus, and injecting them into healthy rats impairs memory. The human oligomers also induce hyperphosphorylation of tau at AD-relevant epitopes and cause neuritic dystrophy in cultured neurons. Crossing human APP with human tau transgenic mice enhances tau-positive neurotoxicity. In humans, new studies show that low cerebrospinal fluid (CSF) Aβ42 and amyloid-PET positivity precede other AD manifestations by many years. Most importantly, recent trials of three different Aβ antibodies (solanezumab, crenezumab, and aducanumab) have suggested a slowing of cognitive decline in post hoc analyses of mild AD subjects. Although many factors contribute to AD pathogenesis, Aβ dyshomeostasis has emerged as the most extensively validated and compelling therapeutic target.
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Affiliation(s)
- Dennis J Selkoe
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - John Hardy
- Reta Lila Weston Institute and Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
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259
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Cuchillo-Ibañez I, Balmaceda V, Mata-Balaguer T, Lopez-Font I, Sáez-Valero J. Reelin in Alzheimer’s Disease, Increased Levels but Impaired Signaling: When More is Less. J Alzheimers Dis 2016; 52:403-16. [DOI: 10.3233/jad-151193] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Inmaculada Cuchillo-Ibañez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Valeria Balmaceda
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Trinidad Mata-Balaguer
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Inmaculada Lopez-Font
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Javier Sáez-Valero
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d’Alacant, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
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260
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Kim BM, You MH, Chen CH, Suh J, Tanzi RE, Ho Lee T. Inhibition of death-associated protein kinase 1 attenuates the phosphorylation and amyloidogenic processing of amyloid precursor protein. Hum Mol Genet 2016; 25:2498-2513. [PMID: 27094130 DOI: 10.1093/hmg/ddw114] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Revised: 04/05/2016] [Accepted: 04/11/2016] [Indexed: 12/19/2022] Open
Abstract
Extracellular deposition of amyloid-beta (Aβ) peptide, a metabolite of sequential cleavage of amyloid precursor protein (APP), is a critical step in the pathogenesis of Alzheimer's disease (AD). While death-associated protein kinase 1 (DAPK1) is highly expressed in AD brains and its genetic variants are linked to AD risk, little is known about the impact of DAPK1 on APP metabolism and Aβ generation. In this study, we demonstrated a novel effect of DAPK1 in the regulation of APP processing using cell culture and mouse models. DAPK1, but not its kinase deficient mutant (K42A), significantly increased human Aβ secretion in neuronal cell culture models. Moreover, knockdown of DAPK1 expression or inhibition of DAPK1 catalytic activity significantly decreased Aβ secretion. Furthermore, DAPK1, but not K42A, triggered Thr668 phosphorylation of APP, which may initiate and facilitate amyloidogenic APP processing leading to the generation of Aβ. In Tg2576 APPswe-overexpressing mice, knockout of DAPK1 shifted APP processing toward non-amyloidogenic pathway and decreased Aβ generation. Finally, in AD brains, elevated DAPK1 levels showed co-relation with the increase of APP phosphorylation. Combined together, these results suggest that DAPK1 promotes the phosphorylation and amyloidogenic processing of APP, and that may serve a potential therapeutic target for AD.
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Affiliation(s)
- Byeong Mo Kim
- Division of Gerontology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.,Severance Integrative Research Institute for Cerebral & Cardiovascular Diseases, Yonsei University College of Medicine, Seoul 120-752, Republic of Korea
| | - Mi-Hyeon You
- Division of Gerontology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Chun-Hau Chen
- Division of Hematology/Oncology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Jaehong Suh
- Genetics and Aging Research Unit, MassGeneral Institute of Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, MassGeneral Institute of Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | - Tae Ho Lee
- Division of Gerontology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
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261
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Ohno M. Alzheimer's therapy targeting the β-secretase enzyme BACE1: Benefits and potential limitations from the perspective of animal model studies. Brain Res Bull 2016; 126:183-198. [PMID: 27093940 DOI: 10.1016/j.brainresbull.2016.04.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/05/2016] [Accepted: 04/10/2016] [Indexed: 01/18/2023]
Abstract
Accumulating evidence points to the amyloid-β (Aβ) peptide as the culprit in the pathogenesis of Alzheimer's disease (AD). β-Site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1) is a protease that is responsible for initiating Aβ production. Although precise mechanisms that trigger Aβ accumulation remain unclear, BACE1 inhibition undoubtedly represents an important intervention that may prevent and/or cure AD. Remarkably, animal model studies with knockouts, virus-delivered small interfering RNAs, immunization and bioavailable small-molecule agents that specifically inhibit BACE1 activity strongly support the idea for the therapeutic BACE1 inhibition. Meanwhile, a growing number of BACE1 substrates besides APP uncover new physiological roles of this protease, raising some concern regarding the safety of BACE1 inhibition. Here, I review recent progress in preclinical studies that have evaluated the efficacies and potential limitations of genetic/pharmacological inhibition of BACE1, with special focus on AD-associated phenotypes including synaptic dysfunction, neuron loss and memory deficits in animal models.
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Affiliation(s)
- Masuo Ohno
- Center for Dementia Research, Nathan Kline Institute, 140 Old Orangeburg Road, Orangeburg, NY 10962, USA; Departments of Psychiatry, New York University Langone Medical Center, New York, NY 10016, USA.
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262
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Sala Frigerio C, De Strooper B. Alzheimer's Disease Mechanisms and Emerging Roads to Novel Therapeutics. Annu Rev Neurosci 2016; 39:57-79. [PMID: 27050320 DOI: 10.1146/annurev-neuro-070815-014015] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ten years of remarkable progress in understanding the fundamental biochemistry of Alzheimer's disease have been followed by ten years of remarkable and increasing clinical insight into the natural progression of the disorder. The concept of a long, intermediary, prodromal phase between the first appearance of amyloid plaques and tangles and the manifestation of dementia is now well established. The major challenge for the next decade is to chart the many cellular processes that underlie this phase and link the biochemical alterations to the clinical manifestation of Alzheimer's disease. We discuss here how genetics, new cell culture systems, and improved animal models will fuel this work. We anticipate that the resulting novel insights will provide a basis for further drug development for this terrible disease.
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Affiliation(s)
- Carlo Sala Frigerio
- VIB Center for the Biology of Disease, Vlaams Instituut voor Biotechnologie, Leuven 3000, Belgium; , .,Center for Human Genetics, KU Leuven, Leuven 3000, Belgium.,Leuven Research Institute for Neuroscience & Disease (LIND), KU Leuven, Leuven 3000, Belgium
| | - Bart De Strooper
- VIB Center for the Biology of Disease, Vlaams Instituut voor Biotechnologie, Leuven 3000, Belgium; , .,Center for Human Genetics, KU Leuven, Leuven 3000, Belgium.,Leuven Research Institute for Neuroscience & Disease (LIND), KU Leuven, Leuven 3000, Belgium.,Institute of Neurology, University College London, WC1N 3BG London, United Kingdom
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263
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Cappai R. 'From past to future' - deciphering the molecular basis of Alzheimer's disease through the pages of the Journal of Neurochemistry. J Neurochem 2016; 139 Suppl 2:215-223. [PMID: 26996965 DOI: 10.1111/jnc.13546] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 12/31/2015] [Accepted: 01/19/2016] [Indexed: 12/28/2022]
Abstract
The Journal of Neurochemistry has made significant contributions to unraveling the molecular basis for Alzheimer's disease during its 60-year history. To mark its 60th anniversary, this review describes the association between the journal and Alzheimer's disease research - from the early years when Alzheimer's disease was a minor topic in the journal through to the molecular era in the mid-1980s. This coincided with a number of the highly cited Alzheimer's disease studies which described fundamental aspects of the neurochemistry of Alzheimer's disease and encompassed the themes of oxidative stress and post-translational modifications, cholinergic system, tau, purification of Aβ, defining the Aβ toxic species, mechanism of amyloid precursor protein processing, and the development of diagnostics and therapeutics. The Journal of Neurochemistry has made significant contributions toward unraveling the molecular, cellular and pathological basis of Alzheimer's disease through its 60 years. This article is part of the 60th Anniversary special issue.
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Affiliation(s)
- Roberto Cappai
- Department of Pathology, The University of Melbourne, Melbourne, Victoria, Australia.
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264
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BACE1 Physiological Functions May Limit Its Use as Therapeutic Target for Alzheimer's Disease. Trends Neurosci 2016; 39:158-169. [DOI: 10.1016/j.tins.2016.01.003] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 01/07/2016] [Accepted: 01/08/2016] [Indexed: 01/21/2023]
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265
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APP Receptor? To Be or Not To Be. Trends Pharmacol Sci 2016; 37:390-411. [PMID: 26837733 DOI: 10.1016/j.tips.2016.01.005] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 01/07/2016] [Accepted: 01/11/2016] [Indexed: 11/22/2022]
Abstract
Amyloid precursor protein (APP) and its metabolites play a key role in Alzheimer's disease pathogenesis. The idea that APP may function as a receptor has gained momentum based on its structural similarities to type I transmembrane receptors and the identification of putative APP ligands. We review the recent experimental evidence in support of this notion and discuss how this concept is viewed in the field. Specifically, we focus on the structural and functional characteristics of APP as a cell surface receptor, and on its interaction with adaptors and signaling proteins. We also address the importance of APP function as a receptor in Alzheimer's disease etiology and discuss how this function might be potentially important for the development of novel therapeutic approaches.
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266
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267
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Eisele YS, Duyckaerts C. Propagation of Aß pathology: hypotheses, discoveries, and yet unresolved questions from experimental and human brain studies. Acta Neuropathol 2016; 131:5-25. [PMID: 26715565 DOI: 10.1007/s00401-015-1516-y] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 11/29/2015] [Accepted: 11/30/2015] [Indexed: 12/11/2022]
Abstract
In brains of patients with Alzheimer's disease (AD), Aβ peptides accumulate in parenchyma and, almost invariably, also in the vascular walls. Although Aβ aggregation is, by definition, present in AD, its impact is only incompletely understood. It occurs in a stereotypical spatiotemporal distribution within neuronal networks in the course of the disease. This suggests a role for synaptic connections in propagating Aβ pathology, and possibly of axonal transport in an antero- or retrograde way-although, there is also evidence for passive, extracellular diffusion. Striking, in AD, is the conjunction of tau and Aβ pathology. Tau pathology in the cell body of neurons precedes Aβ deposition in their synaptic endings in several circuits such as the entorhino-dentate, cortico-striatal or subiculo-mammillary connections. However, genetic evidence suggests that Aβ accumulation is the first step in AD pathogenesis. To model the complexity and consequences of Aβ aggregation in vivo, various transgenic (tg) rodents have been generated. In rodents tg for the human Aβ precursor protein, focal injections of preformed Aβ aggregates can induce Aβ deposits in the vicinity of the injection site, and over time in more distant regions of the brain. This suggests that Aβ shares with α-synuclein, tau and other proteins the property to misfold and aggregate homotypic molecules. We propose to group those proteins under the term "propagons". Propagons may lack the infectivity of prions. We review findings from neuropathological examinations of human brains in different stages of AD and from studies in rodent models of Aβ aggregation and discuss putative mechanisms underlying the initiation and spread of Aβ pathology.
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Affiliation(s)
- Yvonne S Eisele
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, 92037, USA.
| | - Charles Duyckaerts
- Laboratoire de Neuropathologie Raymond-Escourolle, Hopital de la Pitie-Salpetriere, 47, boulevard de l'Hopital, 75651, Paris Cedex 13, France.
- ICM, equipe Alzheimer-Prion, 47, boulevard de l'Hopital, 750713, Paris, France.
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268
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Zuo C, Tang S, Si YY, Wang ZA, Tian CL, Zheng JS. Efficient synthesis of longer Aβ peptides via removable backbone modification. Org Biomol Chem 2016; 14:5012-8. [DOI: 10.1039/c6ob00712k] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This paper describes a new method for the efficient chemical synthesis of longer Aβ peptides with the combination of the RBM strategy and native chemical ligation.
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Affiliation(s)
- Chao Zuo
- High Magnetic Field Laboratory
- Chinese Academy of Sciences
- School of Life Sciences
- University of Science and Technology of China
- Hefei 230026
| | - Shan Tang
- Department of Chemistry
- Tsinghua University
- Beijing 100084
- China
| | - Yan-Yan Si
- Department of Chemistry
- Tsinghua University
- Beijing 100084
- China
| | - Zhipeng A. Wang
- Department of Chemistry
- Tsinghua University
- Beijing 100084
- China
| | - Chang-Lin Tian
- High Magnetic Field Laboratory
- Chinese Academy of Sciences
- School of Life Sciences
- University of Science and Technology of China
- Hefei 230026
| | - Ji-Shen Zheng
- High Magnetic Field Laboratory
- Chinese Academy of Sciences
- School of Life Sciences
- University of Science and Technology of China
- Hefei 230026
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269
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Hamm V, Héraud C, Cassel JC, Mathis C, Goutagny R. Precocious Alterations of Brain Oscillatory Activity in Alzheimer's Disease: A Window of Opportunity for Early Diagnosis and Treatment. Front Cell Neurosci 2015; 9:491. [PMID: 26733816 PMCID: PMC4685112 DOI: 10.3389/fncel.2015.00491] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 12/04/2015] [Indexed: 12/31/2022] Open
Abstract
Alzheimer's disease (AD) is the most common form of neurodegenerative dementia accounting for 50-80% of all age-related dementia. This pathology is characterized by the progressive and irreversible alteration of cognitive functions, such as memory, leading inexorably to the loss of autonomy for patients with AD. The pathology is linked with aging and occurs most commonly around 65 years old. Its prevalence (5% over 65 years of age and 20% after 80 years) constitutes an economic and social burden for AD patients and their family. At the present, there is still no cure for AD, actual treatments being moderately effective only in early stages of the pathology. A lot of efforts have been deployed with the aim of defining new AD biomarkers. Successful early detection of mild cognitive impairment (MCI) linked to AD requires the identification of biomarkers capable of distinguishing individuals with early stages of AD from other pathologies impacting cognition such as depression. In this article, we will review recent evidence suggesting that electroencephalographic (EEG) recordings, coupled with behavioral assessments, could be a useful approach and easily implementable for a precocious detection of AD.
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Affiliation(s)
- Valentine Hamm
- Centre National de la Recherche Scientifique UMR 7364, Laboratoire de Neurosciences Cognitives et AdaptativesStrasbourg, France; Université de Strasbourg, Neuropôle de StrasbourgStrasbourg, France
| | - Céline Héraud
- Centre National de la Recherche Scientifique UMR 7364, Laboratoire de Neurosciences Cognitives et AdaptativesStrasbourg, France; Université de Strasbourg, Neuropôle de StrasbourgStrasbourg, France
| | - Jean-Christophe Cassel
- Centre National de la Recherche Scientifique UMR 7364, Laboratoire de Neurosciences Cognitives et AdaptativesStrasbourg, France; Université de Strasbourg, Neuropôle de StrasbourgStrasbourg, France
| | - Chantal Mathis
- Centre National de la Recherche Scientifique UMR 7364, Laboratoire de Neurosciences Cognitives et AdaptativesStrasbourg, France; Université de Strasbourg, Neuropôle de StrasbourgStrasbourg, France
| | - Romain Goutagny
- Centre National de la Recherche Scientifique UMR 7364, Laboratoire de Neurosciences Cognitives et AdaptativesStrasbourg, France; Université de Strasbourg, Neuropôle de StrasbourgStrasbourg, France
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270
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Onos KD, Sukoff Rizzo SJ, Howell GR, Sasner M. Toward more predictive genetic mouse models of Alzheimer's disease. Brain Res Bull 2015; 122:1-11. [PMID: 26708939 DOI: 10.1016/j.brainresbull.2015.12.003] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 12/09/2015] [Accepted: 12/14/2015] [Indexed: 01/14/2023]
Abstract
Genetic mouse models for Alzheimer's disease (AD) have been widely used to understand aspects of the biology of the disease, but have had limited success in translating these findings to the clinic. In this review, we discuss the benefits and limitations of existing genetic models and recent advances in technologies (including high throughput sequencing and genome editing) that promise more predictive models. We summarize widely used biomarkers and behavioral tests for mouse models of AD and highlight best practices that will maximize translatability of preclinical findings.
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Affiliation(s)
| | | | - Gareth R Howell
- The Jackson Laboratory, Bar Harbor, ME, United States; Graduate Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University, 136 Harrison Avenue, Boston, MA, United States.
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271
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Ghosh A, Giese KP. Calcium/calmodulin-dependent kinase II and Alzheimer's disease. Mol Brain 2015; 8:78. [PMID: 26603284 PMCID: PMC4657223 DOI: 10.1186/s13041-015-0166-2] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 11/13/2015] [Indexed: 11/10/2022] Open
Abstract
CaMKII is a remarkably complex protein kinase, known to have a fundamental role in synaptic plasticity and memory formation. Further, CaMKII has also been suggested to be a tau kinase. CaMKII dysregulation may therefore be a modulator of toxicity in Alzheimer's disease, a dementia characterised by aberrant calcium signalling, synapse and neuronal loss, and impaired memory. Here, we first examine the evidence for CaMKII dysregulation in Alzheimer's patients and draw parallels to findings in disease models which recapitulate key aspects of the disease. We then put forward the hypothesis that these changes critically contribute to neurodegeneration and memory impairment in Alzheimer's disease.
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Affiliation(s)
- Anshua Ghosh
- Maurice Wohl Clinical Neuroscience Institute, King's College London, 5 Cutcombe Road, London, SE5 9RT, UK.
| | - Karl Peter Giese
- Maurice Wohl Clinical Neuroscience Institute, King's College London, 5 Cutcombe Road, London, SE5 9RT, UK.
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272
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Fanutza T, Del Prete D, Ford MJ, Castillo PE, D’Adamio L. APP and APLP2 interact with the synaptic release machinery and facilitate transmitter release at hippocampal synapses. eLife 2015; 4:e09743. [PMID: 26551565 PMCID: PMC4755753 DOI: 10.7554/elife.09743] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 11/08/2015] [Indexed: 12/16/2022] Open
Abstract
The amyloid precursor protein (APP), whose mutations cause familial Alzheimer's disease, interacts with the synaptic release machinery, suggesting a role in neurotransmission. Here we mapped this interaction to the NH2-terminal region of the APP intracellular domain. A peptide encompassing this binding domain -named JCasp- is naturally produced by a γ-secretase/caspase double-cut of APP. JCasp interferes with the APP-presynaptic proteins interaction and, if linked to a cell-penetrating peptide, reduces glutamate release in acute hippocampal slices from wild-type but not APP deficient mice, indicating that JCasp inhibits APP function.The APP-like protein-2 (APLP2) also binds the synaptic release machinery. Deletion of APP and APLP2 produces synaptic deficits similar to those caused by JCasp. Our data support the notion that APP and APLP2 facilitate transmitter release, likely through the interaction with the neurotransmitter release machinery. Given the link of APP to Alzheimer's disease, alterations of this synaptic role of APP could contribute to dementia.
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Affiliation(s)
- Tomas Fanutza
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, New York, United States
| | - Dolores Del Prete
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, New York, United States
| | | | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, United States
| | - Luciano D’Adamio
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, New York, United States
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273
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Kokawa A, Ishihara S, Fujiwara H, Nobuhara M, Iwata M, Ihara Y, Funamoto S. The A673T mutation in the amyloid precursor protein reduces the production of β-amyloid protein from its β-carboxyl terminal fragment in cells. Acta Neuropathol Commun 2015; 3:66. [PMID: 26531305 PMCID: PMC4632685 DOI: 10.1186/s40478-015-0247-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 10/22/2015] [Indexed: 12/16/2022] Open
Abstract
Introduction The A673T mutation in the amyloid precursor protein (APP) protects against Alzheimer’s disease by reducing β-amyloid protein (Aβ) production. This mutation reduced the release of the soluble APP fragment (sAPPβ), which is processed by β-secretase, suggesting a concomitant decrease in the β-carboxyl fragment of APP (C99), which is a direct substrate of γ-secretase for Aβ production. However, it remains controversial whether the level of C99 is significantly reduced in cells expressing APP that carry A673T as the cause of reduced Aβ production. Here, we investigated the effect of the A673T mutation in C99 on γ-cleavage in cells. Results We found that the level of C99 in cells expressing APP A673T was indistinctive of that observed in cells expressing wild-type APP, although the release of sAPPβ was significantly reduced in the APP A673T cells. In addition, our reconstituted β-secretase assay demonstrated no significant difference in β-cleavage on an APP fragment carrying the A673T mutation compared with the wild-type fragment. Importantly, cells expressing C99 containing the A673T mutation (C99 A2T; in accordance with the Aβ numbering) produced roughly half the level of Aβ compared with the wild-type C99, suggesting that the C99 A2T is an insufficient substrate of γ-secretase in cells. A cell-free γ-secretase assay revealed that Aβ production from the microsomal fraction of cells expressing C99 A2T was diminished. A sucrose gradient centrifugation analysis indicated that the levels of the C99 A2T that was codistributed with γ-secretase components in the raft fractions were reduced significantly. Conclusions Our data indicate that the A673T mutation in APP alters the release of sAPPβ, but not the C99 level, and that the C99 A2T is an inefficient substrate for γ-secretase in cell-based assay. Electronic supplementary material The online version of this article (doi:10.1186/s40478-015-0247-6) contains supplementary material, which is available to authorized users.
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274
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The alpha secretase ADAM10: A metalloprotease with multiple functions in the brain. Prog Neurobiol 2015; 135:1-20. [PMID: 26522965 DOI: 10.1016/j.pneurobio.2015.10.003] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/23/2015] [Accepted: 10/26/2015] [Indexed: 01/07/2023]
Abstract
Proteins belonging to the 'A Disintegrin And Metalloproteinase' (ADAM) family are membrane-anchored proteases that are able to cleave the extracellular domains of several membrane-bound proteins in a process known as 'ectodomain shedding'. In the central nervous system, ADAM10 has attracted the most attention, since it was described as the amyloid precursor protein α-secretase over ten years ago. Despite the excitement over the potential of ADAM10 as a novel drug target in Alzheimer disease, the physiological functions of ADAM10 in the brain are not yet well understood. This is largely because of the embryonic lethality of ADAM10-deficient mice, which results from the loss of cleavage and signaling of the Notch receptor, another ADAM10 substrate. However, the recent generation of conditional ADAM10-deficient mice and the identification of further ADAM10 substrates in the brain has revealed surprisingly numerous and fundamental functions of ADAM10 in the development of the embryonic brain and also in the homeostasis of adult neuronal networks. Mechanistically, ADAM10 controls these functions by utilizing unique postsynaptic substrates in the central nervous system, in particular synaptic cell adhesion molecules, such as neuroligin-1, N-cadherin, NCAM, Ephrin A2 and A5. Consequently, a dysregulation of ADAM10 activity is linked to psychiatric and neurological diseases, such as epilepsy, fragile X syndrome and Huntington disease. This review highlights the recent progress in understanding the substrates and function as well as the regulation and cell biology of ADAM10 in the central nervous system and discusses the value of ADAM10 as a drug target in brain diseases.
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275
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Tyan SH, Koo EH. New tricks from an old dog: Another synaptotoxic fragment from APP. Cell Res 2015; 25:1185-6. [PMID: 26503171 DOI: 10.1038/cr.2015.125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
In a surprising twist, a hitherto unrecognized cleavage of the amyloid precursor protein (APP) by η-secretase, followed by α- or β-secretase cleavage releases a novel APP proteolytic fragment, Aη, which causes synaptic injury.
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Affiliation(s)
- Sheue-Houy Tyan
- Department of Medicine, National University of Singapore, Singapore
| | - Edward H Koo
- Department of Medicine, National University of Singapore, Singapore.,Department of Neurosciences, University of California San Diego, La Jolla, USA
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276
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Aguzzi A, Lakkaraju AKK. Cell Biology of Prions and Prionoids: A Status Report. Trends Cell Biol 2015; 26:40-51. [PMID: 26455408 DOI: 10.1016/j.tcb.2015.08.007] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 08/08/2015] [Accepted: 08/24/2015] [Indexed: 11/18/2022]
Abstract
The coalescence of proteins into highly ordered aggregates is a hallmark of protein misfolding disorders (PMDs), which, when affecting the central nervous system, lead to progressive neurodegeneration. Although the chemical identity and the topology of each culprit protein are unique, the principles governing aggregation and propagation are strikingly stereotypical. It is now clear that such protein aggregates can spread from cell to cell and eventually affect entire organ systems - similarly to prion diseases. However, because most aggregates are not found to transmit between individuals, they are not infectious sensu strictiori. Therefore, they are not identical to prions and we prefer to define them as 'prionoids'. Here we review recent advances in understanding the toxicity of protein aggregation affecting the brain.
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Affiliation(s)
- Adriano Aguzzi
- Institute of Neuropathology, University of Zürich, CH-8091 Zürich, Switzerland.
| | - Asvin K K Lakkaraju
- Institute of Neuropathology, University of Zürich, CH-8091 Zürich, Switzerland.
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