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Kim EH, Lee WS, Lee JH, Kwon DR. Microcurrent therapy as the nonpharmacological new protocol against Alzheimer's disease. Front Aging Neurosci 2024; 16:1344072. [PMID: 38304741 PMCID: PMC10833500 DOI: 10.3389/fnagi.2024.1344072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 01/09/2024] [Indexed: 02/03/2024] Open
Abstract
Introduction Alzheimer's disease (AD) poses an increasing global health challenge and is marked by gradual cognitive deterioration, memory impairment, and neuroinflammation. Innovative therapeutic approaches as non-pharmacological protocol are urgently needed with side effect risk of drugs. Microcurrent therapy, a non-invasive modality involving low-level electrical currents, has emerged as a potential solution to address AD's complex pathogenesis. This study investigates the optimal application of microcurrent therapy as a clinical protocol for AD, utilizing a comprehensive approach that integrates behavioral assessments and neuroinflammation evaluation in a mouse model of dementia. Methods and results The results reveal that microcurrent therapy holds promise in ameliorating memory impairment and reducing neuroinflammation in AD. Behavioral assessments, including the Novel Object Recognition Test (NOR) and Radial Arm Maze Test (RAM), demonstrated improved cognitive function following microcurrent therapy. Furthermore, microcurrent therapy inhibited expression of neuroinflammatory proteins, including ionized calcium binding adaptor molecule 1 (Iba1), and glial fibrillary acidic protein (GFAP) in current-treated group. Mechanistic insights suggest that microcurrent therapy may modulate neuroinflammation through the regulation of MAPK signaling pathways. Conclusion This study emphasizes the prospect of microcurrent therapy as a safe and efficacious non-pharmacological strategy for Alzheimer's disease (AD), providing optimism to the countless individuals impacted by this debilitating ailment. These results contribute to the developments of an innovative clinical protocol for AD and recovery from neurological injury, underscoring the significance of investigating unconventional therapeutic approaches for addressing this complex condition.
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Affiliation(s)
- Eun Ho Kim
- Department of Biochemistry, School of Medicine, Daegu Catholic University, Daegu, Republic of Korea
| | - Won Seok Lee
- Department of Biochemistry, School of Medicine, Daegu Catholic University, Daegu, Republic of Korea
| | - Jae Hee Lee
- Department of Rehabilitation Medicine, School of Medicine, Daegu Catholic University, Daegu, Republic of Korea
| | - Dong Rak Kwon
- Department of Rehabilitation Medicine, School of Medicine, Daegu Catholic University, Daegu, Republic of Korea
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2
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Schilling S, Pradhan A, Heesch A, Helbig A, Blennow K, Koch C, Bertgen L, Koo EH, Brinkmalm G, Zetterberg H, Kins S, Eggert S. Differential effects of familial Alzheimer's disease-causing mutations on amyloid precursor protein (APP) trafficking, proteolytic conversion, and synaptogenic activity. Acta Neuropathol Commun 2023; 11:87. [PMID: 37259128 DOI: 10.1186/s40478-023-01577-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 05/04/2023] [Indexed: 06/02/2023] Open
Abstract
The amyloid precursor protein (APP) is a key player in Alzheimer`s disease (AD) and the precursor of the Aβ peptide, which is generated by consecutive cleavages of β- and γ-secretases. Familial Alzheimer's disease (FAD) describes a hereditary subgroup of AD that represents a low percentage of AD cases with an early onset of the disease. Different APP FAD mutations are thought to have qualitatively different effects on its proteolytic conversion. However, few studies have explored the pathogenic and putative physiological differences in more detail. Here, we compared different FAD mutations, located at the β- (Swedish), α- (Flemish, Arctic, Iowa) or γ-secretase (Iberian) cleavage sites. We examined heterologous expression of APP WT and FAD mutants in non-neuronal cells and their impact on presynaptic differentiation in contacting axons of co-cultured neurons. To decipher the underlying molecular mechanism, we tested the subcellular localization, the endocytosis rate and the proteolytic processing in detail by immunoprecipitation-mass spectrometry. Interestingly, we found that only the Iberian mutation showed altered synaptogenic function. Furthermore, the APP Iowa mutant shows significantly decreased α-secretase processing which is in line with our results that APP carrying the Iowa mutation was significantly increased in early endosomes. However, most interestingly, immunoprecipitation-mass spectrometry analysis revealed that the amino acid substitutions of APP FAD mutants have a decisive impact on their processing reflected in altered Aβ profiles. Importantly, N-terminally truncated Aβ peptides starting at position 5 were detected preferentially for APP Flemish, Arctic, and Iowa mutants containing amino acid substitutions around the α-secretase cleavage site. The strongest change in the ratio of Aβ40/Aβ42 was observed for the Iberian mutation while APP Swedish showed a substantial increase in Aβ1-17 peptides. Together, our data indicate that familial AD mutations located at the α-, β-, and γ-secretase cleavage sites show considerable differences in the underlying pathogenic mechanisms.
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Affiliation(s)
- Sandra Schilling
- Department of Human Biology and Human Genetics, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Ajay Pradhan
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
| | - Amelie Heesch
- Department of Human Biology and Human Genetics, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Andrea Helbig
- Department of Human Biology and Human Genetics, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
| | - Christian Koch
- Department of Human Biology and Human Genetics, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Lea Bertgen
- Department of Human Biology and Human Genetics, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Edward H Koo
- San Diego (UCSD), Department of Neuroscience, University of California, La Jolla, CA, 92093-0662, USA
| | - Gunnar Brinkmalm
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
- UK Dementia Research Institute at UCL, London, UK
- Hong Kong Center for Neurodegenerative Diseases, Clear Water Bay, Hong Kong, China
| | - Stefan Kins
- Department of Human Biology and Human Genetics, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Simone Eggert
- Department of Human Biology and Human Genetics, University of Kaiserslautern, 67663, Kaiserslautern, Germany.
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, City-Campus, Hermann-Rein-Str. 3, 37075, Göttingen, Germany.
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3
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Ulku I, Liebsch F, Akerman SC, Schulz JF, Kulic L, Hock C, Pietrzik C, Di Spiezio A, Thinakaran G, Saftig P, Multhaup G. Mechanisms of amyloid-β34 generation indicate a pivotal role for BACE1 in amyloid homeostasis. Sci Rep 2023; 13:2216. [PMID: 36750595 PMCID: PMC9905473 DOI: 10.1038/s41598-023-28846-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 01/25/2023] [Indexed: 02/09/2023] Open
Abstract
The beta‑site amyloid precursor protein (APP) cleaving enzyme (BACE1) was discovered due to its "amyloidogenic" activity which contributes to the production of amyloid-beta (Aβ) peptides. However, BACE1 also possesses an "amyloidolytic" activity, whereby it degrades longer Aβ peptides into a non‑toxic Aβ34 intermediate. Here, we examine conditions that shift the equilibrium between BACE1 amyloidogenic and amyloidolytic activities by altering BACE1/APP ratios. In Alzheimer disease brain tissue, we found an association between elevated levels of BACE1 and Aβ34. In mice, the deletion of one BACE1 gene copy reduced BACE1 amyloidolytic activity by ~ 50%. In cells, a stepwise increase of BACE1 but not APP expression promoted amyloidolytic cleavage resulting in dose-dependently increased Aβ34 levels. At the cellular level, a mislocalization of surplus BACE1 caused a reduction in Aβ34 levels. To align the role of γ-secretase in this pathway, we silenced Presenilin (PS) expression and identified PS2-γ-secretase as the main γ-secretase that generates Aβ40 and Aβ42 peptides serving as substrates for BACE1's amyloidolytic cleavage to generate Aβ34.
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Affiliation(s)
- Irem Ulku
- Integrated Program in Neuroscience, McGill University, Montreal, QC, H3G 0B1, Canada
| | - Filip Liebsch
- Integrated Program in Neuroscience, McGill University, Montreal, QC, H3G 0B1, Canada.,Department of Chemistry, Institute of Biochemistry, University of Cologne, 50674, Cologne, Germany
| | - S Can Akerman
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Jana F Schulz
- Institut Für Chemie Und Biochemie, Freie Universität Berlin, 14195, Berlin, Germany.,Cardiovascular and Metabolic Sciences, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125, Berlin, Germany
| | - Luka Kulic
- Roche Pharma Research & Early Development, F.Hoffmann-La Roche Ltd., 4070, Basel, Switzerland
| | - Christoph Hock
- Institute for Regenerative Medicine, Un Iversity of Zurich, 8952, Schlieren, Switzerland.,Neurimmune AG, 8952, Schlieren, Switzerland
| | - Claus Pietrzik
- Department Molecular Neurodegeneration, Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg-University of Mainz, Duesbergweg 6, 55099, Mainz, Germany
| | | | - Gopal Thinakaran
- Department of Molecular Medicine and Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, 33613, USA
| | - Paul Saftig
- Biochemisches Institut, CAU Kiel, Olshausenstr. 40, 24098, Kiel, Germany
| | - Gerhard Multhaup
- Integrated Program in Neuroscience, McGill University, Montreal, QC, H3G 0B1, Canada. .,Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, H3G 1Y6, Canada.
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4
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Marengo L, Armbrust F, Schoenherr C, Storck SE, Schmitt U, Zampar S, Wirths O, Altmeppen H, Glatzel M, Kaether C, Weggen S, Becker-Pauly C, Pietrzik CU. Meprin β knockout reduces brain Aβ levels and rescues learning and memory impairments in the APP/lon mouse model for Alzheimer's disease. Cell Mol Life Sci 2022; 79:168. [PMID: 35235058 PMCID: PMC8891209 DOI: 10.1007/s00018-022-04205-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 01/26/2022] [Accepted: 02/10/2022] [Indexed: 11/25/2022]
Abstract
β-Site amyloid precursor protein (APP) cleaving enzyme-1 (BACE1) is the major described β-secretase to generate Aβ peptides in Alzheimer's disease (AD). However, all therapeutic attempts to block BACE1 activity and to improve AD symptoms have so far failed. A potential candidate for alternative Aβ peptides generation is the metalloproteinase meprin β, which cleaves APP predominantly at alanine in p2 and in this study we can detect an increased meprin β expression in AD brain. Here, we report the generation of the transgenic APP/lon mouse model of AD lacking the functional Mep1b gene (APP/lon × Mep1b-/-). We examined levels of canonical and truncated Aβ species using urea-SDS-PAGE, ELISA and immunohistochemistry in brains of APP/lon mouse × Mep1b-/-. Additionally, we investigated the cognitive abilities of these mice during the Morris water maze task. Aβ1-40 and 1-42 levels are reduced in APP/lon mice when meprin β is absent. Immunohistochemical staining of mouse brain sections revealed that N-terminally truncated Aβ2-x peptide deposition is decreased in APP/lon × Mep1b-/- mice. Importantly, loss of meprin β improved cognitive abilities and rescued learning behavior impairments in APP/lon mice. These observations indicate an important role of meprin β within the amyloidogenic pathway and Aβ production in vivo.
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Affiliation(s)
- Liana Marengo
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Fred Armbrust
- Institute of Biochemistry, Unit for Degradomics of the Protease Web, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Caroline Schoenherr
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Steffen E. Storck
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Ulrich Schmitt
- Leibniz-Institute for Resilience Research, Mainz, Germany
| | - Silvia Zampar
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen (UMG), Göttingen, Germany
| | - Oliver Wirths
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen (UMG), Göttingen, Germany
| | - Hermann Altmeppen
- Institute of Neuropathology, University Medical Center HH-Eppendorf, Hamburg, Germany
| | - Markus Glatzel
- Institute of Neuropathology, University Medical Center HH-Eppendorf, Hamburg, Germany
| | | | - Sascha Weggen
- Department of Neuropathology, Heinrich Heine University, Düsseldorf, Germany
| | - Christoph Becker-Pauly
- Institute of Biochemistry, Unit for Degradomics of the Protease Web, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Claus U. Pietrzik
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- Molecular Neurodegeneration, Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Duesbergweg 6, 55099 Mainz, Germany
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5
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Thonda S, Puttapaka SN, Kona SV, Kalivendi SV. Extracellular-Signal-Regulated Kinase Inhibition Switches APP Processing from β- to α-Secretase under Oxidative Stress: Modulation of ADAM10 by SIRT1/NF-κB Signaling. ACS Chem Neurosci 2021; 12:4175-4186. [PMID: 34647720 DOI: 10.1021/acschemneuro.1c00582] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The sequential cleavage of full-length amyloid precursor protein (APP) by secretases has been at the center of efforts for understanding the onset of Alzheimer's disease (AD). A decrease in α-secretase activity was observed during the progression of AD; however, the precise molecular mechanism involved in the downregulation of α-secretase under oxidative stress is not fully understood. In the present study, we have demonstrated that pharmacological inhibition of mitogen-activated protein kinase/extracellular-signal-regulated kinase (MAPK/ERK) by mitogen-activated protein kinase kinase-1 (MEK-1) inhibitor (PD98059) restored the expression of a disintegrin and metalloproteinase 10 (ADAM10) with a concomitant decrease in β-site APP cleavage enzyme 1 (BACE1) under oxidative stress. Silent mating-type information regulation 2 homologue 1 (SIRT1) activation by resveratrol also mitigated alterations in secretase levels through MAPK/ERK signaling. Intracerebroventricular (ICV) administration of streptozotocin in rats showed amyloidogenic processing of APP and altered the SIRT1/ERK axis in the hippocampus. We also observed that the ADAM10 expression is controlled at the transcriptional level by oxidative stress. Using the luciferase reporter activity of ADAM10 promoter deletion constructs, we have identified the region 290 bp upstream of the transcription start site (TSS) possessing regulatory elements responsible for ADAM10 downregulation with hydrogen peroxide (H2O2) treatment. Further, bioinformatics analysis revealed the presence of putative nuclear factor kappa B (NF-κB) binding sites in the ADAM10 promoter region. Treatment of cortical neurons with the NF-κB inhibitor (Bay 11-7082) mitigated the transcriptional upregulation of ADAM10 by PD98059. Overall, our findings suggest that SIRT1/ERK/NF-κB axis contributes to the downregulation of ADAM10, resulting in the shift from nonamyloidogenic to amyloidogenic processing of APP under oxidative stress.
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Affiliation(s)
- Swaroop Thonda
- Department of Applied Biology, CSIR─Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad 500007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Srinivas N. Puttapaka
- Department of Applied Biology, CSIR─Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad 500007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Swathi V. Kona
- Department of Applied Biology, CSIR─Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad 500007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Shasi V. Kalivendi
- Department of Applied Biology, CSIR─Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad 500007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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6
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Armbrust F, Bickenbach K, Marengo L, Pietrzik C, Becker-Pauly C. The Swedish dilemma - the almost exclusive use of APPswe-based mouse models impedes adequate evaluation of alternative β-secretases. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1869:119164. [PMID: 34699873 DOI: 10.1016/j.bbamcr.2021.119164] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/30/2021] [Accepted: 10/11/2021] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is the most common form of dementia, however incurable so far. It is widely accepted that aggregated amyloid β (Aβ) peptides play a crucial role for the pathogenesis of AD, as they cause neurotoxicity and deposit as so-called Aβ plaques in AD patient brains. Aβ peptides derive from the amyloid precursor protein (APP) upon consecutive cleavage at the β- and γ-secretase site. Hence, mutations in the APP gene are often associated with autosomal dominant inherited AD. Almost thirty years ago, two mutations at the β-secretase site were observed in two Swedish families (termed Swedish APP (APPswe) mutations), which led to early-onset AD. Consequently, APPswe was established in almost every common AD mouse model, as it contributes to early Aβ plaque formation and cognitive impairments. Analyzing these APPswe-based mouse models, the aspartyl protease BACE1 has been evolving as the prominent β-secretase responsible for Aβ release in AD and as the most important therapeutic target for AD treatment. However, with respect to β-secretase processing, the very rare occurring APPswe variant substantially differs from wild-type APP. BACE1 dominates APPswe processing resulting in the release of Aβ1-x, whereas N-terminally truncated Aβ forms are scarcely generated. However, these N-terminally truncated Aβ species such as Aβ2-x, Aβ3-x and Aβ4-x are elevated in AD patient brains and exhibit an increased potential to aggregate compared to Aβ1-x peptides. Proteases such as meprin β, cathepsin B and ADAMTS4 were identified as alternative β-secretases being capable of generating these N-terminally truncated Aβ species from wild-type APP. However, neither meprin β nor cathepsin B are capable of generating N-terminally truncated Aβ peptides from APPswe. Hence, the role of BACE1 for the Aβ formation during AD might be overrepresented through the excessive use of APPswe mouse models. In this review we critically discuss the consideration of BACE1 as the most promising therapeutic target. Shifting the focus of AD research towards alternative β secretases might unveil promising alternatives to BACE1 inhibitors constantly failing in clinical trials due to ineffectiveness and harmful side effects.
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Affiliation(s)
- Fred Armbrust
- Biochemical Institute, Unit for Degradomics of the Protease Web, University of Kiel, Kiel, Germany
| | - Kira Bickenbach
- Biochemical Institute, Unit for Degradomics of the Protease Web, University of Kiel, Kiel, Germany
| | - Liana Marengo
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Claus Pietrzik
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.
| | - Christoph Becker-Pauly
- Biochemical Institute, Unit for Degradomics of the Protease Web, University of Kiel, Kiel, Germany.
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7
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Rinoldi C, Zargarian SS, Nakielski P, Li X, Liguori A, Petronella F, Presutti D, Wang Q, Costantini M, De Sio L, Gualandi C, Ding B, Pierini F. Nanotechnology-Assisted RNA Delivery: From Nucleic Acid Therapeutics to COVID-19 Vaccines. SMALL METHODS 2021; 5:e2100402. [PMID: 34514087 PMCID: PMC8420172 DOI: 10.1002/smtd.202100402] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/04/2021] [Indexed: 05/07/2023]
Abstract
In recent years, the main quest of science has been the pioneering of the groundbreaking biomedical strategies needed for achieving a personalized medicine. Ribonucleic acids (RNAs) are outstanding bioactive macromolecules identified as pivotal actors in regulating a wide range of biochemical pathways. The ability to intimately control the cell fate and tissue activities makes RNA-based drugs the most fascinating family of bioactive agents. However, achieving a widespread application of RNA therapeutics in humans is still a challenging feat, due to both the instability of naked RNA and the presence of biological barriers aimed at hindering the entrance of RNA into cells. Recently, material scientists' enormous efforts have led to the development of various classes of nanostructured carriers customized to overcome these limitations. This work systematically reviews the current advances in developing the next generation of drugs based on nanotechnology-assisted RNA delivery. The features of the most used RNA molecules are presented, together with the development strategies and properties of nanostructured vehicles. Also provided is an in-depth overview of various therapeutic applications of the presented systems, including coronavirus disease vaccines and the newest trends in the field. Lastly, emerging challenges and future perspectives for nanotechnology-mediated RNA therapies are discussed.
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Affiliation(s)
- Chiara Rinoldi
- Department of Biosystems and Soft MatterInstitute of Fundamental Technological ResearchPolish Academy of Sciencesul. Pawińskiego 5BWarsaw02‐106Poland
| | - Seyed Shahrooz Zargarian
- Department of Biosystems and Soft MatterInstitute of Fundamental Technological ResearchPolish Academy of Sciencesul. Pawińskiego 5BWarsaw02‐106Poland
| | - Pawel Nakielski
- Department of Biosystems and Soft MatterInstitute of Fundamental Technological ResearchPolish Academy of Sciencesul. Pawińskiego 5BWarsaw02‐106Poland
| | - Xiaoran Li
- Innovation Center for Textile Science and TechnologyDonghua UniversityWest Yan'an Road 1882Shanghai200051China
| | - Anna Liguori
- Department of Chemistry “Giacomo Ciamician” and INSTM UdR of BolognaUniversity of BolognaVia Selmi 2Bologna40126Italy
| | - Francesca Petronella
- Institute of Crystallography CNR‐ICNational Research Council of ItalyVia Salaria Km 29.300Monterotondo – Rome00015Italy
| | - Dario Presutti
- Institute of Physical ChemistryPolish Academy of Sciencesul. M. Kasprzaka 44/52Warsaw01‐224Poland
| | - Qiusheng Wang
- Innovation Center for Textile Science and TechnologyDonghua UniversityWest Yan'an Road 1882Shanghai200051China
| | - Marco Costantini
- Institute of Physical ChemistryPolish Academy of Sciencesul. M. Kasprzaka 44/52Warsaw01‐224Poland
| | - Luciano De Sio
- Department of Medico‐Surgical Sciences and BiotechnologiesResearch Center for BiophotonicsSapienza University of RomeCorso della Repubblica 79Latina04100Italy
- CNR‐Lab. LicrylInstitute NANOTECArcavacata di Rende87036Italy
| | - Chiara Gualandi
- Department of Chemistry “Giacomo Ciamician” and INSTM UdR of BolognaUniversity of BolognaVia Selmi 2Bologna40126Italy
- Interdepartmental Center for Industrial Research on Advanced Applications in Mechanical Engineering and Materials TechnologyCIRI‐MAMUniversity of BolognaViale Risorgimento 2Bologna40136Italy
| | - Bin Ding
- Innovation Center for Textile Science and TechnologyDonghua UniversityWest Yan'an Road 1882Shanghai200051China
| | - Filippo Pierini
- Department of Biosystems and Soft MatterInstitute of Fundamental Technological ResearchPolish Academy of Sciencesul. Pawińskiego 5BWarsaw02‐106Poland
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8
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Dekeryte R, Franklin Z, Hull C, Croce L, Kamli-Salino S, Helk O, Hoffmann PA, Yang Z, Riedel G, Delibegovic M, Platt B. The BACE1 inhibitor LY2886721 improves diabetic phenotypes of BACE1 knock-in mice. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166149. [PMID: 33892080 DOI: 10.1016/j.bbadis.2021.166149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 03/18/2021] [Accepted: 04/13/2021] [Indexed: 11/24/2022]
Abstract
AIM The β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) has been identified as the central initiator of amyloid β (Aβ) generation in the brain, the key hallmark of Alzheimer's disease (AD). However, recent studies provided evidence that BACE1 also plays a crucial role in metabolic regulation, and we have shown that neuronal human BACE1 knock-in mice (PLB4) display type 2 diabetes mellitus (T2DM)-like symptoms alongside AD-like impairments. Hence, we here investigated if targeted BACE1 inhibition using LY2886721, an active site BACE1 inhibitor, would improve glucose homeostasis, insulin sensitivity and motor performance in PLB4 mice. MATERIALS AND METHODS LY2886721 was administered as a dietary supplement (0.02% wt/wt) for six consecutive weeks. Physiological, metabolic and motor assessments were performed during the last two weeks of treatment, followed by molecular tissue analyses post-mortem. RESULTS LY2886721 treatment improved glucose homeostasis and hepatic gluconeogenesis in diabetic PLB4 mice, as determined by improvements in basal glucose and glucose/pyruvate tolerance tests. Furthermore, LY2886721 improved hepatic insulin sensitivity, as indicated by enhanced basal hyperphosphorylation of insulin receptors. In PLB4 brains, we detected altered basal conditions of APP expression and processing, with beneficial effects on APP processing achieved by LY2886721 treatment. No improvements in motor coordination were found. CONCLUSIONS Our data provide support for a role of BACE1 as a regulator of systemic glucose homeostasis and suggest BACE1 inhibitors for the treatment of T2DM-associated pathologies, especially in cases where diabetes is comorbid to AD.
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Affiliation(s)
- Ruta Dekeryte
- Institute of Medical Sciences, University of Aberdeen, Foresterhill Health Campus, Aberdeen AB25 2ZD, UK
| | - Zara Franklin
- Institute of Medical Sciences, University of Aberdeen, Foresterhill Health Campus, Aberdeen AB25 2ZD, UK
| | - Claire Hull
- Institute of Medical Sciences, University of Aberdeen, Foresterhill Health Campus, Aberdeen AB25 2ZD, UK
| | - Lorenzo Croce
- Institute of Medical Sciences, University of Aberdeen, Foresterhill Health Campus, Aberdeen AB25 2ZD, UK
| | - Sarah Kamli-Salino
- Institute of Medical Sciences, University of Aberdeen, Foresterhill Health Campus, Aberdeen AB25 2ZD, UK
| | - Oliver Helk
- Institute of Medical Sciences, University of Aberdeen, Foresterhill Health Campus, Aberdeen AB25 2ZD, UK
| | - Philip A Hoffmann
- Institute of Medical Sciences, University of Aberdeen, Foresterhill Health Campus, Aberdeen AB25 2ZD, UK
| | - Zhixiang Yang
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Gernot Riedel
- Institute of Medical Sciences, University of Aberdeen, Foresterhill Health Campus, Aberdeen AB25 2ZD, UK
| | - Mirela Delibegovic
- Institute of Medical Sciences, University of Aberdeen, Foresterhill Health Campus, Aberdeen AB25 2ZD, UK.
| | - Bettina Platt
- Institute of Medical Sciences, University of Aberdeen, Foresterhill Health Campus, Aberdeen AB25 2ZD, UK.
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9
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Jin X, Yang L, Yan X, Wang Q. Screening Platform Based on Inductively Coupled Plasma Mass Spectrometry for β-Site Amyloid Protein Cleaving Enzyme 1 (BACE1) Inhibitors. ACS Chem Neurosci 2021; 12:1093-1099. [PMID: 33764738 DOI: 10.1021/acschemneuro.0c00816] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
β-Site amyloid protein cleaving enzyme 1 (BACE1) is a promising therapeutic target for developing inhibitors to alleviate Alzheimer's disease (AD). Herein, we established an inductively coupled plasma mass spectrometry (ICPMS)-based inhibitor screening platform. A biotin-labeled lanthanide-coded peptide probe (LCPP; biotin-PEG2-EVNLDAEC-DOTA-Ln) was designed to determine the activity of BACE1 and evaluate the degree of inhibition of inhibitors. The platform was first validated with two commercially available inhibitors (BSI I and BSI IV) in terms of IC50 values and then applied to two newly designed inhibitors (inhibitors II and III) based on the crystal structure of BACE1 interacting with inhibitor I, and each of them contained an acylguanidine core structure. We found that their inhibition effects were improved as evaluated by the sensitive and accurate LCPP-ICPMS platform, demonstrating its ability for new drug screening.
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Affiliation(s)
- Xin Jin
- Department of Chemistry and the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Limin Yang
- Department of Chemistry and the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Xiaowen Yan
- Department of Chemistry and the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Qiuquan Wang
- Department of Chemistry and the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
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10
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Kakinen A, Javed I, Davis TP, Ke PC. In vitro and in vivo models for anti-amyloidosis nanomedicines. NANOSCALE HORIZONS 2021; 6:95-119. [PMID: 33438715 DOI: 10.1039/d0nh00548g] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Amyloid diseases are global epidemics characterized by the accumulative deposits of cross-beta amyloid fibrils and plaques. Despite decades of intensive research, few solutions are available for the diagnosis, treatment, and prevention of these debilitating diseases. Since the early work on the interaction of human β2-microglobulin and nanoparticles by Linse et al. in 2007, the field of amyloidosis inhibition has gradually evolved into a new frontier in nanomedicine offering numerous interdisciplinary research opportunities, especially for materials, chemistry and biophysics. In this review we summarise, for the first time, the in vitro and in vivo models employed thus far in the field of anti-amyloidosis nanomedicines. Based on this systematic summary, we bring forth the notion that, due to the complex and often overlapping physiopathologies of amyloid diseases, there is a crucial need for the appropriate use of in vitro and in vivo models for validating novel anti-amyloidosis nanomedicines, and there is a crucial need for the development of new animal models that reflect the behavioural, symptomatic and cross-talk hallmarks of amyloid diseases such as Alzheimer's (AD), Parkinson's (PD) diseases and type 2 diabetes (T2DM).
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Affiliation(s)
- Aleksandr Kakinen
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia.
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11
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Pinheiro L, Faustino C. Therapeutic Strategies Targeting Amyloid-β in Alzheimer's Disease. Curr Alzheimer Res 2020; 16:418-452. [PMID: 30907320 DOI: 10.2174/1567205016666190321163438] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 03/16/2019] [Accepted: 03/17/2019] [Indexed: 12/16/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder linked to protein misfolding and aggregation. AD is pathologically characterized by senile plaques formed by extracellular Amyloid-β (Aβ) peptide and Intracellular Neurofibrillary Tangles (NFT) formed by hyperphosphorylated tau protein. Extensive synaptic loss and neuronal degeneration are responsible for memory impairment, cognitive decline and behavioral dysfunctions typical of AD. Amyloidosis has been implicated in the depression of acetylcholine synthesis and release, overactivation of N-methyl-D-aspartate (NMDA) receptors and increased intracellular calcium levels that result in excitotoxic neuronal degeneration. Current drugs used in AD treatment are either cholinesterase inhibitors or NMDA receptor antagonists; however, they provide only symptomatic relief and do not alter the progression of the disease. Aβ is the product of Amyloid Precursor Protein (APP) processing after successive cleavage by β- and γ-secretases while APP proteolysis by α-secretase results in non-amyloidogenic products. According to the amyloid cascade hypothesis, Aβ dyshomeostasis results in the accumulation and aggregation of Aβ into soluble oligomers and insoluble fibrils. The former are synaptotoxic and can induce tau hyperphosphorylation while the latter deposit in senile plaques and elicit proinflammatory responses, contributing to oxidative stress, neuronal degeneration and neuroinflammation. Aβ-protein-targeted therapeutic strategies are thus a promising disease-modifying approach for the treatment and prevention of AD. This review summarizes recent findings on Aβ-protein targeted AD drugs, including β-secretase inhibitors, γ-secretase inhibitors and modulators, α-secretase activators, direct inhibitors of Aβ aggregation and immunotherapy targeting Aβ, focusing mainly on those currently under clinical trials.
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Affiliation(s)
- Lídia Pinheiro
- iMed.ULisboa - Research Institute for Medicines, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto 1649-003 Lisboa, Portugal
| | - Célia Faustino
- iMed.ULisboa - Research Institute for Medicines, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto 1649-003 Lisboa, Portugal
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12
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Finnie PSB, Nader K. Amyloid Beta Secreted during Consolidation Prevents Memory Malleability. Curr Biol 2020; 30:1934-1940.e4. [PMID: 32243855 DOI: 10.1016/j.cub.2020.02.083] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 01/21/2020] [Accepted: 02/26/2020] [Indexed: 12/21/2022]
Abstract
Memory allows organisms to predict future events based on their prior sampling of the world. Rather than faithfully encoding each detail of related episodes, the brain is thought to incrementally construct probabilistic estimates of environmental statistics that are re-evaluated each time relevant events are encountered [1]. When faced with evidence that does not adequately fit mnemonic predictions, a process called reconsolidation can alter relevant memories to better recapitulate ongoing experience [2]. Conversely, when an ongoing event matches well-established predictions, reactivated memories tend to remain stable [3, 4]. In part, the brain may confer selective mnemonic stability by shifting cell-intrinsic mechanisms of plasticity induction [5], which could serve to constrain maladaptive updating of reliably predictive representations during anomalous events. Based on evidence of decreased cognitive flexibility and restricted synaptic plasticity in later life [6], we hypothesized that some prevalent age-associated neurobiological changes might in fact contribute to mnemonic stability [7]. Specifically, we predicted that amyloid beta (Aβ)-a peptide that often accumulates in the brains of individuals expressing senescent dementia [8-10]-is required for memory stabilization. Indeed, we observe elevated soluble Aβx-42 concentrations in the amygdala shortly after young adult rats form reconsolidation-resistant auditory fear memories. Suppressing secretases required for Aβ production immediately after learning prevents mnemonic stabilization, rendering these memories vulnerable to disruption by post-reactivation amnestic treatments. Thus, the seemingly pathogenic Aβ42 peptide may serve an adaptive physiological function during memory consolidation by engaging mechanisms that protect reliably predictive representations against subsequent modification.
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Affiliation(s)
- Peter S B Finnie
- Psychology Department, McGill University, 1205 Avenue Dr. Penfield, Montreal, QC H3A 1B1, Canada.
| | - Karim Nader
- Psychology Department, McGill University, 1205 Avenue Dr. Penfield, Montreal, QC H3A 1B1, Canada.
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13
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Austin SA, Katusic ZS. Partial loss of endothelial nitric oxide leads to increased cerebrovascular beta amyloid. J Cereb Blood Flow Metab 2020; 40:392-403. [PMID: 30614363 PMCID: PMC7370614 DOI: 10.1177/0271678x18822474] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cerebral amyloid angiopathy (CAA) is present in over half of the elderly population and in 80-90% of Alzheimer's disease (AD) patients. CAA is defined by the deposition of beta amyloid (Aβ) in small cerebral arteries and capillaries. Cardiovascular risk factors are associated with an increased incidence of CAA. We utilized 18-month-old endothelial nitric oxide synthase (eNOS) heterozygous knockout (+/-) mice, a clinically relevant model of endothelial dysfunction, to examine the role of endothelial nitric oxide (NO) in vascular Aβ accumulation. eNOS+/- mice had significantly higher vascular levels of Aβ40 (P < 0.05). Aβ42 was not detected. There was no difference in Aβ in brain tissue. Amyloid precursor protein and β-site APP cleavage enzyme 1 protein levels were unaltered, while levels of the α-secretase enzyme, a disintegrin and metalloproteinase 10, were significantly lower in eNOS + /- microvascular tissue (P < 0.05). Insulin degrading enzyme and low-density lipoprotein receptor-related protein 1 were significantly increased in eNOS+/- microvascular tissue, most likely an adaptive response to locally higher Aβ concentrations. Lastly, catalase and CuZn superoxide dismutase were significantly elevated in eNOS+/- microvascular tissue (P < 0.05). These data demonstrate decreased availability of endothelial NO leads to increased cerebrovascular concentration of Aβ along with compensatory mechanisms to protect the vasculature.
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Affiliation(s)
- Susan A Austin
- Departments of Anesthesiology and Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Zvonimir S Katusic
- Departments of Anesthesiology and Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN, USA
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14
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Lombardo S, Chiacchiaretta M, Tarr A, Kim W, Cao T, Sigal G, Rosahl TW, Xia W, Haydon PG, Kennedy ME, Tesco G. BACE1 partial deletion induces synaptic plasticity deficit in adult mice. Sci Rep 2019; 9:19877. [PMID: 31882662 PMCID: PMC6934620 DOI: 10.1038/s41598-019-56329-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 12/10/2019] [Indexed: 12/13/2022] Open
Abstract
BACE1 is the first enzyme involved in APP processing, thus it is a strong therapeutic target candidate for Alzheimer's disease. The observation of deleterious phenotypes in BACE1 Knock-out (KO) mouse models (germline and conditional) raised some concerns on the safety and tolerability of BACE1 inhibition. Here, we have employed a tamoxifen inducible BACE1 conditional Knock-out (cKO) mouse model to achieve a controlled partial depletion of BACE1 in adult mice. Biochemical and behavioural characterization was performed at two time points: 4-5 months (young mice) and 12-13 months (aged mice). A ~50% to ~70% BACE1 protein reduction in hippocampus and cortex, respectively, induced a significant reduction of BACE1 substrates processing and decrease of Aβx-40 levels at both ages. Hippocampal axonal guidance and peripheral nerve myelination were not affected. Aged mice displayed a CA1 long-term potentiation (LTP) deficit that was not associated with memory impairment. Our findings indicate that numerous phenotypes observed in germline BACE1 KO reflect a fundamental role of BACE1 during development while other phenotypes, observed in adult cKO, may be absent when partially rather than completely deleting BACE1. However, we demonstrated that partial depletion of BACE1 still induces CA1 LTP impairment, supporting a role of BACE1 in synaptic plasticity in adulthood.
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Affiliation(s)
- Sylvia Lombardo
- Alzheimer's Disease Research Laboratory, Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, 02111, USA
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, 02111, USA
| | - Martina Chiacchiaretta
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, 02111, USA
| | - Andrew Tarr
- Circuits and Behaviour Core, Center for Neuroscience Research, Tufts University School of Medicine, Boston, Massachusetts, 02111, USA
| | - WonHee Kim
- Alzheimer's Disease Research Laboratory, Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, 02111, USA
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, 02111, USA
| | - Tingyi Cao
- Alzheimer's Disease Research Laboratory, Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, 02111, USA
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, 02111, USA
| | - Griffin Sigal
- Alzheimer's Disease Research Laboratory, Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, 02111, USA
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, 02111, USA
| | - Thomas W Rosahl
- External In Vivo Pharmacology, Merck & Co. Inc., Kenilworth, NJ, 07033, USA
| | - Weiming Xia
- Geriatric Research, Education and Clinic Center, Bedford Veterans Affairs Medical Center, Bedford, MA, 01730, USA
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, 02118, USA
| | - Philip G Haydon
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, 02111, USA
| | | | - Giuseppina Tesco
- Alzheimer's Disease Research Laboratory, Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, 02111, USA.
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, 02111, USA.
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15
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Molecular insights into the inhibitory mechanism of bi-functional bis-tryptoline triazole against β-secretase (BACE1) enzyme. Amino Acids 2019; 51:1593-1607. [PMID: 31654211 DOI: 10.1007/s00726-019-02797-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 10/04/2019] [Indexed: 02/07/2023]
Abstract
The β-site amyloid precursor protein-cleaving enzyme 1 (β-secretase, BACE1) is involved in the formation of amyloid-β (Aβ) peptide that aggregates into soluble oligomers, amyloid fibrils, and plaques responsible for the neurodegeneration in Alzheimer disease (AD). BACE1 is one of the prime therapeutic targets for the design of inhibitors against AD as BACE1 participate in the rate-limiting step in Aβ production. Jiaranaikulwanitch et al. reported bis-tryptoline triazole (BTT) compound as a potent inhibitor against BACE1, Aβ aggregation as well as possessing metal chelation and antioxidant activity. However, the molecular mechanism of BACE1 inhibition by BTT remains unclear. Thus, molecular docking and molecular dynamics (MD) simulations were performed to elucidate the inhibitory mechanism of BTT against BACE1. MD simulations highlight that BTT interact with catalytic aspartic dyad residues (Asp32 and Asp228) and active pocket residues of BACE1. The hydrogen-bond interactions, hydrophobic contacts, and π-π stacking interactions of BTT with flap residues (Val67-Asp77) of BACE1 confine the movement of the flap and help to achieve closed (non-active) conformation. The PCA analysis highlights lower conformational fluctuations for BACE1-BTT complex, which suggests enhanced conformational stability in comparison to apo-BACE1. The results of the present study provide key insights into the underlying inhibitory mechanism of BTT against BACE1 and will be helpful for the rational design of novel inhibitors with enhanced potency against BACE1.
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16
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Sun R, He T, Pan Y, Katusic ZS. Effects of senescence and angiotensin II on expression and processing of amyloid precursor protein in human cerebral microvascular endothelial cells. Aging (Albany NY) 2019; 10:100-114. [PMID: 29348391 PMCID: PMC5811245 DOI: 10.18632/aging.101362] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 01/10/2018] [Indexed: 01/18/2023]
Abstract
The present study was designed to determine the effects of senescence and angiotensin II (Ang II) on expression and processing of amyloid precursor protein (APP) in human brain microvascular endothelial cells (BMECs). Senescence caused a decrease in APP expression thereby resulting in reduced secretion of soluble APPα (sAPPα). In contrast, β-site APP cleaving enzyme (BACE1) expression and production of amyloid β (Aβ)40 were increased in senescent endothelium. Importantly, in senescent human BMECs, treatment with BACE1 inhibitor IV inhibited Aβ generation and increased sAPPα production by enhancing a disintegrin and metalloprotease (ADAM)10 expression. Furthermore, Ang II impaired expression of ADAM10 and significantly reduced generation of sAPPα in senescent human BMECs. This inhibitory effect of Ang II was prevented by treatment with BACE1 inhibitor IV. Our results suggest that impairment of α-processing and shift to amyloidogenic pathway of APP contribute to endothelial dysfunction induced by senescence. Loss of sAPPα in senescent cells treated with Ang II exacerbates detrimental effects of senescence on APP processing. Notably, inhibition of BACE1 has beneficial effects on senescence induced endothelial dysfunction. Reported findings may help to explain contributions of senescent cerebral microvascular endothelium to development of cerebral amyloid angiopathy and Alzheimer’s disease (AD) pathology.
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Affiliation(s)
- Ruohan Sun
- Department of Neurology, the First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, 150001, China.,Department of Anesthesiology and Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Tongrong He
- Department of Anesthesiology and Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Yujun Pan
- Department of Neurology, the First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, 150001, China
| | - Zvonimir S Katusic
- Department of Anesthesiology and Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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17
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Scharfenberg F, Armbrust F, Marengo L, Pietrzik C, Becker-Pauly C. Regulation of the alternative β-secretase meprin β by ADAM-mediated shedding. Cell Mol Life Sci 2019; 76:3193-3206. [PMID: 31201463 PMCID: PMC11105663 DOI: 10.1007/s00018-019-03179-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 05/23/2019] [Accepted: 05/29/2019] [Indexed: 12/12/2022]
Abstract
Alzheimer's Disease (AD) is the sixth-leading cause of death in industrialized countries. Neurotoxic amyloid-β (Aβ) plaques are one of the pathological hallmarks in AD patient brains. Aβ accumulates in the brain upon sequential, proteolytic processing of the amyloid precursor protein (APP) by β- and γ-secretases. However, so far disease-modifying drugs targeting β- and γ-secretase pathways seeking a decrease in the production of toxic Aβ peptides have failed in clinics. It has been demonstrated that the metalloproteinase meprin β acts as an alternative β-secretase, capable of generating truncated Aβ2-x peptides that have been described to be increased in AD patients. This indicates an important β-site cleaving enzyme 1 (BACE-1)-independent contribution of the metalloprotease meprin β within the amyloidogenic pathway and may lead to novel drug targeting avenues. However, meprin β itself is embedded in a complex regulatory network. Remarkably, the anti-amyloidogenic α-secretase a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) is a direct competitor for APP at the cell surface, but also a sheddase of inactive pro-meprin β. Overall, we highlight the current cellular, molecular and structural understanding of meprin β as alternative β-secretase within the complex protease web, regulating APP processing in health and disease.
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Affiliation(s)
- Franka Scharfenberg
- Unit for Degradomics of the Protease Web, Biochemical Institute, University of Kiel, Kiel, Germany
| | - Fred Armbrust
- Unit for Degradomics of the Protease Web, Biochemical Institute, University of Kiel, Kiel, Germany
| | - Liana Marengo
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Claus Pietrzik
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.
| | - Christoph Becker-Pauly
- Unit for Degradomics of the Protease Web, Biochemical Institute, University of Kiel, Kiel, Germany.
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18
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Liebsch F, Kulic L, Teunissen C, Shobo A, Ulku I, Engelschalt V, Hancock MA, van der Flier WM, Kunach P, Rosa-Neto P, Scheltens P, Poirier J, Saftig P, Bateman RJ, Breitner J, Hock C, Multhaup G. Aβ34 is a BACE1-derived degradation intermediate associated with amyloid clearance and Alzheimer's disease progression. Nat Commun 2019; 10:2240. [PMID: 31110178 PMCID: PMC6527709 DOI: 10.1038/s41467-019-10152-w] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 04/17/2019] [Indexed: 12/13/2022] Open
Abstract
The beta-site APP cleaving enzyme 1 (BACE1) is known primarily for its initial cleavage of the amyloid precursor protein (APP), which ultimately leads to the generation of Aβ peptides. Here, we provide evidence that altered BACE1 levels and activity impact the degradation of Aβ40 and Aβ42 into a common Aβ34 intermediate. Using human cerebrospinal fluid (CSF) samples from the Amsterdam Dementia Cohort, we show that Aβ34 is elevated in individuals with mild cognitive impairment who later progressed to dementia. Furthermore, Aβ34 levels correlate with the overall Aβ clearance rates in amyloid positive individuals. Using CSF samples from the PREVENT-AD cohort (cognitively normal individuals at risk for Alzheimer’s disease), we further demonstrate that the Aβ34/Aβ42 ratio, representing Aβ degradation and cortical deposition, associates with pre-clinical markers of neurodegeneration. We propose that Aβ34 represents a marker of amyloid clearance and may be helpful for the characterization of Aβ turnover in clinical samples. Aβ34 is generated from degradation of Aβ40 and Aβ42 by β-secretase. Here, the authors show that Aβ34 is a marker for amyloid clearance and is elevated in the CSF of patients that go on to convert from mild cognitive impairment to Alzheimer’s disease, suggesting it may be a useful biomarker.
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Affiliation(s)
- Filip Liebsch
- Department of Pharmacology and Therapeutics and Integrated Program in Neuroscience, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Luka Kulic
- Institute for Regenerative Medicine, University of Zurich, CH-8952, Schlieren, Switzerland
| | - Charlotte Teunissen
- Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081HZ, Amsterdam, The Netherlands
| | - Adeola Shobo
- Department of Pharmacology and Therapeutics and Integrated Program in Neuroscience, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Irem Ulku
- Department of Pharmacology and Therapeutics and Integrated Program in Neuroscience, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Vivienne Engelschalt
- Institut für Chemie und Biochemie, Freie Universität Berlin, 14195, Berlin, Germany
| | - Mark A Hancock
- SPR-MS Facility, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Wiesje M van der Flier
- Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, 1081HZ, The Netherlands
| | - Peter Kunach
- Translational Neuroimaging Laboratory, The McGill University Research Centre for Studies in Aging, Alzheimer's Disease Research Unit, Douglas Research Institute, McGill University, Montreal, H4H 1R3, QC, Canada
| | - Pedro Rosa-Neto
- Translational Neuroimaging Laboratory, The McGill University Research Centre for Studies in Aging, Alzheimer's Disease Research Unit, Douglas Research Institute, McGill University, Montreal, H4H 1R3, QC, Canada
| | - Philip Scheltens
- Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, 1081HZ, The Netherlands
| | - Judes Poirier
- Department of Psychiatry, McGill University, Montreal, QC, H4H 1R3, Canada
| | - Paul Saftig
- Biochemisches Institut, Christian-Albrechts-Universität-Kiel, 24118, Kiel, Germany
| | - Randall J Bateman
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - John Breitner
- Department of Psychiatry, McGill University, Montreal, QC, H4H 1R3, Canada
| | - Christoph Hock
- Institute for Regenerative Medicine, University of Zurich, CH-8952, Schlieren, Switzerland.,Neurimmune, CH-8952, Schlieren, Switzerland
| | - Gerhard Multhaup
- Department of Pharmacology and Therapeutics and Integrated Program in Neuroscience, McGill University, Montreal, QC, H3G 1Y6, Canada.
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19
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Xie X, Wu H, Li M, Chen X, Xu X, Ni W, Lu C, Ni R, Bao B, Xiao M. Progress in the application of exosomes as therapeutic vectors in tumor-targeted therapy. Cytotherapy 2019; 21:509-524. [DOI: 10.1016/j.jcyt.2019.01.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/05/2019] [Accepted: 01/08/2019] [Indexed: 12/13/2022]
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20
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Delivery of BACE1 siRNA mediated by TARBP-BTP fusion protein reduces β-amyloid deposits in a transgenic mouse model of Alzheimer’s disease. J Biosci 2019. [DOI: 10.1007/s12038-018-9822-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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Antes TJ, Middleton RC, Luther KM, Ijichi T, Peck KA, Liu WJ, Valle J, Echavez AK, Marbán E. Targeting extracellular vesicles to injured tissue using membrane cloaking and surface display. J Nanobiotechnology 2018; 16:61. [PMID: 30165851 PMCID: PMC6116387 DOI: 10.1186/s12951-018-0388-4] [Citation(s) in RCA: 154] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 08/16/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Extracellular vesicles (EVs) and exosomes are nano-sized, membrane-bound vesicles shed by most eukaryotic cells studied to date. EVs play key signaling roles in cellular development, cancer metastasis, immune modulation and tissue regeneration. Attempts to modify exosomes to increase their targeting efficiency to specific tissue types are still in their infancy. Here we describe an EV membrane anchoring platform termed "cloaking" to directly embed tissue-specific antibodies or homing peptides on EV membrane surfaces ex vivo for enhanced vesicle uptake in cells of interest. The cloaking system consists of three components: DMPE phospholipid membrane anchor, polyethylene glycol spacer and a conjugated streptavidin platform molecule, to which any biotinylated molecule can be coupled for EV decoration. RESULTS We demonstrate the utility of membrane surface engineering and biodistribution tracking with this technology along with targeting EVs for enhanced uptake in cardiac fibroblasts, myoblasts and ischemic myocardium using combinations of fluorescent tags, tissue-targeting antibodies and homing peptide surface cloaks. We compare cloaking to a complementary approach, surface display, in which parental cells are engineered to secrete EVs with fusion surface targeting proteins. CONCLUSIONS EV targeting can be enhanced both by cloaking and by surface display; the former entails chemical modification of preformed EVs, while the latter requires genetic modification of the parent cells. Reduction to practice of the cloaking approach, using several different EV surface modifications to target distinct cells and tissues, supports the notion of cloaking as a platform technology.
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Affiliation(s)
- Travis J. Antes
- Smidt Heart Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Davis Building, Los Angeles, CA 90048 USA
| | - Ryan C. Middleton
- Smidt Heart Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Davis Building, Los Angeles, CA 90048 USA
| | - Kristin M. Luther
- Smidt Heart Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Davis Building, Los Angeles, CA 90048 USA
| | - Takeshi Ijichi
- Smidt Heart Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Davis Building, Los Angeles, CA 90048 USA
| | - Kiel A. Peck
- Smidt Heart Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Davis Building, Los Angeles, CA 90048 USA
| | - Weixin Jane Liu
- Smidt Heart Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Davis Building, Los Angeles, CA 90048 USA
| | - Jackie Valle
- Smidt Heart Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Davis Building, Los Angeles, CA 90048 USA
| | - Antonio K. Echavez
- Smidt Heart Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Davis Building, Los Angeles, CA 90048 USA
| | - Eduardo Marbán
- Smidt Heart Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Davis Building, Los Angeles, CA 90048 USA
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BACE1 Regulates Proliferation and Neuronal Differentiation of Newborn Cells in the Adult Hippocampus in Mice. eNeuro 2018; 5:eN-NWR-0067-18. [PMID: 30079376 PMCID: PMC6073981 DOI: 10.1523/eneuro.0067-18.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 06/05/2018] [Accepted: 06/25/2018] [Indexed: 01/05/2023] Open
Abstract
β-Site amyloid precursor protein cleaving enzyme 1 (BACE1) is required for the production of β-amyloid (Aβ), one of the major pathogenic molecules of Alzheimer's disease (AD), and is therefore being actively pursued as a drug target for AD. Adult hippocampal neurogenesis (AHN) is a lifelong process that is known to be important for learning and memory and may have the potential to regenerate damaged neural tissue. In this study, we examined whether BACE1 regulates AHN, which holds important implications for its suitability as a drug target in AD. Cohorts of 2-month-old wild-type (BACE1+/+), heterozygous, and homozygous BACE1 knockout mice (BACE1+/- and BACE1-/-, respectively) were injected with 5-bromo-2'-deoxyuridine (BrdU) and sacrificed 1 day later to examine the impact of loss of BACE1 on neural precursor cell (NPC) proliferation in the adult brain. Parallel cohorts of mice were sacrificed 4 weeks after BrdU injection to determine the effects of BACE1 on survival and differentiation of newborn NPCs. We found that NPC proliferation was increased in BACE1-/- mice compared to BACE1+/+ mice, while no difference was observed in NPC survival across genotypes. Differentiation of NPCs to neuronal lineage was impaired in BACE1-/- mice. However, no differences were observed in astrogenesis, the proportion of immature neurons, or the production of oligodendrocytes across genotypes. Importantly, corresponding with a decrease in neuronal differentiation in the absence of a complementary increase in an alternate cell fate, BACE1-/- mice were found to have a pool of undifferentiated NPCs in the hippocampus compared to BACE1+/+ and BACE1+/- mice.
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Saima, Kumar L, Lavekar AG, Sharma T, Shamsuzzama, Equbal D, Siddiqi MI, Sinha AK, Nazir A. Chemo‐Biocatalytic Oxidative Condensation of Natural Arylpropene with 2‐Aminobenzothiazole into Schiff‐Bases as Potent Anti‐Amyloid Agents: Studies Employing Transgenic
C. elegans. ChemistrySelect 2018. [DOI: 10.1002/slct.201800243] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Saima
- Medicinal and Process Chemistry DivisionCSIR-Central Drug Research Institute Jankipuram extension Sitapur Road Lucknow, U.P. India
- Academy of Scientific and Innovative Research New Delhi India
| | - Lalit Kumar
- Toxicology divisionCSIR-Central Drug Research Institute Lucknow, U.P. India
| | - Aditya G. Lavekar
- Medicinal and Process Chemistry DivisionCSIR-Central Drug Research Institute Jankipuram extension Sitapur Road Lucknow, U.P. India
| | - Tanuj Sharma
- Molecular and Structural Biology DivisionCSIR-Central Drug Research Institute Lucknow, U.P. India
| | - Shamsuzzama
- Toxicology divisionCSIR-Central Drug Research Institute Lucknow, U.P. India
| | - Danish Equbal
- Medicinal and Process Chemistry DivisionCSIR-Central Drug Research Institute Jankipuram extension Sitapur Road Lucknow, U.P. India
| | - Mohammad Imran Siddiqi
- Molecular and Structural Biology DivisionCSIR-Central Drug Research Institute Lucknow, U.P. India
| | - Arun K. Sinha
- Medicinal and Process Chemistry DivisionCSIR-Central Drug Research Institute Jankipuram extension Sitapur Road Lucknow, U.P. India
- Academy of Scientific and Innovative Research New Delhi India
| | - Aamir Nazir
- Toxicology divisionCSIR-Central Drug Research Institute Lucknow, U.P. India
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24
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Nixon RA. Amyloid precursor protein and endosomal-lysosomal dysfunction in Alzheimer's disease: inseparable partners in a multifactorial disease. FASEB J 2017; 31:2729-2743. [PMID: 28663518 DOI: 10.1096/fj.201700359] [Citation(s) in RCA: 222] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 04/21/2017] [Indexed: 12/15/2022]
Abstract
Abnormalities of the endosomal-lysosomal network (ELN) are a signature feature of Alzheimer's disease (AD). These include the earliest known cytopathology that is specific to AD and that affects endosomes and induces the progressive failure of lysosomes, each of which are directly linked by distinct mechanisms to neurodegeneration. The origins of ELN dysfunction and β-amyloidogenesis closely overlap, which reflects their common genetic basis, the established early involvement of endosomes and lysosomes in amyloid precursor protein (APP) processing and clearance, and the pathologic effect of certain APP metabolites on ELN functions. Genes that promote β-amyloidogenesis in AD (APP, PSEN1/2, and APOE4) have primary effects on ELN function. The importance of primary ELN dysfunction to pathogenesis is underscored by the mutations in more than 35 ELN-related genes that, thus far, are known to cause familial neurodegenerative diseases even though different pathogenic proteins may be involved. In this article, I discuss growing evidence that implicates AD gene-driven ELN disruptions as not only the antecedent pathobiology that underlies β-amyloidogenesis but also as the essential partner with APP and its metabolites that drive the development of AD, including tauopathy, synaptic dysfunction, and neurodegeneration. The striking amelioration of diverse deficits in animal AD models by remediating ELN dysfunction further supports a need to integrate APP and ELN relationships, including the role of amyloid-β, into a broader conceptual framework of how AD arises, progresses, and may be effectively therapeutically targeted.-Nixon, R. A. Amyloid precursor protein and endosomal-lysosomal dysfunction in Alzheimer's disease: inseparable partners in a multifactorial disease.
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Affiliation(s)
- Ralph A Nixon
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, New York, USA; .,Department of Psychiatry and Department of Cell Biology, New York University Langone Medical Center, New York, New York, USA
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25
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BACE1 across species: a comparison of the in vivo consequences of BACE1 deletion in mice and rats. Sci Rep 2017; 7:44249. [PMID: 28281673 PMCID: PMC5345047 DOI: 10.1038/srep44249] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 02/06/2017] [Indexed: 01/18/2023] Open
Abstract
Assessing BACE1 (β-site APP cleaving enzyme 1) knockout mice for general health and neurological function may be useful in predicting risks associated with prolonged pharmacological BACE1 inhibition, a treatment approach currently being developed for Alzheimer’s disease. To determine whether BACE1 deletion-associated effects in mice generalize to another species, we developed a novel Bace1−/− rat line using zinc-finger nuclease technology and compared Bace1−/− mice and rats with their Bace1+/+ counterparts. Lack of BACE1 was confirmed in Bace1−/− animals from both species. Removal of BACE1 affected startle magnitude, balance beam performance, pain response, and nerve myelination in both species. While both mice and rats lacking BACE1 have shown increased mortality, the increase was smaller and restricted to early developmental stages for rats. Bace1−/− mice and rats further differed in body weight, spontaneous locomotor activity, and prepulse inhibition of startle. While the effects of species and genetic background on these phenotypes remain difficult to distinguish, our findings suggest that BACE1’s role in myelination and some sensorimotor functions is consistent between mice and rats and may be conserved in other species. Other phenotypes differ between these models, suggesting that some effects of BACE1 inhibition vary with the biological context (e.g. species or background strain).
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26
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Becker-Pauly C, Pietrzik CU. The Metalloprotease Meprin β Is an Alternative β-Secretase of APP. Front Mol Neurosci 2017; 9:159. [PMID: 28105004 PMCID: PMC5215381 DOI: 10.3389/fnmol.2016.00159] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 12/09/2016] [Indexed: 01/08/2023] Open
Abstract
The membrane bound metalloprotease meprin β is important for collagen fibril assembly in connective tissue formation and for the detachment of the intestinal mucus layer for proper barrier function. Recent proteomic studies revealed dozens of putative new substrates of meprin β, including the amyloid precursor protein (APP). It was shown that APP is cleaved by meprin β in distinct ways, either at the β-secretase site resulting in increased levels of Aβ peptides, or at the N-terminus releasing 11 kDa, and 20 kDa peptide fragments. The latter event was discussed to be rather neuroprotective, whereas the ectodomain shedding of APP by meprin β reminiscent to BACE-1 is in line with the amyloid hypothesis of Alzheimer's disease, promoting neurodegeneration. The N-terminal 11 kDa and 20 kDa peptide fragments represent physiological cleavage products, since they are found in human brains under different diseased or non-diseased states, whereas these fragments are completely missing in brains of meprin β knock-out animals. Meprin β is not only a sheddase of adhesion molecules, such as APP, but was additionally demonstrated to cleave within the prodomain of ADAM10. Activated ADAM10, the α-secretase of APP, is then able to shed meprin β from the cell surface thereby abolishing the β-secretase activity. All together meprin β seems to be a novel player in APP processing events, even influencing other enzymes involved in APP cleavage.
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Affiliation(s)
- Christoph Becker-Pauly
- Unit for Degradomics of the Protease Web, Institute of Biochemistry, University of Kiel Kiel, Germany
| | - Claus U Pietrzik
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg-University Mainz Mainz, Germany
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27
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Wu Q, Sun JX, Song XH, Wang J, Xiong CQ, Teng FX, Gao CX. Blocking beta 2-adrenergic receptor inhibits dendrite ramification in a mouse model of Alzheimer's disease. Neural Regen Res 2017; 12:1499-1506. [PMID: 29089997 PMCID: PMC5649472 DOI: 10.4103/1673-5374.215261] [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] [Indexed: 12/24/2022] Open
Abstract
Dendrite ramification affects synaptic strength and plays a crucial role in memory. Previous studies revealed a correlation between beta 2-adrenergic receptor dysfunction and Alzheimer's disease (AD), although the mechanism involved is still poorly understood. The current study investigated the potential effect of the selective β2-adrenergic receptor antagonist, ICI 118551 (ICI), on Aβ deposits and AD-related cognitive impairment. Morris water maze test results demonstrated that the performance of AD-transgenic (TG) mice treated with ICI (AD-TG/ICI) was significantly poorer compared with NaCl-treated AD-TG mice (AD-TG/NaCl), suggesting that β2-adrenergic receptor blockage by ICI might reduce the learning and memory abilities of mice. Golgi staining and immunohistochemical staining revealed that blockage of the β2-adrenergic receptor by ICI treatment decreased the number of dendritic branches, and ICI treatment in AD-TG mice decreased the expression of hippocampal synaptophysin and synapsin 1. Western blot assay results showed that the blockage of β2-adrenergic receptor increased amyloid-β accumulation by downregulating hippocampal α-secretase activity and increasing the phosphorylation of amyloid precursor protein. These findings suggest that blocking the β2-adrenergic receptor inhibits dendrite ramification of hippocampal neurons in a mouse model of AD.
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Affiliation(s)
- Qin Wu
- Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical College, Xuzhou, Jiangsu Province, China.,College of Medical Technology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu Province, China
| | - Jin-Xia Sun
- College of Medical Technology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu Province, China
| | - Xiang-He Song
- College of Medical Technology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu Province, China
| | - Jing Wang
- College of Medical Technology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu Province, China
| | - Cun-Quan Xiong
- College of Medical Technology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu Province, China
| | - Fei-Xiang Teng
- College of Medical Technology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu Province, China
| | - Cui-Xiang Gao
- College of Medical Technology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu Province, China
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28
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Chai GS, Wang YY, Zhu D, Yasheng A, Zhao P. Activation of β 2-adrenergic receptor promotes dendrite ramification and spine generation in APP/PS1 mice. Neurosci Lett 2016; 636:158-164. [PMID: 27838449 DOI: 10.1016/j.neulet.2016.11.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 11/08/2016] [Accepted: 11/08/2016] [Indexed: 01/21/2023]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder, and currently there is no effective cure for this devastating disease. Decreases in the levels of β2-adrenoceptor (β2-AR) and norepinephrine have been reported in several regions of AD brains. The activation of β2AR can prevent the amyloid β (Aβ)-mediated inhibition of LTP (Long-term potentiation), but the mechanism is not fully understood. Here, we used APP/PS1 mice to study whether the activation of β2AR could remodel synaptic and/or dendritic plasticity. We found that the activation of β2AR by Clenbuterol (Clen) ameliorated memory deficits and promoted dendrite ramification and spine generation in hippocampal CA1 neurons, which was accompanied by the upregulation of postsynaptic density protein 95 (PSD95), synapsin 1 and synaptophysin. Conversely, the inhibition of β2AR by a siRNA blocked the Clen-induced increase in dendrite ramification and dendritic spines in primary hippocampal neurons. Furthermore, the activation of β2AR decreased cerebral amyloid plaques through the up-regulation of α-secretase activity and by decreasing the phosphorylation of APP at Thr668. Based on the roles of β2AR in dendrite ramification and spine generation, memory deficits and AD pathogenesis, compounds designed to activate β2AR might shed light on the cure of AD.
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Affiliation(s)
- Gao-Shang Chai
- Department of Basic Medicine, Wuxi Medical School, Jiangnan University, Wuxi, Jiangsu Province, 214122, PR China.
| | - Yang-Yang Wang
- Department of Basic Medicine, Wuxi Medical School, Jiangnan University, Wuxi, Jiangsu Province, 214122, PR China
| | - Dan Zhu
- Department of Basic Medicine, Wuxi Medical School, Jiangnan University, Wuxi, Jiangsu Province, 214122, PR China
| | - Amina Yasheng
- Department of Basic Medicine, Wuxi Medical School, Jiangnan University, Wuxi, Jiangsu Province, 214122, PR China
| | - Peng Zhao
- Department of Basic Medicine, Wuxi Medical School, Jiangnan University, Wuxi, Jiangsu Province, 214122, PR China.
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29
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Brain-Wide Insulin Resistance, Tau Phosphorylation Changes, and Hippocampal Neprilysin and Amyloid-β Alterations in a Monkey Model of Type 1 Diabetes. J Neurosci 2016; 36:4248-58. [PMID: 27076423 DOI: 10.1523/jneurosci.4640-14.2016] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 02/02/2016] [Indexed: 02/08/2023] Open
Abstract
UNLABELLED Epidemiological findings suggest that diabetic individuals are at a greater risk for developing Alzheimer's disease (AD). To examine the mechanisms by which diabetes mellitus (DM) may contribute to AD pathology in humans, we examined brain tissue from streptozotocin-treated type 1 diabetic adult male vervet monkeys receiving twice-daily exogenous insulin injections for 8-20 weeks. We found greater inhibitory phosphorylation of insulin receptor substrate 1 in each brain region examined of the diabetic monkeys when compared with controls, consistent with a pattern of brain insulin resistance that is similar to that reported in the human AD brain. Additionally, a widespread increase in phosphorylated tau was seen, including brain areas vulnerable in AD, as well as relatively spared structures, such as the cerebellum. An increase in active ERK1/2 was also detected, consistent with DM leading to changes in tau-kinase activity broadly within the brain. In contrast to these widespread changes, we found an increase in soluble amyloid-β (Aβ) levels that was restricted to the temporal lobe, with the greatest increase seen in the hippocampus. Consistent with this localized Aβ increase, a hippocampus-restricted decrease in the protein and mRNA for the Aβ-degrading enzyme neprilysin (NEP) was found, whereas various Aβ-clearing and -degrading proteins were unchanged. Thus, we document multiple biochemical changes in the insulin-controlled DM monkey brain that can link DM with the risk of developing AD, including dysregulation of the insulin-signaling pathway, changes in tau phosphorylation, and a decrease in NEP expression in the hippocampus that is coupled with a localized increase in Aβ. SIGNIFICANCE STATEMENT Given that diabetes mellitus (DM) appears to increase the risk of developing Alzheimer's disease (AD), understanding the mechanisms by which DM promotes AD is important. We report that DM in a nonhuman primate brain leads to changes in the levels or posttranslational processing of proteins central to AD pathobiology, including tau, amyloid-β (Aβ), and the Aβ-degrading protease neprilysin. Additional evidence from this model suggests that alterations in brain insulin signaling occurred that are reminiscent of insulin signaling pathway changes seen in human AD. Thus, in an in vivo model highly relevant to humans, we show multiple alterations in the brain resulting from DM that are mechanistically linked to AD risk.
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30
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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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31
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Schönherr C, Bien J, Isbert S, Wichert R, Prox J, Altmeppen H, Kumar S, Walter J, Lichtenthaler SF, Weggen S, Glatzel M, Becker-Pauly C, Pietrzik CU. Generation of aggregation prone N-terminally truncated amyloid β peptides by meprin β depends on the sequence specificity at the cleavage site. Mol Neurodegener 2016; 11:19. [PMID: 26895626 PMCID: PMC4759862 DOI: 10.1186/s13024-016-0084-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 02/08/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The metalloprotease meprin β cleaves the Alzheimer's Disease (AD) relevant amyloid precursor protein (APP) as a β-secretase reminiscent of BACE-1, however, predominantly generating N-terminally truncated Aβ2-x variants. RESULTS Herein, we observed increased endogenous sAPPα levels in the brains of meprin β knock-out (ko) mice compared to wild-type controls. We further analyzed the cellular interaction of APP and meprin β and found that cleavage of APP by meprin β occurs prior to endocytosis. The N-terminally truncated Aβ2-40 variant shows increased aggregation propensity compared to Aβ1-40 and acts even as a seed for Aβ1-40 aggregation. Additionally, we observed that different APP mutants affect the catalytic properties of meprin β and that, interestingly, meprin β is unable to generate N-terminally truncated Aβ peptides from Swedish mutant APP (APPswe). CONCLUSION Concluding, we propose that meprin β may be involved in the generation of N-terminally truncated Aβ2-x peptides of APP, but acts independently from BACE-1.
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Affiliation(s)
- Caroline Schönherr
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Jessica Bien
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Simone Isbert
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Rielana Wichert
- Institute of Biochemistry, Unit for Degradomics of the Protease Web, Christian-Albrechts-University, Otto-Hahn-Platz 9, 24118, Kiel, Germany
| | - Johannes Prox
- Institute of Biochemistry, Unit for Degradomics of the Protease Web, Christian-Albrechts-University, Otto-Hahn-Platz 9, 24118, Kiel, Germany
| | - Hermann Altmeppen
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Sathish Kumar
- Department of Neurology, Molecular Cell Biology, University of Bonn, 53127, Bonn, Germany
| | - Jochen Walter
- Department of Neurology, Molecular Cell Biology, University of Bonn, 53127, Bonn, Germany
| | - Stefan F Lichtenthaler
- German Center for Neurodegenerative Diseases (DZNE) and Neuroproteomics, Klinikum rechts der Isar, Technische Universität München, 81675, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Sascha Weggen
- Department of Neuropathology, Heinrich Heine University, 40225, Duesseldorf, Germany
| | - Markus Glatzel
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Christoph Becker-Pauly
- Institute of Biochemistry, Unit for Degradomics of the Protease Web, Christian-Albrechts-University, Otto-Hahn-Platz 9, 24118, Kiel, Germany.
| | - Claus U Pietrzik
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Duesbergweg 6, 55128, Mainz, Germany.
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32
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Ghosh AK, Cárdenas EL, Osswald HL. The Design, Development, and Evaluation of BACE1 Inhibitors for the Treatment of Alzheimer’s Disease. TOPICS IN MEDICINAL CHEMISTRY 2016. [DOI: 10.1007/7355_2016_16] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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33
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Chai GS, Wang YY, Yasheng A, Zhao P. Beta 2-adrenergic receptor activation enhances neurogenesis in Alzheimer's disease mice. Neural Regen Res 2016; 11:1617-1624. [PMID: 27904493 PMCID: PMC5116841 DOI: 10.4103/1673-5374.193241] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Impaired hippocampal neurogenesis is one of the early pathological features of Alzheimer's disease. Enhancing adult hippocampal neurogenesis has been pursued as a potential therapeutic strategy for Alzheimer's disease. Recent studies have demonstrated that environmental novelty activates β2-adrenergic signaling and prevents the memory impairment induced by amyloid-β oligomers. Here, we hypothesized that β2-adrenoceptor activation would enhance neurogenesis and ameliorate memory deficits in Alzheimer's disease. To test this hypothesis, we investigated the effects and mechanisms of action of β2-adrenoceptor activation on neurogenesis and memory in amyloid precursor protein/presenilin 1 (APP/PS1) mice using the agonist clenbuterol (intraperitoneal injection, 2 mg/kg). We found that β2-adrenoceptor activation enhanced hippocampal neurogenesis, ameliorated memory deficits, and increased dendritic branching and the density of dendritic spines. These effects were associated with the upregulation of postsynaptic density 95, synapsin 1 and synaptophysin in APP/PS1 mice. Furthermore, β2-adrenoceptor activation decreased cerebral amyloid plaques by decreasing APP phosphorylation at Thr668. These findings suggest that β2-adrenoceptor activation enhances neurogenesis and ameliorates memory deficits in APP/PS1 mice.
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Affiliation(s)
- Gao-Shang Chai
- Department of Basic Medicine, Wuxi Medical School, Jiangnan University, Wuxi, Jiangsu Province, China
| | - Yang-Yang Wang
- Department of Basic Medicine, Wuxi Medical School, Jiangnan University, Wuxi, Jiangsu Province, China
| | - Amina Yasheng
- Department of Basic Medicine, Wuxi Medical School, Jiangnan University, Wuxi, Jiangsu Province, China
| | - Peng Zhao
- Department of Basic Medicine, Wuxi Medical School, Jiangnan University, Wuxi, Jiangsu Province, China
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34
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Jiang Y, Rigoglioso A, Peterhoff CM, Pawlik M, Sato Y, Bleiwas C, Stavrides P, Smiley JF, Ginsberg SD, Mathews PM, Levy E, Nixon RA. Partial BACE1 reduction in a Down syndrome mouse model blocks Alzheimer-related endosomal anomalies and cholinergic neurodegeneration: role of APP-CTF. Neurobiol Aging 2015; 39:90-8. [PMID: 26923405 DOI: 10.1016/j.neurobiolaging.2015.11.013] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 11/17/2015] [Accepted: 11/23/2015] [Indexed: 11/30/2022]
Abstract
β-amyloid precursor protein (APP) and amyloid beta peptide (Aβ) are strongly implicated in Alzheimer's disease (AD) pathogenesis, although recent evidence has linked APP-βCTF generated by BACE1 (β-APP cleaving enzyme 1) to the development of endocytic abnormalities and cholinergic neurodegeneration in early AD. We show that partial BACE1 genetic reduction prevents these AD-related pathological features in the Ts2 mouse model of Down syndrome. Partially reducing BACE1 by deleting one BACE1 allele blocked development of age-related endosome enlargement in the medial septal nucleus, cerebral cortex, and hippocampus and loss of choline acetyltransferase (ChAT)-positive medial septal nucleus neurons. BACE1 reduction normalized APP-βCTF elevation but did not alter Aβ40 and Aβ42 peptide levels in brain, supporting a critical role in vivo for APP-βCTF in the development of these abnormalities. Although ameliorative effects of BACE1 inhibition on β-amyloidosis and synaptic proteins levels have been previously noted in AD mouse models, our results highlight the additional potential value of BACE1 modulation in therapeutic targeting of endocytic dysfunction and cholinergic neurodegeneration in Down syndrome and AD.
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Affiliation(s)
- Ying Jiang
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA; Department of Psychiatry, NYU Langone Medical Center, New York, NY, USA
| | - Andrew Rigoglioso
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA
| | | | - Monika Pawlik
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA
| | - Yutaka Sato
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA
| | - Cynthia Bleiwas
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA
| | - Philip Stavrides
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA
| | - John F Smiley
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA; Department of Psychiatry, NYU Langone Medical Center, New York, NY, USA
| | - Stephen D Ginsberg
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA; Department of Psychiatry, NYU Langone Medical Center, New York, NY, USA; Department of Neuroscience & Physiology, NYU Langone Medical Center, New York, NY, USA
| | - Paul M Mathews
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA; Department of Psychiatry, NYU Langone Medical Center, New York, NY, USA
| | - Efrat Levy
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA; Department of Psychiatry, NYU Langone Medical Center, New York, NY, USA; Department of Biochemistry and Molecular Pharmacology, NYU Langone Medical Center, New York, NY, USA
| | - Ralph A Nixon
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, NY, USA; Department of Psychiatry, NYU Langone Medical Center, New York, NY, USA; Department of Cell Biology, NYU Langone Medical Center, New York, NY, USA.
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Devi L, Ohno M. Effects of BACE1 haploinsufficiency on APP processing and Aβ concentrations in male and female 5XFAD Alzheimer mice at different disease stages. Neuroscience 2015; 307:128-37. [PMID: 26314636 DOI: 10.1016/j.neuroscience.2015.08.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 08/14/2015] [Accepted: 08/18/2015] [Indexed: 11/28/2022]
Abstract
β-Site APP-cleaving enzyme 1 (BACE1) initiates the generation of amyloid-β (Aβ), thus representing a prime therapeutic target for Alzheimer's disease (AD). Previous work including ours has used BACE1 haploinsufficiency (BACE1(+/-); i.e., 50% reduction) as a therapeutic relevant model to evaluate the efficacy of partial β-secretase inhibition. However, it is unclear whether the extent of Aβ reductions in amyloid precursor protein (APP) transgenic mice with BACE1(+/-) gene ablation may vary with sex or disease progression. Here, we compared the impacts of BACE1 haploinsufficiency on Aβ concentrations and APP processing in 5XFAD Alzheimer mice (1) between males and females and (2) between different stages with moderate and robust Aβ accumulation. First, male and female 5XFAD mice at 6-7 months of age showed equivalent levels of Aβ, BACE1, full-length APP and its metabolites. BACE1 haploinsufficiency significantly lowered soluble Aβ oligomers, total Aβ42 levels and plaque burden in 5XFAD mouse brains irrespective of sex. Furthermore, there was no sex difference in reductions of β-cleavage products of APP (C99 and sAPPβ) found in BACE1(+/-)·5XFAD mice relative to BACE1(+/+)·5XFAD controls. Meanwhile, APP and sAPPα levels in BACE1(+/-)·5XFAD mice were higher than those of 5XFAD controls regardless of sex. Based on these observations, we next combined male and female data to examine the effects of BACE1 haploinsufficiency in 5XFAD mice at 12-14 months of age, as compared with those in 6-7-month-old 5XFAD mice. Oligomeric Aβ and C99 levels were dramatically elevated in older 5XFAD mice. Although the β-metabolites of APP were significantly reduced by BACE1 haploinsufficiency in both age groups, high levels of these toxic amyloidogenic fragments remained in 12-14-month-old BACE1(+/-)·5XFAD mice. The present findings are consistent with our previous behavioral data showing that BACE1 haploinsufficiency rescues memory deficits in 5XFAD mice irrespective of sex but only in the younger age group.
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Affiliation(s)
- L Devi
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA
| | - M Ohno
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA; Department of Psychiatry, New York University Langone Medical Center, New York, NY, USA.
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Mishra P, Ayyannan SR, Panda G. Perspectives on Inhibiting β-Amyloid Aggregation through Structure-Based Drug Design. ChemMedChem 2015; 10:1467-74. [DOI: 10.1002/cmdc.201500215] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 06/30/2015] [Indexed: 12/24/2022]
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Ellis CR, Shen J. pH-Dependent Population Shift Regulates BACE1 Activity and Inhibition. J Am Chem Soc 2015; 137:9543-6. [PMID: 26186663 DOI: 10.1021/jacs.5b05891] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACE1, a major therapeutic target for treatment of Alzheimer's disease, functions within a narrow pH range. Despite tremendous effort and progress in the development of BACE1 inhibitors, details of the underlying pH-dependent regulatory mechanism remain unclear. Here we elucidate the pH-dependent conformational mechanism that regulates BACE1 activity using continuous constant-pH molecular dynamics (MD). The simulations reveal that BACE1 mainly occupies three conformational states and that the relative populations of the states shift according to pH. At intermediate pH, when the catalytic dyad is monoprotonated, a binding-competent state is highly populated, while at low and high pH a Tyr-inhibited state is dominant. Our data provide strong evidence supporting conformational selection as a major mechanism for substrate and peptide-inhibitor binding. These new insights, while consistent with experiment, greatly extend the knowledge of BACE1 and have implications for further optimization of inhibitors and understanding potential side effects of targeting BACE1. Finally, the work highlights the importance of properly modeling protonation states in MD simulations.
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Affiliation(s)
- Christopher R Ellis
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201, United States
| | - Jana Shen
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201, United States
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Swedish mutant APP-based BACE1 binding site peptide reduces APP β-cleavage and cerebral Aβ levels in Alzheimer's mice. Sci Rep 2015; 5:11322. [PMID: 26091071 PMCID: PMC4473678 DOI: 10.1038/srep11322] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 05/14/2015] [Indexed: 11/08/2022] Open
Abstract
BACE1 initiates amyloid-β (Aβ) generation and the resultant cerebral amyloidosis, as a characteristic of Alzheimer's disease (AD). Thus, inhibition of BACE1 has been the focus of a large body of research. The most recent clinical trials highlight the difficulty involved in this type of anti-AD therapy as evidenced by side effects likely due to the ubiquitous nature of BACE1, which cleaves multiple substrates. The human Swedish mutant form of amyloid protein precursor (APPswe) has been shown to possess a higher affinity for BACE1 compared to wild-type APP (APPwt). We pursued a new approach wherein harnessing this greater affinity to modulate BACE1 APP processing activity. We found that one peptide derived from APPswe, containing the β-cleavage site, strongly inhibits BACE1 activity and thereby reduces Aβ production. This peptide, termed APPswe BACE1 binding site peptide (APPsweBBP), was further conjugated to the fusion domain of the HIV-1 Tat protein (TAT) at the C-terminus to facilitate its biomembrane-penetrating activity. APPwt and APPswe over-expressing CHO cells treated with this TAT-conjugated peptide resulted in a marked reduction of Aβ and a significant increase of soluble APPα. Intraperitoneal administration of this peptide to 5XFAD mice markedly reduced β-amyloid deposits as well as improved hippocampal-dependent learning and memory.
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Ghosh AK, Osswald HL. BACE1 (β-secretase) inhibitors for the treatment of Alzheimer's disease. Chem Soc Rev 2015; 43:6765-813. [PMID: 24691405 DOI: 10.1039/c3cs60460h] [Citation(s) in RCA: 233] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACE1 (β-secretase, memapsin 2, Asp2) has emerged as a promising target for the treatment of Alzheimer's disease. BACE1 is an aspartic protease which functions in the first step of the pathway leading to the production and deposition of amyloid-β peptide (Aβ). Its gene deletion showed only mild phenotypes. BACE1 inhibition has direct implications in the Alzheimer's disease pathology without largely affecting viability. However, inhibiting BACE1 selectively in vivo has presented many challenges to medicinal chemists. Since its identification in 2000, inhibitors covering many different structural classes have been designed and developed. These inhibitors can be largely classified as either peptidomimetic or non-peptidic inhibitors. Progress in these fields resulted in inhibitors that contain many targeted drug-like characteristics. In this review, we describe structure-based design strategies and evolution of a wide range of BACE1 inhibitors including compounds that have been shown to reduce brain Aβ, rescue the cognitive decline in transgenic AD mice and inhibitor drug candidates that are currently in clinical trials.
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Affiliation(s)
- Arun K Ghosh
- Department of Chemistry and Department of Medicinal Chemistry, Purdue University, West Lafayette, IN 47907, USA
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Psotta L, Rockahr C, Gruss M, Kirches E, Braun K, Lessmann V, Bock J, Endres T. Impact of an additional chronic BDNF reduction on learning performance in an Alzheimer mouse model. Front Behav Neurosci 2015; 9:58. [PMID: 25852506 PMCID: PMC4367180 DOI: 10.3389/fnbeh.2015.00058] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 02/18/2015] [Indexed: 01/01/2023] Open
Abstract
There is increasing evidence that brain-derived neurotrophic factor (BDNF) plays a crucial role in Alzheimer’s disease (AD) pathology. A number of studies demonstrated that AD patients exhibit reduced BDNF levels in the brain and the blood serum, and in addition, several animal-based studies indicated a potential protective effect of BDNF against Aβ-induced neurotoxicity. In order to further investigate the role of BDNF in the etiology of AD, we created a novel mouse model by crossing a well-established AD mouse model (APP/PS1) with a mouse exhibiting a chronic BDNF deficiency (BDNF+/−). This new triple transgenic mouse model enabled us to further analyze the role of BDNF in AD in vivo. We reasoned that in case BDNF has a protective effect against AD pathology, an AD-like phenotype in our new mouse model should occur earlier and/or in more severity than in the APP/PS1-mice. Indeed, the behavioral analysis revealed that the APP/PS1-BDNF+/−-mice show an earlier onset of learning impairments in a two-way active avoidance task in comparison to APP/PS1- and BDNF+/−-mice. However in the Morris water maze (MWM) test, we could not observe an overall aggrevated impairment in spatial learning and also short-term memory in an object recognition task remained intact in all tested mouse lines. In addition to the behavioral experiments, we analyzed the amyloid plaque pathology in the APP/PS1 and APP/PS1-BDNF+/−-mice and observed a comparable plaque density in the two genotypes. Moreover, our results revealed a higher plaque density in prefrontal cortical compared to hippocampal brain regions. Our data reveal that higher cognitive tasks requiring the recruitment of cortical networks appear to be more severely affected in our new mouse model than learning tasks requiring mainly sub-cortical networks. Furthermore, our observations of an accelerated impairment in active avoidance learning in APP/PS1-BDNF+/−-mice further supports the hypothesis that BDNF deficiency amplifies AD-related cognitive dysfunctions.
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Affiliation(s)
- Laura Psotta
- Institute of Physiology, Medical Faculty, Otto-von-Guericke-University Magdeburg Magdeburg, Germany
| | - Carolin Rockahr
- Department of Zoology/Developmental Neurobiology, Institute of Biology, Faculty of Natural Sciences, Otto-von-Guericke University Magdeburg Magdeburg, Germany
| | - Michael Gruss
- Department of Zoology/Developmental Neurobiology, Institute of Biology, Faculty of Natural Sciences, Otto-von-Guericke University Magdeburg Magdeburg, Germany
| | - Elmar Kirches
- Institute of Neuropathology, Faculty of Medicine, Otto-von-Guericke University Magdeburg Magdeburg, Germany
| | - Katharina Braun
- Department of Zoology/Developmental Neurobiology, Institute of Biology, Faculty of Natural Sciences, Otto-von-Guericke University Magdeburg Magdeburg, Germany ; Center for Behavioral Brain Sciences (CBBS), Otto-von-Guericke University Magdeburg Magdeburg, Germany
| | - Volkmar Lessmann
- Institute of Physiology, Medical Faculty, Otto-von-Guericke-University Magdeburg Magdeburg, Germany ; Center for Behavioral Brain Sciences (CBBS), Otto-von-Guericke University Magdeburg Magdeburg, Germany
| | - Jörg Bock
- Department of Zoology/Developmental Neurobiology, Institute of Biology, Faculty of Natural Sciences, Otto-von-Guericke University Magdeburg Magdeburg, Germany ; Center for Behavioral Brain Sciences (CBBS), Otto-von-Guericke University Magdeburg Magdeburg, Germany
| | - Thomas Endres
- Institute of Physiology, Medical Faculty, Otto-von-Guericke-University Magdeburg Magdeburg, Germany ; Center for Behavioral Brain Sciences (CBBS), Otto-von-Guericke University Magdeburg Magdeburg, Germany
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Kandalepas PC, Vassar R. The normal and pathologic roles of the Alzheimer's β-secretase, BACE1. Curr Alzheimer Res 2015; 11:441-9. [PMID: 24893886 DOI: 10.2174/1567205011666140604122059] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 01/15/2014] [Accepted: 01/25/2014] [Indexed: 01/18/2023]
Abstract
As the most common neurodegenerative disease, therapeutic avenues for the treatment and prevention of Alzheimer's Disease are highly sought after. The aspartic protease BACE1 is the initiator enzyme for the formation of Aβ, a major constituent of amyloid plaques that represent one of the hallmark pathological features of this disorder. Thus, targeting BACE1 for disease-modifying AD therapies represents a rationale approach. The collective knowledge acquired from investigations of BACE1 deletion mutants and characterization of BACE1 substrates has downstream significance not only for the discovery of AD drug therapies but also for predicting side effects of BACE1 inhibition. Here we discuss the identification and validation of BACE1 as the β-secretase implicated in AD, in addition to information regarding BACE1 cell biology, localization, substrates and potential physiological functions derived from BACE1 knockout models.
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Affiliation(s)
| | - Robert Vassar
- Northwestern University, Feinberg School of Medicine, Department of Cell & Molecular Biology, 300 E. Superior, Tarry 8-713, IL 60611, Chicago.
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Hook G, Yu J, Toneff T, Kindy M, Hook V. Brain pyroglutamate amyloid-β is produced by cathepsin B and is reduced by the cysteine protease inhibitor E64d, representing a potential Alzheimer's disease therapeutic. J Alzheimers Dis 2015; 41:129-49. [PMID: 24595198 DOI: 10.3233/jad-131370] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Pyroglutamate amyloid-β peptides (pGlu-Aβ) are particularly pernicious forms of amyloid-β peptides (Aβ) present in Alzheimer's disease (AD) brains. pGlu-Aβ peptides are N-terminally truncated forms of full-length Aβ peptides (flAβ(1-40/42)) in which the N-terminal glutamate is cyclized to pyroglutamate to generate pGlu-Aβ(3-40/42). β-secretase cleavage of amyloid-β precursor protein (AβPP) produces flAβ(1-40/42), but it is not yet known whether the β-secretase BACE1 or the alternative β-secretase cathepsin B (CatB) participate in the production of pGlu-Aβ. Therefore, this study examined the effects of gene knockout of these proteases on brain pGlu-Aβ levels in transgenic AβPPLon mice, which express AβPP isoform 695 and have the wild-type (wt) β-secretase activity found in most AD patients. Knockout or overexpression of the CatB gene reduced or increased, respectively, pGlu-Aβ(3-40/42), flAβ(1-40/42), and pGlu-Aβ plaque load, but knockout of the BACE1 gene had no effect on those parameters in the transgenic mice. Treatment of AβPPLon mice with E64d, a cysteine protease inhibitor of CatB, also reduced brain pGlu-Aβ(3-42), flAβ(1-40/42), and pGlu-Aβ plaque load. Treatment of neuronal-like chromaffin cells with CA074Me, an inhibitor of CatB, resulted in reduced levels of pGlu-Aβ(3-40) released from the activity-dependent, regulated secretory pathway. Moreover, CatB knockout and E64d treatment has been previously shown to improve memory deficits in the AβPPLon mice. These data illustrate the role of CatB in producing pGlu-Aβ and flAβ that participate as key factors in the development of AD. The advantages of CatB inhibitors, especially E64d and its derivatives, as alternatives to BACE1 inhibitors in treating AD patients are discussed.
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Affiliation(s)
- Gregory Hook
- American Life Science Pharmaceuticals, La Jolla, CA, USA
| | - Jin Yu
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA Ralph H. Johnson VA Medical Center, Charleston, SC, USA
| | - Thomas Toneff
- Skaggs School of Pharmacy and Pharmaceutical Sciences, Departments of Neurosciences and Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Mark Kindy
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA Ralph H. Johnson VA Medical Center, Charleston, SC, USA
| | - Vivian Hook
- Skaggs School of Pharmacy and Pharmaceutical Sciences, Departments of Neurosciences and Pharmacology, University of California, San Diego, La Jolla, CA, USA
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43
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Georgievska B, Gustavsson S, Lundkvist J, Neelissen J, Eketjäll S, Ramberg V, Bueters T, Agerman K, Juréus A, Svensson S, Berg S, Fälting J, Lendahl U. Revisiting the peripheral sink hypothesis: inhibiting BACE1 activity in the periphery does not alter β-amyloid levels in the CNS. J Neurochem 2014; 132:477-86. [PMID: 25156639 DOI: 10.1111/jnc.12937] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 08/03/2014] [Indexed: 11/28/2022]
Abstract
Aggregation of amyloid beta (Aβ) peptides and the subsequent neural plaque formation is a central aspect of Alzheimer's disease. Various strategies to reduce Aβ load in the brain are therefore intensely pursued. It has been hypothesized that reducing Aβ peptides in the periphery, that is in organs outside the brain, would be a way to diminish Aβ levels and plaque load in the brain. In this report, we put this peripheral sink hypothesis to test by investigating how selective inhibition of Aβ production in the periphery using a β-secretase (BACE)1 inhibitor or reduced BACE1 gene dosage affects Aβ load in the brain. Selective inhibition of peripheral BACE1 activity in wild-type mice or mice over-expressing amyloid precursor protein (APPswe transgenic mice; Tg2576) reduced Aβ levels in the periphery but not in the brain, not even after chronic treatment over several months. In contrast, a BACE1 inhibitor with improved brain disposition reduced Aβ levels in both brain and periphery already after acute dosing. Mice heterozygous for BACE1, displayed a 62% reduction in plasma Aβ40, whereas brain Aβ40 was only lowered by 11%. These data suggest that reduction of Aβ in the periphery is not sufficient to reduce brain Aβ levels and that BACE1 is not the rate-limiting enzyme for Aβ processing in the brain. This provides evidence against the peripheral sink hypothesis and suggests that a decrease in Aβ via BACE1 inhibition would need to be carried out in the brain. Aggregation of amyloid beta (Aβ) peptides in the brain is a central aspect of Alzheimer's disease. In this study, we demonstrate that inhibition of Aβ formation by BACE1 inhibitors needs to be carried out in the brain and that reduction of Aβ in the periphery is not sufficient to reduce brain Aβ levels. This information is useful for developing future Aβ-targeting therapies for Alzheimer's disease.
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Mori T, Koyama N, Segawa T, Maeda M, Maruyama N, Kinoshita N, Hou H, Tan J, Town T. Methylene blue modulates β-secretase, reverses cerebral amyloidosis, and improves cognition in transgenic mice. J Biol Chem 2014; 289:30303-30317. [PMID: 25157105 DOI: 10.1074/jbc.m114.568212] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Amyloid precursor protein (APP) proteolysis is required for production of amyloid-β (Aβ) peptides that comprise β-amyloid plaques in the brains of patients with Alzheimer disease (AD). Here, we tested whether the experimental agent methylene blue (MB), used for treatment of methemoglobinemia, might improve AD-like pathology and behavioral deficits. We orally administered MB to the aged transgenic PSAPP mouse model of cerebral amyloidosis and evaluated cognitive function and cerebral amyloid pathology. Beginning at 15 months of age, animals were gavaged with MB (3 mg/kg) or vehicle once daily for 3 months. MB treatment significantly prevented transgene-associated behavioral impairment, including hyperactivity, decreased object recognition, and defective spatial working and reference memory, but it did not alter nontransgenic mouse behavior. Moreover, brain parenchymal and cerebral vascular β-amyloid deposits as well as levels of various Aβ species, including oligomers, were mitigated in MB-treated PSAPP mice. These effects occurred with inhibition of amyloidogenic APP proteolysis. Specifically, β-carboxyl-terminal APP fragment and β-site APP cleaving enzyme 1 protein expression and activity were attenuated. Additionally, treatment of Chinese hamster ovary cells overexpressing human wild-type APP with MB significantly decreased Aβ production and amyloidogenic APP proteolysis. These results underscore the potential for oral MB treatment against AD-related cerebral amyloidosis by modulating the amyloidogenic pathway.
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Affiliation(s)
- Takashi Mori
- Departments of Biomedical Sciences and Saitama Medical Center and University, Kawagoe, Saitama 350-8550, Japan; Departments of Pathology, Saitama Medical Center and University, Kawagoe, Saitama 350-8550, Japan,.
| | - Naoki Koyama
- Departments of Biomedical Sciences and Saitama Medical Center and University, Kawagoe, Saitama 350-8550, Japan
| | - Tatsuya Segawa
- Immuno-Biological Laboratories Co., Ltd., Fujioka, Gunma 375-0005, Japan
| | - Masahiro Maeda
- Immuno-Biological Laboratories Co., Ltd., Fujioka, Gunma 375-0005, Japan
| | - Nobuhiro Maruyama
- Immuno-Biological Laboratories Co., Ltd., Fujioka, Gunma 375-0005, Japan
| | - Noriaki Kinoshita
- Immuno-Biological Laboratories Co., Ltd., Fujioka, Gunma 375-0005, Japan
| | - Huayan Hou
- Rashid Laboratory for Developmental Neurobiology, Silver Child Development Center and University of South Florida, Tampa, Florida 33613
| | - Jun Tan
- Rashid Laboratory for Developmental Neurobiology, Silver Child Development Center and University of South Florida, Tampa, Florida 33613; Neuroimmunology Laboratory, Department of Psychiatry and Behavioral Neurosciences, Morsoni College of Medicine, University of South Florida, Tampa, Florida 33613, and
| | - Terrence Town
- Zilkha Neurogenetic Institute, Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California 90089-2821.
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45
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Pharmacological chaperones stabilize retromer to limit APP processing. Nat Chem Biol 2014; 10:443-9. [PMID: 24747528 DOI: 10.1038/nchembio.1508] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 03/21/2014] [Indexed: 11/08/2022]
Abstract
Retromer is a multiprotein complex that trafficks cargo out of endosomes. The neuronal retromer traffics the amyloid-precursor protein (APP) away from endosomes, a site where APP is cleaved into pathogenic fragments in Alzheimer's disease. Here we determined whether pharmacological chaperones can enhance retromer stability and function. First, we relied on the crystal structures of retromer proteins to help identify the 'weak link' of the complex and to complete an in silico screen of small molecules predicted to enhance retromer stability. Among the hits, an in vitro assay identified one molecule that stabilized retromer against thermal denaturation. Second, we turned to cultured hippocampal neurons, showing that this small molecule increases the levels of retromer proteins, shifts APP away from the endosome, and decreases the pathogenic processing of APP. These findings show that pharmacological chaperones can enhance the function of a multiprotein complex and may have potential therapeutic implications for neurodegenerative diseases.
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Janson J, Eketjäll S, Tunblad K, Jeppsson F, Von Berg S, Niva C, Radesäter AC, Fälting J, Visser SAG. Population PKPD modeling of BACE1 inhibitor-induced reduction in Aβ levels in vivo and correlation to in vitro potency in primary cortical neurons from mouse and guinea pig. Pharm Res 2013; 31:670-83. [PMID: 24092053 DOI: 10.1007/s11095-013-1189-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 08/09/2013] [Indexed: 12/26/2022]
Abstract
PURPOSE The aims were to quantify the in vivo time-course between the oral dose, the plasma and brain exposure and the inhibitory effect on Amyloid β (Aβ) in brain and cerebrospinal fluid, and to establish the correlation between in vitro and in vivo potency of novel β-secretase (BACE1) inhibitors. METHODS BACE1-mediated inhibition of Aβ was quantified in in vivo dose- and/or time-response studies and in vitro in SH-SY5Y cells, N2A cells, and primary cortical neurons (PCN). An indirect response model with inhibition on Aβ production rate was used to estimate unbound in vivo IC 50 in a population pharmacokinetic-pharmacodynamic modeling approach. RESULTS Estimated in vivo inhibitory potencies varied between 1 and 1,000 nM. The turnover half-life of Aβ40 in brain was predicted to be 0.5 h in mouse and 1 h in guinea pig. An excellent correlation between PCN and in vivo potency was observed. Moreover, a strong correlation in potency was found between human SH-SY5Y cells and mouse PCN, being 4.5-fold larger in SH-SY5Y cells. CONCLUSION The strong in vivo-in vitro correlation increased the confidence in using human cell lines for screening and optimization of BACE1 inhibitors. This can optimize the design and reduce the number of preclinical in vivo effect studies.
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Affiliation(s)
- Juliette Janson
- Modeling & Simulation, DMPK, Innovative Medicines CNSP AstraZeneca, SE-15185, Södertälje, Sweden,
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Butini S, Brogi S, Novellino E, Campiani G, Ghosh AK, Brindisi M, Gemma S. The structural evolution of β-secretase inhibitors: a focus on the development of small-molecule inhibitors. Curr Top Med Chem 2013; 13:1787-807. [PMID: 23931442 PMCID: PMC6034716 DOI: 10.2174/15680266113139990137] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 05/11/2013] [Indexed: 12/12/2022]
Abstract
Effective treatment of Alzheimer's disease (AD) remains a critical unmet need in medicine. The lack of useful treatment for AD led to an intense search for novel therapies based on the amyloid hypothesis, which states that amyloid β-42 (Aβ42) plays an early and crucial role in all cases of AD. β-Secretase (also known as BACE-1 β-site APP-cleaving enzyme, Asp-2 or memapsin-2) is an aspartyl protease representing the rate limiting step in the generation of Aβ peptide fragments, therefore it could represent an important target in the steady hunt for a disease-modifying treatment. Generally, β-secretase inhibitors are grouped into two families: peptidomimetic and nonpeptidomimetic inhibitors. However, irrespective of the class, serious challenges with respect to blood-brain barrier (BBB) penetration and selectivity still remain. Discovering a small molecule inhibitor of β-secretase represents an unnerving challenge but, due to its significant potential as a therapeutic target, growing efforts in this task are evident from both academic and industrial laboratories. In this frame, the rising availability of crystal structures of β-secretase-inhibitor complexes represents an invaluable opportunity for optimization. Nevertheless, beyond the inhibitory activity, the major issue of the current research approaches is about problems associated with BBB penetration and pharmacokinetic properties. This review follows the structural evolution of the early β-secretase inhibitors and gives a snap-shot of the hottest chemical templates in the literature of the last five years, showing research progress in this field.
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Affiliation(s)
- Stefania Butini
- European Research Centre for Drug Discovery and Development (NatSynDrugs), University of Siena, Italy
| | - Simone Brogi
- European Research Centre for Drug Discovery and Development (NatSynDrugs), University of Siena, Italy
| | - Ettore Novellino
- European Research Centre for Drug Discovery and Development (NatSynDrugs), University of Siena, Italy
- Dipartimento di Farmacia, University of Naples Federico II, Italy
| | - Giuseppe Campiani
- European Research Centre for Drug Discovery and Development (NatSynDrugs), University of Siena, Italy
| | - Arun K. Ghosh
- Department of Chemistry and Department of Medicinal Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Margherita Brindisi
- European Research Centre for Drug Discovery and Development (NatSynDrugs), University of Siena, Italy
| | - Sandra Gemma
- European Research Centre for Drug Discovery and Development (NatSynDrugs), University of Siena, Italy
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Mercaptoacetamide-based class II HDAC inhibitor lowers Aβ levels and improves learning and memory in a mouse model of Alzheimer's disease. Exp Neurol 2012; 239:192-201. [PMID: 23063601 DOI: 10.1016/j.expneurol.2012.10.005] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 09/11/2012] [Accepted: 10/04/2012] [Indexed: 02/04/2023]
Abstract
Histone deacetylase inhibitors (HDACIs) alter gene expression epigenetically by interfering with the normal functions of HDAC. Given their ability to decrease Aβ levels, HDACIs are a potential treatment for Alzheimer's disease (AD). However, it is unclear how HDACIs alter Aβ levels. We developed two novel HDAC inhibitors with improved pharmacological properties, such as a longer half-life and greater penetration of the blood-brain barrier: mercaptoacetamide-based class II HDACI (coded as W2) and hydroxamide-based class I and IIHDACI (coded as I2) and investigated how they affect Aβ levels and cognition. HDACI W2 decreased Aβ40 and Aβ42 in vitro. HDACI I2 also decreased Aβ40, but not Aβ42. We systematically examined the molecular mechanisms by which HDACIs W2 and I2 can decrease Aβ levels. HDACI W2 decreased gene expression of γ-secretase components and increased the Aβ degradation enzyme Mmp2. Similarly, HDACI I2 decreased expression of β- and γ-secretase components and increased mRNA levels of Aβ degradation enzymes. HDACI W2 also significantly decreased Aβ levels and rescued learning and memory deficits in aged hAPP 3xTg AD mice. Furthermore, we found that the novel HDACI W2 decreased tau phosphorylation at Thr181, an effect previously unknown for HDACIs. Collectively, these data suggest that class II HDACls may serve as a novel therapeutic strategy for AD.
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Kindy MS, Yu J, Zhu H, El-Amouri SS, Hook V, Hook GR. Deletion of the cathepsin B gene improves memory deficits in a transgenic ALZHeimer's disease mouse model expressing AβPP containing the wild-type β-secretase site sequence. J Alzheimers Dis 2012; 29:827-40. [PMID: 22337825 DOI: 10.3233/jad-2012-111604] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Therapeutic agents that improve the memory loss of Alzheimer's disease (AD) may eventually be developed if drug targets are identified that improve memory deficits in appropriate AD animal models. One such target is β-secretase which, in most AD patients, cleaves the wild-type (WT) β-secretase site sequence of the amyloid-β protein precursor (AβPP) to produce neurotoxic amyloid-β (Aβ). Thus, an animal model representing most AD patients for evaluating β-secretase effects on memory deficits is one that expresses human AβPP containing the WT β-secretase site sequence. BACE1 and cathepsin B (CatB) proteases have β-secretase activity, but gene knockout studies have not yet validated that the absence of these proteases improves memory deficits in such an animal model. This study assessed the effects of deleting these protease genes on memory deficits in the AD mouse model expressing human AβPP containing the WT β-secretase site sequence and the London γ-secretase site (AβPPWT/Lon mice). Knockout of the CatB gene in the AβPPWT/Lon mice improved memory deficits and altered the pattern of Aβ-related biomarkers in a manner consistent with CatB having WT β-secretase activity. But deletion of the BACE1 gene had no effect on these parameters in the AβPPWT/Lon mice. These data are the first to show that knockout of a putative β-secretase gene results in improved memory in an AD animal model expressing the WT β-secretase site sequence of AβPP, present in the majority of AD patients. CatB may be an effective drug target for improving memory deficits in most AD patients.
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Affiliation(s)
- Mark S Kindy
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA.
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Wise-Scira O, Xu L, Kitahara T, Perry G, Coskuner O. Amyloid-β peptide structure in aqueous solution varies with fragment size. J Chem Phys 2012; 135:205101. [PMID: 22128957 DOI: 10.1063/1.3662490] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Various fragment sizes of the amyloid-β (Aβ) peptide have been utilized to mimic the properties of the full-length Aβ peptide in solution. Among these smaller fragments, Aβ16 and Aβ28 have been investigated extensively. In this work, we report the structural and thermodynamic properties of the Aβ16, Aβ28, and Aβ42 peptides in an aqueous solution environment. We performed replica exchange molecular dynamics simulations along with thermodynamic calculations for investigating the conformational free energies, secondary and tertiary structures of the Aβ16, Aβ28, and Aβ42 peptides. The results show that the thermodynamic properties vary from each other for these peptides. Furthermore, the secondary structures in the Asp1-Lys16 and Asp1-Lys28 regions of Aβ42 cannot be completely captured by the Aβ16 and Aβ28 fragments. For example, the β-sheet structures in the N-terminal region of Aβ16 and Aβ28 are either not present or the abundance is significantly decreased in Aβ42. The α-helix and β-sheet abundances in Aβ28 and Aβ42 show trends--to some extent--with the potential of mean forces but no such trend could be obtained for Aβ16. Interestingly, Arg5 forms salt bridges with large abundances in all three peptides. The formation of a salt bridge between Asp23-Lys28 is more preferred over the Glu22-Lys28 salt bridge in Aβ28 but this trend is vice versa for Aβ42. This study shows that the Asp1-Lys16 and Asp1-Lys28 regions of the full length Aβ42 peptide cannot be completely mimicked by studying the Aβ16 and Aβ28 peptides.
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Affiliation(s)
- Olivia Wise-Scira
- The University of Texas at San Antonio, Department of Chemistry, One UTSA Circle, San Antonio, Texas 78249, USA
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