1
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Area-Gomez E, Schon EA. Towards a Unitary Hypothesis of Alzheimer's Disease Pathogenesis. J Alzheimers Dis 2024; 98:1243-1275. [PMID: 38578892 PMCID: PMC11091651 DOI: 10.3233/jad-231318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/15/2024] [Indexed: 04/07/2024]
Abstract
The "amyloid cascade" hypothesis of Alzheimer's disease (AD) pathogenesis invokes the accumulation in the brain of plaques (containing the amyloid-β protein precursor [AβPP] cleavage product amyloid-β [Aβ]) and tangles (containing hyperphosphorylated tau) as drivers of pathogenesis. However, the poor track record of clinical trials based on this hypothesis suggests that the accumulation of these peptides is not the only cause of AD. Here, an alternative hypothesis is proposed in which the AβPP cleavage product C99, not Aβ, is the main culprit, via its role as a regulator of cholesterol metabolism. C99, which is a cholesterol sensor, promotes the formation of mitochondria-associated endoplasmic reticulum (ER) membranes (MAM), a cholesterol-rich lipid raft-like subdomain of the ER that communicates, both physically and biochemically, with mitochondria. We propose that in early-onset AD (EOAD), MAM-localized C99 is elevated above normal levels, resulting in increased transport of cholesterol from the plasma membrane to membranes of intracellular organelles, such as ER/endosomes, thereby upregulating MAM function and driving pathology. By the same token, late-onset AD (LOAD) is triggered by any genetic variant that increases the accumulation of intracellular cholesterol that, in turn, boosts the levels of C99 and again upregulates MAM function. Thus, the functional cause of AD is upregulated MAM function that, in turn, causes the hallmark disease phenotypes, including the plaques and tangles. Accordingly, the MAM hypothesis invokes two key interrelated elements, C99 and cholesterol, that converge at the MAM to drive AD pathogenesis. From this perspective, AD is, at bottom, a lipid disorder.
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Affiliation(s)
- Estela Area-Gomez
- Department of Neurology, Columbia University, New York, NY, USA
- Centro de Investigaciones Biológicas “Margarita Salas”, Spanish National Research Council, Madrid, Spain
| | - Eric A. Schon
- Department of Neurology, Columbia University, New York, NY, USA
- Department of Genetics and Development>, Columbia University, New York, NY, USA
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2
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Alexander C, Li T, Hattori Y, Chiu D, Frost GR, Jonas L, Liu C, Anderson CJ, Wong E, Park L, Iadecola C, Li YM. Hypoxia Inducible Factor-1α binds and activates γ-secretase for Aβ production under hypoxia and cerebral hypoperfusion. Mol Psychiatry 2022; 27:4264-4273. [PMID: 35764706 PMCID: PMC9722522 DOI: 10.1038/s41380-022-01676-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 06/09/2022] [Accepted: 06/15/2022] [Indexed: 02/07/2023]
Abstract
Hypoxic-ischemic injury has been linked with increased risk for developing Alzheimer's disease (AD). The underlying mechanism of this association is poorly understood. Here, we report distinct roles for hypoxia-inducible factor-1α (Hif-1α) in the regulation of BACE1 and γ-secretase activity, two proteases involved in the production of amyloid-beta (Aβ). We have demonstrated that Hif-1α upregulates both BACE1 and γ-secretase activity for Aβ production in brain hypoxia-induced either by cerebral hypoperfusion or breathing 10% O2. Hif-1α binds to γ-secretase, which elevates the amount of active γ-secretase complex without affecting the level of individual subunits in hypoxic-ischemic mouse brains. Additionally, the expression of full length Hif-1α increases BACE1 and γ-secretase activity in primary neuronal culture, whereas a transcriptionally incompetent Hif-1α variant only activates γ-secretase. These findings indicate that Hif-1α transcriptionally upregulates BACE1 and nontranscriptionally activates γ-secretase for Aβ production in hypoxic-ischemic conditions. Consequently, Hif-1α-mediated Aβ production may be an adaptive response to hypoxic-ischemic injury, subsequently leading to increased risk for AD. Preventing the interaction of Hif-1α with γ-secretase may therefore be a promising therapeutic strategy for AD treatment.
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Affiliation(s)
- Courtney Alexander
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Programs of Neurosciences and Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Thomas Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Programs of Neurosciences and Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Yorito Hattori
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Danica Chiu
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Programs of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Georgia R Frost
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Programs of Neurosciences and Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Lauren Jonas
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Programs of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Chenge Liu
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Programs of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Corey J Anderson
- Programs of Neurosciences and Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Eitan Wong
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Laibaik Park
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Costantino Iadecola
- Programs of Neurosciences and Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Programs of Neurosciences and Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA.
- Programs of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA.
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3
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Chen SY, Zacharias M. An internal docking site stabilizes substrate binding to γ-secretase: Analysis by molecular dynamics simulations. Biophys J 2022; 121:2330-2344. [PMID: 35598043 PMCID: PMC9279352 DOI: 10.1016/j.bpj.2022.05.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 04/26/2022] [Accepted: 05/17/2022] [Indexed: 11/02/2022] Open
Abstract
Amyloid precursor protein (APP) is cleaved and processed sequentially by γ-secretase yielding amyloid β (Aβ) peptides of different lengths. Longer Aβ peptides are associated with the formation of neurotoxic plaques related to Alzheimer's disease. Based on the APP substrate-bound structure of γ-secretase, we investigated the enzyme-substrate interaction using molecular dynamics simulations and generated model structures that represent the sequentially cleaved intermediates during the processing reaction. The simulations indicated an internal docking site providing strong enzyme-substrate packing interaction. In the enzyme-substrate complex, it is located close to the region where the helical conformation of the substrate is interrupted and continues toward the active site in an extended conformation. The internal docking site consists of two non-polar pockets that are preferentially filled by large hydrophobic or aromatic substrate side chains to stabilize binding. Placement of smaller residues such as glycine can trigger a shift in the cleavage pattern during the simulations or results in destabilization of substrate binding. The reduced packing by smaller residues also influences the hydration of the active site and the formation of a catalytically active state. The simulations on processed substrate intermediates and a substrate G33I mutation offer an explanation of the experimentally observed relative increase of short Aβ fragment production for this mutation. In addition, studies on a substrate K28A mutation indicate that the internal docking site opposes the tendency of substrate dissociation due to a hydrophobic mismatch at the membrane boundary caused by K28 during processing and substrate movement toward the enzyme active site. The proposed internal docking site could also be useful for the specific design of new γ-secretase modulators.
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Affiliation(s)
- Shu-Yu Chen
- Physics Department and Center of Functional Protein Assemblies, Technical University of Munich, 85748 Garching, Germany
| | - Martin Zacharias
- Physics Department and Center of Functional Protein Assemblies, Technical University of Munich, 85748 Garching, Germany.
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4
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Hur JY. γ-Secretase in Alzheimer's disease. Exp Mol Med 2022; 54:433-446. [PMID: 35396575 PMCID: PMC9076685 DOI: 10.1038/s12276-022-00754-8] [Citation(s) in RCA: 151] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 01/05/2022] [Accepted: 01/20/2022] [Indexed: 12/16/2022] Open
Abstract
Alzheimer's disease (AD) is caused by synaptic and neuronal loss in the brain. One of the characteristic hallmarks of AD is senile plaques containing amyloid β-peptide (Aβ). Aβ is produced from amyloid precursor protein (APP) by sequential proteolytic cleavages by β-secretase and γ-secretase, and the polymerization of Aβ into amyloid plaques is thought to be a key pathogenic event in AD. Since γ-secretase mediates the final cleavage that liberates Aβ, γ-secretase has been widely studied as a potential drug target for the treatment of AD. γ-Secretase is a transmembrane protein complex containing presenilin, nicastrin, Aph-1, and Pen-2, which are sufficient for γ-secretase activity. γ-Secretase cleaves >140 substrates, including APP and Notch. Previously, γ-secretase inhibitors (GSIs) were shown to cause side effects in clinical trials due to the inhibition of Notch signaling. Therefore, more specific regulation or modulation of γ-secretase is needed. In recent years, γ-secretase modulators (GSMs) have been developed. To modulate γ-secretase and to understand its complex biology, finding the binding sites of GSIs and GSMs on γ-secretase as well as identifying transiently binding γ-secretase modulatory proteins have been of great interest. In this review, decades of findings on γ-secretase in AD are discussed.
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Affiliation(s)
- Ji-Yeun Hur
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
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5
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Kleffman K, Levinson G, Rose IVL, Blumenberg LM, Shadaloey SAA, Dhabaria A, Wong E, Galan-Echevarria F, Karz A, Argibay D, Von Itter R, Floristan A, Baptiste G, Eskow NM, Tranos JA, Chen J, Vega Y Saenz de Miera EC, Call M, Rogers R, Jour G, Wadghiri YZ, Osman I, Li YM, Mathews P, DeMattos R, Ueberheide B, Ruggles KV, Liddelow SA, Schneider RJ, Hernando E. Melanoma-secreted Amyloid Beta Suppresses Neuroinflammation and Promotes Brain Metastasis. Cancer Discov 2022; 12:1314-1335. [PMID: 35262173 PMCID: PMC9069488 DOI: 10.1158/2159-8290.cd-21-1006] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 12/21/2021] [Accepted: 02/18/2022] [Indexed: 11/16/2022]
Abstract
Brain metastasis is a significant cause of morbidity and mortality in multiple cancer types and represents an unmet clinical need. The mechanisms that mediate metastatic cancer growth in the brain parenchyma are largely unknown. Melanoma, which has the highest rate of brain metastasis among common cancer types, is an ideal model to study how cancer cells adapt to the brain parenchyma. Our unbiased proteomics analysis of melanoma short-term cultures revealed that proteins implicated in neurodegenerative pathologies are differentially expressed in melanoma cells explanted from brain metastases compared to those derived from extracranial metastases. We showed that melanoma cells require amyloid beta (AB) for growth and survival in the brain parenchyma. Melanoma-secreted AB activates surrounding astrocytes to a pro-metastatic, anti-inflammatory phenotype and prevents phagocytosis of melanoma by microglia. Finally, we demonstrate that pharmacological inhibition of AB decreases brain metastatic burden.
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Affiliation(s)
- Kevin Kleffman
- NYU Langone Medical Center, New York, New York, United States
| | - Grace Levinson
- NYU Langone Medical Center, New York, New York, United States
| | - Indigo V L Rose
- NYU Langone Medical Center, New York, New York, United States
| | | | | | - Avantika Dhabaria
- Proteomics Laboratory, Division of Advanced Research and Technology, NYU Langone Health, New York, New York., New York, NY, United States
| | - Eitan Wong
- Memorial Sloan Kettering Cancer Center, New York, New York, United States
| | | | - Alcida Karz
- NYU Langone Medical Center, New York, New York, United States
| | - Diana Argibay
- NYU Langone Medical Center, New York, NY, United States
| | | | | | - Gillian Baptiste
- New York University Grossman School of Medicine, New York, NY, United States
| | | | - James A Tranos
- NYU Langone Medical Center, New York, New York, United States
| | - Jenny Chen
- NYU Langone Medical Center, New York, New York, United States
| | | | - Melissa Call
- NYU Langone Medical Center, New York, New York, United States
| | - Robert Rogers
- NYU Langone Medical Center, New York, New York, United States
| | - George Jour
- New York University, New York, New York, United States
| | | | - Iman Osman
- New York University School of Medicine, New York, New York, United States
| | - Yue-Ming Li
- Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Paul Mathews
- NYU Langone Medical Center, New York, New York, United States
| | - Ronald DeMattos
- Eli Lilly (United States), Indianapolis, Indiana, United States
| | - Beatrix Ueberheide
- Proteomics Laboratory, Division of Advanced Research and Technology, NYU Langone Health, New York, New York., United States
| | - Kelly V Ruggles
- New York University Langone Medical Center, New York, United States
| | | | | | - Eva Hernando
- NYU Langone Medical Center, New York, NY, United States
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6
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Nie P, Kalidindi T, Nagle VL, Wu X, Li T, Liao GP, Frost G, Henry KE, Punzalan B, Carter LM, Lewis JS, Pillarsetty NVK, Li YM. Imaging of Cancer γ-Secretase Activity Using an Inhibitor-Based PET Probe. Clin Cancer Res 2021; 27:6145-6155. [PMID: 34475100 DOI: 10.1158/1078-0432.ccr-21-0940] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 06/18/2021] [Accepted: 08/30/2021] [Indexed: 11/16/2022]
Abstract
PURPOSE Abnormal Notch signaling promotes cancer cell growth and tumor progression in various cancers. Targeting γ-secretase, a pivotal regulator in the Notch pathway, has yielded numerous γ-secretase inhibitors (GSIs) for clinical investigation in the last 2 decades. However, GSIs have demonstrated minimal success in clinical trials in part due to the lack of specific and precise tools to assess γ-secretase activity and its inhibition in vivo. EXPERIMENTAL DESIGN We designed an imaging probe based on GSI Semagacestat structure and synthesized the radioiodine-labeled analogues [131I]- or [124I]-PN67 from corresponding trimethyl-tin precursors. Both membrane- and cell-based ligand-binding assays were performed using [131I]-PN67 to determine the binding affinity and specificity for γ-secretase in vitro. Moreover, we evaluated [124I]-PN67 by PET imaging in mammary tumor and glioblastoma mouse models. RESULTS The probe was synthesized through iodo-destannylation using chloramine-T as an oxidant with a high labeling yield and efficiency. In vitro binding results demonstrate the high specificity of this probe and its ability for target replacement study by clinical GSIs. PET imaging studies demonstrated a significant (P < 0.05) increased in the uptake of [124I]-PN67 in tumors versus blocking or sham control groups across multiple mouse models, including 4T1 allograft, MMTV-PyMT breast cancer, and U87 glioblastoma allograft. Ex vivo biodistribution and autoradiography corroborate these results, indicating γ-secretase specific tumor accumulation of [124I]-PN67. CONCLUSIONS [124I]-PN67 is a novel PET imaging agent that enables assessment of γ-secretase activity and target engagement of clinical GSIs.
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Affiliation(s)
- Pengju Nie
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York.,Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York
| | - Teja Kalidindi
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Veronica L Nagle
- Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York.,Program in Molecular Pharmacology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Xianzhong Wu
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Thomas Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York.,Program of Neurosciences, Weill Graduate School of Medical Sciences of Cornell University, New York, New York
| | - George P Liao
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York.,Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York
| | - Georgia Frost
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Kelly E Henry
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Blesida Punzalan
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Lukas M Carter
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Jason S Lewis
- Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York.,Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York.,Program in Molecular Pharmacology, Memorial Sloan Kettering Cancer Center, New York, New York
| | | | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York. .,Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York.,Program of Neurosciences, Weill Graduate School of Medical Sciences of Cornell University, New York, New York
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7
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Ledo JH, Liebmann T, Zhang R, Chang JC, Azevedo EP, Wong E, Silva HM, Troyanskaya OG, Bustos V, Greengard P. Presenilin 1 phosphorylation regulates amyloid-β degradation by microglia. Mol Psychiatry 2021; 26:5620-5635. [PMID: 32792660 PMCID: PMC7881060 DOI: 10.1038/s41380-020-0856-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 07/21/2020] [Accepted: 07/24/2020] [Indexed: 12/22/2022]
Abstract
Amyloid-β peptide (Aβ) accumulation in the brain is a hallmark of Alzheimer's Disease. An important mechanism of Aβ clearance in the brain is uptake and degradation by microglia. Presenilin 1 (PS1) is the catalytic subunit of γ-secretase, an enzyme complex responsible for the maturation of multiple substrates, such as Aβ. Although PS1 has been extensively studied in neurons, the role of PS1 in microglia is incompletely understood. Here we report that microglia containing phospho-deficient mutant PS1 display a slower kinetic response to micro injury in the brain in vivo and the inability to degrade Aβ oligomers due to a phagolysosome dysfunction. An Alzheimer's mouse model containing phospho-deficient PS1 show severe Aβ accumulation in microglia as well as the postsynaptic protein PSD95. Our results demonstrate a novel mechanism by which PS1 modulates microglial function and contributes to Alzheimer's -associated phenotypes.
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Affiliation(s)
- Jose Henrique Ledo
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, NY, 10065, USA.
| | - Thomas Liebmann
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, NY, 10065, USA
| | - Ran Zhang
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, 08544, USA
| | - Jerry C Chang
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, NY, 10065, USA
| | - Estefania P Azevedo
- Laboratory of Molecular Genetics, The Rockefeller University, New York, NY, 10065, USA
| | - Eitan Wong
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Hernandez Moura Silva
- Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY, 10016, USA
| | - Olga G Troyanskaya
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, 08544, USA
- Flatiron Institute, Simons Foundation, New York, NY, 10010, USA
| | - Victor Bustos
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, NY, 10065, USA
| | - Paul Greengard
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, NY, 10065, USA
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8
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Shah H, Patel A, Parikh V, Nagani A, Bhimani B, Shah U, Bambharoliya T. The β-Secretase Enzyme BACE1: A Biochemical Enigma for Alzheimer's Disease. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2021; 19:184-194. [PMID: 32452328 DOI: 10.2174/1871527319666200526144141] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 04/18/2020] [Accepted: 04/29/2020] [Indexed: 01/08/2023]
Abstract
Beta site amyloid precursor protein cleaving enzyme 1 (BACE1) is a rational target in Alzheimer's Disease (AD) drug development due to its role in amyloidogenic cleavage of Amyloid Precursor Protein (APP) in generating Amyloid β (Aβ). This β-secretase cleaves not only Amyloid Precursor Protein (APP) and its homologues, but also small series of substrates including neuregulin and β subunit of voltage-gated sodium channel that play a very important role in the development and normal function of the brain. Moreover, BACE1 is modulated at the post-translational level by several factors that are associated with both physiological and pathological functions. Since the discovery of BACE1 over a decade ago, medicinal chemistry and pharmacokinetics of BACE1 small molecule inhibitors have proven challenging for the treatment of Alzheimer's disease.
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Affiliation(s)
- Hirak Shah
- Department of Pharmaceutical Chemistry, Parul Institute of Pharmacy, Parul University, Vadodara, Gujarat 391760, India
| | - Ashish Patel
- Ramanbhai Patel College of Pharmacy, Charotar University of Science and Technology, Changa, Gujarat 388421, India
| | - Vruti Parikh
- Department of Pharmaceutical Chemistry, Parul Institute of Pharmacy, Parul University, Vadodara, Gujarat 391760, India
| | - Afzal Nagani
- Department of Pharmaceutical Chemistry, Parul Institute of Pharmacy, Parul University, Vadodara, Gujarat 391760, India
| | - Bhargav Bhimani
- Piramal Discovery Solution, Pharmaceutical Special Economic Zone, Ahmedabad 382213, India
| | - Umang Shah
- Ramanbhai Patel College of Pharmacy, Charotar University of Science and Technology, Changa, Gujarat 388421, India
| | - Tushar Bambharoliya
- Pharmaceutical Polymer Technology, North Carolina State University, North Carolina, NC, United States
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9
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Yang G, Zhou R, Guo X, Yan C, Lei J, Shi Y. Structural basis of γ-secretase inhibition and modulation by small molecule drugs. Cell 2020; 184:521-533.e14. [PMID: 33373587 DOI: 10.1016/j.cell.2020.11.049] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 10/14/2020] [Accepted: 11/24/2020] [Indexed: 01/01/2023]
Abstract
Development of γ-secretase inhibitors (GSIs) and modulators (GSMs) represents an attractive therapeutic opportunity for Alzheimer's disease (AD) and cancers. However, how these GSIs and GSMs target γ-secretase has remained largely unknown. Here, we report the cryoelectron microscopy (cryo-EM) structures of human γ-secretase bound individually to two GSI clinical candidates, Semagacestat and Avagacestat, a transition state analog GSI L685,458, and a classic GSM E2012, at overall resolutions of 2.6-3.1 Å. Remarkably, each of the GSIs occupies the same general location on presenilin 1 (PS1) that accommodates the β strand from amyloid precursor protein or Notch, interfering with substrate recruitment. L685,458 directly coordinates the two catalytic aspartate residues of PS1. E2012 binds to an allosteric site of γ-secretase on the extracellular side, potentially explaining its modulating activity. Structural analysis reveals a set of shared themes and variations for inhibitor and modulator recognition that will guide development of the next-generation substrate-selective inhibitors.
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Affiliation(s)
- Guanghui Yang
- Beijing Advanced Innovation Center for Structural Biology and Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China; State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Rui Zhou
- Beijing Advanced Innovation Center for Structural Biology and Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xuefei Guo
- Beijing Advanced Innovation Center for Structural Biology and Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Chuangye Yan
- Beijing Advanced Innovation Center for Structural Biology and Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jianlin Lei
- Technology Center for Protein Sciences, Ministry of Education Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yigong Shi
- Beijing Advanced Innovation Center for Structural Biology and Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China; Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Xihu District, Hangzhou 310024, Zhejiang Province, China; Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Xihu District, Hangzhou 310024, Zhejiang Province, China.
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10
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Hur JY, Frost GR, Wu X, Crump C, Pan SJ, Wong E, Barros M, Li T, Nie P, Zhai Y, Wang JC, Tcw J, Guo L, McKenzie A, Ming C, Zhou X, Wang M, Sagi Y, Renton AE, Esposito BT, Kim Y, Sadleir KR, Trinh I, Rissman RA, Vassar R, Zhang B, Johnson DS, Masliah E, Greengard P, Goate A, Li YM. The innate immunity protein IFITM3 modulates γ-secretase in Alzheimer's disease. Nature 2020; 586:735-740. [PMID: 32879487 PMCID: PMC7919141 DOI: 10.1038/s41586-020-2681-2] [Citation(s) in RCA: 234] [Impact Index Per Article: 46.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 05/29/2020] [Indexed: 01/13/2023]
Abstract
Innate immunity is associated with Alzheimer's disease1, but the influence of immune activation on the production of amyloid-β is unknown2,3. Here we identify interferon-induced transmembrane protein 3 (IFITM3) as a γ-secretase modulatory protein, and establish a mechanism by which inflammation affects the generation of amyloid-β. Inflammatory cytokines induce the expression of IFITM3 in neurons and astrocytes, which binds to γ-secretase and upregulates its activity, thereby increasing the production of amyloid-β. The expression of IFITM3 is increased with ageing and in mouse models that express familial Alzheimer's disease genes. Furthermore, knockout of IFITM3 reduces γ-secretase activity and the formation of amyloid plaques in a transgenic mouse model (5xFAD) of early amyloid deposition. IFITM3 protein is upregulated in tissue samples from a subset of patients with late-onset Alzheimer's disease that exhibit higher γ-secretase activity. The amount of IFITM3 in the γ-secretase complex has a strong and positive correlation with γ-secretase activity in samples from patients with late-onset Alzheimer's disease. These findings reveal a mechanism in which γ-secretase is modulated by neuroinflammation via IFITM3 and the risk of Alzheimer's disease is thereby increased.
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Affiliation(s)
- Ji-Yeun Hur
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Georgia R Frost
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Program of Neurosciences, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Xianzhong Wu
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Christina Crump
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Si Jia Pan
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Eitan Wong
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Marilia Barros
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Thomas Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Program of Neurosciences, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Pengju Nie
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA
| | - Yujia Zhai
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jen Chyong Wang
- Ronald M. Loeb Center for Alzheimer's Disease, Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Julia Tcw
- Ronald M. Loeb Center for Alzheimer's Disease, Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Lei Guo
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Andrew McKenzie
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Chen Ming
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Xianxiao Zhou
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Minghui Wang
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yotam Sagi
- Laboratory of Molecular and Cellular Neuroscience, Rockefeller University, New York, NY, USA
| | - Alan E Renton
- Ronald M. Loeb Center for Alzheimer's Disease, Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Bianca T Esposito
- Ronald M. Loeb Center for Alzheimer's Disease, Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yong Kim
- Laboratory of Molecular and Cellular Neuroscience, Rockefeller University, New York, NY, USA
| | | | - Ivy Trinh
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Robert A Rissman
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Robert Vassar
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Eliezer Masliah
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Paul Greengard
- Laboratory of Molecular and Cellular Neuroscience, Rockefeller University, New York, NY, USA
| | - Alison Goate
- Ronald M. Loeb Center for Alzheimer's Disease, Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Genetics and Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Program of Neurosciences, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA.
- Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA.
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11
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Luo W, Ip FCF, Fu G, Cheung K, Tian Y, Hu Y, Sinha A, Cheng EYL, Wu X, Bustos V, Greengard P, Li YM, Sinha SC, Ip NY. A Pentacyclic Triterpene from Ligustrum lucidum Targets γ-Secretase. ACS Chem Neurosci 2020; 11:2827-2835. [PMID: 32786303 PMCID: PMC8325170 DOI: 10.1021/acschemneuro.0c00389] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Amyloid-beta peptides generated by β-secretase- and γ-secretase-mediated successive cleavage of amyloid precursor protein are believed to play a causative role in Alzheimer's disease. Thus, reducing amyloid-beta generation by modulating γ-secretase remains a promising approach for Alzheimer's disease therapeutic development. Here, we screened fruit extracts of Ligustrum lucidum Ait. (Oleaceae) and identified active fractions that increase the C-terminal fragment of amyloid precursor protein and reduce amyloid-beta production in a neuronal cell line. These fractions contain a mixture of two isomeric pentacyclic triterpene natural products, 3-O-cis- or 3-O-trans-p-coumaroyl maslinic acid (OCMA), in different ratios. We further demonstrated that trans-OCMA specifically inhibits γ-secretase and decreases amyloid-beta levels without influencing cleavage of Notch. By using photoactivatable probes targeting the subsites residing in the γ-secretase active site, we demonstrated that trans-OCMA selectively affects the S1 subsite of the active site in this protease. Treatment of Alzheimer's disease transgenic model mice with trans-OCMA or an analogous carbamate derivative of a related pentacyclic triterpene natural product, oleanolic acid, rescued the impairment of synaptic plasticity. This work indicates that the naturally occurring compound trans-OCMA and its analogues could become a promising class of small molecules for Alzheimer's disease treatment.
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Affiliation(s)
- Wenjie Luo
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, New York 10065, United States
| | - Fanny C F Ip
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay Road, Kowloon, Hong Kong, China
- Hong Kong Center for Neurodegenerative Diseases, Hong Kong Science Park, Hong Kong, China
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, Shenzhen-Hong Kong Institute of Brain Science, HKUST Shenzhen Research Institute, Shenzhen, Guangdong, China 518057
| | - Guangmiao Fu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay Road, Kowloon, Hong Kong, China
| | - Kit Cheung
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay Road, Kowloon, Hong Kong, China
| | - Yuan Tian
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, New York 10065, United States
| | - Yueqing Hu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay Road, Kowloon, Hong Kong, China
| | - Anjana Sinha
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, New York 10065, United States
| | - Elaine Y L Cheng
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay Road, Kowloon, Hong Kong, China
| | - Xianzhong Wu
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Victor Bustos
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, New York 10065, United States
| | - Paul Greengard
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, New York 10065, United States
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Subhash C Sinha
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, New York 10065, United States
| | - Nancy Y Ip
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay Road, Kowloon, Hong Kong, China
- Hong Kong Center for Neurodegenerative Diseases, Hong Kong Science Park, Hong Kong, China
- Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, Shenzhen-Hong Kong Institute of Brain Science, HKUST Shenzhen Research Institute, Shenzhen, Guangdong, China 518057
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12
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Substrate recruitment by γ-secretase. Semin Cell Dev Biol 2020; 105:54-63. [DOI: 10.1016/j.semcdb.2020.03.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 03/18/2020] [Accepted: 03/20/2020] [Indexed: 12/27/2022]
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13
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Escamilla-Ayala A, Wouters R, Sannerud R, Annaert W. Contribution of the Presenilins in the cell biology, structure and function of γ-secretase. Semin Cell Dev Biol 2020; 105:12-26. [DOI: 10.1016/j.semcdb.2020.02.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 02/06/2020] [Accepted: 02/17/2020] [Indexed: 01/25/2023]
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14
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Barros M, Houlihan WJ, Paresi CJ, Brendel M, Rynearson KD, Lee CW, Prikhodko O, Cregger C, Chang G, Wagner SL, Gilchrist ML, Li YM. γ-Secretase Partitioning into Lipid Bilayers Remodels Membrane Microdomains after Direct Insertion. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:6569-6579. [PMID: 32432881 PMCID: PMC7887708 DOI: 10.1021/acs.langmuir.0c01178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
γ-Secretase is a multisubunit complex that catalyzes intramembranous cleavage of transmembrane proteins. The lipid environment forms membrane microdomains that serve as spatio-temporal platforms for proteins to function properly. Despite substantial advances in the regulation of γ-secretase, the effect of the local membrane lipid microenvironment on the regulation of γ-secretase is poorly understood. Here, we characterized and quantified the partitioning of γ-secretase and its substrates, the amyloid precursor protein (APP) and Notch, into lipid bilayers using solid-supported model membranes. Notch substrate is preferentially localized in the liquid-disordered (Ld) lipid domains, whereas APP and γ-secretase partition as single or higher complex in both phases but highly favor the ordered phase, especially after recruiting lipids from the ordered phase, indicating that the activity and specificity of γ-secretase against these two substrates are modulated by membrane lateral organization. Moreover, time-elapse measurements reveal that γ-secretase can recruit specific membrane components from the cholesterol-rich Lo phase and thus creates a favorable lipid environment for substrate recognition and therefore activity. This work offers insight into how γ-secretase and lipid modulate each other and control its activity and specificity.
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Affiliation(s)
- Marilia Barros
- Chemical Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, United States
| | - William J Houlihan
- Department of Chemical Engineering and the Department of Biomedical Engineering, The City College of the City University of New York, New York, New York 10031, United States
| | - Chelsea J Paresi
- Chemical Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, United States
- Pharmacology Graduate Program, Weill Graduate School of Medical Sciences of Cornell University, New York, New York 10021, United States
| | - Matthew Brendel
- Molecular Cytology Core, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, United States
| | - Kevin D Rynearson
- Department of Neurosciences, University of California, San Diego, California 92093, United States
| | | | - Olga Prikhodko
- Department of Neurosciences, University of California, San Diego, California 92093, United States
| | - Cristina Cregger
- Department of Neurosciences, University of California, San Diego, California 92093, United States
| | | | - Steven L Wagner
- Department of Neurosciences, University of California, San Diego, California 92093, United States
- Research Biologist, VA San Diego Healthcare System, La Jolla, California 92161, United States
| | - M Lane Gilchrist
- Department of Chemical Engineering and the Department of Biomedical Engineering, The City College of the City University of New York, New York, New York 10031, United States
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, United States
- Pharmacology Graduate Program, Weill Graduate School of Medical Sciences of Cornell University, New York, New York 10021, United States
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15
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Chávez-Gutiérrez L, Szaruga M. Mechanisms of neurodegeneration - Insights from familial Alzheimer's disease. Semin Cell Dev Biol 2020; 105:75-85. [PMID: 32418657 DOI: 10.1016/j.semcdb.2020.03.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 03/13/2020] [Accepted: 03/16/2020] [Indexed: 12/18/2022]
Abstract
The rising prevalence of Alzheimer's disease (AD), together with the lack of effective treatments, portray it as one of the major health challenges of our times. Untangling AD implies advancing the knowledge of the biology that gets disrupted during the disease while deciphering the molecular and cellular mechanisms leading to AD-related neurodegeneration. In fact, a solid mechanistic understanding of the disease processes stands as an essential prerequisite for the development of safe and effective treatments. Genetics has provided invaluable clues to the genesis of the disease by revealing deterministic genes - Presenilins (PSENs) and the Amyloid Precursor Protein (APP) - that, when affected, lead in an autosomal dominant manner to early-onset, familial AD (FAD). PSEN is the catalytic subunit of the membrane-embedded γ-secretase complexes, which act as proteolytic switches regulating key cell signalling cascades. Importantly, these intramembrane proteases are responsible for the production of Amyloid β (Aβ) peptides from APP. The convergence of pathogenic mutations on one functional pathway, the amyloidogenic cleavage of APP, strongly supports the significance of this process in AD pathogenesis. Here, we review and discuss the state-of-the-art knowledge of the molecular mechanisms underlying FAD, their implications for the sporadic form of the disease and for the development of safe AD therapeutics.
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Affiliation(s)
- Lucía Chávez-Gutiérrez
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium; Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), KU Leuven, Leuven, Belgium.
| | - Maria Szaruga
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium; Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), KU Leuven, Leuven, Belgium
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16
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Nie P, Vartak A, Li YM. γ-Secretase inhibitors and modulators: Mechanistic insights into the function and regulation of γ-Secretase. Semin Cell Dev Biol 2020; 105:43-53. [PMID: 32249070 DOI: 10.1016/j.semcdb.2020.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 03/10/2020] [Accepted: 03/11/2020] [Indexed: 02/08/2023]
Abstract
Over two decades, γ-secretase has been the target for extensive therapeutic development due to its pivotal role in pathogenesis of Alzheimer's disease and cancer. However, it has proven to be a challenging task owing to its large set of substrates and our limited understanding of the enzyme's structural and mechanistic features. The scientific community is taking bigger strides towards solving this puzzle with recent advancement in techniques like cryogenic electron microscopy (cryo-EM) and photo-affinity labelling (PAL). This review highlights the significance of the PAL technique with multiple examples of photo-probes developed from γ-secretase inhibitors and modulators. The binding of these probes into active and/or allosteric sites of the enzyme has provided crucial information on the γ-secretase complex and improved our mechanistic understanding of this protease. Combining the knowledge of function and regulation of γ-secretase will be a decisive factor in developing novel γ-secretase modulators and biological therapeutics.
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Affiliation(s)
- Pengju Nie
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Pharmacology program, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Abhishek Vartak
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Pharmacology program, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA.
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17
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Liu H, Mei FC, Yang W, Wang H, Wong E, Cai J, Toth E, Luo P, Li YM, Zhang W, Cheng X. Epac1 inhibition ameliorates pathological angiogenesis through coordinated activation of Notch and suppression of VEGF signaling. SCIENCE ADVANCES 2020; 6:eaay3566. [PMID: 31911948 PMCID: PMC6938696 DOI: 10.1126/sciadv.aay3566] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 10/29/2019] [Indexed: 05/26/2023]
Abstract
In this study, we investigated the roles of Epac1 in pathological angiogenesis and its potential as a novel therapeutic target for the treatment of vasoproliferative diseases. Genetic deletion of Epac1 ameliorated pathological angiogenesis in mouse models of oxygen-induced retinopathy (OIR) and carotid artery ligation. Moreover, genetic deletion or pharmacological inhibition of Epac1 suppressed microvessel sprouting from ex vivo aortic ring explants. Mechanistic studies revealed that Epac1 acted as a previously unidentified inhibitor of the γ-secretase/Notch signaling pathway via interacting with γ-secretase and regulating its intracellular trafficking while enhancing vascular endothelial growth factor signaling to promote pathological angiogenesis. Pharmacological administration of an Epac-specific inhibitor suppressed OIR-induced neovascularization in wild-type mice, recapitulating the phenotype of genetic Epac1 knockout. Our results demonstrate that Epac1 signaling is critical for the progression of pathological angiogenesis but not for physiological angiogenesis and that the newly developed Epac-specific inhibitors are effective in combating proliferative retinopathy.
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Affiliation(s)
- Hua Liu
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA
| | - Fang C. Mei
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX, USA
- Texas Therapeutics Institute, University of Texas Health Science Center, Houston, TX, USA
| | - Wenli Yang
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX, USA
- Texas Therapeutics Institute, University of Texas Health Science Center, Houston, TX, USA
| | - Hui Wang
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX, USA
- Texas Therapeutics Institute, University of Texas Health Science Center, Houston, TX, USA
| | - Eitan Wong
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jingjing Cai
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA
| | - Emma Toth
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX, USA
- Texas Therapeutics Institute, University of Texas Health Science Center, Houston, TX, USA
| | - Pei Luo
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX, USA
- Texas Therapeutics Institute, University of Texas Health Science Center, Houston, TX, USA
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Wenbo Zhang
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA
- Department of Neuroscience, Cell Biology and Anatomy, University of Texas Medical Branch, Galveston, TX, USA
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX, USA
- Texas Therapeutics Institute, University of Texas Health Science Center, Houston, TX, USA
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18
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Walck AJ, Harkins KR. Modification of AlphaLISA Excitation Wavelength Leads to Improved Assay Sensitivity for Photosynthetic Tissue Samples. SLAS Technol 2019; 24:429-436. [DOI: 10.1177/2472630318821338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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19
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Yusof HH, Lee HC, Seth EA, Wu X, Hewitt CA, Scott HS, Cheah PS, Li YM, Chau DM, Ling KH. Expression Profiling of Notch Signalling Pathway and Gamma-Secretase Activity in the Brain of Ts1Cje Mouse Model of Down Syndrome. J Mol Neurosci 2019; 67:632-642. [PMID: 30758748 PMCID: PMC8824580 DOI: 10.1007/s12031-019-01275-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 02/05/2019] [Indexed: 01/23/2023]
Abstract
Notch signalling pathway is involved in the proliferation of neural progenitor cells (NPCs), to inhibit neuronal cell commitment and to promote glial cell fate. Notch protein is cleaved by gamma-secretase, a multisubunit transmembrane protein complex that releases the Notch intracellular domain (NICD) and subsequently activates the downstream targets. Down syndrome (DS) individuals exhibit an increased number of glial cells (particularly astrocytes), and reduced number of neurons suggesting the involvement of Notch signalling pathway in the neurogenic-to-gliogenic shift in DS brain. Ts1Cje is a DS mouse model that exhibit similar neuropathology to human DS individuals. To date, the spatiotemporal gene expression of the Notch and gamma-secretase genes have not been characterised in Ts1Cje mouse brain. Understanding the expression pattern of Notch and gamma-secretase genes may provide a better understanding of the underlying mechanism that leads to the shift. Gene expression analysis using RT-qPCR was performed on early embryonic and postnatal development of DS brain. In the developing mouse brain, mRNA expression analysis showed that gamma-secretase members (Psen1, Pen-2, Aph-1b, and Ncstn) were not differentially expressed. Notch2 was found to be downregulated in the developing Ts1Cje brain samples. Postnatal gene expression study showed complex expression patterns and Notch1 and Notch2 genes were found to be significantly downregulated in the hippocampus at postnatal day 30. Results from RT-qPCR analysis from E15.5 neurosphere culture showed an increase of expression of Psen1, and Aph-1b but downregulation of Pen-2 and Ncstn genes. Gamma-secretase activity in Ts1Cje E15.5 neurospheres was significantly increased by fivefold. In summary, the association and the role of Notch and gamma-secretase gene expression throughout development with neurogenic-to-gliogenic shift in Ts1Cje remain undefined and warrant further validation.
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Affiliation(s)
- Hadri Hadi Yusof
- Genetics & Regenerative Medicine Research Centre (GRMRC), Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Han-Chung Lee
- Genetics & Regenerative Medicine Research Centre (GRMRC), Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Eryse Amira Seth
- Genetics & Regenerative Medicine Research Centre (GRMRC), Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Xiangzhong Wu
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Chelsee A Hewitt
- Department of Pathology, The Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Hamish S Scott
- Department of Genetics and Molecular Pathology, Centre for Cancer Biology, An Alliance Between SA Pathology and the University of South Australia, SA Pathology, Adelaide, Australia
- School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, SA, Australia
- School of Pharmacy and Medical Science, University of South Australia, Adelaide, Australia
- School of Biological Sciences, University of Adelaide, Adelaide, Australia
- Australian Cancer Research Foundation Genomics Facility, Centre for Cancer Biology, SA Pathology, Adelaide, Australia
| | - Pike-See Cheah
- Genetics & Regenerative Medicine Research Centre (GRMRC), Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - De-Ming Chau
- Genetics & Regenerative Medicine Research Centre (GRMRC), Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - King-Hwa Ling
- Genetics & Regenerative Medicine Research Centre (GRMRC), Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.
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20
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Abstract
γ-Secretase cleaves multiple transmembrane proteins, but little is known about how it controls its substrate specificity. γ-Secretase activating protein (GSAP) has been reported to differentially activate γ-secretase for APP and Notch cleavages. The mechanism by which GSAP regulates γ-secretase specificity is elusive. Here, we demonstrate that GSAP directly regulates γ-secretase activity and specificity. Furthermore, GSAP functions as a switch between two forms of γ-secretase that have different activities for APP and Notch substrates, leading to different specificities. These findings open a new avenue for drug development through targeting the specificity of modifying proteins. This work also suggests that the association of GSAP with aging, Alzheimer’s disease, and Down syndrome could be attributed to the function of GSAP in the regulation of γ-secretase. The mechanism by which γ-secretase activating protein (GSAP) regulates γ-secretase activity has not yet been elucidated. Here, we show that knockout of GSAP in cultured cells directly reduces γ-secretase activity for Aβ production, but not for Notch1 cleavage, suggesting that GSAP may induce a conformational change contributing to the specificity of γ-secretase. Furthermore, using an active-site–directed photoprobe with double cross-linking moieties, we demonstrate that GSAP modifies the orientation and/or distance of the PS1 N-terminal fragment and the PS1 C-terminal fragment, a region containing the active site of γ-secretase. This work offers insight into how GSAP regulates γ-secretase specificity.
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Abstract
Alzheimer's disease (AD), the most common cause of age-dependent dementia, is one of the most significant healthcare problems worldwide. Aggravating this situation, drugs that are currently US Food and Drug Administration (FDA)-approved for AD treatment do not prevent or delay disease progression. Therefore, developing effective therapies for AD patients is of critical urgency. Human genetic and clinical studies over the past three decades have indicated that abnormal generation or accumulation of amyloid-β (Aβ) peptides is a likely culprit in AD pathogenesis. Aβ is generated from amyloid precursor protein (APP) via proteolytic cleavage by β-site APP cleaving enzyme 1 (BACE1) (memapsin 2, β-secretase, Asp 2 protease) and γ-secretase. Mice deficient in BACE1 show abrogated production of Aβ. Therefore, pharmacological inhibition of BACE1 is being intensively pursued as a therapeutic approach to treat AD patients. Recent setbacks in clinical trials with BACE1 inhibitors have highlighted the critical importance of understanding how to properly inhibit BACE1 to treat AD patients. This review summarizes the recent studies on the role of BACE1 in synaptic functions as well as our views on BACE1 inhibition as an effective AD treatment.
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Affiliation(s)
- Brati Das
- Department of Neuroscience, Room E4032, UConn Health, 263 Farmington Avenue, Farmington, CT, 06030-3401, USA
| | - Riqiang Yan
- Department of Neuroscience, Room E4032, UConn Health, 263 Farmington Avenue, Farmington, CT, 06030-3401, USA.
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Stoychev KR, Stoimenova-Popova M, Chumpalova P, Ilieva L, Swamad M, Kamburova-Martinova Z. A Clinical Case of Patient Carrying Rare Pathological PSEN1 Gene Mutation (L424V) Demonstrates the Phenotypic Heterogenity of Early Onset Familial AD. Front Psychiatry 2019; 10:857. [PMID: 31920735 PMCID: PMC6918796 DOI: 10.3389/fpsyt.2019.00857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 10/31/2019] [Indexed: 12/22/2022] Open
Abstract
Dementia comprises several neurodegenerative disorders with similar neuropsychiatric features and Alzheimer's disease (AD) is the most common of them. Genetic factors are strongly implicated into its etiology especially for early-onset cases (EOAD) occuring before the age of 65. About 10% of these are inherited in autosomal dominant fashion via pathogenic polymorphisms in three genes- APP, PSEN-1, and PSEN-2. Despite genotypic clarity, however, phenotypic variability exists with different symptom constellations observed in patients with identical mutations. Below, we present a case of a 39-year-old male with a family history for early onset dementia who was referred to our department with anamnesis for abrupt behavioral change 7 months prior to hospitalization-noticeable slowing of speech and reactivity, impaired occupational functioning and irritability, followed by aphasic symptoms and transient episodes of disorientation. He was followed up for 2 years and manifested rapidly progressing cognitive decline with further deterioration of speech, apraxia, acalculia, ataxia, and subsequently bradykinesia and tremor. Based on the clinical and neuroimaging findings (severe cortical atrophy), familial EOAD was suspected and a whole exome sequence (WES) analysis was performed. It identified a heterozygous missense variant Leu424Val (g.71074C > G) in PSEN-1 gene considered to be pathogenic, and only reported once until now in a Spanish patient in 2009. Despite genotype identity however, distinct phenotypic presentations were observed in the two affected subjects, with different neuroimaging findings, and the presence and absence of seizures in the Spanish and Bulgarian case, respectively. Besides, myoclonus and spastic paraparesis considered "typical" EOAD clinical features were absent. Age of symptom onset was consistent with two of the reported mutations affecting 424 codon of PSEN-1 gene and significantly earlier than the other two implying that factors influencing activity of PSEN-1 pathological forms are yet to be clarified. Furthermore, our patient had co-occurring lupus erythematosus (LE) and we suggest that this condition might be etiologically linked to the PSEN-1 mutation. In addition to illustrating the symptomatic heterogeneity of PSEN-1 caused EOAD, our study confirms that in patients presenting with early cognitive deterioration and family history for dementia, WES can be especially informative and should be considered as a first-line examination.
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Affiliation(s)
| | | | | | - Lilia Ilieva
- Department of Neurology, Sveti Panteleimon Hospital, Pleven, Bulgaria
| | - Mohamed Swamad
- Department of Health and Aging Unit, King's College Hospital, London, United Kingdom
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23
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Steiner H, Fukumori A, Tagami S, Okochi M. Making the final cut: pathogenic amyloid-β peptide generation by γ-secretase. Cell Stress 2018; 2:292-310. [PMID: 31225454 PMCID: PMC6551803 DOI: 10.15698/cst2018.11.162] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Alzheimer´s disease (AD) is a devastating neurodegenerative disease of the elderly population. Genetic evidence strongly suggests that aberrant generation and/or clearance of the neurotoxic amyloid-β peptide (Aβ) is triggering the disease. Aβ is generated from the amyloid precursor protein (APP) by the sequential cleavages of β- and γ-secretase. The latter cleavage by γ-secretase, a unique and fascinating four-component protease complex, occurs in the APP transmembrane domain thereby releasing Aβ species of 37-43 amino acids in length including the longer, highly pathogenic peptides Aβ42 and Aβ43. The lack of a precise understanding of Aβ generation as well as of the functions of other γ-secretase substrates has been one factor underlying the disappointing failure of γ-secretase inhibitors in clinical trials, but on the other side also been a major driving force for structural and in depth mechanistic studies on this key AD drug target in the past few years. Here we review recent breakthroughs in our understanding of how the γ-secretase complex recognizes substrates, of how it binds and processes β-secretase cleaved APP into different Aβ species, as well as the progress made on a question of outstanding interest, namely how clinical AD mutations in the catalytic subunit presenilin and the γ-secretase cleavage region of APP lead to relative increases of Aβ42/43. Finally, we discuss how the knowledge emerging from these studies could be used to therapeutically target this enzyme in a safe way.
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Affiliation(s)
- Harald Steiner
- Biomedical Center (BMC), Metabolic Biochemistry, Ludwig-Maximilians-University Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Akio Fukumori
- Department of Aging Neurobiology, National Center for Geriatrics and Gerontology, Obu & Department of Mental Health Promotion, Osaka University Graduate School of Medicine, Toyonaka, Japan
| | - Shinji Tagami
- Neuropsychiatry, Department of Integrated Medicine, Division of Internal Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Masayasu Okochi
- Neuropsychiatry, Department of Integrated Medicine, Division of Internal Medicine, Osaka University Graduate School of Medicine, Suita, Japan
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24
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Johnson DS, Li YM, Pettersson M, St George-Hyslop PH. Structural and Chemical Biology of Presenilin Complexes. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a024067. [PMID: 28320827 PMCID: PMC5710098 DOI: 10.1101/cshperspect.a024067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The presenilin proteins are the catalytic subunits of a tetrameric complex containing presenilin 1 or 2, anterior pharynx defective 1 (APH1), nicastrin, and PEN-2. Other components such as TMP21 may exist in a subset of specialized complexes. The presenilin complex is the founding member of a unique class of aspartyl proteases that catalyze the γ, ɛ, ζ site cleavage of the transmembrane domains of Type I membrane proteins including amyloid precursor protein (APP) and Notch. Here, we detail the structural and chemical biology of this unusual enzyme. Taken together, these studies suggest that the complex exists in several conformations, and subtle long-range (allosteric) shifts in the conformation of the complex underpin substrate access to the catalytic site and the mechanism of action for allosteric inhibitors and modulators. Understanding the mechanics of these shifts will facilitate the design of γ-secretase modulator (GSM) compounds that modulate the relative efficiency of γ, ɛ, ζ site cleavage and/or substrate specificity.
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Affiliation(s)
- Douglas S. Johnson
- Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065
| | - Martin Pettersson
- Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139
| | - Peter H. St George-Hyslop
- Cambridge Institute for Medical Research, Wellcome Trust MRC Building, Addenbrookes Hospital, Cambridge CB2 0XY, United Kingdom,Tanz Centre for Research in Neurodegenerative Diseases and Departments of Medicine, Laboratory Medicine and Pathobiology, and Medical Biophysics, University of Toronto, Toronto, Ontario M5T 2S8, Canada
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25
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Zhu B, Jiang L, Huang T, Zhao Y, Liu T, Zhong Y, Li X, Campos A, Pomeroy K, Masliah E, Zhang D, Xu H. ER-associated degradation regulates Alzheimer's amyloid pathology and memory function by modulating γ-secretase activity. Nat Commun 2017; 8:1472. [PMID: 29133892 PMCID: PMC5684335 DOI: 10.1038/s41467-017-01799-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 10/13/2017] [Indexed: 12/11/2022] Open
Abstract
Endoplasmic-reticulum-associated degradation (ERAD) is an important protein quality control system which maintains protein homeostasis. Constituents of the ERAD complex and its role in neurodegeneration are not yet fully understood. Here, using proteomic and FRET analyses, we demonstrate that the ER protein membralin is an ERAD component, which mediates degradation of ER luminal and membrane substrates. Interestingly, we identify nicastrin, a key component of the γ-secretase complex, as a membralin binding protein and membralin-associated ERAD substrate. We demonstrate a reduction of membralin mRNA and protein levels in Alzheimer's disease (AD) brain, the latter of which inversely correlates with nicastrin abundance. Furthermore, membralin deficiency enhances γ-secretase activity and neuronal degeneration. In a mouse AD model, downregulating membralin results in β-amyloid pathology, neuronal death, and exacerbates synaptic/memory deficits. Our results identify membralin as an ERAD component and demonstrate a critical role for ERAD in AD pathogenesis.
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Affiliation(s)
- Bing Zhu
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - LuLin Jiang
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Timothy Huang
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Yingjun Zhao
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Tongfei Liu
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Yongwang Zhong
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Xiaoguang Li
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Alexandre Campos
- Proteomics Facility, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Kenneth Pomeroy
- Proteomics Facility, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Eliezer Masliah
- Departments of Neurosciences and Pathology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Dongxian Zhang
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Huaxi Xu
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA.
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, 361005, Fujian, China.
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26
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Abstract
Alzheimer's disease (AD) is characterized by accumulation of the β-amyloid peptide (Aβ), which is generated through sequential proteolysis of the amyloid precursor protein (APP), first by the action of β-secretase, generating the β-C-terminal fragment (βCTF), and then by the Presenilin 1 (PS1) enzyme in the γ-secretase complex, generating Aβ. γ-Secretase is an intramembranous protein complex composed of Aph1, Pen2, Nicastrin, and Presenilin 1. Although it has a central role in the pathogenesis of AD, knowledge of the mechanisms that regulate PS1 function is limited. Here, we show that phosphorylation of PS1 at Ser367 does not affect γ-secretase activity, but has a dramatic effect on Aβ levels in vivo. We identified CK1γ2 as the endogenous kinase responsible for the phosphorylation of PS1 at Ser367. Inhibition of CK1γ leads to a decrease in PS1 Ser367 phosphorylation and an increase in Aβ levels in cultured cells. Transgenic mice in which Ser367 of PS1 was mutated to Ala, show dramatic increases in Aβ peptide and in βCTF levels in vivo. Finally, we show that this mutation impairs the autophagic degradation of βCTF, resulting in its accumulation and increased levels of Aβ peptide and plaque load in the brain. Our results demonstrate that PS1 regulates Aβ levels by a unique bifunctional mechanism. In addition to its known role as the catalytic subunit of the γ-secretase complex, selective phosphorylation of PS1 on Ser367 also decreases Aβ levels by increasing βCTF degradation through autophagy. Elucidation of the mechanism by which PS1 regulates βCTF degradation may aid in the development of potential therapies for Alzheimer's disease.
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27
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Mamelak M. Energy and the Alzheimer brain. Neurosci Biobehav Rev 2017; 75:297-313. [PMID: 28193453 DOI: 10.1016/j.neubiorev.2017.02.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 01/30/2017] [Accepted: 02/01/2017] [Indexed: 01/01/2023]
Abstract
The high energy demands of the poorly myelinated long axon hippocampal and cortical neurons render these neurons selectively vulnerable to degeneration in Alzheimer's disease. However, pathology engages all of the major elements of the neurovascular unit of the mature Alzheimer brain, the neurons, glia and blood vessels. Neurons present with retrograde degeneration of the axodendritic tree, capillaries with string vessels and markedly reduced densities and glia with signs of inflammatory activation. The neurons, capillaries and astrocytes of the mature Alzheimer brain harbor structurally defective mitochondria. Clinically, reduced glucose utilization, decades before cognitive deterioration, betrays ongoing energy insufficiency. β-hydroxybutyrate and γ-hydroxybutyrate can both provide energy to the brain when glucose utilization is blocked. Early work in mouse models of Alzheimer's disease demonstrate their ability to reverse the pathological changes in the Alzheimer brain and initial clinical trials reveal their ability to improve cognition and every day function. Supplying the brain with energy holds great promise for delaying the onset of Alzheimer's disease and slowing its progress.
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28
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γ-Secretase Modulators as Aβ42-Lowering Pharmacological Agents to Treat Alzheimer’s Disease. TOPICS IN MEDICINAL CHEMISTRY 2017. [DOI: 10.1007/7355_2016_19] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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29
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Fernandez MA, Biette KM, Dolios G, Seth D, Wang R, Wolfe MS. Transmembrane Substrate Determinants for γ-Secretase Processing of APP CTFβ. Biochemistry 2016; 55:5675-5688. [PMID: 27649271 DOI: 10.1021/acs.biochem.6b00718] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The amyloid β-peptide (Aβ) of Alzheimer's disease (AD) is generated by proteolysis within the transmembrane domain (TMD) of a C-terminal fragment of the amyloid β protein-precursor (APP CTFβ) by the γ-secretase complex. This processing produces Aβ ranging from 38 to 49 residues in length. Evidence suggests that this spectrum of Aβ peptides is the result of successive γ-secretase cleavages, with endoproteolysis first occurring at the ε sites to generate Aβ48 or Aβ49, followed by C-terminal trimming mostly every three residues along two product lines to generate shorter, secreted forms of Aβ: the primary Aβ49-46-43-40 line and a minor Aβ48-45-42-38 line. The major secreted Aβ species are Aβ40 and Aβ42, and an increased proportion of the longer, aggregation-prone Aβ42 compared to Aβ40 is widely thought to be important in AD pathogenesis. We examined TMD substrate determinants of the specificity and efficiency of ε site endoproteolysis and carboxypeptidase trimming of CTFβ by γ-secretase. We determined that the C-terminal negative charge of the intermediate Aβ49 does not play a role in its trimming by γ-secretase. Peptidomimetic probes suggest that γ-secretase has S1', S2', and S3' pockets, through which trimming by tripeptides may be determined. However, deletion of residues around the ε sites demonstrates that a depth of three residues within the TMD is not a determinant of the location of endoproteolytic ε cleavage of CTFβ. We also show that instability of the CTFβ TMD helix near the ε site significantly increases endoproteolysis, and that helical instability near the carboxypeptidase cleavage sites facilitates C-terminal trimming by γ-secretase. In addition, we found that CTFβ dimers are not endoproteolyzed by γ-secretase. These results support a model in which initial interaction of the array of residues along the undimerized single helical TMD of substrates dictates the site of initial ε cleavage and that helix unwinding is essential for both endoproteolysis and carboxypeptidase trimming.
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Affiliation(s)
- Marty A Fernandez
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts 02115, United States
| | - Kelly M Biette
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts 02115, United States
| | - Georgia Dolios
- Icahn School of Medicine at Mount Sinai , New York, New York 10029, United States
| | - Divya Seth
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts 02115, United States
| | - Rong Wang
- Icahn School of Medicine at Mount Sinai , New York, New York 10029, United States
| | - Michael S Wolfe
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts 02115, United States
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30
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Crump CJ, Murrey HE, Ballard TE, am Ende CW, Wu X, Gertsik N, Johnson DS, Li YM. Development of Sulfonamide Photoaffinity Inhibitors for Probing Cellular γ-Secretase. ACS Chem Neurosci 2016; 7:1166-73. [PMID: 27253220 DOI: 10.1021/acschemneuro.6b00127] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
γ-Secretase is a multiprotein complex that catalyzes intramembrane proteolysis associated with Alzheimer's disease and cancer. Here, we have developed potent sulfonamide clickable photoaffinity probes that target γ-secretase in vitro and in cells by incorporating various photoreactive groups and walking the clickable alkyne handle to different positions around the molecule. We found that benzophenone is preferred over diazirine as a photoreactive group within the sulfonamide scaffold for labeling γ-secretase. Intriguingly, the placement of the alkyne at different positions has little effect on probe potency but has a significant impact on the efficiency of labeling of γ-secretase. Moreover, the optimized clickable photoprobe, 163-BP3, was utilized as a cellular probe to effectively assess the target engagement of inhibitors with γ-secretase in primary neuronal cells. In addition, biotinylated 163-BP3 probes were developed and used to capture the native γ-secretase complex in the 3-[(3-cholamidopropyl)dimethylammonio]-2-hydroxy-1-propanesulfonate (CHAPSO) solubilized state. Taken together, these next generation clickable and biotinylated sulfonamide probes offer new tools to study γ-secretase in biochemical and cellular systems. Finally, the data provide insights into structural features of the sulfonamide inhibitor binding site in relation to the active site and into the design of clickable photoaffinity probes.
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Affiliation(s)
- Christina J. Crump
- Chemical
Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York
Avenue, New York, New York 10065, United States
| | - Heather E. Murrey
- Pfizer Worldwide Research and Development, Worldwide Medicinal Chemistry, Cambridge, Massachusetts 02139, United States
| | - T. Eric Ballard
- Pfizer Worldwide Research and Development, Worldwide
Medicinal Chemistry Groton, Connecticut 06340, United States
| | - Christopher W. am Ende
- Pfizer Worldwide Research and Development, Worldwide
Medicinal Chemistry Groton, Connecticut 06340, United States
| | - Xianzhong Wu
- Chemical
Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York
Avenue, New York, New York 10065, United States
| | - Natalya Gertsik
- Chemical
Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York
Avenue, New York, New York 10065, United States
| | - Douglas S. Johnson
- Pfizer Worldwide Research and Development, Worldwide Medicinal Chemistry, Cambridge, Massachusetts 02139, United States
| | - Yue-Ming Li
- Chemical
Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York
Avenue, New York, New York 10065, United States
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31
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Fukumori A, Steiner H. Substrate recruitment of γ-secretase and mechanism of clinical presenilin mutations revealed by photoaffinity mapping. EMBO J 2016; 35:1628-43. [PMID: 27220847 DOI: 10.15252/embj.201694151] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 04/26/2016] [Indexed: 12/27/2022] Open
Abstract
Intramembrane proteases execute fundamental biological processes ranging from crucial signaling events to general membrane proteostasis. Despite the availability of structural information on these proteases, it remains unclear how these enzymes bind and recruit substrates, particularly for the Alzheimer's disease-associated γ-secretase. Systematically scanning amyloid precursor protein substrates containing a genetically inserted photocrosslinkable amino acid for binding to γ-secretase allowed us to identify residues contacting the protease. These were primarily found in the transmembrane cleavage domain of the substrate and were also present in the extramembranous domains. The N-terminal fragment of the catalytic subunit presenilin was determined as principal substrate-binding site. Clinical presenilin mutations altered substrate binding in the active site region, implying a pathogenic mechanism for familial Alzheimer's disease. Remarkably, PEN-2 was identified besides nicastrin as additional substrate-binding subunit. Probing proteolysis of crosslinked substrates revealed a mechanistic model of how these subunits interact to mediate a stepwise transfer of bound substrate to the catalytic site. We propose that sequential binding steps might be common for intramembrane proteases to sample and select cognate substrates for catalysis.
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Affiliation(s)
- Akio Fukumori
- Biomedical Center (BMC), Metabolic Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Harald Steiner
- Biomedical Center (BMC), Metabolic Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
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32
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Zhang X, Sullivan E, Scimeca M, Wu X, Li YM, Sisodia SS. Evidence That the "Lid" Domain of Nicastrin Is Not Essential for Regulating γ-Secretase Activity. J Biol Chem 2016; 291:6748-53. [PMID: 26887941 DOI: 10.1074/jbc.c115.701649] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Indexed: 11/06/2022] Open
Abstract
Understanding of the structure of the γ-secretase complex consisting of presenilin (PS), anterior pharynx-defective 1 (APH-1), nicastrin (NCT), and presenilin enhancer 2 (PEN-2) is of significant therapeutic interest for the design of γ-secretase modulators for Alzheimer disease. The structure of γ-secretase revealed by cryo-EM approaches suggested a substrate binding mechanism for NCT, a bilobar structure that involved rotation of the two lobes around a central pivot and opening of a "lid" region that facilitates substrate recruitment. To validate this proposal, we expressed NCT that lacks the lid entirely, or a variety of NCT variants that harbor mutations at highly conserved residues in the lid region inNCT-deficient cells, and then assessed their impact on γ-secretase assembly, activity, and stability. In addition, we assessed the impact of mutating a critical residue proposed to be a pivot around which the two lobes of NCT rotate. Our results show that neither the mutations on the lid tested here nor the entire lid deletion has any significant impact on γ-secretase assembly, activity, and stability, and that NCT with the mutation of the proposed pivot rescues γ-secretase activity inNCT-deficient cells in a manner indistinguishable from WT NCT. These findings indicate that the NCT lid is not an essential element necessary for γ-secretase assembly, activity, and stability, and that rotation of the two lobes appears not to be a prerequisite for substrate binding and γ-secretase function.
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Affiliation(s)
- Xulun Zhang
- From the Department of Neurobiology, The University of Chicago, Chicago, Illinois 60637 and
| | - Eric Sullivan
- From the Department of Neurobiology, The University of Chicago, Chicago, Illinois 60637 and
| | - Maggie Scimeca
- From the Department of Neurobiology, The University of Chicago, Chicago, Illinois 60637 and
| | - Xianzhong Wu
- the Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065
| | - Yue-Ming Li
- the Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065
| | - Sangram S Sisodia
- From the Department of Neurobiology, The University of Chicago, Chicago, Illinois 60637 and
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33
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Gertsik N, Chau DM, Li YM. γ-Secretase Inhibitors and Modulators Induce Distinct Conformational Changes in the Active Sites of γ-Secretase and Signal Peptide Peptidase. ACS Chem Biol 2015; 10:1925-31. [PMID: 26030233 DOI: 10.1021/acschembio.5b00321] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
γ-Secretase inhibitors (GSIs) and modulators (GSMs) are at the frontline of cancer and Alzheimer's disease research, respectively. While both are therapeutically promising, not much is known about their interactions with proteins other than γ-secretase. Signal peptide peptidase (SPP), like γ-secretase, is a multispan transmembrane aspartyl protease that catalyzes regulated intramembrane proteolysis. We used active site-directed photophore walking probes to study the effects of different GSIs and GSMs on the active sites of γ-secretase and SPP and found that nontransition state GSIs inhibit labeling of γ-secretase by activity-based probes but enhance labeling of SPP. The opposite is true of GSMs, which have little effect on the labeling of γ-secretase but diminish labeling of SPP. These results demonstrate that GSIs and GSMs are altering the structure of not only γ-secretase but also SPP, leading to potential changes in enzyme activity and specificity that may impact the clinical outcomes of these molecules.
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Affiliation(s)
- Natalya Gertsik
- Molecular
Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - De-Ming Chau
- Molecular
Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
- Clinical
Genetics Unit Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, Malaysia
| | - Yue-Ming Li
- Molecular
Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
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34
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Cleavage of amyloid precursor protein by an archaeal presenilin homologue PSH. Proc Natl Acad Sci U S A 2015; 112:3344-9. [PMID: 25733893 DOI: 10.1073/pnas.1502150112] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Aberrant cleavage of amyloid precursor protein (APP) by γ-secretase contributes to the development of Alzheimer's disease. More than 200 disease-derived mutations have been identified in presenilin (the catalytic subunit of γ-secretase), making modulation of γ-secretase activity a potentially attractive therapeutic opportunity. Unfortunately, the technical challenges in dealing with intact γ-secretase have hindered discovery of modulators and demand a convenient substitute approach. Here we report that, similar to γ-secretase, the archaeal presenilin homolog PSH faithfully processes the substrate APP C99 into Aβ42, Aβ40, and Aβ38. The molar ratio of the cleavage products Aβ42 over Aβ40 by PSH is nearly identical to that by γ-secretase. The proteolytic activity of PSH is specifically suppressed by presenilin-specific inhibitors. Known modulators of γ-secretase also modulate PSH similarly in terms of the Aβ42/Aβ40 ratio. Structural analysis reveals association of a known γ-secretase inhibitor with PSH between its two catalytic aspartate residues. These findings identify PSH as a surrogate protease for the screening of agents that may regulate the protease activity and the cleavage preference of γ-secretase.
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35
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Marinangeli C, Tasiaux B, Opsomer R, Hage S, Sodero AO, Dewachter I, Octave JN, Smith SO, Constantinescu SN, Kienlen-Campard P. Presenilin transmembrane domain 8 conserved AXXXAXXXG motifs are required for the activity of the γ-secretase complex. J Biol Chem 2015; 290:7169-84. [PMID: 25614624 DOI: 10.1074/jbc.m114.601286] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Understanding the molecular mechanisms controlling the physiological and pathological activity of γ-secretase represents a challenging task in Alzheimer disease research. The assembly and proteolytic activity of this enzyme require the correct interaction of the 19 transmembrane domains (TMDs) present in its four subunits, including presenilin (PS1 or PS2), the γ-secretase catalytic core. GXXXG and GXXXG-like motifs are critical for TMDs interactions as well as for protein folding and assembly. The GXXXG motifs on γ-secretase subunits (e.g. APH-1) or on γ-secretase substrates (e.g. APP) are known to be involved in γ-secretase assembly and in Aβ peptide production, respectively. We identified on PS1 and PS2 TMD8 two highly conserved AXXXAXXXG motifs. The presence of a mutation causing an inherited form of Alzheimer disease (familial Alzheimer disease) in the PS1 motif suggested their involvement in the physiopathological configuration of the γ-secretase complex. In this study, we targeted the role of these motifs on TMD8 of PSs, focusing on their role in PS assembly and catalytic activity. Each motif was mutated, and the impact on complex assembly, activity, and substrate docking was monitored. Different amino acid substitutions on the same motif resulted in opposite effects on γ-secretase activity, without affecting the assembly or significantly impairing the maturation of the complex. Our data suggest that AXXXAXXXG motifs in PS TMD8 are key determinants for the conformation of the mature γ-secretase complex, participating in the switch between the physiological and pathological functional conformations of the γ-secretase.
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Affiliation(s)
| | | | | | - Salim Hage
- the Louvain Drug Research Institute, and
| | | | | | | | - Steven O Smith
- the Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794-5215
| | - Stefan N Constantinescu
- the de Duve Institute and Ludwig Institute for Cancer Research, Université Catholique de Louvain, Brussels 1200, Belgium and
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36
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Chen WT, Hsieh YF, Huang YJ, Lin CC, Lin YT, Liu YC, Lien CC, Cheng IHJ. G206D Mutation of Presenilin-1 Reduces Pen2 Interaction, Increases Aβ42/Aβ40 Ratio and Elevates ER Ca(2+) Accumulation. Mol Neurobiol 2014; 52:1835-1849. [PMID: 25394380 DOI: 10.1007/s12035-014-8969-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 10/28/2014] [Indexed: 12/23/2022]
Abstract
Early-onset familial Alzheimer's disease (AD) is most commonly associated with the mutations in presenilin-1 (PS1). PS1 is the catalytic component of the γ-secretase complex, which cleaves amyloid precursor protein to produce amyloid-β (Aβ), the major cause of AD. Presenilin enhancer 2 (Pen2) is critical for activating γ-secretase and exporting PS1 from endoplasmic reticulum (ER). Among all the familial AD-linked PS1 mutations, mutations at the G206 amino acid are the most adjacent position to the Pen2 binding site. Here, we characterized the effect of a familial AD-linked PS1 G206D mutation on the PS1-Pen2 interaction and the accompanied alteration in γ-secretase-dependent and -independent functions. We found that the G206D mutation reduced PS1-Pen2 interaction, but did not abolish γ-secretase formation and PS1 endoproteolysis. For γ-secretase-dependent function, the G206D mutation increased Aβ42 production but not Notch cleavage. For γ-secretase-independent function, this mutation disrupted the ER calcium homeostasis but not lysosomal calcium homeostasis and autophagosome maturation. Impaired ER calcium homeostasis may due to the reduced mutant PS1 level in the ER. Although this mutation did not alter the cell survival under stress, both increased Aβ42 ratio and disturbed ER calcium regulation could be the mechanisms underlying the pathogenesis of the familial AD-linked PS1 G206D mutation.
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Affiliation(s)
- Wei-Ting Chen
- Taiwan International Graduate Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei, Taiwan.,Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.,Institute of Biochemistry and Molecular Biology, School of Life Science, National Yang-Ming University, Taipei, Taiwan
| | - Yi-Fang Hsieh
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Yan-Jing Huang
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Che-Ching Lin
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Yen-Tung Lin
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Yu-Chao Liu
- Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan
| | - Cheng-Chang Lien
- Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Irene Han-Juo Cheng
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan. .,Brain Research Center, National Yang-Ming University, Taipei, Taiwan. .,Infection and Immunity Research Center, National Yang-Ming University, Taipei, Taiwan. .,Immunology Center, Taipei Veterans General Hospital, Taipei, Taiwan. .,Institute of Brain Science, School of Medicine, National Yang-Ming University, No. 155, Sec. 2, Linong Street, Taipei, 112, Taiwan.
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37
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Villa JC, Chiu D, Brandes AH, Escorcia FE, Villa CH, Maguire WF, Hu CJ, de Stanchina E, Simon MC, Sisodia SS, Scheinberg DA, Li YM. Nontranscriptional role of Hif-1α in activation of γ-secretase and notch signaling in breast cancer. Cell Rep 2014; 8:1077-92. [PMID: 25131208 DOI: 10.1016/j.celrep.2014.07.028] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2012] [Revised: 03/04/2014] [Accepted: 07/16/2014] [Indexed: 12/11/2022] Open
Abstract
γ-Secretase is composed of four proteins that are obligatory for protease activity: presenilin, nicastrin, Aph1, and Pen-2. Despite the progress toward understanding the function of these individual subunits, there is no information available pertaining to the modulation of γ-secretase in response to environmental changes in cells. Here, we show that hypoxia upregulates γ-secretase activity through a direct interaction with Hif-1α, revealing an unconventional function for Hif-1α as an enzyme subunit, which is distinct from its canonical role as a transcription factor. Moreover, hypoxia-induced cell invasion and metastasis are alleviated by either γ-secretase inhibitors or a dominant-negative Notch coactivator, indicating that γ-secretase/Notch signaling plays an essential role in controlling these cellular processes. The present study reveals a mechanism in which γ-secretase can achieve temporal control through conditional interactions with regulatory proteins, such as Hif-1α, under select physiological and pathological conditions.
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Affiliation(s)
- Jennifer C Villa
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Danica Chiu
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Alissa H Brandes
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Freddy E Escorcia
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Carlos H Villa
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - William F Maguire
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Cheng-Jun Hu
- Molecular Biology Graduate Program, School of Dental Medicine, University of Colorado, Aurora, CO 80045, USA
| | - Elisa de Stanchina
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - M Celeste Simon
- Abramson Family Cancer Research Institute, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Sangram S Sisodia
- The Center for Molecular Neurobiology, The University of Chicago, Chicago, IL 60637, USA
| | - David A Scheinberg
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - Yue-Ming Li
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA.
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38
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Affiliation(s)
| | - Matthew Bogyo
- Departments of 1Chemical and Systems Biology,
- Microbiology and Immunology, and
- Pathology, Stanford University School of Medicine, Stanford, California 94305-5324;
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39
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Wagner SL, Zhang C, Cheng S, Nguyen P, Zhang X, Rynearson K, Wang R, Li Y, Sisodia SS, Mobley WC, Tanzi RE. Soluble γ-secretase modulators selectively inhibit the production of the 42-amino acid amyloid β peptide variant and augment the production of multiple carboxy-truncated amyloid β species. Biochemistry 2014; 53:702-13. [PMID: 24401146 PMCID: PMC3929337 DOI: 10.1021/bi401537v] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/07/2014] [Indexed: 02/05/2023]
Abstract
Alzheimer's disease (AD) is characterized pathologically by an abundance of extracellular neuritic plaques composed primarily of the 42-amino acid amyloid β peptide variant (Aβ42). In the majority of familial AD (FAD) cases, e.g., those harboring mutations in presenilin 1 (PS1), there is a relative increase in the levels of Aβ42 compared to the levels of Aβ40. We previously reported the characterization of a series of aminothiazole-bridged aromates termed aryl aminothiazole γ-secretase modulators or AGSMs [Kounnas, M. Z., et al. (2010) Neuron 67, 769-780] and showed their potential for use in the treatment of FAD [Wagner, S. L., et al. (2012) Arch. Neurol. 69, 1255-1258]. Here we describe a series of GSMs with physicochemical properties improved compared to those of AGSMs. Specific heterocycle replacements of the phenyl rings in AGSMs provided potent molecules with improved aqueous solubilities. A number of these soluble γ-secretase modulators (SGSMs) potently lowered Aβ42 levels without inhibiting proteolysis of Notch or causing accumulation of amyloid precursor protein carboxy-terminal fragments, even at concentrations approximately 1000-fold greater than their IC50 values for reducing Aβ42 levels. The effects of one potent SGSM on Aβ peptide production were verified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry, showing enhanced production of a number of carboxy-truncated Aβ species. This SGSM also inhibited Aβ42 peptide production in a highly purified reconstituted γ-secretase in vitro assay system and retained the ability to modulate γ-secretase-mediated proteolysis in a stably transfected cell culture model overexpressing a human PS1 mutation validating the potential for use in FAD.
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Affiliation(s)
- Steven L. Wagner
- Department
of Neurosciences, University of California,
San Diego, La Jolla, California 92093-0624, United States
| | - Can Zhang
- Genetics
and Aging Research Unit, Department of Neurology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
| | - Soan Cheng
- Department
of Neurosciences, University of California,
San Diego, La Jolla, California 92093-0624, United States
| | - Phuong Nguyen
- Department
of Neurosciences, University of California,
San Diego, La Jolla, California 92093-0624, United States
| | - Xulun Zhang
- The
Center for Molecular Neurobiology, University
of Chicago, Chicago, Illinois 60637, United
States
| | - Kevin
D. Rynearson
- Department
of Neurosciences, University of California,
San Diego, La Jolla, California 92093-0624, United States
| | - Rong Wang
- Department
of Genetics and Genomic Sciences, Icahn
Institute, New York, New York 10029, United
States
| | - Yueming Li
- Molecular
Pharmacology and Chemistry Program, Memorial
Sloan-Kettering Cancer Center, New York, New York 10065, United States
| | - Sangram S. Sisodia
- The
Center for Molecular Neurobiology, University
of Chicago, Chicago, Illinois 60637, United
States
| | - William C. Mobley
- Department
of Neurosciences, University of California,
San Diego, La Jolla, California 92093-0624, United States
| | - Rudolph E. Tanzi
- Genetics
and Aging Research Unit, Department of Neurology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States
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40
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Gertsik N, Ballard TE, Am Ende CW, Johnson DS, Li YM. Development of CBAP-BPyne, a probe for γ-secretase and presenilinase. MEDCHEMCOMM 2014; 5:338-341. [PMID: 24914408 DOI: 10.1039/c3md00281k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
γ-Secretase undergoes endoproteolysis of its catalytic subunit, presenilin (PS), to form PS N-terminal and C-terminal fragments (PS1-NTF/CTF), which generate the active site. PS endoproteolysis, catalyzed by presenilinase (PSase), remains poorly understood and requires novel chemical approaches for its mechanistic study. CBAP is a dual inhibitor that suppresses both γ-secretase and PSase activities. To probe γ-secretase and PSase activity in cells, we have synthesized the clickable photoaffinity probe CBAP-BPyne. We found that CBAP-BPyne specifically labels PS1-NTF and signal peptide peptidase (SPP). CBAP-BPyne is a valuable tool to directly study the mechanism of endoproteolysis.
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Affiliation(s)
- Natalya Gertsik
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA ; Biochemistry and Molecular Biology Program, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
| | - T Eric Ballard
- Pfizer Worldwide Research and Development, Neuroscience Medicinal Chemistry and Chemical Biology, Cambridge, MA 02139, USA ; Pfizer Worldwide Research and Development, Neuroscience Medicinal Chemistry, Groton, CT 06340, USA
| | - Christopher W Am Ende
- Pfizer Worldwide Research and Development, Neuroscience Medicinal Chemistry, Groton, CT 06340, USA
| | - Douglas S Johnson
- Pfizer Worldwide Research and Development, Neuroscience Medicinal Chemistry and Chemical Biology, Cambridge, MA 02139, USA
| | - Yue-Ming Li
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
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41
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Wolfe MS. Toward the structure of presenilin/γ-secretase and presenilin homologs. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1828:2886-97. [PMID: 24099007 PMCID: PMC3801419 DOI: 10.1016/j.bbamem.2013.04.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 04/03/2013] [Accepted: 04/11/2013] [Indexed: 01/30/2023]
Abstract
Presenilin is the catalytic component of the γ-secretase complex, a membrane-embedded aspartyl protease that plays a central role in biology and in the pathogenesis of Alzheimer's disease. Upon assembly with its three protein cofactors (nicastrin, Aph-1 and Pen-2), presenilin undergoes autoproteolysis into two subunits, each of which contributes one of the catalytic aspartates to the active site. A family of presenilin homologs, including signal peptide peptidase, possess proteolytic activity without the need for other protein factors, and these simpler intramembrane aspartyl proteases have given insight into the action of presenilin within the γ-secretase complex. Cellular and molecular studies support a nine-transmembrane topology for presenilins and their homologs, and small-molecule inhibitors and cysteine scanning with crosslinking have suggested certain presenilin residues and regions that contribute to substrate recognition and handling. Identification of partial complexes has also offered clues to protein-protein interactions within the γ-secretase complex. Biophysical methods have allowed 3D views of the γ-secretase complex and presenilins. Most recently, the crystal structure of a microbial presenilin homolog has confirmed a nine-transmembrane topology and intramembranous location and proximity of the two conserved and essential aspartates. The crystal structure also provides a platform for the formulation of specific hypotheses regarding substrate interaction and catalysis as well as the pathogenic mechanism of Alzheimer-causing presenilin mutations. This article is part of a Special Issue entitled: Intramembrane Proteases.
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Affiliation(s)
- Michael S Wolfe
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, 77 Avenue Louis Pasteur, H.I.M. 754, Boston, MA 02115 USA.
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42
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Schon EA, Area-Gomez E. Mitochondria-associated ER membranes in Alzheimer disease. Mol Cell Neurosci 2013; 55:26-36. [DOI: 10.1016/j.mcn.2012.07.011] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 07/26/2012] [Accepted: 07/27/2012] [Indexed: 01/03/2023] Open
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43
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Crump CJ, Johnson DS, Li YM. Development and mechanism of γ-secretase modulators for Alzheimer's disease. Biochemistry 2013; 52:3197-216. [PMID: 23614767 DOI: 10.1021/bi400377p] [Citation(s) in RCA: 134] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
γ-Secretase is an aspartyl intramembranal protease composed of presenilin, Nicastrin, Aph1, and Pen2 with 19 transmembrane domains. γ-Secretase cleaves the amyloid precursor proteins (APP) to release Aβ peptides that likely play a causative role in the pathogenesis of Alzheimer's disease (AD). In addition, γ-secretase cleaves Notch and other type I membrane proteins. γ-Secretase inhibitors (GSIs) have been developed and used for clinical studies. However, clinical trials have shown adverse effects of GSIs that are potentially linked with nondiscriminatory inhibition of Notch signaling, overall APP processing, and other substrate cleavages. Therefore, these findings call for the development of disease-modifying agents that target γ-secretase activity to lower levels of Aβ42 production without blocking the overall processing of γ-secretase substrates. γ-Secretase modulators (GSMs) originally derived from nonsteroidal anti-inflammatory drugs (NSAIDs) display such characteristics and are the focus of this review. However, first-generation GSMs have limited potential because of the low potency and undesired neuropharmacokinetic properties. This generation of GSMs has been suggested to interact with the APP substrate, γ-secretase, or both. To improve the potency and brain availability, second-generation GSMs, including NSAID-derived carboxylic acid and non-NSAID-derived heterocyclic chemotypes, as well as natural product-derived GSMs have been developed. Animal studies of this generation of GSMs have shown encouraging preclinical profiles. Moreover, using potent GSM photoaffinity probes, multiple studies unambiguously have showed that both carboxylic acid and heterocyclic GSMs specifically target presenilin, the catalytic subunit of γ-secretase. In addition, two types of GSMs have distinct binding sites within the γ-secretase complex and exhibit different Aβ profiles. GSMs induce a conformational change of γ-secretase to achieve modulation. Various models are proposed and discussed. Despite the progress of GSM research, many outstanding issues remain to be investigated to achieve the ultimate goal of developing GSMs as effective AD therapies.
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Affiliation(s)
- Christina J Crump
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center , 1275 York Avenue, New York, New York 10065, United States
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44
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Liu F, Xue ZQ, Deng SH, Kun X, Luo XG, Patrylo PR, Rose GM, Cai H, Struble RG, Cai Y, Yan XX. γ-secretase binding sites in aged and Alzheimer's disease human cerebrum: the choroid plexus as a putative origin of CSF Aβ. Eur J Neurosci 2013; 37:1714-25. [PMID: 23432732 DOI: 10.1111/ejn.12159] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 12/15/2012] [Accepted: 01/17/2013] [Indexed: 01/05/2023]
Abstract
Deposition of β -amyloid (Aβ) peptides, cleavage products of β-amyloid precursor protein (APP) by β-secretase-1 (BACE1) and γ-secretase, is a neuropathological hallmark of Alzheimer's disease (AD). γ-Secretase inhibition is a therapeutical anti-Aβ approach, although changes in the enzyme's activity in AD brain are unclear. Cerebrospinal fluid (CSF) Aβ peptides are thought to derive from brain parenchyma and thus may serve as biomarkers for assessing cerebral amyloidosis and anti-Aβ efficacy. The present study compared active γ-secretase binding sites with Aβ deposition in aged and AD human cerebrum, and explored the possibility of Aβ production and secretion by the choroid plexus (CP). The specific binding density of [(3) H]-L-685,458, a radiolabeled high-affinity γ-secretase inhibitor, in the temporal neocortex and hippocampal formation was similar for AD and control cases with similar ages and post-mortem delays. The CP in post-mortem samples exhibited exceptionally high [(3) H]-L-685,458 binding density, with the estimated maximal binding sites (Bmax) reduced in the AD relative to control groups. Surgically resected human CP exhibited APP, BACE1 and presenilin-1 immunoreactivity, and β-site APP cleavage enzymatic activity. In primary culture, human CP cells also expressed these amyloidogenic proteins and released Aβ40 and Aβ42 into the medium. Overall, our results suggest that γ-secretase activity appears unaltered in the cerebrum in AD and is not correlated with regional amyloid plaque pathology. The CP appears to be a previously unrecognised non-neuronal contributor to CSF Aβ, probably at reduced levels in AD.
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Affiliation(s)
- Fei Liu
- Department of Neurosurgery, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
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45
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Pozdnyakov N, Murrey HE, Crump CJ, Pettersson M, Ballard TE, Am Ende CW, Ahn K, Li YM, Bales KR, Johnson DS. γ-Secretase modulator (GSM) photoaffinity probes reveal distinct allosteric binding sites on presenilin. J Biol Chem 2013; 288:9710-9720. [PMID: 23396974 DOI: 10.1074/jbc.m112.398602] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
γ-Secretase is an intramembrane aspartyl protease that cleaves the amyloid precursor protein to produce neurotoxic β-amyloid peptides (i.e. Aβ42) that have been implicated in the pathogenesis of Alzheimer disease. Small molecule γ-secretase modulators (GSMs) have emerged as potential disease-modifying treatments for Alzheimer disease because they reduce the formation of Aβ42 while not blocking the processing of γ-secretase substrates. We developed clickable GSM photoaffinity probes with the goal of identifying the target of various classes of GSMs and to better understand their mechanism of action. Here, we demonstrate that the photoaffinity probe E2012-BPyne specifically labels the N-terminal fragment of presenilin-1 (PS1-NTF) in cell membranes as well as in live cells and primary neuronal cultures. The labeling is competed in the presence of the parent imidazole GSM E2012, but not with acid GSM-1, allosteric GSI BMS-708163, or substrate docking site peptide inhibitor pep11, providing evidence that these compounds have distinct binding sites. Surprisingly, we found that the cross-linking of E2012-BPyne to PS1-NTF is significantly enhanced in the presence of the active site-directed GSI L-685,458 (L458). In contrast, L458 does not affect the labeling of the acid GSM photoprobe GSM-5. We also observed that E2012-BPyne specifically labels PS1-NTF (active γ-secretase) but not full-length PS1 (inactive γ-secretase) in ANP.24 cells. Taken together, our results support the hypothesis that multiple binding sites within the γ-secretase complex exist, each of which may contribute to different modes of modulatory action. Furthermore, the enhancement of PS1-NTF labeling by E2012-BPyne in the presence of L458 suggests a degree of cooperativity between the active site of γ-secretase and the modulatory binding site of certain GSMs.
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Affiliation(s)
- Nikolay Pozdnyakov
- Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139
| | - Heather E Murrey
- Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139
| | - Christina J Crump
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065; Department of Pharmacology, Weill Graduate School of Medical Science of Cornell University, New York, New York 10021
| | - Martin Pettersson
- Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139
| | - T Eric Ballard
- Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139
| | | | - Kwangwook Ahn
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065; Department of Pharmacology, Weill Graduate School of Medical Science of Cornell University, New York, New York 10021
| | - Yue-Ming Li
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065; Department of Pharmacology, Weill Graduate School of Medical Science of Cornell University, New York, New York 10021
| | - Kelly R Bales
- Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139.
| | - Douglas S Johnson
- Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139.
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46
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Pera M, Alcolea D, Sánchez-Valle R, Guardia-Laguarta C, Colom-Cadena M, Badiola N, Suárez-Calvet M, Lladó A, Barrera-Ocampo AA, Sepulveda-Falla D, Blesa R, Molinuevo JL, Clarimón J, Ferrer I, Gelpi E, Lleó A. Distinct patterns of APP processing in the CNS in autosomal-dominant and sporadic Alzheimer disease. Acta Neuropathol 2013; 125:201-13. [PMID: 23224319 PMCID: PMC3623032 DOI: 10.1007/s00401-012-1062-9] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 10/10/2012] [Accepted: 10/27/2012] [Indexed: 12/19/2022]
Abstract
Autosomal-dominant Alzheimer disease (ADAD) is a genetic disorder caused by
mutations in Amyloid Precursor Protein (APP) or
Presenilin (PSEN) genes. Studies from families
with ADAD have been critical to support the amyloid cascade hypothesis of Alzheimer
disease (AD), the basis for the current development of amyloid-based
disease-modifying therapies in sporadic AD (SAD). However, whether the pathological
changes in APP processing in the CNS in ADAD are similar to those observed in SAD
remains unclear. In this study, we measured β-site APP-cleaving enzyme (BACE) protein levels and activity, APP and
APP C-terminal fragments in brain samples from subjects with ADAD carrying APP or PSEN1 mutations
(n = 18), patients with SAD (n = 27) and age-matched controls (n = 22). We also measured sAPPβ and
BACE protein levels, as well as BACE activity, in CSF from individuals carrying
PSEN1 mutations (10 mutation carriers and 7
non-carrier controls), patients with SAD (n = 32)
and age-matched controls (n = 11). We found that
in the brain, the pattern in ADAD was characterized by an increase in APP β-C-terminal fragment (β-CTF) levels despite no changes in BACE protein levels or activity.
In contrast, the pattern in SAD in the brain was mainly characterized by an increase
in BACE levels and activity, with less APP β-CTF
accumulation than ADAD. In the CSF, no differences were found between groups in BACE
activity or expression or sAPPβ levels. Taken
together, these data suggest that the physiopathological events underlying the
chronic Aβ production/clearance imbalance in SAD
and ADAD are different. These differences should be considered in the design of
intervention trials in AD.
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Affiliation(s)
- Marta Pera
- Department of Neurology, Inst. Investigacions Biomediques, Hospital de Sant Pau, Universitat
Autònoma de Barcelona, Sant Antoni Mª Claret, 167, 08025 Barcelona, Spain
- Centro de Investigación Biomédica en Red en enfermedades
Neurodegenerativas, CIBERNED, Madrid, Spain
| | - Daniel Alcolea
- Department of Neurology, Inst. Investigacions Biomediques, Hospital de Sant Pau, Universitat
Autònoma de Barcelona, Sant Antoni Mª Claret, 167, 08025 Barcelona, Spain
- Centro de Investigación Biomédica en Red en enfermedades
Neurodegenerativas, CIBERNED, Madrid, Spain
| | - Raquel Sánchez-Valle
- Alzheimer’s Disease and other Cognitive Disorders Unit, Department of
Neurology, Hospital Clínic, Barcelona, Spain
| | - Cristina Guardia-Laguarta
- Department of Neurology, Inst. Investigacions Biomediques, Hospital de Sant Pau, Universitat
Autònoma de Barcelona, Sant Antoni Mª Claret, 167, 08025 Barcelona, Spain
- Centro de Investigación Biomédica en Red en enfermedades
Neurodegenerativas, CIBERNED, Madrid, Spain
| | - Martí Colom-Cadena
- Department of Neurology, Inst. Investigacions Biomediques, Hospital de Sant Pau, Universitat
Autònoma de Barcelona, Sant Antoni Mª Claret, 167, 08025 Barcelona, Spain
- Centro de Investigación Biomédica en Red en enfermedades
Neurodegenerativas, CIBERNED, Madrid, Spain
| | - Nahuai Badiola
- Department of Neurology, Inst. Investigacions Biomediques, Hospital de Sant Pau, Universitat
Autònoma de Barcelona, Sant Antoni Mª Claret, 167, 08025 Barcelona, Spain
- Centro de Investigación Biomédica en Red en enfermedades
Neurodegenerativas, CIBERNED, Madrid, Spain
| | - Marc Suárez-Calvet
- Department of Neurology, Inst. Investigacions Biomediques, Hospital de Sant Pau, Universitat
Autònoma de Barcelona, Sant Antoni Mª Claret, 167, 08025 Barcelona, Spain
- Centro de Investigación Biomédica en Red en enfermedades
Neurodegenerativas, CIBERNED, Madrid, Spain
| | - Albert Lladó
- Alzheimer’s Disease and other Cognitive Disorders Unit, Department of
Neurology, Hospital Clínic, Barcelona, Spain
| | - Alvaro A. Barrera-Ocampo
- Institute of Neuropathology, University Medical Center
Hamburg-Eppendorf, Hamburg, Germany
- Grupo de Neurociencias de Antioquia, Faculty of Medicine, University of Antioquia, Medellín, Colombia
| | - Diego Sepulveda-Falla
- Institute of Neuropathology, University Medical Center
Hamburg-Eppendorf, Hamburg, Germany
- Grupo de Neurociencias de Antioquia, Faculty of Medicine, University of Antioquia, Medellín, Colombia
| | - Rafael Blesa
- Department of Neurology, Inst. Investigacions Biomediques, Hospital de Sant Pau, Universitat
Autònoma de Barcelona, Sant Antoni Mª Claret, 167, 08025 Barcelona, Spain
- Centro de Investigación Biomédica en Red en enfermedades
Neurodegenerativas, CIBERNED, Madrid, Spain
| | - José L. Molinuevo
- Alzheimer’s Disease and other Cognitive Disorders Unit, Department of
Neurology, Hospital Clínic, Barcelona, Spain
| | - Jordi Clarimón
- Department of Neurology, Inst. Investigacions Biomediques, Hospital de Sant Pau, Universitat
Autònoma de Barcelona, Sant Antoni Mª Claret, 167, 08025 Barcelona, Spain
- Centro de Investigación Biomédica en Red en enfermedades
Neurodegenerativas, CIBERNED, Madrid, Spain
| | - Isidre Ferrer
- Centro de Investigación Biomédica en Red en enfermedades
Neurodegenerativas, CIBERNED, Madrid, Spain
- Institut de Neuropatología, Servei Anatomia Patológica, IDIBELL,
Hospital Universitari de Bellvitge, University of Barcelona, Barcelona, Spain
| | - Ellen Gelpi
- Neurological Tissue Bank, Biobanc-Hospital Clínic-IDIBAPS, Barcelona, Spain
| | - Alberto Lleó
- Department of Neurology, Inst. Investigacions Biomediques, Hospital de Sant Pau, Universitat
Autònoma de Barcelona, Sant Antoni Mª Claret, 167, 08025 Barcelona, Spain
- Centro de Investigación Biomédica en Red en enfermedades
Neurodegenerativas, CIBERNED, Madrid, Spain
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Svedružić ŽM, Popović K, Šendula-Jengić V. Modulators of γ-secretase activity can facilitate the toxic side-effects and pathogenesis of Alzheimer's disease. PLoS One 2013; 8:e50759. [PMID: 23308095 PMCID: PMC3538728 DOI: 10.1371/journal.pone.0050759] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 10/25/2012] [Indexed: 11/18/2022] Open
Abstract
Background Selective modulation of different Aβ products of an intramembrane protease γ-secretase, could be the most promising strategy for development of effective therapies for Alzheimer's disease. We describe how different drug-candidates can modulate γ-secretase activity in cells, by studying how DAPT affects changes in γ-secretase activity caused by gradual increase in Aβ metabolism. Results Aβ 1–40 secretion in the presence of DAPT shows biphasic activation-inhibition dose-response curves. The biphasic mechanism is a result of modulation of γ-secretase activity by multiple substrate and inhibitor molecules that can bind to the enzyme simultaneously. The activation is due to an increase in γ-secretase's kinetic affinity for its substrate, which can make the enzyme increasingly more saturated with otherwise sub-saturating substrate. The noncompetitive inhibition that prevails at the saturating substrate can decrease the maximal activity. The synergistic activation-inhibition effects can drastically reduce γ-secretase's capacity to process its physiological substrates. This reduction makes the biphasic inhibitors exceptionally prone to the toxic side-effects and potentially pathogenic. Without the modulation, γ-secretase activity on it physiological substrate in cells is only 14% of its maximal activity, and far below the saturation. Significance Presented mechanism can explain why moderate inhibition of γ-secretase cannot lead to effective therapies, the pharmacodynamics of Aβ-rebound phenomenon, and recent failures of the major drug-candidates such as semagacestat. Novel improved drug-candidates can be prepared from competitive inhibitors that can bind to different sites on γ-secretase simultaneously. Our quantitative analysis of the catalytic capacity can facilitate the future studies of the therapeutic potential of γ-secretase and the pathogenic changes in Aβ metabolism.
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Affiliation(s)
- Željko M Svedružić
- Medical Biochemistry, PB Rab, Faculty of Medicine, University of Rijeka, Rab, Croatia.
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Thathiah A, Horré K, Snellinx A, Vandewyer E, Huang Y, Ciesielska M, De Kloe G, Munck S, De Strooper B. β-arrestin 2 regulates Aβ generation and γ-secretase activity in Alzheimer's disease. Nat Med 2012. [PMID: 23202293 DOI: 10.1038/nm.3023] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
β-arrestins are associated with numerous aspects of G protein-coupled receptor (GPCR) signaling and regulation and accordingly influence diverse physiological and pathophysiological processes. Here we report that β-arrestin 2 expression is elevated in two independent cohorts of individuals with Alzheimer's disease. Overexpression of β-arrestin 2 leads to an increase in amyloid-β (Aβ) peptide generation, whereas genetic silencing of Arrb2 (encoding β-arrestin 2) reduces generation of Aβ in cell cultures and in Arrb2(-/-) mice. Moreover, in a transgenic mouse model of Alzheimer's disease, genetic deletion of Arrb2 leads to a reduction in the production of Aβ(40) and Aβ(42). Two GPCRs implicated previously in Alzheimer's disease (GPR3 and the β(2)-adrenergic receptor) mediate their effects on Aβ generation through interaction with β-arrestin 2. β-arrestin 2 physically associates with the Aph-1a subunit of the γ-secretase complex and redistributes the complex toward detergent-resistant membranes, increasing the catalytic activity of the complex. Collectively, these studies identify β-arrestin 2 as a new therapeutic target for reducing amyloid pathology and GPCR dysfunction in Alzheimer's disease.
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Affiliation(s)
- Amantha Thathiah
- Vlaams Instituut voor Biotechnologie Center for the Biology of Disease, Leuven, Belgium
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Crump CJ, Castro SV, Wang F, Pozdnyakov N, Ballard TE, Sisodia SS, Bales KR, Johnson DS, Li YM. BMS-708,163 targets presenilin and lacks notch-sparing activity. Biochemistry 2012; 51:7209-11. [PMID: 22931393 DOI: 10.1021/bi301137h] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The "Notch-sparing" γ-secretase inhibitor (GSI) BMS-708,163 (Avagacestat) is currently in phase II clinical trials for Alzheimer's disease. Unlike previously failed GSIs, BMS-708,163 is considered to be a promising drug candidate because of its reported Notch-sparing activity for the inhibition of Aβ production over Notch cleavage. We now report that BMS-708,163 binds directly to the presenilin-1 N-terminal fragment and that binding can be challenged by other pan-GSIs, but not by γ-secretase modulators. Furthermore, BMS-708,163 blocks the binding of four different active site-directed GSI photoaffinity probes. We therefore report that this compound acts as a nonselective γ-secretase inhibitor.
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Affiliation(s)
- Christina J Crump
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, United States
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50
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Upregulated function of mitochondria-associated ER membranes in Alzheimer disease. EMBO J 2012; 31:4106-23. [PMID: 22892566 PMCID: PMC3492725 DOI: 10.1038/emboj.2012.202] [Citation(s) in RCA: 503] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 06/28/2012] [Indexed: 12/12/2022] Open
Abstract
Alzheimer disease (AD) associated (gamma)-secretase components presenilin-1 and -2 accumulate in MAM, an LR-like ER subcompartment connected to mitochondria. MAM function increases in patients with familial or sporadic AD and may be linked to AD pathogenesis. Alzheimer disease (AD) is associated with aberrant processing of the amyloid precursor protein (APP) by γ-secretase, via an unknown mechanism. We recently showed that presenilin-1 and -2, the catalytic components of γ-secretase, and γ-secretase activity itself, are highly enriched in a subcompartment of the endoplasmic reticulum (ER) that is physically and biochemically connected to mitochondria, called mitochondria-associated ER membranes (MAMs). We now show that MAM function and ER–mitochondrial communication—as measured by cholesteryl ester and phospholipid synthesis, respectively—are increased significantly in presenilin-mutant cells and in fibroblasts from patients with both the familial and sporadic forms of AD. We also show that MAM is an intracellular detergent-resistant lipid raft (LR)-like domain, consistent with the known presence of presenilins and γ-secretase activity in rafts. These findings may help explain not only the aberrant APP processing but also a number of other biochemical features of AD, including altered lipid metabolism and calcium homeostasis. We propose that upregulated MAM function at the ER–mitochondrial interface, and increased cross-talk between these two organelles, may play a hitherto unrecognized role in the pathogenesis of AD.
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