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Dong J, Qin W, Wei C, Tang Y, Wang Q, Jia J. A Novel PSEN1 K311R Mutation Discovered in Chinese Families with Late-Onset Alzheimer's Disease Affects Amyloid-β Production and Tau Phosphorylation. J Alzheimers Dis 2018; 57:613-623. [PMID: 28269784 DOI: 10.3233/jad-161188] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Presenilin-1 (PSEN1) is the most frequently mutated gene in familial Alzheimer's disease (AD), whereas only several novel mutations have been reported in China and functional studies were seldom conducted. OBJECTIVE We describe a novel PSEN1 K311R mutation in two Chinese families with late-onset AD and its functional impact on amyloid-β protein precursor (AβPP) processing and tau phosphorylation. METHODS The mutation was detected by direct sequencing of PSEN1 exon 9. HEK293 cells stably expressing wild-type APP695 (HEK293-APP695wt) were transfected with plasmids containing human wild-type PSEN1, PSEN1 K311R mutation, and PSEN1 E280A mutation to compare the K311R mutation's effects on AβPP processing with other groups. In addition, each group of cells were co-transfected with plasmids harboring PSEN1 and human wild-type MAPT complementary DNA to study the mutation's impacts on tau phosphorylation. RESULTS The K311R mutation was detected in probands of two late-onset AD families. Expression of the K311R or E280A mutation increased amyloid-β (Aβ)42 levels but decreased Aβ40 levels, resulting in an overall increase in the Aβ42/Aβ40 ratio compared to those in wild-type PSEN1 transfected cells (p < 0.05). The K311R or E280A mutation also increased the levels of phosphorylated tau compared to wild-type PSEN1 (p < 0.05). CONCLUSION The K311R mutation might contribute to AD pathogenesis by overproducing toxic Aβ species and enhancing tau phosphorylation. Further in-depth studies are needed to decipher the pathogenic mechanisms of the K311R mutation in terms of AβPP cleavage, tau phosphorylation, and other presenilin-1 mediated functional pathways.
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Affiliation(s)
- Jing Dong
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, P.R. China
| | - Wei Qin
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, P.R. China.,Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, P.R. China.,Beijing Key Laboratory of Geriatric Cognitive Disorders, Beijing, P.R. China.,Key Neurodegenerative Laboratory of the Ministry of Education of the People's Republic of China, Beijing, P.R. China
| | - Cuibai Wei
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, P.R. China.,Beijing Key Laboratory of Geriatric Cognitive Disorders, Beijing, P.R. China.,Key Neurodegenerative Laboratory of the Ministry of Education of the People's Republic of China, Beijing, P.R. China
| | - Yi Tang
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, P.R. China
| | - Qi Wang
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, P.R. China.,Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, P.R. China.,Beijing Key Laboratory of Geriatric Cognitive Disorders, Beijing, P.R. China.,Key Neurodegenerative Laboratory of the Ministry of Education of the People's Republic of China, Beijing, P.R. China
| | - Jianping Jia
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, P.R. China.,Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, P.R. China.,Beijing Key Laboratory of Geriatric Cognitive Disorders, Beijing, P.R. China.,Key Neurodegenerative Laboratory of the Ministry of Education of the People's Republic of China, Beijing, P.R. China
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2
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Le Guennec K, Veugelen S, Quenez O, Szaruga M, Rousseau S, Nicolas G, Wallon D, Fluchere F, Frébourg T, De Strooper B, Campion D, Chávez-Gutiérrez L, Rovelet-Lecrux A. Deletion of exons 9 and 10 of the Presenilin 1 gene in a patient with Early-onset Alzheimer Disease generates longer amyloid seeds. Neurobiol Dis 2017; 104:97-103. [PMID: 28461250 DOI: 10.1016/j.nbd.2017.04.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 03/27/2017] [Accepted: 04/27/2017] [Indexed: 11/18/2022] Open
Abstract
Presenilin 1 (PSEN1) mutations are the main cause of autosomal dominant Early-onset Alzheimer Disease (EOAD). Among them, deletions of exon 9 have been reported to be associated with a phenotype of spastic paraparesis. Using exome data from a large sample of 522 EOAD cases and 584 controls to search for genomic copy-number variations (CNVs), we report here a novel partial, in-frame deletion of PSEN1, removing both exons 9 and 10. The patient presented with memory impairment associated with spastic paraparesis, both starting from the age of 56years. He presented a positive family history of EOAD. We performed functional analysis to elucidate the impact of this novel deletion on PSEN1 activity as part of the γ-secretase complex. The deletion does not affect the assembly of a mature protease complex but has an extreme impact on its global endopeptidase activity. The mutant carboxypeptidase-like activity is also strongly impaired and the deleterious mutant effect leads to an incomplete digestion of long Aβ peptides and enhances the production of Aβ43, which has been shown to be potently amyloidogenic and neurotoxic in vivo.
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Affiliation(s)
- Kilan Le Guennec
- Normandie Univ, UNIROUEN, Inserm U1245, Rouen University Hospital, Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, F 76000 Rouen, France
| | - Sarah Veugelen
- VIB - Center for Brain and Disease Research, University of Leuven, 3000 Leuven, Belgium; Center for Human Genetics, Leuven Research Institute for Neuroscience & Disease (LIND), University of Leuven, 3000 Leuven, Belgium
| | - Olivier Quenez
- Normandie Univ, UNIROUEN, Inserm U1245, Rouen University Hospital, Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, F 76000 Rouen, France
| | - Maria Szaruga
- VIB - Center for Brain and Disease Research, University of Leuven, 3000 Leuven, Belgium; Center for Human Genetics, Leuven Research Institute for Neuroscience & Disease (LIND), University of Leuven, 3000 Leuven, Belgium
| | - Stéphane Rousseau
- Normandie Univ, UNIROUEN, Inserm U1245, Rouen University Hospital, Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, F 76000 Rouen, France
| | - Gaël Nicolas
- Normandie Univ, UNIROUEN, Inserm U1245, Rouen University Hospital, Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, F 76000 Rouen, France
| | - David Wallon
- Normandie Univ, UNIROUEN, Inserm U1245, Rouen University Hospital, Department of Neurology and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, F 76000 Rouen, France
| | - Frédérique Fluchere
- Department of Neurology and Movement Disorders, APHM, La Timone, Pôle de Neurosciences cliniques, Aix-Marseille Univ, Marseille, France
| | - Thierry Frébourg
- Normandie Univ, UNIROUEN, Inserm U1245, Rouen University Hospital, Department of Genetics, Normandy Center for Genomic and Personalized Medicine, F 76000 Rouen, France
| | - Bart De Strooper
- VIB - Center for Brain and Disease Research, University of Leuven, 3000 Leuven, Belgium; Center for Human Genetics, Leuven Research Institute for Neuroscience & Disease (LIND), University of Leuven, 3000 Leuven, Belgium; Institute of Neurology, University College London, Queen Square, WC1N 3BG London, UK
| | - Dominique Campion
- Normandie Univ, UNIROUEN, Inserm U1245, Rouen University Hospital, Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, F 76000 Rouen, France; Department of Research, Rouvray Psychiatric Hospital, Sotteville-lès-Rouen, France
| | - Lucía Chávez-Gutiérrez
- VIB - Center for Brain and Disease Research, University of Leuven, 3000 Leuven, Belgium; Center for Human Genetics, Leuven Research Institute for Neuroscience & Disease (LIND), University of Leuven, 3000 Leuven, Belgium
| | - Anne Rovelet-Lecrux
- Normandie Univ, UNIROUEN, Inserm U1245, Rouen University Hospital, Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, F 76000 Rouen, France.
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3
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Audrain M, Fol R, Dutar P, Potier B, Billard JM, Flament J, Alves S, Burlot MA, Dufayet-Chaffaud G, Bemelmans AP, Valette J, Hantraye P, Déglon N, Cartier N, Braudeau J. Alzheimer's disease-like APP processing in wild-type mice identifies synaptic defects as initial steps of disease progression. Mol Neurodegener 2016; 11:5. [PMID: 26759118 PMCID: PMC4709894 DOI: 10.1186/s13024-016-0070-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 01/06/2016] [Indexed: 12/15/2022] Open
Abstract
Background Alzheimer’s disease (AD) is the most frequent form of dementia in the elderly and no effective treatment is currently available. The mechanisms triggering AD onset and progression are still imperfectly dissected. We aimed at deciphering the modifications occurring in vivo during the very early stages of AD, before the development of amyloid deposits, neurofibrillary tangles, neuronal death and inflammation. Most current AD models based on Amyloid Precursor Protein (APP) overproduction beginning from in utero, to rapidly reproduce the histological and behavioral features of the disease within a few months, are not appropriate to study the early steps of AD development. As a means to mimic in vivo amyloid APP processing closer to the human situation in AD, we used an adeno-associated virus (AAV)-based transfer of human mutant APP and Presenilin 1 (PS1) genes to the hippocampi of two-month-old C57Bl/6 J mice to express human APP, without significant overexpression and to specifically induce its amyloid processing. Results The human APP, βCTF and Aβ42/40 ratio were similar to those in hippocampal tissues from AD patients. Three months after injection the murine Tau protein was hyperphosphorylated and rapid synaptic failure occurred characterized by decreased levels of both PSD-95 and metabolites related to neuromodulation, on proton magnetic resonance spectroscopy (1H-MRS). Astrocytic GLT-1 transporter levels were lower and the tonic glutamatergic current was stronger on electrophysiological recordings of CA1 hippocampal region, revealing the overstimulation of extrasynaptic N-methyl D-aspartate receptor (NMDAR) which precedes the loss of long-term potentiation (LTP). These modifications were associated with early behavioral impairments in the Open-field, Y-maze and Morris Mater Maze tasks. Conclusions Altogether, this demonstrates that an AD-like APP processing, yielding to levels of APP, βCTF and Aβ42/Aβ40 ratio similar to those observed in AD patients, are sufficient to rapidly trigger early steps of the amyloidogenic and Tau pathways in vivo. With this strategy, we identified a sequence of early events likely to account for disease onset and described a model that may facilitate efforts to decipher the factors triggering AD and to evaluate early neuroprotective strategies. Electronic supplementary material The online version of this article (doi:10.1186/s13024-016-0070-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mickael Audrain
- INSERM UMR1169, Université Paris-Sud, Université Paris-Saclay, Orsay, 94100, France.,Université Paris Descartes, Paris, France.,CEA, DSV, I2BM, MIRCen, Fontenay-aux-Roses, 92265, France
| | - Romain Fol
- INSERM UMR1169, Université Paris-Sud, Université Paris-Saclay, Orsay, 94100, France.,Université Paris Descartes, Paris, France.,CEA, DSV, I2BM, MIRCen, Fontenay-aux-Roses, 92265, France
| | - Patrick Dutar
- INSERM UMR894, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Brigitte Potier
- INSERM UMR894, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Jean-Marie Billard
- INSERM UMR894, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Julien Flament
- CEA, DSV, I2BM, MIRCen, Fontenay-aux-Roses, 92265, France.,INSERM UMS27, Fontenay-aux-Roses 92265, Université Paris-Sud, Université Paris-Saclay, Orsay, 94100, France
| | - Sandro Alves
- INSERM UMR1169, Université Paris-Sud, Université Paris-Saclay, Orsay, 94100, France.,CEA, DSV, I2BM, MIRCen, Fontenay-aux-Roses, 92265, France
| | - Marie-Anne Burlot
- INSERM UMR1169, Université Paris-Sud, Université Paris-Saclay, Orsay, 94100, France.,Université Paris Descartes, Paris, France.,CEA, DSV, I2BM, MIRCen, Fontenay-aux-Roses, 92265, France
| | - Gaelle Dufayet-Chaffaud
- INSERM UMR1169, Université Paris-Sud, Université Paris-Saclay, Orsay, 94100, France.,CEA, DSV, I2BM, MIRCen, Fontenay-aux-Roses, 92265, France
| | - Alexis-Pierre Bemelmans
- CEA, DSV, I2BM, MIRCen, Fontenay-aux-Roses, 92265, France.,CNRS UMR9199, Fontenay-aux-Roses 92265, Université Paris-Sud, Université Paris-Saclay, Orsay, 94100, France
| | - Julien Valette
- CEA, DSV, I2BM, MIRCen, Fontenay-aux-Roses, 92265, France.,CNRS UMR9199, Fontenay-aux-Roses 92265, Université Paris-Sud, Université Paris-Saclay, Orsay, 94100, France
| | - Philippe Hantraye
- CEA, DSV, I2BM, MIRCen, Fontenay-aux-Roses, 92265, France.,INSERM UMS27, Fontenay-aux-Roses 92265, Université Paris-Sud, Université Paris-Saclay, Orsay, 94100, France.,CNRS UMR9199, Fontenay-aux-Roses 92265, Université Paris-Sud, Université Paris-Saclay, Orsay, 94100, France
| | - Nicole Déglon
- Department of Clinical Neurosciences, Laboratory of Cellular and Molecular Neurotherapies, Lausanne University Hospital, Lausanne, Switzerland.,Neuroscience Research Center, Laboratory of Cellular and Molecular Neurotherapies, Lausanne University Hospital, Lausanne, Switzerland
| | - Nathalie Cartier
- INSERM UMR1169, Université Paris-Sud, Université Paris-Saclay, Orsay, 94100, France. .,CEA, DSV, I2BM, MIRCen, Fontenay-aux-Roses, 92265, France.
| | - Jérome Braudeau
- INSERM UMR1169, Université Paris-Sud, Université Paris-Saclay, Orsay, 94100, France.,CEA, DSV, I2BM, MIRCen, Fontenay-aux-Roses, 92265, France
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4
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Zheng ZZ, Chao ML, Fan ZB, Zhao YJ, Song HS. Molecular cloning and characterization of presenilin gene in Bombyx mori. Mol Med Rep 2015; 12:5508-16. [PMID: 26133988 DOI: 10.3892/mmr.2015.4019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 06/05/2015] [Indexed: 11/06/2022] Open
Abstract
Presenilin (PS), the catalytic core of the γ-secretase complex, is considered to be a causative protein of the early‑onset familial form of Alzheimer's disease. Aging is a risk factor for Alzheimer's disease and a number of genetic studies have utilized Bombyx mori (B. mori) as a model, making it possible to use B. mori to investigate Alzheimer's disease. However, the homologous gene of human PS in B. mori has remained to be elucidated. In the present study, the PS homologue gene in B. mori was identified and characterized, and six B. mori presenilin (BmPS) mRNA transcripts were generated by selecting multiple transcription start sites and/or alternative splice sites. The longest mRNA of BmPS (termed BmPS1) contains a 153 nt 5' untranslated region (UTR), a 1,440 nt open reading frame and a 1,063 nt 3' UTR. The predicted protein of BmPS1 consists of 479 amino acid residues and has two highly‑conserved aspartate residues, which form the catalytic core of aspartic proteases. It exhibits a sequence identity of ~44 and 51% with homologues in Homo sapiens and Drosophila melanogaster, respectively. However, the amino acid sequence of the BmPS loop region does not completely match between the two B. mori strains R13Q and Dazao. Genomic analysis revealed that B. mori had a single copy of the BmPS gene, which was composed of 14 exons. A total of four isoforms of BmPS (BmPS‑A, ‑B, ‑C and ‑D) owing to multiple transcriptional start sites and alternative splice sites were identified. The alternative splicing events occurring in the loop region improved the diversity of the BmPS protein and were detectable in all tissues, as determined using reverse transcription quantitative polymerase chain reaction (RT‑qPCR). Furthermore, the expression levels of BmPS in the brain at different developmental stages were detected using RT‑qPCR, and significantly higher expression levels of BmPS were found in the adult stage compared with those in the larval and pupal stages. The present study on BmPS provided insight into the pathogenesis of Alzheimer's disease and mechanisms of silkworm developmental regulation.
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Affiliation(s)
- Zeng-Zhang Zheng
- Department of Neurosciences, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China
| | - Meng-Ling Chao
- Department of Neurosciences, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China
| | - Zong-Biao Fan
- Department of Neurosciences, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China
| | - Yi-Jiao Zhao
- Department of Neurosciences, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China
| | - Hong-Sheng Song
- Department of Neurosciences, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China
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5
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Wanngren J, Lara P, Ojemalm K, Maioli S, Moradi N, Chen L, Tjernberg LO, Lundkvist J, Nilsson I, Karlström H. Changed membrane integration and catalytic site conformation are two mechanisms behind the increased Aβ42/Aβ40 ratio by presenilin 1 familial Alzheimer-linked mutations. FEBS Open Bio 2014; 4:393-406. [PMID: 24918054 PMCID: PMC4050182 DOI: 10.1016/j.fob.2014.04.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 04/16/2014] [Accepted: 04/17/2014] [Indexed: 01/11/2023] Open
Abstract
Familial Alzheimer disease (FAD) mutations affect presenilin membrane integration. The transmembrane domains around the catalytic site are vulnerable to changes. All FAD mutations cause changes in the active site of the γ-secretase complex. The FAD mutants lead to a complex processing pattern of the amyloid precursor protein.
The enzyme complex γ-secretase generates amyloid β-peptide (Aβ), a 37–43-residue peptide associated with Alzheimer disease (AD). Mutations in presenilin 1 (PS1), the catalytical subunit of γ-secretase, result in familial AD (FAD). A unifying theme among FAD mutations is an alteration in the ratio Aβ species produced (the Aβ42/Aβ40 ratio), but the molecular mechanisms responsible remain elusive. In this report we have studied the impact of several different PS1 FAD mutations on the integration of selected PS1 transmembrane domains and on PS1 active site conformation, and whether any effects translate to a particular amyloid precursor protein (APP) processing phenotype. Most mutations studied caused an increase in the Aβ42/Aβ40 ratio, but via different mechanisms. The mutations that caused a particular large increase in the Aβ42/Aβ40 ratio did also display an impaired APP intracellular domain (AICD) formation and a lower total Aβ production. Interestingly, seven mutations close to the catalytic site caused a severely impaired integration of proximal transmembrane/hydrophobic sequences into the membrane. This structural defect did not correlate to a particular APP processing phenotype. Six selected FAD mutations, all of which exhibited different APP processing profiles and impact on PS1 transmembrane domain integration, were found to display an altered active site conformation. Combined, our data suggest that FAD mutations affect the PS1 structure and active site differently, resulting in several complex APP processing phenotypes, where the most aggressive mutations in terms of increased Aβ42/Aβ40 ratio are associated with a decrease in total γ-secretase activity.
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Key Words
- AD, Alzheimer disease
- AICD, amyloid precursor protein intracellular domain
- APP, amyloid precursor protein
- Alzheimer disease
- Amyloid β-peptide
- Aβ, amyloid-β peptide
- BD8, blastocyst-derived embryonic stem cells
- Bis-Tris, 2-(bis(2-hydroxyethyl)amino)-2-(hydroxymethyl)propane-1,3-diol
- CHAPSO, 3-[(3-cholamidopropyl)dimethylammonio]-2-hydroxy-1-propanesulfonic acid
- CRM, column-washed dog pancreas rough microsomes
- CTF, C-terminal fragment
- ER, endoplasmic reticulum
- Endo H, endoglycosidase H
- FAD, familial AD
- FLIM/FRET, Fluorescence Lifetime Imaging/ Fluorescence Resonance Energy Transfer
- GCB, γ-secretase inhibitor coupled to biotin
- GVP, Gal4VP16
- Lep, leader peptidase
- MGD, minimal glycosylation distance
- MSD, Meso Scale Discovery
- Membrane integration
- NTF, N-terminal fragment
- PS, presenilin
- Protein structure
- RM, rough microsomes
- TMD, transmembrane domains
- WT, wild type
- γ-Secretase
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Affiliation(s)
- Johanna Wanngren
- Department of NVS, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Patricia Lara
- Department of Biochemistry & Biophysics, Stockholm University, Stockholm, Sweden
| | - Karin Ojemalm
- Department of Biochemistry & Biophysics, Stockholm University, Stockholm, Sweden
| | - Silvia Maioli
- Department of NVS, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Nasim Moradi
- Department of Biochemistry & Biophysics, Stockholm University, Stockholm, Sweden
| | - Lu Chen
- Department of Biochemistry & Biophysics, Stockholm University, Stockholm, Sweden
| | - Lars O Tjernberg
- Department of NVS, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | | | - IngMarie Nilsson
- Department of Biochemistry & Biophysics, Stockholm University, Stockholm, Sweden
| | - Helena Karlström
- Department of NVS, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
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6
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A novel presenilin 1 mutation (Ala275Val) as cause of early-onset familial Alzheimer disease. Neurosci Lett 2014; 566:115-9. [DOI: 10.1016/j.neulet.2014.02.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/22/2014] [Accepted: 02/17/2014] [Indexed: 11/23/2022]
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7
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Sharman MJ, Moussavi Nik SH, Chen MM, Ong D, Wijaya L, Laws SM, Taddei K, Newman M, Lardelli M, Martins RN, Verdile G. The Guinea Pig as a Model for Sporadic Alzheimer's Disease (AD): The Impact of Cholesterol Intake on Expression of AD-Related Genes. PLoS One 2013; 8:e66235. [PMID: 23805206 PMCID: PMC3689723 DOI: 10.1371/journal.pone.0066235] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 05/02/2013] [Indexed: 11/25/2022] Open
Abstract
We investigated the guinea pig, Cavia porcellus, as a model for Alzheimer’s disease (AD), both in terms of the conservation of genes involved in AD and the regulatory responses of these to a known AD risk factor - high cholesterol intake. Unlike rats and mice, guinea pigs possess an Aβ peptide sequence identical to human Aβ. Consistent with the commonality between cardiovascular and AD risk factors in humans, we saw that a high cholesterol diet leads to up-regulation of BACE1 (β-secretase) transcription and down-regulation of ADAM10 (α-secretase) transcription which should increase release of Aβ from APP. Significantly, guinea pigs possess isoforms of AD-related genes found in humans but not present in mice or rats. For example, we discovered that the truncated PS2V isoform of human PSEN2, that is found at raised levels in AD brains and that increases γ-secretase activity and Aβ synthesis, is not uniquely human or aberrant as previously believed. We show that PS2V formation is up-regulated by hypoxia and a high-cholesterol diet while, consistent with observations in humans, Aβ concentrations are raised in some brain regions but not others. Also like humans, but unlike mice, the guinea pig gene encoding tau, MAPT, encodes isoforms with both three and four microtubule binding domains, and cholesterol alters the ratio of these isoforms. We conclude that AD-related genes are highly conserved and more similar to human than the rat or mouse. Guinea pigs represent a superior rodent model for analysis of the impact of dietary factors such as cholesterol on the regulation of AD-related genes.
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Affiliation(s)
- Mathew J. Sharman
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical Sciences, Edith Cowan University, Perth, WA, Australia
- School of Human Life Sciences, University of Tasmania, Launceston, Tasmania, Australia
| | - Seyyed H. Moussavi Nik
- Discipline of Genetics, School of Molecular and Biomedical Science, The University of Adelaide, Adelaide, SA, Australia
| | - Mengqi M. Chen
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical Sciences, Edith Cowan University, Perth, WA, Australia
| | - Daniel Ong
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical Sciences, Edith Cowan University, Perth, WA, Australia
| | - Linda Wijaya
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical Sciences, Edith Cowan University, Perth, WA, Australia
| | - Simon M. Laws
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical Sciences, Edith Cowan University, Perth, WA, Australia
| | - Kevin Taddei
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical Sciences, Edith Cowan University, Perth, WA, Australia
- Sir James McCusker Alzheimer’s Disease Research Unit, Hollywood Private Hospital, Nedlands, WA, Australia
- School of Psychiatry and Clinical Neurosciences, University of Western Australia, Crawley, WA, Australia
| | - Morgan Newman
- Discipline of Genetics, School of Molecular and Biomedical Science, The University of Adelaide, Adelaide, SA, Australia
| | - Michael Lardelli
- Discipline of Genetics, School of Molecular and Biomedical Science, The University of Adelaide, Adelaide, SA, Australia
| | - Ralph N. Martins
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical Sciences, Edith Cowan University, Perth, WA, Australia
- Sir James McCusker Alzheimer’s Disease Research Unit, Hollywood Private Hospital, Nedlands, WA, Australia
- School of Psychiatry and Clinical Neurosciences, University of Western Australia, Crawley, WA, Australia
| | - Giuseppe Verdile
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical Sciences, Edith Cowan University, Perth, WA, Australia
- Sir James McCusker Alzheimer’s Disease Research Unit, Hollywood Private Hospital, Nedlands, WA, Australia
- School of Psychiatry and Clinical Neurosciences, University of Western Australia, Crawley, WA, Australia
- * E-mail:
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8
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Schedin-Weiss S, Inoue M, Teranishi Y, Yamamoto NG, Karlström H, Winblad B, Tjernberg LO. Visualizing active enzyme complexes using a photoreactive inhibitor for proximity ligation--application on γ-secretase. PLoS One 2013; 8:e63962. [PMID: 23717518 PMCID: PMC3663845 DOI: 10.1371/journal.pone.0063962] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 04/09/2013] [Indexed: 11/20/2022] Open
Abstract
Here, we present a highly sensitive method to study protein-protein interactions and subcellular location selectively for active multicomponent enzymes. We apply the method on γ-secretase, the enzyme complex that catalyzes the cleavage of the amyloid precursor protein (APP) to generate amyloid β-peptide (Aβ), the major causative agent in Alzheimer disease (AD). The novel assay is based on proximity ligation, which can be used to study protein interactions in situ with very high sensitivity. In traditional proximity ligation assay (PLA), primary antibody recognition is typically accompanied by oligonucleotide-conjugated secondary antibodies as detection probes. Here, we first performed PLA experiments using antibodies against the γ-secretase components presenilin 1 (PS1), containing the catalytic site residues, and nicastrin, suggested to be involved in substrate recognition. To selectively study the interactions of active γ-secretase, we replaced one of the primary antibodies with a photoreactive γ-secretase inhibitor containing a PEG linker and a biotin group (GTB), and used oligonucleotide-conjugated streptavidin as a probe. Interestingly, significantly fewer interactions were detected with the latter, novel, assay, which is a reasonable finding considering that a substantial portion of PS1 is inactive. In addition, the PLA signals were located more peripherally when GTB was used instead of a PS1 antibody, suggesting that γ-secretase matures distal from the perinuclear ER region. This novel technique thus enables highly sensitive protein interaction studies, determines the subcellular location of the interactions, and differentiates between active and inactive γ-secretase in intact cells. We suggest that similar PLA assays using enzyme inhibitors could be useful also for other enzyme interaction studies.
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Affiliation(s)
- Sophia Schedin-Weiss
- KI-Alzheimer Disease Research Center-KI-ADRC, Karolinska Institutet, Department of Neurobiology, Care Sciences and Society-NVS, Novum Level 5, Stockholm, Sweden.
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9
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Hedskog L, Petersen CAH, Svensson AI, Welander H, Tjernberg LO, Karlström H, Ankarcrona M. γ-Secretase complexes containing caspase-cleaved presenilin-1 increase intracellular Aβ(42) /Aβ(40) ratio. J Cell Mol Med 2012; 15:2150-63. [PMID: 21054783 PMCID: PMC4394225 DOI: 10.1111/j.1582-4934.2010.01208.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Markers for caspase activation and apoptosis have been shown in brains of Alzheimer's disease (AD) patients and AD-mouse models. In neurons, caspase activation is associated with elevated amyloid β-peptide (Aβ) production. Caspases cleave numerous substrates including presenilin-1 (PS1). The cleavage takes place in the large cytosolic loop of PS1-C-terminal fragment (PS1CTF), generating a truncated PS1CTF lacking half of the loop domain (caspCTF). The loop has been shown to possess important regulatory functions with regard to Aβ(40) and Aβ(42) production. Previously, we have demonstrated that γ-secretase complexes are active during apoptosis regardless of caspase cleavage in the PS1CTF-loop. Here, a PS1/PS2-knockout mouse blastocyst-derived cell line was used to establish stable or transient cell lines expressing either caspCTF or full-length CTF (wtCTF). We show that caspCTF restores γ-secretase activity and forms active γ-secretase complexes together with Nicastrin, Pen-2, Aph-1 and PS1-N-terminal fragment. Further, caspCTF containing γ-secretase complexes have a sustained capacity to cleave amyloid precursor protein (APP) and Notch, generating APP and Notch intracellular domain, respectively. However, when compared to wtCTF cells, caspCTF cells exhibit increased intracellular production of Aβ(42) accompanied by increased intracellular Aβ(42) /Aβ(40) ratio without changing the Aβ secretion pattern. Similarly, induction of apoptosis in wtCTF cells generate a similar shift in intracellular Aβ pattern with increased Aβ(42) /Aβ(40) ratio. In summary, we show that caspase cleavage of PS1 generates a γ-secretase complex that increases the intracellular Aβ(42) /Aβ(40) ratio. This can have implications for AD pathogenesis and suggests caspase inhibitors as potential therapeutic agents.
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Affiliation(s)
- Louise Hedskog
- KI-Alzheimer's Disease Research Center, Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Stockholm, Sweden
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10
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Pamrén A, Wanngren J, Tjernberg LO, Winblad B, Bhat R, Näslund J, Karlström H. Mutations in nicastrin protein differentially affect amyloid beta-peptide production and Notch protein processing. J Biol Chem 2011; 286:31153-8. [PMID: 21768095 DOI: 10.1074/jbc.c111.235267] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The γ-secretase complex is responsible for intramembrane processing of over 60 substrates and is involved in Notch signaling as well as in the generation of the amyloid β-peptide (Aβ). Aggregated forms of Aβ have a pathogenic role in Alzheimer disease and, thus, reducing the Aβ levels by inhibiting γ-secretase is a possible treatment strategy for Alzheimer disease. Regrettably, clinical trials have shown that inhibition of γ-secretase results in Notch-related side effects. Therefore, it is of great importance to find ways to inhibit amyloid precursor protein (APP) processing without disturbing vital signaling pathways such as Notch. Nicastrin (Nct) is part of the γ-secretase complex and has been proposed to be involved in substrate recognition and selection. We have investigated how the four evenly spaced and conserved cysteine residues in the Nct ectodomain affect APP and Notch processing. We mutated these cysteines to serines and analyzed them in cells lacking endogenous Nct. We found that two mutants, C213S (C2) and C230S (C3), differentially affected APP and Notch processing. Both the formation of Aβ and the intracellular domain of amyloid precursor protein (AICD) were reduced, whereas the production of Notch intracellular domain (NICD) was maintained on a high level, although C230S (C3) showed impaired complex assembly. Our data demonstrate that single residues in a γ-secretase component besides presenilin are able to differentially affect APP and Notch processing.
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Affiliation(s)
- Annelie Pamrén
- Department of Neurobiology, Caring Sciences and Society, Karolinska Institutet-Alzheimer Disease Research Center, Karolinska Institutet, Novum, SE-141 86 Stockholm, Sweden
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11
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Obulesu M, Somashekhar R, Venu R. Genetics of Alzheimer's Disease: An Insight Into Presenilins and Apolipoprotein E Instigated Neurodegeneration. Int J Neurosci 2011; 121:229-36. [DOI: 10.3109/00207454.2010.551432] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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12
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Gong P, Vetrivel KS, Nguyen PD, Meckler X, Cheng H, Kounnas MZ, Wagner SL, Parent AT, Thinakaran G. Mutation analysis of the presenilin 1 N-terminal domain reveals a broad spectrum of gamma-secretase activity toward amyloid precursor protein and other substrates. J Biol Chem 2010; 285:38042-52. [PMID: 20921220 DOI: 10.1074/jbc.m110.132613] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The γ-secretase protein complex executes the intramembrane proteolysis of amyloid precursor protein (APP), which releases Alzheimer disease β-amyloid peptide. In addition to APP, γ-secretase also cleaves several other type I membrane protein substrates including Notch1 and N-cadherin. γ-Secretase is made of four integral transmembrane protein subunits: presenilin (PS), nicastrin, APH1, and PEN2. Multiple lines of evidence indicate that a heteromer of PS-derived N- and C-terminal fragments functions as the catalytic subunit of γ-secretase. Only limited information is available on the domains within each subunit involved in the recognition and recruitment of diverse substrates and the transfer of substrates to the catalytic site. Here, we performed mutagenesis of two domains of PS1, namely the first luminal loop domain (LL1) and the second transmembrane domain (TM2), and analyzed PS1 endoproteolysis as well as the catalytic activities of PS1 toward APP, Notch, and N-cadherin. Our results show that distinct residues within LL1 and TM2 domains as well as the length of the LL1 domain are critical for PS1 endoproteolysis, but not for PS1 complex formation with nicastrin, APH1, and PEN2. Furthermore, our experimental PS1 mutants formed γ-secretase complexes with distinct catalytic properties toward the three substrates examined in this study; however, the mutations did not affect PS1 interaction with the substrates. We conclude that the N-terminal LL1 and TM2 domains are critical for PS1 endoproteolysis and the coordination between the putative substrate-docking site and the catalytic core of the γ-secretase.
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Affiliation(s)
- Ping Gong
- Department of Neurobiology, University of Chicago, Chicago, Illinois 60637, USA
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13
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Behbahani H, Pavlov PF, Wiehager B, Nishimura T, Winblad B, Ankarcrona M. Association of Omi/HtrA2 with γ-secretase in mitochondria. Neurochem Int 2010; 57:668-75. [PMID: 20705111 DOI: 10.1016/j.neuint.2010.08.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Accepted: 08/03/2010] [Indexed: 01/27/2023]
Abstract
Omi/HtrA2, a mitochondrial serine protease with chaperone activity, is involved in varied intracellular processes. Dysfunctional Omi/HtrA2 has thus been implicated in various neurodegenerative disorders. Previously, we have shown that γ-secretase complexes are present and active in mitochondria. Here, we demonstrate that peptide corresponding to C-terminus of presenilin-1, as previously reported to activate Omi/HtrA2, interacts with Omi/HtrA2 in isolated mitochondria. Moreover, we show that Omi/HtrA2 interacts with presenilin in active γ-secretase complexes located to mitochondria. Using a biotinylated γ-secretase inhibitor and confocal microscopy, we could further confirm the association of γ-secretase complexes with mitochondrial Omi/HtrA2. Furthermore, determination of γ-secretase complex topology in isolated mitochondria revealed an association of γ-secretase complexes with the outer membrane of mitochondria with the extreme PS1 C-terminus facing the inter-membrane space. We have also studied the impact of Omi/HtrA2 on γ-secretase activity, measuring APP intracellular domain (AICD) production. We found reduced AICD production in mitochondria isolated from Omi/HtrA2 knockout mouse embryonic fibroblasts, indicating a significant role of Omi/HtrA2 on γ-secretase activity. Thus, our results provide information for understanding the interplay between mitochondrial Omi/HtrA2 and γ-secretase complexes in AD.
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Affiliation(s)
- Homira Behbahani
- Karolinska Institutet and Dainippon Sumitomo Pharma Alzheimer Center (KASPAC), Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Huddinge, Sweden.
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