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Alsaqati M, Thomas RS, Kidd EJ. Upregulation of endocytic protein expression in the Alzheimer's disease male human brain. AGING BRAIN 2023; 4:100084. [PMID: 37449017 PMCID: PMC10336166 DOI: 10.1016/j.nbas.2023.100084] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 06/14/2023] [Accepted: 06/16/2023] [Indexed: 07/18/2023] Open
Abstract
Amyloid-beta (Aβ) is produced from amyloid precursor protein (APP) primarily after APP is internalised by endocytosis and clathrin-mediated endocytic processes are altered in Alzheimer's disease (AD). There is also evidence that cholesterol and flotillin affect APP endocytosis. We hypothesised that endocytic protein expression would be altered in the brains of people with AD compared to non-diseased subjects which could be linked to increased Aβ generation. We compared protein expression in frontal cortex samples from men with AD compared to age-matched, non-diseased controls. Soluble and insoluble Aβ40 and Aβ42, the soluble Aβ42/Aβ40 ratio, βCTF, BACE1, presenilin-1 and the ratio of phosphorylated:total GSK3β were significantly increased while the insoluble Aβ42:Aβ40 ratio was significantly decreased in AD brains. Total and phosphorylated tau were markedly increased in AD brains. Significant increases in clathrin, AP2, PICALM isoform 4, Rab-5 and caveolin-1 and 2 were seen in AD brains but BIN1 was decreased. However, using immunohistochemistry, caveolin-1 and 2 were decreased. The results obtained here suggest an overall increase in endocytosis in the AD brain, explaining, at least in part, the increased production of Aβ during AD.
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Affiliation(s)
| | | | - Emma J. Kidd
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff CF10 3NB, UK
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2
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Sparks RP, Arango AS, Jenkins JL, Guida WC, Tajkhorshid E, Sparks CE, Sparks JD, Fratti RA. An Allosteric Binding Site on Sortilin Regulates the Trafficking of VLDL, PCSK9, and LDLR in Hepatocytes. Biochemistry 2020; 59:4321-4335. [PMID: 33153264 DOI: 10.1021/acs.biochem.0c00741] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
ApoB lipoproteins (apo B-Lp) are produced in hepatocytes, and their secretion requires the cargo receptor sortilin. We examined the secretion of apo B-Lp-containing very low-density lipoprotein (VLDL), an LDL progenitor. Sortilin also regulates the trafficking of the subtilase PCSK9, which when secreted binds the LDL receptor (LDLR), resulting in its endocytosis and destruction at the lysosome. We show that the site 2 binding compound (cpd984) has multiple effects in hepatocytes, including (1) enhanced Apo-Lp secretion, (2) increased cellular PCSK9 retention, and (3) augmented levels of LDLR at the plasma membrane. We postulate that cpd984 enhances apo B-Lp secretion in part through binding the lipid phosphatidylinositol 3,4,5-trisphosphate (PIP3), which is present at higher levels on circulating VLDL form fed rats relative to after fasting. We attribute the enhanced VLDL secretion to its increased binding affinity for sortilin site 1 induced by cpd984 binding site 2. This hinders PCSK9 binding and secretion, which would subsequently prevent its binding to LDLR leading to its degradation. This suggests that site 2 is an allosteric regulator of site 1 binding. This effect is not limited to VLDL, as cpd984 augments binding of the neuropeptide neurotensin (NT) to sortilin site 1. Molecular dynamics simulations demonstrate that the C-terminus of NT (Ct-NT) stably binds site 1 through an electrostatic interaction. This was bolstered by the ability of Ct-NT to disrupt lower-affinity interactions between sortilin and the site 1 ligand PIP3. Together, these data show that binding cargo at sortilin site 1 is allosterically regulated through site 2 binding, with important ramifications for cellular lipid homeostasis involving proteins such as PCSK9 and LDLR.
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Affiliation(s)
- Robert P Sparks
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Andres S Arango
- Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Jermaine L Jenkins
- Structural Biology & Biophysics Facility, University of Rochester Medical Center, Rochester, New York 14642, United States
| | - Wayne C Guida
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
| | - Emad Tajkhorshid
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States.,Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States.,Beckman Institute for Advanced Science & Technology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Charles E Sparks
- Department of Pathology & Laboratory Medicine, University of Rochester Medical Center, Rochester, New York 14642, United States
| | - Janet D Sparks
- Department of Pathology & Laboratory Medicine, University of Rochester Medical Center, Rochester, New York 14642, United States
| | - Rutilio A Fratti
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States.,Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
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3
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Medoro A, Bartollino S, Mignogna D, Passarella D, Porcile C, Pagano A, Florio T, Nizzari M, Guerra G, Di Marco R, Intrieri M, Raimo G, Russo C. Complexity and Selectivity of γ-Secretase Cleavage on Multiple Substrates: Consequences in Alzheimer's Disease and Cancer. J Alzheimers Dis 2018; 61:1-15. [PMID: 29103038 DOI: 10.3233/jad-170628] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The processing of the amyloid-β protein precursor (AβPP) by β- and γ-secretases is a pivotal event in the genesis of Alzheimer's disease (AD). Besides familial mutations on the AβPP gene, or upon its overexpression, familial forms of AD are often caused by mutations or deletions in presenilin 1 (PSEN1) and 2 (PSEN2) genes: the catalytic components of the proteolytic enzyme γ-secretase (GS). The "amyloid hypothesis", modified over time, states that the aberrant processing of AβPP by GS induces the formation of specific neurotoxic soluble amyloid-β (Aβ) peptides which, in turn, cause neurodegeneration. This theory, however, has recently evidenced significant limitations and, in particular, the following issues are debated: 1) the concept and significance of presenilin's "gain of function" versus "loss of function"; and 2) the presence of several and various GS substrates, which interact with AβPP and may influence Aβ formation. The latter consideration is suggestive: despite the increasing number of GS substrates so far identified, their reciprocal interaction with AβPP itself, even in the AD field, is significantly unexplored. On the other hand, GS is also an important pharmacological target in the cancer field; inhibitors or GS activity are investigated in clinical trials for treating different tumors. Furthermore, the function of AβPP and PSENs in brain development and in neuronal migration is well known. In this review, we focused on a specific subset of GS substrates that directly interact with AβPP and are involved in its proteolysis and signaling, by evaluating their role in neurodegeneration and in cell motility or proliferation, as a possible connection between AD and cancer.
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Affiliation(s)
- Alessandro Medoro
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Silvia Bartollino
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Donatella Mignogna
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Daniela Passarella
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Carola Porcile
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Aldo Pagano
- Department of Experimental Medicine, University of Genoa and Ospedale Policlinico San Martino, IRCCS per l'Oncologia, Genoa, Italy
| | - Tullio Florio
- Department of Internal Medicine and Centre of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
| | - Mario Nizzari
- Department of Internal Medicine and Centre of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
| | - Germano Guerra
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Roberto Di Marco
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Mariano Intrieri
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Gennaro Raimo
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Claudio Russo
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
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4
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Blechingberg J, Poulsen ASA, Kjølby M, Monti G, Allen M, Ivarsen AK, Lincoln SJ, Thotakura G, Vægter CB, Ertekin-Taner N, Nykjær A, Andersen OM. An alternative transcript of the Alzheimer's disease risk gene SORL1 encodes a truncated receptor. Neurobiol Aging 2018; 71:266.e11-266.e24. [PMID: 30078640 DOI: 10.1016/j.neurobiolaging.2018.06.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 06/03/2018] [Accepted: 06/18/2018] [Indexed: 10/28/2022]
Abstract
SORL1 encodes a 250-kDa protein named sorLA, a functional sorting receptor for the amyloid precursor protein (APP). Several single nucleotide polymorphisms of the gene SORL1, encoding sorLA, are genetically associated with Alzheimer's disease (AD). In the existing literature, SORL1 is insufficiently described at the transcriptional level, and there is very limited amount of functional data defining different transcripts. We have characterized a SORL1 transcript containing a novel exon 30B. The transcript is expressed in most brain regions with highest expression in the temporal lobe and hippocampus. Exon 30B is spliced to exon 31, leading to a mature transcript that encodes an 829 amino acid sorLA receptor. This receptor variant lacks the binding site for APP and is unlikely to function in APP sorting. This transcript is expressed in equal amounts in the cerebellum from AD and non-AD individuals. Our data describe a transcript that encodes a truncated sorLA receptor, suggesting novel neuronal functions for sorLA and that alternative transcription provides a mechanism for SORL1 activity regulation.
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Affiliation(s)
- Jenny Blechingberg
- Danish Research Institute of Translational Neuroscience (DANDRITE) Nordic-EMBL Partnership, Aarhus, Denmark
| | | | - Mads Kjølby
- Danish Research Institute of Translational Neuroscience (DANDRITE) Nordic-EMBL Partnership, Aarhus, Denmark; Danish Diabetes Academy, Novo Nordisk Foundation, Aarhus University, Aarhus, Denmark
| | - Giulia Monti
- Danish Research Institute of Translational Neuroscience (DANDRITE) Nordic-EMBL Partnership, Aarhus, Denmark
| | - Mariet Allen
- Department of Neuroscience, Mayo Clinic, FL, USA
| | - Anne Kathrine Ivarsen
- Danish Research Institute of Translational Neuroscience (DANDRITE) Nordic-EMBL Partnership, Aarhus, Denmark
| | | | | | - Christian B Vægter
- Danish Research Institute of Translational Neuroscience (DANDRITE) Nordic-EMBL Partnership, Aarhus, Denmark
| | | | - Anders Nykjær
- Danish Research Institute of Translational Neuroscience (DANDRITE) Nordic-EMBL Partnership, Aarhus, Denmark; The Lundbeck Foundation Research Center MIND, Aarhus, Denmark; The Danish Research Foundation Center PROMEMO, Department of Biomedicine, Aarhus, Denmark; Department of Neurosurgery, Aarhus University Hospital, Aarhus, Denmark
| | - Olav M Andersen
- Danish Research Institute of Translational Neuroscience (DANDRITE) Nordic-EMBL Partnership, Aarhus, Denmark.
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5
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Uchiyama K, Tomita M, Yano M, Chida J, Hara H, Das NR, Nykjaer A, Sakaguchi S. Prions amplify through degradation of the VPS10P sorting receptor sortilin. PLoS Pathog 2017; 13:e1006470. [PMID: 28665987 PMCID: PMC5509376 DOI: 10.1371/journal.ppat.1006470] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Revised: 07/13/2017] [Accepted: 06/14/2017] [Indexed: 01/09/2023] Open
Abstract
Prion diseases are a group of fatal neurodegenerative disorders caused by prions, which consist mainly of the abnormally folded isoform of prion protein, PrPSc. A pivotal pathogenic event in prion disease is progressive accumulation of prions, or PrPSc, in brains through constitutive conformational conversion of the cellular prion protein, PrPC, into PrPSc. However, the cellular mechanism by which PrPSc is progressively accumulated in prion-infected neurons remains unknown. Here, we show that PrPSc is progressively accumulated in prion-infected cells through degradation of the VPS10P sorting receptor sortilin. We first show that sortilin interacts with PrPC and PrPSc and sorts them to lysosomes for degradation. Consistently, sortilin-knockdown increased PrPSc accumulation in prion-infected cells. In contrast, overexpression of sortilin reduced PrPSc accumulation in prion-infected cells. These results indicate that sortilin negatively regulates PrPSc accumulation in prion-infected cells. The negative role of sortilin in PrPSc accumulation was further confirmed in sortilin-knockout mice infected with prions. The infected mice had accelerated prion disease with early accumulation of PrPSc in their brains. Interestingly, sortilin was reduced in prion-infected cells and mouse brains. Treatment of prion-infected cells with lysosomal inhibitors, but not proteasomal inhibitors, increased the levels of sortilin. Moreover, sortilin was reduced following PrPSc becoming detectable in cells after infection with prions. These results indicate that PrPSc accumulation stimulates sortilin degradation in lysosomes. Taken together, these results show that PrPSc accumulation of itself could impair the sortilin-mediated sorting of PrPC and PrPSc to lysosomes for degradation by stimulating lysosomal degradation of sortilin, eventually leading to progressive accumulation of PrPSc in prion-infected cells. Once prions consisting mainly of PrPSc infect hosts, they constitutively propagate in their brains. Progressive production of PrPSc through the constitutive conformational conversion of PrPC into PrPSc underlies prion propagation. However, the mechanism enabling progressive production of PrPSc in prion-infected cells remains unknown. We here found that the VPS10P sorting receptor sortilin is involved in degradation of PrPC and PrPSc in infected cells by binding to both molecules and subsequently trafficking them to the lysosomal protein degradation pathway. Interestingly, we also found that degradation of sortilin was stimulated in lysosomes in prion-infected cells possibly as a result of the sortilin-PrPC or -PrPSc complexes being trafficked to lysosomes. Our findings indicate that PrPSc itself impairs the sortilin-mediated degradation of PrPC and PrPSc by stimulating degradation of sortilin in lysosomes. This eventually results in progressive production of PrPSc in prion-infected cells by increasing the opportunity of PrPC to convert into PrPSc and by accumulating the already produced PrPSc. This mechanism was confirmed in sortilin-KO mice infected with prions. The mice had exacerbated prion disease with earlier accumulation of PrPSc in their brains.
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Affiliation(s)
- Keiji Uchiyama
- Division of Molecular Neurobiology, Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
- * E-mail: (SS); (KU)
| | - Mitsuru Tomita
- Division of Molecular Neurobiology, Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
- Student Laboratory, Faculty of Medicine, Tokushima University, Tokushima, Japan
| | - Masashi Yano
- Division of Molecular Neurobiology, Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
| | - Junji Chida
- Division of Molecular Neurobiology, Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
| | - Hideyuki Hara
- Division of Molecular Neurobiology, Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
| | - Nandita Rani Das
- Division of Molecular Neurobiology, Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
| | - Anders Nykjaer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Suehiro Sakaguchi
- Division of Molecular Neurobiology, Institute for Enzyme Research (KOSOKEN), Tokushima University, Tokushima, Japan
- * E-mail: (SS); (KU)
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6
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Piscopo P, Tosto G, Belli C, Talarico G, Galimberti D, Gasparini M, Canevelli M, Poleggi A, Crestini A, Albani D, Forloni G, Lucca U, Quadri P, Tettamanti M, Fenoglio C, Scarpini E, Bruno G, Vanacore N, Confaloni A. SORL1 Gene is Associated with the Conversion from Mild Cognitive Impairment to Alzheimer's Disease. J Alzheimers Dis 2016; 46:771-6. [PMID: 25881907 DOI: 10.3233/jad-141551] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Several studies have established the sortilin-related receptor gene (SORL1) as a susceptibility locus for Alzheimer's disease (AD). Single nucleotide polymorphisms of SORL1 reported in literature as being associated with AD were investigated in an Italian case-control data set, and their role as a risk factor of conversion to AD was studied in an independent sample of subjects diagnosed with mild cognitive impairment (MCI) at baseline. rs641120, rs2070045, and rs1010159 were genotyped in 734 subjects diagnosed with AD (n = 338) and MCI (n = 181) and in healthy controls (n = 215). Our results confirmed the association between rs641120 and AD (p = 0.01). In the MCI cohort, rs1010159 was associated with conversion to AD (HR = 1.56, p = 0.002). Taken together, these findings confirm that SORL1 is associated with AD and might be a potential tool for identifying MCI subjects at high risk of conversion to AD.
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Affiliation(s)
- Paola Piscopo
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy
| | - Giuseppe Tosto
- Memory Clinic, Department of Neurology and Psychiatry, University of Rome "Sapienza", Italy
| | - Chiara Belli
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy
| | - Giuseppina Talarico
- Memory Clinic, Department of Neurology and Psychiatry, University of Rome "Sapienza", Italy
| | - Daniela Galimberti
- Department of Pathophysiology and Transplantation, "Dino Ferrari" Center, University of Milan, Fondazione Cà Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy
| | - Marina Gasparini
- Memory Clinic, Department of Neurology and Psychiatry, University of Rome "Sapienza", Italy
| | - Marco Canevelli
- Memory Clinic, Department of Neurology and Psychiatry, University of Rome "Sapienza", Italy
| | - Anna Poleggi
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy
| | - Alessio Crestini
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy
| | - Diego Albani
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Gianluigi Forloni
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Ugo Lucca
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Pierluigi Quadri
- Geriatric Division, Ospedali Regionali of Lugano and Mendrisio, Switzerland
| | - Mauro Tettamanti
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Chiara Fenoglio
- Department of Pathophysiology and Transplantation, "Dino Ferrari" Center, University of Milan, Fondazione Cà Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy
| | - Elio Scarpini
- Department of Pathophysiology and Transplantation, "Dino Ferrari" Center, University of Milan, Fondazione Cà Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy
| | - Giuseppe Bruno
- Memory Clinic, Department of Neurology and Psychiatry, University of Rome "Sapienza", Italy
| | - Nicola Vanacore
- Department of National Centre of Epidemiology, Surveillance and Health Promotion, Istituto Superiore di Sanità, Rome, Italy
| | - Annamaria Confaloni
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy
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Huang CC, Liu ME, Kao HW, Chou KH, Yang AC, Wang YH, Chen TR, Tsai SJ, Lin CP. Effect of Alzheimer's Disease Risk Variant rs3824968 at SORL1 on Regional Gray Matter Volume and Age-Related Interaction in Adult Lifespan. Sci Rep 2016; 6:23362. [PMID: 26996954 PMCID: PMC4800313 DOI: 10.1038/srep23362] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 03/01/2016] [Indexed: 11/09/2022] Open
Abstract
Sortilin receptor 1 (SORL1) is involved in cellular trafficking of amyloid precursor protein and plays an essential role in amyloid-beta peptide generation in Alzheimer disease (AD). The major A allele in a SORL1 single nucleotide polymorphism (SNP), rs3824968, is associated with an increased AD risk. However, the role of SORL1 rs3824968 in the normal ageing process has rarely been examined in relation to brain structural morphology. This study investigated the association between SORL1 rs3824968 and grey matter (GM) volume in a nondemented Chinese population of 318 adults within a wide age range (21-92 years). Through voxel-based morphometry, we found that participants carrying SORL1 allele A exhibited significantly smaller GM volumes in the right posterior cingulate, left middle occipital, medial frontal, and superior temporal gyri. Considerable interaction between age and SORL1 suggested a detrimental and accelerated ageing effect of allele A on putamen. These findings provide evidence that SORL1 rs3824968 modulates regional GM volume and is associated with brain trajectory during the adult lifespan.
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Affiliation(s)
- Chu-Chung Huang
- Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Mu-En Liu
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Hung-Wen Kao
- Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.,Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Kun-Hsien Chou
- Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Albert C Yang
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan.,Center for Dynamical Biomarkers and Translational Medicine, National Central University, Chungli, Taiwan
| | - Ying-Hsiu Wang
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Tong-Ru Chen
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Shih-Jen Tsai
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Ching-Po Lin
- Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan.,Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan
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8
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Zetzsche T, Rujescu D, Hardy J, Hampel H. Advances and perspectives from genetic research: development of biological markers in Alzheimer’s disease. Expert Rev Mol Diagn 2014; 10:667-90. [PMID: 20629514 DOI: 10.1586/erm.10.48] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Thomas Zetzsche
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilian-University, Nussbaumstrasse 7, Munich, Germany. thomas.zetzsche@ med.uni-muenchen.de
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9
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Wen YY, Wang XX, Pei DS, Zheng JN. p21-Activated kinase 5: a pleiotropic kinase. Bioorg Med Chem Lett 2013; 23:6636-9. [PMID: 24215894 DOI: 10.1016/j.bmcl.2013.10.051] [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: 08/14/2013] [Revised: 10/08/2013] [Accepted: 10/23/2013] [Indexed: 02/03/2023]
Abstract
The PAKs (p21-activated kinases) are highly conserved serine/threonine protein kinases which comprise six mammalian PAKs. PAK5 (p21-activated kinase 5) is the least understood member of PAKs that regulate many intracellular processes when they are stimulated by activated forms of the small GTPases Cdc42 and Rac. PAK5 takes an important part in multiple signal pathways in mammalian cells and controls a variety of cellular functions including cytoskeleton organization, cell motility and apoptosis. The main goal of this review is to describe the structure, mechanisms underlying its activity regulation, its role in apoptosis and the likely directions of further research.
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Affiliation(s)
- Yi-Yang Wen
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College, 84 West Huai-hai Road, Xuzhou 221002, Jiangsu, China
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10
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Willnow TE, Andersen OM. Sorting receptor SORLA – a trafficking path to avoid Alzheimer disease. J Cell Sci 2013; 126:2751-60. [DOI: 10.1242/jcs.125393] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Excessive proteolytic breakdown of the amyloid precursor protein (APP) to neurotoxic amyloid β peptides (Aβ) by secretases in the brain is a molecular cause of Alzheimer disease (AD). According to current concepts, the complex route whereby APP moves between the secretory compartment, the cell surface and endosomes to encounter the various secretases determines its processing fate. However, the molecular mechanisms that control the intracellular trafficking of APP in neurons and their contribution to AD remain poorly understood. Here, we describe the functional elucidation of a new sorting receptor SORLA that emerges as a central regulator of trafficking and processing of APP. SORLA interacts with distinct sets of cytosolic adaptors for anterograde and retrograde movement of APP between the trans-Golgi network and early endosomes, thereby restricting delivery of the precursor to endocytic compartments that favor amyloidogenic breakdown. Defects in SORLA and its interacting adaptors result in transport defects and enhanced amyloidogenic processing of APP, and represent important risk factors for AD in patients. As discussed here, these findings uncovered a unique regulatory pathway for the control of neuronal protein transport, and provide clues as to why defects in this pathway cause neurodegenerative disease.
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11
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Tsolakidou A, Alexopoulos P, Guo LH, Grimmer T, Westerteicher C, Kratzer M, Jiang M, Bujo H, Roselli F, Leante MR, Livrea P, Kurz A, Perneczky R. β-Site amyloid precursor protein-cleaving enzyme 1 activity is related to cerebrospinal fluid concentrations of sortilin-related receptor with A-type repeats, soluble amyloid precursor protein, and tau. Alzheimers Dement 2012; 9:386-91. [PMID: 23127467 DOI: 10.1016/j.jalz.2012.01.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 12/30/2011] [Accepted: 01/24/2012] [Indexed: 11/26/2022]
Abstract
BACKGROUND β-Site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1) activity determines the rate of APP cleavage and is therefore the main driver of amyloid β production, which is a pathological hallmark of Alzheimer's disease (AD). METHODS The present study explored the correlation between BACE1 activity and cerebrospinal fluid (CSF) markers of APP metabolism and axonal degeneration in 63 patients with mild AD and 12 healthy control subjects. RESULTS In the AD group, positive correlations between BACE1 activity and soluble APP β, the APP sorting receptor sortilin-related receptor with A-type repeats (also known as SorLA or LR11), and tau were detected. BACE1 activity was not associated with amyloid β1-42 or soluble APP α concentrations in the AD group, and no associations between BACE1 activity and any of the protein concentrations were found in the control group. CONCLUSION Our results confirm the relevance of BACE1 and sortilin-related receptor with A-type repeats within the amyloid cascade and also provide a further piece of evidence for the link between amyloid and tau pathology in AD.
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Affiliation(s)
- Amalia Tsolakidou
- Department of Psychiatry and Psychotherapy, Klinikum rechts der Isar, Technische Universität München, München, Germany
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Lukiw WJ. Amyloid beta (Aβ) peptide modulators and other current treatment strategies for Alzheimer's disease (AD). Expert Opin Emerg Drugs 2012; 17:10.1517/14728214.2012.672559. [PMID: 22439907 PMCID: PMC3399957 DOI: 10.1517/14728214.2012.672559] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Introduction: Alzheimer's disease (AD) is a common, progressive neurological disorder whose incidence is reaching epidemic proportions. The prevailing "amyloid cascade hypothesis," which maintains that the aberrant proteolysis of beta-amyloid precursor protein (βAPP) into neurotoxic amyloid beta (Aβ) peptides is central to the etiopathology of AD, continues to dominate pharmacological approaches to the clinical management of this insidious disorder. This review is a compilation and update on current pharmacological strategies designed to down-regulate Aβ42 peptide generation in an effort to ameliorate the tragedy of AD. Areas covered: This review utilized online data searches at various open online-access websites including the Alzheimer Association, Alzheimer Research Forum; individual drug company databases; the National Institutes of Health (NIH) Medline; Pharmaprojects database; Scopus; inter-University research communications; and unpublished research data. Expert opinion: Anti-acetylcholinesterase-, chelation-, N-methyl-D-aspartate (NMDA) receptor antagonist-, statin-, Aβ immunization-, β-secretase-, γ-secretase-based, and other strategies to modulate βAPP processing, have dominated pharmacological approaches directed against AD-type neurodegenerative pathology. Cumulative clinical results of these efforts remain extremely disappointing, and have had little overall impact on the clinical management of AD. While a number of novel approaches are in consideration and development, to date there is still no effective treatment or cure for this expanding healthcare concern.
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Affiliation(s)
- Walter J Lukiw
- Louisiana State University Health Sciences Center, LSU Neuroscience Center of Excellence, Ophthalmology and Human Genetics, , 2020 Gravier Street, Suite 904, New Orleans LA 70112-2272 , USA +1 504 599 0842 ; +1 504 568 5801 ;
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Bazan NG, Molina MF, Gordon WC. Docosahexaenoic acid signalolipidomics in nutrition: significance in aging, neuroinflammation, macular degeneration, Alzheimer's, and other neurodegenerative diseases. Annu Rev Nutr 2011; 31:321-51. [PMID: 21756134 DOI: 10.1146/annurev.nutr.012809.104635] [Citation(s) in RCA: 302] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Essential polyunsaturated fatty acids (PUFAs) are critical nutritional lipids that must be obtained from the diet to sustain homeostasis. Omega-3 and -6 PUFAs are key components of biomembranes and play important roles in cell integrity, development, maintenance, and function. The essential omega-3 fatty acid family member docosahexaenoic acid (DHA) is avidly retained and uniquely concentrated in the nervous system, particularly in photoreceptors and synaptic membranes. DHA plays a key role in vision, neuroprotection, successful aging, memory, and other functions. In addition, DHA displays anti-inflammatory and inflammatory resolving properties in contrast to the proinflammatory actions of several members of the omega-6 PUFAs family. This review discusses DHA signalolipidomics, comprising the cellular/tissue organization of DHA uptake, its distribution among cellular compartments, the organization and function of membrane domains rich in DHA-containing phospholipids, and the cellular and molecular events revealed by the uncovering of signaling pathways regulated by DHA and docosanoids, the DHA-derived bioactive lipids, which include neuroprotectin D1 (NPD1), a novel DHA-derived stereoselective mediator. NPD1 synthesis agonists include neurotrophins and oxidative stress; NPD1 elicits potent anti-inflammatory actions and prohomeostatic bioactivity, is anti-angiogenic, promotes corneal nerve regeneration, and induces cell survival. In the context of DHA signalolipidomics, this review highlights aging and the evolving studies on the significance of DHA in Alzheimer's disease, macular degeneration, Parkinson's disease, and other brain disorders. DHA signalolipidomics in the nervous system offers emerging targets for pharmaceutical intervention and clinical translation.
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Affiliation(s)
- Nicolas G Bazan
- Neuroscience Center of Excellence and Department of Ophthalmology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA.
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Clinical and neurobiological correlates of soluble amyloid precursor proteins in the cerebrospinal fluid. Alzheimers Dement 2011; 8:304-11. [PMID: 22055653 DOI: 10.1016/j.jalz.2011.04.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 03/14/2011] [Accepted: 04/27/2011] [Indexed: 01/30/2023]
Abstract
BACKGROUND According to a widely accepted hypothesis, the amyloid precursor protein (APP) is processed by two competing pathways: the amyloidogenic β-secretase-mediated pathway or the nonamyloidogenic α-secretase-mediated pathway. APP is cleaved preferentially through the nonamyloidogenic pathway in normal brain, whereas the balance shifts to the amyloidogenic pathway in Alzheimer's disease (AD). The levels of the α-secretase-cleaved soluble APP (sAPPα) and β-secretase-cleaved soluble APP (sAPPβ) in cerebrospinal fluid (CSF) are likely to reflect these competing mechanisms. METHODS We investigated the levels and the relationship between sAPPα and sAPPβ in the CSF of 64 patients with mild AD, 76 patients with mild cognitive impairment, and 12 cognitively healthy control subjects, as well as the effect of apolipoprotein E genotype and sex on soluble APP levels. RESULTS There was a significant positive correlation between sAPPα and sAPPβ levels in all three groups. sAPPα and sAPPβ concentrations were higher in patients with mild cognitive impairment compared with patients with AD. In the AD group, females exhibited higher sAPPα and sAPPβ levels than males. No influence of the apolipoprotein E genotype on soluble APP concentrations was detected. DISCUSSION The positive correlation between sAPPα and sAPPβ challenges the hypothesis that AD is caused by an imbalance of the α- and β-secretase APP proteolysis through competing mechanisms. Moreover, the differences in CSF levels of sAPPα and sAPPβ between male and female patients with AD may reflect a "sexual dimorphism" in the activity of the two APP processing pathways in AD.
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Ma SL, Lam LCW. Panel of Genetic Variations as a Potential Non-invasive Biomarker for Early Diagnosis of Alzheimer's Disease. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2011; 9:54-66. [PMID: 23429712 PMCID: PMC3569084 DOI: 10.9758/cpn.2011.9.2.54] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 05/06/2011] [Accepted: 05/23/2011] [Indexed: 01/05/2023]
Abstract
Alzheimer's disease (AD) is the most prevalent form of dementia. Biomarkers such as levels of amyloid beta (Aβ) in cerebrospinal fluid and ApoE genotyping were suggested for the diagnosis of AD, however, the result is either non-conclusive or with invasive procedure. Genome-wide association studies (GWASs) for AD suggested single nucleotide polymorphisms (SNPs) in many genes are associated with the risk of AD, but each only contributed with small effect to the disease. By incorporating a panel of established genetic susceptibility factors, the risk of an individual in getting AD could be better estimated. Further research will be required to reveal if adding to the current well-developed clinical diagnosis protocol, the accuracy and specificity of diagnosis of AD would be greatly improved and if this might also be beneficial in identifying pre-symptomatic AD patients for early diagnosis and intervention of the disease.
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Affiliation(s)
- Suk Ling Ma
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA. ; Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
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Neuroprotectin D1 induces neuronal survival and downregulation of amyloidogenic processing in Alzheimer's disease cellular models. Mol Neurobiol 2011; 43:131-8. [PMID: 21431475 DOI: 10.1007/s12035-011-8174-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 02/25/2011] [Indexed: 01/13/2023]
Abstract
The mediator neuroprotectin D1 (NPD1) is an enzymatic derivative of the omega-3 essential fatty acid docosahexaenoic acid. NPD1 stereoselectively and specifically binds to human retinal pigment epithelium (RPE) cells and neutrophils. In turn, this lipid mediator induces dephosphorylation of Bcl-x(L) in a PP2A-dependent manner and induces PI3K/Akt and mTOR/p70S6K pathways leading to RPE cell survival during oxidative stress-induced apoptosis. As a proof of principle of its systemic in vivo bioactivity, NPD1 attenuates laser-induced choroidal neovascularization in mice. Using human neural cells transfected with amyloid precursor protein (APP)sw (Swedish double mutation APP695sw, K595N, M596L), NPD1 was shown to regulate secretase-mediated production of Aβ peptide, downregulates pro-inflammatory gene expression, and promotes cell survival. In human neural cells overexpressing beta-amyloid precursor protein (βAPP), the lipid mediator suppressed Aβ42 shedding by downregulating β-secretase (BACE1) while activating the α-secretase (ADAM10), thus shifting the βAPP cleavage from the noxious amyloidogenic pathway into a non-amyloidogenic, neurotrophic pathway. Furthermore, downregulation of Aβ42 peptide release by NPD1 may be dependent upon PPARγ activation. In conclusion, NPD1 exhibits anti-inflammatory, anti-amyloidogenic, and anti-apoptotic bioactivities in human neural cells in part via PPARγ signaling and through the targeting of α- and β-secretase systems.
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Zhao Y, Calon F, Julien C, Winkler JW, Petasis NA, Lukiw WJ, Bazan NG. Docosahexaenoic acid-derived neuroprotectin D1 induces neuronal survival via secretase- and PPARγ-mediated mechanisms in Alzheimer's disease models. PLoS One 2011; 6:e15816. [PMID: 21246057 PMCID: PMC3016440 DOI: 10.1371/journal.pone.0015816] [Citation(s) in RCA: 178] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 12/02/2010] [Indexed: 01/22/2023] Open
Abstract
Neuroprotectin D1 (NPD1) is a stereoselective mediator derived from the omega-3 essential fatty acid docosahexaenoic acid (DHA) with potent inflammatory resolving and neuroprotective bioactivity. NPD1 reduces Aβ42 peptide release from aging human brain cells and is severely depleted in Alzheimer's disease (AD) brain. Here we further characterize the mechanism of NPD1's neurogenic actions using 3xTg-AD mouse models and human neuronal-glial (HNG) cells in primary culture, either challenged with Aβ42 oligomeric peptide, or transfected with beta amyloid precursor protein (βAPP)(sw) (Swedish double mutation APP695(sw), K595N-M596L). We also show that NPD1 downregulates Aβ42-triggered expression of the pro-inflammatory enzyme cyclooxygenase-2 (COX-2) and of B-94 (a TNF-α-inducible pro-inflammatory element) and apoptosis in HNG cells. Moreover, NPD1 suppresses Aβ42 peptide shedding by down-regulating β-secretase-1 (BACE1) while activating the α-secretase ADAM10 and up-regulating sAPPα, thus shifting the cleavage of βAPP holoenzyme from an amyloidogenic into the non-amyloidogenic pathway. Use of the thiazolidinedione peroxisome proliferator-activated receptor gamma (PPARγ) agonist rosiglitazone, the irreversible PPARγ antagonist GW9662, and overexpressing PPARγ suggests that the NPD1-mediated down-regulation of BACE1 and Aβ42 peptide release is PPARγ-dependent. In conclusion, NPD1 bioactivity potently down regulates inflammatory signaling, amyloidogenic APP cleavage and apoptosis, underscoring the potential of this lipid mediator to rescue human brain cells in early stages of neurodegenerations.
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Affiliation(s)
- Yuhai Zhao
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Frederic Calon
- Molecular Endocrinology and Oncology Research Centre, Centre Hospitalier de l'Université Laval Research Centre (CHUL), Quebec, Canada
| | - Carl Julien
- Molecular Endocrinology and Oncology Research Centre, Centre Hospitalier de l'Université Laval Research Centre (CHUL), Quebec, Canada
| | - Jeremy W. Winkler
- Department of Chemistry, Loker Hydrocarbon Research Institute, University of Southern California, Los Angeles, California, United States of America
| | - Nicos A. Petasis
- Department of Chemistry, Loker Hydrocarbon Research Institute, University of Southern California, Los Angeles, California, United States of America
| | - Walter J. Lukiw
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Nicolas G. Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
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Mossello E, Ballini E, Mello AM, Tarantini F, Simoni D, Baldasseroni S, Marchionni N. Biomarkers of Alzheimer's disease: from central nervous system to periphery? Int J Alzheimers Dis 2010; 2011:342980. [PMID: 21197431 PMCID: PMC3010633 DOI: 10.4061/2011/342980] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 11/15/2010] [Indexed: 11/20/2022] Open
Abstract
Alzheimer's Disease (AD) is the most frequent form of dementia and represents one of the main causes of disability among older subjects. Up to now, the diagnosis of AD has been made according to clinical criteria. However, the use of such criteria does not allow an early diagnosis, as pathological alterations may be apparent many years before the clear-cut clinical picture. An early diagnosis is even more valuable to develop new treatments, potentially interfering with the pathogenetic process. During the last decade, several neuroimaging and cerebrospinal fluid (CSF) parameters have been introduced to allow an early and accurate detection of AD patients, and, recently, they have been included among research criteria for AD diagnosis. However, their use in clinical practice suffers from limitations both in accuracy and availability. The increasing amount of knowledge about peripheral biomarkers will possibly allow the future identification of reliable and easily available diagnostic tests.
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Affiliation(s)
- Enrico Mossello
- Unit of Gerontology and Geriatric Medicine, Department of Critical Care Medcine and Surgery, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy
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Alexopoulos P, Kurz A, Lewczuk P, Kornhuber J, Wiltfang J, Maier W, Förstl H, Perneczky R. The sortilin-related receptor SORL1 and the amyloid cascade: a possible explanation for the concurrent elevation of CSF soluble APPalpha and APPbeta in Alzheimer's disease. Int J Geriatr Psychiatry 2010; 25:542-3. [PMID: 20391590 DOI: 10.1002/gps.2349] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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20
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Muirhead KEA, Borger E, Aitken L, Conway SJ, Gunn-Moore FJ. The consequences of mitochondrial amyloid beta-peptide in Alzheimer's disease. Biochem J 2010; 426:255-70. [PMID: 20175748 DOI: 10.1042/bj20091941] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The Abeta (amyloid-beta peptide) has long been associated with Alzheimer's disease, originally in the form of extracellular plaques. However, in the present paper we review the growing evidence for the role of soluble intracellular Abeta in the disease progression, with particular reference to Abeta found within the mitochondria. Once inside the cell, Abeta is able to interact with a number of targets, including the mitochondrial proteins ABAD (amyloid-binding alcohol dehydrogenase) and CypD (cyclophilin D), which is a component of the mitochondrial permeability transition pore. Interference with the normal functions of these proteins results in disruption of cell homoeostasis and ultimately cell death. The present review explores the possible mechanisms by which cell death occurs, considering the evidence presented on a molecular, cellular and in vivo level.
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Affiliation(s)
- Kirsty E A Muirhead
- School of Biology, Bute Medical Building, University of St Andrews, Westburn Lane, St Andrews, Fife KY16 9TS, UK.
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21
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Ma QL, Galasko DR, Ringman JM, Vinters HV, Edland SD, Pomakian J, Ubeda OJ, Rosario ER, Teter B, Frautschy SA, Cole GM. Reduction of SorLA/LR11, a sorting protein limiting beta-amyloid production, in Alzheimer disease cerebrospinal fluid. ACTA ACUST UNITED AC 2009; 66:448-57. [PMID: 19364929 DOI: 10.1001/archneurol.2009.22] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND The sortilin-related receptor SorLA/LR11 (LR11) is a transmembrane neuronal sorting protein that reduces beta-amyloid precursor protein trafficking to secretases, notably BACE1 that generates beta-amyloid, the principal component of senile plaques in Alzheimer disease (AD). LR11 protein is reduced in patients with late-onset AD, and LR11 polymorphisms have been associated with late-onset AD. OBJECTIVE T o detect soluble LR11 and APP in cerebrospinal fluid (CSF) from patients with AD and control subjects, as (like beta-amyloid precursor protein) LR11 is cleaved near the membrane to release a large N-terminal fragment that is secreted to media from cultured cells. DESIGN Case-control study. SETTING Academic research. PARTICIPANTS Patients with AD and control subjects. MAIN OUTCOME MEASURES We evaluated CSF LR11, beta-amyloid precursor protein, and apolipoprotein E levels by Western blot in lumbar and postmortem CSF samples. RESULTS LR11 levels were detectable and stable during 6 months in the CSF of patients with AD. LR11 levels were significantly reduced in lumbar samples from patients with mild to moderate probable AD, as well as in ventricular CSF from patients with autopsy-confirmed AD (predominantly Braak stage III-IV). Bivariate analysis with beta-amyloid 42 and LR11 levels improved diagnostic specificity for AD. Reduced LR11 levels are significantly correlated with soluble beta-amyloid precursor protein but not apolipoprotein E levels. CONCLUSION Reduced LR11 levels in CSF of patients with AD may have potential as a diagnostic biomarker for patients with LR11 deficits that promote beta-amyloid production or as an index of therapeutic response in late-onset AD.
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Affiliation(s)
- Qiu-Lan Ma
- Department of Medicine, University of California, Los Angeles, California, USA
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Beecham GW, Martin ER, Li YJ, Slifer MA, Gilbert JR, Haines JL, Pericak-Vance MA. Genome-wide association study implicates a chromosome 12 risk locus for late-onset Alzheimer disease. Am J Hum Genet 2009; 84:35-43. [PMID: 19118814 DOI: 10.1016/j.ajhg.2008.12.008] [Citation(s) in RCA: 169] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Revised: 11/04/2008] [Accepted: 12/12/2008] [Indexed: 12/16/2022] Open
Abstract
Only Apolipoprotein E polymorphisms have been consistently associated with the risk of late-onset Alzheimer disease (LOAD), but they represent only a minority of the underlying genetic effect. To identify additional LOAD risk loci, we performed a genome-wide association study (GWAS) on 492 LOAD cases and 498 cognitive controls using Illumina's HumanHap550 beadchip. An additional 238 cases and 220 controls were used as a validation data set for single-nucleotide polymorphisms (SNPs) that met genome-wide significance. To validate additional associated SNPs (p < 0.0001) and nominally associated candidate genes, we imputed SNPs from our GWAS using a previously published LOAD GWAS(1) and the IMPUTE program. Association testing was performed with the Cochran-Armitage trend test and logistic regression, and genome-wide significance was determined with the False Discovery Rate-Beta Uniform Mixture method. Extensive quality-control methods were performed at both the sample and the SNP level. The GWAS confirmed the known APOE association and identified association with a 12q13 locus at genome-wide significance; the 12q13 locus was confirmed in our validation data set. Four additional highly associated signals (1q42, 4q28, 6q14, 19q13) were replicated with the use of the imputed data set, and six candidate genes had SNPs with nominal association in both the GWAS and the joint imputated data set. These results help to further define the genetic architecture of LOAD.
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Abstract
The dietary essential PUFA docosahexaenoic acid [DHA; 22:6(n-3)] is a critical contributor to cell structure and function in the nervous system, and deficits in DHA abundance are associated with cognitive decline during aging and in neurodegenerative disease. Recent studies underscore the importance of DHA-derived neuroprotectin D1 (NPD1) in the homeostatic regulation of brain cell survival and repair involving neurotrophic, antiapoptotic and antiinflammatory signaling. Emerging evidence suggests that NPD1 synthesis is activated by growth factors and neurotrophins. Evolving research indicates that NPD1 has important determinant and regulatory interactions with the molecular-genetic mechanisms affecting beta-amyloid precursor protein (betaAPP) and amyloid beta (Abeta) peptide neurobiology. Deficits in DHA or its peroxidation appear to contribute to inflammatory signaling, apoptosis, and neuronal dysfunction in Alzheimer disease (AD), a common and progressive age-related neurological disorder unique to structures and processes of the human brain. This article briefly reviews our current understanding of the interactions of DHA and NPD1 on betaAPP processing and Abeta peptide signaling and how this contributes to oxidative and pathogenic processes characteristic of aging and AD pathology.
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Lukiw WJ. Emerging amyloid beta (Ab) peptide modulators for the treatment of Alzheimer's disease (AD). Expert Opin Emerg Drugs 2008; 13:255-71. [PMID: 18537520 DOI: 10.1517/14728214.13.2.255] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND According to the 'amyloid cascade hypothesis' of Alzheimer's disease (AD), abnormal processing of beta-amyloid precursor protein (betaAPP) into toxic amyloid beta (Abeta)-peptides is central to the etiopathology of this uniquely human brain disorder. OBJECTIVE To review current AD drugs, pharmacological approaches and strategies aimed at modulating Abeta-peptide generation and/or aggregation in the treatment of AD. METHODS Data searches at various websites: Alzheimer Research Forum; individual drug company databases; Medline; Pharmaprojects database; unpublished research; inter-University research communications. RESULTS/CONCLUSION Considerable research effort has focused on secretase-mediated mechanisms of betaAPP processing, and the latest pharmacological strategies have used selective Abeta-peptide-lowering agents (SALA) to provide therapeutic benefit against Abeta-initiated neurodegenerative pathology. Currently, dedicated anticholinesterase, glutamatergic agonist and Abeta-peptide immunization have had little impact in the clinical treatment of AD. One unexpected benefit of statins (HMG-CoA inhibitors), besides their cholesterol lowering abilities, has been their ancillary effects in potentiating the enzymatic mechanisms that generate Abeta-peptides. The long-term benefits or complications of statin-based therapies for use in the clinical management of AD are not known.
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Affiliation(s)
- Walter J Lukiw
- Louisiana State University Health Sciences Center, LSU Neuroscience Center of Excellence, 2020 Gravier Street, Suite 8B8, New Orleans, LA 70112-2272, USA.
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Nekrasova T, Jobes ML, Ting JH, Wagner GC, Minden A. Targeted disruption of the Pak5 and Pak6 genes in mice leads to deficits in learning and locomotion. Dev Biol 2008; 322:95-108. [PMID: 18675265 DOI: 10.1016/j.ydbio.2008.07.006] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Revised: 06/12/2008] [Accepted: 07/07/2008] [Indexed: 11/26/2022]
Abstract
PAK6 is a member of the group B family of PAK serine/threonine kinases, and is highly expressed in the brain. The group B PAKs, including PAK4, PAK5, and PAK6, were first identified as effector proteins for the Rho GTPase Cdc42. They have important roles in filopodia formation, the extension of neurons, and cell survival. Pak4 knockout mice die in utero, and the embryos have several abnormalities, including a defect in the development of motor neurons. In contrast, Pak5 knockout mice do not have any noticeable abnormalities. So far nothing is known about the biological function of Pak6. To address this, we have deleted the Pak6 gene in mice. Since Pak6 and Pak5 are both expressed in the brain, we also generated Pak5/Pak6 double knockout mice. These mice were viable and fertile, but had several locomotor and behavioral deficits. Our results indicate that Pak5 and Pak6 together are not required for viability, but are required for a normal level of locomotion and activity as well as for learning and memory. This is consistent with a role for the group B PAKs in the nervous system.
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Affiliation(s)
- Tanya Nekrasova
- Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
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Kölsch H, Jessen F, Wiltfang J, Lewczuk P, Dichgans M, Kornhuber J, Frölich L, Heuser I, Peters O, Schulz JB, Schwab SG, Maier W. Influence of SORL1 gene variants: association with CSF amyloid-beta products in probable Alzheimer's disease. Neurosci Lett 2008; 440:68-71. [PMID: 18541377 DOI: 10.1016/j.neulet.2008.05.049] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Revised: 05/14/2008] [Accepted: 05/14/2008] [Indexed: 11/25/2022]
Abstract
SORL1 gene variants were described as risk factors of Alzheimer's disease (AD). We investigated the association of four SORL1 variants with CSF levels of Abeta42 and Abeta40 in 153 AD patients recruited from a multicenter study of the German Competence Net Dementias. Only one SORL1 SNP was associated with altered Abeta42 levels in the single marker analysis (SNP21: p=0.011), the other SNPs did not show an association with Abeta42 or Abeta40 CSF levels. Haplotype analysis identified a three marker SORL1 haplotype consisting of SNP19 T-allele, SNP21 G-allele and SNP23 A-allele (T/G/A) which was associated with reduced Abeta42 CSF levels in AD patients (p=0.003). Abeta40 levels were also lower in carriers of this haplotype; however, this did not reach statistical significance (p=0.15). We found a SORL1 haplotype which was associated with CSF levels of amyloid-beta cleavage products, measured as altered levels of Abeta42. Thus our data suggest that SORL1 gene variants might influence AD pathology.
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Affiliation(s)
- Heike Kölsch
- Department of Psychiatry, University of Bonn, Bonn, Germany.
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Tan EK, Lee J, Chen CP, Teo YY, Zhao Y, Lee WL. SORL1 haplotypes modulate risk of Alzheimer's disease in Chinese. Neurobiol Aging 2007; 30:1048-51. [PMID: 18063222 DOI: 10.1016/j.neurobiolaging.2007.10.013] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2007] [Revised: 10/18/2007] [Accepted: 10/25/2007] [Indexed: 11/17/2022]
Abstract
Genetic variants of the neuronal sortilin-related receptor (SORL1) have been demonstrated to modulate the risk of Alzheimer's disease (AD) in different American and European populations [Rogaeva, E., Meng, Y., Lee, J.H., Gu, Y., Kawarai, T., Zou, F., Katayama, T., Baldwin, C.T., Cheng, R., Hasegawa, H., Chen, F., Shibata, N., Lunetta, K.L., Pardossi-Piquard, R., Bohm, C., Wakutani, Y., Cupples, L.A., Cuenco, K.T., Green, R.C., Pinessi, L., Rainero, I., Sorbi, S., Bruni, A., Duara, R., Friedland, R.P., Inzelberg, R., Hampe, W., Bujo, H., Song, Y.Q., Andersen, O.M., Willnow, T.E., Graff-Radford, N., Petersen, R.C., Dickson, D., Der, S.D., Fraser, P.E., Schmitt-Ulms, G., Younkin, S., Mayeux, R., Farrer, L.A., St George-Hyslop, P., 2007. The neuronal sortilin-related receptor SORL1 is genetically associated with Alzheimer disease. Nat. Genet. 39 (2), 168-177]. We conducted haloptype analysis involving two genetic clusters of SORL1 in AD and controls among Han Chinese. rs3824968 (SNP 23) was associated with an increased risk of AD, and there was a trend towards association for rs1699102 (SNP 22) and rs2282649 (SNP 24). More robust associations were found for three-loci haplotypes. In particular, the GCA haplotype at SNPs 19-22-23 was associated with an increased risk (odds ratio 1.4), and CTC haplotype at SNPs 19-22-23 and TCT at SNPs 22-23-24 a decreased risk (odds ratio 0.67) of AD. The complete absence of some at-risk North European haplotypes in our Chinese study subjects was likely due to different ancestral origins, with allelic heterogeneity among races. However, our study suggests that certain SORL1 haplotypes at SNPs 19-24 modulated risk of AD in our Chinese population.
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Affiliation(s)
- E K Tan
- Department of Neurology, Singapore General Hospital, Singapore, Singapore.
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