1
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Mistry H, Richardson CD, Higginbottom A, Ashford B, Ahamed SU, Moore Z, Matthews FE, Brayne C, Simpson JE, Wharton SB. Relationships of brain cholesterol and cholesterol biosynthetic enzymes to Alzheimer's pathology and dementia in the CFAS population-derived neuropathology cohort. Neurosci Res 2024:S0168-0102(24)00007-5. [PMID: 38278219 DOI: 10.1016/j.neures.2024.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 01/05/2024] [Accepted: 01/17/2024] [Indexed: 01/28/2024]
Abstract
Altered cholesterol metabolism is implicated in brain ageing and Alzheimer's disease. We examined whether key genes regulating cholesterol metabolism and levels of brain cholesterol are altered in dementia and Alzheimer's disease neuropathological change (ADNC). Temporal cortex (n = 99) was obtained from the Cognitive Function and Ageing Study. Expression of the cholesterol biosynthesis rate-limiting enzyme HMG-CoA reductase (HMGCR) and its regulator, SREBP2, were detected using immunohistochemistry. Expression of HMGCR, SREBP2, CYP46A1 and ABCA1 were quantified by qPCR in samples enriched for astrocyte and neuronal RNA following laser-capture microdissection. Total cortical cholesterol was measured using the Amplex Red assay. HMGCR and SREBP2 proteins were predominantly expressed in pyramidal neurones, and in glia. Neuronal HMGCR did not vary with ADNC, oxidative stress, neuroinflammation or dementia status. Expression of HMGCR neuronal mRNA decreased with ADNC (p = 0.022) and increased with neuronal DNA damage (p = 0.049), whilst SREBP2 increased with ADNC (p = 0.005). High or moderate tertiles for cholesterol levels were associated with increased dementia risk (OR 1.44, 1.58). APOE ε4 allele was not associated with cortical cholesterol levels. ADNC is associated with gene expression changes that may impair cholesterol biosynthesis in neurones but not astrocytes, whilst levels of cortical cholesterol show a weak relationship to dementia status.
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Affiliation(s)
- Hemant Mistry
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | | | - Adrian Higginbottom
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | - Bridget Ashford
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | - Saif U Ahamed
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | - Zoe Moore
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | | | - Carol Brayne
- Cambridge Public Health, University of Cambridge, UK
| | - Julie E Simpson
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK.
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2
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Area-Gomez E, Schon EA. Towards a Unitary Hypothesis of Alzheimer's Disease Pathogenesis. J Alzheimers Dis 2024; 98:1243-1275. [PMID: 38578892 DOI: 10.3233/jad-231318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2024]
Abstract
The "amyloid cascade" hypothesis of Alzheimer's disease (AD) pathogenesis invokes the accumulation in the brain of plaques (containing the amyloid-β protein precursor [AβPP] cleavage product amyloid-β [Aβ]) and tangles (containing hyperphosphorylated tau) as drivers of pathogenesis. However, the poor track record of clinical trials based on this hypothesis suggests that the accumulation of these peptides is not the only cause of AD. Here, an alternative hypothesis is proposed in which the AβPP cleavage product C99, not Aβ, is the main culprit, via its role as a regulator of cholesterol metabolism. C99, which is a cholesterol sensor, promotes the formation of mitochondria-associated endoplasmic reticulum (ER) membranes (MAM), a cholesterol-rich lipid raft-like subdomain of the ER that communicates, both physically and biochemically, with mitochondria. We propose that in early-onset AD (EOAD), MAM-localized C99 is elevated above normal levels, resulting in increased transport of cholesterol from the plasma membrane to membranes of intracellular organelles, such as ER/endosomes, thereby upregulating MAM function and driving pathology. By the same token, late-onset AD (LOAD) is triggered by any genetic variant that increases the accumulation of intracellular cholesterol that, in turn, boosts the levels of C99 and again upregulates MAM function. Thus, the functional cause of AD is upregulated MAM function that, in turn, causes the hallmark disease phenotypes, including the plaques and tangles. Accordingly, the MAM hypothesis invokes two key interrelated elements, C99 and cholesterol, that converge at the MAM to drive AD pathogenesis. From this perspective, AD is, at bottom, a lipid disorder.
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Affiliation(s)
- Estela Area-Gomez
- Department of Neurology, Columbia University, New York, NY, USA
- Centro de Investigaciones Biológicas "Margarita Salas", Spanish National Research Council, Madrid, Spain
| | - Eric A Schon
- Department of Neurology, Columbia University, New York, NY, USA
- Department of Genetics and Development>, Columbia University, New York, NY, USA
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3
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Rudajev V, Novotny J. Cholesterol-dependent amyloid β production: space for multifarious interactions between amyloid precursor protein, secretases, and cholesterol. Cell Biosci 2023; 13:171. [PMID: 37705117 PMCID: PMC10500844 DOI: 10.1186/s13578-023-01127-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 09/05/2023] [Indexed: 09/15/2023] Open
Abstract
Amyloid β is considered a key player in the development and progression of Alzheimer's disease (AD). Many studies investigating the effect of statins on lowering cholesterol suggest that there may be a link between cholesterol levels and AD pathology. Since cholesterol is one of the most abundant lipid molecules, especially in brain tissue, it affects most membrane-related processes, including the formation of the most dangerous form of amyloid β, Aβ42. The entire Aβ production system, which includes the amyloid precursor protein (APP), β-secretase, and the complex of γ-secretase, is highly dependent on membrane cholesterol content. Moreover, cholesterol can affect amyloidogenesis in many ways. Cholesterol influences the stability and activity of secretases, but also dictates their partitioning into specific cellular compartments and cholesterol-enriched lipid rafts, where the amyloidogenic machinery is predominantly localized. The most complicated relationships have been found in the interaction between cholesterol and APP, where cholesterol affects not only APP localization but also the precise character of APP dimerization and APP processing by γ-secretase, which is important for the production of Aβ of different lengths. In this review, we describe the intricate web of interdependence between cellular cholesterol levels, cholesterol membrane distribution, and cholesterol-dependent production of Aβ, the major player in AD.
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Affiliation(s)
- Vladimir Rudajev
- Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jiri Novotny
- Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
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4
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Van Acker ZP, Perdok A, Hellemans R, North K, Vorsters I, Cappel C, Dehairs J, Swinnen JV, Sannerud R, Bretou M, Damme M, Annaert W. Phospholipase D3 degrades mitochondrial DNA to regulate nucleotide signaling and APP metabolism. Nat Commun 2023; 14:2847. [PMID: 37225734 DOI: 10.1038/s41467-023-38501-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 05/04/2023] [Indexed: 05/26/2023] Open
Abstract
Phospholipase D3 (PLD3) polymorphisms are linked to late-onset Alzheimer's disease (LOAD). Being a lysosomal 5'-3' exonuclease, its neuronal substrates remained unknown as well as how a defective lysosomal nucleotide catabolism connects to AD-proteinopathy. We identified mitochondrial DNA (mtDNA) as a major physiological substrate and show its manifest build-up in lysosomes of PLD3-defective cells. mtDNA accretion creates a degradative (proteolytic) bottleneck that presents at the ultrastructural level as a marked abundance of multilamellar bodies, often containing mitochondrial remnants, which correlates with increased PINK1-dependent mitophagy. Lysosomal leakage of mtDNA to the cytosol activates cGAS-STING signaling that upregulates autophagy and induces amyloid precursor C-terminal fragment (APP-CTF) and cholesterol accumulation. STING inhibition largely normalizes APP-CTF levels, whereas an APP knockout in PLD3-deficient backgrounds lowers STING activation and normalizes cholesterol biosynthesis. Collectively, we demonstrate molecular cross-talks through feedforward loops between lysosomal nucleotide turnover, cGAS-STING and APP metabolism that, when dysregulated, result in neuronal endolysosomal demise as observed in LOAD.
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Affiliation(s)
- Zoë P Van Acker
- Laboratory for Membrane Trafficking, VIB Center for Brain & Disease Research, Herestraat 49, box 602, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Herestraat 49, box 602, Leuven, Belgium
| | - Anika Perdok
- Laboratory for Membrane Trafficking, VIB Center for Brain & Disease Research, Herestraat 49, box 602, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Herestraat 49, box 602, Leuven, Belgium
| | - Ruben Hellemans
- Laboratory for Membrane Trafficking, VIB Center for Brain & Disease Research, Herestraat 49, box 602, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Herestraat 49, box 602, Leuven, Belgium
| | - Katherine North
- Laboratory for Membrane Trafficking, VIB Center for Brain & Disease Research, Herestraat 49, box 602, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Herestraat 49, box 602, Leuven, Belgium
| | - Inge Vorsters
- Laboratory for Membrane Trafficking, VIB Center for Brain & Disease Research, Herestraat 49, box 602, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Herestraat 49, box 602, Leuven, Belgium
| | - Cedric Cappel
- Laboratory for Molecular Cell Biology and Transgenic Research, Institute of Biochemistry, Christian-Albrechts-University Kiel, Otto-Hahn-Platz 9, Kiel, Germany
| | - Jonas Dehairs
- Laboratory of Lipid Metabolism & Cancer, Department of Oncology, KU Leuven, B-3000, Leuven, Belgium
| | - Johannes V Swinnen
- Laboratory of Lipid Metabolism & Cancer, Department of Oncology, KU Leuven, B-3000, Leuven, Belgium
| | - Ragna Sannerud
- Laboratory for Membrane Trafficking, VIB Center for Brain & Disease Research, Herestraat 49, box 602, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Herestraat 49, box 602, Leuven, Belgium
| | - Marine Bretou
- Laboratory for Membrane Trafficking, VIB Center for Brain & Disease Research, Herestraat 49, box 602, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Herestraat 49, box 602, Leuven, Belgium
| | - Markus Damme
- Laboratory for Molecular Cell Biology and Transgenic Research, Institute of Biochemistry, Christian-Albrechts-University Kiel, Otto-Hahn-Platz 9, Kiel, Germany
| | - Wim Annaert
- Laboratory for Membrane Trafficking, VIB Center for Brain & Disease Research, Herestraat 49, box 602, Leuven, Belgium.
- Department of Neurosciences, KU Leuven, Herestraat 49, box 602, Leuven, Belgium.
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5
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Huang Y, Zhang W, Guo X, Zhang Y, Wu J, Zu H. Cellular cholesterol loss by DHCR24 knockdown leads to Aβ production by changing APP intracellular localization. J Lipid Res 2023; 64:100367. [PMID: 37011864 PMCID: PMC10173783 DOI: 10.1016/j.jlr.2023.100367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/23/2023] [Accepted: 03/16/2023] [Indexed: 04/03/2023] Open
Abstract
For the past 20 years, the majority of cell culture studies reported that increasing cholesterol level increases amyloid-β (Aβ) production. Conversely, other studies and genetic evidences support that cellular cholesterol loss leads to Aβ generation. As a highly controversial issue in Alzheimer's disease (AD) pathogenesis,the apparent contradiction prompted us to again explore the role of cellular cholesterol in Aβ production. Here, we adopted new neuronal and astrocytic cell models induced by 3β-hydroxysterol-Δ24 reductase (DHCR24), which obviously differ from the widely used cell models with overexpressing amyloid precursor protein (APP) in the majority of previous studies. In neuronal and astrocytic cell model, we found that deficiency of cellular cholesterol by DHCR24 knock-down obviously increased intracellular and extracellular Aβ generation. Importantly, in cell models with overexpressing APP, we found that APP overexpression could disrupt cellular cholesterol homeostasis and affect function of cells, coupled with the increase of APP β-cleavage product, 99-residue transmembrane C-terminal domain (C99). Therefore, we suppose the results derived from the APP knock-in models will need to be re-evaluated. One rational explanation for the discrepancy between our outcomes and the previous studies could be attributed to the two different cell models. Mechanistically, we showed that cellular cholesterol loss obviously altered APP intracellular localization by affecting cholesterol-related trafficking protein of APP. Therefore, our outcomes strongly support cellular cholesterol loss by DHCR24 knockdown leads to Aβ production.
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6
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Yin F. Lipid metabolism and Alzheimer's disease: clinical evidence, mechanistic link and therapeutic promise. FEBS J 2023; 290:1420-1453. [PMID: 34997690 PMCID: PMC9259766 DOI: 10.1111/febs.16344] [Citation(s) in RCA: 59] [Impact Index Per Article: 59.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 12/14/2021] [Accepted: 01/05/2022] [Indexed: 02/06/2023]
Abstract
Alzheimer's disease (AD) is an age-associated neurodegenerative disorder with multifactorial etiology, intersecting genetic and environmental risk factors, and a lack of disease-modifying therapeutics. While the abnormal accumulation of lipids was described in the very first report of AD neuropathology, it was not until recent decades that lipid dyshomeostasis became a focus of AD research. Clinically, lipidomic and metabolomic studies have consistently shown alterations in the levels of various lipid classes emerging in early stages of AD brains. Mechanistically, decades of discovery research have revealed multifaceted interactions between lipid metabolism and key AD pathogenic mechanisms including amyloidogenesis, bioenergetic deficit, oxidative stress, neuroinflammation, and myelin degeneration. In the present review, converging evidence defining lipid dyshomeostasis in AD is summarized, followed by discussions on mechanisms by which lipid metabolism contributes to pathogenesis and modifies disease risk. Furthermore, lipid-targeting therapeutic strategies, and the modification of their efficacy by disease stage, ApoE status, and metabolic and vascular profiles, are reviewed.
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Affiliation(s)
- Fei Yin
- Center for Innovation in Brain Science, University of Arizona Health Sciences, Tucson, AZ, USA.,Department of Pharmacology, College of Medicine Tucson, University of Arizona, Tucson, AZ, USA.,Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Tucson, AZ, USA
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7
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Cohen LD, Ziv T, Ziv NE. Synapse integrity and function: Dependence on protein synthesis and identification of potential failure points. Front Mol Neurosci 2022; 15:1038614. [PMID: 36583084 PMCID: PMC9792512 DOI: 10.3389/fnmol.2022.1038614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 11/07/2022] [Indexed: 12/14/2022] Open
Abstract
Synaptic integrity and function depend on myriad proteins - labile molecules with finite lifetimes that need to be continually replaced with freshly synthesized copies. Here we describe experiments designed to expose synaptic (and neuronal) properties and functions that are particularly sensitive to disruptions in protein supply, identify proteins lost early upon such disruptions, and uncover potential, yet currently underappreciated failure points. We report here that acute suppressions of protein synthesis are followed within hours by reductions in spontaneous network activity levels, impaired oxidative phosphorylation and mitochondrial function, and, importantly, destabilization and loss of both excitatory and inhibitory postsynaptic specializations. Conversely, gross impairments in presynaptic vesicle recycling occur over longer time scales (days), as does overt cell death. Proteomic analysis identified groups of potentially essential 'early-lost' proteins including regulators of synapse stability, proteins related to bioenergetics, fatty acid and lipid metabolism, and, unexpectedly, numerous proteins involved in Alzheimer's disease pathology and amyloid beta processing. Collectively, these findings point to neuronal excitability, energy supply and synaptic stability as early-occurring failure points under conditions of compromised supply of newly synthesized protein copies.
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Affiliation(s)
- Laurie D. Cohen
- Technion Faculty of Medicine, Rappaport Institute and Network Biology Research Laboratories, Haifa, Israel
| | - Tamar Ziv
- Smoler Proteomics Center, Lokey Interdisciplinary Center for Life Sciences & Engineering, Technion, Haifa, Israel
| | - Noam E. Ziv
- Technion Faculty of Medicine, Rappaport Institute and Network Biology Research Laboratories, Haifa, Israel,*Correspondence: Noam E. Ziv,
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8
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Png G, Gerlini R, Hatzikotoulas K, Barysenka A, Rayner NW, Klarić L, Rathkolb B, Aguilar-Pimentel JA, Rozman J, Fuchs H, Gailus-Durner V, Tsafantakis E, Karaleftheri M, Dedoussis G, Pietrzik C, Wilson JF, Angelis MH, Becker-Pauly C, Gilly A, Zeggini E. Identifying causal serum protein-cardiometabolic trait relationships using whole genome sequencing. Hum Mol Genet 2022; 32:1266-1275. [PMID: 36349687 PMCID: PMC10077504 DOI: 10.1093/hmg/ddac275] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 10/24/2022] [Accepted: 10/27/2022] [Indexed: 11/10/2022] Open
Abstract
Cardiometabolic diseases, such as type 2 diabetes and cardiovascular disease, have a high public health burden. Understanding the genetically-determined regulation of proteins that are dysregulated in disease can help to dissect the complex biology underpinning them. Here, we perform a protein quantitative trait locus (pQTL) analysis of 255 serum proteins relevant to cardiometabolic processes in 2893 individuals. Meta-analysing whole-genome sequencing (WGS) data from two Greek cohorts, MANOLIS (n = 1356; 22.5x WGS) and Pomak (n = 1537; 18.4x WGS), we detect 302 independently-associated pQTL variants for 171 proteins, including 12 rare variants (minor allele frequency [MAF] < 1%). We additionally find 15 pQTL variants that are rare in non-Finnish European populations, but have drifted up in frequency in the discovery cohorts here. We identify proteins causally associated with cardiometabolic traits, including MEP1B for high-density lipoprotein levels; and describe a knock-out Mep1b mouse model. Our findings furnish insights into the genetic architecture of the serum proteome, identify new protein-disease relationships, and demonstrate the importance of isolated populations in pQTL analysis.
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Affiliation(s)
- Grace Png
- Institute of Translational Genomics, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany.,Technical University of Munich (TUM), School of Medicine, Munich, Germany
| | - Raffaele Gerlini
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Konstantinos Hatzikotoulas
- Institute of Translational Genomics, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Andrei Barysenka
- Institute of Translational Genomics, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - N William Rayner
- Institute of Translational Genomics, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Lucija Klarić
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom
| | - Birgit Rathkolb
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany.,Institute of Molecular Animal Breeding and Biotechnology, Gene Center, Ludwig-Maximilians University Munich, Munich, Germany
| | - Juan A Aguilar-Pimentel
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Jan Rozman
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany.,Institute of Molecular Genetics of the Czech Academy of Sciences, Czech Centre for Phenogenomics, Vestec, Czech Republic
| | - Helmut Fuchs
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Valerie Gailus-Durner
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | | | | | - George Dedoussis
- Department of Nutrition and Dietetics, School of Health Science and Education, Harokopio University of Athens, Athens, Greece
| | - Claus Pietrzik
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - James F Wilson
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom.,Centre for Global Health Research, Usher Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Martin Hrabe Angelis
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany.,Chair of Experimental Genetics, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Christoph Becker-Pauly
- Institute of Biochemistry, Unit for Degradomics of the Protease Web, University of Kiel, Kiel, Germany
| | - Arthur Gilly
- Institute of Translational Genomics, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Eleftheria Zeggini
- Institute of Translational Genomics, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany.,Technical University of Munich (TUM) and Klinikum Rechts der Isar, TUM School of Medicine, Munich, Germany
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9
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Hanbouch L, Schaack B, Kasri A, Fontaine G, Gkanatsiou E, Brinkmalm G, Camporesi E, Portelius E, Blennow K, Mourier G, Gilles N, Millan MJ, Marquer C, Zetterberg H, Boussicault L, Potier MC. Specific Mutations in the Cholesterol-Binding Site of APP Alter Its Processing and Favor the Production of Shorter, Less Toxic Aβ Peptides. Mol Neurobiol 2022; 59:7056-7073. [PMID: 36076005 PMCID: PMC9525381 DOI: 10.1007/s12035-022-03025-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 08/31/2022] [Indexed: 12/05/2022]
Abstract
Excess brain cholesterol is strongly implicated in the pathogenesis of Alzheimer's disease (AD). Here we evaluated how the presence of a cholesterol-binding site (CBS) in the transmembrane and juxtamembrane regions of the amyloid precursor protein (APP) regulates its processing. We generated nine point mutations in the APP gene, changing the charge and/or hydrophobicity of the amino-acids which were previously shown as part of the CBS. Most mutations triggered a reduction of amyloid-β peptides Aβ40 and Aβ42 secretion from transiently transfected HEK293T cells. Only the mutations at position 28 of Aβ in the APP sequence resulted in a concomitant significant increase in the production of shorter Aβ peptides. Mass spectrometry (MS) confirmed the predominance of Aβx-33 and Aβx-34 with the APPK28A mutant. The enzymatic activity of α-, β-, and γ-secretases remained unchanged in cells expressing all mutants. Similarly, subcellular localization of the mutants in early endosomes did not differ from the APPWT protein. A transient increase of plasma membrane cholesterol enhanced the production of Aβ40 and Aβ42 by APPWT, an effect absent in APPK28A mutant. Finally, WT but not CBS mutant Aβ derived peptides bound to cholesterol-rich exosomes. Collectively, the present data revealed a major role of juxtamembrane amino acids of the APP CBS in modulating the production of toxic Aβ species. More generally, they underpin the role of cholesterol in the pathophysiology of AD.
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Affiliation(s)
- Linda Hanbouch
- Paris Brain Institute, ICM, CNRS UMR7225-INSERM U1127-Sorbonne University Hôpital de La Pitié-Salpêtrière, 47 Bd de l'Hôpital, 75013, Paris, France
| | - Béatrice Schaack
- Univ. Grenoble Alpes, CNRS, INP, TheRex Team, TIMC-IMAG, 38700, La Tronche, France
- Univ. Grenoble Alpes, CEA, CNRS, IBS, 38044, Grenoble, France
| | - Amal Kasri
- Paris Brain Institute, ICM, CNRS UMR7225-INSERM U1127-Sorbonne University Hôpital de La Pitié-Salpêtrière, 47 Bd de l'Hôpital, 75013, Paris, France
| | - Gaëlle Fontaine
- Paris Brain Institute, ICM, CNRS UMR7225-INSERM U1127-Sorbonne University Hôpital de La Pitié-Salpêtrière, 47 Bd de l'Hôpital, 75013, Paris, France
| | - Eleni Gkanatsiou
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience & Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, S-431 80, Sweden
| | - Gunnar Brinkmalm
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience & Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, S-431 80, Sweden
| | - Elena Camporesi
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience & Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, S-431 80, Sweden
| | - Erik Portelius
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience & Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, S-431 80, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, S-431 80, Mölndal, Sweden
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience & Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, S-431 80, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, S-431 80, Mölndal, Sweden
| | - Gilles Mourier
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, S-431 80, Mölndal, Sweden
- Département Médicaments Et Technologies Pour La Santé (DMTS), Université Paris Saclay, CEA, INRAE, SIMoS, 91191, Gif-sur-Yvette, France
| | - Nicolas Gilles
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, S-431 80, Mölndal, Sweden
- Département Médicaments Et Technologies Pour La Santé (DMTS), Université Paris Saclay, CEA, INRAE, SIMoS, 91191, Gif-sur-Yvette, France
| | - Mark J Millan
- Neuroscience Inflammation Thérapeutic Area, IDR Servier, 125 Chemin de Ronde, 78290, Croissy-sur-Seine, France
- Institute of Neuroscience and Psychology, College of Medicine, Vet and Life Sciences, Glasgow University, 62 Hillhead Street, Glasgow, G12 8QB, Scotland
| | - Catherine Marquer
- Paris Brain Institute, ICM, CNRS UMR7225-INSERM U1127-Sorbonne University Hôpital de La Pitié-Salpêtrière, 47 Bd de l'Hôpital, 75013, Paris, France
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience & Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, S-431 80, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, S-431 80, Mölndal, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG, UK
- UK Dementia Research Institute at UCL, London, WC1E 6BT, UK
| | - Lydie Boussicault
- Paris Brain Institute, ICM, CNRS UMR7225-INSERM U1127-Sorbonne University Hôpital de La Pitié-Salpêtrière, 47 Bd de l'Hôpital, 75013, Paris, France
| | - Marie-Claude Potier
- Paris Brain Institute, ICM, CNRS UMR7225-INSERM U1127-Sorbonne University Hôpital de La Pitié-Salpêtrière, 47 Bd de l'Hôpital, 75013, Paris, France.
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10
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Rudajev V, Novotny J. Cholesterol as a key player in amyloid β-mediated toxicity in Alzheimer’s disease. Front Mol Neurosci 2022; 15:937056. [PMID: 36090253 PMCID: PMC9453481 DOI: 10.3389/fnmol.2022.937056] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disorder that is one of the most devastating and widespread diseases worldwide, mainly affecting the aging population. One of the key factors contributing to AD-related neurotoxicity is the production and aggregation of amyloid β (Aβ). Many studies have shown the ability of Aβ to bind to the cell membrane and disrupt its structure, leading to cell death. Because amyloid damage affects different parts of the brain differently, it seems likely that not only Aβ but also the nature of the membrane interface with which the amyloid interacts, helps determine the final neurotoxic effect. Because cholesterol is the dominant component of the plasma membrane, it plays an important role in Aβ-induced toxicity. Elevated cholesterol levels and their regulation by statins have been shown to be important factors influencing the progression of neurodegeneration. However, data from many studies have shown that cholesterol has both neuroprotective and aggravating effects in relation to the development of AD. In this review, we attempt to summarize recent findings on the role of cholesterol in Aβ toxicity mediated by membrane binding in the pathogenesis of AD and to consider it in the broader context of the lipid composition of cell membranes.
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11
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Jose M, Sivanand A, Channakeshava C. Membrane Cholesterol Is a Critical Determinant for Hippocampal Neuronal Polarity. Front Mol Neurosci 2021; 14:746211. [PMID: 34744625 PMCID: PMC8566733 DOI: 10.3389/fnmol.2021.746211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 10/04/2021] [Indexed: 11/13/2022] Open
Abstract
Maintaining a normal cholesterol balance is crucial for the functioning of a healthy brain. Dysregulation in cholesterol metabolism and homeostasis in the brain have been correlated to various neurological disorders. The majority of previous studies in primary cultures focus on the role of cholesterol balance in neuronal development after polarity has been established. Here we have investigated how transient alteration of membrane lipids, specifically cholesterol, affects neuronal development and polarity in developing hippocampal neurons prior to polarity establishment, soon after initiation of neurite outgrowth. We observed that temporary cholesterol perturbation affects axonal and dendritic development differentially in an opposing manner. Transient membrane cholesterol deficiency increased neuronal population with a single neurite, simultaneously generating a second population of neurons with supernumerary axons. Brief replenishment of cholesterol immediately after cholesterol sequestering rescued neuronal development defects and restored polarity. The results showed a small window of cholesterol concentration to be complementing neurite outgrowth, polarity reestablishment, and in determining the normal neuronal morphology, emphasizing the critical role of precise membrane lipid balance in defining the neuronal architecture. Membrane cholesterol enhancement modified neurite outgrowth but did not significantly alter polarity. Cholesterol sequestering at later stages of development has shown to enhance neurite outgrowth, whereas distinct effects for neurite development and polarity were observed at early developmental stages, signifying the relevance of precise membrane cholesterol balance in altering neuronal physiology. Our results confirm cholesterol to be a key determinant for axo-dendritic specification and neuronal architecture and emphasize the possibility to reverse neuronal developmental defects caused by cholesterol deficiency by modulating membrane cholesterol during the early developmental stages.
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Affiliation(s)
- Mini Jose
- Centre for Neuroscience, Indian institute of Science, Bangalore, India
| | - Aiswarya Sivanand
- Centre for Neuroscience, Indian institute of Science, Bangalore, India
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12
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Sáez-Orellana F, Leroy T, Ribeiro F, Kreis A, Leroy K, Lalloyer F, Baugé E, Staels B, Duyckaerts C, Brion JP, Gailly P, Octave JN, Pierrot N. Regulation of PPARα by APP in Alzheimer disease affects the pharmacological modulation of synaptic activity. JCI Insight 2021; 6:e150099. [PMID: 34228639 PMCID: PMC8410016 DOI: 10.1172/jci.insight.150099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/30/2021] [Indexed: 11/17/2022] Open
Abstract
Among genetic susceptibility loci associated with late-onset Alzheimer disease (LOAD), genetic polymorphisms identified in genes encoding lipid carriers led to the hypothesis that a disruption of lipid metabolism could promote disease progression. We previously reported that amyloid precursor protein (APP) involved in Alzheimer disease (AD) physiopathology impairs lipid synthesis needed for cortical networks' activity and that activation of peroxisome proliferator-activated receptor α (PPARα), a metabolic regulator involved in lipid metabolism, improves synaptic plasticity in an AD mouse model. These observations led us to investigate a possible correlation between PPARα function and full-length APP expression. Here, we report that PPARα expression and activation were inversely related to APP expression both in LOAD brains and in early-onset AD cases with a duplication of the APP gene, but not in control human brains. Moreover, human APP expression decreased PPARA expression and its related target genes in transgenic mice and in cultured cortical cells, while opposite results were observed in APP-silenced cortical networks. In cultured neurons, APP-mediated decrease or increase in synaptic activity was corrected by a PPARα-specific agonist and antagonist, respectively. APP-mediated control of synaptic activity was abolished following PPARα deficiency, indicating a key function of PPARα in this process.
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Affiliation(s)
| | | | | | - Anna Kreis
- Laboratory of Cell Physiology, Institute of Neuroscience, Catholic University of Louvain, Brussels, Belgium
| | - Karelle Leroy
- Laboratory of Histology and Neuropathology, Free University of Brussels, Brussels, Belgium
| | - Fanny Lalloyer
- University of Lille, INSERM, CHU Lille, Pasteur Institute of Lille, U1011, Lille, France
| | - Eric Baugé
- University of Lille, INSERM, CHU Lille, Pasteur Institute of Lille, U1011, Lille, France
| | - Bart Staels
- University of Lille, INSERM, CHU Lille, Pasteur Institute of Lille, U1011, Lille, France
| | - Charles Duyckaerts
- University of Sorbonne, Pitié-Salpêtrière University Hospital, and Paris Brain Institute, CNRS UMR7225, INSERM U1127, Paris, France
| | - Jean-Pierre Brion
- Laboratory of Histology and Neuropathology, Free University of Brussels, Brussels, Belgium
| | - Philippe Gailly
- Laboratory of Cell Physiology, Institute of Neuroscience, Catholic University of Louvain, Brussels, Belgium
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13
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Feringa FM, van der Kant R. Cholesterol and Alzheimer's Disease; From Risk Genes to Pathological Effects. Front Aging Neurosci 2021; 13:690372. [PMID: 34248607 PMCID: PMC8264368 DOI: 10.3389/fnagi.2021.690372] [Citation(s) in RCA: 98] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 05/28/2021] [Indexed: 12/22/2022] Open
Abstract
While the central nervous system compromises 2% of our body weight, it harbors up to 25% of the body's cholesterol. Cholesterol levels in the brain are tightly regulated for physiological brain function, but mounting evidence indicates that excessive cholesterol accumulates in Alzheimer's disease (AD), where it may drive AD-associated pathological changes. This seems especially relevant for late-onset AD, as several of the major genetic risk factors are functionally associated with cholesterol metabolism. In this review we discuss the different systems that maintain brain cholesterol metabolism in the healthy brain, and how dysregulation of these processes can lead, or contribute to, Alzheimer's disease. We will also discuss how AD-risk genes might impact cholesterol metabolism and downstream AD pathology. Finally, we will address the major outstanding questions in the field and how recent technical advances in CRISPR/Cas9-gene editing and induced pluripotent stem cell (iPSC)-technology can aid to study these problems.
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Affiliation(s)
- Femke M. Feringa
- Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam University Medical Center, Amsterdam, Netherlands
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, Amsterdam, Netherlands
| | - Rik van der Kant
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, Amsterdam, Netherlands
- Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Amsterdam University Medical Center, Amsterdam, Netherlands
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14
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Capone R, Tiwari A, Hadziselimovic A, Peskova Y, Hutchison JM, Sanders CR, Kenworthy AK. The C99 domain of the amyloid precursor protein resides in the disordered membrane phase. J Biol Chem 2021; 296:100652. [PMID: 33839158 PMCID: PMC8113881 DOI: 10.1016/j.jbc.2021.100652] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 04/02/2021] [Accepted: 04/07/2021] [Indexed: 12/11/2022] Open
Abstract
Processing of the amyloid precursor protein (APP) via the amyloidogenic pathway is associated with the etiology of Alzheimer's disease. The cleavage of APP by β-secretase to generate the transmembrane 99-residue C-terminal fragment (C99) and subsequent processing of C99 by γ-secretase to yield amyloid-β (Aβ) peptides are essential steps in this pathway. Biochemical evidence suggests that amyloidogenic processing of C99 occurs in cholesterol- and sphingolipid-enriched liquid-ordered phase membrane rafts. However, direct evidence that C99 preferentially associates with these rafts has remained elusive. Here, we tested this by quantifying the affinity of C99-GFP for raft domains in cell-derived giant plasma membrane vesicles (GPMVs). We found that C99 was essentially excluded from ordered domains in vesicles from HeLa cells, undifferentiated SH-SY5Y cells, or SH-SY5Y-derived neurons; instead, ∼90% of C99 partitioned into disordered domains. The strong association of C99 with disordered domains occurred independently of its cholesterol-binding activity or homodimerization, or of the presence of the familial Alzheimer disease Arctic mutation (APP E693G). Finally, through biochemical studies we confirmed previous results, which showed that C99 is processed in the plasma membrane by α-secretase, in addition to the well-known γ-secretase. These findings suggest that C99 itself lacks an intrinsic affinity for raft domains, implying that either i) amyloidogenic processing of the protein occurs in disordered regions of the membrane, ii) processing involves a marginal subpopulation of C99 found in rafts, or iii) as-yet-unidentified protein-protein interactions with C99 in living cells drive this protein into membrane rafts to promote its cleavage therein.
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Affiliation(s)
- Ricardo Capone
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA; Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Ajit Tiwari
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | | | - Yelena Peskova
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, Virginia, USA
| | - James M Hutchison
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Charles R Sanders
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA; Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, USA; Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Anne K Kenworthy
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA.
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15
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Cenini G, Hebisch M, Iefremova V, Flitsch LJ, Breitkreuz Y, Tanzi RE, Kim DY, Peitz M, Brüstle O. Dissecting Alzheimer's disease pathogenesis in human 2D and 3D models. Mol Cell Neurosci 2021; 110:103568. [DOI: 10.1016/j.mcn.2020.103568] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/30/2020] [Accepted: 10/12/2020] [Indexed: 02/06/2023] Open
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16
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Montesinos J, Pera M, Larrea D, Guardia‐Laguarta C, Agrawal RR, Velasco KR, Yun TD, Stavrovskaya IG, Xu Y, Koo SY, Snead AM, Sproul AA, Area‐Gomez E. The Alzheimer's disease-associated C99 fragment of APP regulates cellular cholesterol trafficking. EMBO J 2020; 39:e103791. [PMID: 32865299 PMCID: PMC7560219 DOI: 10.15252/embj.2019103791] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 07/14/2020] [Accepted: 07/22/2020] [Indexed: 12/13/2022] Open
Abstract
The link between cholesterol homeostasis and cleavage of the amyloid precursor protein (APP), and how this relationship relates to Alzheimer's disease (AD) pathogenesis, is still unknown. Cellular cholesterol levels are regulated through crosstalk between the plasma membrane (PM), where most cellular cholesterol resides, and the endoplasmic reticulum (ER), where the protein machinery that regulates cholesterol levels resides. The intracellular transport of cholesterol from the PM to the ER is believed to be activated by a lipid-sensing peptide(s) in the ER that can cluster PM-derived cholesterol into transient detergent-resistant membrane domains (DRMs) within the ER, also called the ER regulatory pool of cholesterol. When formed, these cholesterol-rich domains in the ER maintain cellular homeostasis by inducing cholesterol esterification as a mechanism of detoxification while attenuating its de novo synthesis. In this manuscript, we propose that the 99-aa C-terminal fragment of APP (C99), when delivered to the ER for cleavage by γ-secretase, acts as a lipid-sensing peptide that forms regulatory DRMs in the ER, called mitochondria-associated ER membranes (MAM). Our data in cellular AD models indicates that increased levels of uncleaved C99 in the ER, an early phenotype of the disease, upregulates the formation of these transient DRMs by inducing the internalization of extracellular cholesterol and its trafficking from the PM to the ER. These results suggest a novel role for C99 as a mediator of cholesterol disturbances in AD, potentially explaining early hallmarks of the disease.
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Affiliation(s)
- Jorge Montesinos
- Department of NeurologyColumbia University Irving Medical CenterNew YorkNYUSA
| | - Marta Pera
- Department of NeurologyColumbia University Irving Medical CenterNew YorkNYUSA
- Present address:
Basic Sciences DepartmentFaculty of Medicine and Health SciencesUniversitat Internacional de CatalunyaBarcelonaSpain
| | - Delfina Larrea
- Department of NeurologyColumbia University Irving Medical CenterNew YorkNYUSA
| | | | - Rishi R Agrawal
- Institute of Human NutritionColumbia University Irving Medical CenterNew YorkNYUSA
| | - Kevin R Velasco
- Department of NeurologyColumbia University Irving Medical CenterNew YorkNYUSA
| | - Taekyung D Yun
- Department of NeurologyColumbia University Irving Medical CenterNew YorkNYUSA
| | | | - Yimeng Xu
- Biomarkers Core LaboratoryColumbia University Irving Medical CenterNew YorkNYUSA
| | - So Yeon Koo
- Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia University Irving Medical CenterNew YorkNYUSA
| | - Amanda M Snead
- Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia University Irving Medical CenterNew YorkNYUSA
| | - Andrew A Sproul
- Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia University Irving Medical CenterNew YorkNYUSA
- Department of Pathology and Cell BiologyColumbia University Irving Medical CenterNew YorkNYUSA
| | - Estela Area‐Gomez
- Department of NeurologyColumbia University Irving Medical CenterNew YorkNYUSA
- Institute of Human NutritionColumbia University Irving Medical CenterNew YorkNYUSA
- Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia University Irving Medical CenterNew YorkNYUSA
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17
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Wang J, Ling R, Zhou Y, Gao X, Yang Y, Mao C, Chen D. SREBP1 silencing inhibits the proliferation and motility of human esophageal squamous carcinoma cells via the Wnt/β-catenin signaling pathway. Oncol Lett 2020; 20:2855-2869. [PMID: 32765792 PMCID: PMC7403634 DOI: 10.3892/ol.2020.11853] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 05/22/2020] [Indexed: 12/24/2022] Open
Abstract
Sterol regulatory element-binding protein 1 (SREBP1) is dysregulated in a variety of types of human cancer. However, the functional roles of SREBP1 in esophageal squamous cell carcinoma (ESCC) remain poorly understood. The present study investigated the function of SREBP1 in cell proliferation and motility. Microarray datasets in Oncomine, reverse transcription-quantitative PCR and western blot analysis revealed that SREBP1 was overexpressed in ESCC tumors when compared with normal tissues. In addition, SREBP1 overexpression was significantly associated with tumor differentiation, lymphatic metastasis and Ki67 expression. Results suggested that silencing SREBP1 inhibited the proliferation, migration and invasion of ESCC cells, whereas overexpression of SREBP1 had opposite effects on proliferation and metastasis. In addition, loss of SREBP1 significantly increased E-cadherin and decreased N-cadherin, Vimentin, Snail, matrix metalloproteinase 9 and vascular endothelial growth factor C expression levels, which were restored via SREBP1-overexpression. Mechanistically, loss of SREBP1 suppressed T-cell factor 1/lymphoid enhancer factor 1 (TCF1/LEF1) activity and downregulated TCF1/LEF1 target proteins, including CD44 and cyclin D1. Moreover, knockdown of SREBP1 downregulated the expression levels of stearoyl-CoA desaturase 1 (SCD1), phosphorylated glycogen synthase kinase-3β and nuclear β-catenin. Furthermore, the inhibitors of SREBP1 and/or SCD1 and small interfering RNA-SCD1 efficiently inhibited the activation of the Wnt/β-catenin pathway driven by constitutively active SREBP1. Finally, in vivo results indicated that SREBP1-knockdown suppressed the proliferation and metastasis of ESCC. Taken together, these findings demonstrated that SREBP1 exerts oncogenic effects in ESCC by promoting proliferation and inducing epithelial-mesenchymal transition via the SCD1-induced activation of the Wnt/β-catenin signaling pathway.
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Affiliation(s)
- Jingzhi Wang
- Institute of Oncology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China
| | - Rui Ling
- Institute of Oncology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China
| | - Yuepeng Zhou
- Institute of Oncology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China
| | - Xingyu Gao
- Institute of Oncology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China
| | - Yun Yang
- Institute of Oncology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China
| | - Chaoming Mao
- Institute of Oncology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China.,Department of Nuclear Medicine, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China
| | - Deyu Chen
- Institute of Oncology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China
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18
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Amyloid Precursor Protein (APP) Controls the Expression of the Transcriptional Activator Neuronal PAS Domain Protein 4 (NPAS4) and Synaptic GABA Release. eNeuro 2020; 7:ENEURO.0322-19.2020. [PMID: 32327470 PMCID: PMC7262005 DOI: 10.1523/eneuro.0322-19.2020] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 03/13/2020] [Accepted: 03/17/2020] [Indexed: 12/11/2022] Open
Abstract
The amyloid precursor protein (APP) has been extensively studied as the precursor of the β-amyloid (Aβ) peptide, the major component of the senile plaques found in the brain of Alzheimer’s disease (AD) patients. However, the function of APP per se in neuronal physiology remains to be fully elucidated. APP is expressed at high levels in the brain. It resembles a cell adhesion molecule or a membrane receptor, suggesting that its function relies on cell-cell interaction and/or activation of intracellular signaling pathways. In this respect, the APP intracellular domain (AICD) was reported to act as a transcriptional regulator. Here, we used a transcriptome-based approach to identify the genes transcriptionally regulated by APP in the rodent embryonic cortex and on maturation of primary cortical neurons. Surprisingly, the overall transcriptional changes were subtle, but a more detailed analysis pointed to genes clustered in neuronal-activity dependent pathways. In particular, we observed a decreased transcription of neuronal PAS domain protein 4 (NPAS4) in APP−/− neurons. NPAS4 is an inducible transcription factor (ITF) regulated by neuronal depolarization. The downregulation of NPAS4 co-occurs with an increased production of the inhibitory neurotransmitter GABA and a reduced expression of the GABAA receptors α1. CRISPR-Cas-mediated silencing of NPAS4 in neurons led to similar observations. Patch-clamp investigation did not reveal any functional decrease of GABAA receptors activity, but long-term potentiation (LTP) measurement supported an increased GABA component in synaptic transmission of APP−/− mice. Together, NPAS4 appears to be a downstream target involved in APP-dependent regulation of inhibitory synaptic transmission.
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19
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Sáez-Orellana F, Octave JN, Pierrot N. Alzheimer's Disease, a Lipid Story: Involvement of Peroxisome Proliferator-Activated Receptor α. Cells 2020; 9:E1215. [PMID: 32422896 PMCID: PMC7290654 DOI: 10.3390/cells9051215] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/10/2020] [Accepted: 05/12/2020] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) is the leading cause of dementia in the elderly. Mutations in genes encoding proteins involved in amyloid-β peptide (Aβ) production are responsible for inherited AD cases. The amyloid cascade hypothesis was proposed to explain the pathogeny. Despite the fact that Aβ is considered as the main culprit of the pathology, most clinical trials focusing on Aβ failed and suggested that earlier interventions are needed to influence the course of AD. Therefore, identifying risk factors that predispose to AD is crucial. Among them, the epsilon 4 allele of the apolipoprotein E gene that encodes the major brain lipid carrier and metabolic disorders such as obesity and type 2 diabetes were identified as AD risk factors, suggesting that abnormal lipid metabolism could influence the progression of the disease. Among lipids, fatty acids (FAs) play a fundamental role in proper brain function, including memory. Peroxisome proliferator-activated receptor α (PPARα) is a master metabolic regulator that regulates the catabolism of FA. Several studies report an essential role of PPARα in neuronal function governing synaptic plasticity and cognition. In this review, we explore the implication of lipid metabolism in AD, with a special focus on PPARα and its potential role in AD therapy.
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Affiliation(s)
- Francisco Sáez-Orellana
- Université Catholique de Louvain, Alzheimer Dementia, Avenue Mounier 53, SSS/IONS/CEMO-Bte B1.53.03, B-1200 Brussels, Belgium; (F.S.-O.); (J.-N.O.)
- Institute of Neuroscience, Alzheimer Dementia, Avenue Mounier 53, SSS/IONS/CEMO-Bte B1.53.03, B-1200 Brussels, Belgium
| | - Jean-Noël Octave
- Université Catholique de Louvain, Alzheimer Dementia, Avenue Mounier 53, SSS/IONS/CEMO-Bte B1.53.03, B-1200 Brussels, Belgium; (F.S.-O.); (J.-N.O.)
- Institute of Neuroscience, Alzheimer Dementia, Avenue Mounier 53, SSS/IONS/CEMO-Bte B1.53.03, B-1200 Brussels, Belgium
| | - Nathalie Pierrot
- Université Catholique de Louvain, Alzheimer Dementia, Avenue Mounier 53, SSS/IONS/CEMO-Bte B1.53.03, B-1200 Brussels, Belgium; (F.S.-O.); (J.-N.O.)
- Institute of Neuroscience, Alzheimer Dementia, Avenue Mounier 53, SSS/IONS/CEMO-Bte B1.53.03, B-1200 Brussels, Belgium
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20
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Hicks D, Jones A, Pickering-Brown S, Hooper N. The cellular expression and proteolytic processing of the amyloid precursor protein is independent of TDP-43. Biosci Rep 2020; 40:BSR20200435. [PMID: 32301481 PMCID: PMC7189496 DOI: 10.1042/bsr20200435] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/03/2020] [Accepted: 04/06/2020] [Indexed: 02/07/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative condition, of which one of the cardinal pathological hallmarks is the extracellular accumulation of amyloid β (Aβ) peptides. These peptides are generated via proteolysis of the amyloid precursor protein (APP), in a manner dependent on the β-secretase, BACE1 and the multicomponent γ-secretase complex. Recent data also suggest a contributory role in AD of transactive response DNA binding protein 43 (TDP-43). There is little insight into a possible mechanism linking TDP-43 and APP processing. To this end, we used cultured human neuronal cells to investigate the ability of TDP-43 to interact with APP and modulate its proteolytic processing. Immunocytochemistry showed TDP-43 to be spatially segregated from both the extranuclear APP holoprotein and its nuclear C-terminal fragment. The latter (APP intracellular domain) was shown to predominantly localise to nucleoli, from which TDP-43 was excluded. Furthermore, neither overexpression of each of the APP isoforms nor siRNA-mediated knockdown of APP had any effect on TDP-43 expression. Doxycycline-stimulated overexpression of TDP-43 was explored in an inducible cell line. Overexpression of TDP-43 had no effect on expression of the APP holoprotein, nor any of the key proteins involved in its proteolysis. Furthermore, increased TDP-43 expression had no effect on BACE1 enzymatic activity or immunoreactivity of Aβ1-40, Aβ1-42 or the Aβ1-40:Aβ1-42 ratio. Also, siRNA-mediated knockdown of TDP-43 had no effect on BACE1 immunoreactivity. Taken together, these data indicate that TDP-43 function and/or dysfunction in AD is likely independent from dysregulation of APP expression and proteolytic processing and Aβ generation.
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Affiliation(s)
- David A. Hicks
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, M13 9PT, United Kingdom
| | - Alys C. Jones
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, M13 9PT, United Kingdom
| | - Stuart M. Pickering-Brown
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, M13 9PT, United Kingdom
| | - Nigel M. Hooper
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, M13 9PT, United Kingdom
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21
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Gutierrez E, Lütjohann D, Kerksiek A, Fabiano M, Oikawa N, Kuerschner L, Thiele C, Walter J. Importance of γ-secretase in the regulation of liver X receptor and cellular lipid metabolism. Life Sci Alliance 2020; 3:3/6/e201900521. [PMID: 32354700 PMCID: PMC7195048 DOI: 10.26508/lsa.201900521] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 04/16/2020] [Accepted: 04/17/2020] [Indexed: 12/12/2022] Open
Abstract
Inhibition of the Alzheimer associated γ-secretase impairs the regulation of cellular lipid droplet homeostasis. Presenilins (PS) are the catalytic components of γ-secretase complexes that mediate intramembrane proteolysis. Mutations in the PS genes are a major cause of familial early-onset Alzheimer disease and affect the cleavage of the amyloid precursor protein, thereby altering the production of the amyloid β-peptide. However, multiple additional protein substrates have been identified, suggesting pleiotropic functions of γ-secretase. Here, we demonstrate that inhibition of γ-secretase causes dysregulation of cellular lipid homeostasis, including up-regulation of liver X receptors, and complex changes in the cellular lipid composition. Genetic and pharmacological inhibition of γsecretase leads to strong accumulation of cytoplasmic lipid droplets, associated with increased levels of acylglycerols, but lowered cholesteryl esters. Furthermore, accumulation of lipid droplets was augmented by increasing levels of amyloid precursor protein C-terminal fragments, indicating a critical involvement of this γ-secretase substrate. Together, these data provide a mechanism that functionally connects γ-secretase activity to cellular lipid metabolism. These effects were also observed in human astrocytic cells, indicating an important function of γ-secretase in cells critical for lipid homeostasis in the brain.
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Affiliation(s)
| | - Dieter Lütjohann
- Institute of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Bonn, Germany
| | - Anja Kerksiek
- Institute of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Bonn, Germany
| | - Marietta Fabiano
- Department of Neurology, University Hospital Bonn, Bonn, Germany
| | - Naoto Oikawa
- Department of Neurology, University Hospital Bonn, Bonn, Germany
| | - Lars Kuerschner
- Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Christoph Thiele
- Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Jochen Walter
- Department of Neurology, University Hospital Bonn, Bonn, Germany
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22
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Pająk B, Kania E, Gołaszewska A, Orzechowski A. Preliminary Study on Clusterin Protein (sCLU) Expression in PC-12 Cells Overexpressing Wild-Type and Mutated (Swedish) AβPP genes Affected by Non-Steroid Isoprenoids and Water-Soluble Cholesterol. Int J Mol Sci 2019; 20:E1481. [PMID: 30909654 PMCID: PMC6470582 DOI: 10.3390/ijms20061481] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 03/04/2019] [Accepted: 03/18/2019] [Indexed: 02/07/2023] Open
Abstract
In this study we attempted to verify the hypothesis that the mevalonate pathway affects amyloid beta precursor protein (AβPP) processing and regulates clusterin protein levels. AβPP expression was monitored by green fluorescence (FL) and Western blot (WB). WB showed soluble amyloid protein precursor alpha (sAβPPα) presence in AβPP-wt cells and Aβ expression in AβPP-sw cells. Nerve growth factor (NGF)-differentiated rat neuronal pheochromocytoma PC-12 cells were untreated/treated with statins alone or together with non-sterol isoprenoids. Co-treatment with mevalonate, dolichol, ubiquinol, farnesol, geranylgeraniol, or water-soluble cholesterol demonstrated statin-dependent neurotoxicity resulted from the attenuated activity of mevalonate pathway rather than lower cholesterol level. Atorvastatin (50 μM) or simvastatin (50 μM) as well as cholesterol chelator methyl-β-cyclodextrin (0.2 mM) diminished cell viability (p < 0.05) and clusterin levels. Interestingly, co-treatment with mevalonate, dolichol, ubiquinol, farnesol, geranylgeraniol, or water-soluble cholesterol stimulated (p < 0.05) clusterin expression. Effects of non-sterol isoprenoids, but not water soluble cholesterol (Chol-PEG), were the most significant in mock-transfected cells. Geranylgeraniol (GGOH) overcame atorvastatin (ATR)-dependent cytotoxicity. This effect does not seem to be dependent on clusterin, as its level became lower after GGOH. The novelty of these findings is that they show that the mevalonate (MEV) pathway rather than cholesterol itself plays an important role in clusterin expression levels. In mock-transfected, rather than in AβPP-overexpressing cells, GGOH/farnesol (FOH) exerted a protective effect. Thus, protein prenylation with GGOH/FOH might play substantial role in neuronal cell survival.
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Affiliation(s)
- Beata Pająk
- Independent Laboratory of Genetics and Molecular Biology, Kaczkowski Military Institute of Hygiene and Epidemiology, Kozielska 4, 01-163 Warsaw, Poland.
| | - Elżbieta Kania
- Tumor Cell Death Laboratory, Cancer Research UK, Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK.
| | - Anita Gołaszewska
- Department of Neuroendocrinology, Centre of Postgraduate Medical Education, Marymoncka 99/103, 01-813 Warsaw, Poland.
- Department of Physiological Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences ⁻ SGGW, Nowoursynowska 159, 02-776 Warsaw, Poland.
| | - Arkadiusz Orzechowski
- Department of Physiological Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences ⁻ SGGW, Nowoursynowska 159, 02-776 Warsaw, Poland.
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23
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Pierrot N, Ris L, Stancu IC, Doshina A, Ribeiro F, Tyteca D, Baugé E, Lalloyer F, Malong L, Schakman O, Leroy K, Kienlen-Campard P, Gailly P, Brion JP, Dewachter I, Staels B, Octave JN. Sex-regulated gene dosage effect of PPARα on synaptic plasticity. Life Sci Alliance 2019; 2:2/2/e201800262. [PMID: 30894406 PMCID: PMC6427998 DOI: 10.26508/lsa.201800262] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/01/2019] [Accepted: 03/11/2019] [Indexed: 12/13/2022] Open
Abstract
Differences in PPARα expression between males and females affect the regulation of GluA1 expression and synaptic plasticity in mice. Mechanisms driving cognitive improvements following nuclear receptor activation are poorly understood. The peroxisome proliferator–activated nuclear receptor alpha (PPARα) forms heterodimers with the nuclear retinoid X receptor (RXR). We report that PPARα mediates the improvement of hippocampal synaptic plasticity upon RXR activation in a transgenic mouse model with cognitive deficits. This improvement results from an increase in GluA1 subunit expression of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor, eliciting an AMPA response at the excitatory synapses. Associated with a two times higher PPARα expression in males than in females, we show that male, but not female, PPARα null mutants display impaired hippocampal long-term potentiation. Moreover, PPARα knockdown in the hippocampus of cognition-impaired mice compromises the beneficial effects of RXR activation on synaptic plasticity only in males. Furthermore, selective PPARα activation with pemafibrate improves synaptic plasticity in male cognition-impaired mice, but not in females. We conclude that striking sex differences in hippocampal synaptic plasticity are observed in mice, related to differences in PPARα expression levels.
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Affiliation(s)
- Nathalie Pierrot
- Université Catholique de Louvain, Brussels, Belgium .,Institute of Neuroscience, Brussels, Belgium
| | - Laurence Ris
- Laboratory of Neuroscience, Health Institute, University of Mons, Mons, Belgium
| | - Ilie-Cosmin Stancu
- Université Catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium.,Biomedical Research Institute, Hasselt University, Hasselt, Belgium
| | - Anna Doshina
- Université Catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium
| | - Floriane Ribeiro
- Université Catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium
| | - Donatienne Tyteca
- Université Catholique de Louvain, Brussels, Belgium.,de Duve Institute, Brussels, Belgium
| | - Eric Baugé
- Université de Lille EGID, Inserm, CHU Lille, Institut Pasteur de Lille, Lille, France
| | - Fanny Lalloyer
- Université de Lille EGID, Inserm, CHU Lille, Institut Pasteur de Lille, Lille, France
| | - Liza Malong
- Université Catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium
| | - Olivier Schakman
- Université Catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium
| | - Karelle Leroy
- Laboratory of Histology and Neuropathology, Université Libre de Bruxelles, Brussels, Belgium
| | - Pascal Kienlen-Campard
- Université Catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium
| | - Philippe Gailly
- Université Catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium
| | - Jean-Pierre Brion
- Laboratory of Histology and Neuropathology, Université Libre de Bruxelles, Brussels, Belgium
| | - Ilse Dewachter
- Université Catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium.,Biomedical Research Institute, Hasselt University, Hasselt, Belgium
| | - Bart Staels
- Université de Lille EGID, Inserm, CHU Lille, Institut Pasteur de Lille, Lille, France
| | - Jean-Noël Octave
- Université Catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium
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24
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Reciprocal modulation between amyloid precursor protein and synaptic membrane cholesterol revealed by live cell imaging. Neurobiol Dis 2019; 127:449-461. [PMID: 30885793 DOI: 10.1016/j.nbd.2019.03.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 02/03/2019] [Accepted: 03/12/2019] [Indexed: 12/20/2022] Open
Abstract
The amyloid precursor protein (APP) has been extensively studied because of its association with Alzheimer's disease (AD). However, APP distribution across different subcellular membrane compartments and its function in neurons remains unclear. We generated an APP fusion protein with a pH-sensitive green fluorescent protein at its ectodomain and a pH-insensitive blue fluorescent protein at its cytosolic domain and used it to measure APP's distribution, subcellular trafficking, and cleavage in live neurons. This reporter, closely resembling endogenous APP, revealed only a limited correlation between synaptic activities and APP trafficking. However, the synaptic surface fraction of APP was increased by a reduction in membrane cholesterol levels, a phenomenon that involves APP's cholesterol-binding motif. Mutations at or near binding sites not only reduced both the surface fraction of APP and membrane cholesterol levels in a dominant negative manner, but also increased synaptic vulnerability to moderate membrane cholesterol reduction. Our results reveal reciprocal modulation of APP and membrane cholesterol levels at synaptic boutons.
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25
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Lou F, Li M, Liu N, Li X, Ren Y, Luo X. The polymorphism of SREBF1 gene rs11868035 G/A is associated with susceptibility to Parkinson’s disease in a Chinese population. Int J Neurosci 2019; 129:660-665. [PMID: 30231795 DOI: 10.1080/00207454.2018.1526796] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Fan Lou
- Department of Neurology, First Affiliated Hospital of China Medical University, Shenyang, PR China
| | - Ming Li
- Department of Neurology, The Fourth Affiliated Hospital of China Medical University, Shenyang, PR China
| | - Na Liu
- Department of Neurology, First Affiliated Hospital of China Medical University, Shenyang, PR China
| | - Xiaohong Li
- Department of Neurology, First Affiliated Hospital of China Medical University, Shenyang, PR China
| | - Yan Ren
- Department of Neurology, First Affiliated Hospital of China Medical University, Shenyang, PR China
| | - Xiaoguang Luo
- Department of Neurology, First Affiliated Hospital of China Medical University, Shenyang, PR China
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26
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Wang C, Zhao F, Shen K, Wang W, Siedlak SL, Lee HG, Phelix CF, Perry G, Shen L, Tang B, Yan R, Zhu X. The sterol regulatory element-binding protein 2 is dysregulated by tau alterations in Alzheimer disease. Brain Pathol 2019; 29:530-543. [PMID: 30515907 DOI: 10.1111/bpa.12691] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 11/28/2018] [Indexed: 01/12/2023] Open
Abstract
Disturbed neuronal cholesterol homeostasis has been observed in Alzheimer disease (AD) and contributes to the pathogenesis of AD. As the master switch of cholesterol biosynthesis, the sterol regulatory element-binding protein 2 (SREBP-2) translocates to the nucleus after cleavage/activation, but its expression and activation have not been studied in AD which is the focus of the current study. We found both a significant decrease in the nuclear translocation of N-terminal SREBP-2 accompanied by a significant accumulation of C-terminal SREBP-2 in NFT-containing pyramidal neurons in AD. N-terminal- SREBP-2 is also found in dystrophic neurites around plaques in AD brain. Western blot confirmed a significantly reduced nuclear translocation of mature SREBP-2 (mSREBP-2) in AD brain. Interestingly, reduced nuclear mSREBP-2 was only found in animal models of tauopathies such as 3XTg AD mice and P301L Tau Tg mice but not in CRND8 APP transgenic mice, suggesting that tau alterations likely are involved in the changes of mSREBP-2 distribution and activation in AD. Altogether, our study demonstrated disturbed SREBP-2 signaling in AD and related models, and proved for the first time that tau alterations contribute to disturbed cholesterol homeostasis in AD likely through modulation of nuclear mSREBP-2 translocation.
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Affiliation(s)
- Chunyu Wang
- Department of Neurology, The second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China.,Department of Pathology, Case Western Reserve University, Cleveland, OH
| | - Fanpeng Zhao
- Department of Pathology, Case Western Reserve University, Cleveland, OH
| | - Katie Shen
- Department of Pathology, Case Western Reserve University, Cleveland, OH
| | - Wenzhang Wang
- Department of Pathology, Case Western Reserve University, Cleveland, OH
| | - Sandra L Siedlak
- Department of Pathology, Case Western Reserve University, Cleveland, OH
| | - Hyoung-Gon Lee
- Department of Biology, College of Science, University of Texas at San Antonio, San Antonio, TX
| | - Clyde F Phelix
- Department of Biology, College of Science, University of Texas at San Antonio, San Antonio, TX
| | - George Perry
- Department of Biology, College of Science, University of Texas at San Antonio, San Antonio, TX
| | - Lu Shen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Riqiang Yan
- Department of Neurosciences, University of Connecticut, Farmington, CT
| | - Xiongwei Zhu
- Department of Pathology, Case Western Reserve University, Cleveland, OH
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27
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Li CD, Junaid M, Chen H, Ali A, Wei DQ. Helix-Switch Enables C99 Dimer Transition between the Multiple Conformations. J Chem Inf Model 2019; 59:339-350. [PMID: 30570254 DOI: 10.1021/acs.jcim.8b00559] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
C99 is the immediate precursor of amyloid-β (Aβ) and therefore is a central intermediate in the pathway that is believed to result in Alzheimer's disease (AD). Recent studies have shown that C99 dimerization changes the Aβ ratio, but the mechanism remains unclear. Previous studies of the C99 dimer have produced controversial structure models. To address these questions, we investigated C99 dimerization using molecular dynamics (MD) simulations. A helix-switch model was revealed in the formation and transition of the C99 dimer, and six types of conformations were identified. The different conformations show differential exposures of γ-cleavage sites and insertion depths in the bilayer, which may modulate γ-cleavage of C99 and lead to different Aβ levels. Our results redefine C99 dimerization, provide a framework to mediate the current controversial results, and give insights into the understanding of the relationship between C99 dimerization and Aβ formation.
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Affiliation(s)
- Cheng-Dong Li
- State Key Laboratory of Microbial Metabolism and College of Life Sciences and Biotechnology , Shanghai Jiao Tong University , Minhang District, Shanghai 200240 , China.,Department of Mechanical Engineering and Material Science , Yale University , New Haven , Connecticut 06520-8286 , United States
| | - Muhammad Junaid
- State Key Laboratory of Microbial Metabolism and College of Life Sciences and Biotechnology , Shanghai Jiao Tong University , Minhang District, Shanghai 200240 , China
| | - Hui Chen
- State Key Laboratory of Microbial Metabolism and College of Life Sciences and Biotechnology , Shanghai Jiao Tong University , Minhang District, Shanghai 200240 , China
| | - Arif Ali
- State Key Laboratory of Microbial Metabolism and College of Life Sciences and Biotechnology , Shanghai Jiao Tong University , Minhang District, Shanghai 200240 , China
| | - Dong-Qing Wei
- State Key Laboratory of Microbial Metabolism and College of Life Sciences and Biotechnology , Shanghai Jiao Tong University , Minhang District, Shanghai 200240 , China
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28
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DelBove CE, Deng XZ, Zhang Q. The Fate of Nascent APP in Hippocampal Neurons: A Live Cell Imaging Study. ACS Chem Neurosci 2018; 9:2225-2232. [PMID: 29869871 DOI: 10.1021/acschemneuro.8b00226] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Amyloid precursor protein (APP) is closely associated with Alzheimer's disease (AD) because its proteolytic products form amyloid plaques and its mutations are linked to familial AD patients. As a membrane protein, APP is involved in neuronal development and plasticity. However, it remains unclear how nascent APP is distributed and transported to designated membrane compartments to execute its diverse functions. Here, we employed a dual-tagged APP fusion protein in combination with a synaptic vesicle marker to study the surface trafficking and cleavage of APP in hippocampal neurons immediately after its synthesis. Using long-term time-lapse imaging, we found that a considerable amount of nascent APP was directly transported to the somatodendritic surface, from which it propagates to distal neurites. Some APP in the plasma membrane was endocytosed and some was cleaved by α-secretase. Hence, we conclude that surface transportation of APP is a major step preceding its proteolytic processing and neuritic distribution.
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Affiliation(s)
- Claire E. DelBove
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232-6600, United States
| | - Xian-zhen Deng
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232-6600, United States
| | - Qi Zhang
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232-6600, United States
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29
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Paschkowsky S, Recinto SJ, Young JC, Bondar AN, Munter LM. Membrane cholesterol as regulator of human rhomboid protease RHBDL4. J Biol Chem 2018; 293:15556-15568. [PMID: 30143535 DOI: 10.1074/jbc.ra118.002640] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 08/18/2018] [Indexed: 12/28/2022] Open
Abstract
In the last decade, intramembrane proteases have gained increasing attention because of their many links to various diseases. Nevertheless, our understanding as to how they function or how they are regulated is still limited, especially when it comes to human homologues. In this regard, here we sought to unravel mechanisms of regulation of the protease rhomboid-like protein-4 (RHBDL4), one of five active human serine intramembrane proteases. In view of our recent finding that human RHBDL4 efficiently cleaves the amyloid precursor protein (APP), a key protein in the pathology of Alzheimer's disease, we used established reagents to modulate the cellular cholesterol content and analyzed the effects of this modulation on RHBDL4-mediated processing of endogenous APP. We discovered that lowering membrane cholesterol levels increased the levels of RHBDL4-specific endogenous APP fragments, whereas high cholesterol levels had the opposite effect. Direct binding of cholesterol to APP did not mediate these modulating effects of cholesterol. Instead, using homology modeling, we identified two potential cholesterol-binding motifs in the transmembrane helices 3 and 6 of RHBDL4. Substitution of the essential tyrosine residues of the potential cholesterol-binding motifs to alanine increased the levels of endogenous APP C-terminal fragments, reflecting enhanced RHBDL4 activity. In summary, we provide evidence that the activity of RHBDL4 is regulated by cholesterol likely through a direct binding of cholesterol to the enzyme.
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Affiliation(s)
- Sandra Paschkowsky
- From the Department of Pharmacology and Therapeutics and Cell Information Systems Group and
| | | | - Jason C Young
- Department of Biochemistry and Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec H3G 0B1, Canada and
| | - Ana-Nicoleta Bondar
- the Department of Physics, Theoretical Molecular Biophysics, Freie Universität Berlin, Arnimallee 14, Berlin 14195, Germany
| | - Lisa Marie Munter
- From the Department of Pharmacology and Therapeutics and Cell Information Systems Group and
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30
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Fong LK, Yang MM, Dos Santos Chaves R, Reyna SM, Langness VF, Woodruff G, Roberts EA, Young JE, Goldstein LSB. Full-length amyloid precursor protein regulates lipoprotein metabolism and amyloid-β clearance in human astrocytes. J Biol Chem 2018; 293:11341-11357. [PMID: 29858247 DOI: 10.1074/jbc.ra117.000441] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 05/11/2018] [Indexed: 02/05/2023] Open
Abstract
Mounting evidence suggests that alterations in cholesterol homeostasis are involved in Alzheimer's disease (AD) pathogenesis. Amyloid precursor protein (APP) or multiple fragments generated by proteolytic processing of APP have previously been implicated in the regulation of cholesterol metabolism. However, the physiological function of APP in regulating lipoprotein homeostasis in astrocytes, which are responsible for de novo cholesterol biosynthesis and regulation in the brain, remains unclear. To address this, here we used CRISPR/Cas9 genome editing to generate isogenic APP-knockout (KO) human induced pluripotent stem cells (hiPSCs) and differentiated them into human astrocytes. We found that APP-KO astrocytes have reduced cholesterol and elevated levels of sterol regulatory element-binding protein (SREBP) target gene transcripts and proteins, which were both downstream consequences of reduced lipoprotein endocytosis. To elucidate which APP fragments regulate cholesterol homeostasis and to examine whether familial AD mutations in APP affect lipoprotein metabolism, we analyzed an isogenic allelic series harboring the APP Swedish and APP V717F variants. Only astrocytes homozygous for the APP Swedish (APPSwe/Swe) mutation, which had reduced full-length APP (FL APP) due to increased β-secretase cleavage, recapitulated the APP-KO phenotypes. Astrocytic internalization of β-amyloid (Aβ), another ligand for low-density lipoprotein (LDL) receptors, was also impaired in APP-KO and APPSwe/Swe astrocytes. Finally, impairing cleavage of FL APP through β-secretase inhibition in APPSwe/Swe astrocytes reversed the LDL and Aβ endocytosis defects. In conclusion, FL APP is involved in the endocytosis of LDL receptor ligands and is required for proper cholesterol homeostasis and Aβ clearance in human astrocytes.
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Affiliation(s)
- Lauren K Fong
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093; Sanford Consortium for Regenerative Medicine, La Jolla, California 92093
| | - Max M Yang
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093; Sanford Consortium for Regenerative Medicine, La Jolla, California 92093
| | - Rodrigo Dos Santos Chaves
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093; Sanford Consortium for Regenerative Medicine, La Jolla, California 92093
| | - Sol M Reyna
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093; Sanford Consortium for Regenerative Medicine, La Jolla, California 92093
| | - Vanessa F Langness
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093; Sanford Consortium for Regenerative Medicine, La Jolla, California 92093
| | - Grace Woodruff
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093; Sanford Consortium for Regenerative Medicine, La Jolla, California 92093
| | - Elizabeth A Roberts
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093; Sanford Consortium for Regenerative Medicine, La Jolla, California 92093
| | - Jessica E Young
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093; Department of Pathology and Institute of Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington 98195
| | - Lawrence S B Goldstein
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093; Sanford Consortium for Regenerative Medicine, La Jolla, California 92093; Department of Neurosciences, University of California at San Diego, La Jolla, California 92093.
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31
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Endosomal-Lysosomal Cholesterol Sequestration by U18666A Differentially Regulates Amyloid Precursor Protein (APP) Metabolism in Normal and APP-Overexpressing Cells. Mol Cell Biol 2018. [PMID: 29530923 DOI: 10.1128/mcb.00529-17] [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: 01/05/2023] Open
Abstract
Amyloid β (Aβ) peptide, derived from amyloid precursor protein (APP), plays a critical role in the development of Alzheimer's disease. Current evidence indicates that altered levels or subcellular distribution of cholesterol can regulate Aβ production and clearance, but it remains unclear how cholesterol sequestration within the endosomal-lysosomal (EL) system can influence APP metabolism. Thus, we evaluated the effects of U18666A, which triggers cholesterol redistribution within the EL system, on mouse N2a cells expressing different levels of APP in the presence or absence of extracellular cholesterol and lipids provided by fetal bovine serum (FBS). Our results reveal that U18666A and FBS differentially increase the levels of APP and its cleaved products, the α-, β-, and η-C-terminal fragments, in N2a cells expressing normal levels of mouse APP (N2awt), higher levels of human wild-type APP (APPwt), or "Swedish" mutant APP (APPsw). The cellular levels of Aβ1-40/Aβ1-42 were markedly increased in U18666A-treated APPwt and APPsw cells. Our studies further demonstrate that APP and its cleaved products are partly accumulated in the lysosomes, possibly due to decreased clearance. Finally, we show that autophagy inhibition plays a role in mediating U18666A effects. Collectively, these results suggest that altered levels and distribution of cholesterol and lipids can differentially regulate APP metabolism depending on the nature of APP expression.
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32
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Pantelopulos GA, Straub JE, Thirumalai D, Sugita Y. Structure of APP-C99 1-99 and implications for role of extra-membrane domains in function and oligomerization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1698-1708. [PMID: 29702072 DOI: 10.1016/j.bbamem.2018.04.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 04/07/2018] [Accepted: 04/09/2018] [Indexed: 01/30/2023]
Abstract
The 99 amino acid C-terminal fragment of Amyloid Precursor Protein APP-C99 (C99) is cleaved by γ-secretase to form Aβ peptide, which plays a critical role in the etiology of Alzheimer's Disease (AD). The structure of C99 consists of a single transmembrane domain flanked by intra and intercellular domains. While the structure of the transmembrane domain has been well characterized, little is known about the structure of the flanking domains and their role in C99 processing by γ-secretase. To gain insight into the structure of full-length C99, REMD simulations were performed for monomeric C99 in model membranes of varying thickness. We find equilibrium ensembles of C99 from simulation agree with experimentally-inferred residue insertion depths and protein backbone chemical shifts. In thin membranes, the transmembrane domain structure is correlated with extra-membrane structural states and the extra-membrane domain structural states become less correlated to each other. Mean and variance of the transmembrane and G37G38 hinge angles are found to increase with thinning membrane. The N-terminus of C99 forms β-strands that may seed aggregation of Aβ on the membrane surface, promoting amyloid formation. In thicker membranes the N-terminus forms α-helices that interact with the nicastrin domain of γ-secretase. The C-terminus of C99 becomes more α-helical as the membrane thickens, forming structures that may be suitable for binding by cytoplasmic proteins, while C-terminal residues essential to cytotoxic function become α-helical as the membrane thins. The heterogeneous but discrete extra-membrane domain states analyzed here open the path to new investigations of the role of C99 structure and membrane in amyloidogenesis. This article is part of a Special Issue entitled: Protein Aggregation and Misfolding at the Cell Membrane Interface edited by Ayyalusamy Ramamoorthy.
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Affiliation(s)
- George A Pantelopulos
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, MA 02215-2521, USA
| | - John E Straub
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, MA 02215-2521, USA.
| | - D Thirumalai
- Department of Chemistry, The University of Texas, Austin, TX 78712-1224, USA
| | - Yuji Sugita
- Theoretical Molecular Science Laboratory, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
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33
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Binot C, Chouard CH. Neurodegenerative diseases, infectious pathologies and liquid crystals: Hypothesis of a common information vector involving a multidisciplinary approach. Rev Neurol (Paris) 2018; 174:540-554. [PMID: 29555421 DOI: 10.1016/j.neurol.2017.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 10/26/2017] [Accepted: 11/15/2017] [Indexed: 12/11/2022]
Abstract
The existence of an information vector common to very different pathologies is the hypothesis of one of us, the argumentation and discussion of which we present here. It is a mesomorphic state of material called liquid crystal. The liquid-ordered (Lo) phase, made up of membrane rafts mediated by cholesterol, lies at the center of our concept. This mesophase is either preexistent and then modified by the pathogenic process, or initiated by the latter. The most notable disorders involved are Alzheimer's, Parkinson's, Charcot and Creutzfeldt-Jakob diseases, flu-like illnesses and acquired immunodeficiency syndrome (AIDS), although this list may well be extended to include other anisotropic, birefringent amyloid proteinopathies, which have properties compatible with those of liquid crystals. Incidentally, numerous conventional infectious pathologies can also induce a mesomorphic state in cell membranes. It has already been established that mesophases contain the chemical information transmitted from the intramolecular microscopic level, where covalent bonds are applied. Information is then transmitted at the intermolecular macroscopic level, where it is made up of informed, self-organized collections. Electrostatic interactions, coordination of metallic ions, van der Waals forces and donor-acceptor interactions of hydrogen bonding all come into play. These reactions are produced notably in the nanodomains enriched by cholesterol and sphingolipids. Lipids in the cell membrane are where the phase separations favoring elastic hydrodynamic instabilities conducive to the Lo phase take place. In addition, perturbations of the mesomorphic states of membrane rafts due, for example, to lipid dysfunction-even mild ones-with an intracerebral or generalized location could bring about a displacement of thermodynamic equilibrium favoring the initiation and progression of the pathologies under consideration here. Indeed, the most recent work has rendered our hypothesis highly probable. Moreover, our hypothesis is supported by medical and biological observations arising essentially from biophysics and widely documented in the literature. Thus, these facts expand the number of diagnostic and therapeutic perspectives that could be evoked and perhaps even demand exploration.
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Affiliation(s)
- C Binot
- Bureau privé, rue de Terre-Neuve, 17410 Saint-Martin-de-Ré, France
| | - C-H Chouard
- Académie de médecine, 10, boulevard Flandrin, 75116 Paris, France.
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Ye R, Gordillo R, Shao M, Onodera T, Chen Z, Chen S, Lin X, SoRelle JA, Li X, Tang M, Keller MP, Kuliawat R, Attie AD, Gupta RK, Holland WL, Beutler B, Herz J, Scherer PE. Intracellular lipid metabolism impairs β cell compensation during diet-induced obesity. J Clin Invest 2018; 128:1178-1189. [PMID: 29457786 DOI: 10.1172/jci97702] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 01/09/2018] [Indexed: 12/16/2022] Open
Abstract
The compensatory proliferation of insulin-producing β cells is critical to maintaining glucose homeostasis at the early stage of type 2 diabetes. Failure of β cells to proliferate results in hyperglycemia and insulin dependence in patients. To understand the effect of the interplay between β cell compensation and lipid metabolism upon obesity and peripheral insulin resistance, we eliminated LDL receptor-related protein 1 (LRP1), a pleiotropic mediator of cholesterol, insulin, energy metabolism, and other cellular processes, in β cells. Upon high-fat diet exposure, LRP1 ablation significantly impaired insulin secretion and proliferation of β cells. The diminished insulin signaling was partly contributed to by the hypersensitivity to glucose-induced, Ca2+-dependent activation of Erk and the mTORC1 effector p85 S6K1. Surprisingly, in LRP1-deficient islets, lipotoxic sphingolipids were mitigated by improved lipid metabolism, mediated at least in part by the master transcriptional regulator PPARγ2. Acute overexpression of PPARγ2 in β cells impaired insulin signaling and insulin secretion. Elimination of Apbb2, a functional regulator of LRP1 cytoplasmic domain, also impaired β cell function in a similar fashion. In summary, our results uncover the double-edged effects of intracellular lipid metabolism on β cell function and viability in obesity and type 2 diabetes and highlight LRP1 as an essential regulator of these processes.
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Affiliation(s)
- Risheng Ye
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern (UTSW) Medical Center, Dallas, Texas, USA.,Department of Medical Education, Texas Tech University Health Sciences Center Paul L. Foster School of Medicine, El Paso, Texas, USA
| | - Ruth Gordillo
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern (UTSW) Medical Center, Dallas, Texas, USA
| | - Mengle Shao
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern (UTSW) Medical Center, Dallas, Texas, USA
| | - Toshiharu Onodera
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern (UTSW) Medical Center, Dallas, Texas, USA
| | - Zhe Chen
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern (UTSW) Medical Center, Dallas, Texas, USA.,Center for the Genetics of Host Defense, UTSW Medical Center, Dallas, Texas, USA
| | - Shiuhwei Chen
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern (UTSW) Medical Center, Dallas, Texas, USA
| | - Xiaoli Lin
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern (UTSW) Medical Center, Dallas, Texas, USA
| | - Jeffrey A SoRelle
- Center for the Genetics of Host Defense, UTSW Medical Center, Dallas, Texas, USA
| | - Xiaohong Li
- Center for the Genetics of Host Defense, UTSW Medical Center, Dallas, Texas, USA
| | - Miao Tang
- Center for the Genetics of Host Defense, UTSW Medical Center, Dallas, Texas, USA
| | - Mark P Keller
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Regina Kuliawat
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, New York, New York, USA
| | - Alan D Attie
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Rana K Gupta
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern (UTSW) Medical Center, Dallas, Texas, USA
| | - William L Holland
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern (UTSW) Medical Center, Dallas, Texas, USA
| | - Bruce Beutler
- Center for the Genetics of Host Defense, UTSW Medical Center, Dallas, Texas, USA
| | - Joachim Herz
- Departments of Molecular Genetics, Neuroscience, Neurology and Neurotherapeutics, and Center for Translational Neurodegeneration Research, UTSW Medical Center, Dallas, Texas, USA.,Center for Neuroscience, Department of Neuroanatomy, Albert Ludwig University, Freiburg, Germany
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern (UTSW) Medical Center, Dallas, Texas, USA
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35
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Frutos P, Toral P, Hervás G. Individual variation of the extent of milk fat depression in dairy ewes fed fish oil: Milk fatty acid profile and mRNA abundance of candidate genes involved in mammary lipogenesis. J Dairy Sci 2017; 100:9611-9622. [DOI: 10.3168/jds.2017-13354] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 08/19/2017] [Indexed: 12/27/2022]
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36
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Abstract
Cellular lipid metabolism and homeostasis are controlled by sterol regulatory-element binding proteins (SREBPs). In addition to performing canonical functions in the transcriptional regulation of genes involved in the biosynthesis and uptake of lipids, genome-wide system analyses have revealed that these versatile transcription factors act as important nodes of convergence and divergence within biological signalling networks. Thus, they are involved in myriad physiological and pathophysiological processes, highlighting the importance of lipid metabolism in biology. Changes in cell metabolism and growth are reciprocally linked through SREBPs. Anabolic and growth signalling pathways branch off and connect to multiple steps of SREBP activation and form complex regulatory networks. In addition, SREBPs are implicated in numerous pathogenic processes such as endoplasmic reticulum stress, inflammation, autophagy and apoptosis, and in this way, they contribute to obesity, dyslipidaemia, diabetes mellitus, nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, chronic kidney disease, neurodegenerative diseases and cancers. This Review aims to provide a comprehensive understanding of the role of SREBPs in physiology and pathophysiology at the cell, organ and organism levels.
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Affiliation(s)
- Hitoshi Shimano
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
- Life Science Center, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba 305-8577, Japan
- AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo 100-0004, Japan
| | - Ryuichiro Sato
- AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo 100-0004, Japan
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan
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37
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Mohamed A, Viveiros A, Williams K, Posse de Chaves E. Aβ inhibits SREBP-2 activation through Akt inhibition. J Lipid Res 2017; 59:1-13. [PMID: 29122977 PMCID: PMC5748492 DOI: 10.1194/jlr.m076703] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 10/21/2017] [Indexed: 12/20/2022] Open
Abstract
We previously demonstrated that oligomeric amyloid β42 (oAβ42) inhibits the mevalonate pathway impairing cholesterol synthesis and protein prenylation. Enzymes of the mevalonate pathway are regulated by the transcription factor SREBP-2. Here, we show that in several neuronal types challenged with oAβ42, SREBP-2 activation is reduced. Moreover, SREBP-2 activation is also decreased in the brain cortex of the Alzheimer's disease (AD) mouse model, TgCRND8, suggesting that SREBP-2 may be affected in vivo early in the disease. We demonstrate that oAβ42 does not affect enzymatic cleavage of SREBP-2 per se, but may impair SREBP-2 transport from the endoplasmic reticulum (ER) to the Golgi. Trafficking of SREBP-2 from the ER to the Golgi requires protein kinase B (Akt) activation. oAβ42 significantly reduces Akt phosphorylation and this decrease is responsible for the decline in SREBP-2 activation. Overexpression of constitutively active Akt prevents the effect of oAβ42 on SREBP-2 and the downstream inhibition of cholesterol synthesis and protein prenylation. Our work provides a novel mechanistic link between Aβ and the mevalonate pathway, which will impact the views on issues related to cholesterol, isoprenoids, and statins in AD. We also identify SREBP-2 as an indirect target of Akt in neurons, which may play a role in the cross-talk between AD and diabetes.
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Affiliation(s)
- Amany Mohamed
- Department of Pharmacology and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Anissa Viveiros
- Department of Pharmacology and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Kathleen Williams
- Department of Pharmacology and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Elena Posse de Chaves
- Department of Pharmacology and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
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38
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Gongol B, Marin TL, Jeppson JD, Mayagoitia K, Shin S, Sanchez N, Kirsch WM, Vinters HV, Wilson CG, Ghribi O, Soriano S. Cellular hormetic response to 27-hydroxycholesterol promotes neuroprotection through AICD induction of MAST4 abundance and kinase activity. Sci Rep 2017; 7:13898. [PMID: 29066835 PMCID: PMC5654999 DOI: 10.1038/s41598-017-13933-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 10/03/2017] [Indexed: 01/10/2023] Open
Abstract
The function of the amyloid precursor protein (APP) in brain health remains unclear. This study elucidated a novel cytoprotective signaling pathway initiated by the APP transcriptionally active intracellular domain (AICD) in response to 27-hydroxycholesterol (27OHC), an oxidized cholesterol metabolite associated with neurodegeneration. The cellular response to 27OHC was hormetic, such that low, but not high, doses promoted AICD transactivation of microtubule associated serine/threonine kinase family member 4 (MAST4). MAST4 in turn phosphorylated and inhibited FOXO1-dependent transcriptional repression of rhotekin 2 (RTKN2), an oxysterol stress responder, to optimize cell survival. A palmitate-rich diet, which increases serum 27OHC, or APP ablation, abrogated this response in vivo. Further, this pathway was downregulated in human Alzheimer's Disease (AD) brains but not in frontotemporal dementia brains. These results unveil MAST4 as functional kinase of FOXO1 in a 27OHC AICD-driven, hormetic pathway providing insight for therapeutic approaches against cholesterol associated neuronal disorders.
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Affiliation(s)
- Brendan Gongol
- Department of Pathology and Human Anatomy, Division of Anatomy, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA
- Cardiopulmonary Sciences, Schools of Allied Health Professions and Medicine, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Traci L Marin
- Cardiopulmonary Sciences, Schools of Allied Health Professions and Medicine, Loma Linda University, Loma Linda, CA, 92350, USA
| | - John D Jeppson
- Department of Pathology and Human Anatomy, Division of Anatomy, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA
| | - Karina Mayagoitia
- Department of Pathology and Human Anatomy, Division of Anatomy, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA
| | - Samuel Shin
- Department of Pathology and Human Anatomy, Division of Anatomy, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA
| | - Nicholas Sanchez
- Department of Basic Sciences, Division of Biochemistry, School of Medicine, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Wolff M Kirsch
- Department of Basic Sciences, Division of Biochemistry, School of Medicine, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Harry V Vinters
- Section of Neuropathology, Ronald Reagan UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, 90095, USA
| | - Christopher G Wilson
- Department of Basic Sciences, Division of Physiology, School of Medicine, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Othman Ghribi
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, 58202, USA
| | - Salvador Soriano
- Department of Pathology and Human Anatomy, Division of Anatomy, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA.
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Szalkai B, Grolmusz VK, Grolmusz VI. Identifying combinatorial biomarkers by association rule mining in the CAMD Alzheimer's database. Arch Gerontol Geriatr 2017; 73:300-307. [PMID: 28918286 DOI: 10.1016/j.archger.2017.08.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 08/09/2017] [Accepted: 08/12/2017] [Indexed: 11/29/2022]
Abstract
The concept of combinatorial biomarkers was conceived when it was noticed that simple biomarkers are often inadequate for recognizing and characterizing complex diseases. Here we present an algorithmic search method for complex biomarkers which may predict or indicate Alzheimer's disease (AD) and other kinds of dementia. We show that our method is universal since it can describe any Boolean function for biomarker discovery. We applied data mining techniques that are capable to uncover implication-like logical schemes with detailed quality scoring. The new SCARF program was applied for the Tucson, Arizona based Critical Path Institute's CAMD database, containing laboratory and cognitive test data for 5821 patients from the placebo arm of clinical trials of large pharmaceutical companies, and consequently, the data is much more reliable than numerous other databases for dementia. The results of our study on this larger than 5800-patient cohort suggest beneficial effects of high B12 vitamin level, negative effects of high sodium levels or high AST (aspartate aminotransferase) liver enzyme levels to cognition. As an example for a more complex and quite surprising rule: Low or normal blood glucose level with either low cholesterol or high serum sodium would also increase the probability of bad cognition with a 3.7 multiplier. The source code of the new SCARF program is publicly available at http://pitgroup.org/static/scarf.zip.
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Affiliation(s)
- Balázs Szalkai
- PIT Bioinformatics Group, Eötvös University, H-1117 Budapest, Hungary.
| | - Vince K Grolmusz
- 2nd Department of Internal Medicine, Semmelweis University, Budapest, Hungary..
| | - Vince I Grolmusz
- PIT Bioinformatics Group, Eötvös University, H-1117 Budapest, Hungary; Uratim Ltd., H-1118 Budapest, Hungary.
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40
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Mast N, Saadane A, Valencia-Olvera A, Constans J, Maxfield E, Arakawa H, Li Y, Landreth G, Pikuleva IA. Cholesterol-metabolizing enzyme cytochrome P450 46A1 as a pharmacologic target for Alzheimer's disease. Neuropharmacology 2017; 123:465-476. [PMID: 28655608 DOI: 10.1016/j.neuropharm.2017.06.026] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 06/21/2017] [Accepted: 06/23/2017] [Indexed: 12/27/2022]
Abstract
Cytochrome P450 46A1 (CYP46A1 or cholesterol 24-hydroxylase) controls cholesterol elimination from the brain and plays a role in higher order brain functions. Genetically enhanced CYP46A1 expression in mouse models of Alzheimer's disease mitigates the manifestations of this disease. We enhanced CYP46A1 activity pharmacologically by treating 5XFAD mice, a model of rapid amyloidogenesis, with a low dose of the anti-HIV medication efavirenz. Efavirenz was administered from 1 to 9 months of age, and mice were evaluated at specific time points. At one month of age, cholesterol homeostasis was already disturbed in the brain of 5XFAD mice. Nevertheless, efavirenz activated CYP46A1 and mouse cerebral cholesterol turnover during the first four months of administration. This treatment time also reduced amyloid burden and microglia activation in the cortex and subiculum of 5XFAD mice as well as protein levels of amyloid precursor protein and the expression of several genes involved in inflammatory response. However, mouse short-term memory and long-term spatial memory were impaired, whereas learning in the context-dependent fear test was improved. Additional four months of drug administration (a total of eight months of treatment) improved long-term spatial memory in the treated as compared to the untreated mice, further decreased amyloid-β content in 5XFAD brain, and also decreased the mortality rate among male mice. We propose a mechanistic model unifying the observed efavirenz effects. We suggest that CYP46A1 activation by efavirenz could be a new anti-Alzheimer's disease treatment and a tool to study and identify normal and pathological brain processes affected by cholesterol maintenance.
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Affiliation(s)
- Natalia Mast
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Aicha Saadane
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Ana Valencia-Olvera
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - James Constans
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Erin Maxfield
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Hiroyuki Arakawa
- Behavioral Core, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Young Li
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Gary Landreth
- Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Irina A Pikuleva
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA.
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41
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Suárez-Vega A, Toral PG, Gutiérrez-Gil B, Hervás G, Arranz JJ, Frutos P. Elucidating fish oil-induced milk fat depression in dairy sheep: Milk somatic cell transcriptome analysis. Sci Rep 2017; 7:45905. [PMID: 28378756 PMCID: PMC5381099 DOI: 10.1038/srep45905] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 03/06/2017] [Indexed: 12/20/2022] Open
Abstract
In this study, RNA sequencing was used to obtain a comprehensive profile of the transcriptomic changes occurring in the mammary gland of lactating sheep suffering from fish oil-induced milk fat depression (FO-MFD). The milk somatic cell transcriptome analysis of four control and four FO-MFD ewes generated an average of 42 million paired-end reads per sample. In both conditions, less than 220 genes constitute approximately 89% of the total counts. These genes, which are considered as core genes, were mainly involved in cytoplasmic ribosomal proteins and electron transport chain pathways. In total, 117 genes were upregulated, and 96 genes were downregulated in FO-MFD samples. Functional analysis of the latter indicated a downregulation of genes involved in the SREBP signaling pathway (e.g., ACACA, ACSL, and ACSS) and Gene Ontology terms related to lipid metabolism and lipid biosynthetic processes. Integrated interpretation of upregulated genes indicated enrichment in genes encoding plasma membrane proteins and proteins regulating protein kinase activity. Overall, our results indicate that FO-MFD is associated with the downregulation of key genes involved in the mammary lipogenesis process. In addition, the results also suggest that this syndrome may be related to upregulation of other genes implicated in signal transduction and codification of transcription factors.
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Affiliation(s)
- Aroa Suárez-Vega
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, León 24071, Spain
| | - Pablo G. Toral
- Instituto de Ganadería de Montaña (CSIC-ULE), Finca Marzanas s/n, Grulleros 24346, León, Spain
| | - Beatriz Gutiérrez-Gil
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, León 24071, Spain
| | - Gonzalo Hervás
- Instituto de Ganadería de Montaña (CSIC-ULE), Finca Marzanas s/n, Grulleros 24346, León, Spain
| | - Juan José Arranz
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, León 24071, Spain
| | - Pilar Frutos
- Instituto de Ganadería de Montaña (CSIC-ULE), Finca Marzanas s/n, Grulleros 24346, León, Spain
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42
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Doshina A, Gourgue F, Onizuka M, Opsomer R, Wang P, Ando K, Tasiaux B, Dewachter I, Kienlen-Campard P, Brion JP, Gailly P, Octave JN, Pierrot N. Cortical cells reveal APP as a new player in the regulation of GABAergic neurotransmission. Sci Rep 2017; 7:370. [PMID: 28337033 PMCID: PMC5428293 DOI: 10.1038/s41598-017-00325-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 02/21/2017] [Indexed: 12/30/2022] Open
Abstract
The amyloid precursor protein (APP) modulates synaptic activity, resulting from the fine tuning of excitatory and inhibitory neurotransmission. GABAergic inhibitory neurotransmission is affected by modifications in intracellular chloride concentrations regulated by Na+-K+-2Cl- cotransporter 1 (NKCC1) and neuronal K+-Cl- cotransporter 2 (KCC2), allowing entrance and efflux of chloride, respectively. Modifications in NKCC1 and KCC2 expression during maturation of cortical cells induce a shift in GABAergic signaling. Here, we demonstrated that APP affects this GABA shift. Expression of APP in cortical cells decreased the expression of KCC2, without modifying NKCC1, eliciting a less inhibitory GABA response. Downregulation of KCC2 expression by APP was independent of the APP intracellular domain, but correlated with decreased expression of upstream stimulating factor 1 (USF1), a potent regulator of Slc12a5 gene expression (encoding KCC2). KCC2 was also downregulated in vivo following APP expression in neonatal mouse brain. These results argue for a key role of APP in the regulation of GABAergic neurotransmission.
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Affiliation(s)
- Anna Doshina
- Institute of Neuroscience, Université catholique de Louvain, 1200, Brussels, Belgium
| | - Florian Gourgue
- Institute of Neuroscience, Université catholique de Louvain, 1200, Brussels, Belgium
| | - Michiho Onizuka
- Institute of Neuroscience, Université catholique de Louvain, 1200, Brussels, Belgium
| | - Remi Opsomer
- Institute of Neuroscience, Université catholique de Louvain, 1200, Brussels, Belgium
| | - Peng Wang
- Institute of Neuroscience, Université catholique de Louvain, 1200, Brussels, Belgium
| | - Kunie Ando
- Laboratory of Histology and Neuropathology, Université libre de Bruxelles, 1070, Brussels, Belgium
| | - Bernadette Tasiaux
- Institute of Neuroscience, Université catholique de Louvain, 1200, Brussels, Belgium
| | - Ilse Dewachter
- Institute of Neuroscience, Université catholique de Louvain, 1200, Brussels, Belgium
| | | | - Jean-Pierre Brion
- Laboratory of Histology and Neuropathology, Université libre de Bruxelles, 1070, Brussels, Belgium
| | - Philippe Gailly
- Institute of Neuroscience, Université catholique de Louvain, 1200, Brussels, Belgium
| | - Jean-Noël Octave
- Institute of Neuroscience, Université catholique de Louvain, 1200, Brussels, Belgium.
| | - Nathalie Pierrot
- Institute of Neuroscience, Université catholique de Louvain, 1200, Brussels, Belgium
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43
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Giampietro C, Lionetti MC, Costantini G, Mutti F, Zapperi S, La Porta CAM. Cholesterol impairment contributes to neuroserpin aggregation. Sci Rep 2017; 7:43669. [PMID: 28255164 PMCID: PMC5334643 DOI: 10.1038/srep43669] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 01/27/2017] [Indexed: 01/05/2023] Open
Abstract
Intraneural accumulation of misfolded proteins is a common feature of several neurodegenerative pathologies including Alzheimer's and Parkinson's diseases, and Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB). FENIB is a rare disease due to a point mutation in neuroserpin which accelerates protein aggregation in the endoplasmic reticulum (ER). Here we show that cholesterol depletion induced either by prolonged exposure to statins or by inhibiting the sterol reg-ulatory binding-element protein (SREBP) pathway also enhances aggregation of neuroserpin proteins. These findings can be explained considering a computational model of protein aggregation under non-equilibrium conditions, where a decrease in the rate of protein clearance improves aggregation. Decreasing cholesterol in cell membranes affects their biophysical properties, including their ability to form the vesicles needed for protein clearance, as we illustrate by a simple mathematical model. Taken together, these results suggest that cholesterol reduction induces neuroserpin aggregation, even in absence of specific neuroserpin mutations. The new mechanism we uncover could be relevant also for other neurodegenerative diseases associated with protein aggregation.
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Affiliation(s)
| | - Maria Chiara Lionetti
- Center for Complexity and Biosystems, Department of Biosciences, University of Milano, via Celoria 26, 20133 Milano, Italy
| | - Giulio Costantini
- Center for Complexity and Biosystems, Department of Physics, University of Milano, via Celoria 16, 20133 Milano, Italy
| | - Federico Mutti
- Center for Complexity and Biosystems, Department of Biosciences, University of Milano, via Celoria 26, 20133 Milano, Italy
| | - Stefano Zapperi
- Center for Complexity and Biosystems, Department of Physics, University of Milano, via Celoria 16, 20133 Milano, Italy
- CNR - Consiglio Nazionale delle Ricerche, Istituto di Chimica della Materia Condensata e di Tecnologie per l’Energia, Via R. Cozzi 53, 20125 Milano, Italy
- ISI Foundation, Via Alassio 11C, Torino, Italy
- Department of Applied Physics, Aalto University, P.O. Box 14100, FIN-00076, Aalto, Finland
| | - Caterina A. M. La Porta
- Center for Complexity and Biosystems, Department of Biosciences, University of Milano, via Celoria 26, 20133 Milano, Italy
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44
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May I Cut in? Gene Editing Approaches in Human Induced Pluripotent Stem Cells. Cells 2017; 6:cells6010005. [PMID: 28178187 PMCID: PMC5371870 DOI: 10.3390/cells6010005] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 01/20/2017] [Accepted: 01/30/2017] [Indexed: 12/16/2022] Open
Abstract
In the decade since Yamanaka and colleagues described methods to reprogram somatic cells into a pluripotent state, human induced pluripotent stem cells (hiPSCs) have demonstrated tremendous promise in numerous disease modeling, drug discovery, and regenerative medicine applications. More recently, the development and refinement of advanced gene transduction and editing technologies have further accelerated the potential of hiPSCs. In this review, we discuss the various gene editing technologies that are being implemented with hiPSCs. Specifically, we describe the emergence of technologies including zinc-finger nuclease (ZFN), transcription activator-like effector nuclease (TALEN), and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 that can be used to edit the genome at precise locations, and discuss the strengths and weaknesses of each of these technologies. In addition, we present the current applications of these technologies in elucidating the mechanisms of human development and disease, developing novel and effective therapeutic molecules, and engineering cell-based therapies. Finally, we discuss the emerging technological advances in targeted gene editing methods.
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45
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Petrov AM, Kasimov MR, Zefirov AL. Cholesterol in the Pathogenesis of Alzheimer's, Parkinson's Diseases and Autism: Link to Synaptic Dysfunction. Acta Naturae 2017; 9:26-37. [PMID: 28461971 PMCID: PMC5406657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Indexed: 11/30/2022] Open
Abstract
In our previous review, we described brain cholesterol metabolism in control conditions and in the case of some rare neurological pathologies linked to defects in the genes which are directly involved in the synthesis and/or traffic of cholesterol. Here, we have analyzed disruptions in cholesterol homeostasis in widespread neurodegenerative diseases (Alzheimer's and Parkinson's diseases) and autism spectrum disorders. We particularly focused on the synaptic dysfunctions that could arise from changes in both membrane cholesterol availability and oxysterol production. Notably, alterations in the brain cholesterol metabolism and neurotransmission occur in the early stages of these pathologies and the polymorphism of the genes associated with cholesterol homeostasis and synaptic communication affects the risk of onset and severity of these diseases. In addition, pharmacological and genetic manipulations of brain cholesterol homeostasis in animal models frequently have marked effects on the progression of neurodegenerative diseases. Thus, the development of Alzheimer's, Parkinson's and autism spectrum disorders may be partially associated with an imbalance of cholesterol homeostasis that leads to changes in the membrane cholesterol and oxysterol levels that, in turn, modulates key steps in the synaptic transmission.
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Affiliation(s)
- A. M. Petrov
- Kazan State Medical University, Normal Physiology department, Butlerova str. 49, Kazan, 420012, Russia
| | - M. R. Kasimov
- Kazan State Medical University, Normal Physiology department, Butlerova str. 49, Kazan, 420012, Russia
| | - A. L. Zefirov
- Kazan State Medical University, Normal Physiology department, Butlerova str. 49, Kazan, 420012, Russia
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46
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Woodruff G, Reyna SM, Dunlap M, Van Der Kant R, Callender JA, Young JE, Roberts EA, Goldstein LSB. Defective Transcytosis of APP and Lipoproteins in Human iPSC-Derived Neurons with Familial Alzheimer's Disease Mutations. Cell Rep 2016; 17:759-773. [PMID: 27732852 PMCID: PMC5796664 DOI: 10.1016/j.celrep.2016.09.034] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 07/22/2016] [Accepted: 09/12/2016] [Indexed: 12/16/2022] Open
Abstract
We investigated early phenotypes caused by familial Alzheimer's disease (fAD) mutations in isogenic human iPSC-derived neurons. Analysis of neurons carrying fAD PS1 or APP mutations introduced using genome editing technology at the endogenous loci revealed that fAD mutant neurons had previously unreported defects in the recycling state of endocytosis and soma-to-axon transcytosis of APP and lipoproteins. The endocytosis reduction could be rescued through treatment with a β-secretase inhibitor. Our data suggest that accumulation of β-CTFs of APP, but not Aβ, slow vesicle formation from an endocytic recycling compartment marked by the transcytotic GTPase Rab11. We confirm previous results that endocytosis is affected in AD and extend these to uncover a neuron-specific defect. Decreased lipoprotein endocytosis and transcytosis to the axon suggest that a neuron-specific impairment in endocytic axonal delivery of lipoproteins and other key materials might compromise synaptic maintenance in fAD.
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Affiliation(s)
- Grace Woodruff
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Sol M Reyna
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mariah Dunlap
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Rik Van Der Kant
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Julia A Callender
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jessica E Young
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Elizabeth A Roberts
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Lawrence S B Goldstein
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
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47
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Pierrot N, Lhommel R, Quenon L, Hanseeuw B, Dricot L, Sindic C, Maloteaux JM, Octavea JN, Ivanoiu A. Targretin Improves Cognitive and Biological Markers in a Patient with Alzheimer's Disease. J Alzheimers Dis 2016; 49:271-6. [PMID: 26444777 DOI: 10.3233/jad-150405] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We present the effects of Targretin® (bexarotene) on cognition and biomarkers in a patient with mild Alzheimer's disease (AD). Targretin® is a Retinoic X Receptor (RXR) agonist shown to improve synaptic and cognitive functions in animal models of AD by increasing neuronal cholesterol efflux. After 6 months of treatment with Targretin® 300 mg/day, memory improved by about 40% and the tau protein in the cerebrospinal fluid decreased by about 20% . No significant side effects were noticed. This observation in a single patient indicates that Targretin® may improve memory performance and biological markers at an early stage of AD.
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Affiliation(s)
- Nathalie Pierrot
- Université catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium
| | - Renaud Lhommel
- Université catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium.,Cliniques universitaires Saint Luc, Nuclear Medicine department, Brussels, Belgium
| | - Lisa Quenon
- Université catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium
| | - Bernard Hanseeuw
- Université catholique de Louvain, Brussels, Belgium.,Cliniques universitaires Saint Luc, Neurology department, Brussels, Belgium
| | - Laurence Dricot
- Université catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium
| | - Christian Sindic
- Université catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium
| | - Jean-Marie Maloteaux
- Université catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium.,Cliniques universitaires Saint Luc, Neurology department, Brussels, Belgium
| | - Jean-Noël Octavea
- Université catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium
| | - Adrian Ivanoiu
- Université catholique de Louvain, Brussels, Belgium.,Institute of Neuroscience, Brussels, Belgium.,Cliniques universitaires Saint Luc, Neurology department, Brussels, Belgium
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48
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Paschkowsky S, Hamzé M, Oestereich F, Munter LM. Alternative Processing of the Amyloid Precursor Protein Family by Rhomboid Protease RHBDL4. J Biol Chem 2016; 291:21903-21912. [PMID: 27563067 DOI: 10.1074/jbc.m116.753582] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Indexed: 12/13/2022] Open
Abstract
The amyloid precursor protein (APP) is an ubiquitously expressed cell surface protein and a key molecule in the etiology of Alzheimer disease. Amyloidogenic processing of APP through secretases leads to the generation of toxic amyloid β (Aβ) peptides, which are regarded as the molecular cause of the disease. We report here an alternative processing pathway of APP through the mammalian intramembrane rhomboid protease RHBDL4. RHBDL4 efficiently cleaves APP inside the cell, thus bypassing APP from amyloidogenic processing, leading to reduced Aβ levels. RHBDL4 cleaves APP multiple times in the ectodomain, resulting in several N- and C-terminal fragments that are not further degraded by classical APP secretases. Knockdown of endogenous RHBDL4 results in decreased levels of C-terminal fragments derived from endogenous APP. Similarly, we found the APP family members APLP1 and APLP2 to be substrates of RHBDL4. We conclude that RHBDL4-mediated APP processing provides insight into APP and rhomboid physiology and qualifies for further investigations to elaborate its impact on Alzheimer disease pathology.
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Affiliation(s)
| | - Mehdi Hamzé
- From the Department of Pharmacology and Therapeutics and
| | - Felix Oestereich
- From the Department of Pharmacology and Therapeutics and Integrated Program in Neuroscience, McGill University, Montreal, Quebec H3G 0B1, Canada
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49
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Dietary composition affects the development of cognitive deficits in WT and Tg AD model mice. Exp Gerontol 2016; 86:39-49. [PMID: 27167583 DOI: 10.1016/j.exger.2016.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 04/22/2016] [Accepted: 05/06/2016] [Indexed: 01/17/2023]
Abstract
Clinical and epidemiological evidence suggests that lifestyle factors, including nutrition, may influence the chances of developing of Alzheimer's disease (AD), and also likely affect the aging process. Whereas it is clear that high-fat diets are increasing both body weight and the risk of developing Alzheimer's disease, to date, there have been very few studies comparing diets high with different sources of calories (i.e., high fat versus high protein versus high carbohydrates) to determine whether dietary composition has importance beyond the known effect of high caloric intake to increase body weight, AD pathology and cognitive deficits. In the current study we examined the effects that different diets high in carbohydrate, protein or fat content, but similar in caloric value, have on the development of cognitive impairment and brain pathology in wild-type and Tg AD model mice. The results demonstrate that long term feeding with balanced diets similar in caloric content but with significant changes in the source of calories, all negatively influence cognition compared to the control diet, and that this effect is more pronounced in Tg animals with AD pathology.
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50
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Su TP, Su TC, Nakamura Y, Tsai SY. The Sigma-1 Receptor as a Pluripotent Modulator in Living Systems. Trends Pharmacol Sci 2016; 37:262-278. [PMID: 26869505 PMCID: PMC4811735 DOI: 10.1016/j.tips.2016.01.003] [Citation(s) in RCA: 222] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Revised: 01/03/2016] [Accepted: 01/05/2016] [Indexed: 01/21/2023]
Abstract
The sigma-1 receptor (Sig-1R) is an endoplasmic reticulum (ER) protein that resides specifically in the mitochondria-associated endoplasmic reticulum (ER) membrane (MAM), an interface between ER and mitochondria. In addition to being able to translocate to the plasma membrane (PM) to interact with ion channels and other receptors, Sig-1R also occurs at the nuclear envelope, where it recruits chromatin-remodeling factors to affect the transcription of genes. Sig-1Rs have also been reported to interact with other membranous or soluble proteins at other loci, including the cytosol, and to be involved in several central nervous system (CNS) diseases. Here, we propose that Sig-1R is a pluripotent modulator with resultant multiple functional manifestations in living systems.
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Affiliation(s)
- Tsung-Ping Su
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD 21224, USA.
| | - Tzu-Chieh Su
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD 21224, USA
| | - Yoki Nakamura
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD 21224, USA
| | - Shang-Yi Tsai
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD 21224, USA
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