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Krogsaeter EK, McKetney J, Marquez A, Cakir Z, Stevenson E, Jang GM, Rao A, Zhou A, Huang Y, Krogan NJ, Swaney DL. Lysosomal proteomics reveals mechanisms of neuronal apoE4associated lysosomal dysfunction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.02.560519. [PMID: 37873080 PMCID: PMC10592882 DOI: 10.1101/2023.10.02.560519] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
ApoE4 is the primary risk factor for Alzheimer's Disease. While apoE is primarily expressed by astrocytes, AD pathology including endosomal abnormalities and mitochondrial dysfunction first occurs in neurons. Lysosomes are poised at the convergence point between these features. We find that apoE4-expressing cells exhibit lysosomal alkalinization, reduced lysosomal proteolysis, and impaired mitophagy. To identify driving factors for this lysosomal dysfunction, we performed quantitative lysosomal proteome profiling. This revealed that apoE4 expression results in lysosomal depletion of Lgals3bp and accumulation of Tmed5 in both Neuro-2a cells and postmitotic human neurons. Modulating the expression of both proteins affected lysosomal function, with Tmed5 knockdown rescuing lysosomal alkalinization in apoE4 cells, and Lgals3bp knockdown causing lysosomal alkalinization and reduced lysosomal density in apoE3 cells. Taken together, our work reveals that apoE4 exerts gain-of-toxicity by alkalinizing the lysosomal lumen, pinpointing lysosomal Tmed5 accumulation and Lgals3bp depletion as apoE4-associated drivers for this phenotype.
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Affiliation(s)
- Einar K. Krogsaeter
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
- These authors contributed equally
| | - Justin McKetney
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
- These authors contributed equally
| | - Angelica Marquez
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
| | - Zeynep Cakir
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
| | - Erica Stevenson
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
| | - Gwendolyn M. Jang
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
| | - Antara Rao
- Gladstone Institute of Neurological Disease, The J. David Gladstone Institutes, San Francisco, USA
- Developmental and Stem Cell Biology Graduate Program, University of California, San Francisco, USA
| | - Anton Zhou
- Gladstone Institute of Neurological Disease, The J. David Gladstone Institutes, San Francisco, USA
| | - Yadong Huang
- Gladstone Institute of Neurological Disease, The J. David Gladstone Institutes, San Francisco, USA
- Developmental and Stem Cell Biology Graduate Program, University of California, San Francisco, USA
- Neuroscience Graduate Program, University of California, San Francisco, USA
- Gladstone Center for Translational Advancement, Gladstone Institutes, San Francisco, USA
- Biomedical Sciences Graduate Program, University of California, San Francisco, USA
- Departments of Neurology and Pathology, University of California, San Francisco, USA
| | - Nevan J. Krogan
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
| | - Danielle L. Swaney
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
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2
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Bazzone A, Barthmes M, George C, Brinkwirth N, Zerlotti R, Prinz V, Cole K, Friis S, Dickson A, Rice S, Lim J, Fern Toh M, Mohammadi M, Pau D, Stone DJ, Renger JJ, Fertig N. A Comparative Study on the Lysosomal Cation Channel TMEM175 Using Automated Whole-Cell Patch-Clamp, Lysosomal Patch-Clamp, and Solid Supported Membrane-Based Electrophysiology: Functional Characterization and High-Throughput Screening Assay Development. Int J Mol Sci 2023; 24:12788. [PMID: 37628970 PMCID: PMC10454728 DOI: 10.3390/ijms241612788] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/09/2023] [Accepted: 08/12/2023] [Indexed: 08/27/2023] Open
Abstract
The lysosomal cation channel TMEM175 is a Parkinson's disease-related protein and a promising drug target. Unlike whole-cell automated patch-clamp (APC), lysosomal patch-clamp (LPC) facilitates physiological conditions, but is not yet suitable for high-throughput screening (HTS) applications. Here, we apply solid supported membrane-based electrophysiology (SSME), which enables both direct access to lysosomes and high-throughput electrophysiological recordings. In SSME, ion translocation mediated by TMEM175 is stimulated using a concentration gradient at a resting potential of 0 mV. The concentration-dependent K+ response exhibited an I/c curve with two distinct slopes, indicating the existence of two conducting states. We measured H+ fluxes with a permeability ratio of PH/PK = 48,500, which matches literature findings from patch-clamp studies, validating the SSME approach. Additionally, TMEM175 displayed a high pH dependence. Decreasing cytosolic pH inhibited both K+ and H+ conductivity of TMEM175. Conversely, lysosomal pH and pH gradients did not have major effects on TMEM175. Finally, we developed HTS assays for drug screening and evaluated tool compounds (4-AP, Zn as inhibitors; DCPIB, arachidonic acid, SC-79 as enhancers) using SSME and APC. Additionally, we recorded EC50 data for eight blinded TMEM175 enhancers and compared the results across all three assay technologies, including LPC, discussing their advantages and disadvantages.
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Affiliation(s)
- Andre Bazzone
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
| | - Maria Barthmes
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
| | - Cecilia George
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
| | - Nina Brinkwirth
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
| | - Rocco Zerlotti
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
- RIGeL-Regensburg International Graduate School of Life Sciences, University of Regensburg, 93053 Regensburg, Germany
| | - Valentin Prinz
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
| | - Kim Cole
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
| | - Søren Friis
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
| | - Alexander Dickson
- SB Drug Discovery, West of Scotland Science Park, Glasgow G20 0XA, UK; (A.D.); (S.R.)
| | - Simon Rice
- SB Drug Discovery, West of Scotland Science Park, Glasgow G20 0XA, UK; (A.D.); (S.R.)
| | - Jongwon Lim
- Cerevel Therapeutics, 222 Jacobs St, Cambridge, MA 02141, USA; (J.L.); (M.F.T.); (D.J.S.); (J.J.R.)
| | - May Fern Toh
- Cerevel Therapeutics, 222 Jacobs St, Cambridge, MA 02141, USA; (J.L.); (M.F.T.); (D.J.S.); (J.J.R.)
| | | | - Davide Pau
- SB Drug Discovery, West of Scotland Science Park, Glasgow G20 0XA, UK; (A.D.); (S.R.)
| | - David J. Stone
- Cerevel Therapeutics, 222 Jacobs St, Cambridge, MA 02141, USA; (J.L.); (M.F.T.); (D.J.S.); (J.J.R.)
| | - John J. Renger
- Cerevel Therapeutics, 222 Jacobs St, Cambridge, MA 02141, USA; (J.L.); (M.F.T.); (D.J.S.); (J.J.R.)
| | - Niels Fertig
- Nanion Technologies, Ganghoferstr. 70a, 80339 Munich, Germany (V.P.); (S.F.)
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3
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Rha AK, Maguire AS, Martin DR. GM1 Gangliosidosis: Mechanisms and Management. Appl Clin Genet 2021; 14:209-233. [PMID: 33859490 PMCID: PMC8044076 DOI: 10.2147/tacg.s206076] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 01/15/2021] [Indexed: 01/10/2023] Open
Abstract
The lysosomal storage disorder, GM1 gangliosidosis (GM1), is a neurodegenerative condition resulting from deficiency of the enzyme β-galactosidase (β-gal). Mutation of the GLB1 gene, which codes for β-gal, prevents cleavage of the terminal β-1,4-linked galactose residue from GM1 ganglioside. Subsequent accumulation of GM1 ganglioside and other substrates in the lysosome impairs cell physiology and precipitates dysfunction of the nervous system. Beyond palliative and supportive care, no FDA-approved treatments exist for GM1 patients. Researchers are critically evaluating the efficacy of substrate reduction therapy, pharmacological chaperones, enzyme replacement therapy, stem cell transplantation, and gene therapy for GM1. A Phase I/II clinical trial for GM1 children is ongoing to evaluate the safety and efficacy of adeno-associated virus-mediated GLB1 delivery by intravenous injection, providing patients and families with hope for the future.
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Affiliation(s)
- Allisandra K Rha
- Scott-Ritchey Research Center, Auburn University, Auburn, AL, 36849, USA
| | - Anne S Maguire
- Scott-Ritchey Research Center, Auburn University, Auburn, AL, 36849, USA
- Department of Anatomy, Physiology, and Pharmacology, Auburn University College of Veterinary Medicine, Auburn, AL, 36849, USA
| | - Douglas R Martin
- Scott-Ritchey Research Center, Auburn University, Auburn, AL, 36849, USA
- Department of Anatomy, Physiology, and Pharmacology, Auburn University College of Veterinary Medicine, Auburn, AL, 36849, USA
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4
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Chambraud B, Daguinot C, Guillemeau K, Genet M, Dounane O, Meduri G, Poüs C, Baulieu EE, Giustiniani J. Decrease of neuronal FKBP4/FKBP52 modulates perinuclear lysosomal positioning and MAPT/Tau behavior during MAPT/Tau-induced proteotoxic stress. Autophagy 2021; 17:3491-3510. [PMID: 33459145 DOI: 10.1080/15548627.2021.1875611] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Defects of autophagy-lysosomal protein degradation are thought to contribute to the pathogenesis of several neurodegenerative diseases, and the accumulation of aggregation prone proteins such as MAPT/Tau in Alzheimer disease (AD). We previously showed the localization of the immunophilin FKBP4/FKBP52 in the lysosomal system of healthy human neurons suggesting its possible role in lysosome function. We also showed that decreased FKBP4 levels in AD brain neurons correlate with abnormal MAPT accumulation and aggregation. In this study, we demonstrate that FKBP4 decrease in a human neuronal cell line (SH-SY5Y) and in dorsal root ganglion (DRG) neurons from human MAPTP301S transgenic mice affected the function of the autophagy-lysosomal system under MAPT induced proteotoxic stress conditions. We show that acute MAPT accumulation in SH-SY5Y cells induced perinuclear clustering of lysosomes, triggered FKBP4 localization around the clusters and its colocalization with MAPT and MAP1LC3/LC3-positive autophagic vesicles; a similar FKBP4 localization was detected in some AD brain neurons. We demonstrate that FKBP4 decrease altered lysosomal clustering along with MAPT and MAP1LC3 secretion increase. Although ectopic FKBP4 expression could not induce autophagy under our experimental conditions, it prevented MAPT secretion after MAPT accumulation in SH-SY5Y cells implying a regulatory role of FKBP4 on MAPT secretion. Finally, we observe that FKBP4 deficiency decreased MAP1LC3-II expression and provoked MAPT accumulation during long-term stress in mouse DRG neurons. We hypothesize that the abnormal FKBP4 decrease observed in AD brain neurons might hinder autophagy efficiency and contribute to the progression of the tauopathy by modulating MAPT secretion and accumulation during MAPT pathogenesis.Abbreviations: AD: Alzheimer disease; AKT/protein kinase B: AKT serine/threonine kinase; ALP: Autophagy-lysosomal pathway; ATG: autophagy-related; BafA1: bafilomycin A1; CQ: chloroquine; CTSD: cathepsin D; DIV: days in vitro; DRG: dorsal root ganglion neurons; Dox: doxycycline; DNAJC5: DnaJ heat shock protein family (Hsp40) member C5; EL: empty lentiviral vectors; ENO2/NSE: enolase 2, gamma neuronal; FKBP4/FKBP52: FKBP prolyl isomerase 4; FTLD-Tau: frontotemporal lobar degeneration with Tau pathology; GFP: green fluorescent protein; LAMP1: lysosomal associated membrane protein 1; LDH: lactate dehydrogenase; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MAPT/Tau: microtubule associated protein tau; MTT: tetrazolium salt; NFTs: neurofibrillary tangles; RPE-1: retinal pigment epithelial cells; shRNA: small-hairpin ribonucleic acid; SQSTM1/p62: sequestosome 1; SD: standard deviation; SEM: standard error of the mean; SH-SY5Y: human neuroblastoma cells; Sh1 or Sh2: Lentiviral shRNA vectors inducing FKBP4 decrease; SH-52GFP: MAPT/Tau-inducible SH-SY5Y cell line constitutively expressing FKBP4-GFP; TUBB3/βIII tubulin: tubulin beta 3 class III; UPS: ubiquitin-proteasome system.
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Affiliation(s)
| | | | | | - Melanie Genet
- INSERM U1195, Université Paris-Saclay, Kremlin-Bicêtre, France
| | - Omar Dounane
- INSERM U1195, Université Paris-Saclay, Kremlin-Bicêtre, France
| | - Geri Meduri
- INSERM U1195, Université Paris-Saclay, Kremlin-Bicêtre, France
| | - Christian Poüs
- INSERM UMR-S-1193, Université Paris-Saclay, Châtenay-Malabry, France.,Biochimie-Hormonologie , AP-HP Université Paris-Saclay, Site Antoine Béclère, Clamart, France
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5
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Chen X, Zhang T, Zhang Y. Endoplasmic reticulum stress and autophagy in HIV-1-associated neurocognitive disorders. J Neurovirol 2020; 26:824-833. [PMID: 32918163 DOI: 10.1007/s13365-020-00906-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/24/2020] [Accepted: 08/28/2020] [Indexed: 12/11/2022]
Abstract
Although antiretroviral therapy (ART) affects virologic suppression and prolongs life expectancies among HIV-positive patients; HIV-1-associated neurocognitive disorders (HAND) continue to be diagnosed in patients with HIV-1 undergoing treatment. The extensive clinical manifestations of HAND include behavioral, cognitive, and motor dysfunctions that severely affect the patients' quality of life. The pathogenesis of HAND has received increasing attention as a potential avenue by which to improve the treatment of the condition. Many studies have shown that endoplasmic reticulum (ER) stress, autophagy, and their interaction play important roles in the onset and development of neurodegenerative diseases. While the accumulation of misfolded proteins can induce ER stress, autophagy can effectively remove accumulated toxic proteins, reduce ER stress, and thus inhibit the development of neuropathy. Through the in-depth study of ER stress and autophagy, both have been recognized as promising targets for pharmacotherapeutic intervention in the treatment of HAND. This review will highlight the effects of ER stress, autophagy, and their interaction in the context of HAND, thereby helping to inform the future development of targeted treatments for patients with HAND.
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Affiliation(s)
- Xue Chen
- Department of Infectious Diseases, Beijing You An Hospital, Beijing Institute of Hepatology, Capital Medical University, Beijing, 100069, China
| | - Tong Zhang
- Department of Infectious Diseases, Beijing You An Hospital, Beijing Institute of Hepatology, Capital Medical University, Beijing, 100069, China.
| | - Yulin Zhang
- Department of Infectious Diseases, Beijing You An Hospital, Beijing Institute of Hepatology, Capital Medical University, Beijing, 100069, China.
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6
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Hansen L, Husein DM, Gericke B, Hansen T, Pedersen O, Tambe MA, Freeze HH, Naim HY, Henrissat B, Wandall HH, Clausen H, Bennett EP. A mutation map for human glycoside hydrolase genes. Glycobiology 2020; 30:500-515. [PMID: 32039448 PMCID: PMC7372926 DOI: 10.1093/glycob/cwaa010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 01/31/2020] [Accepted: 02/04/2020] [Indexed: 12/11/2022] Open
Abstract
Glycoside hydrolases (GHs) are found in all domains of life, and at least 87 distinct genes encoding proteins related to GHs are found in the human genome. GHs serve diverse functions from digestion of dietary polysaccharides to breakdown of intracellular oligosaccharides, glycoproteins, proteoglycans and glycolipids. Congenital disorders of GHs (CDGHs) represent more than 30 rare diseases caused by mutations in one of the GH genes. We previously used whole-exome sequencing of a homogenous Danish population of almost 2000 individuals to probe the incidence of deleterious mutations in the human glycosyltransferases (GTs) and developed a mutation map of human GT genes (GlyMAP-I). While deleterious disease-causing mutations in the GT genes were very rare, and in many cases lethal, we predicted deleterious mutations in GH genes to be less rare and less severe given the higher incidence of CDGHs reported worldwide. To probe the incidence of GH mutations, we constructed a mutation map of human GH-related genes (GlyMAP-II) using the Danish WES data, and correlating this with reported disease-causing mutations confirmed the higher prevalence of disease-causing mutations in several GH genes compared to GT genes. We identified 76 novel nonsynonymous single-nucleotide variations (nsSNVs) in 32 GH genes that have not been associated with a CDGH phenotype, and we experimentally validated two novel potentially damaging nsSNVs in the congenital sucrase-isomaltase deficiency gene, SI. Our study provides a global view of human GH genes and disease-causing mutations and serves as a discovery tool for novel damaging nsSNVs in CDGHs.
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Affiliation(s)
- Lars Hansen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Mærsk Building, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Diab M Husein
- Department of Physiological Chemistry, University of Veterinary Medicine Hannover, Bünteweg 2, 30559 Hannover, Germany
| | - Birthe Gericke
- Department of Physiological Chemistry, University of Veterinary Medicine Hannover, Bünteweg 2, 30559 Hannover, Germany
| | - Torben Hansen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Mærsk Building, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Oluf Pedersen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Mærsk Building, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Mitali A Tambe
- Human Genetics Program, Sanford-Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Hudson H Freeze
- Human Genetics Program, Sanford-Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Hassan Y Naim
- Department of Physiological Chemistry, University of Veterinary Medicine Hannover, Bünteweg 2, 30559 Hannover, Germany
| | - Bernard Henrissat
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Mærsk Building, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
- Architecture et Fonction des Macromolécules Biologiques, Centre National de la Recherche Scientifique (CNRS) and Aix-Marseille University Marseille, 163 Avenue de Luminy, 13288 Marseille CEDEX 09, France
| | - Hans H Wandall
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Mærsk Building, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Henrik Clausen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Mærsk Building, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Eric P Bennett
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Mærsk Building, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
- School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Nørre Allé 20, DK-2200 Copenhagen N, Denmark
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7
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Kraut RS, Knust E. Changes in endolysosomal organization define a pre-degenerative state in the crumbs mutant Drosophila retina. PLoS One 2019; 14:e0220220. [PMID: 31834921 PMCID: PMC6910688 DOI: 10.1371/journal.pone.0220220] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 11/24/2019] [Indexed: 01/06/2023] Open
Abstract
Mutations in the epithelial polarity gene crumbs (crb) lead to retinal degeneration in Drosophila and in humans. The overall morphology of the retina and its deterioration in Drosophila crb mutants has been well-characterized, but the cell biological origin of the degeneration is not well understood. Degenerative conditions in the retina and elsewhere in the nervous system often involve defects in degradative intracellular trafficking pathways. So far, however, effects of crb on the endolysosomal system, or on the spatial organization of these compartments in photoreceptor cells have not been described. We therefore asked whether photoreceptors in crb mutants exhibit alterations in endolysosomal compartments under pre-degenerative conditions, where the retina is still morphologically intact. Data presented here show that, already well before the onset of degeneration, Arl8, Rab7, and Atg8-carrying endolysosomal and autophagosomal compartments undergo changes in morphology and positioning with respect to each other in crb mutant retinas. We propose that these changes may be early signs of the degeneration-prone condition in crb retinas.
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Affiliation(s)
- Rachel S. Kraut
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse, Dresden, Germany
- * E-mail:
| | - Elisabeth Knust
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse, Dresden, Germany
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8
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Gallardo G, Wong CH, Ricardez SM, Mann CN, Lin KH, Leyns CEG, Jiang H, Holtzman DM. Targeting tauopathy with engineered tau-degrading intrabodies. Mol Neurodegener 2019; 14:38. [PMID: 31640765 PMCID: PMC6805661 DOI: 10.1186/s13024-019-0340-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 10/09/2019] [Indexed: 12/21/2022] Open
Abstract
Background The accumulation of pathological tau is the main component of neurofibrillary tangles and other tau aggregates in several neurodegenerative diseases, referred to as tauopathies. Recently, immunotherapeutic approaches targeting tau have been demonstrated to be beneficial in decreasing tauopathy in animal models. We previously found that passive immunotherapy with anti-tau antibody to human tau or expression of an anti-tau secreted single-chain variable fragment (scFv) in the central nervous system of a mouse model of tauopathy decreased but did not remove all tau-associated pathology. Although these and other studies demonstrate that conventional immunotherapeutic approaches targeting tau can influence tau pathogenesis, the majority of pathological tau remains in the cytosol of cells, not typically accessible to an extracellular antibody. Therefore, we reasoned targeting intracellular tau might be more efficacious in preventing or decreasing tauopathy. Methods By utilizing our anti-tau scFv, we generated anti-tau intrabodies for the expression in the cytosol of neurons. To enhance the degradation capacity of conventional intrabodies, we engineered chimeric anti-tau intrabodies fused to ubiquitin harboring distinct mutations that shuttle intracellular tau for either the proteasome or lysosomal mediated degradation. To evaluate the efficacy in delaying or eliminating tauopathy, we expressed our tau degrading intrabodies or controls in human tau transgenic mice by adeno-associated virus prior to overt tau pathology and after tau deposition. Results Our results demonstrate, the expression of chimeric anti-tau intrabodies significantly reduce tau protein levels in primary neuronal cultures expression human tau relative to a non-modified anti-tau intrabody. We found the expression of engineered tau-degrading intrabodies destined for proteasomal-mediated degradation are more effective in delaying or eliminating tauopathy than a conventional intrabody in aged human tau transgenic mice. Conclusion This study, harnesses the strength of intrabodies that are amendable for targeting specific domains or modifications with the cell-intrinsic mechanisms that regulate protein degradation providing a new immunotherapeutic approach with potentially improved efficacy.
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Affiliation(s)
- Gilbert Gallardo
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, 63110, USA. .,Hope Center for Neurological Disorders, Washington University, Campus Box 8111, 660 S. Euclid Avenue, St. Louis, MO, 63110, USA.
| | - Connie H Wong
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Hope Center for Neurological Disorders, Washington University, Campus Box 8111, 660 S. Euclid Avenue, St. Louis, MO, 63110, USA.,Department of Molecular Genetics and Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Sara M Ricardez
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Hope Center for Neurological Disorders, Washington University, Campus Box 8111, 660 S. Euclid Avenue, St. Louis, MO, 63110, USA
| | - Carolyn N Mann
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Hope Center for Neurological Disorders, Washington University, Campus Box 8111, 660 S. Euclid Avenue, St. Louis, MO, 63110, USA
| | - Kent H Lin
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Hope Center for Neurological Disorders, Washington University, Campus Box 8111, 660 S. Euclid Avenue, St. Louis, MO, 63110, USA
| | - Cheryl E G Leyns
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Hope Center for Neurological Disorders, Washington University, Campus Box 8111, 660 S. Euclid Avenue, St. Louis, MO, 63110, USA.,Charles F. and Joanne Knight Alzheimer's Disease Research Center, Washington University, St. Louis, MO, USA.,Neuroscience Discovery, Merck Research Laboratories, Boston, MA, 02115, USA
| | - Hong Jiang
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Hope Center for Neurological Disorders, Washington University, Campus Box 8111, 660 S. Euclid Avenue, St. Louis, MO, 63110, USA.,Charles F. and Joanne Knight Alzheimer's Disease Research Center, Washington University, St. Louis, MO, USA
| | - David M Holtzman
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, 63110, USA. .,Hope Center for Neurological Disorders, Washington University, Campus Box 8111, 660 S. Euclid Avenue, St. Louis, MO, 63110, USA. .,Charles F. and Joanne Knight Alzheimer's Disease Research Center, Washington University, St. Louis, MO, USA.
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9
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Hwang J, Estick CM, Ikonne US, Butler D, Pait MC, Elliott LH, Ruiz S, Smith K, Rentschler KM, Mundell C, Almeida MF, Stumbling Bear N, Locklear JP, Abumohsen Y, Ivey CM, Farizatto KLG, Bahr BA. The Role of Lysosomes in a Broad Disease-Modifying Approach Evaluated across Transgenic Mouse Models of Alzheimer's Disease and Parkinson's Disease and Models of Mild Cognitive Impairment. Int J Mol Sci 2019; 20:E4432. [PMID: 31505809 PMCID: PMC6770842 DOI: 10.3390/ijms20184432] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/03/2019] [Accepted: 09/05/2019] [Indexed: 12/17/2022] Open
Abstract
Many neurodegenerative disorders have lysosomal impediments, and the list of proposed treatments targeting lysosomes is growing. We investigated the role of lysosomes in Alzheimer's disease (AD) and other age-related disorders, as well as in a strategy to compensate for lysosomal disturbances. Comprehensive immunostaining was used to analyze brains from wild-type mice vs. amyloid precursor protein/presenilin-1 (APP/PS1) mice that express mutant proteins linked to familial AD. Also, lysosomal modulation was evaluated for inducing synaptic and behavioral improvements in transgenic models of AD and Parkinson's disease, and in models of mild cognitive impairment (MCI). Amyloid plaques were surrounded by swollen organelles positive for the lysosome-associated membrane protein 1 (LAMP1) in the APP/PS1 cortex and hippocampus, regions with robust synaptic deterioration. Within neurons, lysosomes contain the amyloid β 42 (Aβ42) degradation product Aβ38, and this indicator of Aβ42 detoxification was augmented by Z-Phe-Ala-diazomethylketone (PADK; also known as ZFAD) as it enhanced the lysosomal hydrolase cathepsin B (CatB). PADK promoted Aβ42 colocalization with CatB in lysosomes that formed clusters in neurons, while reducing Aβ deposits as well. PADK also reduced amyloidogenic peptides and α-synuclein in correspondence with restored synaptic markers, and both synaptic and cognitive measures were improved in the APP/PS1 and MCI models. These findings indicate that lysosomal perturbation contributes to synaptic and cognitive decay, whereas safely enhancing protein clearance through modulated CatB ameliorates the compromised synapses and cognition, thus supporting early CatB upregulation as a disease-modifying therapy that may also slow the MCI to dementia continuum.
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Affiliation(s)
- Jeannie Hwang
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
- Department of Pharmaceutical Sciences and the Neurosciences Program, University of Connecticut, Storrs, CT 06269, USA
| | - Candice M Estick
- Department of Pharmaceutical Sciences and the Neurosciences Program, University of Connecticut, Storrs, CT 06269, USA
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT 06269, USA
| | - Uzoma S Ikonne
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
| | - David Butler
- Department of Pharmaceutical Sciences and the Neurosciences Program, University of Connecticut, Storrs, CT 06269, USA
- Center for Drug Discovery, Northeastern University, Boston, MA 02115, USA
| | - Morgan C Pait
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
- Department of Chemistry and Physics, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
| | - Lyndsie H Elliott
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
- Department of Biology, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
| | - Sarah Ruiz
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
- Department of Biology, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
| | - Kaitlan Smith
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
- Molecular Biotechnology Program University of North Carolina-Pembroke, Pembroke, NC 28372, USA
| | - Katherine M Rentschler
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
| | - Cary Mundell
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
- Department of Biology, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
| | - Michael F Almeida
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
| | - Nicole Stumbling Bear
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
- Department of Biology, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
| | - James P Locklear
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
- Department of Biology, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
| | - Yara Abumohsen
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
- Department of Biology, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
| | - Cecily M Ivey
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
- Department of Biology, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
| | - Karen L G Farizatto
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
- Department of Biology, University of North Carolina-Pembroke, Pembroke, NC 28372, USA
| | - Ben A Bahr
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina-Pembroke, Pembroke, NC 28372, USA.
- Department of Pharmaceutical Sciences and the Neurosciences Program, University of Connecticut, Storrs, CT 06269, USA.
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT 06269, USA.
- Department of Chemistry and Physics, University of North Carolina-Pembroke, Pembroke, NC 28372, USA.
- Department of Biology, University of North Carolina-Pembroke, Pembroke, NC 28372, USA.
- Molecular Biotechnology Program University of North Carolina-Pembroke, Pembroke, NC 28372, USA.
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10
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Delos Santos K, Kim M, Yergeau C, Jean S, Moon NS. Pleiotropic role of Drosophila phosphoribosyl pyrophosphate synthetase in autophagy and lysosome homeostasis. PLoS Genet 2019; 15:e1008376. [PMID: 31487280 PMCID: PMC6748441 DOI: 10.1371/journal.pgen.1008376] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 09/17/2019] [Accepted: 08/17/2019] [Indexed: 01/07/2023] Open
Abstract
Phosphoribosyl pyrophosphate synthetase (PRPS) is a rate-limiting enzyme whose function is important for the biosynthesis of purines, pyrimidines, and pyridines. Importantly, while missense mutations of PRPS1 have been identified in neurological disorders such as Arts syndrome, how they contribute to neuropathogenesis is still unclear. We identified the Drosophila ortholog of PRPS (dPRPS) as a direct target of RB/E2F in Drosophila, a vital cell cycle regulator, and engineered dPRPS alleles carrying patient-derived mutations. Interestingly, while they are able to develop normally, dPRPS mutant flies have a shortened lifespan and locomotive defects, common phenotypes associated with neurodegeneration. Careful analysis of the fat body revealed that patient-derived PRPS mutations result in profound defects in lipolysis, macroautophagy, and lysosome function. Significantly, we show evidence that the nervous system of dPRPS mutant flies is affected by these defects. Overall, we uncovered an unexpected link between nucleotide metabolism and autophagy/lysosome function, providing a possible mechanism by which PRPS-dysfunction contributes to neurological disorders.
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Affiliation(s)
- Keemo Delos Santos
- Department of Biology, Developmental Biology Research Initiative, McGill University, Montreal, Quebec, Canada
| | - Minhee Kim
- Department of Biology, Developmental Biology Research Initiative, McGill University, Montreal, Quebec, Canada
| | - Christine Yergeau
- Department of Biology, Developmental Biology Research Initiative, McGill University, Montreal, Quebec, Canada
| | - Steve Jean
- Faculté de Médecine et des Sciences de la Santé, Département d’Anatomie et de Biologie Cellulaire, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Nam-Sung Moon
- Department of Biology, Developmental Biology Research Initiative, McGill University, Montreal, Quebec, Canada
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11
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Cho SJ, Lim HJ, Jo C, Park MH, Han C, Koh YH. Plasma ATG5 is increased in Alzheimer's disease. Sci Rep 2019; 9:4741. [PMID: 30894637 PMCID: PMC6427023 DOI: 10.1038/s41598-019-41347-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 03/07/2019] [Indexed: 02/06/2023] Open
Abstract
Alzheimer’s disease (AD) is a major cause of dementia. Growing evidence suggests that dysregulation of autophagy, a cellular mechanism essential for self-digestion of damaged proteins and organelles, is involved in neurological degenerative diseases including AD. Previously, we reported that autophagosomes are increased in the brains of AD mouse model. However, the plasma levels of autophagic markers have not yet been investigated in patients with AD. In this study, we investigated the expression of autophagy-related genes 5 and 12 (ATG5 and ATG12, respectively) in cells in vitro upon amyloid-beta (Aβ) treatment and in the plasma of AD patients. ATG5-ATG12 complex levels were increased in primary rat cortical neurons and human umbilical vein endothelial cells after Aβ treatment. Furthermore, we compared plasma from 69 patients with dementia, 82 patients with mild cognitive impairment (MCI), and 127 cognitively normal control participants. Plasma levels of ATG5 were significantly elevated in patients with dementia (149.3 ± 7.5 ng/mL) or MCI (152.9 ± 6.9 ng/mL) compared with the control subjects (129.0 ± 4.1 ng/mL) (p = 0.034, p = 0.016, respectively). Our results indicate that alterations in the plasma ATG5 levels might be a potential biomarker in patients at risk for AD.
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Affiliation(s)
- Sun-Jung Cho
- Division of Brain Diseases, Center for Biomedical Sciences, Korea National Institute of Health, 187 Osongsaengmyeong2-ro, Osong-eup, Heungdeok-gu, Cheongju-si, Chungcheongbuk-do, 28159, Korea
| | - Hyun Joung Lim
- Division of Brain Diseases, Center for Biomedical Sciences, Korea National Institute of Health, 187 Osongsaengmyeong2-ro, Osong-eup, Heungdeok-gu, Cheongju-si, Chungcheongbuk-do, 28159, Korea
| | - Chulman Jo
- Division of Brain Diseases, Center for Biomedical Sciences, Korea National Institute of Health, 187 Osongsaengmyeong2-ro, Osong-eup, Heungdeok-gu, Cheongju-si, Chungcheongbuk-do, 28159, Korea
| | - Moon Ho Park
- Departments of Neurology, Korea University, Ansan Hospital, 123 Jeokgeum-ro, Danwon-gu, Ansan-si, Gyeonggi-do, 15355, Korea
| | - Changsu Han
- Psychiatry, College of Medicine, Korea University, Ansan Hospital, 123 Jeokgeum-ro, Danwon-gu, Ansan-si, Gyeonggi-do, 15355, Korea
| | - Young Ho Koh
- Division of Brain Diseases, Center for Biomedical Sciences, Korea National Institute of Health, 187 Osongsaengmyeong2-ro, Osong-eup, Heungdeok-gu, Cheongju-si, Chungcheongbuk-do, 28159, Korea.
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12
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Spector C, Mele AR, Wigdahl B, Nonnemacher MR. Genetic variation and function of the HIV-1 Tat protein. Med Microbiol Immunol 2019; 208:131-169. [PMID: 30834965 DOI: 10.1007/s00430-019-00583-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 02/11/2019] [Indexed: 12/14/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) encodes a transactivator of transcription (Tat) protein, which has several functions that promote viral replication, pathogenesis, and disease. Amino acid variation within Tat has been observed to alter the functional properties of Tat and, depending on the HIV-1 subtype, may produce Tat phenotypes differing from viruses' representative of each subtype and commonly used in in vivo and in vitro experimentation. The molecular properties of Tat allow for distinctive functional activities to be determined such as the subcellular localization and other intracellular and extracellular functional aspects of this important viral protein influenced by variation within the Tat sequence. Once Tat has been transported into the nucleus and becomes engaged in transactivation of the long terminal repeat (LTR), various Tat variants may differ in their capacity to activate viral transcription. Post-translational modification patterns based on these amino acid variations may alter interactions between Tat and host factors, which may positively or negatively affect this process. In addition, the ability of HIV-1 to utilize or not utilize the transactivation response (TAR) element within the LTR, based on genetic variation and cellular phenotype, adds a layer of complexity to the processes that govern Tat-mediated proviral DNA-driven transcription and replication. In contrast, cytoplasmic or extracellular localization of Tat may cause pathogenic effects in the form of altered cell activation, apoptosis, or neurotoxicity. Tat variants have been shown to differentially induce these processes, which may have implications for long-term HIV-1-infected patient care in the antiretroviral therapy era. Future studies concerning genetic variation of Tat with respect to function should focus on variants derived from HIV-1-infected individuals to efficiently guide Tat-targeted therapies and elucidate mechanisms of pathogenesis within the global patient population.
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Affiliation(s)
- Cassandra Spector
- Department of Microbiology and Immunology, Drexel University College of Medicine, 245 N 15th St, Philadelphia, PA, 19102, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Anthony R Mele
- Department of Microbiology and Immunology, Drexel University College of Medicine, 245 N 15th St, Philadelphia, PA, 19102, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Brian Wigdahl
- Department of Microbiology and Immunology, Drexel University College of Medicine, 245 N 15th St, Philadelphia, PA, 19102, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
- Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Michael R Nonnemacher
- Department of Microbiology and Immunology, Drexel University College of Medicine, 245 N 15th St, Philadelphia, PA, 19102, USA.
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA.
- Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA.
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13
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Orssatto LBDR, Wiest MJ, Diefenthaeler F. Neural and musculotendinous mechanisms underpinning age-related force reductions. Mech Ageing Dev 2018; 175:17-23. [PMID: 29997056 DOI: 10.1016/j.mad.2018.06.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 06/21/2018] [Accepted: 06/28/2018] [Indexed: 01/02/2023]
Abstract
Ageing leads to substantial force production capacity reductions, which is an indicator of frailty and disability, and a mortality predictor in elders. Understanding the age-dependent neuromuscular mechanisms underlying force reductions can optimize healthcare professionals' exercise protocol choices for patients and allows researchers to investigate new interventions to mitigate these reductions. Our primary goal was to provide an updated review about the main neural and musculotendinous mechanisms underpinning age-related reductions in force capacity. Our secondary goal was to summarize how aerobic and strength training can lessen these age-related reductions. This review suggests that several steps in the force production pathway, from cortical to muscular mechanisms, are negatively affected by ageing. However, combining aerobic and strength training can attenuate these effects. Strength training (i.e. moderate to high- intensity, progressive volume, accentuated eccentric loading and fast concentric contraction velocity) can increase overall force production capacity by producing beneficial neural and musculotendinous adaptations. Additionally, aerobic training (i.e. moderate and high intensities) plays an essential role in preserving the structure and function of the neuromuscular system.
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Affiliation(s)
- Lucas Bet da Rosa Orssatto
- Laboratório de Biomecânica, Centro de Desportos, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Matheus Joner Wiest
- Toronto Rehabilitation Institute - UHN. Neural Engineering & Therapeutic Team, Toronto, Ontario, Canada
| | - Fernando Diefenthaeler
- Laboratório de Biomecânica, Centro de Desportos, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina, Brazil.
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14
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U1 small nuclear RNA overexpression implicates autophagic-lysosomal system associated with AD. Neurosci Res 2018; 136:48-55. [PMID: 29395359 DOI: 10.1016/j.neures.2018.01.006] [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] [Received: 10/13/2017] [Revised: 01/09/2018] [Accepted: 01/19/2018] [Indexed: 11/20/2022]
Abstract
Recently, we reported that presenilin 1 considerably increased the expression level of U1 small nuclear RNA (snRNA) accompanied with the adverse change of amyloid precursor protein (APP) expression, β-amyloid (Aβ) production and cell apoptosis. In the present study, it was found that U1 snRNA overexpression significantly elevated the expression level of autophagy. Moreover, rapamycin further enhanced the Aβ production and cell apoptosis, whereas these processes were effectively inhibited by 3-MA. Acridine orange staining images showed that U1 snRNA overexpression not only activated autophagy pathway, but also led to the autophagic-lysosomal system dysfunction in cells. Immunofluorescence assay showed autophagic vacuoles localization with APP, which was the precursor protein of main component of toxic protein in AD. Meanwhile, the superoxide dismutase activity was remarkably decreased and MDA level was significantly increased by U1 snRNA overexpression in cells, suggesting that there was a possible pathway to elucidate how the U1 snRNA overexpression induced cell damage. We further found that U1 snRNA overexpression altered lysosomal biogenesis and autophagic-lysosomal fusion. In combination with our previous results, it suggests that the malfunction of autophagy pathway provides important insight into molecular mechanisms of augment the aggregation of Aβ and induction of cell apoptosis contributed to AD.
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15
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Rahman N, Ramos-Espiritu L, Milner TA, Buck J, Levin LR. Soluble adenylyl cyclase is essential for proper lysosomal acidification. J Gen Physiol 2017; 148:325-39. [PMID: 27670898 PMCID: PMC5037342 DOI: 10.1085/jgp.201611606] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 09/08/2016] [Indexed: 01/07/2023] Open
Abstract
Lysosomes, the degradative organelles of the endocytic and autophagic pathways, function at an acidic pH. Lysosomes are acidified by the proton-pumping vacuolar ATPase (V-ATPase), but the molecular processes that set the organelle's pH are not completely understood. In particular, pH-sensitive signaling enzymes that can regulate lysosomal acidification in steady-state physiological conditions have yet to be identified. Soluble adenylyl cyclase (sAC) is a widely expressed source of cAMP that serves as a physiological pH sensor in cells. For example, in proton-secreting epithelial cells, sAC is responsible for pH-dependent translocation of V-ATPase to the luminal surface. Here we show genetically and pharmacologically that sAC is also essential for lysosomal acidification. In the absence of sAC, V-ATPase does not properly localize to lysosomes, lysosomes fail to fully acidify, lysosomal degradative capacity is diminished, and autophagolysosomes accumulate.
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Affiliation(s)
- Nawreen Rahman
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065 Graduate Program in Neuroscience, Weill Cornell Medical College, New York, NY 10065
| | | | - Teresa A Milner
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065 Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY 10065
| | - Jochen Buck
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065
| | - Lonny R Levin
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065
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16
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Kettwig M, Ohlenbusch A, Jung K, Steinfeld R, Gärtner J. Cathepsin D Polymorphism C224T in Childhood-Onset Neurodegenerative Disorders: No Impact for Childhood Dementia. J Pediatr Genet 2017; 7:14-18. [PMID: 29441216 DOI: 10.1055/s-0037-1607341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 09/14/2017] [Indexed: 10/18/2022]
Abstract
Compromised lysosomal functioning has been identified as a major risk factor for neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. Furthermore, the association between a defined cathepsin D ( CTSD ) polymorphism and a higher risk of sporadic Alzheimer's disease has been established for particular populations. Here, we analyzed 189 children with rare neurodegenerative disease for carrying the T-allele by polymerase chain reaction-restriction fragment length polymorphism. We found no statistical differences in genotype and allele frequencies between the neurodegenerative group and European descent participants of genetic studies using the Cochran-Armitage's trend test. In contrast to adult-onset neurodegenerative diseases, analysis of clinical datasets of children carrying the T-allele did not demonstrate differences to the general disease group.
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Affiliation(s)
- Matthias Kettwig
- Department of Pediatrics and Pediatric Neurology, University Medical Center Göttingen, Georg August University Göttingen, Göttingen, Germany
| | - Andreas Ohlenbusch
- Department of Pediatrics and Pediatric Neurology, University Medical Center Göttingen, Georg August University Göttingen, Göttingen, Germany
| | - Klaus Jung
- Department of Medical Statistics, University Medical Center Göttingen, Georg August University Göttingen, Göttingen, Germany.,Intitute for Animal Breeding and Genetics, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Robert Steinfeld
- Department of Pediatrics and Pediatric Neurology, University Medical Center Göttingen, Georg August University Göttingen, Göttingen, Germany
| | - Jutta Gärtner
- Department of Pediatrics and Pediatric Neurology, University Medical Center Göttingen, Georg August University Göttingen, Göttingen, Germany
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17
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Nixon RA. Amyloid precursor protein and endosomal-lysosomal dysfunction in Alzheimer's disease: inseparable partners in a multifactorial disease. FASEB J 2017; 31:2729-2743. [PMID: 28663518 DOI: 10.1096/fj.201700359] [Citation(s) in RCA: 222] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 04/21/2017] [Indexed: 12/15/2022]
Abstract
Abnormalities of the endosomal-lysosomal network (ELN) are a signature feature of Alzheimer's disease (AD). These include the earliest known cytopathology that is specific to AD and that affects endosomes and induces the progressive failure of lysosomes, each of which are directly linked by distinct mechanisms to neurodegeneration. The origins of ELN dysfunction and β-amyloidogenesis closely overlap, which reflects their common genetic basis, the established early involvement of endosomes and lysosomes in amyloid precursor protein (APP) processing and clearance, and the pathologic effect of certain APP metabolites on ELN functions. Genes that promote β-amyloidogenesis in AD (APP, PSEN1/2, and APOE4) have primary effects on ELN function. The importance of primary ELN dysfunction to pathogenesis is underscored by the mutations in more than 35 ELN-related genes that, thus far, are known to cause familial neurodegenerative diseases even though different pathogenic proteins may be involved. In this article, I discuss growing evidence that implicates AD gene-driven ELN disruptions as not only the antecedent pathobiology that underlies β-amyloidogenesis but also as the essential partner with APP and its metabolites that drive the development of AD, including tauopathy, synaptic dysfunction, and neurodegeneration. The striking amelioration of diverse deficits in animal AD models by remediating ELN dysfunction further supports a need to integrate APP and ELN relationships, including the role of amyloid-β, into a broader conceptual framework of how AD arises, progresses, and may be effectively therapeutically targeted.-Nixon, R. A. Amyloid precursor protein and endosomal-lysosomal dysfunction in Alzheimer's disease: inseparable partners in a multifactorial disease.
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Affiliation(s)
- Ralph A Nixon
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, New York, USA; .,Department of Psychiatry and Department of Cell Biology, New York University Langone Medical Center, New York, New York, USA
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18
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Farizatto KLG, Ikonne US, Almeida MF, Ferrari MFR, Bahr BA. Aβ42-mediated proteasome inhibition and associated tau pathology in hippocampus are governed by a lysosomal response involving cathepsin B: Evidence for protective crosstalk between protein clearance pathways. PLoS One 2017; 12:e0182895. [PMID: 28797057 PMCID: PMC5552263 DOI: 10.1371/journal.pone.0182895] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 07/26/2017] [Indexed: 12/12/2022] Open
Abstract
Impaired protein clearance likely increases the risk of protein accumulation disorders including Alzheimer’s disease (AD). Protein degradation through the proteasome pathway decreases with age and in AD brains, and the Aβ42 peptide has been shown to impair proteasome function in cultured cells and in a cell-free model. Here, Aβ42 was studied in brain tissue to measure changes in protein clearance pathways and related secondary pathology. Oligomerized Aβ42 (0.5–1.5 μM) reduced proteasome activity by 62% in hippocampal slice cultures over a 4-6-day period, corresponding with increased tau phosphorylation and reduced synaptophysin levels. Interestingly, the decrease in proteasome activity was associated with a delayed inverse effect, >2-fold increase, regarding lysosomal cathepsin B (CatB) activity. The CatB enhancement did not correspond with the Aβ42-mediated phospho-tau alterations since the latter occurred prior to the CatB response. Hippocampal slices treated with the proteasome inhibitor lactacystin also exhibited an inverse effect on CatB activity with respect to diminished proteasome function. Lactacystin caused earlier CatB enhancement than Aβ42, and no correspondence was evident between up-regulated CatB levels and the delayed synaptic pathology indicated by the loss of pre- and postsynaptic markers. Contrasting the inverse effects on the proteasomal and lysosomal pathways by Aβ42 and lactacystin, such were not found when CatB activity was up-regulated two-fold with Z-Phe-Ala-diazomethylketone (PADK). Instead of an inverse decline, proteasome function was increased marginally in PADK-treated hippocampal slices. Unexpectedly, the proteasomal augmentation was significantly pronounced in Aβ42-compromised slices, while absent in lactacystin-treated tissue, resulting in >2-fold improvement for nearly complete recovery of proteasome function by the CatB-enhancing compound. The PADK treatment also reduced Aβ42-mediated tau phosphorylation and synaptic marker declines, corresponding with the positive modulation of both proteasome activity and the lysosomal CatB enzyme. These findings indicate that proteasomal stress contributes to AD-type pathogenesis and that governing such pathology occurs through crosstalk between the two protein clearance pathways.
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Affiliation(s)
- Karen L. G. Farizatto
- Biotechnology Research and Training Center, William C. Friday Laboratory, University of North Carolina—Pembroke, Pembroke, North Carolina, United States of America
- Department of Genetics and Evolutionary Biology, Institute for Biosciences, University of Sao Paulo, Sao Paulo, Sao Paulo, Brazil
| | - Uzoma S. Ikonne
- Biotechnology Research and Training Center, William C. Friday Laboratory, University of North Carolina—Pembroke, Pembroke, North Carolina, United States of America
| | - Michael F. Almeida
- Biotechnology Research and Training Center, William C. Friday Laboratory, University of North Carolina—Pembroke, Pembroke, North Carolina, United States of America
| | - Merari F. R. Ferrari
- Department of Genetics and Evolutionary Biology, Institute for Biosciences, University of Sao Paulo, Sao Paulo, Sao Paulo, Brazil
| | - Ben A. Bahr
- Biotechnology Research and Training Center, William C. Friday Laboratory, University of North Carolina—Pembroke, Pembroke, North Carolina, United States of America
- * E-mail:
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19
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Salvalaio M, D'Avanzo F, Rigon L, Zanetti A, D'Angelo M, Valle G, Scarpa M, Tomanin R. Brain RNA-Seq Profiling of the Mucopolysaccharidosis Type II Mouse Model. Int J Mol Sci 2017; 18:ijms18051072. [PMID: 28513549 PMCID: PMC5454982 DOI: 10.3390/ijms18051072] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 05/05/2017] [Accepted: 05/08/2017] [Indexed: 11/16/2022] Open
Abstract
Lysosomal storage disorders (LSDs) are a group of about 50 genetic metabolic disorders, mainly affecting children, sharing the inability to degrade specific endolysosomal substrates. This results in failure of cellular functions in many organs, including brain that in most patients may go through progressive neurodegeneration. In this study, we analyzed the brain of the mouse model for Hunter syndrome, a LSD mostly presenting with neurological involvement. Whole transcriptome analysis of the cerebral cortex and midbrain/diencephalon/hippocampus areas was performed through RNA-seq. Genes known to be involved in several neurological functions showed a significant differential expression in the animal model for the disease compared to wild type. Among the pathways altered in both areas, axon guidance, calcium homeostasis, synapse and neuroactive ligand-receptor interaction, circadian rhythm, neuroinflammation and Wnt signaling were the most significant. Application of RNA sequencing to dissect pathogenic alterations of complex syndromes allows to photograph perturbations, both determining and determined by these disorders, which could simultaneously occur in several metabolic and biochemical pathways. Results also emphasize the common, altered pathways between neurodegenerative disorders affecting elderly and those associated with pediatric diseases of genetic origin, perhaps pointing out a general common course for neurodegeneration, independent from the primary triggering cause.
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Affiliation(s)
- Marika Salvalaio
- Women's and Children's Health Department, University of Padova, Via Giustiniani 3, 35128 Padova, Italy.
- Pediatric Research Institute-Città della Speranza, Corso Stati Uniti 4, 35127 Padova, Italy.
| | - Francesca D'Avanzo
- Women's and Children's Health Department, University of Padova, Via Giustiniani 3, 35128 Padova, Italy.
- Pediatric Research Institute-Città della Speranza, Corso Stati Uniti 4, 35127 Padova, Italy.
| | - Laura Rigon
- Women's and Children's Health Department, University of Padova, Via Giustiniani 3, 35128 Padova, Italy.
- Pediatric Research Institute-Città della Speranza, Corso Stati Uniti 4, 35127 Padova, Italy.
| | - Alessandra Zanetti
- Women's and Children's Health Department, University of Padova, Via Giustiniani 3, 35128 Padova, Italy.
- Pediatric Research Institute-Città della Speranza, Corso Stati Uniti 4, 35127 Padova, Italy.
| | - Michela D'Angelo
- CRIBI Biotechnology Center, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy.
| | - Giorgio Valle
- CRIBI Biotechnology Center, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy.
| | - Maurizio Scarpa
- Women's and Children's Health Department, University of Padova, Via Giustiniani 3, 35128 Padova, Italy.
- Pediatric Research Institute-Città della Speranza, Corso Stati Uniti 4, 35127 Padova, Italy.
- Brains for Brain Foundation, Via Giustiniani 3, 35128 Padova, Italy.
| | - Rosella Tomanin
- Women's and Children's Health Department, University of Padova, Via Giustiniani 3, 35128 Padova, Italy.
- Pediatric Research Institute-Città della Speranza, Corso Stati Uniti 4, 35127 Padova, Italy.
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20
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Lv HJ, Zhang XT, Wang S, Xing GW. Assembly of BODIPY-carbazole dyes with liposomes to fabricate fluorescent nanoparticles for lysosomal bioimaging in living cells. Analyst 2017; 142:603-607. [DOI: 10.1039/c6an02705a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A strategy was developed to change an ACQ organic dye into a fluorescent nanoparticle probe for lysosomal bioimaging.
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Affiliation(s)
- Hai-juan Lv
- Department of Chemistry
- Beijing Normal University
- Beijing 100875
- China
| | - Xiao-tai Zhang
- Department of Chemistry
- Beijing Normal University
- Beijing 100875
- China
| | - Shu Wang
- Key Laboratory of Organic Solids
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Guo-wen Xing
- Department of Chemistry
- Beijing Normal University
- Beijing 100875
- China
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21
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Iowa Mutant Apolipoprotein A-I (ApoA-IIowa) Fibrils Target Lysosomes. Sci Rep 2016; 6:30391. [PMID: 27464946 PMCID: PMC4964564 DOI: 10.1038/srep30391] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 06/30/2016] [Indexed: 01/01/2023] Open
Abstract
The single amino acid mutation G26R in human apolipoprotein A-I (apoA-IIowa) is the first mutation that was associated with familial AApoA1 amyloidosis. The N-terminal fragments (amino acid residues 1–83) of apoA-I containing this mutation deposit as amyloid fibrils in patients’ tissues and organs, but the mechanisms of cellular degradation and cytotoxicity have not yet been clarified. In this study, we demonstrated degradation of apoA-IIowa fibrils via the autophagy-lysosomal pathway in human embryonic kidney 293 cells. ApoA-IIowa fibrils induced an increase in lysosomal pH and the cytosolic release of the toxic lysosomal protease cathepsin B. The mitochondrial dysfunction caused by apoA-IIowa fibrils depended on cathepsin B and was ameliorated by increasing the degradation of apoA-IIowa fibrils. Thus, although apoA-IIowa fibril transport to lysosomes and fibril degradation in lysosomes may have occurred, the presence of an excess number of apoA-IIowa fibrils, more than the lysosomes could degrade, may be detrimental to cells. Our results thus provide evidence that the target of apoA-IIowa fibrils is lysosomes, and we thereby gained a novel insight into the mechanism of AApoA1 amyloidosis.
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22
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Hwang S, Disatnik MH, Mochly-Rosen D. Impaired GAPDH-induced mitophagy contributes to the pathology of Huntington's disease. EMBO Mol Med 2016; 7:1307-26. [PMID: 26268247 PMCID: PMC4604685 DOI: 10.15252/emmm.201505256] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mitochondrial dysfunction is implicated in multiple neurodegenerative diseases. In order to maintain a healthy population of functional mitochondria in cells, defective mitochondria must be properly eliminated by lysosomal machinery in a process referred to as mitophagy. Here, we uncover a new molecular mechanism underlying mitophagy driven by glyceraldehyde-3-phosphate dehydrogenase (GAPDH) under the pathological condition of Huntington’s disease (HD) caused by expansion of polyglutamine repeats. Expression of expanded polyglutamine tracts catalytically inactivates GAPDH (iGAPDH), which triggers its selective association with damaged mitochondria in several cell culture models of HD. Through this mechanism, iGAPDH serves as a signaling molecule to induce direct engulfment of damaged mitochondria into lysosomes (micro-mitophagy). However, abnormal interaction of mitochondrial GAPDH with long polyglutamine tracts stalled GAPDH-mediated mitophagy, leading to accumulation of damaged mitochondria, and increased cell death. We further demonstrated that overexpression of inactive GAPDH rescues this blunted process and enhances mitochondrial function and cell survival, indicating a role for GAPDH-driven mitophagy in the pathology of HD.
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Affiliation(s)
- Sunhee Hwang
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Marie-Hélène Disatnik
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Daria Mochly-Rosen
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
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23
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Meduri G, Guillemeau K, Dounane O, Sazdovitch V, Duyckaerts C, Chambraud B, Baulieu EE, Giustiniani J. Caspase-cleaved Tau-D(421) is colocalized with the immunophilin FKBP52 in the autophagy-endolysosomal system of Alzheimer's disease neurons. Neurobiol Aging 2016; 46:124-37. [PMID: 27479154 DOI: 10.1016/j.neurobiolaging.2016.06.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 04/27/2016] [Accepted: 06/24/2016] [Indexed: 01/06/2023]
Abstract
Pathologic modifications of the Tau protein leading to neurofibrillary tangle (NFT) formation are a common feature of a wide range of neurodegenerative diseases known as tauopathies, which include Alzheimer's disease (AD). We previously showed that the immunophilin FKBP52 physically and functionally interacts with Tau, and we recently reported that FKBP52 levels are abnormally low in AD patients' brains. To decipher the mechanism of FKBP52 decrease in AD brains, we performed multiple labeling immunohistofluorescence and lysosomal purification using postmortem brain samples of healthy controls (n = 8) and AD (n = 20) patients. Confocal analysis revealed that FKBP52 localizes to the endolysosomal system. We also report FKBP52 colocalization with the truncated Tau-D(421) in the autophagy-endolysosomal system in some AD neurons and that the decrease of FKBP52 correlates with NFT formation. Additional experiments of autophagy inhibition in Tau-inducible SH-SY5Y cells allowed demonstrating FKBP52 release in the extracellular milieu. Our findings point out the possibility that FKBP52 could be abnormally released from NFTs negative neurons in AD brains in correlation with the early pathologic Tau-D(421) neuronal accumulation.
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Affiliation(s)
- Geri Meduri
- INSERM, Unité mixte de recherche 1195, Université Paris-Saclay, Le Kremlin Bicêtre, France
| | - Kevin Guillemeau
- INSERM, Unité mixte de recherche 1195, Université Paris-Saclay, Le Kremlin Bicêtre, France
| | - Omar Dounane
- INSERM, Unité mixte de recherche 1195, Université Paris-Saclay, Le Kremlin Bicêtre, France
| | - Véronique Sazdovitch
- Laboratoire de Neuropathologie Escourolle, Hôpital de La Salpêtrière, AP-HP, Paris, France
| | - Charles Duyckaerts
- Laboratoire de Neuropathologie Escourolle, Hôpital de La Salpêtrière, AP-HP, Paris, France
| | - Béatrice Chambraud
- INSERM, Unité mixte de recherche 1195, Université Paris-Saclay, Le Kremlin Bicêtre, France
| | - Etienne Emile Baulieu
- INSERM, Unité mixte de recherche 1195, Université Paris-Saclay, Le Kremlin Bicêtre, France.
| | - Julien Giustiniani
- INSERM, Unité mixte de recherche 1195, Université Paris-Saclay, Le Kremlin Bicêtre, France.
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Transcription Factor EB Is Selectively Reduced in the Nuclear Fractions of Alzheimer's and Amyotrophic Lateral Sclerosis Brains. NEUROSCIENCE JOURNAL 2016; 2016:4732837. [PMID: 27433468 PMCID: PMC4940567 DOI: 10.1155/2016/4732837] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/03/2016] [Accepted: 06/07/2016] [Indexed: 12/11/2022]
Abstract
Multiple studies suggest that autophagy is strongly dysregulated in Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS), as evidenced by accumulation of numerous autophagosomes, lysosomes with discontinuous membranes, and aggregated proteins in the patients' brains. Transcription factor EB (TFEB) was recently discovered to be a master regulator of lysosome biogenesis and autophagy. To examine whether aberrant autophagy in AD and ALS is due to alterations in TFEB expression, we systematically quantified the levels of TFEB in these brains by immunoblotting. Interestingly, cytoplasmic fractions of AD brains showed increased levels of normalized (to tubulin) TFEB only at Braak stage IV (61%, p < 0.01). Most importantly, normalized (to lamin) TFEB levels in the nuclear fractions were consistently reduced starting from Braak stage IV (52%, p < 0.01), stage V (67%, p < 0.01), and stage VI (85%, p < 0.01) when compared to normal control (NC) brains. In the ALS brains also, nuclear TFEB levels were reduced by 62% (p < 0.001). These data suggest that nuclear TFEB is selectively lost in ALS as well as AD brains, in which TFEB reduction was Braak-stage-dependent. Taken together, the observed reductions in TFEB protein levels may be responsible for the widely reported autophagy defects in these disorders.
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25
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TFEB Overexpression in the P301S Model of Tauopathy Mitigates Increased PHF1 Levels and Lipofuscin Puncta and Rescues Memory Deficits. eNeuro 2016; 3:eN-NWR-0042-16. [PMID: 27257626 PMCID: PMC4876487 DOI: 10.1523/eneuro.0042-16.2016] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 05/05/2016] [Accepted: 05/06/2016] [Indexed: 12/22/2022] Open
Abstract
Transcription factor EB (TFEB) was recently shown to be a master regulator of autophagy lysosome pathway. Here, we successfully generated and characterized transgenic mice overexpressing flag-TFEB. Enhanced autophagy in the flag-TFEB transgenic mice was confirmed by an increase in the cellular autophagy markers, as determined by both immunoblots and transmission electron microscopy. Surprisingly, in the flag-TFEB mice we observed increased activity of senescence-associated β-galactosidase by ∼66% of neurons in the cortex (p < 0.001) and 73% of neurons in the hippocampus (p < 0.001). More importantly, flag-TFEB expression remarkably reduced the levels of paired-helical filament (PHF)-tau from 372% in the P301S model of tauopathy to 171% (p < 0.001) in the cortex, and from 436% to 212% (p < 0.001) in the hippocampus. Significantly, reduced levels of NeuN in the cortex (38%, p < 0.001) and hippocampus (25%, p < 0.05) of P301S mice were almost completely restored to WT levels in the P301S/flag-TFEB double-transgenic mice. Also, levels of spinophilin in both the cortex (p < 0.001) and hippocampus (p < 0.001) were restored almost to WT levels. Most importantly, the age-associated lipofuscin granules, which are generally presumed to be nondegradable, were reduced by 57% (p < 0.001) in the cortex and by 55% (p < 0.001) in the hippocampus in the double-transgenic mice. Finally, TFEB overexpression in the P301S mice markedly reversed learning deficits in terms of spatial memory (Barnes maze), as well as working and reference memories (T maze). These data suggest that the overexpression of TFEB can reliably enhance autophagy in vivo, reduce levels of PHF-tau, and thereby reverse the deposition of lipofuscin granules and memory deficits.
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26
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Direct Observation of α-Synuclein Amyloid Aggregates in Endocytic Vesicles of Neuroblastoma Cells. PLoS One 2016; 11:e0153020. [PMID: 27105068 PMCID: PMC4841506 DOI: 10.1371/journal.pone.0153020] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 03/21/2016] [Indexed: 11/19/2022] Open
Abstract
Aggregation of α-synuclein has been linked to both familial and sporadic Parkinson's disease. Recent studies suggest that α-synuclein aggregates may spread from cell to cell and raise questions about the propagation of neurodegeneration. While continuous progress has been made characterizing α-synuclein aggregates in vitro, there is a lack of information regarding the structure of these species inside the cells. Here, we use confocal fluorescence microscopy in combination with direct stochastic optical reconstruction microscopy, dSTORM, to investigate α-synuclein uptake when added exogenously to SH-SY5Y neuroblastoma cells, and to probe in situ morphological features of α-synuclein aggregates with near nanometer resolution. We demonstrate that using dSTORM, it is possible to follow noninvasively the uptake of extracellularly added α-synuclein aggregates by the cells. Once the aggregates are internalized, they move through the endosomal pathway and accumulate in lysosomes to be degraded. Our dSTORM data show that α-synuclein aggregates remain assembled after internalization and they are shortened as they move through the endosomal pathway. No further aggregation was observed inside the lysosomes as speculated in the literature, nor in the cytoplasm of the cells. Our study thus highlights the super-resolution capability of dSTORM to follow directly the endocytotic uptake of extracellularly added amyloid aggregates and to probe the morphology of in situ protein aggregates even when they accumulate in small vesicular compartments.
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27
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Coutinho MF, Alves S. From rare to common and back again: 60years of lysosomal dysfunction. Mol Genet Metab 2016; 117:53-65. [PMID: 26422115 DOI: 10.1016/j.ymgme.2015.08.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 08/12/2015] [Accepted: 08/12/2015] [Indexed: 01/12/2023]
Abstract
Sixty years after its discovery, the lysosome is no longer considered as cell's waste bin but as an organelle playing a central role in cell metabolism. Besides its well known association with lysosomal storage disorders (mostly rare and life-threatening diseases), recent data have shown that the lysosome is also a player in some of the most common conditions of our time; and, perhaps even most important, it is not only a target for orphan drugs (rare disease therapeutic approaches) but also a putative target to treat patients suffering from common complex diseases worldwide. Here we review the striking associations linking rare lysosomal storage disorders such as the well-known Gaucher disease, or even the recently discovered, extremely rare Neuronal Ceroid Lipofuscinosis-11 and some of the most frequent, multifaceted and complex disorders of modern society such as cancer, Parkinson's disease and frontotemporal lobar degeneration.
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Affiliation(s)
| | - Sandra Alves
- Research and Development Unit, Department of Human Genetics, INSA, Portugal
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28
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Haploinsufficiency of cathepsin D leads to lysosomal dysfunction and promotes cell-to-cell transmission of α-synuclein aggregates. Cell Death Dis 2015; 6:e1901. [PMID: 26448324 PMCID: PMC4632307 DOI: 10.1038/cddis.2015.283] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 07/06/2015] [Accepted: 07/22/2015] [Indexed: 12/17/2022]
Abstract
Lysosomal dysfunction has been implicated both pathologically and genetically in neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease (PD). Lysosomal gene deficiencies cause lysosomal storage disorders, many of which involve neurodegeneration. Heterozygous mutations of some of these genes, such as GBA1, are associated with PD. CTSD is the gene encoding Cathepsin D (CTSD), a lysosomal protein hydrolase, and homozygous CTSD deficiency results in neuronal ceroid-lipofuscinosis, which is characterized by the early onset, progressive neurodegeneration. CTSD deficiency was also associated with deposition of α-synuclein aggregates, the hallmark of PD. However, whether partial deficiency of CTSD has a role in the late onset progressive neurodegenerative disorders, including PD, remains unknown. Here, we generated cell lines harboring heterozygous nonsense mutations in CTSD with genomic editing using the zinc finger nucleases. Heterozygous mutation in CTSD resulted in partial loss of CTSD activity, leading to reduced lysosomal activity. The CTSD mutation also resulted in increased accumulation of intracellular α-synuclein aggregates and the secretion of the aggregates. When α-synuclein was introduced in the media, internalized α-synuclein aggregates accumulated at higher levels in CTSD+/− cells than in the wild-type cells. Consistent with these results, transcellular transmission of α-synuclein aggregates was increased in CTSD+/− cells. The increased transmission of α-synuclein aggregates sustained during the successive passages of CTSD+/− cells. These results suggest that partial loss of CTSD activity is sufficient to cause a reduction in lysosomal function, which in turn leads to α-synuclein aggregation and propagation of the aggregates.
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29
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Upadhyay A, Amanullah A, Chhangani D, Mishra R, Prasad A, Mishra A. Mahogunin Ring Finger-1 (MGRN1), a Multifaceted Ubiquitin Ligase: Recent Unraveling of Neurobiological Mechanisms. Mol Neurobiol 2015; 53:4484-96. [PMID: 26255182 DOI: 10.1007/s12035-015-9379-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 07/27/2015] [Indexed: 11/29/2022]
Abstract
In healthy cell, inappropriate accumulation of poor or damaged proteins is prevented by cellular quality control system. Autophagy and ubiquitin proteasome system (UPS) provides regular cytoprotection against proteotoxicity induced by abnormal or disruptive proteins. E3 ubiquitin ligases are crucial components in this defense mechanism. Mahogunin Ring Finger-1 (MGRN1), an E3 ubiquitin ligase of the Really Interesting New Gene (RING) finger family, plays a pivotal role in many biological and cellular mechanisms. Previous findings indicate that lack of functions of MGRN1 can cause spongiform neurodegeneration, congenital heart defects, abnormal left-right patterning, and mitochondrial dysfunctions in mice brains. However, the detailed molecular pathomechanism of MGRN1 in cellular functions and diseases is not well known. This article comprehensively represents the molecular nature, characterization, and functions of MGRN1; we also summarize possible beneficiary aspects of this novel E3 ubiquitin ligase. Here, we review recent literature on the role of MGRN1 in the neuro-pathobiological mechanisms, with precise focus on the processes of neurodegeneration, and thereby propose new lines of potential targets for therapeutic intervention.
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Affiliation(s)
- Arun Upadhyay
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, 342011, India
| | - Ayeman Amanullah
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, 342011, India
| | - Deepak Chhangani
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, 342011, India
| | - Ribhav Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, 342011, India
| | - Amit Prasad
- School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh, 175005, India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, 342011, India.
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30
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Barage SH, Sonawane KD. Amyloid cascade hypothesis: Pathogenesis and therapeutic strategies in Alzheimer's disease. Neuropeptides 2015; 52:1-18. [PMID: 26149638 DOI: 10.1016/j.npep.2015.06.008] [Citation(s) in RCA: 365] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 06/24/2015] [Accepted: 06/24/2015] [Indexed: 01/08/2023]
Abstract
Alzheimer's disease is an irreversible, progressive neurodegenerative disorder. Various therapeutic approaches are being used to improve the cholinergic neurotransmission, but their role in AD pathogenesis is still unknown. Although, an increase in tau protein concentration in CSF has been described in AD, but several issues remains unclear. Extensive and accurate analysis of CSF could be helpful to define presence of tau proteins in physiological conditions, or released during the progression of neurodegenerative disease. The amyloid cascade hypothesis postulates that the neurodegeneration in AD caused by abnormal accumulation of amyloid beta (Aβ) plaques in various areas of the brain. The amyloid hypothesis has continued to gain support over the last two decades, particularly from genetic studies. Therefore, current research progress in several areas of therapies shall provide an effective treatment to cure this devastating disease. This review critically evaluates general biochemical and physiological functions of Aβ directed therapeutics and their relevance.
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Affiliation(s)
- Sagar H Barage
- Department of Biotechnology, Shivaji University, Kolhapur 416004, Maharashtra (M.S.), India
| | - Kailas D Sonawane
- Structural Bioinformatics Unit, Department of Biochemistry, Shivaji University, Kolhapur 416004, Maharashtra (M.S.), India; Department of Microbiology, Shivaji University, Kolhapur 416004, Maharashtra (M.S.), India.
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31
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Loss of glucocerebrosidase 1 activity causes lysosomal dysfunction and α-synuclein aggregation. Exp Mol Med 2015; 47:e153. [PMID: 25813221 PMCID: PMC4351412 DOI: 10.1038/emm.2014.128] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 11/27/2014] [Accepted: 12/04/2014] [Indexed: 12/14/2022] Open
Abstract
Lysosomal dysfunction is a common pathological feature of neurodegenerative diseases. GTP-binding protein type A1 (GBA1) encodes β-glucocerebrosidase 1 (GCase 1), a lysosomal hydrolase. Homozygous mutations in GBA1 cause Gaucher disease, the most common lysosomal storage disease, while heterozygous mutations are strong risk factors for Parkinson's disease. However, whether loss of GCase 1 activity is sufficient for lysosomal dysfunction has not been clearly determined. Here, we generated human neuroblastoma cell lines with nonsense mutations in the GBA1 gene using zinc-finger nucleases. Depending on the site of mutation, GCase 1 activity was lost or maintained. The cell line with GCase 1 deficiency showed indications of lysosomal dysfunction, such as accumulation of lysosomal substrates, reduced dextran degradation and accumulation of enlarged vacuolar structures. In contrast, the cell line with C-terminal truncation of GCase 1 but with intact GCase 1 activity showed normal lysosomal function. When α-synuclein was overexpressed, accumulation and secretion of insoluble aggregates increased in cells with GCase 1 deficiency but did not change in mutant cells with normal GCase 1 activity. These results demonstrate that loss of GCase 1 activity is sufficient to cause lysosomal dysfunction and accumulation of α-synuclein aggregates.
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32
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Prada CE, Grabowski GA. Neuronopathic lysosomal storage diseases: clinical and pathologic findings. ACTA ACUST UNITED AC 2014; 17:226-46. [PMID: 23798011 DOI: 10.1002/ddrr.1116] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/17/2012] [Indexed: 12/20/2022]
Abstract
BACKGROUND The lysosomal-autophagocytic system diseases (LASDs) affect multiple body systems including the central nervous system (CNS). The progressive CNS pathology has its onset at different ages, leading to neurodegeneration and early death. METHODS Literature review provided insight into the current clinical neurological findings, phenotypic spectrum, and pathogenic mechanisms of LASDs with primary neurological involvement. CONCLUSIONS CNS signs and symptoms are variable and related to the disease-specific underlying pathogenesis. LAS dysfunction leads to diverse global cellular consequences in the CNS ranging from specific axonal and dendritic abnormalities to neuronal death. Pathogenic mechanisms for disease progression vary from impaired autophagy, massive storage, regional involvement, to end-stage inflammation. Some of these features are also found in adult neurodegenerative disorders, for example, Parkinson's and Alzheimer's diseases. Lack of effective therapies is a significant unmet medical need.
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Affiliation(s)
- Carlos E Prada
- Division of Human Genetics, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Ohio, USA
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33
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Chen X, Hui L, Soliman ML, Geiger JD. Altered Cholesterol Intracellular Trafficking and the Development of Pathological Hallmarks of Sporadic AD. ACTA ACUST UNITED AC 2014; 1. [PMID: 25621310 DOI: 10.13188/2376-922x.1000002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Compared to the rare familial early onset Alzheimer's disease (AD) that results from gene mutations in AbPP and presenilin-1, the pathogenesis of sporadic AD is much more complex and is believed to result from complex interactions between nutritional, environmental, epigenetic and genetic factors. Among those factors, the presence APOE4 is still the single strongest genetic risk factor for sporadic AD. However, the exact underlying mechanism whereby apoE4 contributes to the pathogenesis of sporadic AD remains unclear. Here, we discuss how altered cholesterol intracellular trafficking as a result of apoE4 might contribute to the development of pathological hallmarks of AD including brain deposition of amyloid beta (Ab), neurofibrillary tangles, and synaptic dysfunction.
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34
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Pišlar A, Kos J. Cysteine cathepsins in neurological disorders. Mol Neurobiol 2013; 49:1017-30. [PMID: 24234234 DOI: 10.1007/s12035-013-8576-6] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Accepted: 10/21/2013] [Indexed: 12/13/2022]
Abstract
Increased proteolytic activity is a hallmark of several pathological processes, including neurodegeneration. Increased expression and activity of cathepsins, lysosomal cysteine proteases, during degeneration of the central nervous system is frequently reported. Recent studies reveal that a disturbed balance of their enzymatic activities is the first insult in brain aging and age-related diseases. Leakage of cathepsins from lysosomes, due to their membrane permeability, and activation of pro-apoptotic factors additionally contribute to neurodegeneration. Furthermore, in inflammation-induced neurodegeneration the cathepsins expressed in activated microglia play a pivotal role in neuronal death. The proteolytic activity of cysteine cathepsins is controlled by endogenous protein inhibitors-the cystatins-which evidently fail to perform their function in neurodegenerative processes. Exogenous synthetic inhibitors, which may augment their inhibitory potential, are considered as possible therapeutic tools for the treatment of neurological disorders.
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Affiliation(s)
- Anja Pišlar
- Department of Pharmaceutical Biology, Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000, Ljubljana, Slovenia,
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Convergence of synapses, endosomes, and prions in the biology of neurodegenerative diseases. Int J Cell Biol 2013; 2013:141083. [PMID: 24307901 PMCID: PMC3838826 DOI: 10.1155/2013/141083] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 09/23/2013] [Indexed: 11/17/2022] Open
Abstract
Age-related misfolding and aggregation of disease-linked proteins in selective brain regions is a characteristic of neurodegenerative diseases. Although neuropathological aggregates that characterize these various diseases are found at sites other than synapses, increasing evidence supports the idea that synapses are where the pathogenesis begins. Understanding these diseases is hampered by our lack of knowledge of what the normal functions of these proteins are and how they are affected by aging. Evidence has supported the idea that neurodegenerative disease-linked proteins have a common propensity for prion protein-like cell-to-cell propagation. However, it is not thought that the prion-like quality of these proteins/peptides that allows their cell-to-cell transmission implies a role for human-to-human spread in common age-related neurodegenerative diseases. It will be important to better understand the molecular and cellular mechanisms governing the role of these aggregating proteins in neural function, especially at synapses, how their propagation occurs and how pathogenesis is promoted by aging.
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Yang NY, Lee YN, Lee HJ, Kim YS, Lee SJ. Glucocerebrosidase, a new player changing the old rules in Lewy body diseases. Biol Chem 2013; 394:807-18. [PMID: 23435096 DOI: 10.1515/hsz-2012-0322] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 02/15/2013] [Indexed: 11/15/2022]
Abstract
Mutations in the gene encoding glucocerebrosidase (GBA1) cause Gaucher disease (GD), a lysosomal storage disease with recessive inheritance. Glucocerebrosidase (GCase) is a lysosomal lipid hydrolase that digests glycolipid substrates, such as glucosylceramide and glucosylsphingosine. GBA1 mutations have been implicated in Lewy body diseases (LBDs), such as Parkinson's disease and dementia with Lewy bodies. Parkinsonism occurs more frequently in certain types of GD, and GBA1 mutation carriers are more likely to have LBDs than non-carriers. Furthermore, GCase is often found in Lewy bodies, which are composed of α-synuclein fibrils as well as a variety of proteins and vesicles. In this review, we discuss potential mechanisms of action of GBA1 mutations in LBDs with particular emphasis on α-synuclein aggregation by reviewing the current literature on the role of GCase in lysosomal functions and glycolipid metabolism.
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Affiliation(s)
- Na-Young Yang
- Department of Biomedical Science and Technology , Konkuk University, Seoul 143-701, Korea
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Alpha-synuclein transmission and mitochondrial toxicity in primary human foetal enteric neurons in vitro. Neurotox Res 2013; 25:170-82. [PMID: 24026637 DOI: 10.1007/s12640-013-9420-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 08/06/2013] [Accepted: 08/17/2013] [Indexed: 01/19/2023]
Abstract
Parkinson's disease (PD) is a multicentred neurodegenerative disorder characterised by the accumulation and aggregation of alpha-synuclein (α-syn) in several parts of the central nervous system. However, it is well established that PD can generate symptoms of constipation and other gastrointestinal problems and α-syn containing lesions have been identified in intestinal nerve cells. In this study, we show that α-syn can be taken up and accumulate in primary human foetal enteric neurons from the gastrointestinal tract and can be transferred between foetal enteric neurons. Impaired proteosomal/lysosomal degradation can promote the uptake and accumulation of α-syn in enteric neurons. Enteric neurons exposed to α-syn can also lead to impaired mitochondrial complex I activity, reduced mitochondrial function, and NAD(+) depletion culminating in cell death via energy restriction. These findings demonstrate neuron-to-neuron transmission of α-syn in enteric neurons, providing renewed evidence for Braak's hypothesis and the aetiology of PD.
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Zahran AM, Elsayh KI, El-Deek SEM, El-Baz MAH. Oxidative stress, trace elements, and circulating microparticles in patients with Gaucher disease before and after enzyme replacement therapy. Clin Appl Thromb Hemost 2013; 21:58-65. [PMID: 23698728 DOI: 10.1177/1076029613489595] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
UNLABELLED We studied the level of lipid peroxide, nitric oxide (NO), trace elements (TEs), and microparticles (MPs) in Gaucher disease (GD) before and after 1 year of enzyme replacement therapy (ERT). A total of 15 children with GD and 15 healthy controls were enrolled in this study. Serum level of lipid peroxide, NO, and TEs was determined. The MPs were detected by flow cytometry. The level of lipid peroxide was significantly higher in the patients than in the controls even after ERT. Although NO level was normalized in the patients after ERT, zinc and copper were still lower in the patients after ERT. The percentages of various MPs were significantly higher in the patients than in the controls both before and after ERT. There were positive correlations between chitotriosidase and both lipid peroxide and total MPs. CONCLUSION The GD is associated with alteration in oxidant and antioxidant status and high level of circulating MPs.
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Affiliation(s)
- Asmaa M Zahran
- Department of Oncological Clinical Pathology, Flow Cytometry Lap, South Egypt Cancer Institute, Assiut University, Egypt
| | - Khalid I Elsayh
- Department of Pediatrics, Faculty of Medicine, Assiut University, Egypt
| | - Sahar E M El-Deek
- Department of Medical Biochemistry, Faculty of Medicine, Assiut University, Egypt
| | - Mona A H El-Baz
- Department of Medical Biochemistry, Faculty of Medicine, Assiut University, Egypt
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Brozzi A, Urbanelli L, Germain PL, Magini A, Emiliani C. hLGDB: a database of human lysosomal genes and their regulation. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2013; 2013:bat024. [PMID: 23584836 PMCID: PMC3625959 DOI: 10.1093/database/bat024] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Lysosomes are cytoplasmic organelles present in almost all eukaryotic cells, which play a fundamental role in key aspects of cellular homeostasis such as membrane repair, autophagy, endocitosis and protein metabolism. The characterization of the genes and enzymes constituting the lysosome represents a central issue to be addressed toward a better understanding of the biology of this organelle. In humans, mutations that cause lysosomal enzyme deficiencies result in >50 different disorders and severe pathologies. So far, many experimental efforts using different methodologies have been carried out to identity lysosomal genes. The Human Lysosome Gene Database (hLGDB) is the first resource that provides a comprehensive and accessible census of the human genes belonging to the lysosomal system. This database was developed by collecting and annotating gene lists from many different sources. References to the studies that have identified each gene are provided together with cross databases gene related information. Special attention has been given to the regulation of the genes through microRNAs and the transcription factor EB. The hLGDB can be easily queried to retrieve, combine and analyze information on different lists of lysosomal genes and their regulation by microRNA (binding sites predicted by five different algorithms). The hLGDB is an open access dynamic project that will permit in the future to collapse in a unique publicly accessible resource all the available biological information about lysosome genes and their regulation. Database URL:http://lysosome.unipg.it/
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Affiliation(s)
- Alessandro Brozzi
- Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Via del Giochetto, 06123 Perugia, Italy
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Perez-Gonzalez R, Pascual C, Antequera D, Bolos M, Redondo M, Perez DI, Pérez-Grijalba V, Krzyzanowska A, Sarasa M, Gil C, Ferrer I, Martinez A, Carro E. Phosphodiesterase 7 inhibitor reduced cognitive impairment and pathological hallmarks in a mouse model of Alzheimer's disease. Neurobiol Aging 2013; 34:2133-45. [PMID: 23582662 DOI: 10.1016/j.neurobiolaging.2013.03.011] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 01/10/2013] [Accepted: 03/11/2013] [Indexed: 01/12/2023]
Abstract
Elevated levels of amyloid beta (Aβ) peptide, hyperphosphorylation of tau protein, and inflammation are pathological hallmarks in Alzheimer's disease (AD). Phosphodiesterase 7 (PDE7) regulates the inflammatory response through the cyclic adenosine monophosphate signaling cascade, and thus plays a central role in AD. The aim of this study was to evaluate the efficacy of an inhibitor of PDE7, named S14, in a mouse model of AD. We report that APP/Ps1 mice treated daily for 4 weeks with S14 show: (1) significant attenuation in behavioral impairment; (2) decreased brain Aβ deposition; (3) enhanced astrocyte-mediated Aβ degradation; and (4) decreased tau phosphorylation. These effects are mediated via the cyclic adenosine monophosphate/cyclic adenosine monophosphate response element-binding protein signaling pathway, and inactivation of glycogen synthase kinase (GSK)3. Our data support the use of PDE7 inhibitors, and specifically S14, as effective therapeutic agents for the prevention and treatment of AD.
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Affiliation(s)
- Rocio Perez-Gonzalez
- Neuroscience Group, Instituto de Investigacion Hospital 12 de Octubre (i+12), Madrid, Spain
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41
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Extracellular matrix components: An intricate network of possible biomarkers for lysosomal storage disorders? FEBS Lett 2013; 587:1258-67. [DOI: 10.1016/j.febslet.2013.02.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 02/18/2013] [Accepted: 02/19/2013] [Indexed: 01/13/2023]
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Abstract
PURPOSE OF REVIEW Age-related muscle weakness causes a staggering economic, public, and personal burden. Most research has focused on internal muscular mechanisms as the root cause to strength loss. Here, we briefly discuss age-related impairments in the brain and peripheral nerve structures that may theoretically lead to muscle weakness in old age. RECENT FINDINGS Neuronal atrophy in the brain is accompanied by electrical noise tied to declines in dopaminergic neurotransmission that degrades communication between neurons. Additionally, sensorimotor feedback loops that help regulate corticospinal excitability are impaired. In the periphery, there is evidence for motor unit loss, axonal atrophy, demyelination caused by oxidative damage to proteins and lipids, and modified transmission of the electrical signal through the neuromuscular junction. SUMMARY Recent evidence clearly indicates that muscle weakness associated with aging is not entirely explained by classically postulated atrophy of muscle. In this issue, which focuses on 'Ageing: Biology and Nutrition' we will highlight new findings on how nervous system changes contribute to the aging muscle phenotype. These findings indicate that the ability to communicate neural activity to skeletal muscle is impaired with advancing age, which raises the question of whether many of these age-related neurological changes are mechanistically linked to impaired performance of human skeletal muscle. Collectively, this work suggests that future research should explore the direct link of these 'upstream' neurological adaptions and onset of muscle weakness in elders. In the long term, this new focus might lead to novel strategies to attenuate the age-related loss of muscle strength.
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Affiliation(s)
- Todd M Manini
- Institute of Aging and the Department of Aging and Geriatric Research, University of Florida, Gainesville, Florida 32611, USA.
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Viswanathan K, Hoover DJ, Hwang J, Wisniewski ML, Ikonne US, Bahr BA, Wright DL. Nonpeptidic lysosomal modulators derived from z-phe-ala-diazomethylketone for treating protein accumulation diseases. ACS Med Chem Lett 2012; 3:920-4. [PMID: 24900408 DOI: 10.1021/ml300197h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 09/09/2012] [Indexed: 11/29/2022] Open
Abstract
Lysosomes are involved in protein turnover and removing misfolded species, and their enzymes have the potential to offset the defect in proteolytic clearance that contributes to the age-related dementia Alzheimer's disease (AD). The weak cathepsin B and L inhibitor Z-Phe-Ala-diazomethylketone (PADK) enhances lysosomal cathepsin levels at low concentrations, thereby eliciting protective clearance of PHF-τ and Aβ42 in the hippocampus and other brain regions. Here, a class of positive modulators is established with compounds decoupled from the cathepsin inhibitory properties. We utilized PADK as a departure point to develop nonpeptidic structures with the hydroxyethyl isostere. The first-in-class modulators SD1002 and SD1003 exhibit improved levels of cathepsin up-regulation but almost complete removal of cathepsin inhibitory properties as compared to PADK. Isomers of the lead compound SD1002 were synthesized, and the modulatory activity was determined to be stereoselective. In addition, the lead compound was tested in transgenic mice with results indicating protection against AD-type protein accumulation pathology.
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Affiliation(s)
- Kishore Viswanathan
- Department of Pharmaceutical
Sciences, University of Connecticut, Storrs,
Connecticut 06269, United States
| | - Dennis J. Hoover
- Synaptic Dynamics Inc., Farmington, Connecticut 06032, United States
| | - Jeannie Hwang
- Department of Pharmaceutical
Sciences, University of Connecticut, Storrs,
Connecticut 06269, United States
- William C. Friday Laboratory,
Biotechnology Research and Training Center, University of North Carolina—Pembroke, Pembroke, North Carolina
28372, United States
| | - Meagan L. Wisniewski
- William C. Friday Laboratory,
Biotechnology Research and Training Center, University of North Carolina—Pembroke, Pembroke, North Carolina
28372, United States
| | - Uzoma S. Ikonne
- William C. Friday Laboratory,
Biotechnology Research and Training Center, University of North Carolina—Pembroke, Pembroke, North Carolina
28372, United States
| | - Ben A. Bahr
- Department of Pharmaceutical
Sciences, University of Connecticut, Storrs,
Connecticut 06269, United States
- William C. Friday Laboratory,
Biotechnology Research and Training Center, University of North Carolina—Pembroke, Pembroke, North Carolina
28372, United States
| | - Dennis L. Wright
- Department of Pharmaceutical
Sciences, University of Connecticut, Storrs,
Connecticut 06269, United States
- Synaptic Dynamics Inc., Farmington, Connecticut 06032, United States
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Kurashige T, Takahashi T, Yamazaki Y, Hiji M, Izumi Y, Yamawaki T, Matsumoto M. Localization of CHMP2B-immunoreactivity in the brainstem of Lewy body disease. Neuropathology 2012; 33:237-45. [PMID: 22989140 DOI: 10.1111/j.1440-1789.2012.01346.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Revised: 08/11/2012] [Accepted: 08/12/2012] [Indexed: 12/21/2022]
Abstract
Alpha-synuclein (αS) is one of the major constituents of Lewy bodies (LBs). Several lines of evidence suggest that the autophagy-lysosome pathway (ALP) is involved in the removal of αS. We have previously reported that granulovacuolar degeneration (GVD) in neurons involved a subunit of the endosomal sorting complexes required for transport (ESCRT). In this study, we examined the association between alpha-synucleinopathy and autophagy through immunohistochemical analysis of charged multivesicular body protein 2B (CHMP2B), a component of the ESCRT-pathway. We examined the brainstems of 17 patients with Parkinson's disease (PD), incidental Lewy body disease (ILBD), multiple system atrophy (MSA), and Alzheimer's disease (AD) immunohistochemically using antibodies against phosphorylated αS (pαS), phosphorylated tau and CHMP2B. LBs and a proportion of glial cytoplasmic inclusions (GCIs) were immunopositive for pαS and CHMP2B. Neurons containing CHMP2B-immunoreactive granules were detected in PD and ILBD, but not in MSA and AD brains. CHMP2B immunoreactivity was increased in the dorsal motor nucleus of the vagus nerve (DMNX) in PD and ILBD brains, relative to that in MSA and AD. These findings indicate that the ESCRT-pathway is implicated in the formation of αS inclusions, especially in PD and ILBD.
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Affiliation(s)
- Takashi Kurashige
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
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Bahr BA, Wisniewski ML, Butler D. Positive lysosomal modulation as a unique strategy to treat age-related protein accumulation diseases. Rejuvenation Res 2012; 15:189-97. [PMID: 22533430 DOI: 10.1089/rej.2011.1282] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Lysosomes are involved in degrading and recycling cellular ingredients, and their disruption with age may contribute to amyloidogenesis, paired helical filaments (PHFs), and α-synuclein and mutant huntingtin aggregation. Lysosomal cathepsins are upregulated by accumulating proteins and more so by the modulator Z-Phe-Ala-diazomethylketone (PADK). Such positive modulators of the lysosomal system have been studied in the well-characterized hippocampal slice model of protein accumulation that exhibits the pathogenic cascade of tau aggregation, tubulin breakdown, microtubule destabilization, transport failure, and synaptic decline. Active cathepsins were upregulated by PADK; Rab proteins were modified as well, indicating enhanced trafficking, whereas lysosome-associated membrane protein and proteasome markers were unchanged. Lysosomal modulation reduced the pre-existing PHF deposits, restored tubulin structure and transport, and recovered synaptic components. Further proof-of-principle studies used Alzheimer disease mouse models. It was recently reported that systemic PADK administration caused dramatic increases in cathepsin B protein and activity levels, whereas neprilysin, insulin-degrading enzyme, α-secretase, and β-secretase were unaffected by PADK. In the transgenic models, PADK treatment resulted in clearance of intracellular amyloid beta (Aβ) peptide and concomitant reduction of extracellular deposits. Production of the less pathogenic Aβ(1-38) peptide corresponded with decreased levels of Aβ(1-42), supporting the lysosome's antiamyloidogenic role through intracellular truncation. Amelioration of synaptic and behavioral deficits also indicates a neuroprotective function of the lysosomal system, identifying lysosomal modulation as an avenue for disease-modifying therapies. From the in vitro and in vivo findings, unique lysosomal modulators represent a minimally invasive, pharmacologically controlled strategy against protein accumulation disorders to enhance protein clearance, promote synaptic integrity, and slow the progression of dementia.
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Affiliation(s)
- Ben A Bahr
- William C. Friday Laboratory, Biotechnology Research and Training Center, University of North Carolina Pembroke, Pembroke, North Carolina 28372-1510, USA.
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Abstract
Dementias are a varied group of disorders typically associated with memory loss, impaired judgment and/or language and by symptoms affecting other cognitive and social abilities to a degree that interferes with daily functioning. Alzheimer's disease (AD) is the most common cause of a progressive dementia, followed by dementia with Lewy bodies (DLB), frontotemporal dementia (FTD), (VaD) and HIV-associated neurocognitive disorders (HAND). The pathogenesis of this group of disorders has been linked to the abnormal accumulation of proteins in the brains of affected individuals, which in turn has been related to deficits in protein clearance. Autophagy is a key cellular protein clearance pathway with proteolytic cleavage and degradation via the ubiquitin-proteasome pathway representing another important clearance mechanism. Alterations in the levels of autophagy and the proteins associated with the autophagocytic pathway have been reported in various types of dementias. This review will examine recent literature across these disorders and highlight a common theme of altered autophagy across the spectrum of the dementias.
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Ihara Y, Morishima-Kawashima M, Nixon R. The ubiquitin-proteasome system and the autophagic-lysosomal system in Alzheimer disease. Cold Spring Harb Perspect Med 2012; 2:a006361. [PMID: 22908190 PMCID: PMC3405832 DOI: 10.1101/cshperspect.a006361] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
As neurons age, their survival depends on eliminating a growing burden of damaged, potentially toxic proteins and organelles-a capability that declines owing to aging and disease factors. Here, we review the two proteolytic systems principally responsible for protein quality control in neurons and their important contributions to Alzheimer disease pathogenesis. In the first section, the discovery of paired helical filament ubiquitination is described as a backdrop for discussing the importance of the ubiquitin-proteasome system in Alzheimer disease. In the second section, we review the prominent involvement of the lysosomal system beginning with pathological endosomal-lysosomal activation and signaling at the very earliest stages of Alzheimer disease followed by the progressive failure of autophagy. These abnormalities, which result in part from Alzheimer-related genes acting directly on these lysosomal pathways, contribute to the development of each of the Alzheimer neuropathological hallmarks and represent a promising therapeutic target.
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Affiliation(s)
- Yasuo Ihara
- Department of Neuropathology, Faculty of Life and Medical Science, Doshisha University, Kyoto, Japan.
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Lysosomal dysfunction in a mouse model of Sandhoff disease leads to accumulation of ganglioside-bound amyloid-β peptide. J Neurosci 2012; 32:5223-36. [PMID: 22496568 DOI: 10.1523/jneurosci.4860-11.2012] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Alterations in the lipid composition of endosomal-lysosomal membranes may constitute an early event in Alzheimer's disease (AD) pathogenesis. In this study, we investigated the possibility that GM2 ganglioside accumulation in a mouse model of Sandhoff disease might be associated with the accumulation of intraneuronal and extracellular proteins commonly observed in AD. Our results show intraneuronal accumulation of amyloid-β peptide (Aβ)-like, α-synuclein-like, and phospho-tau-like immunoreactivity in the brains of β-hexosaminidase knock-out (HEXB KO) mice. Biochemical and immunohistochemical analyses confirmed that at least some of the intraneuronal Aβ-like immunoreactivity (iAβ-LIR) represents amyloid precursor protein C-terminal fragments (APP-CTFs) and/or Aβ. In addition, we observed increased levels of Aβ40 and Aβ42 peptides in the lipid-associated fraction of HEXB KO mouse brains, and intraneuronal accumulation of ganglioside-bound Aβ (GAβ) immunoreactivity in a brain region-specific manner. Furthermore, α-synuclein and APP-CTFs and/or Aβ were found to accumulate in different regions of the substantia nigra, indicating different mechanisms of accumulation or turnover pathways. Based on the localization of the accumulated iAβ-LIR to endosomes, lysosomes, and autophagosomes, we conclude that a significant accumulation of iAβ-LIR may be associated with the lysosomal-autophagic turnover of Aβ and fragments of APP-containing Aβ epitopes. Importantly, intraneuronal GAβ immunoreactivity, a proposed prefibrillar aggregate found in AD, was found to accumulate throughout the frontal cortices of postmortem human GM1 gangliosidosis, Sandhoff disease, and Tay-Sachs disease brains. Together, these results establish an association between the accumulation of gangliosides, autophagic vacuoles, and the intraneuronal accumulation of proteins associated with AD.
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Endolysosome involvement in LDL cholesterol-induced Alzheimer's disease-like pathology in primary cultured neurons. Life Sci 2012; 91:1159-68. [PMID: 22580286 DOI: 10.1016/j.lfs.2012.04.039] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 04/19/2012] [Accepted: 04/24/2012] [Indexed: 12/26/2022]
Abstract
AIMS Elevated levels of circulating cholesterol are extrinsic factors contributing to the pathogenesis of sporadic Alzheimer's disease (AD). We showed previously that rabbits fed a cholesterol-enriched diet exhibited blood-brain barrier (BBB) dysfunction, increased accumulation of apolipoprotein B (ApoB) in brain neurons, and endolysosomes in brain had disturbed structures and functions. These effects were linked to increased amyloid beta (Aβ) production, increased tau-pathology, and disrupted synaptic integrity. Because pathological changes to endolysosomes represent a very early event in sporadic AD, we determined here the extent to which ApoB-containing LDL cholesterol altered the structure and function of endolysosomes and contributed to the development of AD-like pathology in primary cultured neurons. MAIN METHODS Cholesterol distribution and endolysosome morphology were determined histologically. Endolysosome pH was measured ratio-metrically with LysoSensor dye. Endolysosome enzyme activity was measured for acid phosphatase, cathepsins B and D, and beta-site APP cleaving enzyme 1 (BACE-1). AD-like pathologies, including increased production of Aβ, increased tau-pathology, and disrupted synaptic integrity were determined using ELISA, immunoblotting, and immunostaining techniques. KEY FINDINGS Treatment of neurons with ApoB-containing LDL cholesterol increased endolysosome accumulation of cholesterol, enlarged endolysosomes, and elevated endolysosome pH. In addition, ApoB-containing LDL cholesterol increased endolysosome accumulation of BACE-1, enhanced BACE-1 activity, increased Aβ levels, increased levels of phosphorylated tau, and decreased levels of synaptophysin. SIGNIFICANCE Our findings suggest strongly that alterations in the structure and function of endolysosomes play a key role in the exhibition of pathological features of AD that result from neuronal exposure to ApoB-containing LDL cholesterol.
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50
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Lang CM, Fellerer K, Schwenk BM, Kuhn PH, Kremmer E, Edbauer D, Capell A, Haass C. Membrane orientation and subcellular localization of transmembrane protein 106B (TMEM106B), a major risk factor for frontotemporal lobar degeneration. J Biol Chem 2012; 287:19355-65. [PMID: 22511793 DOI: 10.1074/jbc.m112.365098] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
TMEM106B was identified as a major risk factor in a genome-wide association study for frontotemporal lobar degeneration (FTLD) with TAR DNA-binding protein (TDP)-43 pathology. The most significant association of TMEM106B single nucleotide polymorphisms with risk of FTLD-TDP was observed in patients with progranulin (GRN) mutations. Subsequent studies suggested an inverse correlation between TMEM106B expression and GRN levels in patient serum. However, in this study, this was not confirmed as we failed to detect a significant alteration of GRN levels upon knockdown or exogenous expression of TMEM106B in heterologous cells. To provide a basis for understanding TMEM106B function in health and disease, we investigated the membrane orientation and subcellular localization of this completely uncharacterized protein. By differential membrane extraction and sequential mutagenesis of potential N-glycosylation sites, we identified TMEM106B as a type 2 integral membrane protein with a highly glycosylated luminal domain. Glycosylation is partially required for the transport of TMEM106B beyond the endoplasmic reticulum to late cellular compartments. Endogenous as well as overexpressed TMEM106B localizes to late endosomes and lysosomes. Interestingly, the inhibition of vacuolar H(+)-ATPases significantly increased the levels of TMEM106B, a finding that may provide an unexpected biochemical link to GRN, because this protein is also strongly increased under the same conditions. Our findings provide a biochemical and cell biological basis for the understanding of the pathological role of TMEM106B in FTLD, an incurable neurodegenerative disorder.
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Affiliation(s)
- Christina M Lang
- Adolf-Butenandt-Institute, Biochemistry, Ludwig-Maximilians-University, 80336 Munich, Germany.
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