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Lee CH, Murrell CE, Chu A, Pan X. Circadian Regulation of Apolipoproteins in the Brain: Implications in Lipid Metabolism and Disease. Int J Mol Sci 2023; 24:17415. [PMID: 38139244 PMCID: PMC10743770 DOI: 10.3390/ijms242417415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/08/2023] [Accepted: 12/10/2023] [Indexed: 12/24/2023] Open
Abstract
The circadian rhythm is a 24 h internal clock within the body that regulates various factors, including sleep, body temperature, and hormone secretion. Circadian rhythm disruption is an important risk factor for many diseases including neurodegenerative illnesses. The central and peripheral oscillators' circadian clock network controls the circadian rhythm in mammals. The clock genes govern the central clock in the suprachiasmatic nucleus (SCN) of the brain. One function of the circadian clock is regulating lipid metabolism. However, investigations of the circadian regulation of lipid metabolism-associated apolipoprotein genes in the brain are lacking. This review summarizes the rhythmic expression of clock genes and lipid metabolism-associated apolipoprotein genes within the SCN in Mus musculus. Nine of the twenty apolipoprotein genes identified from searching the published database (SCNseq and CircaDB) are highly expressed in the SCN. Most apolipoprotein genes (ApoE, ApoC1, apoA1, ApoH, ApoM, and Cln) show rhythmic expression in the brain in mice and thus might be regulated by the master clock. Therefore, this review summarizes studies on lipid-associated apolipoprotein genes in the SCN and other brain locations, to understand how apolipoproteins associated with perturbed cerebral lipid metabolism cause multiple brain diseases and disorders. This review describes recent advancements in research, explores current questions, and identifies directions for future research.
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Affiliation(s)
- Chaeeun Hannah Lee
- Department of Foundations of Medicine, New York University Grossman Long Island School of Medicine, Mineola, NY 11501, USA
| | - Charlotte Ellzabeth Murrell
- Department of Foundations of Medicine, New York University Grossman Long Island School of Medicine, Mineola, NY 11501, USA
| | - Alexander Chu
- Department of Foundations of Medicine, New York University Grossman Long Island School of Medicine, Mineola, NY 11501, USA
| | - Xiaoyue Pan
- Department of Foundations of Medicine, New York University Grossman Long Island School of Medicine, Mineola, NY 11501, USA
- Diabetes and Obesity Research Center, NYU Langone Hospital-Long Island, Mineola, NY 11501, USA
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2
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Wilson MR, Satapathy S, Vendruscolo M. Extracellular protein homeostasis in neurodegenerative diseases. Nat Rev Neurol 2023; 19:235-245. [PMID: 36828943 DOI: 10.1038/s41582-023-00786-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/02/2023] [Indexed: 02/26/2023]
Abstract
The protein homeostasis (proteostasis) system encompasses the cellular processes that regulate protein synthesis, folding, concentration, trafficking and degradation. In the case of intracellular proteostasis, the identity and nature of these processes have been extensively studied and are relatively well known. By contrast, the mechanisms of extracellular proteostasis are yet to be fully elucidated, although evidence is accumulating that their age-related progressive impairment might contribute to neuronal death in neurodegenerative diseases. Constitutively secreted extracellular chaperones are emerging as key players in processes that operate to protect neurons and other brain cells by neutralizing the toxicity of extracellular protein aggregates and promoting their safe clearance and disposal. Growing evidence indicates that these extracellular chaperones exert multiple effects to promote cell viability and protect neurons against pathologies arising from the misfolding and aggregation of proteins in the synaptic space and interstitial fluid. In this Review, we outline the current knowledge of the mechanisms of extracellular proteostasis linked to neurodegenerative diseases, and we examine the latest understanding of key molecules and processes that protect the brain from the pathological consequences of extracellular protein aggregation and proteotoxicity. Finally, we contemplate possible therapeutic opportunities for neurodegenerative diseases on the basis of this emerging knowledge.
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Affiliation(s)
- Mark R Wilson
- School of Chemistry and Molecular Bioscience, Molecular Horizons Research Institute, University of Wollongong, Wollongong, New South Wales, Australia.
| | - Sandeep Satapathy
- Blavatnik Institute of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Michele Vendruscolo
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
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3
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Braun JE. Extracellular chaperone networks and the export of J-domain proteins. J Biol Chem 2022; 299:102840. [PMID: 36581212 PMCID: PMC9867986 DOI: 10.1016/j.jbc.2022.102840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 12/18/2022] [Accepted: 12/20/2022] [Indexed: 12/27/2022] Open
Abstract
An extracellular network of molecular chaperones protects a diverse array of proteins that reside in or pass through extracellular spaces. Proteins in the extracellular milieu face numerous challenges that can lead to protein misfolding and aggregation. As a checkpoint for proteins that move between cells, extracellular chaperone networks are of growing clinical relevance. J-domain proteins (JDPs) are ubiquitous molecular chaperones that are known for their essential roles in a wide array of fundamental cellular processes through their regulation of heat shock protein 70s. As the largest molecular chaperone family, JDPs have long been recognized for their diverse functions within cells. Some JDPs are elegantly selective for their "client proteins," some do not discriminate among substrates and others act cooperatively on the same target. The realization that JDPs are exported through both classical and unconventional secretory pathways has fueled investigation into the roles that JDPs play in protein quality control and intercellular communication. The proposed functions of exported JDPs are diverse. Studies suggest that export of DnaJB11 enhances extracellular proteostasis, that intercellular movement of DnaJB1 or DnaJB6 enhances the proteostasis capacity in recipient cells, whereas the import of DnaJB8 increases resistance to chemotherapy in recipient cancer cells. In addition, the export of DnaJC5 and concurrent DnaJC5-dependent ejection of dysfunctional and aggregation-prone proteins are implicated in the prevention of neurodegeneration. This review provides a brief overview of the current understanding of the extracellular chaperone networks and outlines the first wave of studies describing the cellular export of JDPs.
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Sundaria N, Upadhyay A, Prasad A, Prajapati VK, Poluri KM, Mishra A. Neurodegeneration & imperfect ageing: Technological limitations and challenges? Mech Ageing Dev 2021; 200:111574. [PMID: 34562507 DOI: 10.1016/j.mad.2021.111574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 08/29/2021] [Accepted: 09/21/2021] [Indexed: 11/18/2022]
Abstract
Cellular homeostasis is regulated by the protein quality control (PQC) machinery, comprising multiple chaperones and enzymes. Studies suggest that the loss of the PQC mechanisms in neurons may lead to the formation of abnormal inclusions that may lead to neurological disorders and defective aging. The questions could be raised how protein aggregate formation precisely engenders multifactorial molecular pathomechanism in neuronal cells and affects different brain regions? Such questions await thorough investigation that may help us understand how aberrant proteinaceous bodies lead to neurodegeneration and imperfect aging. However, these studies face multiple technological challenges in utilizing available tools for detailed characterizations of the protein aggregates or amyloids and developing new techniques to understand the biology and pathology of proteopathies. The lack of detection and analysis methods has decelerated the pace of the research in amyloid biology. Here, we address the significance of aggregation and inclusion formation, followed by exploring the evolutionary contribution of these structures. We also provide a detailed overview of current state-of-the-art techniques and advances in studying amyloids in the diseased brain. A comprehensive understanding of the structural, pathological, and clinical characteristics of different types of aggregates (inclusions, fibrils, plaques, etc.) will aid in developing future therapies.
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Affiliation(s)
- Naveen Sundaria
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology, Jodhpur, Rajasthan, 342037, India
| | - Arun Upadhyay
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology, Jodhpur, Rajasthan, 342037, India
| | - Amit Prasad
- School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, India
| | - Vijay Kumar Prajapati
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, NH‑8 Bandarsindri, Ajmer, Rajasthan, 305817, India
| | - Krishna Mohan Poluri
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand, India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology, Jodhpur, Rajasthan, 342037, India.
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5
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Tahir U, Hussam A, Roy P, Hashmi I. Noncovalent Association and Partitioning of Some Perfume Components at Infinite Dilution with Myelin Basic Protein Pseudophase in Normal Saline. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:4793-4801. [PMID: 33851853 DOI: 10.1021/acs.langmuir.0c03475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Myelin basic protein (MBP), one of the major protein constituents of the myelin sheath, possesses unique ligand-binding features. We present a novel equilibrium headspace gas chromatographic technique to examine the thermodynamics of noncovalent interactions between common perfume components: Lilial, Hedione, Hexylcinnamic aldehyde, and Versalide with MBP monomers and its hexameric MBP-pseudophase. A general theoretical model is used to calculate the critical aggregation concentration (cac) of MBP, perfume component binding constants with monomeric MBP, K11, and MBP as pseudophase, Kn1, and free energies for perfume component binding with monomeric MBP, ΔGb,11, and MBP as pseudophase, ΔGb,n1. In addition, the pseudophase-water partition coefficients, Kx, the free energies of transfer of perfume from bulk water to the MBP-pseudophase, ΔGt, and the intra-aggregate activity coefficients, γm∞, at infinite dilution were also determined. The cac value measured by the method of fractional distribution is a unique and precise approach in understanding the aggregation phenomenon. Within the experimental error, the 1:1 binding free energies did not differ by more than 1 kJ/mol among the perfume components but favored the MBP pseudophase binding by 6 kJ/mol. Therefore, that protein aggregation can enhance the binding of small molecules is probably a general conclusion. While the magnitudes of K11, Kn1, ΔGb, Kx, and ΔGt show weak trends, the γm∞ values show a strong and distinct trend in interaction, spanning 4 orders of magnitude among the perfume components.
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Affiliation(s)
| | | | | | - Irina Hashmi
- Department of Information Science and Technology, George Mason University, Fairfax, Virginia 22030, United States
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Satapathy S, Wilson MR. The Dual Roles of Clusterin in Extracellular and Intracellular Proteostasis. Trends Biochem Sci 2021; 46:652-660. [PMID: 33573881 DOI: 10.1016/j.tibs.2021.01.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/04/2021] [Accepted: 01/19/2021] [Indexed: 02/06/2023]
Abstract
Clusterin (CLU) was the first reported secreted mammalian chaperone and impacts on serious diseases associated with inappropriate extracellular protein aggregation. Many studies have described intracellular CLU in locations outside the secretory system and recent work has shown that CLU can be released into the cytosol during cell stress. In this article, we critically evaluate evidence relevant to the proposed origins of cellular CLU found outside the secretory system, and advance the hypothesis that the cytosolic release of CLU induced by stress serves to facilitate the trafficking of misfolded proteins to the proteasome and autophagy for degradation. We also propose future research directions that could help establish CLU as a unique chaperone performing critical and synergic roles in both intracellular and extracellular proteostasis.
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Affiliation(s)
- Sandeep Satapathy
- School of Chemistry and Molecular Biosciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia; Molecular Horizons Research Institute, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia; Illawarra Health and Medical Research Institute, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia
| | - Mark R Wilson
- School of Chemistry and Molecular Biosciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia; Molecular Horizons Research Institute, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia; Illawarra Health and Medical Research Institute, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
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Jankovska N, Olejar T, Matej R. Extracellular Amyloid Deposits in Alzheimer's and Creutzfeldt-Jakob Disease: Similar Behavior of Different Proteins? Int J Mol Sci 2020; 22:E7. [PMID: 33374972 PMCID: PMC7792617 DOI: 10.3390/ijms22010007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/18/2020] [Accepted: 12/18/2020] [Indexed: 02/07/2023] Open
Abstract
Neurodegenerative diseases are characterized by the deposition of specific protein aggregates, both intracellularly and/or extracellularly, depending on the type of disease. The extracellular occurrence of tridimensional structures formed by amyloidogenic proteins defines Alzheimer's disease, in which plaques are composed of amyloid β-protein, while in prionoses, the same term "amyloid" refers to the amyloid prion protein. In this review, we focused on providing a detailed didactic description and differentiation of diffuse, neuritic, and burnt-out plaques found in Alzheimer's disease and kuru-like, florid, multicentric, and neuritic plaques in human transmissible spongiform encephalopathies, followed by a systematic classification of the morphological similarities and differences between the extracellular amyloid deposits in these disorders. Both conditions are accompanied by the extracellular deposits that share certain signs, including neuritic degeneration, suggesting a particular role for amyloid protein toxicity.
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Affiliation(s)
- Nikol Jankovska
- Department of Pathology and Molecular Medicine, Third Faculty of Medicine, Charles University and Thomayer Hospital, 100 00 Prague, Czech Republic; (T.O.); (R.M.)
| | - Tomas Olejar
- Department of Pathology and Molecular Medicine, Third Faculty of Medicine, Charles University and Thomayer Hospital, 100 00 Prague, Czech Republic; (T.O.); (R.M.)
| | - Radoslav Matej
- Department of Pathology and Molecular Medicine, Third Faculty of Medicine, Charles University and Thomayer Hospital, 100 00 Prague, Czech Republic; (T.O.); (R.M.)
- Department of Pathology, First Faculty of Medicine, Charles University, and General University Hospital, 100 00 Prague, Czech Republic
- Department of Pathology, Third Faculty of Medicine, Charles University, and University Hospital Kralovske Vinohrady, 100 00 Prague, Czech Republic
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Chaplot K, Jarvela TS, Lindberg I. Secreted Chaperones in Neurodegeneration. Front Aging Neurosci 2020; 12:268. [PMID: 33192447 PMCID: PMC7481362 DOI: 10.3389/fnagi.2020.00268] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/03/2020] [Indexed: 12/11/2022] Open
Abstract
Protein homeostasis, or proteostasis, is a combination of cellular processes that govern protein quality control, namely, protein translation, folding, processing, and degradation. Disruptions in these processes can lead to protein misfolding and aggregation. Proteostatic disruption can lead to cellular changes such as endoplasmic reticulum or oxidative stress; organelle dysfunction; and, if continued, to cell death. A majority of neurodegenerative diseases involve the pathologic aggregation of proteins that subverts normal neuronal function. While prior reviews of neuronal proteostasis in neurodegenerative processes have focused on cytoplasmic chaperones, there is increasing evidence that chaperones secreted both by neurons and other brain cells in the extracellular - including transsynaptic - space play important roles in neuronal proteostasis. In this review, we will introduce various secreted chaperones involved in neurodegeneration. We begin with clusterin and discuss its identification in various protein aggregates, and the use of increased cerebrospinal fluid (CSF) clusterin as a potential biomarker and as a potential therapeutic. Our next secreted chaperone is progranulin; polymorphisms in this gene represent a known genetic risk factor for frontotemporal lobar degeneration, and progranulin overexpression has been found to be effective in reducing Alzheimer's- and Parkinson's-like neurodegenerative phenotypes in mouse models. We move on to BRICHOS domain-containing proteins, a family of proteins containing highly potent anti-amyloidogenic activity; we summarize studies describing the biochemical mechanisms by which recombinant BRICHOS protein might serve as a therapeutic agent. The next section of the review is devoted to the secreted chaperones 7B2 and proSAAS, small neuronal proteins which are packaged together with neuropeptides and released during synaptic activity. Since proteins can be secreted by both classical secretory and non-classical mechanisms, we also review the small heat shock proteins (sHsps) that can be secreted from the cytoplasm to the extracellular environment and provide evidence for their involvement in extracellular proteostasis and neuroprotection. Our goal in this review focusing on extracellular chaperones in neurodegenerative disease is to summarize the most recent literature relating to neurodegeneration for each secreted chaperone; to identify any common mechanisms; and to point out areas of similarity as well as differences between the secreted chaperones identified to date.
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Affiliation(s)
| | | | - Iris Lindberg
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, University of Maryland, Baltimore, Baltimore, MD, United States
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9
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α-synuclein-lipoprotein interactions and elevated ApoE level in cerebrospinal fluid from Parkinson's disease patients. Proc Natl Acad Sci U S A 2019; 116:15226-15235. [PMID: 31270237 PMCID: PMC6660770 DOI: 10.1073/pnas.1821409116] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Two of the most important issues in Parkinson’s disease (PD) research are the identification of mechanisms underlying α-synuclein cell-to-cell transfer in the nervous system and the discovery of early diagnostic biomarkers. Both of these issues are addressed in our current manuscript. Using multiple approaches, we present that α-synuclein interacts with lipoproteins within human cerebrospinal fluid and can be taken up by cells in such a state. Moreover, using cerebrospinal fluid samples from 3 large and independent cohorts of patients, we demonstrate that apolipoprotein E is elevated in early, not yet medicated, patients with PD. Finally, using postmortem brain tissue, we provide preliminary histological evidence that apolipoprotein E is enriched in a subpopulation of dopaminergic neurons of human substantia nigra. The progressive accumulation, aggregation, and spread of α-synuclein (αSN) are common hallmarks of Parkinson’s disease (PD) pathology. Moreover, numerous proteins interact with αSN species, influencing its toxicity in the brain. In the present study, we extended analyses of αSN-interacting proteins to cerebrospinal fluid (CSF). Using coimmunoprecipitation, followed by mass spectrometry, we found that αSN colocalize with apolipoproteins on lipoprotein vesicles. We confirmed these interactions using several methods, including the enrichment of lipoproteins with a recombinant αSN, and the subsequent uptake of prepared vesicles by human dopaminergic neuronal-like cells. Further, we report an increased level of ApoE in CSF from early PD patients compared with matched controls in 3 independent cohorts. Moreover, in contrast to controls, we observed the presence of ApoE-positive neuromelanin-containing dopaminergic neurons in substantia nigra of PD patients. In conclusion, the cooccurrence of αSN on lipoprotein vesicles, and their uptake by dopaminergic neurons along with an increase of ApoE in early PD, proposes a mechanism(s) for αSN spreading in the extracellular milieu of PD.
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Sharma S, Young RJ, Chen J, Chen X, Oh EC, Schiller MR. Minimotifs dysfunction is pervasive in neurodegenerative disorders. ALZHEIMER'S & DEMENTIA (NEW YORK, N. Y.) 2018; 4:414-432. [PMID: 30225339 PMCID: PMC6139474 DOI: 10.1016/j.trci.2018.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Minimotifs are modular contiguous peptide sequences in proteins that are important for posttranslational modifications, binding to other molecules, and trafficking to specific subcellular compartments. Some molecular functions of proteins in cellular pathways can be predicted from minimotif consensus sequences identified through experimentation. While a role for minimotifs in regulating signal transduction and gene regulation during disease pathogenesis (such as infectious diseases and cancer) is established, the therapeutic use of minimotif mimetic drugs is limited. In this review, we discuss a general theme identifying a pervasive role of minimotifs in the pathomechanism of neurodegenerative diseases. Beyond their longstanding history in the genetics of familial neurodegeneration, minimotifs are also major players in neurotoxic protein aggregation, aberrant protein trafficking, and epigenetic regulation. Generalizing the importance of minimotifs in neurodegenerative diseases offers a new perspective for the future study of neurodegenerative mechanisms and the investigation of new therapeutics.
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Affiliation(s)
- Surbhi Sharma
- Nevada Institute of Personalized Medicine, Las Vegas, NV, USA
- School of Life Sciences, Las Vegas, NV, USA
| | - Richard J. Young
- Nevada Institute of Personalized Medicine, Las Vegas, NV, USA
- School of Life Sciences, Las Vegas, NV, USA
| | - Jingchun Chen
- Nevada Institute of Personalized Medicine, Las Vegas, NV, USA
| | - Xiangning Chen
- Nevada Institute of Personalized Medicine, Las Vegas, NV, USA
- Department of Psychology, Las Vegas, NV, USA
| | - Edwin C. Oh
- Nevada Institute of Personalized Medicine, Las Vegas, NV, USA
- School of Medicine, Las Vegas, NV, USA
| | - Martin R. Schiller
- Nevada Institute of Personalized Medicine, Las Vegas, NV, USA
- School of Life Sciences, Las Vegas, NV, USA
- School of Medicine, Las Vegas, NV, USA
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Ferrer I. Sisyphus in Neverland. J Alzheimers Dis 2018; 62:1023-1047. [PMID: 29154280 PMCID: PMC5870014 DOI: 10.3233/jad-170609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2017] [Indexed: 11/24/2022]
Abstract
The study of life and living organisms and the way in which these interact and organize to form social communities have been central to my career. I have been fascinated by biology, neurology, and neuropathology, but also by history, sociology, and art. Certain current historical, political, and social events, some occurring proximally but others affecting people in apparently distant places, have had an impact on me. Epicurus, Seneca, and Camus shared their philosophical positions which I learned from. Many scientists from various disciplines have been exciting sources of knowledge as well. I have created a world of hypothesis and experiments but I have also got carried away by serendipity following unexpected observations. It has not been an easy path; errors and wanderings are not uncommon, and opponents close to home much more abundant than one might imagine. Ambition, imagination, resilience, and endurance have been useful in moving ahead in response to setbacks. In the end, I have enjoyed my dedication to science and I am grateful to have glimpsed beauty in it. These are brief memories of a Spanish neuropathologist born and raised in Barcelona, EU.
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Affiliation(s)
- Isidro Ferrer
- Department of Pathology and Experimental Therapeutics, University of Barcelona; Service of Pathological Anatomy, Bellvitge University Hospital; CIBERNED; Hospitalet de Llobregat, Barcelona, Spain
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12
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Ferrer I. Diversity of astroglial responses across human neurodegenerative disorders and brain aging. Brain Pathol 2017; 27:645-674. [PMID: 28804999 PMCID: PMC8029391 DOI: 10.1111/bpa.12538] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 05/24/2017] [Indexed: 12/11/2022] Open
Abstract
Astrogliopathy refers to alterations of astrocytes occurring in diseases of the nervous system, and it implies the involvement of astrocytes as key elements in the pathogenesis and pathology of diseases and injuries of the central nervous system. Reactive astrocytosis refers to the response of astrocytes to different insults to the nervous system, whereas astrocytopathy indicates hypertrophy, atrophy/degeneration and loss of function and pathological remodeling occurring as a primary cause of a disease or as a factor contributing to the development and progression of a particular disease. Reactive astrocytosis secondary to neuron loss and astrocytopathy due to intrinsic alterations of astrocytes occur in neurodegenerative diseases, overlap each other, and, together with astrocyte senescence, contribute to disease-specific astrogliopathy in aging and neurodegenerative diseases with abnormal protein aggregates in old age. In addition to the well-known increase in glial fibrillary acidic protein and other proteins in reactive astrocytes, astrocytopathy is evidenced by deposition of abnormal proteins such as β-amyloid, hyper-phosphorylated tau, abnormal α-synuclein, mutated huntingtin, phosphorylated TDP-43 and mutated SOD1, and PrPres , in Alzheimer's disease, tauopathies, Lewy body diseases, Huntington's disease, amyotrophic lateral sclerosis and Creutzfeldt-Jakob disease, respectively. Astrocytopathy in these diseases can also be manifested by impaired glutamate transport; abnormal metabolism and release of neurotransmitters; altered potassium, calcium and water channels resulting in abnormal ion and water homeostasis; abnormal glucose metabolism; abnormal lipid and, particularly, cholesterol metabolism; increased oxidative damage and altered oxidative stress responses; increased production of cytokines and mediators of the inflammatory response; altered expression of connexins with deterioration of cell-to-cell networks and transfer of gliotransmitters; and worsening function of the blood brain barrier, among others. Increased knowledge of these aspects will permit a better understanding of brain aging and neurodegenerative diseases in old age as complex disorders in which neurons are not the only players.
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Affiliation(s)
- Isidro Ferrer
- Department of Pathology and Experimental TherapeuticsUniversity of BarcelonaBarcelonaSpain
- Institute of NeuropathologyPathologic Anatomy Service, Bellvitge University Hospital, IDIBELL, Hospitalet de LlobregatBarcelonaSpain
- Institute of NeurosciencesUniversity of BarcelonaBarcelonaSpain
- Biomedical Network Research Center on Neurodegenerative Diseases (CIBERNED), Institute Carlos IIIMadridSpain
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13
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Guitart K, Loers G, Buck F, Bork U, Schachner M, Kleene R. Improvement of neuronal cell survival by astrocyte-derived exosomes under hypoxic and ischemic conditions depends on prion protein. Glia 2016; 64:896-910. [PMID: 26992135 DOI: 10.1002/glia.22963] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 12/18/2015] [Indexed: 02/05/2023]
Abstract
Prion protein (PrP) protects neural cells against oxidative stress, hypoxia, ischemia, and hypoglycemia. In the present study we confirm that cultured PrP-deficient neurons are more sensitive to oxidative stress than wild-type neurons and present the novel findings that wild-type, but not PrP-deficient astrocytes protect wild-type cerebellar neurons against oxidative stress and that exosomes released from stressed wild-type, but not from stressed PrP-deficient astrocytes reduce neuronal cell death induced by oxidative stress. We show that neuroprotection by exosomes of stressed astrocytes depends on exosomal PrP but not on neuronal PrP and that astrocyte-derived exosomal PrP enters into neurons, suggesting neuronal uptake of astrocyte-derived exosomes. Upon exposure of wild-type astrocytes to hypoxic or ischemic conditions PrP levels in exosomes were increased. By mass spectrometry and Western blot analysis, we detected increased levels of 37/67 kDa laminin receptor, apolipoprotein E and the ribosomal proteins S3 and P0, and decreased levels of clusterin/apolipoprotein J in exosomes from wild-type astrocytes exposed to oxygen/glucose deprivation relative to exosomes from astrocytes maintained under normoxic conditions. The levels of these proteins were not altered in exosomes from stressed PrP-deficient astrocytes relative to unstressed PrP-deficient astrocytes. These results indicate that PrP in astrocytes is a sensor for oxidative stress and mediates beneficial cellular responses, e.g. release of exosomes carrying PrP and other molecules, resulting in improved survival of neurons under hypoxic and ischemic conditions.
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Affiliation(s)
- Kathrin Guitart
- Zentrum Für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Gabriele Loers
- Zentrum Für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Friedrich Buck
- Institut Für Klinische Chemie, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Ute Bork
- Zentrum Für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Melitta Schachner
- Keck Center for Collaborative Neuroscience and Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey
- Center for Neuroscience, Shantou University Medical College, Shantou, Guangdong, China
| | - Ralf Kleene
- Zentrum Für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
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Genereux JC, Wiseman RL. Regulating extracellular proteostasis capacity through the unfolded protein response. Prion 2016; 9:10-21. [PMID: 25946012 DOI: 10.1080/19336896.2015.1011887] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The extracellular aggregation of proteins into proteotoxic oligomers and amyloid fibrils is implicated in the onset and pathology of numerous diseases referred to as amyloid diseases. All of the proteins that aggregate extracellularly in association with amyloid disease pathogenesis originate in the endoplasmic reticulum (ER) and are secreted through the secretory pathway. Disruptions in ER protein homeostasis or proteostasis (i.e., ER stress) can facilitate the aberrant secretion of misfolded protein conformations to the extracellular space and exacerbate pathologic protein aggregation into proteotoxic species. Activation of an ER stress-responsive signaling pathway, the Unfolded Protein Response (UPR), restores ER proteostasis through the transcriptional regulation of ER proteostasis pathways. In contrast, the functional role for the UPR in regulating extracellular proteostasis during ER stress is poorly defined. We recently identified ERdj3 as a UPR-regulated secreted chaperone that increases extracellular proteostasis capacity in response to ER stress, revealing a previously-unanticipated direct mechanism by which the UPR impacts extracellular proteostasis. Here, we discuss the functional implications of ERdj3 secretion on extracellular proteostasis maintenance and define the mechanisms by which ERdj3 secretion coordinates intra- and extracellular proteostasis environments during ER stress.
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Affiliation(s)
- Joseph C Genereux
- a Department of Molecular & Experimental Medicine; Department of Chemical Physiology ; The Scripps Research Institute ; La Jolla , CA USA
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15
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Llorens F, Zafar S, Ansoleaga B, Shafiq M, Blanco R, Carmona M, Grau-Rivera O, Nos C, Gelpí E, Del Río JA, Zerr I, Ferrer I. Subtype and regional regulation of prion biomarkers in sporadic Creutzfeldt-Jakob disease. Neuropathol Appl Neurobiol 2015; 41:631-45. [PMID: 25134744 DOI: 10.1111/nan.12175] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 08/04/2014] [Indexed: 11/29/2022]
Abstract
AIMS Creutzfeldt-Jakob disease (CJD) is a rapid progressive neurological disease leading to dementia and death. Prion biomarkers are altered in the cerebrospinal fluid (CSF) of CJD patients, but the pathogenic mechanisms underlying these alterations are still unknown. The present study examined prion biomarker levels in the brain and CSF of sporadic CJD (sCJD) cases and their correlation with neuropathological lesion profiles. METHODS The expression levels of 14-3-3, Tau, phospho-Tau and α-synuclein were measured in the CSF and brain of sCJD cases in a subtype- and region-specific manner. In addition, the activity of prion biomarker kinases, the expression levels of CJD hallmarks and the most frequent neuropathological sCJD findings were analysed. RESULTS Prion biomarkers levels were increased in the CSF of sCJD patients; however, correlations between mRNA, total protein and their phosphorylated forms in brain were different. The observed downregulation of the main Tau kinase, GSK3, in sCJD brain samples may help to explain the differential phospho-Tau/Tau ratios between sCJD and other dementias in the CSF. Importantly, CSF biomarkers levels do not necessarily correlate with sCJD neuropathological findings. INTERPRETATION Present findings indicate that prion biomarkers levels in sCJD tissues and their release into the CSF are differentially regulated following specific modulated responses, and suggest a functional role for these proteins in sCJD pathogenesis.
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Affiliation(s)
- Franc Llorens
- Department of Neurology, Clinical Dementia Center, University Medical School, Georg-August University and German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany.,Institute of Neuropathology, IDIBELL-University Hospital Bellvitge, University of Barcelona, Hospitalet de Llobregat, Barcelona, Spain
| | - Saima Zafar
- Department of Neurology, Clinical Dementia Center, University Medical School, Georg-August University and German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Belén Ansoleaga
- Institute of Neuropathology, IDIBELL-University Hospital Bellvitge, University of Barcelona, Hospitalet de Llobregat, Barcelona, Spain.,CIBERNED (Network Center for Biomedical Research of Neurodegenerative Diseases), Institute Carlos III, Ministry of Health, Barcelona, Spain
| | - Mohsin Shafiq
- Department of Neurology, Clinical Dementia Center, University Medical School, Georg-August University and German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Rosi Blanco
- Institute of Neuropathology, IDIBELL-University Hospital Bellvitge, University of Barcelona, Hospitalet de Llobregat, Barcelona, Spain.,CIBERNED (Network Center for Biomedical Research of Neurodegenerative Diseases), Institute Carlos III, Ministry of Health, Barcelona, Spain
| | - Marga Carmona
- Institute of Neuropathology, IDIBELL-University Hospital Bellvitge, University of Barcelona, Hospitalet de Llobregat, Barcelona, Spain.,CIBERNED (Network Center for Biomedical Research of Neurodegenerative Diseases), Institute Carlos III, Ministry of Health, Barcelona, Spain
| | - Oriol Grau-Rivera
- CJD-Unit and Alzheimer disease and other cognitive disorders Unit, Department of Neurology, Hospital Clínic, Barcelona, Spain
| | - Carlos Nos
- General Subdirectorate of Surveillance and Response to Emergencies in Public Health, Department of Public Health in Catalonia, Barcelona, Spain
| | - Ellen Gelpí
- Neurological Tissue Bank of the Biobanc-Hospital Clínic-Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - José Antonio Del Río
- CIBERNED (Network Center for Biomedical Research of Neurodegenerative Diseases), Institute Carlos III, Ministry of Health, Barcelona, Spain.,Molecular and Cellular Neurobiotechnology, Catalonian Institute for Bioengineering (IBEC), Parc Científic de Barcelona, Barcelona, Spain.,Department of Cell Biology, University of Barcelona, Barcelona, Spain
| | - Inga Zerr
- Department of Neurology, Clinical Dementia Center, University Medical School, Georg-August University and German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Isidre Ferrer
- Institute of Neuropathology, IDIBELL-University Hospital Bellvitge, University of Barcelona, Hospitalet de Llobregat, Barcelona, Spain.,CIBERNED (Network Center for Biomedical Research of Neurodegenerative Diseases), Institute Carlos III, Ministry of Health, Barcelona, Spain
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Affiliation(s)
- Amy R. Wyatt
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia;
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Justin J. Yerbury
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia;
| | - Heath Ecroyd
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia;
| | - Mark R. Wilson
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia;
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17
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Resenberger UK, Müller V, Munter LM, Baier M, Multhaup G, Wilson MR, Winklhofer KF, Tatzelt J. The heat shock response is modulated by and interferes with toxic effects of scrapie prion protein and amyloid β. J Biol Chem 2012; 287:43765-76. [PMID: 23115236 PMCID: PMC3527961 DOI: 10.1074/jbc.m112.389007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 10/27/2012] [Indexed: 12/19/2022] Open
Abstract
The heat shock response (HSR) is an evolutionarily conserved pathway designed to maintain proteostasis and to ameliorate toxic effects of aberrant protein folding. We have studied the modulation of the HSR by the scrapie prion protein (PrP(Sc)) and amyloid β peptide (Aβ) and investigated whether an activated HSR or the ectopic expression of individual chaperones can interfere with PrP(Sc)- or Aβ-induced toxicity. First, we observed different effects on the HSR under acute or chronic exposure of cells to PrP(Sc) or Aβ. In chronically exposed cells the threshold to mount a stress response was significantly increased, evidenced by a decreased expression of Hsp72 after stress, whereas an acute exposure lowered the threshold for stress-induced expression of Hsp72. Next, we employed models of PrP(Sc)- and Aβ-induced toxicity to demonstrate that the induction of the HSR ameliorates the toxic effects of both PrP(Sc) and Aβ. Similarly, the ectopic expression of cytosolic Hsp72 or the extracellular chaperone clusterin protected against PrP(Sc)- or Aβ-induced toxicity. However, toxic signaling induced by a pathogenic PrP mutant located at the plasma membrane was prevented by an activated HSR or Hsp72 but not by clusterin, indicating a distinct mode of action of this extracellular chaperone. Our study supports the notion that different pathological protein conformers mediate toxic effects via similar cellular pathways and emphasizes the possibility to exploit the heat shock response therapeutically.
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Affiliation(s)
- Ulrike K. Resenberger
- From the Neurobiochemistry, Adolf-Butenandt-Institute, Ludwig-Maximilians-University Munich, D-80336 Munich, Germany
| | - Veronika Müller
- From the Neurobiochemistry, Adolf-Butenandt-Institute, Ludwig-Maximilians-University Munich, D-80336 Munich, Germany
| | - Lisa M. Munter
- Institut für Chemie und Biochemie, Freie Universität, 14195 Berlin, Germany
- the Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3A0G4, Canada
| | | | - Gerd Multhaup
- Institut für Chemie und Biochemie, Freie Universität, 14195 Berlin, Germany
- the Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3A0G4, Canada
| | - Mark R. Wilson
- the School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia, and
| | - Konstanze F. Winklhofer
- From the Neurobiochemistry, Adolf-Butenandt-Institute, Ludwig-Maximilians-University Munich, D-80336 Munich, Germany
- the German Center for Neurodegenerative Diseases (DZNE), 80336 Munich, Germany
| | - Jörg Tatzelt
- From the Neurobiochemistry, Adolf-Butenandt-Institute, Ludwig-Maximilians-University Munich, D-80336 Munich, Germany
- the German Center for Neurodegenerative Diseases (DZNE), 80336 Munich, Germany
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18
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Roles of Extracellular Chaperones in Amyloidosis. J Mol Biol 2012; 421:499-516. [DOI: 10.1016/j.jmb.2012.01.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 01/02/2012] [Accepted: 01/03/2012] [Indexed: 01/24/2023]
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19
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Charnay Y, Imhof A, Vallet PG, Kovari E, Bouras C, Giannakopoulos P. Clusterin in neurological disorders: Molecular perspectives and clinical relevance. Brain Res Bull 2012; 88:434-43. [DOI: 10.1016/j.brainresbull.2012.05.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 05/07/2012] [Indexed: 10/28/2022]
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20
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Clusterin Overexpression and Its Possible Protective Role in Transthyretin Deposition in Familial Amyloidotic Polyneuropathy. J Neuropathol Exp Neurol 2011; 70:1097-106. [DOI: 10.1097/nen.0b013e31823a44f4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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21
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Faucheux BA, Morain E, Diouron V, Brandel JP, Salomon D, Sazdovitch V, Privat N, Laplanche JL, Hauw JJ, Haïk S. Quantification of surviving cerebellar granule neurones and abnormal prion protein (PrPSc) deposition in sporadic Creutzfeldt-Jakob disease supports a pathogenic role for small PrPSc deposits common to the various molecular subtypes. Neuropathol Appl Neurobiol 2011; 37:500-12. [PMID: 21450052 DOI: 10.1111/j.1365-2990.2011.01179.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
AIMS Neuronal death is a major neuropathological hallmark in prion diseases. The association between the accumulation of the disease-related prion protein (PrP(Sc) ) and neuronal loss varies within the wide spectrum of prion diseases and their experimental models. In this study, we investigated the relationships between neuronal loss and PrP(Sc) deposition in the cerebellum from cases of the six subtypes of sporadic Creutzfeldt-Jakob disease (sCJD; n=100) that can be determined according to the M129V polymorphism of the human prion protein gene (PRNP) and PrP(Sc) molecular types. METHODS The numerical density of neurones was estimated with a computer-assisted image analysis system and the accumulation of PrP(Sc) deposits was scored. RESULTS The scores of PrP(Sc) immunoreactive deposits of the punctate type (synaptic type) were correlated with neurone counts - the higher the score the higher the neuronal loss - in all sCJD subtypes. Large 5- to 50-µm-wide deposits (focal type) were found in sCJD-MV2 and sCJD-VV2 subtypes, and occasionally in a few cases of the other studied groups. By contrast, the highest scores for 5- to 50-µm-wide deposits observed in sCJD-MV2 subtype were not associated with higher neuronal loss. In addition, these scores were inversely correlated with neuronal counts in the sCJD-VV2 subtype. CONCLUSIONS These results support a putative pathogenic role for small PrP(Sc) deposits common to the various sCJD subtypes. Furthermore, the observation of a lower loss of neurones associated with PrP(Sc) type-2 large deposits is consistent with a possible 'protective' role of aggregated deposits in both sCJD-MV2 and sCJD-VV2 subtypes.
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Affiliation(s)
- B A Faucheux
- Assistance Publique - Hôpitaux de Paris (AP-HP), Laboratoire de Neuropathologie, Hôpital de la Salpêtrière, 47 boulevard de l'Hôpital Centre de Recherche de l'Institut du Cerveau et de la Moelle, INSERM UMRS975, CNRS UMR7225, Paris, France.
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Abstract
The maintenance of the levels and correct folding state of proteins (proteostasis) is a fundamental prerequisite for life. Life has evolved complex mechanisms to maintain proteostasis and many of these that operate inside cells are now well understood. The same cannot yet be said of corresponding processes in extracellular fluids of the human body, where inappropriate protein aggregation is known to underpin many serious diseases such as Alzheimer's disease, type II diabetes and prion diseases. Recent research has uncovered a growing family of abundant extracellular chaperones in body fluids which appear to selectively bind to exposed regions of hydrophobicity on misfolded proteins to inhibit their toxicity and prevent them from aggregating to form insoluble deposits. These extracellular chaperones are also implicated in clearing the soluble, stabilized misfolded proteins from body fluids via receptor-mediated endocytosis for subsequent lysosomal degradation. Recent work also raises the possibility that extracellular chaperones may play roles in modulating the immune response. Future work will better define the in vivo functions of extracellular chaperones in proteostasis and immunology and pave the way for the development of new treatments for serious diseases.
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Lamoureux L, Simon SLR, Plews M, Stobart M, Groschup M, Czub S, Graham C, Knox JD. Analysis of clusterin glycoforms in the urine of BSE-infected Fleckvieh-Simmental cows. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2011; 74:138-145. [PMID: 21218342 DOI: 10.1080/15287394.2011.529063] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Currently approved tests for bovine spongiform encephalopathy (BSE) monitoring in cattle are based on the detection of the disease-related isoform of the prion protein in brain tissue and consequently are only suitable for postmortem diagnosis. Previously, to meet the demand for an antemortem test based on a matrix that would permit easy access and repeated sampling, two-dimensional differential gel electrophoresis (2D-DIGE) was used to perform an unbiased screen of bovine urine. Data demonstrated the altered abundance of particular isoforms of the multifunctional glycoprotein clusterin in urine samples obtained from BSE-infected and age-matched Fleckvieh-Simmental cattle. Unfortunately, the use of particular isoforms of a relatively abundant urine protein such as clusterin for diagnosis faces many of the same challenges encountered in tests based on PrP(d) detection. In both instances the specific detection of the marker protein is complicated by the high background levels of proteins with identical amino acid sequences, but lacking the disease-specific posttranslational modifications or configuration. The goal of the current study was to define the distinguishing characteristics of the clusterin isoforms observed. Biochemical and mass spectrometry analyses in combination with the generation of bovine clusterin subunit-specific antibodies enabled us to demonstrate that it was β-subunits of clusterin possessing N-linked glycans of complex structure that exhibited differential abundance in response to BSE infection. The charateristic highly glycosylated clusterin β-subunit was detectable as early as 16 mo post infection (mpi) by one-dimensional (1D) Western blot analysis of urine obtained from BSE-infected cattle.
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Affiliation(s)
- Lise Lamoureux
- Prion Diseases Program, Public Health Agency of Canada, Winnipeg, Canada
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24
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Dabbs RA, Wyatt AR, Yerbury JJ, Ecroyd H, Wilson MR. Extracellular Chaperones. Top Curr Chem (Cham) 2010. [PMID: 21516385 DOI: 10.1007/128_2010_85] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The maintenance of the levels and correct folding state of proteins (proteostasis) is a fundamental prerequisite for life. Life has evolved complex mechanisms to maintain proteostasis and many of these that operate inside cells are now well understood. The same cannot yet be said of corresponding processes in extracellular fluids of the human body, where inappropriate protein aggregation is known to underpin many serious diseases such as Alzheimer's disease, type II diabetes and prion diseases. Recent research has uncovered a growing family of abundant extracellular chaperones in body fluids which appear to selectively bind to exposed regions of hydrophobicity on misfolded proteins to inhibit their toxicity and prevent them from aggregating to form insoluble deposits. These extracellular chaperones are also implicated in clearing the soluble, stabilized misfolded proteins from body fluids via receptor-mediated endocytosis for subsequent lysosomal degradation. Recent work also raises the possibility that extracellular chaperones may play roles in modulating the immune response. Future work will better define the in vivo functions of extracellular chaperones in proteostasis and immunology and pave the way for the development of new treatments for serious diseases.
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25
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Elliott DA, Weickert CS, Garner B. Apolipoproteins in the brain: implications for neurological and psychiatric disorders. ACTA ACUST UNITED AC 2010; 51:555-573. [PMID: 21423873 DOI: 10.2217/clp.10.37] [Citation(s) in RCA: 143] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The brain is the most lipid-rich organ in the body and, owing to the impermeable nature of the blood-brain barrier, lipid and lipoprotein metabolism within this organ is distinct from the rest of the body. Apolipoproteins play a well-established role in the transport and metabolism of lipids within the CNS; however, evidence is emerging that they also fulfill a number of functions that extend beyond lipid transport and are critical for healthy brain function. The importance of apolipoproteins in brain physiology is highlighted by genetic studies, where apolipoprotein gene polymorphisms have been identified as risk factors for several neurological diseases. Furthermore, the expression of brain apolipoproteins is significantly altered in several brain disorders. The purpose of this article is to provide an up-to-date assessment of the major apolipoproteins found in the brain (ApoE, ApoJ, ApoD and ApoA-I), covering their proposed roles and the factors influencing their level of expression. Particular emphasis is placed on associations with neurological and psychiatric disorders.
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Affiliation(s)
- David A Elliott
- Prince of Wales Medical Research Institute, Randwick, Sydney, NSW 2031, Australia
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26
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Wyatt AR, Wilson MR. Identification of human plasma proteins as major clients for the extracellular chaperone clusterin. J Biol Chem 2010; 285:3532-3539. [PMID: 19996109 PMCID: PMC2823492 DOI: 10.1074/jbc.m109.079566] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Revised: 12/02/2009] [Indexed: 11/06/2022] Open
Abstract
Clusterin (CLU) is an extracellular chaperone that is likely to play an important role in protein folding quality control. This study identified three deposition disease-associated proteins as major plasma clients for clusterin by studying CLU-client complexes formed in response to physiologically relevant stress (shear stress, approximately 36 dynes/cm(2) at 37 degrees C). Analysis of plasma samples by size exclusion chromatography indicated that (i) relative to control plasma, stressed plasma contained proportionally more soluble protein species of high molecular weight, and (ii) high molecular weight species were far more abundant when proteins purified by anti-CLU immunoaffinity chromatography from stressed plasma were compared with those purified from control plasma. SDS-PAGE and Western blot analyses indicated that a variety of proteins co-purified with CLU from both stressed and control plasma; however, several proteins were uniquely present or much more abundant when plasma was stressed. These proteins were identified by mass spectrometry as ceruloplasmin, fibrinogen, and albumin. Immunodot blot analysis of size exclusion chromatography fractionated plasma suggested that CLU-client complexes generated in situ are very large and may reach >or=4 x 10(7) Da. Lastly, sandwich enzyme-linked immunosorbent assay detected complexes containing CLU and ceruloplasmin, fibrinogen, or albumin in stressed but not control plasma. We have previously proposed that CLU-client complexes serve as vehicles to dispose of damaged misfolded extracellular proteins in vivo via receptor-mediated endocytosis. A better understanding of these mechanisms is likely to ultimately lead to the identification of new therapies for extracellular protein deposition disorders.
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Affiliation(s)
- Amy R Wyatt
- From the School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Mark R Wilson
- From the School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia.
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Wyatt A, Yerbury J, Poon S, Dabbs R, Wilson M. Chapter 6: The chaperone action of Clusterin and its putative role in quality control of extracellular protein folding. Adv Cancer Res 2010; 104:89-114. [PMID: 19878774 DOI: 10.1016/s0065-230x(09)04006-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The function(s) of clusterin may depend upon its topological location. A variety of intracellular "isoforms" of clusterin have been reported but further work is required to better define their identity. The secreted form of clusterin has a potent ability to inhibit both amorphous and amyloid protein aggregation. In the case of amorphous protein aggregation, clusterin forms stable, soluble high-molecular-weight complexes with misfolded client proteins. Clusterin expression is increased during many types of physiological and pathological stresses and is thought to function as an extracellular chaperone (EC). The pathology of a variety of serious human diseases is thought to arise as a consequence of the inappropriate aggregation of specific extracellular proteins (e.g., Abeta peptide in Alzheimer's disease and beta(2)-microglobulin in dialysis-related amyloidosis). We have proposed that together with other abundant ECs (e.g., haptoglobin and alpha(2)-macroglobulin), clusterin forms part of a previously unknown quality-control (QC) system for protein folding that mediates the recognition and disposal of extracellular misfolded proteins via receptor-mediated endocytosis and lysosomal degradation. Characterizing the mechanisms of this extracellular QC system will thus have major implications for our understanding of diseases of this type and may eventually lead to the development of new therapies.
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Affiliation(s)
- Amy Wyatt
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
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Abstract
Myofibrillar myopathies (MFMs) are a group of heterogeneous muscle disorders morphologically defined by the presence of foci of dissolution of the myofibrils, accumulation of the products of myofibrillar degradation and ectopic expression of multiple proteins. MFMs represent the paradigm of conformational protein diseases of skeletal and cardiac muscles. Protein aggregation in MFMs is now considered to be the result of a failure of the extralysosomal proteolytic degradation system. Several factors including mutant proteins, aggresome formation and oxidative stress may compromise the ubiquitin-proteasome system, promoting the accumulation of potentially toxic protein aggregates within muscle cells.
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Affiliation(s)
- Montse Olivé
- Institut de Neuropatologia, IDIBELL-Hospital Universitari de Bellvitge, Hospitalet de Llobregat, Barcelona, Spain.
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Nuutinen T, Suuronen T, Kauppinen A, Salminen A. Clusterin: a forgotten player in Alzheimer's disease. ACTA ACUST UNITED AC 2009; 61:89-104. [PMID: 19651157 DOI: 10.1016/j.brainresrev.2009.05.007] [Citation(s) in RCA: 202] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Revised: 05/13/2009] [Accepted: 05/14/2009] [Indexed: 11/16/2022]
Abstract
Clusterin, also known as apolipoprotein J, is a versatile chaperone molecule which contains several amphipathic and coiled-coil alpha-helices, typical characteristics of small heat shock proteins. In addition, clusterin has three large intrinsic disordered regions, so-called molten globule domains, which can stabilize stressed protein structures. Twenty years ago, it was demonstrated that the expression of clusterin was clearly increased in Alzheimer's disease (AD). Later it was observed that clusterin can bind amyloid-beta peptides and prevent their fibrillization. Clusterin is also involved in the clearance of amyloid-beta peptides and fibrils by binding to megalin receptors and enhancing their endocytosis within glial cells. Clusterin is a complement inhibitor and can suppress complement activation observed in AD. Clusterin is also present in lipoprotein particles and regulates cholesterol and lipid metabolism of brain which is disturbed in AD. Clusterin is a stress-induced chaperone which is normally secreted but in conditions of cellular stress, it can be transported to cytoplasm where it can bind to Bax protein and inhibit neuronal apoptosis. Clusterin can also bind to Smad2/3 proteins and potentiate the neuroprotective TGFbeta signaling. An alternative splicing can produce a variant isoform of clusterin which can be translocated to nuclei where it induces apoptosis. The role of nuclear clusterin in AD needs to be elucidated. We will review here the extensive literature linking clusterin to AD and examine the recent progress in clusterin research with the respect to AD pathology. Though clusterin can be viewed as a multipotent guardian of brain, it is unable to prevent the progressive neuropathology in chronic AD.
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Affiliation(s)
- Tapio Nuutinen
- Department of Neuroscience and Neurology, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland
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30
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Wyatt AR, Yerbury JJ, Wilson MR. Structural characterization of clusterin-chaperone client protein complexes. J Biol Chem 2009; 284:21920-21927. [PMID: 19535339 DOI: 10.1074/jbc.m109.033688] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Clusterin (CLU) is a potent extracellular chaperone that inhibits protein aggregation and precipitation otherwise caused by physical or chemical stresses (e.g. heat, reduction). This action involves CLU forming soluble high molecular weight (HMW) complexes with the client protein. Other than their unquantified large size, the physical characteristics of these complexes were previously unknown. In this study, HMW CLU-citrate synthase (CS), HMW CLU-fibrinogen (FGN), and HMW CLU-glutathione S-transferase (GST) complexes were generated in vitro, and their structures studied using size exclusion chromatography (SEC), ELISA, SDS-PAGE, dynamic light scattering (DLS), bisANS fluorescence, and circular dichroism spectrophotometry (CD). Densitometry of Coomassie Blue-stained SDS-PAGE gels indicated that all three HMW CLU-client protein complexes had an approximate mass ratio of 1:2 (CLU:client protein). SEC indicated that all three clients formed complexes with CLU>or=4x10(7) Da; however, DLS estimated HMW CLU-FGN to have a diameter of 108.57+/-18.09 nm, while HMW CLU-CS and HMW CLU-GST were smaller with estimated diameters of 51.06+/-6.87 nm and 52.61+/-7.71 nm, respectively. Measurements of bisANS fluorescence suggest that the chaperone action of CLU involves preventing the exposure to aqueous solvent of hydrophobic regions that are normally exposed by the client protein during heat-induced unfolding. CD analysis indicated that, depending on the individual client protein, CLU may interact with a variety of intermediates on protein unfolding pathways with different amounts of native secondary structure. In vivo, soluble complexes like those studied here are likely to serve as vehicles to dispose of otherwise dangerous aggregation-prone misfolded extracellular proteins.
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Affiliation(s)
- Amy R Wyatt
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Justin J Yerbury
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Mark R Wilson
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
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Xu F, Karnaukhova E, Vostal JG. Human cellular prion protein interacts directly with clusterin protein. Biochim Biophys Acta Mol Basis Dis 2008; 1782:615-20. [DOI: 10.1016/j.bbadis.2008.08.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 07/25/2008] [Accepted: 08/05/2008] [Indexed: 02/07/2023]
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Abstract
Myofibrillar myopathies (MFMs) are clinically and genetically heterogeneous muscle disorders that are defined morphologically by the presence of foci of myofibril dissolution, accumulation of myofibrillar degradation products, and ectopic expression of multiple proteins. MFMs are the paradigm of conformational protein diseases of the skeletal (and cardiac) muscles characterised by intracellular protein accumulation in muscle cells. Understanding of this group of disorders has advanced in recent years through the identification of causative mutations in various genes, most of which encode proteins of the sarcomeric Z-disc, including desmin, alphaB-crystallin, myotilin, ZASP and filamin C. This review focuses on the MFMs arising from defects in these proteins, summarising genetic and clinical features of the disorders and then discussing emerging understanding of the molecular pathogenic mechanisms leading to muscle fibre degeneration. Defective extralysosomal degradation of proteins is now recognised as an important element in this process. Several factors--including mutant proteins, a defective ubiquitin-proteasome system, aggresome formation, mutant ubiquitin, p62, oxidative stress and abnormal regulation of some transcription factors--are thought to participate in the cascade of events occurring in muscle fibres in MFMs.
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Armstrong RA, Lantos PL, Cairns NJ. What determines the molecular composition of abnormal protein aggregates in neurodegenerative disease? Neuropathology 2008; 28:351-65. [PMID: 18433435 DOI: 10.1111/j.1440-1789.2008.00916.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Abnormal protein aggregates, in the form of either extracellular plaques or intracellular inclusions, are an important pathological feature of the majority of neurodegenerative disorders. The major molecular constituents of these lesions, viz., beta-amyloid (Abeta), tau, and alpha-synuclein, have played a defining role in the diagnosis and classification of disease and in studies of pathogenesis. The molecular composition of a protein aggregate, however, is often complex and could be the direct or indirect consequence of a pathogenic gene mutation, be the result of cell degeneration, or reflect the acquisition of new substances by diffusion and molecular binding to existing proteins. This review examines the molecular composition of the major protein aggregates found in the neurodegenerative diseases including the Abeta and prion protein (PrP) plaques found in Alzheimer's disease (AD) and prion disease, respectively, and the cellular inclusions found in the tauopathies and synucleinopathies. The data suggest that the molecular constituents of a protein aggregate do not directly cause cell death but are largely the consequence of cell degeneration or are acquired during the disease process. These findings are discussed in relation to diagnosis and to studies of to disease pathogenesis.
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Yerbury JJ, Poon S, Meehan S, Thompson B, Kumita JR, Dobson CM, Wilson MR. The extracellular chaperone clusterin influences amyloid formation and toxicity by interacting with prefibrillar structures. FASEB J 2007; 21:2312-22. [PMID: 17412999 DOI: 10.1096/fj.06-7986com] [Citation(s) in RCA: 238] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Clusterin is an extracellular chaperone present in all disease-associated extracellular amyloid deposits, but its roles in amyloid formation and protein deposition in vivo are poorly understood. The current study initially aimed to characterize the effects of clusterin on amyloid formation in vitro by a panel of eight protein substrates. Two of the substrates (Alzheimer's beta peptide and a PI3-SH3 domain) were then used in further experiments to examine the effects of clusterin on amyloid cytotoxicity and to probe the mechanism of clusterin action. We show that clusterin exerts potent effects on amyloid formation, the nature and extent of which vary greatly with the clusterin:substrate ratio, and provide evidence that these effects are exerted via interactions with prefibrillar species that share common structural features. Proamyloidogenic effects of clusterin appear to be restricted to conditions in which the substrate protein is present at a very large molar excess; under these same conditions, clusterin coincorporates with substrate protein into insoluble aggregates. However, when clusterin is present at much higher but still substoichiometric levels (e.g., a molar ratio of clusterin:substrate=1:10), it potently inhibits amyloid formation and provides substantial cytoprotection. These findings suggest that clusterin is an important element in the control of extracellular protein misfolding.
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Affiliation(s)
- Justin J Yerbury
- School of Biological Sciences, University of Wollongong, Wollongong, Australia
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35
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Zhadobov M, Sauleau R, Le Coq L, Debure L, Thouroude D, Michel D, Le Dréan Y. Low-power millimeter wave radiations do not alter stress-sensitive gene expression of chaperone proteins. Bioelectromagnetics 2007; 28:188-96. [PMID: 17080454 DOI: 10.1002/bem.20285] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This article reports experimental results on the influence of low-power millimeter wave (MMW) radiation at 60 GHz on a set of stress-sensitive gene expression of molecular chaperones, namely clusterin (CLU) and HSP70, in a human brain cell line. Selection of the exposure frequency is determined by its near-future applications for the new broadband civil wireless communication systems including wireless local area networks (WLAN) for domestic and professional uses. Frequencies around 60 GHz are strongly attenuated in the earth's atmosphere and such radiations represent a new environmental factor. An exposure system operating in V-band (50-75 GHz) was developed for cell exposure. U-251 MG glial cell line was sham-exposed or exposed to MMW radiation for different durations (1-33 h) and two different power densities (5.4 microW/cm(2) or 0.54 mW/cm(2)). As gene expression is a multiple-step process, we analyzed chaperone proteins induction at different levels. First, using luciferase reporter gene, we investigated potential effect of MMWs on the activation of transcription factors (TFs) and gene promoter activity. Next, using RT-PCR and Western blot assays, we verified whether MMW exposure could alter RNA accumulation, translation, or protein stability. Experimental data demonstrated the absence of significant modifications in gene transcription, mRNA, and protein amount for the considered stress-sensitive genes for the exposure durations and power densities investigated. The main results of this study suggest that low-power 60 GHz radiation does not modify stress-sensitive gene expression of chaperone proteins.
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Affiliation(s)
- M Zhadobov
- Institute of Electronics and Telecommunications of Rennes (IETR), University of Rennes I, Campus de Beaulieu, bâtiment 11D, 263 avenue du Général Leclerc, 35042 Rennes Cedex, France.
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Ishikawa T, Zhu BL, Miyaishi S, Ishizu H, Maeda H. Increase in clusterin-containing follicles in the adenohypophysis of drug abusers. Int J Legal Med 2006; 121:395-402. [PMID: 17115171 DOI: 10.1007/s00414-006-0138-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Accepted: 09/26/2006] [Indexed: 11/30/2022]
Abstract
The hypothalamic-pituitary-adrenocortical (HPA) system in drug abusers may be affected due to disorders of the hypothalamic dopaminergic system. The present study investigated alterations in the adenohypophysis of middle-aged drug abusers (40-60 years of age), using clusterin-containing mixed cell-follicles as the indicator, in which clusterin (apolipoprotein J) is a multifunctional glycoprotein related to neurodegeneration. The paraffin-embedded adenohypophyses of methamphetamine and psychotropic drug abusers (n = 76) were compared with those of non-abusers (n = 82). The number of follicles was larger in drug abusers independent of the immediate cause of death, although the size was not significantly different. When cell types forming the follicles were immunohistochemically examined, drug abusers showed an increase of prolactin (PRL) cells and gonadotroph cells and a reciprocal decrease of growth hormone cells, suggesting hypofunction of dopaminergic neurons in the hypothalamus, while there was no change in the adrenocorticotropic hormone and thyroid-stimulating hormone cells. These increases of the clusterin-containing follicles and PRL cells in the follicles may be related to the dysfunction of dopaminergic neurons in the hypothalamus of chronic drug abusers and may be useful for investigating drug abuse in forensic casework.
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Affiliation(s)
- Takaki Ishikawa
- Department of Legal Medicine, Osaka City University Medical School, Asahi-machi 1-4-3, Abeno, Osaka, 545-8585, Japan.
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Piubelli C, Fiorini M, Zanusso G, Milli A, Fasoli E, Monaco S, Righetti PG. Searching for markers of Creutzfeldt-Jakob disease in cerebrospinal fluid by two-dimensional mapping. Proteomics 2006; 6 Suppl 1:S256-61. [PMID: 16511811 DOI: 10.1002/pmic.200500294] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Differential proteomic analysis has been performed on the cerebrospinal fluid (CSF) of six healthy and six patients suffering form sporadic Creutzfeldt-Jakob disease (sCJD), age- and sex-matched, after immuno-subtraction of albumin and immunoglobulins. These maps have revealed 28 polypeptide chains differentially modulated in the sCJD samples, of which 10 appeared to be up-regulated, the remaining 18 being down-regulated. Among those, 13 could be identified upon digestion and MALDI-TOF, MS analysis. In addition, the strong modulation of cystatin C was also confirmed by immunoblot analysis and the highly altered level of the 14-3-3 proteins that escaped detection by 2-D mapping, could be assessed by Western blots and immuno-detection of monomeric and homo- and hetero-dimeric 14-3-3 isotypes. In search for a panel of potential markers for sCJD, we highlight cystatin C, 14-3-3 proteins, transferrin, ubiquitin, Apoliprotein J and perhaps some of the still unidentified, but strongly modulated polypeptide chains detected in the differential map.
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Affiliation(s)
- Chiara Piubelli
- Department of Neurological and Visual Sciences, Section of Neurology, University of Verona, Verona, Italy
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38
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Ecroyd H, Belghazi M, Dacheux JL, Gatti JL. The epididymal soluble prion protein forms a high-molecular-mass complex in association with hydrophobic proteins. Biochem J 2006; 392:211-9. [PMID: 16029166 PMCID: PMC1317680 DOI: 10.1042/bj20050459] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have shown previously that a 'soluble' form of PrP (prion protein), not associated with membranous vesicles, exists in the male reproductive fluid [Ecroyd, Sarradin, Dacheux and Gatti (2004) Biol. Reprod. 71, 993-1001]. Attempts to purify this 'soluble' PrP indicated that it behaves like a high-molecular-mass complex of more than 350 kDa and always co-purified with the same set of proteins. The main associated proteins were sequenced by MS and were found to match to clusterin (apolipoprotein J), BPI (bacterial permeability-increasing protein), carboxylesterase-like urinary excreted protein (cauxin), beta-mannosidase and beta-galactosidase. Immunoblotting and enzymatic assay confirmed the presence of clusterin and a cauxin-like protein and showed that a 17 kDa hydrophobic epididymal protein was also associated with this complex. These associated proteins were not separated by a high ionic strength treatment but were by 2-mercaptoethanol, probably due to its action on reducing disulphide bonds that maintain the interaction of components of the complex. Our results suggest that the associated PrP retains its GPI (glycosylphosphatidylinositol) anchor, in contrast with brain-derived PrP, and that it is resistant to cleavage by phosphatidylinositol-specific phospholipase C. Based on these results, the identity of the associated proteins and the overall biochemical properties of this protein ensemble, we suggest that 'soluble' PrP can form protein complexes that are maintained by hydrophobic interactions, in a similar manner to lipoprotein vesicles or micellar complexes.
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Affiliation(s)
- Heath Ecroyd
- *Gamète Male et Fertilité, Institut National de la Recherche Agronomique, INRA-Nouzilly, 37380 Monnaie, France
| | - Maya Belghazi
- †Service de Spectrométrie de Masse pour la Protéomique, UMR 6175, INRA-CNRS-Haras Nationaux-Université de Tours, Station de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique, INRA-Nouzilly, 37380 Monnaie, France
| | - Jean-Louis Dacheux
- *Gamète Male et Fertilité, Institut National de la Recherche Agronomique, INRA-Nouzilly, 37380 Monnaie, France
| | - Jean-Luc Gatti
- *Gamète Male et Fertilité, Institut National de la Recherche Agronomique, INRA-Nouzilly, 37380 Monnaie, France
- To whom correspondence should be addressed (email )
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Pumarola M, Vidal E, Trens JM, Serafín A, Marquez M, Ferrer I. Neuronal intranuclear inclusion disease in a horse. Acta Neuropathol 2005; 110:191-5. [PMID: 15971054 DOI: 10.1007/s00401-005-1033-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2005] [Revised: 04/18/2005] [Accepted: 04/18/2005] [Indexed: 11/28/2022]
Abstract
Neuronal intranuclear inclusion disease (NIID) is reported in a 16-year-old Pure Spanish breed female horse suffering from progressive ataxia and motor deficiencies. The neuropathological study revealed NIIs throughout the central nervous system, although mainly in the brain stem and spinal cord. This distribution did not correlate with neuron loss, which was marked in the hippocampus and moderate in the neocortex, particularly in the occipital cortex. As in humans, NIIs in the horse were hyaline autofluorescent inclusions composed of non-membrane-bound aggregates of filaments and fine granules. NIIs were stained with anti-ubiquitin and anti-clusterin antibodies. In addition, NIIs were stained with antibodies raised against subunits of the 19S and PA28, but not of the 20S, components of the proteasome. These observations indicate similarities between NIID in humans and horses, and suggest that clusterin and abnormal ubiquitin-proteasomal expression participate in NII formation.
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Affiliation(s)
- M Pumarola
- Animal Tissue Bank of Catalunya, Department of Animal Medicine and Surgery, Universitat Autònoma de Barcelona, 08193, Bellaterra (Cerdanyola del Vallès) Barcelona, Spain.
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Ferrer I, Carmona M, Blanco R, Moreno D, Torrejón-Escribano B, Olivé M. Involvement of clusterin and the aggresome in abnormal protein deposits in myofibrillar myopathies and inclusion body myositis. Brain Pathol 2005; 15:101-8. [PMID: 15912881 PMCID: PMC8095801 DOI: 10.1111/j.1750-3639.2005.tb00504.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Myofibrillar myopathies (MM) are characterized morphologically by the presence of non-hyaline structures corresponding to foci of dissolution of myofibrils, and hyaline lesions composed of aggregates of compacted and degraded myofibrillar elements. Inclusion body myositis (IBM) is characterized by the presence of rimmed vacuoles, eosinophilic inclusions in the cytoplasm, rare intranuclear inclusions, and by the accumulation of several abnormal proteins. Recent studies have demonstrated impaired proteasomal expression and activity in MM and IBM, thus accounting, in part, for the abnormal protein accumulation in these diseases. The present study examines other factors involved in protein aggregation in MM and IBM. Clusterin is a multiple-function protein which participates in Abeta-amyloid, PrP(res) and a-synuclein aggregation in Alzheimer disease, prionopathies and a-synucleinopathies, respectively. gamma-Tubulin is present in the centrosome and is an intracellular marker of the aggresome. Moderate or strong clusterin immunoreactivity has been found in association with abnormal protein deposits, as revealed by immunohistochemistry, single and double-labeling immunofluorescence and confocal microscopy, in MM and IBM, and in target structures in denervation atrophy. Gamma-Tubulin has also been observed in association with abnormal protein deposits in MM, IBM, and in target fibers in denervation atrophy. These morphological findings are accompanied by increased expression of clusterin and gamma-tubulin in muscle homogenates of MM and IBM cases, as revealed by gel electrophoresis and Western blots. Together, these observations demonstrate involvement of clusterin in protein aggregates, and increased expression of aggresome markers in association with abnormal protein inclusions in MM and IBM and in targets, as crucial events related to the pathogenesis of abnormal protein accumulation and degradation in these muscular diseases.
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Affiliation(s)
- I Ferrer
- Institut Neuropatologia, Servei Anatomia Patològica, IDIBELL-Hospital Universitari de Bellvitge, Spain.
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Olivé M, Goldfarb LG, Shatunov A, Fischer D, Ferrer I. Myotilinopathy: refining the clinical and myopathological phenotype. Brain 2005; 128:2315-26. [PMID: 15947064 DOI: 10.1093/brain/awh576] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mutations in myotilin gene (MYOT) have been associated with variable syndromes including limb girdle muscular dystrophy type 1A (LGMD1A) and a subgroup of myofibrillar myopathy (MFM/MYOT). We studied six Spanish patients from three unrelated kindreds and seven patients without family history. Three previously reported and two novel disease-associated MYOT mutations were identified in this group of patients. The disease is characterized by the onset at the age of 42-77 years with muscle weakness initially in distal or proximal leg muscles, eventually spreading to other muscle groups of the lower and upper extremities. Associated signs of cardiomyopathy, respiratory failure and peripheral neuropathy are present in a fraction of patients. Myopathological features of focal myofibrillar destruction resulting in intracytoplasmic deposits, strongly immunoreactive to myotilin, multiple rimmed and centrally or subsarcolemmally located non-rimmed vacuoles and streaming Z-lines, were observed in each patient studied. The Spanish cohort, the largest group of patients studied so far, shares phenotypic features with both LGMD1A and MFM/MYOT variants thus establishing a continuum of phenotypic manifestations characteristic of myotilinopathy, an emerging neuromuscular disorder.
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Affiliation(s)
- Montse Olivé
- Institut de Neuropatologia, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona, Spain.
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