1
|
do Amaral MJ, Mohapatra S, Passos AR, Lopes da Silva TS, Carvalho RS, da Silva Almeida M, Pinheiro AS, Wegmann S, Cordeiro Y. Copper drives prion protein phase separation and modulates aggregation. SCIENCE ADVANCES 2023; 9:eadi7347. [PMID: 37922348 PMCID: PMC10624353 DOI: 10.1126/sciadv.adi7347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 10/03/2023] [Indexed: 11/05/2023]
Abstract
Prion diseases are characterized by prion protein (PrP) transmissible aggregation and neurodegeneration, which has been linked to oxidative stress. The physiological function of PrP seems related to sequestering of redox-active Cu2+, and Cu2+ dyshomeostasis is observed in prion disease brain. It is unclear whether Cu2+ contributes to PrP aggregation, recently shown to be mediated by PrP condensation. This study indicates that Cu2+ promotes PrP condensation in live cells at the cell surface and in vitro through copartitioning. Molecularly, Cu2+ inhibited PrP β-structure and hydrophobic residues exposure. Oxidation, induced by H2O2, triggered liquid-to-solid transition of PrP:Cu2+ condensates and promoted amyloid-like PrP aggregation. In cells, overexpression of PrPC initially protected against Cu2+ cytotoxicity but led to PrPC aggregation upon extended copper exposure. Our data suggest that PrP condensates function as a buffer for copper that prevents copper toxicity but can transition into PrP aggregation at prolonged oxidative stress.
Collapse
Affiliation(s)
- Mariana Juliani do Amaral
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | | | - Aline Ribeiro Passos
- Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
| | | | | | - Marcius da Silva Almeida
- Plataforma Avançada de Biomoléculas, Centro Nacional de Biologia Estrutural e Bioimagem, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Anderson Sá Pinheiro
- Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Susanne Wegmann
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - Yraima Cordeiro
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| |
Collapse
|
2
|
Abstract
Amyloids are protein aggregates bearing a highly ordered cross β structural motif, which may be functional but are mostly pathogenic. Their formation, deposition in tissues and consequent organ dysfunction is the central event in amyloidogenic diseases. Such protein aggregation may be brought about by conformational changes, and much attention has been directed toward factors like metal binding, post-translational modifications, mutations of protein etc., which eventually affect the reactivity and cytotoxicity of the associated proteins. Over the past decade, a global effort from different groups working on these misfolded/unfolded proteins/peptides has revealed that the amino acid residues in the second coordination sphere of the active sites of amyloidogenic proteins/peptides cause changes in H-bonding pattern or protein-protein interactions, which dramatically alter the structure and reactivity of these proteins/peptides. These second sphere effects not only determine the binding of transition metals and cofactors, which define the pathology of some of these diseases, but also change the mechanism of redox reactions catalyzed by these proteins/peptides and form the basis of oxidative damage associated with these amyloidogenic diseases. The present review seeks to discuss such second sphere modifications and their ramifications in the etiopathology of some representative amyloidogenic diseases like Alzheimer's disease (AD), type 2 diabetes mellitus (T2Dm), Parkinson's disease (PD), Huntington's disease (HD), and prion diseases.
Collapse
Affiliation(s)
- Madhuparna Roy
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Arnab Kumar Nath
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Ishita Pal
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Somdatta Ghosh Dey
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| |
Collapse
|
3
|
Loh D, Reiter RJ. Melatonin: Regulation of Prion Protein Phase Separation in Cancer Multidrug Resistance. Molecules 2022; 27:705. [PMID: 35163973 PMCID: PMC8839844 DOI: 10.3390/molecules27030705] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/11/2022] [Accepted: 01/17/2022] [Indexed: 12/13/2022] Open
Abstract
The unique ability to adapt and thrive in inhospitable, stressful tumor microenvironments (TME) also renders cancer cells resistant to traditional chemotherapeutic treatments and/or novel pharmaceuticals. Cancer cells exhibit extensive metabolic alterations involving hypoxia, accelerated glycolysis, oxidative stress, and increased extracellular ATP that may activate ancient, conserved prion adaptive response strategies that exacerbate multidrug resistance (MDR) by exploiting cellular stress to increase cancer metastatic potential and stemness, balance proliferation and differentiation, and amplify resistance to apoptosis. The regulation of prions in MDR is further complicated by important, putative physiological functions of ligand-binding and signal transduction. Melatonin is capable of both enhancing physiological functions and inhibiting oncogenic properties of prion proteins. Through regulation of phase separation of the prion N-terminal domain which targets and interacts with lipid rafts, melatonin may prevent conformational changes that can result in aggregation and/or conversion to pathological, infectious isoforms. As a cancer therapy adjuvant, melatonin could modulate TME oxidative stress levels and hypoxia, reverse pH gradient changes, reduce lipid peroxidation, and protect lipid raft compositions to suppress prion-mediated, non-Mendelian, heritable, but often reversible epigenetic adaptations that facilitate cancer heterogeneity, stemness, metastasis, and drug resistance. This review examines some of the mechanisms that may balance physiological and pathological effects of prions and prion-like proteins achieved through the synergistic use of melatonin to ameliorate MDR, which remains a challenge in cancer treatment.
Collapse
Affiliation(s)
- Doris Loh
- Independent Researcher, Marble Falls, TX 78654, USA
| | - Russel J. Reiter
- Department of Cellular and Structural Biology, UT Health San Antonio, San Antonio, TX 78229, USA
| |
Collapse
|
4
|
M Passos Y, J do Amaral M, C Ferreira N, Macedo B, Chaves JAP, E de Oliveira V, P B Gomes M, L Silva J, Cordeiro Y. The interplay between a GC-rich oligonucleotide and copper ions on prion protein conformational and phase transitions. Int J Biol Macromol 2021; 173:34-43. [PMID: 33476618 DOI: 10.1016/j.ijbiomac.2021.01.097] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/06/2021] [Accepted: 01/14/2021] [Indexed: 01/28/2023]
Abstract
The prion protein (PrP) misfolding to its infectious form is critical to the development of prion diseases, whereby various ligands are suggested to participate, such as copper and nucleic acids (NA). The PrP globular domain was shown to undergo NA-driven liquid-liquid phase separation (LLPS); this latter may precede pathological aggregation. Since Cu(II) is a physiological ligand of PrP, we argue whether it modulates phase separation altogether with nucleic acids. Using recombinant PrP, we investigate the effects of Cu(II) (at 6 M equivalents) and a previously described PrP-binding GC-rich DNA (equimolarly to protein) on PrP conformation, oligomerization, and phase transitions using a range of biophysical techniques. Raman spectroscopy data reveals the formation of the ternary complex. Microscopy suggests that phase separation is mainly driven by DNA, whereas Cu(II) has no influence. Our results show that DNA can be an adjuvant, leading to the structural conversion of PrP, even in the presence of an endogenous ligand, copper. These results provide new insights into the role of Cu(II) and NA on the phase separation, structural conversion, and aggregation of PrP, which are critical events leading to neurodegeneration.
Collapse
Affiliation(s)
- Yulli M Passos
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, 21941-590, RJ, Brazil
| | - Mariana J do Amaral
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, 21941-590, RJ, Brazil
| | - Natalia C Ferreira
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, 21941-590, RJ, Brazil; Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute for Allergy and Infectious Diseases, National Institutes of Health, MT, USA
| | - Bruno Macedo
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, 21941-590, RJ, Brazil
| | - Juliana A P Chaves
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, 21941-590, RJ, Brazil
| | - Vanessa E de Oliveira
- Departamento de Ciências da Natureza, Universidade Federal Fluminense, Rio das Ostras 28890-000, RJ, Brazil
| | - Mariana P B Gomes
- Instituto de Tecnologia em Imunobiológicos, Bio-Manguinhos, FIOCRUZ, Rio de Janeiro 21040-900, Brazil
| | - Jerson L Silva
- Instituto de Bioquímica Médica, Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, RJ, Brazil
| | - Yraima Cordeiro
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, 21941-590, RJ, Brazil.
| |
Collapse
|
5
|
Schilling KM, Tao L, Wu B, Kiblen JTM, Ubilla-Rodriguez NC, Pushie MJ, Britt RD, Roseman GP, Harris DA, Millhauser GL. Both N-Terminal and C-Terminal Histidine Residues of the Prion Protein Are Essential for Copper Coordination and Neuroprotective Self-Regulation. J Mol Biol 2020; 432:4408-4425. [PMID: 32473880 PMCID: PMC7387163 DOI: 10.1016/j.jmb.2020.05.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 05/25/2020] [Accepted: 05/26/2020] [Indexed: 01/19/2023]
Abstract
The cellular prion protein (PrPC) comprises two domains: a globular C-terminal domain and an unstructured N-terminal domain. Recently, copper has been observed to drive tertiary contact in PrPC, inducing a neuroprotective cis interaction that structurally links the protein's two domains. The location of this interaction on the C terminus overlaps with the sites of human pathogenic mutations and toxic antibody docking. Combined with recent evidence that the N terminus is a toxic effector regulated by the C terminus, there is an emerging consensus that this cis interaction serves a protective role, and that the disruption of this interaction by misfolded PrP oligomers may be a cause of toxicity in prion disease. We demonstrate here that two highly conserved histidines in the C-terminal domain of PrPC are essential for the protein's cis interaction, which helps to protect against neurotoxicity carried out by its N terminus. We show that simultaneous mutation of these histidines drastically weakens the cis interaction and enhances spontaneous cationic currents in cultured cells, the first C-terminal mutant to do so. Whereas previous studies suggested that Cu2+ coordination was localized solely to the protein's N-terminal domain, we find that both domains contribute equatorially coordinated histidine residue side-chains, resulting in a novel bridging interaction. We also find that extra N-terminal histidines in pathological familial mutations involving octarepeat expansions inhibit this interaction by sequestering copper from the C terminus. Our findings further establish a structural basis for PrPC's C-terminal regulation of its otherwise toxic N terminus.
Collapse
Affiliation(s)
- Kevin M Schilling
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, CA 95064, USA
| | - Lizhi Tao
- Department of Chemistry, University of California, 1 Shields Ave., Davis, CA 95616, USA
| | - Bei Wu
- Department of Biochemistry, Boston University School of Medicine, 72 E. Concord St Silvio Conte., Boston, MA 02118, USA
| | - Joseph T M Kiblen
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, CA 95064, USA
| | - Natalia C Ubilla-Rodriguez
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, CA 95064, USA
| | - M Jake Pushie
- Department of Surgery, College of Medicine, University of Saskatchewan, 107 Wiggins Rd B419, Saskatoon, SK S7N 5E5, Canada
| | - R David Britt
- Department of Chemistry, University of California, 1 Shields Ave., Davis, CA 95616, USA
| | - Graham P Roseman
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, CA 95064, USA
| | - David A Harris
- Department of Biochemistry, Boston University School of Medicine, 72 E. Concord St Silvio Conte., Boston, MA 02118, USA.
| | - Glenn L Millhauser
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, CA 95064, USA.
| |
Collapse
|
6
|
Tau Protein as a New Regulator of Cellular Prion Protein Transcription. Mol Neurobiol 2020; 57:4170-4186. [PMID: 32683652 DOI: 10.1007/s12035-020-02025-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 07/14/2020] [Indexed: 12/15/2022]
Abstract
Cellular prion protein (PrPC) is largely responsible for transmissible spongiform encephalopathies (TSEs) when it becomes the abnormally processed and protease resistant form PrPSC. Physiological functions of PrPC include protective roles against oxidative stress and excitotoxicity. Relevantly, PrPC downregulates tau levels, whose accumulation and modification are a hallmark in the advance of Alzheimer's disease (AD). In addition to the accumulation of misfolded proteins, in the initial stages of AD-affected brains display both increased reactive oxygen species (ROS) markers and levels of PrPC. However, the factors responsible for the upregulation of PrPC are unknown. Thus, the aim of this study was to uncover the different molecular actors promoting PrPC overexpression. In order to mimic early stages of AD, we used β-amyloid-derived diffusible ligands (ADDLs) and tau cellular treatments, as well as ROS generation, to elucidate their particular roles in human PRNP promoter activity. In addition, we used specific chemical inhibitors and site-specific mutations of the PRNP promoter sequence to analyze the contribution of the main transcription factors involved in PRNP transcription under the analyzed conditions. Our results revealed that tau is a new modulator of PrPC expression independently of ADDL treatment and ROS levels. Lastly, we discovered that the JNK/c-jun-AP-1 pathway is involved in increased PRNP transcription activity by tau but not in the promoter response to ROS.
Collapse
|
7
|
Structural Consequences of Copper Binding to the Prion Protein. Cells 2019; 8:cells8080770. [PMID: 31349611 PMCID: PMC6721516 DOI: 10.3390/cells8080770] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 07/22/2019] [Accepted: 07/23/2019] [Indexed: 12/24/2022] Open
Abstract
Prion, or PrPSc, is the pathological isoform of the cellular prion protein (PrPC) and it is the etiological agent of transmissible spongiform encephalopathies (TSE) affecting humans and animal species. The most relevant function of PrPC is its ability to bind copper ions through its flexible N-terminal moiety. This review includes an overview of the structure and function of PrPC with a focus on its ability to bind copper ions. The state-of-the-art of the role of copper in both PrPC physiology and in prion pathogenesis is also discussed. Finally, we describe the structural consequences of copper binding to the PrPC structure.
Collapse
|
8
|
Megra BW, Eugenin EA, Berman JW. Inflammatory mediators reduce surface PrP c on human BMVEC resulting in decreased barrier integrity. J Transl Med 2018; 98:1347-1359. [PMID: 29959417 PMCID: PMC6163073 DOI: 10.1038/s41374-018-0090-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Revised: 05/03/2018] [Accepted: 05/05/2018] [Indexed: 12/18/2022] Open
Abstract
The cellular prion protein (PrPc) is a surface adhesion molecule expressed at junctions of various cell types including brain microvascular endothelial cells (BMVEC) that are important components of the blood-brain barrier (BBB). PrPc is involved in several physiological processes including regulation of epithelial cell barrier function and monocyte migration across BMVEC. BBB dysfunction and disruption are significant events in central nervous system (CNS) inflammatory processes including HIV neuropathogenesis. Tumor necrosis factor (TNF)-α and vascular endothelial growth factor (VEGF) are two inflammatory factors that have been implicated in the processes that affect BBB integrity. To examine the effect of inflammation on PrPc expression in BMVEC, we used these mediators and found that TNF-α and VEGF decrease surface PrPc on primary human BMVEC. We also showed that these factors decrease total PrPc protein as well as mRNA, indicating that they regulate expression of this protein by de novo synthesis. To determine the effect of PrPc loss from the surface of BMVEC on barrier integrity, we used small hairpin RNAs to knockdown PrPc. We found that the absence of PrPc from BMVEC causes increased permeability as determined by a fluorescein isothiocyanate (FITC)-dextran permeability assay. This suggests that cell surface PrPc is essential for endothelial monolayer integrity. To determine the mechanism by which PrPc downregulation leads to increased permeability of an endothelial monolayer, we examined changes in expression and localization of tight junction proteins, occludin and claudin-5, and found that decreased PrPc leads to decreased total and membrane-associated occludin and claudin-5. We propose that an additional mechanism by which inflammatory factors affect endothelial monolayer permeability is by decreasing cell-associated PrPc. This increase in permeability may have subsequent consequences that lead to CNS damage.
Collapse
Affiliation(s)
- Bezawit W. Megra
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Eliseo A. Eugenin
- Public Health Research Institute (PHRI), Newark, NJ 07103,Department of Microbiology and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers The State University of New Jersey, Newark, NJ 07103
| | - Joan W. Berman
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461,Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461
| |
Collapse
|
9
|
Boilan E, Winant V, Dumortier E, ElMoualij B, Quatresooz P, Osiewacz HD, Debacq-Chainiaux F, Toussaint O. Role of Prion protein in premature senescence of human fibroblasts. Mech Ageing Dev 2017; 170:106-113. [PMID: 28800967 DOI: 10.1016/j.mad.2017.08.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/29/2017] [Accepted: 08/03/2017] [Indexed: 01/07/2023]
Abstract
Prion protein (PrP) is essentially known for its capacity to induce neurodegenerative prion diseases in mammals caused by a conformational change in its normal cellular isoform (PrPC) into an infectious and disease-associated misfolded form, called scrapie isoform (PrPSc). Although its sequence is highly conserved, less information is available on its physiological role under normal conditions. However, increasing evidence supports a role for PrPC in the cellular response to oxidative stress. In the present study, a new link between PrP and senescence is highlighted. The role of PrP in premature senescence induced by copper was investigated. WI-38 human fibroblasts were incubated with copper sulfate (CuSO4) to trigger premature senescence. This induced an increase of PrP mRNA level, an increase of protein abundance of the normal form of PrP and a nuclear localization of the protein. Knockdown of PrP expression using specific small interfering RNA (siRNA) gave rise to appearance of several biomarkers of senescence as a senescent morphology, an increase of senescence associated β-galactosidase activity and a decrease of the cellular proliferative potential. Overall these data suggest that PrP protects cells against premature senescence induced by copper.
Collapse
Affiliation(s)
- Emmanuelle Boilan
- Unité de Recherche en Biologie Cellulaire (URBC) - Namur Research Institute for Life Sciences (Narilis), University of Namur, Belgium.
| | - Virginie Winant
- Unité de Recherche en Biologie Cellulaire (URBC) - Namur Research Institute for Life Sciences (Narilis), University of Namur, Belgium
| | - Elise Dumortier
- Unité de Recherche en Biologie Cellulaire (URBC) - Namur Research Institute for Life Sciences (Narilis), University of Namur, Belgium
| | | | | | - Heinz D Osiewacz
- Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Florence Debacq-Chainiaux
- Unité de Recherche en Biologie Cellulaire (URBC) - Namur Research Institute for Life Sciences (Narilis), University of Namur, Belgium.
| | - Olivier Toussaint
- Unité de Recherche en Biologie Cellulaire (URBC) - Namur Research Institute for Life Sciences (Narilis), University of Namur, Belgium
| |
Collapse
|
10
|
Copper- and Zinc-Promoted Interdomain Structure in the Prion Protein: A Mechanism for Autoinhibition of the Neurotoxic N-Terminus. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2017; 150:35-56. [PMID: 28838668 DOI: 10.1016/bs.pmbts.2017.06.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
The function of the cellular prion protein (PrPC), while still poorly understood, is increasingly linked to its ability to bind physiological metal ions at the cell surface. PrPC binds divalent forms of both copper and zinc through its unstructured N-terminal domain, modulating interactions between PrPC and various receptors at the cell surface and ultimately tuning downstream cellular processes. In this chapter, we briefly discuss the molecular features of copper and zinc uptake by PrPC and summarize evidence implicating these metal ions in PrP-mediated physiology. We then focus our review on recent biophysical evidence revealing a physical interaction between the flexible N-terminal and globular C-terminal domains of PrPC. This interdomain cis interaction is electrostatic in nature and is promoted by the binding of Cu2+ and Zn2+ to the N-terminal octarepeat domain. These findings, along with recent cellular studies, suggest a mechanism whereby NC interactions serve to regulate the activity and/or toxicity of the PrPC N-terminus. We discuss this potential mechanism in relation to familial prion disease mutations, lethal deletions of the PrPC central region, and neurotoxicity induced by certain globular domain ligands, including bona fide prions and toxic amyloid-β oligomers.
Collapse
|
11
|
Evans EGB, Pushie MJ, Markham KA, Lee HW, Millhauser GL. Interaction between Prion Protein's Copper-Bound Octarepeat Domain and a Charged C-Terminal Pocket Suggests a Mechanism for N-Terminal Regulation. Structure 2016; 24:1057-67. [PMID: 27265848 DOI: 10.1016/j.str.2016.04.017] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 04/19/2016] [Accepted: 04/20/2016] [Indexed: 11/29/2022]
Abstract
Copper plays a critical role in prion protein (PrP) physiology. Cu(2+) binds with high affinity to the PrP N-terminal octarepeat (OR) domain, and intracellular copper promotes PrP expression. The molecular details of copper coordination within the OR are now well characterized. Here we examine how Cu(2+) influences the interaction between the PrP N-terminal domain and the C-terminal globular domain. Using nuclear magnetic resonance and copper-nitroxide pulsed double electron-electron resonance, with molecular dynamics refinement, we localize the position of Cu(2+) in its high-affinity OR-bound state. Our results reveal an interdomain cis interaction that is stabilized by a conserved, negatively charged pocket of the globular domain. Interestingly, this interaction surface overlaps an epitope recognized by the POM1 antibody, the binding of which drives rapid cerebellar degeneration mediated by the PrP N terminus. The resulting structure suggests that the globular domain regulates the N-terminal domain by binding the Cu(2+)-occupied OR within a complementary pocket.
Collapse
Affiliation(s)
- Eric G B Evans
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - M Jake Pushie
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
| | - Kate A Markham
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Hsiau-Wei Lee
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Glenn L Millhauser
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
| |
Collapse
|
12
|
Adam P, Křížková S, Heger Z, Babula P, Pekařík V, Vaculovičoá M, Gomes CM, Kizek R, Adam V. Metallothioneins in Prion- and Amyloid-Related Diseases. J Alzheimers Dis 2016; 51:637-56. [DOI: 10.3233/jad-150984] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Pavlína Adam
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, Brno, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Technicka, Brno, Czech Republic
| | - Soňa Křížková
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, Brno, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Technicka, Brno, Czech Republic
| | - Zbyněk Heger
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, Brno, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Technicka, Brno, Czech Republic
| | - Petr Babula
- Department of Physiology, Faculty of Medicine, Masaryk University, Kamenice, Brno, Czech Republic
| | - Vladimír Pekařík
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, Brno, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Technicka, Brno, Czech Republic
| | - Markéta Vaculovičoá
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, Brno, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Technicka, Brno, Czech Republic
| | - Cláudio M. Gomes
- Faculdade de Ciências Universidade de Lisboa, Biosystems and Integrative Sciences Institute and Department of Chemistry and Biochemistry, Universidade de Lisboa, Campo Grande, Lisboa, Portugal
| | - René Kizek
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, Brno, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Technicka, Brno, Czech Republic
| | - Vojtěch Adam
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, Brno, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Technicka, Brno, Czech Republic
| |
Collapse
|
13
|
Abstract
Copper is an essential element in many biological processes. The critical functions associated with copper have resulted from evolutionary harnessing of its potent redox activity. This same property also places copper in a unique role as a key modulator of cell signal transduction pathways. These pathways are the complex sequence of molecular interactions that drive all cellular mechanisms and are often associated with the interplay of key enzymes including kinases and phosphatases but also including intracellular changes in pools of smaller molecules. A growing body of evidence is beginning to delineate the how, when and where of copper-mediated control over cell signal transduction. This has been driven by research demonstrating critical changes to copper homeostasis in many disorders including cancer and neurodegeneration and therapeutic potential through control of disease-associated cell signalling changes by modulation of copper-protein interactions. This timely review brings together for the first time the diverse actions of copper as a key regulator of cell signalling pathways and discusses the potential strategies for controlling disease-associated signalling processes using copper modulators. It is hoped that this review will provide a valuable insight into copper as a key signal regulator and stimulate further research to promote our understanding of copper in disease and therapy.
Collapse
|
14
|
Could Intracrine Biology Play a Role in the Pathogenesis of Transmissable Spongiform Encephalopathies Alzheimer’s Disease and Other Neurodegenerative Diseases? Am J Med Sci 2014; 347:312-20. [DOI: 10.1097/maj.0b013e3182a28af3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
|
15
|
Mot AI, Wedd AG, Sinclair L, Brown DR, Collins SJ, Brazier MW. Metal attenuating therapies in neurodegenerative disease. Expert Rev Neurother 2014; 11:1717-45. [DOI: 10.1586/ern.11.170] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
16
|
Kim DK, Song JW, Park JD, Choi BS. Copper induces the accumulation of amyloid-beta in the brain. Mol Cell Toxicol 2013. [DOI: 10.1007/s13273-013-0009-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
17
|
Uppington KM, Brown DR. Modelling neurodegeneration in prion disease - applications for drug development. Expert Opin Drug Discov 2013; 2:777-88. [PMID: 23488996 DOI: 10.1517/17460441.2.6.777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Prion diseases are a group of neurodegenerative diseases that affect mammals, including humans and ruminants such as sheep. They are believed to be caused by the conversion of the prion protein (PrP), a host expressed protein, into a toxic form (PrP(sc)). PrP(sc) accumulates in the brain, resulting in neuronal loss and the typical spongiform appearance of the brain. So far, there are no effective therapies available for prion diseases. This review discusses possible therapies for prion diseases and the models available for advancing research into the disease.
Collapse
Affiliation(s)
- Kay M Uppington
- University of Bath, Department of Biology and Biochemistry, Bath, Claverton Down, BA2 7AY, UK +44 1255 383133 ; +44 1225 386779 ;
| | | |
Collapse
|
18
|
Linder MC. The relationship of copper to DNA damage and damage prevention in humans. Mutat Res 2013; 733:83-91. [PMID: 23463874 DOI: 10.1016/j.mrfmmm.2012.03.010] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Copper ions are well suited to facilitate formation of reactive oxygen species (ROS) that can damage biomolecules, including DNA and chromatin. That this can occur in vitro with isolated DNA or chromatin,or by exposure of cultured mammalian cells to copper complexed with various agents, has been well demonstrated. Whether that is likely to occur in vivo is not as clear. This review addresses the question of whether and how copper ions or complexes – in forms that could be present in vivo, damage DNA and chromosome structure and/or promote epigenetic changes that can lead to pathology and diseases, including cancer and neurological conditions such as Alzheimer's disease, Lewy body dementias, and spongiform encephalopathies. This question is considered in light of our knowledge that copper-dependent enzymes are important contributors to antioxidant defense, and that the mammalian organism has robust mechanisms for maintaining constant levels of copper not only in body fluids but in its major organs. Overall,and except in unusual genetic states that lead to copper overload in specific cells (particularly those in liver), it appears that excessive intake of copper is not a significant factor in the development of disease states.
Collapse
Affiliation(s)
- Maria C Linder
- Department of Chemistry and Biochemistry, California State University, Fullerton, CA 92834-6866, USA.
| |
Collapse
|
19
|
Spevacek AR, Evans EGB, Miller JL, Meyer HC, Pelton JG, Millhauser GL. Zinc drives a tertiary fold in the prion protein with familial disease mutation sites at the interface. Structure 2013; 21:236-46. [PMID: 23290724 DOI: 10.1016/j.str.2012.12.002] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 12/04/2012] [Accepted: 12/11/2012] [Indexed: 12/21/2022]
Abstract
The cellular prion protein PrP(C) consists of two domains--a flexible N-terminal domain, which participates in copper and zinc regulation, and a largely helical C-terminal domain that converts to β sheet in the course of prion disease. These two domains are thought to be fully independent and noninteracting. Compelling cellular and biophysical studies, however, suggest a higher order structure that is relevant to both PrP(C) function and misfolding in disease. Here, we identify a Zn²⁺-driven N-terminal to C-terminal tertiary interaction in PrP(C). The C-terminal surface participating in this interaction carries the majority of the point mutations that confer familial prion disease. Investigation of mutant PrPs finds a systematic relationship between the type of mutation and the apparent strength of this domain structure. The structural features identified here suggest mechanisms by which physiologic metal ions trigger PrP(C) trafficking and control prion disease.
Collapse
Affiliation(s)
- Ann R Spevacek
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | | | | | | | | | | |
Collapse
|
20
|
Dinamarca MC, Ríos JA, Inestrosa NC. Postsynaptic Receptors for Amyloid-β Oligomers as Mediators of Neuronal Damage in Alzheimer's Disease. Front Physiol 2012; 3:464. [PMID: 23267328 PMCID: PMC3526732 DOI: 10.3389/fphys.2012.00464] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 11/22/2012] [Indexed: 11/13/2022] Open
Abstract
The neurotoxic effect of amyloid-β peptide (Aβ) over the central synapses has been described and is reflected in the decrease of some postsynaptic excitatory proteins, the alteration in the number and morphology of the dendritic spines, and a decrease in long-term potentiation. Many studies has been carried out to identify the putative Aβ receptors in neurons, and is still no clear why the Aβ oligomers only affect the excitatory synapses. Aβ oligomers bind to neurite and preferentially to the postsynaptic region, where the postsynaptic protein-95 (PSD-95) is present in the glutamatergic synapse, and interacts directly with the N-methyl-D-aspartate receptor (NMDAR) and neuroligin (NL). NL is a postsynaptic protein which binds to the presynaptic protein, neurexin to form a heterophilic adhesion complex, the disruption of this interaction affects the integrity of the synaptic contact. Structurally, NL has an extracellular domain homolog to acetylcholinesterase, the first synaptic protein that was found to interact with Aβ. In the present review we will document the interaction between Aβ and the extracellular domain of NL-1 at the excitatory synapse, as well as the interaction with other postsynaptic components, including the glutamatergic receptors (NMDA and mGluR5), the prion protein, the neurotrophin receptor, and the α7-nicotinic acetylcholine receptor. We conclude that several Aβ oligomers receptors exist at the excitatory synapse, which could be the responsible for the neurotoxic effect described for the Aβ oligomers. The characterization of the interaction between Aβ receptors and Aβ oligomers could help to understand the source of the neurologic damage observed in the brain of the Alzheimer's disease patients.
Collapse
Affiliation(s)
- Margarita C Dinamarca
- Centro de Envejecimiento y Regeneración, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile Santiago, Chile
| | | | | |
Collapse
|
21
|
Kanthasamy AG, Choi C, Jin H, Harischandra DS, Anantharam V, Kanthasamy A. Effect of divalent metals on the neuronal proteasomal system, prion protein ubiquitination and aggregation. Toxicol Lett 2012; 214:288-95. [PMID: 22995398 DOI: 10.1016/j.toxlet.2012.09.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 09/10/2012] [Accepted: 09/11/2012] [Indexed: 10/27/2022]
Abstract
The role of normal cellular prion protein (PrP) remains to be fully elucidated; however, the protein is crucial for the infection and progression of prion diseases. Recent evidence indicates that PrP is a metalloprotein since the octapeptide repeat sequences in the protein have high affinity for various divalent cations and the binding sites appear to play a role in the pathogenesis of prion diseases. In our present study, we tested several divalent metals including manganese and cadmium and determined their effects on protein degradation and protein aggregation in mouse neuronal cells expressing PrP. Cadmium was more neurotoxic than manganese following 24h exposure. Manganese did not show any significant effect on the inhibition of proteasomal activity or formation of high molecular weight ubiquitinated PrPs. Interestingly, treatment with cadmium profoundly inhibited proteasomal activity, which resulted in greatly increased formation of high molecular weight ubiquitinated PrPs. Immunohistochemical analysis also revealed a dramatic increase in formation of oligomers after cadmium treatment. Cadmium also increased the formation of ubiquitinated PrP, but it did not lead to the formation of proteinase-K resistant PrP. Collectively, our results show that a divalent metal, cadmium affects proteasomal function and PrP aggregation, which promote neurotoxicity.
Collapse
Affiliation(s)
- A G Kanthasamy
- Department of Biomedical Sciences, Iowa Center for Advanced Neurotoxicology, Iowa State University, Ames, IA 50011, USA.
| | | | | | | | | | | |
Collapse
|
22
|
Martin GR, Alvarez AL, Bashashati M, Keenan CM, Jirik FR, Sharkey KA. Endogenous cellular prion protein regulates contractility of the mouse ileum. Neurogastroenterol Motil 2012; 24:e412-24. [PMID: 22762267 DOI: 10.1111/j.1365-2982.2012.01970.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND Cellular prion protein (PrP(C) ) is expressed in the enteric nervous system (ENS), however, its physiological role has not been identified. Studies suggest that PrP(C) can function as a metal-binding protein, as absence of the protein has been linked to altered copper metabolism and atypical synaptic activity. Because copper is known to modulate smooth muscle relaxation, we tested the hypothesis that PrP(C) deficiency would alter intestinal contractility. METHODS We examined electrically evoked ileal contractility in Prnp(-/-) or wild type littermate mice and the effects of copper or copper chelation. PrP(C) expression was studied in whole mount ileal preparations of mice and guinea pigs by immunohistochemistry. KEY RESULTS Relative to wild type mice, ileal tissues of Prnp(-/-) mice exhibited reduced electrical field stimulation (EFS)-evoked contractility. Furthermore, EFS-induced relaxation, as a percentage of that induced by a nitric oxide donor, was enhanced. Addition of a copper donor to the organ bath increased, whereas the addition of a copper chelator inhibited, nitric oxide donor-induced ileal relaxation in Prnp(-/-) mice. PrP(C) was expressed on nerve fibers or terminals, and some cell bodies in the myenteric and submucosal plexuses of wild type mice. PrP(C) colocalized with a neuron-specific ectonucleotidase, nucleoside triphosphate diphosphohydrolase 3 (NTPDase3), but to only a limited extent with GFAP, a marker of enteric glia. Guinea pigs expressed PrP(C) in nerve fibers or terminals and enteric glia in the myenteric and submucosal plexuses. CONCLUSIONS & INFERENCES Our findings suggest that PrP(C) , which is abundant in the ENS, has a role in the regulation of ileal contractility.
Collapse
Affiliation(s)
- G R Martin
- Hotchkiss Brain Institute and Snyder Institute for Chronic Diseases, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.
| | | | | | | | | | | |
Collapse
|
23
|
Disruption of copper homeostasis due to a mutation of Atp7a delays the onset of prion disease. Proc Natl Acad Sci U S A 2012; 109:13733-8. [PMID: 22869751 DOI: 10.1073/pnas.1211499109] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Copper influences the pathogenesis of prion disease, but whether it is beneficial or detrimental remains controversial. Copper homeostasis is also essential for normal physiology, as highlighted by the spectrum of diseases caused by disruption of the copper transporting enzymes ATP7A and ATP7B. Here, by using a forward genetics approach in mice, we describe the isolation of three alleles of Atp7a, each with different phenotypic consequences. The mildest of the three, Atp7a(brown), was insufficient to cause lethality in hemizygotes or mottling of the coat in heterozygotes, but did lead to coat hypopigmentation and reduced copper content in the brains of hemizygous males. When challenged with Rocky Mountain Laboratory scrapie, the onset of prion disease was delayed in Atp7a(brown) mice, and significantly less proteinase-resistant prion protein was found in the brains of moribund Atp7a(brown) mice compared with WT littermates. Our results establish that ATP7A-mediated copper homeostasis is important for the formation of pathogenic proteinase-resistant prion protein.
Collapse
|
24
|
Urso E, Manno D, Serra A, Buccolieri A, Rizzello A, Danieli A, Acierno R, Salvato B, Maffia M. Role of the Cellular Prion Protein in the Neuron Adaptation Strategy to Copper Deficiency. Cell Mol Neurobiol 2012; 32:989-1001. [DOI: 10.1007/s10571-012-9815-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 02/07/2012] [Indexed: 01/15/2023]
|
25
|
Abstract
Seven mammalian purinergic receptor subunits, denoted P2X1-P2X7, and several spliced forms of these subunits have been cloned. When heterologously expressed, these cDNAs encode ATP-gated non-selective cation channels organized as trimers. All activated receptors produce cell depolarization and promote Ca(2+) influx through their pores and indirectly by activating voltage-gated calcium channels. However, the biophysical and pharmacological properties of these receptors differ considerably, and the majority of these subunits are also capable of forming heterotrimers with other members of the P2X receptor family, which confers further different properties. These channels have three ATP binding domains, presumably located between neighboring subunits, and occupancy of at least two binding sites is needed for their activation. In addition to the orthosteric binding sites for ATP, these receptors have additional allosteric sites that modulate the agonist action at receptors, including sites for trace metals, protons, neurosteroids, reactive oxygen species and phosphoinositides. The allosteric regulation of P2X receptors is frequently receptor-specific and could be a useful tool to identify P2X members in native tissues and their roles in signaling. The focus of this review is on common and receptor-specific allosteric modulation of P2X receptors and the molecular base accounting for allosteric binding sites.
Collapse
Affiliation(s)
- Claudio Coddou
- Section on Cellular Signaling, Program in Developmental Neuroscience, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-4510, USA.
| | | | | |
Collapse
|
26
|
The depletion of α and β PrP from complex mixtures. J Virol Methods 2010; 169:253-8. [PMID: 20603150 DOI: 10.1016/j.jviromet.2010.06.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 06/21/2010] [Accepted: 06/28/2010] [Indexed: 11/20/2022]
Abstract
Prion disorders occur when endogenous prion protein (PrP(C)) undergoes a conformational change from a predominantly α-helix-rich structure to an insoluble β-sheet-rich structure (PrP(Sc)). The resulting PrP(Sc) then in some way facilitates the progressive transformation of nearby PrP(C) to PrP(Sc). In time this results in the deposition of insoluble PrP(Sc) aggregates in the brain; aggregate deposition is irreversible and is ultimately fatal. Prion diseases are transmissible orally or through transplantation (including blood transfusion). Current diagnostic methods are limited in that they lack the ability to distinguish qualitatively between PrP(C) and PrP(Sc). PrP has been shown to bind divalent cations including copper and zinc, these cations are toxic and thus of limited use in the removal of PrP from solutions destined for administration to subjects. We have immobilised Fe(3+) to an inert Sepharose resin; this resin was capable of quantitatively removing endogenous and recombinant PrP(C) and recombinant β PrP from complex solutions. The low toxicity of Fe(3+) suggests that the resin described in this report may be of practical use in the depletion of PrP from blood products destined for human use.
Collapse
|
27
|
Moulis JM. Cellular mechanisms of cadmium toxicity related to the homeostasis of essential metals. Biometals 2010; 23:877-96. [DOI: 10.1007/s10534-010-9336-y] [Citation(s) in RCA: 177] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2009] [Accepted: 04/01/2010] [Indexed: 01/12/2023]
|
28
|
Singh N, Singh A, Das D, Mohan ML. Redox control of prion and disease pathogenesis. Antioxid Redox Signal 2010; 12:1271-94. [PMID: 19803746 PMCID: PMC2864664 DOI: 10.1089/ars.2009.2628] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 09/22/2009] [Accepted: 10/03/2009] [Indexed: 11/12/2022]
Abstract
Imbalance of brain metal homeostasis and associated oxidative stress by redox-active metals like iron and copper is an important trigger of neurotoxicity in several neurodegenerative conditions, including prion disorders. Whereas some reports attribute this to end-stage disease, others provide evidence for specific mechanisms leading to brain metal dyshomeostasis during disease progression. In prion disorders, imbalance of brain-iron homeostasis is observed before end-stage disease and worsens with disease progression, implicating iron-induced oxidative stress in disease pathogenesis. This is an unexpected observation, because the underlying cause of brain pathology in all prion disorders is PrP-scrapie (PrP(Sc)), a beta-sheet-rich conformation of a normal glycoprotein, the prion protein (PrP(C)). Whether brain-iron dyshomeostasis occurs because of gain of toxic function by PrP(Sc) or loss of normal function of PrP(C) remains unclear. In this review, we summarize available evidence suggesting the involvement of oxidative stress in prion-disease pathogenesis. Subsequently, we review the biology of PrP(C) to highlight its possible role in maintaining brain metal homeostasis during health and the contribution of PrP(Sc) in inducing brain metal imbalance with disease progression. Finally, we discuss possible therapeutic avenues directed at restoring brain metal homeostasis and alleviating metal-induced oxidative stress in prion disorders.
Collapse
Affiliation(s)
- Neena Singh
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | | | | | | |
Collapse
|
29
|
Toledo EM, Inestrosa NC. Activation of Wnt signaling by lithium and rosiglitazone reduced spatial memory impairment and neurodegeneration in brains of an APPswe/PSEN1DeltaE9 mouse model of Alzheimer's disease. Mol Psychiatry 2010; 15:272-85, 228. [PMID: 19621015 DOI: 10.1038/mp.2009.72] [Citation(s) in RCA: 217] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by a progressive deterioration of cognitive abilities, accumulation of the amyloid-beta-peptide (Abeta) and synaptic alterations. Treatment with lithium has been shown to provide neuroprotection against several insults, including protection against Abeta neurotoxicity in vitro. Rosiglitazone, a peroxisome proliferator activated receptor-gamma agonist, has been shown to attenuate Abeta-peptide neurotoxic effects, including the inflammatory response of microglia and astrocytes. Both types of drugs activate Wnt signaling, a pathway that has been shown to be related to AD. In this study, a double transgenic mouse model, which coexpresses APPswe and the exon 9 deletion of the presenilin 1 (PSEN1) gene, was used to examine, in vivo, the effect of lithium and rosiglitazone on Abeta neurotoxicity. Mice were tested for spatial memory, and their brain samples were used for histochemical and biochemical analysis. In this study, we report that both drugs significantly reduced (1) spatial memory impairment induced by amyloid burden; (2) Abeta aggregates and Abeta oligomers; and (3) astrocytic and microglia activation. They also prevented changes in presynaptic and postsynaptic marker proteins. Finally, both drugs activate Wnt signaling shown by the increase in beta-catenin and by the inhibition of the glycogen synthase kinase-3beta. We conclude that lithium and rosiglitazone, possibly by the activation of the Wnt signaling pathway, reduce various AD neuropathological markers and may be considered as potential therapeutic agents against the disease.
Collapse
Affiliation(s)
- E M Toledo
- Centro de Envejecimiento y Regeneración, MIFAB, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chille
| | | |
Collapse
|
30
|
Wright JA, McHugh PC, Stockbridge M, Lane S, Kralovicova S, Brown DR. Activation and repression of prion protein expression by key regions of intron 1. Cell Mol Life Sci 2009; 66:3809-20. [PMID: 19756378 PMCID: PMC11115799 DOI: 10.1007/s00018-009-0154-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Revised: 09/01/2009] [Accepted: 09/02/2009] [Indexed: 10/20/2022]
Abstract
Expression of the prion protein is necessary for infection with prion diseases. Altered expression levels may play an important role in susceptibility to infection. Therefore, understanding the mechanisms that regulate prion protein expression is of great importance. It was previously shown that expression of the prion protein is to some degree regulated by an alternative promoter within intron 1. Studies using GFP and luciferase reporter systems were undertaken to determine key sites for the repression and activation of expression of the prion protein driven by intron 1. We identified a region within intron 1 sufficient to drive prion protein expression. Our findings highlight two potential repressor regions. Both regions have binding sites for the known repressor Hes-1. Hes-1 overexpression caused a dramatic decrease in PrP protein expression. Additionally, we have identified Atox-1 as a transcription factor that upregulates prion protein expression. These findings clearly indicate that intron 1 plays a key role in regulation of prion protein expression levels.
Collapse
Affiliation(s)
- Josephine A. Wright
- Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY UK
| | - Patrick C. McHugh
- Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY UK
| | - Mark Stockbridge
- Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY UK
| | - Samantha Lane
- Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY UK
| | - Silvia Kralovicova
- Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY UK
| | - David R. Brown
- Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY UK
| |
Collapse
|
31
|
Metal ion physiopathology in neurodegenerative disorders. Neuromolecular Med 2009; 11:223-38. [PMID: 19946766 DOI: 10.1007/s12017-009-8102-1] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Accepted: 10/14/2009] [Indexed: 12/14/2022]
Abstract
Metal dyshomeostasis in the brain (BMD) has often been proposed as a possible cause for several neurodegenerative disorders (NDs). Nevertheless, the precise nature of the biochemical mechanisms of metal involvement in NDs is still largely unknown. Mounting evidence suggests that normal aging itself is characterized by, among other features, a significant degree of metal ion dysmetabolism in the brain. This is probably the result of a progressive deterioration of the metal regulatory systems and, at least in some cases, of life-long metal exposure and brain accumulation. Although alterations of metal metabolism do occur to some extent in normal aging, they appear to be highly enhanced under various neuropathological conditions, causing increased oxidative stress and favoring abnormal metal-protein interactions. Intriguingly, despite the fact that most common NDs have a distinct etiological basis, they share striking similarities as they are all characterized by a documented brain metal impairment. This review will primarily focus on the alterations of metal homeostasis that are observed in normal aging and in Alzheimer's disease. We also present a brief survey on BMD in other NDs (Amyotrophic Lateral Sclerosis, Parkinson's, and Prion Protein disease) in order to highlight what represents the most reliable evidence supporting a crucial involvement of metals in neurodegeneration. The opportunities for metal-targeted pharmacological strategies in the major NDs are briefly outlined as well.
Collapse
|
32
|
Prion metal interaction: Is prion pathogenesis a cause or a consequence of metal imbalance? Chem Biol Interact 2009; 181:282-91. [PMID: 19660443 DOI: 10.1016/j.cbi.2009.07.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 07/22/2009] [Accepted: 07/27/2009] [Indexed: 12/14/2022]
|
33
|
Taheny MJ, Izkhakov N, Vostrov AA, Quitschke WW. Two adjacent nuclear factor-binding domains activate expression from the human PRNP promoter. BMC Res Notes 2009; 2:178. [PMID: 19740434 PMCID: PMC2751769 DOI: 10.1186/1756-0500-2-178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2009] [Accepted: 09/09/2009] [Indexed: 01/15/2023] Open
Abstract
Background The transmissible spongiform encephalopathies (TSEs) comprise a group of fatal degenerative neurological diseases in humans and other mammals. After infection, the cellular prion protein isoform PrPC is converted to the pathological PrPSC scrapie isoform. The continued conversion of PrPC to PrPSC requires de novo endogenous PrP synthesis for disease progression. The human prion protein gene (PRNP) promoter was therefore investigated to identify regulatory elements that could serve as targets for therapeutic intervention. Findings The human prion protein gene (PRNP) promoter from position -1593 to +134 relative to the putative transcriptional start site (+1) was analyzed by transient transfection in HeLa cells. Deletions from the 5' end between positions -1593 and -232 yielded little change in activity. A further 5' deletion at position -90 resulted in a decline in activity to a level of about 30% of the full-length value. DNase I footprinting of the region between positions -259 and +2 identified two adjacent protected domains designated as prpA (-116 to -143) and prpB (-147 to -186). Internal deletions combined with mobility shift electrophoresis and methylation interference assays indicated the presence of sequence specific nuclear factor complexes that bind to the prpA and prpB domains and activate expression from the human PRNP promoter in an additive fashion. Conclusion Results from transient transfection, DNase I footprinting, mobility shift electrophoresis, and methylation interference experiments suggest that two DNase I protected domains designated as prpA and prpB are binding sites for as yet unidentified regulatory factors that independently activate expression from the PRNP promoter.
Collapse
Affiliation(s)
- Michael J Taheny
- Department of Psychiatry and Behavioral Science, State University of New York at Stony Brook, Stony Brook, NY 11794-8101, USA.
| | | | | | | |
Collapse
|
34
|
Scheckhuber CQ, Grief J, Boilan E, Luce K, Debacq-Chainiaux F, Rittmeyer C, Gredilla R, Kolbesen BO, Toussaint O, Osiewacz HD. Age-related cellular copper dynamics in the fungal ageing model Podospora anserina and in ageing human fibroblasts. PLoS One 2009; 4:e4919. [PMID: 19305496 PMCID: PMC2654708 DOI: 10.1371/journal.pone.0004919] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Accepted: 02/11/2009] [Indexed: 12/14/2022] Open
Abstract
In previous investigations an impact of cellular copper homeostasis on ageing of the ascomycete Podospora anserina has been demonstrated. Here we provide new data indicating that mitochondria play a major role in this process. Determination of copper in the cytosolic fraction using total reflection X-ray fluorescence spectroscopy analysis and eGfp reporter gene studies indicate an age-related increase of cytosolic copper levels. We show that components of the mitochondrial matrix (i.e. eGFP targeted to mitochondria) become released from the organelle during ageing. Decreasing the accessibility of mitochondrial copper in P. anserina via targeting a copper metallothionein to the mitochondrial matrix was found to result in a switch from a copper-dependent cytochrome-c oxidase to a copper-independent alternative oxidase type of respiration and results in lifespan extension. In addition, we demonstrate that increased copper concentrations in the culture medium lead to the appearance of senescence biomarkers in human diploid fibroblasts (HDFs). Significantly, expression of copper-regulated genes is induced during in vitro ageing in medium devoid of excess copper suggesting that cytosolic copper levels also increase during senescence of HDFs. These data suggest that the identified molecular pathway of age-dependent copper dynamics may not be restricted to P. anserina but may be conserved from lower eukaryotes to humans.
Collapse
Affiliation(s)
- Christian Q. Scheckhuber
- Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Jürgen Grief
- Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Emmanuelle Boilan
- Research Unit on Cellular Biology, University of Namur, Namur, Belgium
| | - Karin Luce
- Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | | | - Claudia Rittmeyer
- Institute of Inorganic Chemistry/Analytical Chemistry, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Ricardo Gredilla
- Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Bernd O. Kolbesen
- Institute of Inorganic Chemistry/Analytical Chemistry, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Olivier Toussaint
- Research Unit on Cellular Biology, University of Namur, Namur, Belgium
| | - Heinz D. Osiewacz
- Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| |
Collapse
|
35
|
Abstract
Neurodegenerative diseases remain perplexing and problematic for modern research. Those associated with amyloidogenic proteins have often been lumped together simply because those proteins aggregate. However, research has identified a more logical reason to group some of these diseases together. The associated proteins not only aggregate, but also bind copper. The APP (amyloid precursor protein) binds copper in an N-terminal region. Binding of copper has been suggested to influence generation of beta-amyloid from the protein. PrP (prion protein) binds copper, and this appears to be necessary for its normal function and might also reduce its probability of conversion into an infectious prion. alpha-Synuclein, a protein associated with Parkinson's disease, also binds copper, but, in this case, it potentially increases the rate at which the protein aggregates. The similarities between these proteins, in terms of metal binding, has allowed us to investigate them using similar approaches. In the present review, we discuss some of these approaches.
Collapse
|
36
|
Qin K, Zhao L, Ash RD, McDonough WF, Zhao RY. ATM-mediated Transcriptional Elevation of Prion in Response to Copper-induced Oxidative Stress. J Biol Chem 2009; 284:4582-93. [DOI: 10.1074/jbc.m808410200] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
37
|
Bellingham SA, Coleman LA, Masters CL, Camakaris J, Hill AF. Regulation of prion gene expression by transcription factors SP1 and metal transcription factor-1. J Biol Chem 2009; 284:1291-301. [PMID: 18990686 DOI: 10.1074/jbc.m804755200] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Prion diseases are associated with the conformational conversion of the host-encoded cellular prion protein into an abnormal pathogenic isoform. Reduction in prion protein levels has potential as a therapeutic approach in treating these diseases. Key targets for this goal are factors that affect the regulation of the prion protein gene. Recent in vivo and in vitro studies have suggested a role for prion protein in copper homeostasis. Copper can also induce prion gene expression in rat neurons. However, the mechanism involved in this regulation remains to be determined. We hypothesized that transcription factors SP1 and metal transcription factor-1 (MTF-1) may be involved in copper-mediated regulation of human prion gene. To test the hypothesis, we utilized human fibroblasts that are deleted or overexpressing the Menkes protein (MNK), a major mammalian copper efflux protein. Menkes deletion fibroblasts have high intracellular copper, whereas Menkes overexpressed fibroblasts have severely depleted intracellular copper. We have utilized this system previously to demonstrate copper-dependent regulation of the Alzheimer amyloid precursor protein. Here we demonstrate that copper depletion in MNK overexpressed fibroblasts decreases cellular prion protein and PRNP gene levels. Conversely, expression of transcription factors SP1 and/or MTF-1 significantly increases prion protein levels and up-regulates prion gene expression in copper-replete MNK deletion cells. Furthermore, siRNA "knockdown" of SP1 or MTF-1 in MNK deletion cells decreases prion protein levels and down-regulates prion gene expression. These data support a novel mechanism whereby SP1 and MTF-1 act as copper-sensing transcriptional activators to regulate human prion gene expression and further support a role for the prion protein to function in copper homeostasis. Expression of the prion protein is a vital component for the propagation of prion diseases; thus SP1 and MTF-1 represent new targets in the development of key therapeutics toward modulating the expression of the cellular prion protein and ultimately the prevention of prion disease.
Collapse
Affiliation(s)
- Shayne A Bellingham
- Department of Biochemistry & Molecular Biology, The University of Melbourne, Victoria, Australia
| | | | | | | | | |
Collapse
|
38
|
Inclusion Body Myositis: A View from the Caenorhabditis elegans Muscle. Mol Neurobiol 2008; 38:178-98. [DOI: 10.1007/s12035-008-8041-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Accepted: 08/16/2008] [Indexed: 01/09/2023]
|
39
|
González M, Reyes-Jara A, Suazo M, Jo WJ, Vulpe C. Expression of copper-related genes in response to copper load. Am J Clin Nutr 2008; 88:830S-4S. [PMID: 18779303 DOI: 10.1093/ajcn/88.3.830s] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Copper is an essential micronutrient for all biological systems. Multiple proteins require one or more atoms of copper for proper structure and function, but excess of copper is toxic. To prevent the consequences of copper deficiency and overload, living organisms have evolved molecular mechanisms that regulate its uptake, intracellular traffic, storage, and efflux. Underlying some of the cellular responses to variations in copper levels are changes in the expression of genes encoding molecular components of copper metabolism. In recent years, genome-scale expression analysis in several eukaryotic models has allowed the identification of copper-responsive genes involved in copper homeostasis. Characterization of the transcriptional changes in response to varying copper levels include both genes directly involved in copper homeostasis and genes involved in different cellular process that, even though they are not directly connected to copper metabolism, change their expression during the cellular adaptation to copper availability. Evaluation of these gene expression patterns could aid in the identification of biologically relevant markers to monitor copper status in humans.
Collapse
Affiliation(s)
- Mauricio González
- Instituto de Nutrición y Tecnología de Alimentos, Universidad de Chile, Santiago, Chile.
| | | | | | | | | |
Collapse
|
40
|
Linden R, Martins VR, Prado MAM, Cammarota M, Izquierdo I, Brentani RR. Physiology of the prion protein. Physiol Rev 2008; 88:673-728. [PMID: 18391177 DOI: 10.1152/physrev.00007.2007] [Citation(s) in RCA: 435] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Prion diseases are transmissible spongiform encephalopathies (TSEs), attributed to conformational conversion of the cellular prion protein (PrP(C)) into an abnormal conformer that accumulates in the brain. Understanding the pathogenesis of TSEs requires the identification of functional properties of PrP(C). Here we examine the physiological functions of PrP(C) at the systemic, cellular, and molecular level. Current data show that both the expression and the engagement of PrP(C) with a variety of ligands modulate the following: 1) functions of the nervous and immune systems, including memory and inflammatory reactions; 2) cell proliferation, differentiation, and sensitivity to programmed cell death both in the nervous and immune systems, as well as in various cell lines; 3) the activity of numerous signal transduction pathways, including cAMP/protein kinase A, mitogen-activated protein kinase, phosphatidylinositol 3-kinase/Akt pathways, as well as soluble non-receptor tyrosine kinases; and 4) trafficking of PrP(C) both laterally among distinct plasma membrane domains, and along endocytic pathways, on top of continuous, rapid recycling. A unified view of these functional properties indicates that the prion protein is a dynamic cell surface platform for the assembly of signaling modules, based on which selective interactions with many ligands and transmembrane signaling pathways translate into wide-range consequences upon both physiology and behavior.
Collapse
Affiliation(s)
- Rafael Linden
- Instituto de Biofísica da Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | | | | | | | | | | |
Collapse
|
41
|
Rezaie P, Al-Sarraj S. Vacuolar degeneration affecting brain macrophages/microglia in variant CJD: a report on two cases. Acta Neuropathol 2007; 114:651-8. [PMID: 17943296 DOI: 10.1007/s00401-007-0294-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2007] [Revised: 09/10/2007] [Accepted: 09/10/2007] [Indexed: 12/25/2022]
Abstract
We present the neuropathology of two cases of variant Creutzfeldt-Jakob disease (vCJD) showing significant vacuolar degenerative alterations specifically affecting brain macrophages/microglia within the thalamus and, to a lesser extent, within the neocortical grey matter. Vacuolar degeneration in these cells was extensive, and likely to be associated with the development of a uniform sub-type of 'spongiform' vacuole seen in vCJD. The extensive morphological alterations described here closely resemble those very recently reported by Zucconi and colleagues, in response to experimental copper deficiency induced through dietary restriction, but could not be detected in cases of sporadic CJD examined. The significance of these novel findings are discussed in relation to copper homeostasis, loss of function of cellular prion protein and aberrant lysosomal catabolism within brain macrophages/microglia. This type of vacuolation may constitute a component of the overall profile of spongiform changes associated with vCJD.
Collapse
Affiliation(s)
- Payam Rezaie
- Department of Biological Sciences, Faculty of Science, The Open University, Milton Keynes, MK7 6AA, UK.
| | | |
Collapse
|
42
|
Irons RD, Le AT. Dithiocarbamates and viral IL-10 collaborate in the immortalization and evasion of immune response in EBV-infected human B lymphocytes. Chem Biol Interact 2007; 172:81-92. [PMID: 18163983 DOI: 10.1016/j.cbi.2007.11.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 11/12/2007] [Accepted: 11/14/2007] [Indexed: 10/22/2022]
Abstract
Epstein-Barr virus (EBV) is implicated in the development of a number of human malignancies including several subtypes of non-Hodgkin lymphoma (NHL) [G. Pallesen, S.J. Hamilton-Dutoit, X. Zhou, The association of Epstein-Barr virus (EBV) with T cell lymphoproliferations and Hodgkin's disease: two new developments in the EBV Field, Adv. Cancer Res. 62 (1993) 179-239]. Lymphoproliferative disease and NHL occurring in severely immunosuppressed individuals almost always involve EBV and have been extensively studied and modeled in vitro. EBV has also been causally associated with some cases of NHL occurring in otherwise immunocompetent individuals. However, a direct role for EBV in the pathogenesis of neoplasms developing in the presence of an otherwise competent immune system has not been established. We investigated potential interactions between dithiocarbamates (DTC), an important class of thiono-sulfur compounds, and EBV leading to immortalization of human B lymphocytes and evasion of cell-mediated immune response in culture. Primary lymphocyte cultures employing wild-type and recombinant EBV mutants were used to assess the respective roles of DTC and viral genes in lymphocyte transformation and survival. Pretreatment of EBV-infected human B lymphocytes with DTC directly enhanced transformation in the absence of T cells (5 nM) and independently increased survival of transformed cells in the presence of competent autologous T cells (10 nM). Both DTC-induced transformation and immortalization of EBV-infected B lymphocytes were dependent on the expression of viral IL-10. These results provide a biological basis for studying collaborations between chemical and virus that alter lymphocyte biology, and provide a rationale for further molecular epidemiology studies to better understand the potential influence of these interactions on the development of NHL and perhaps other viral-associated malignancies.
Collapse
Affiliation(s)
- Richard D Irons
- Fudan-Cinpathogen Clinical and Molecular Research Center, Institutes of Biomedical Sciences and Department of Pathology, Fudan University, Shanghai, China.
| | | |
Collapse
|
43
|
Schmidt I, Fähling M, Nafz B, Skalweit A, Thiele BJ. Induction of translationally controlled tumor protein (TCTP) by transcriptional and post-transcriptional mechanisms. FEBS J 2007; 274:5416-24. [PMID: 17894822 DOI: 10.1111/j.1742-4658.2007.06069.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Expression of the human TPT1 gene coding for translationally controlled tumor protein (TCTP) was investigated in Calu-6 and Cos-7 cells under the influence of 4beta-phorbol 12-myristate 13-acetate (PMA), forskolin, dioxin and the heavy metals copper, nickel and cobalt. Transcriptional and post-transcriptional aspects of the mechanism were analyzed by TCTP mRNA/protein quantification, luciferase reporter gene assays depending on TPT1 promoter sequences or TCTP mRNA 5'/3'-UTRs and investigation of the interaction of RNA-binding proteins with UTRs by UV-crosslinking. PMA, forskolin, dioxin, cobalt and nickel induced TCTP expression in 24 h in both cell lines about 2.2-3.2-fold at the mRNA level and 1.6-2.2-fold at the protein level. The highest induction rate, 4.5-5.0-fold at the mRNA level and 3.5-4.0-fold at the protein level, was observed with copper. TPT1 promoter assays showed transcriptional activation by PMA, forskolin and dioxin (2.0-3.1-fold) and a 7.0-8.0-fold increase by copper, whereas cobalt and nickel had no effect. Deletion analysis revealed that copper-dependent transcriptional control was transmitted by a metal-responsive element residing in the TPT1 promoter. Post-transcriptional activation of TCTP expression was associated with the action of dioxin, nickel, cobalt (1.8-2.3-fold) and copper (2.5-3.0-fold), whereas stimulation of TCTP synthesis by copper was mediated by the TCTP mRNA 3'-UTR (3.2-fold) but not by the 5'-UTR (0.5-fold). mRNA stabilization was found to mediate these effects of cobalt and nickel. Post-transcriptional regulation was associated with qualitative and quantitative changes in the binding of specific RNA-binding proteins to UTRs.
Collapse
Affiliation(s)
- Irina Schmidt
- Charité, Universitätsmedizin Berlin, Institut für Vegetative Physiologie, Germany
| | | | | | | | | |
Collapse
|
44
|
Suazo M, Olivares F, Mendez MA, Pulgar R, Prohaska JR, Arredondo M, Pizarro F, Olivares M, Araya M, González M. CCS and SOD1 mRNA are reduced after copper supplementation in peripheral mononuclear cells of individuals with high serum ceruloplasmin concentration. J Nutr Biochem 2007; 19:269-74. [PMID: 17683925 DOI: 10.1016/j.jnutbio.2007.04.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Revised: 04/11/2007] [Accepted: 04/20/2007] [Indexed: 11/16/2022]
Abstract
The limits of copper homeostatic regulation in humans are not known, making it difficult to define the milder effects of early copper excess. Furthermore, a robust assay to facilitate the detection of early stages of copper excess is needed. To address these issues, we assessed changes in relative mRNA abundance of methallothionein 2A (MT2A), prion (PrP), amyloid precursor-like protein 2 (APLP2), Cu/Zn superoxide dismutase (SOD1) and its copper chaperone (CCS) in peripheral mononuclear cells (PMNCs) from healthy adults representing the 5% highest and lowest extremes in the distribution curve of serum ceruloplasmin (Cp) concentrations of 800 individuals. The intracellular Cu content was also determined. PMNCs were isolated from individuals before and after exposure to a single daily dose of 10 mg Cu (as CuSO(4)) for 2 months. Results showed that although there were fluctuations in serum Cp values of the samples assessed before copper exposure, no significant differences were observed in cell copper content or in the relative abundance of MT2A, PrP and APLP2 transcripts in PMNCs. Also, these values were not modified after copper supplementation. However, CCS and SOD1 mRNA levels were reduced in PMNCs after copper supplementation in the individuals with the high Cp values, suggesting that they should be further explored as biomarkers of moderate copper overload in humans.
Collapse
Affiliation(s)
- Miriam Suazo
- Laboratory of Micronutrients, University of Chile (INTA), Santiago, Chile
| | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Donadio S, Alfaidy N, De Keukeleire B, Micoud J, Feige JJ, Challis JRG, Benharouga M. Expression and Localization of Cellular Prion and COMMD1 Proteins in Human Placenta throughout Pregnancy. Placenta 2007; 28:907-11. [PMID: 17254632 DOI: 10.1016/j.placenta.2006.11.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2006] [Revised: 11/20/2006] [Accepted: 11/21/2006] [Indexed: 11/30/2022]
Abstract
Copper is an essential trace element for successful pregnancy. However, the mechanisms by which copper is transported from maternal circulation to the fetus have not been clearly elucidated. Two proteins, cellular prion (PrP(C)) and COMMD1, are known to be responsible for prion diseases and canine copper toxicosis, respectively, and are thought to play a role in copper homeostasis. However, their placental expression and localization throughout human gestation are still unknown. In this study, we used quantitative RT-PCR, western blotting and immunohistochemistry to investigate in detail the expression and localization of PrP(C) and COMMD1 proteins in human placenta throughout pregnancy. Our results show that both proteins are expressed in human placenta. PrP(C) showed the highest mRNA and protein expression levels during the first trimester of pregnancy. PrP(C) and COMMD1 proteins are similarly localized within the placental villi. Both proteins are present in the syncytiotrophoblast, the cytotrophoblast, vascular endothelial cells and Hofbauer cells. These data offer some insights into possible roles for PrP(C) and COMMD1 within the placenta.
Collapse
Affiliation(s)
- S Donadio
- CEA Grenoble, UMR 5090 CEA/CNRS/Université Joseph Fourier, Département Réponse et Dynamique Cellulaire, Laboratoire de Biophysique Moléculaire et Cellulaire, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | | | | | | | | | | | | |
Collapse
|
46
|
Healy J, Tipton K. Ceruloplasmin and what it might do. J Neural Transm (Vienna) 2007; 114:777-81. [PMID: 17406962 DOI: 10.1007/s00702-007-0687-7] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2006] [Accepted: 11/22/2006] [Indexed: 01/15/2023]
Abstract
The blue coloured plasma protein ceruloplasmin binds up to 95% of circulating copper, and has several possible functions. It has been proposed to function in copper transport, oxidation of organic amines, iron(II) oxidation and the regulation of cellular iron levels, and catechols, radical scavenging and other antioxidant processes. This account will consider the relative importance of these multiple functions in terms of the physiological roles of ceruloplasmin.
Collapse
Affiliation(s)
- J Healy
- Department of Biochemistry, School of Biochemistry and Immunology, Trinity College, Dublin, Ireland.
| | | |
Collapse
|
47
|
Ferrada E, Arancibia V, Loeb B, Norambuena E, Olea-Azar C, Huidobro-Toro JP. Stoichiometry and conditional stability constants of Cu(II) or Zn(II) clioquinol complexes; implications for Alzheimer's and Huntington's disease therapy. Neurotoxicology 2007; 28:445-9. [PMID: 17382398 DOI: 10.1016/j.neuro.2007.02.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2006] [Revised: 02/04/2007] [Accepted: 02/05/2007] [Indexed: 11/21/2022]
Abstract
Successful trials with 5-chloro-7-iodo-8-hydroxyquinoline (clioquinol, CQ) for Alzheimer's disease treatment prompted renewed interest in assessing whether its therapeutic action is related to the coordination of neurotoxic trace metals, such as Cu(II) and Zn(II). We now report conditional stability constants (K(C')) for CQ Cu(II) and Zn(II) complexes measured in a biological buffer containing Ca(II) and Mg(II) ions. UV-vis spectroscopy and polarography evidenced a 1:2 stoichiometry of Cu(II) and Zn(II) CQ complexes; the K(C')s calculated were: Cu(CQ)(2) 1.2x10(10), and Zn(CQ)(2) 7.0x10(8)M(-2); the CQ affinity for Cu(II) is at least an order of magnitude higher than for Zn(II). To test the possible functional relevance of the Cu(II) CQ complexes in the brain, we bioassayed free Cu(II) concentration by the metal-induced inhibition of ATP-gated currents of the P2X(4) receptor, a predominant brain P2X receptor. CQ reduced concentration-dependently the Cu(II) inhibition of the ATP-gated currents. In view that the stability constant of CQ for Zn(II) is similar to that of Abeta-amyloid for Zn(II), and the fact that CQ may form complexes with Cu(II), even in the presence of competing ions, the present results highlight that the formation of Cu(II) CQ complexes in the brain may act by diminishing free Cu(II) concentrations modifying thereby brain excitability, or favoring the degradation of beta-amyloid plaques or huntingtin, rather than through a specific effect of CQ itself.
Collapse
Affiliation(s)
- Evandro Ferrada
- Centro de Regulación Celular y Patología, Prof. J.V. Luco e Instituto Milenio de Biología Fundamental y Aplicada, MIFAB, Departamento Fisiología, Facultad de Ciencias Biológicas y, Santiago, Chile.
| | | | | | | | | | | |
Collapse
|
48
|
Huster D, Lutsenko S. Wilson disease: not just a copper disorder. Analysis of a Wilson disease model demonstrates the link between copper and lipid metabolism. MOLECULAR BIOSYSTEMS 2007; 3:816-24. [DOI: 10.1039/b711118p] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
49
|
Choi CJ, Kanthasamy A, Anantharam V, Kanthasamy AG. Interaction of metals with prion protein: Possible role of divalent cations in the pathogenesis of prion diseases. Neurotoxicology 2006; 27:777-87. [PMID: 16860868 DOI: 10.1016/j.neuro.2006.06.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2006] [Revised: 06/03/2006] [Accepted: 06/03/2006] [Indexed: 01/29/2023]
Abstract
Prion diseases are fatal neurodegenerative disorders that affect both humans and animals. The rapid clinical progression, change in protein conformation, cross-species transmission and massive neuronal degeneration are some key features of this devastating degenerative condition. Although the etiology is unknown, aberrant processing of cellular prion proteins is well established in the pathogenesis of prion diseases. Normal cellular prion protein (PrP(c)) is highly conserved in mammals and expressed predominantly in the brain. Nevertheless, the exact function of the normal prion protein in the CNS has not been fully elucidated. Prion proteins may function as a metal binding protein because divalent cations such as copper, zinc and manganese can bind to octapeptide repeat sequences in the N-terminus of PrP(c). Since the binding of these metals to the octapeptide has been proposed to influence both structural and functional properties of prion proteins, alterations in transition metal levels can alter the course of the disease. Furthermore, cellular antioxidant capacity is significantly compromised due to conversion of the normal prion protein (PrP(c)) to an abnormal scrapie prion (PrP(sc)) protein, suggesting that oxidative stress may play a role in the neurodegenerative process of prion diseases. The combination of imbalances in cellular transition metals and increased oxidative stress could further exacerbate the neurotoxic effect of PrP(sc). This review includes an overview of the structure and function of prion proteins, followed by the role of metals such as copper, manganese and iron in the physiological function of the PrP(c), and the possible role of transition metals in the pathogenesis of the prion disease.
Collapse
Affiliation(s)
- Christopher J Choi
- Parkinson's Disorder Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, Iowa State University, 2062 Veterinary Medicine Building, Ames, IA 50011-1250, USA
| | | | | | | |
Collapse
|