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Karner D, Kvestak D, Kucan Brlic P, Cokaric Brdovcak M, Lisnic B, Brizic I, Juranic Lisnic V, Golemac M, Tomac J, Krmpotic A, Karkeni E, Libri V, Mella S, Legname G, Altmeppen HC, Hasan M, Jonjic S, Lenac Rovis T. Prion protein alters viral control and enhances pathology after perinatal cytomegalovirus infection. Nat Commun 2024; 15:7754. [PMID: 39237588 PMCID: PMC11377837 DOI: 10.1038/s41467-024-51931-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 08/20/2024] [Indexed: 09/07/2024] Open
Abstract
Cytomegalovirus (CMV) infection poses risks to newborns, necessitating effective therapies. Given that the damage includes both viral infection of brain cells and immune system-related damage, here we investigate the involvement of cellular prion protein (PrP), which plays vital roles in neuroprotection and immune regulation. Using a murine model, we show the role of PrP in tempering neonatal T cell immunity during CMV infection. PrP-null mice exhibit enhanced viral control through elevated virus-specific CD8 T cell responses, leading to reduced viral titers and pathology. We further unravel the molecular mechanisms by showing CMV-induced upregulation followed by release of PrP via the metalloproteinase ADAM10, impairing CD8 T cell response specifically in neonates. Additionally, we confirm PrP downregulation in human CMV (HCMV)-infected fibroblasts, underscoring the broader relevance of our observations beyond the murine model. Furthermore, our study highlights how PrP, under the stress of viral pathogenesis, reveals its impact on neonatal immune modulation.
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Affiliation(s)
- Dubravka Karner
- Center for Proteomics; Faculty of Medicine; University of Rijeka, Rijeka, Croatia
| | - Daria Kvestak
- Center for Proteomics; Faculty of Medicine; University of Rijeka, Rijeka, Croatia
| | - Paola Kucan Brlic
- Center for Proteomics; Faculty of Medicine; University of Rijeka, Rijeka, Croatia
| | | | - Berislav Lisnic
- Center for Proteomics; Faculty of Medicine; University of Rijeka, Rijeka, Croatia
| | - Ilija Brizic
- Center for Proteomics; Faculty of Medicine; University of Rijeka, Rijeka, Croatia
| | - Vanda Juranic Lisnic
- Center for Proteomics; Faculty of Medicine; University of Rijeka, Rijeka, Croatia
| | - Mijo Golemac
- Department of Histology and Embryology; Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Jelena Tomac
- Department of Histology and Embryology; Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Astrid Krmpotic
- Department of Histology and Embryology; Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Esma Karkeni
- Cytometry and Biomarkers Unit of Technology and Service (CB TechS); Institut Pasteur, Université Paris Cité, Paris, France
| | - Valentina Libri
- Cytometry and Biomarkers Unit of Technology and Service (CB TechS); Institut Pasteur, Université Paris Cité, Paris, France
| | - Sebastien Mella
- Cytometry and Biomarkers Unit of Technology and Service (CB TechS); Institut Pasteur, Université Paris Cité, Paris, France
| | - Giuseppe Legname
- Department of Neuroscience, Prion Biology Laboratory, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
| | - Hermann C Altmeppen
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Milena Hasan
- Cytometry and Biomarkers Unit of Technology and Service (CB TechS); Institut Pasteur, Université Paris Cité, Paris, France
| | - Stipan Jonjic
- Center for Proteomics; Faculty of Medicine; University of Rijeka, Rijeka, Croatia
| | - Tihana Lenac Rovis
- Center for Proteomics; Faculty of Medicine; University of Rijeka, Rijeka, Croatia.
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2
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Bizingre C, Bianchi C, Baudry A, Alleaume-Butaux A, Schneider B, Pietri M. Post-translational modifications in prion diseases. Front Mol Neurosci 2024; 17:1405415. [PMID: 39011540 PMCID: PMC11247024 DOI: 10.3389/fnmol.2024.1405415] [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: 03/22/2024] [Accepted: 06/14/2024] [Indexed: 07/17/2024] Open
Abstract
More than 650 reversible and irreversible post-translational modifications (PTMs) of proteins have been listed so far. Canonical PTMs of proteins consist of the covalent addition of functional or chemical groups on target backbone amino-acids or the cleavage of the protein itself, giving rise to modified proteins with specific properties in terms of stability, solubility, cell distribution, activity, or interactions with other biomolecules. PTMs of protein contribute to cell homeostatic processes, enabling basal cell functions, allowing the cell to respond and adapt to variations of its environment, and globally maintaining the constancy of the milieu interieur (the body's inner environment) to sustain human health. Abnormal protein PTMs are, however, associated with several disease states, such as cancers, metabolic disorders, or neurodegenerative diseases. Abnormal PTMs alter the functional properties of the protein or even cause a loss of protein function. One example of dramatic PTMs concerns the cellular prion protein (PrPC), a GPI-anchored signaling molecule at the plasma membrane, whose irreversible post-translational conformational conversion (PTCC) into pathogenic prions (PrPSc) provokes neurodegeneration. PrPC PTCC into PrPSc is an additional type of PTM that affects the tridimensional structure and physiological function of PrPC and generates a protein conformer with neurotoxic properties. PrPC PTCC into PrPSc in neurons is the first step of a deleterious sequence of events at the root of a group of neurodegenerative disorders affecting both humans (Creutzfeldt-Jakob diseases for the most representative diseases) and animals (scrapie in sheep, bovine spongiform encephalopathy in cow, and chronic wasting disease in elk and deer). There are currently no therapies to block PrPC PTCC into PrPSc and stop neurodegeneration in prion diseases. Here, we review known PrPC PTMs that influence PrPC conversion into PrPSc. We summarized how PrPC PTCC into PrPSc impacts the PrPC interactome at the plasma membrane and the downstream intracellular controlled protein effectors, whose abnormal activation or trafficking caused by altered PTMs promotes neurodegeneration. We discussed these effectors as candidate drug targets for prion diseases and possibly other neurodegenerative diseases.
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Affiliation(s)
- Chloé Bizingre
- INSERM UMR-S 1124, Paris, France
- Université Paris Cité, UMR-S 1124, Paris, France
| | - Clara Bianchi
- INSERM UMR-S 1124, Paris, France
- Université Paris Cité, UMR-S 1124, Paris, France
| | - Anne Baudry
- INSERM UMR-S 1124, Paris, France
- Université Paris Cité, UMR-S 1124, Paris, France
| | | | - Benoit Schneider
- INSERM UMR-S 1124, Paris, France
- Université Paris Cité, UMR-S 1124, Paris, France
- Ecole polytechnique, Institut Polytechnique de Paris, CNRS UMR7654, Palaiseau, France
| | - Mathéa Pietri
- INSERM UMR-S 1124, Paris, France
- Université Paris Cité, UMR-S 1124, Paris, France
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3
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Cha S, Kim MY. The role of cellular prion protein in immune system. BMB Rep 2023; 56:645-650. [PMID: 37817440 PMCID: PMC10761747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/13/2023] [Accepted: 09/25/2023] [Indexed: 10/12/2023] Open
Abstract
Numerous studies have investigated the cellular prion protein (PrPC) since its discovery. These investigations have explained that its structure is predominantly composed of alpha helices and short beta sheet segments, and when its abnormal scrapie isoform (PrPSc) is infected, PrPSc transforms the PrPC, leading to prion diseases, including Creutzfeldt-Jakob disease in humans and bovine spongiform encephalopathy in cattle. Given its ubiquitous distribution across a variety of cellular types, the PrPC manifests a diverse range of biological functions, including cell-cell adhesion, neuroprotection, signalings, and oxidative stress response. PrPC is also expressed in immune tissues, and its functions in these tissues include the activation of immune cells and the formation of secondary lymphoid tissues, such as the spleen and lymph nodes. Moreover, high expression of PrPC in immune cells plays a crucial role in the pathogenesis of prion diseases. In addition, it affects inflammation and the development and progression of cancer via various mechanisms. In this review, we discuss the studies on the role of PrPC from various immunological perspectives. [BMB Reports 2023; 56(12): 645-650].
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Affiliation(s)
- Seunghwa Cha
- Department of Bioinformatics and Life Science, Soongsil University, Seoul 06978, Korea
| | - Mi-Yeon Kim
- Department of Bioinformatics and Life Science, Soongsil University, Seoul 06978, Korea
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4
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Lindner E, Woltsche N, Merle D, Steinwender G, Strohmaier H, Nairz M, Ivastinovic D. Prion Protein on Human Leukocytes Is Reduced in Iron Deficiency - Possible Implications for Age-related Macular Degeneration? Curr Eye Res 2020; 46:1178-1183. [PMID: 33317353 DOI: 10.1080/02713683.2020.1863432] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
MATERIALS AND METHODS Patients presenting to the department of ophthalmology of the Medical University of Graz for reasons unrelated to prion diseases were enrolled. Parameters of iron metabolism, including ferritin and soluble transferrin receptor were measured by routine laboratory tests. Serum prion protein was determined by enzyme-linked immunosorbent assay. Surface prion protein on CD14+ monocytes and CD4+ T cells was analyzed by fluorescence activated cell sorting. RESULTS 95 patients were enrolled. Soluble transferrin receptor correlated significantly with prion protein levels on CD14+POM1+ monocytes (P = .001, r = -0.7) and on CD4+POM1+ T cells (P = .01, r = -0.62). CONCLUSION Our findings suggest a connection between the physiological function of the prion protein and iron metabolism in humans.
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Affiliation(s)
- Ewald Lindner
- Department of Ophthalmology, Medical University Graz, Graz, Austria
| | - Nora Woltsche
- Department of Ophthalmology, Medical University Graz, Graz, Austria
| | - David Merle
- Department of Ophthalmology, Medical University Graz, Graz, Austria
| | | | - Heimo Strohmaier
- Core Facility Imaging, Centre of Medical Research Graz, Graz, Austria
| | - Manfred Nairz
- Department of General Internal Medicine, Medical University Innsbruck, Innsbruck, Austria
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Salvesen Ø, Tatzelt J, Tranulis MA. The prion protein in neuroimmune crosstalk. Neurochem Int 2018; 130:104335. [PMID: 30448564 DOI: 10.1016/j.neuint.2018.11.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 10/04/2018] [Accepted: 11/14/2018] [Indexed: 01/11/2023]
Abstract
The cellular prion protein (PrPC) is a medium-sized glycoprotein, attached to the cell surface by a glycosylphosphatidylinositol anchor. PrPC is encoded by a single-copy gene, PRNP, which is abundantly expressed in the central nervous system and at lower levels in non-neuronal cells, including those of the immune system. Evidence from experimental knockout of PRNP in rodents, goats, and cattle and the occurrence of a nonsense mutation in goat that prevents synthesis of PrPC, have shown that the molecule is non-essential for life. Indeed, no easily recognizable phenotypes are associate with a lack of PrPC, except the potentially advantageous trait that animals without PrPC cannot develop prion disease. This is because, in prion diseases, PrPC converts to a pathogenic "scrapie" conformer, PrPSc, which aggregates and eventually induces neurodegeneration. In addition, endogenous neuronal PrPC serves as a toxic receptor to mediate prion-induced neurotoxicity. Thus, PrPC is an interesting target for treatment of prion diseases. Although loss of PrPC has no discernable effect, alteration of its normal physiological function can have very harmful consequences. It is therefore important to understand cellular processes involving PrPC, and research of this topic has advanced considerably in the past decade. Here, we summarize data that indicate the role of PrPC in modulating immune signaling, with emphasis on neuroimmune crosstalk both under basal conditions and during inflammatory stress.
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Affiliation(s)
- Øyvind Salvesen
- Faculty of Veterinary Medicine, Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, Sandnes, Norway.
| | - Jörg Tatzelt
- Department Biochemistry of Neurodegenerative Diseases, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Germany.
| | - Michael A Tranulis
- Faculty of Veterinary Medicine, Department of Basic Sciences and Aquatic Medicine, Norwegian University of Life Sciences, Oslo, Norway.
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6
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Megra BW, Eugenin EA, Berman JW. The Role of Shed PrP c in the Neuropathogenesis of HIV Infection. THE JOURNAL OF IMMUNOLOGY 2017; 199:224-232. [PMID: 28533442 DOI: 10.4049/jimmunol.1601041] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 04/21/2017] [Indexed: 01/02/2023]
Abstract
HIV-1 enters the CNS soon after peripheral infection and causes chronic neuroinflammation and neuronal damage that leads to cognitive impairment in 40-70% of HIV-infected people. The nonpathogenic cellular isoform of the human prion protein (PrPc) is an adhesion molecule constitutively expressed in the CNS. Previously, our laboratory showed that shed PrPc (sPrPc) is increased in the cerebrospinal fluid of HIV-infected people with cognitive deficits as compared with infected people with no impairment. In this article, we demonstrate that CCL2 and TNF-α, inflammatory mediators that are elevated in the CNS of HIV-infected people, increase shedding of PrPc from human astrocytes by increasing the active form of the metalloprotease ADAM10. We show that the consequence of this shedding can be the production of inflammatory mediators, because treatment of astrocytes with rPrPc increased secretion of CCL2, CXCL-12, and IL-8. Supernatants from rPrPc-treated astrocytes containing factors produced in response to this treatment, but not rPrPc by itself, cause increased chemotaxis of both uninfected and HIV-infected human monocytes, suggesting a role for sPrPc in monocyte recruitment into the brain. Furthermore, we examined whether PrPc participates in glutamate uptake and found that rPrPc decreased uptake of this metabolite in astrocytes, which could lead to neurotoxicity and neuronal loss. Collectively, our data characterize mediators involved in PrPc shedding and the effect of this sPrPc on monocyte chemotaxis and glutamate uptake from astrocytes. We propose that shedding of PrPc could be a potential target for therapeutics to limit the cognitive impairment characteristic of neuroAIDS.
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Affiliation(s)
- Bezawit W Megra
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Eliseo A Eugenin
- Public Health Research Institute, 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, Albert Einstein College of Medicine, Bronx, NY 10461; and.,Department of Immunology, Albert Einstein College of Medicine, Bronx, NY 10461
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7
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Linden R. The Biological Function of the Prion Protein: A Cell Surface Scaffold of Signaling Modules. Front Mol Neurosci 2017; 10:77. [PMID: 28373833 PMCID: PMC5357658 DOI: 10.3389/fnmol.2017.00077] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 03/06/2017] [Indexed: 12/18/2022] Open
Abstract
The prion glycoprotein (PrPC) is mostly located at the cell surface, tethered to the plasma membrane through a glycosyl-phosphatydil inositol (GPI) anchor. Misfolding of PrPC is associated with the transmissible spongiform encephalopathies (TSEs), whereas its normal conformer serves as a receptor for oligomers of the β-amyloid peptide, which play a major role in the pathogenesis of Alzheimer’s Disease (AD). PrPC is highly expressed in both the nervous and immune systems, as well as in other organs, but its functions are controversial. Extensive experimental work disclosed multiple physiological roles of PrPC at the molecular, cellular and systemic levels, affecting the homeostasis of copper, neuroprotection, stem cell renewal and memory mechanisms, among others. Often each such process has been heralded as the bona fide function of PrPC, despite restricted attention paid to a selected phenotypic trait, associated with either modulation of gene expression or to the engagement of PrPC with a single ligand. In contrast, the GPI-anchored prion protein was shown to bind several extracellular and transmembrane ligands, which are required to endow that protein with the ability to play various roles in transmembrane signal transduction. In addition, differing sets of those ligands are available in cell type- and context-dependent scenarios. To account for such properties, we proposed that PrPC serves as a dynamic platform for the assembly of signaling modules at the cell surface, with widespread consequences for both physiology and behavior. The current review advances the hypothesis that the biological function of the prion protein is that of a cell surface scaffold protein, based on the striking similarities of its functional properties with those of scaffold proteins involved in the organization of intracellular signal transduction pathways. Those properties are: the ability to recruit spatially restricted sets of binding molecules involved in specific signaling; mediation of the crosstalk of signaling pathways; reciprocal allosteric regulation with binding partners; compartmentalized responses; dependence of signaling properties upon posttranslational modification; and stoichiometric requirements and/or oligomerization-dependent impact on signaling. The scaffold concept may contribute to novel approaches to the development of effective treatments to hitherto incurable neurodegenerative diseases, through informed modulation of prion protein-ligand interactions.
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Affiliation(s)
- Rafael Linden
- Laboratory of Neurogenesis, Institute of Biophysics, Federal University of Rio de Janeiro Rio de Janeiro, Brazil
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8
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Kim HJ, Choi HS, Park JH, Kim MJ, Lee HG, Petersen RB, Kim YS, Park JB, Choi EK. Regulation of RhoA activity by the cellular prion protein. Cell Death Dis 2017; 8:e2668. [PMID: 28300846 PMCID: PMC5386549 DOI: 10.1038/cddis.2017.37] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 12/18/2016] [Accepted: 01/10/2017] [Indexed: 01/28/2023]
Abstract
The cellular prion protein (PrPC) is a highly conserved glycosylphosphatidylinositol (GPI)-anchored membrane protein that is involved in the signal transduction during the initial phase of neurite outgrowth. The Ras homolog gene family member A (RhoA) is a small GTPase that is known to have an essential role in regulating the development, differentiation, survival, and death of neurons in the central nervous system. Although recent studies have shown the dysregulation of RhoA in a variety of neurodegenerative diseases, the role of RhoA in prion pathogenesis remains unclear. Here, we investigated the regulation of RhoA-mediated signaling by PrPC using both in vitro and in vivo models and found that overexpression of PrPC significantly induced RhoA inactivation and RhoA phosphorylation in hippocampal neuronal cells and in the brains of transgenic mice. Using siRNA-mediated depletion of endogenous PrPC and overexpression of disease-associated mutants of PrPC, we confirmed that PrPC induced RhoA inactivation, which accompanied RhoA phosphorylation but reduced the phosphorylation levels of LIM kinase (LIMK), leading to cofilin activation. In addition, PrPC colocalized with RhoA, and the overexpression of PrPC significantly increased neurite outgrowth in nerve growth factor-treated PC12 cells through RhoA inactivation. However, the disease-associated mutants of PrPC decreased neurite outgrowth compared with wild-type PrPC. Moreover, inhibition of Rho-associated kinase (ROCK) substantially facilitated neurite outgrowth in NGF-treated PC12 cells, similar to the effect induced by PrPC. Interestingly, we found that the induction of RhoA inactivation occurred through the interaction of PrPC with RhoA and that PrPC enhanced the interaction between RhoA and p190RhoGAP (a GTPase-activating protein). These findings suggest that the interactions of PrPC with RhoA and p190RhoGAP contribute to neurite outgrowth by controlling RhoA inactivation and RhoA-mediated signaling and that disease-associated mutations of PrPC impair RhoA inactivation, which in turn leads to prion-related neurodegeneration.
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Affiliation(s)
- Hee-Jun Kim
- Ilsong Institute of Life Science, Hallym University, Anyang, Republic of Korea
| | - Hong-Seok Choi
- Ilsong Institute of Life Science, Hallym University, Anyang, Republic of Korea.,Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Jeong-Ho Park
- Ilsong Institute of Life Science, Hallym University, Anyang, Republic of Korea.,Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Mo-Jong Kim
- Ilsong Institute of Life Science, Hallym University, Anyang, Republic of Korea.,Department of Biomedical Gerontology, Graduate School of Hallym University, Chuncheon, Republic of Korea
| | - Hyoung-Gon Lee
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Robert Bob Petersen
- Department of Pathology, Case Western Reserve University, Cleveland, OH, USA.,Departments of Neuroscience and Neurology, Case Western Reserve University, Cleveland, OH, USA
| | - Yong-Sun Kim
- Ilsong Institute of Life Science, Hallym University, Anyang, Republic of Korea.,Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Jae-Bong Park
- Department of Biochemistry, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Eun-Kyoung Choi
- Ilsong Institute of Life Science, Hallym University, Anyang, Republic of Korea.,Department of Biomedical Gerontology, Graduate School of Hallym University, Chuncheon, Republic of Korea
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9
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Reiten MR, Bakkebø MK, Brun-Hansen H, Lewandowska-Sabat AM, Olsaker I, Tranulis MA, Espenes A, Boysen P. Hematological shift in goat kids naturally devoid of prion protein. Front Cell Dev Biol 2015. [PMID: 26217662 PMCID: PMC4495340 DOI: 10.3389/fcell.2015.00044] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The physiological role of the cellular prion protein (PrPC) is incompletely understood. The expression of PrPC in hematopoietic stem cells and immune cells suggests a role in the development of these cells, and in PrPC knockout animals altered immune cell proliferation and phagocytic function have been observed. Recently, a spontaneous nonsense mutation at codon 32 in the PRNP gene in goats of the Norwegian Dairy breed was discovered, rendering homozygous animals devoid of PrPC. Here we report hematological and immunological analyses of homozygous goat kids lacking PrPC (PRNPTer/Ter) compared to heterozygous (PRNP+/Ter) and normal (PRNP+/+) kids. Levels of cell surface PrPC and PRNP mRNA in peripheral blood mononuclear cells (PBMCs) correlated well and were very low in PRNPTer/Ter, intermediate in PRNP+/Ter and high in PRNP+/+ kids. The PRNPTer/Ter animals had a shift in blood cell composition with an elevated number of red blood cells (RBCs) and a tendency toward a smaller mean RBC volume (P = 0.08) and an increased number of neutrophils (P = 0.068), all values within the reference ranges. Morphological investigations of blood smears and bone marrow imprints did not reveal irregularities. Studies of relative composition of PBMCs, phagocytic ability of monocytes and T-cell proliferation revealed no significant differences between the genotypes. Our data suggest that PrPC has a role in bone marrow physiology and warrant further studies of PrPC in erythroid and immune cell progenitors as well as differentiated effector cells also under stressful conditions. Altogether, this genetically unmanipulated PrPC-free animal model represents a unique opportunity to unveil the enigmatic physiology and function of PrPC.
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Affiliation(s)
- Malin R Reiten
- Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences Oslo, Norway
| | - Maren K Bakkebø
- Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences Oslo, Norway
| | - Hege Brun-Hansen
- Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences Oslo, Norway
| | - Anna M Lewandowska-Sabat
- Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences Oslo, Norway
| | - Ingrid Olsaker
- Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences Oslo, Norway
| | - Michael A Tranulis
- Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences Oslo, Norway
| | - Arild Espenes
- Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences Oslo, Norway
| | - Preben Boysen
- Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences Oslo, Norway
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10
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Seong YJ, Sung PS, Jang YS, Choi YJ, Park BC, Park SH, Park YW, Shin EC. Activation of human natural killer cells by the soluble form of cellular prion protein. Biochem Biophys Res Commun 2015; 464:512-8. [PMID: 26159919 DOI: 10.1016/j.bbrc.2015.06.172] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 06/30/2015] [Indexed: 01/19/2023]
Abstract
Cellular prion protein (PrP(C)) is widely expressed in various cell types, including cells of the immune system. However, the specific roles of PrP(C) in the immune system have not been clearly elucidated. In the present study, we investigated the effects of a soluble form of recombinant PrP(C) protein on human natural killer (NK) cells. Recombinant soluble PrP(C) protein was generated by fusion of human PrP(C) with the Fc portion of human IgG1 (PrP(C)-Fc). PrP(C)-Fc binds to the surface of human NK cells, particularly to CD56(dim) NK cells. PrP(C)-Fc induced the production of cytokines and chemokines and the degranulation of granzyme B from NK cells. In addition, PrP(C)-Fc facilitated the IL-15-induced proliferation of NK cells. PrP(C)-Fc induced phosphorylation of ERK-1/2 and JNK in NK cells, and inhibitors of the ERK or the JNK pathways abrogated PrP(C)-Fc-induced cytokine production in NK cells. In conclusion, the soluble form of recombinant PrP(C)-Fc protein activates human NK cells via the ERK and JNK signaling pathways.
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Affiliation(s)
- Yeon-Jae Seong
- Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, KAIST, Daejeon, Republic of Korea; Hafis Clinic, Seoul, Republic of Korea
| | - Pil Soo Sung
- Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, KAIST, Daejeon, Republic of Korea
| | - Young-Soon Jang
- Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, KAIST, Daejeon, Republic of Korea
| | - Young Joon Choi
- Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, KAIST, Daejeon, Republic of Korea
| | - Bum-Chan Park
- Aging Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Su-Hyung Park
- Laboratory of Translational Immunology and Vaccinology, Graduate School of Medical Science and Engineering, KAIST, Daejeon, Republic of Korea
| | - Young Woo Park
- Aging Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Eui-Cheol Shin
- Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, KAIST, Daejeon, Republic of Korea.
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11
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Onodera T, Sakudo A, Tsubone H, Itohara S. Review of studies that have used knockout mice to assess normal function of prion protein under immunological or pathophysiological stress. Microbiol Immunol 2015; 58:361-74. [PMID: 24866463 DOI: 10.1111/1348-0421.12162] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 05/22/2014] [Accepted: 05/26/2014] [Indexed: 12/29/2022]
Abstract
Deletion of cellular isoform of prion protein (PrP(C)) increases neuronal predisposition to damage by modulating apoptosis and the negative consequences of oxidative stress. In vivo studies have demonstrated that PrP(C)-deficient mice are more prone to seizure, depression, and induction of epilepsy and experience extensive cerebral damage following ischemic challenge or viral infection. In addition, adenovirus-mediated overexpression of PrP(C) reduces brain damage in rat models of cerebral ischemia. In experimental autoimmune encephalomyelitis, PrP(C)-deficient mice reportedly have a more aggressive disease onset and less clinical improvement during the chronic phase than wild-type mice mice. In mice given oral dextran sulfate, PrP(C) has a potential protective role against inflammatory bowel disease. PrP(C)-deficient mice demonstrate significantly greater increases in blood glucose concentrations after intraperitoneal injection of glucose than wild-type mice. Further in vivo challenges to PrP gene-deficient models and conditional knockout models with siRNA and in vivo administration of PrP-ligating agents may assist in refining knowledge of the lymphoid function of PrP(C) and predicting the effects of anti-PrP treatment on the immune system. Together, these findings indicate that PrP(C) may have multiple neuroprotective and anti-inflammatory roles, which explains why this protein is so widely expressed.
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Affiliation(s)
- Takashi Onodera
- Research Center for Food Safety, School of Agricultural and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-8657
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12
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Shott RH, Appanah C, Grenier C, Tremblay G, Roucou X, Schang LM. Development of kinomic analyses to identify dysregulated signaling pathways in cells expressing cytoplasmic PrP. Virol J 2014; 11:175. [PMID: 25280966 PMCID: PMC4283144 DOI: 10.1186/1743-422x-11-175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 09/26/2014] [Indexed: 12/20/2022] Open
Abstract
Background Dysregulated protein kinase signaling is involved in the pathogenesis of many chronic diseases. However, the dysregulated signaling pathways critical to prion pathogenesis remain incompletely characterized. Global analyses of signaling pathways may be useful to better characterize these pathways. We therefore set out to develop such global assays. To this end, we used as a model cytoplasmic mutants of the cellular prion protein (PrPC), which are toxic to N2a neuroblastoma cells. We tested the global assays for their sensitivity to detect changes in signaling pathways in cells expressing cytoplasmic PrP mutants. Methods We developed a targeted proteomics (kinomics) approach using multiplex Western blots to identify signaling pathways dysregulated in chronic neurological pathologies. We tested the approach for its potential ability to detect signaling changes in N2a cells expressing cytoplasmic PrP mutants. Results Multiplex Western blots were designed to quantitate the expression levels of 137 protein kinases in a single membrane and using only 1.2 mg of sample. The response of the blots was sensitive and linear to changes of 6% in protein levels. Hierarchical and functional clustering of the relative expression levels identified an mTOR signaling pathway as potentially dysregulated in N2a cells expressing cytoplasmic PrP. The mTOR signaling pathway regulates global protein synthesis, which is inhibited in cells expressing cytoplasmic PrP. The levels of proteins involved in the Akt1/p70S6K branch of mTOR signaling changed in synchrony with time of cytoplasmic PrP expression. Three kinases in this pathway, Akt, p70S6K, and eIF4B were in their inactive states, as evaluated by phosphorylation of their regulatory sites. Conclusion The results presented are consistent with the previously reported inhibition of Akt/p70S6K/eIF4B signaling as mediating pathogenesis of cytoplasmic PrP. We conclude that the kinomic analyses are sensitive and specific to detect signaling pathways dysregulated in a simple in vitro model of PrP pathogenesis. Electronic supplementary material The online version of this article (doi:10.1186/1743-422X-11-175) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | - Luis M Schang
- Department of Biochemistry and Centre for Prions and Protein Folding Diseases (CPPFD), University of Alberta, Edmonton, AB T6G 2E1, Canada.
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Jeon JW, Park BC, Jung JG, Jang YS, Shin EC, Park YW. The Soluble Form of the Cellular Prion Protein Enhances Phagocytic Activity and Cytokine Production by Human Monocytes Via Activation of ERK and NF-κB. Immune Netw 2013; 13:148-56. [PMID: 24009542 PMCID: PMC3759712 DOI: 10.4110/in.2013.13.4.148] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 07/19/2013] [Accepted: 07/22/2013] [Indexed: 02/01/2023] Open
Abstract
The PrP(C) is expressed in many types of immune cells including monocytes and macrophages, however, its function in immune regulation remains to be elucidated. In the present study, we examined a role for PrP(C) in regulation of monocyte function. Specifically, the effect of a soluble form of PrP(C) was studied in human monocytes. A recombinant fusion protein of soluble human PrP(C) fused with the Fc portion of human IgG1 (designated as soluble PrP(C)-Fc) bound to the cell surface of monocytes, induced differentiation to macrophage-like cells, and enhanced adherence and phagocytic activity. In addition, soluble PrP(C)-Fc stimulated monocytes to produce pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6. Both ERK and NF-κB signaling pathways were activated in soluble PrP(C)-treated monocytes, and inhibitors of either pathway abrogated monocyte adherence and cytokine production. Taken together, we conclude that soluble PrP(C)-Fc enhanced adherence, phagocytosis, and cytokine production of monocytes via activation of the ERK and NF-κB signaling pathways.
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Affiliation(s)
- Jae-Won Jeon
- Aging Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Korea
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14
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Williams SK, Fairless R, Weise J, Kalinke U, Schulz-Schaeffer W, Diem R. Neuroprotective effects of the cellular prion protein in autoimmune optic neuritis. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 178:2823-31. [PMID: 21641403 DOI: 10.1016/j.ajpath.2011.02.046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 02/15/2011] [Accepted: 02/23/2011] [Indexed: 10/18/2022]
Abstract
Although the pathologic role of the prion protein in transmissible spongiform encephalopathic diseases has been widely investigated, the physiologic role of the cellular prion protein (PrP(C)) is not known. Among the many functions attributed to PrP(C), there is increasing evidence that it is involved in cell survival and mediates neuroprotection. A potential role in the immune response has also been suggested. However, how these two functions interplay in autoimmune disease is unclear. To address this, autoimmune optic neuritis, a model of multiple sclerosis, was induced in C57Bl/6 mice, and up-regulation of PrP(C) was observed throughout the disease course. In addition, compared with wild-type mice, in PrP(C)-deficient mice and mice overexpressing PrP(C), histopathologic analysis demonstrated that optic neuritis was exacerbated, as indicated by axonal degeneration, inflammatory infiltration, and demyelination. However, significant neuroprotection of retinal ganglion cells, the axons of which form the optic nerve, was observed in mice that overexpressed PrP(C). Conversely, mice lacking PrP(C) demonstrated significantly more neurodegeneration. This suggests that PrP(C) may have a neuroprotective function independent of its role in regulating the immune response.
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Affiliation(s)
- Sarah K Williams
- Department of Neurology, University of the Saarland, Homburg/Saar, Germany.
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15
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Martin GR, Keenan CM, Sharkey KA, Jirik FR. Endogenous prion protein attenuates experimentally induced colitis. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:2290-301. [PMID: 21924230 DOI: 10.1016/j.ajpath.2011.07.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 07/07/2011] [Accepted: 07/13/2011] [Indexed: 02/07/2023]
Abstract
Although the cellular prion protein (PrP(C)) is expressed in the enteric nervous system and lamina propria, its function(s) in the gut is unknown. Because PrP(C) may exert a cytoprotective effect in response to various physiologic stressors, we hypothesized that PrP(C) expression levels might modulate the severity of experimental colitis. We evaluated the course of dextran sodium sulfate (DSS)-induced colitis in hemizygous Tga20 transgenic mice (approximately sevenfold overexpression of PrP(C)), Prnp(-/-) mice, and wild-type mice. On day 7, colon length, disease severity, and histologic activity indices were determined. Unlike DSS-treated wild-type and Prnp(-/-) animals, PrP(C) overexpressing mice were resistant to colitis induction, exhibited much milder histopathologic features, and did not exhibit weight loss or colonic shortening. In keeping with these results, pro-survival molecule expression and/or phosphorylation levels were elevated in DSS-treated Tga20 mice, whereas pro-inflammatory cytokine production and pSTAT3 levels were reduced. In contrast, DSS-treated Prnp(-/-) mice exhibited increased BAD protein expression and a cytokine expression profile predicted to favor inflammation and differentiation. PrP(C) expression from both the endogenous Prnp locus or the Tga20 transgene was increased in the colons of DSS-treated mice. Considered together, these findings demonstrate that PrP(C) has a previously unrecognized cytoprotective and/or anti-inflammatory function within the murine colon.
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Affiliation(s)
- Gary R Martin
- Department of Biochemistry and Molecular Biology and the McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, Alberta, Canada
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16
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Takakura I, Miyazawa K, Kanaya T, Itani W, Watanabe K, Ohwada S, Watanabe H, Hondo T, Rose MT, Mori T, Sakaguchi S, Nishida N, Katamine S, Yamaguchi T, Aso H. Orally administered prion protein is incorporated by m cells and spreads into lymphoid tissues with macrophages in prion protein knockout mice. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:1301-9. [PMID: 21763679 DOI: 10.1016/j.ajpath.2011.05.058] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 05/13/2011] [Accepted: 05/23/2011] [Indexed: 12/21/2022]
Abstract
Transmissible spongiform encephalopathies are fatal neurodegenerative diseases. Infection by the oral route is assumed to be important, although its pathogenesis is not understood. Using prion protein (PrP) knockout mice, we investigated the sequence of events during the invasion of orally administered PrPs through the intestinal mucosa and the spread into lymphoid tissues and the peripheral nervous system. Orally administered PrPs were incorporated by intestinal epitheliocytes in the follicle-associated epithelium and villi within 1 hour. PrP-positive cells accumulated in the subfollicle region of Peyer's patches a few hours thereafter. PrP-positive cells spread toward the mesenteric lymph nodes and spleen after the accumulation of PrPs in the Peyer's patches. The number of PrP molecules in the mesenteric lymph nodes and spleen peaked at 2 days and 6 days after inoculation, respectively. The epitheliocytes in the follicle-associated epithelium incorporating PrPs were annexin V-positive microfold cells and PrP-positive cells in Peyer's patches and spleen were CD11b-positive and CD14-positive macrophages. Additionally, PrP-positive cells in Peyer's patches and spleen were detected in the vicinity of peripheral nerve fibers in the early stages of infection. These results indicate that orally delivered PrPs were incorporated by microfold cells promptly after challenge and that macrophages might act as a transporter of incorporated PrPs from the Peyer's patches to other lymphoid tissues and the peripheral nervous system.
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Affiliation(s)
- Ikuro Takakura
- Cellular Biology Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
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The cellular prion protein in multiple sclerosis: A potential target for neurotherapeutics? Transl Neurosci 2011. [DOI: 10.2478/s13380-011-0042-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractMultiple sclerosis (MS) is a debilitating disease that affects millions. There is no known cure for the disease and neither is the cause of the disease known. Recent studies have indicated that it is a multi-factorial disease with several genes involved. Importantly, sunlight and vitamin D have been implicated in the progression of the disease. The pathogenesis of MS chiefly involves loss of oligodendrocytes, which in addition to being killed by inflammatory mediators in the CNS, also succumbs to loss of trophic support from astrocytes. Neurotrophins play an important role in myelination and the cellular prion protein (PrPC) is a key player in this process. Although the physiological roles of PrPC remain to be fully understood, increasing evidence suggests multiple roles for PrPC in regulation of cellular immunity and for its interaction with several neurotrophins that are necessary for homeostasis of the nervous system. This mini-review focuses on the findings establishing a crucial role for PrPC in the neuropathogenesis of MS, emphasizing its neuroprotective role. Since MS is a multi-factorial disease with unknown etiology and no cure, this review aims to highlight endogenous repair mechanisms mediated by PrPC that might contribute to functional recovery in MS patients.
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Didonna A, Legname G. Aberrant ERK 1/2 complex activation and localization in scrapie-infected GT1-1 cells. Mol Neurodegener 2010; 5:29. [PMID: 20696038 PMCID: PMC2928767 DOI: 10.1186/1750-1326-5-29] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Accepted: 08/09/2010] [Indexed: 11/15/2022] Open
Abstract
Background Fatal neurodegenerative disorders such as Creutzfeldt-Jakob and Gerstmann-Sträussler-Scheinker diseases in humans, scrapie and bovine spongiform encephalopathy in animals, are characterized by the accumulation in the brain of a pathological form of the prion protein (PrP) denominated PrPSc. The latter derives from the host cellular form, PrPC, through a process whereby portions of its α-helical and coil structures are refolded into β-sheet structures. Results In this work, the widely known in vitro model of prion replication, hypothalamic GT1-1 cell line, was used to investigate cellular and molecular responses to prion infection. The MAP kinase cascade was dissected to assess the phosphorylation levels of src, MEK 1/2 and ERK 1/2 signaling molecules, both before and after prion infection. Our findings suggest that prion replication leads to a hyper-activation of this pathway. Biochemical analysis was complemented with immunofluorescence studies to map the localization of the ERK complex within the different cellular compartments. We showed how the ERK complex relocates in the cytosol upon prion infection. We correlated these findings with an impairment of cell growth in prion-infected GT1-1 cells as probed by MTT assay. Furthermore, given the persistent urgency in finding compounds able to cure prion infected cells, we tested the effects on the ERK cascade of two molecules known to block prion replication in vitro, quinacrine and Fab D18. We were able to show that while these two compounds possess similar effects in curing prion infection, they affect the MAP kinase cascade differently. Conclusions Taken together, our results help shed light on the molecular events involved in neurodegeneration and neuronal loss in prion infection and replication. In particular, the combination of chronic activation and aberrant localization of the ERK complex may lead to a lack of essential neuroprotective and survival factors. Interestingly, these data seem to define some common traits with other neurodegenerative disorders such as, for example, Alzheimer's disease.
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Affiliation(s)
- Alessandro Didonna
- Laboratory of Prion Biology, Neurobiology Sector, Scuola Internazionale Superiore di Studi Avanzati (SISSA), via Bonomea 265, I-34136 Trieste, Italy.
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Toni M, Spisni E, Griffoni C, Santi S, Riccio M, Lenaz P, Tomasi V. Cellular prion protein and caveolin-1 interaction in a neuronal cell line precedes Fyn/Erk 1/2 signal transduction. J Biomed Biotechnol 2010; 2006:69469. [PMID: 17489019 PMCID: PMC1559926 DOI: 10.1155/jbb/2006/69469] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
It has been reported that cellular prion protein (PrPc) is enriched in caveolae or caveolae-like domains with caveolin-1 (Cav-1)
participating to signal transduction events by Fyn kinase recruitment. By using the Glutathione-S-transferase (GST)-fusion proteins
assay, we observed that PrPc strongly interacts in vitro with Cav-1. Thus, we ascertained the PrPc caveolar localization in a
hypothalamic neuronal cell line (GN11), by confocal microscopy analysis, flotation on density gradient, and coimmunoprecipitation
experiments. Following the anti-PrPc antibody-mediated stimulation of live GN11 cells, we observed that PrPc clustered on
plasma membrane domains rich in Cav-1 in which Fyn kinase converged to be activated. After these events, a signaling cascade
through p42/44 MAP kinase (Erk 1/2) was triggered, suggesting that following translocations from rafts to caveolae or caveolaelike
domains PrPc could interact with Cav-1 and induce signal transduction events.
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Affiliation(s)
- Mattia Toni
- Department of Experimental Biology, University of Bologna, Via Selmi 3, 40126 Bologna, Italy
| | - Enzo Spisni
- Department of Experimental Biology, University of Bologna, Via Selmi 3, 40126 Bologna, Italy
| | - Cristiana Griffoni
- Department of Experimental Biology, University of Bologna, Via Selmi 3, 40126 Bologna, Italy
| | - Spartaco Santi
- National Research Council, Institute of Cytomorphology, 40136 Bologna, Italy
| | - Massimo Riccio
- National Research Council, Institute of Cytomorphology, 40136 Bologna, Italy
| | - Patrizia Lenaz
- Department of Experimental Biology, University of Bologna, Via Selmi 3, 40126 Bologna, Italy
| | - Vittorio Tomasi
- Department of Experimental Biology, University of Bologna, Via Selmi 3, 40126 Bologna, Italy
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Hu W, Nessler S, Hemmer B, Eagar TN, Kane LP, Leliveld SR, Müller-Schiffmann A, Gocke AR, Lovett-Racke A, Ben LH, Hussain RZ, Breil A, Elliott JL, Puttaparthi K, Cravens PD, Singh MP, Petsch B, Stitz L, Racke MK, Korth C, Stüve O. Pharmacological prion protein silencing accelerates central nervous system autoimmune disease via T cell receptor signalling. ACTA ACUST UNITED AC 2010; 133:375-88. [PMID: 20145049 PMCID: PMC2822628 DOI: 10.1093/brain/awp298] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The primary biological function of the endogenous cellular prion protein has remained unclear. We investigated its biological function in the generation of cellular immune responses using cellular prion protein gene-specific small interfering ribonucleic acid in vivo and in vitro. Our results were confirmed by blocking cellular prion protein with monovalent antibodies and by using cellular prion protein-deficient and -transgenic mice. In vivo prion protein gene-small interfering ribonucleic acid treatment effects were of limited duration, restricted to secondary lymphoid organs and resulted in a 70% reduction of cellular prion protein expression in leukocytes. Disruption of cellular prion protein signalling augmented antigen-specific activation and proliferation, and enhanced T cell receptor signalling, resulting in zeta-chain-associated protein-70 phosphorylation and nuclear factor of activated T cells/activator protein 1 transcriptional activity. In vivo prion protein gene-small interfering ribonucleic acid treatment promoted T cell differentiation towards pro-inflammatory phenotypes and increased survival of antigen-specific T cells. Cellular prion protein silencing with small interfering ribonucleic acid also resulted in the worsening of actively induced and adoptively transferred experimental autoimmune encephalomyelitis. Finally, treatment of myelin basic protein1–11 T cell receptor transgenic mice with prion protein gene-small interfering ribonucleic acid resulted in spontaneous experimental autoimmune encephalomyelitis. Thus, central nervous system autoimmune disease was modulated at all stages of disease: the generation of the T cell effector response, the elicitation of T effector function and the perpetuation of cellular immune responses. Our findings indicate that cellular prion protein regulates T cell receptor-mediated T cell activation, differentiation and survival. Defects in autoimmunity are restricted to the immune system and not the central nervous system. Our data identify cellular prion protein as a regulator of cellular immunological homoeostasis and suggest cellular prion protein as a novel potential target for therapeutic immunomodulation.
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Affiliation(s)
- Wei Hu
- Department of Neurology, University of Texas Southwestern Medical Center at Dallas, TX, USA
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21
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Ermonval M, Baudry A, Baychelier F, Pradines E, Pietri M, Oda K, Schneider B, Mouillet-Richard S, Launay JM, Kellermann O. The cellular prion protein interacts with the tissue non-specific alkaline phosphatase in membrane microdomains of bioaminergic neuronal cells. PLoS One 2009; 4:e6497. [PMID: 19652718 PMCID: PMC2715859 DOI: 10.1371/journal.pone.0006497] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Accepted: 06/26/2009] [Indexed: 11/29/2022] Open
Abstract
Background The cellular prion protein, PrPC, is GPI anchored and abundant in lipid rafts. The absolute requirement of PrPC in neurodegeneration associated to prion diseases is well established. However, the function of this ubiquitous protein is still puzzling. Our previous work using the 1C11 neuronal model, provided evidence that PrPC acts as a cell surface receptor. Besides a ubiquitous signaling function of PrPC, we have described a neuronal specificity pointing to a role of PrPC in neuronal homeostasis. 1C11 cells, upon appropriate induction, engage into neuronal differentiation programs, giving rise either to serotonergic (1C115-HT) or noradrenergic (1C11NE) derivatives. Methodology/Principal Findings The neuronal specificity of PrPC signaling prompted us to search for PrPC partners in 1C11-derived bioaminergic neuronal cells. We show here by immunoprecipitation an association of PrPC with an 80 kDa protein identified by mass spectrometry as the tissue non-specific alkaline phosphatase (TNAP). This interaction occurs in lipid rafts and is restricted to 1C11-derived neuronal progenies. Our data indicate that TNAP is implemented during the differentiation programs of 1C115-HT and 1C11NE cells and is active at their cell surface. Noteworthy, TNAP may contribute to the regulation of serotonin or catecholamine synthesis in 1C115-HT and 1C11NE bioaminergic cells by controlling pyridoxal phosphate levels. Finally, TNAP activity is shown to modulate the phosphorylation status of laminin and thereby its interaction with PrP. Conclusion/Significance The identification of a novel PrPC partner in lipid rafts of neuronal cells favors the idea of a role of PrP in multiple functions. Because PrPC and laminin functionally interact to support neuronal differentiation and memory consolidation, our findings introduce TNAP as a functional protagonist in the PrPC-laminin interplay. The partnership between TNAP and PrPC in neuronal cells may provide new clues as to the neurospecificity of PrPC function.
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Affiliation(s)
- Myriam Ermonval
- Différenciation cellulaire et Prions, Institut Pasteur, Département de Biologie Cellulaire et Infection, Paris, France
- CNRS FRE 2937, Villejuif, France
- * E-mail: (ME); (OK)
| | - Anne Baudry
- Différenciation cellulaire et Prions, Institut Pasteur, Département de Biologie Cellulaire et Infection, Paris, France
- CNRS FRE 2937, Villejuif, France
| | | | - Elodie Pradines
- Différenciation cellulaire et Prions, Institut Pasteur, Département de Biologie Cellulaire et Infection, Paris, France
- CNRS FRE 2937, Villejuif, France
| | - Mathéa Pietri
- Différenciation cellulaire et Prions, Institut Pasteur, Département de Biologie Cellulaire et Infection, Paris, France
- CNRS FRE 2937, Villejuif, France
| | - Kimimitsu Oda
- Division of Oral Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Niigata City, Japan
| | - Benoît Schneider
- Différenciation cellulaire et Prions, Institut Pasteur, Département de Biologie Cellulaire et Infection, Paris, France
- CNRS FRE 2937, Villejuif, France
| | - Sophie Mouillet-Richard
- Différenciation cellulaire et Prions, Institut Pasteur, Département de Biologie Cellulaire et Infection, Paris, France
- CNRS FRE 2937, Villejuif, France
| | - Jean-Marie Launay
- AP-HP Service de Biochimie, U942 INSERM Hôpital Lariboisière, Paris, France
- Pharma Research Department, F. Hoffmann-La-Roche, Basel, Switzerland
| | - Odile Kellermann
- Différenciation cellulaire et Prions, Institut Pasteur, Département de Biologie Cellulaire et Infection, Paris, France
- CNRS FRE 2937, Villejuif, France
- * E-mail: (ME); (OK)
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Kuczius T, Karch H, Groschup MH. Differential solubility of prions is associated in manifold phenotypes. Mol Cell Neurosci 2009; 42:226-33. [PMID: 19607920 DOI: 10.1016/j.mcn.2009.07.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2009] [Revised: 06/12/2009] [Accepted: 07/02/2009] [Indexed: 12/12/2022] Open
Abstract
The main feature of prion diseases is the accumulation of infectious proteins (PrP(Sc)). Since PrP(Sc) results from conversion of cellular prion proteins (PrP(C)), differential expressed PrP(C) types may play an important role in the formation and conversion efficiency to specific PrP(Sc) forms. However, little is known about the PrP(C) expression, regulation and differentiation. Here, we demonstrate a new type of differentiation of overlapping PrP(C) isoforms in brain homogenates using differential SDS solubility. Low and highly soluble PrP(C) were detected along with various types of protein which are present in the brain of non-infected humans, sheep and cattle. Our findings provide evidence for the existence of several overlapping PrP(C) proteins exhibiting distinct glycotypes. The selection of defined PrP(C) types offers new possibilities for identifying highly efficient converting proteins and provides the potential for disease control.
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Affiliation(s)
- Thorsten Kuczius
- Institute for Hygiene, Westfälische Wilhelms-University Münster and University Hospital Münster, Robert Koch-Strasse 41, 48149 Münster, Germany.
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23
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Pantera B, Bini C, Cirri P, Paoli P, Camici G, Manao G, Caselli A. PrPc activation induces neurite outgrowth and differentiation in PC12 cells: role for caveolin-1 in the signal transduction pathway. J Neurochem 2009; 110:194-207. [PMID: 19457127 DOI: 10.1111/j.1471-4159.2009.06123.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Cellular prion protein (PrP(c)) is a ubiquitous glycoprotein, whose physiological role is poorly characterized. It has been suggested that PrP(c) participates in neuritogenesis, neuroprotection, copper metabolism, and signal transduction. In this study we detailed the intracellular events induced by PrP(c) antibody-mediated cross-linking in PC12 cells. We found a Fyn-dependent activation of the Ras-Raf pathway, which leads to a rapid and transient phosphorylation of extracellular regulated kinases. In addition, this activation cascade relies on the engagement of integrins, and involves focal adhesion kinase activation. We demonstrated the tyrosine phosphorylation of caveolin-1 as a consequence of PrP(c) stimulation, and showed that phosphocaveolin-1 scaffolds and coordinates protein complexes involved in PrP(c)-dependent signaling. Moreover, we found that caveolin-1 phosphorylation, is a mechanism for recruiting the C-terminal Src kinase and inactivating Fyn, so as to terminate cell signaling. Furthermore our data support a significant role for PrP(c) as a response mediator in neuritogenesis and cell differentiation.
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Affiliation(s)
- Barbara Pantera
- Dipartimento di Scienze Biochimiche, Università degli Studi di Firenze, Italy
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24
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Zhou H, Zhou X, Kouadir M, Zhang Z, Yin X, Yang L, Zhao D. Induction of macrophage migration by neurotoxic prion protein fragment. J Neurosci Methods 2009; 181:1-5. [PMID: 19447501 DOI: 10.1016/j.jneumeth.2009.04.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Revised: 04/02/2009] [Accepted: 04/03/2009] [Indexed: 01/07/2023]
Abstract
Prion diseases are characterized by accumulation of protease resistant isoforms of prion protein (PrP), and infiltration and activation of mononuclear phagocytes at the brain lesions. Interactions between prion proteins and immune cells during disease progression are still not very well understood. In the present study, multiwell chamber chemotaxis assay was carried out to assess the migratory response of macrophage cell line Ana-1 to a synthetic peptide homologous to residues 106-126 of the human prion protein. Specific protein kinase inhibitors were used to elucidate the signaling events underlying PrP106-126-induced macrophages migration, and a comparison with the signaling pattern of macrophage migration induced by substance P (SP) and N-formyl-methionyl-leucyl-phenylalanine (fMLP), respectively, was carried out. The results showed that PrP106-126 had a potent chemotactic effect on murine macrophage cell line Ana-1; that multiple signaling pathways might be involved in the PrP106-126-induced macrophage migrations; and that PrP106-126-induced chemotactic activity was similar to that induced by SP. These findings provide new insights into the mechanisms underlying the interaction between PrP and macrophages.
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Affiliation(s)
- Haiyun Zhou
- National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, People's Republic of China
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Malaisé M, Schätzl HM, Bürkle A. The octarepeat region of prion protein, but not the TM1 domain, is important for the antioxidant effect of prion protein. Free Radic Biol Med 2008; 45:1622-30. [PMID: 18824094 DOI: 10.1016/j.freeradbiomed.2008.08.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 07/23/2008] [Accepted: 08/20/2008] [Indexed: 01/06/2023]
Abstract
The cellular prion protein (PrP(c)) plays a crucial role in the pathogenesis of prion diseases, but its physiological function is far from understood. Several candidate functions have been proposed including binding and internalization of metal ions, a superoxide dismutase-like activity, regulation of cellular antioxidant activities, and signal transduction. The transmembrane (TM1) region of PrP(c) (residues 110-135) is particularly interesting because of its very high evolutionary conservation. We investigated a possible role of TM1 in the antioxidant defense, by assessing the impact of overexpressing wt-PrP or deletion mutants in N(2)A mouse neuroblastoma cells on intracellular reactive oxygen species (ROS) levels. Under conditions of oxidative stress, intracellular ROS levels were significantly lowered in cells overexpressing either wild-type PrP(c) (wt-PrP) or a deletion mutant affecting TM1 (Delta8TM1-PrP), but, as expected, not in cultures overexpressing a deletion mutant lacking the octapeptide region (Deltaocta-PrP). Overexpression of wt-PrP, Delta8TM1-PrP, or Deltaocta-PrP did not affect basal ROS levels. Interestingly, the mitochondrial membrane potential was significantly lowered in Deltaocta-PrP-transfected cultures in the absence of oxidative stress. We conclude that the protective effect of PrP(c) against oxidative stress involves the octarepeat region but not the TM1 domain nor the high-affinity copper binding site described for human residues His96/His111.
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Affiliation(s)
- Muriel Malaisé
- Molecular Toxicology Group, Department of Biology, University of Konstanz, Konstanz, Germany
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Ermonval M, Petit D, Le Duc A, Kellermann O, Gallet PF. Glycosylation-related genes are variably expressed depending on the differentiation state of a bioaminergic neuronal cell line: implication for the cellular prion protein. Glycoconj J 2008; 26:477-93. [PMID: 18937066 DOI: 10.1007/s10719-008-9198-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Revised: 09/17/2008] [Accepted: 10/01/2008] [Indexed: 12/26/2022]
Abstract
A striking feature of the cellular prion protein (PrP(C)) is the heterogeneity of its glycoforms, whose contribution to PrP(C) function has yet to be defined. Using the 1C11 neuronal bioaminergic differentiation model and a glycomics approach, we show here a correlation between differential PrP(C) N-glycosylations in 1C11(5-HT) serotonergic and 1C11(NE) noradrenergic cells compared to their 1C11 precursor cells and a variation of the glycogenome expression status in these cells. In particular, expression of genes involved in N-glycan synthesis or in the modeling of chondroitin and heparan sulfate proteoglycans appeared to be modulated. Our results highlight that, the expression of glycosylation-related genes is regulated during bioaminergic neuronal differentiation, consistent with a participation of glycoconjugates in neuronal development and plasticity. A neuronal regulation of glycosylation processes may have direct implications on some neurospecific functions of PrP(C) and may participate in specific brain targeting of prion strains.
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Affiliation(s)
- Myriam Ermonval
- Différenciation Cellulaire et Prions, Département de Biologie Cellulaire et Infections, Institut Pasteur, 75015, Paris, France.
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Schmalzbauer R, Eigenbrod S, Winoto-Morbach S, Xiang W, Schtze S, Bertsch U, Kretzschmar HA. Evidence for an association of prion protein and sphingolipid-mediated signaling. J Neurochem 2008; 106:1459-70. [DOI: 10.1111/j.1471-4159.2008.05498.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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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.
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Affiliation(s)
- Rafael Linden
- Instituto de Biofísica da Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
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29
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Hu W, Kieseier B, Frohman E, Eagar TN, Rosenberg RN, Hartung HP, Stüve O. Prion proteins: Physiological functions and role in neurological disorders. J Neurol Sci 2008; 264:1-8. [PMID: 17707411 DOI: 10.1016/j.jns.2007.06.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2007] [Revised: 05/01/2007] [Accepted: 06/08/2007] [Indexed: 02/01/2023]
Abstract
Stanley Prusiner was the first to promote the concept of misfolded proteins as a cause for neurological disease. It has since been shown by him and other investigators that the scrapie isoform of prion protein (PrP(Sc)) functions as an infectious agent in numerous human and non-human disorders of the central nervous system (CNS). Interestingly, other organ systems appear to be less affected, and do not appear to lead to major co-morbidities. The physiological function of the endogenous cellular form of the prion protein (PrP(C)) is much less clear. It is intriguing that PrP(c) is expressed on most tissues in mammals, suggesting not only biological functions outside the CNS, but also a role other than the propagation of its misfolded isotype. In this review, we summarize accumulating in vitro and in vivo evidence regarding the physiological functions of PrP(C) in the nervous system, as well as in lymphoid organs.
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Affiliation(s)
- Wei Hu
- Department of Neurology, University of Texas Southwestern Medical Center at Dallas, TX 75390-9036, United States
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30
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Gilch S, Schmitz F, Aguib Y, Kehler C, Bülow S, Bauer S, Kremmer E, Schätzl HM. CpG and LPS can interfere negatively with prion clearance in macrophage and microglial cells. FEBS J 2007; 274:5834-44. [PMID: 17944938 DOI: 10.1111/j.1742-4658.2007.06105.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Cells of the innate immune system play important roles in the progression of prion disease after peripheral infection. It has been found in vivo and in vitro that the expression of the cellular prion protein (PrP(c)) is up-regulated on stimulation of immune cells, also indicating the functional importance of PrP(c) in the immune system. The aim of our study was to investigate the impact of cytosine-phosphate-guanosine- and lipopolysaccharide-induced PrP(c) up-regulation on the uptake and processing of the pathological prion protein (PrP(Sc)) in phagocytic innate immune cells. For this purpose, we challenged the macrophage cell line J774, the microglial cell line BV-2 and primary bone marrow-derived macrophages in a resting or stimulated state with various prion strains, and monitored the uptake and clearance of PrP(Sc). Interestingly, stimulation led either to a transient increase in the level of PrP(Sc) relative to unstimulated cells or to a decelerated degradation of PrP(Sc). These features were dependent on cell type and prion strain. Our data indicate that the stimulation of innate immune cells may be able to support transient prion propagation, possibly explained by an increased PrP(c) cell surface expression in stimulated cells. We suggest that stimulation of innate immune cells can lead to an imbalance between the propagation and degradation of PrP(Sc).
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Affiliation(s)
- Sabine Gilch
- Institute of Virology, Prion Research Group, Technical University of Munich, Germany
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Sakudo A, Onodera T, Ikuta K. Prion protein gene-deficient cell lines: powerful tools for prion biology. Microbiol Immunol 2007; 51:1-13. [PMID: 17237594 DOI: 10.1111/j.1348-0421.2007.tb03877.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Prion diseases are zoonotic infectious diseases commonly transmissible among animals via prion infections with an accompanying deficiency of cellular prion protein (PrP(C)) and accumulation of an abnormal isoform of prion protein (PrP(Sc)), which are observed in neurons in the event of injury and disease. To understand the role of PrP(C) in the neuron in health and diseases, we have established an immortalized neuronal cell line HpL3-4 from primary hippocampal cells of prion protein (PrP) gene-deficient mice by using a retroviral vector encoding Simian Virus 40 Large T antigen (SV40 LTag). The HpL3-4 cells exhibit cell-type-specific proteins for the neuronal precursor lineage. Recently, this group and other groups have established PrP-deficient cell lines from many kinds of cell types including glia, fibroblasts and neuronal cells, which will have a broad range of applications in prion biology. In this review, we focus on recently obtained information about PrP functions and possible studies on prion infections using the PrPdeficient cell lines.
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Affiliation(s)
- Akikazu Sakudo
- Department of Virology, Research Institute for Microbial Diseases, Osaka University, Japan.
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Abstract
The biological role of the scrapie isoform of prion protein (PrP(Sc)) as an infectious agent in numerous human and non-human disorders of the central nervous system is well established. In contrast, and despite decades of intensive research, the physiological function of the endogenous cellular form of the prion protein (PrP(C)) remains elusive. In mammals, the ubiquitous expression of PrP(C) suggests biological functions other than its pathological role in propagating the accumulation of its misfolded isotype. Other functions that have been attributed to PrP(C) include signal transduction, synaptic transmission and protection against cell death through the apoptotic pathway. More recently, immunoregulatory properties of PrP(C) have been reported. We review accumulating in vitro and in vivo evidence regarding physiological functions of PrP(C).
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Affiliation(s)
- W Hu
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Dallas, TX 75390-9036, USA
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Lee KJ, Panzera A, Rogawski D, Greene LE, Eisenberg E. Cellular prion protein (PrPC) protects neuronal cells from the effect of huntingtin aggregation. J Cell Sci 2007; 120:2663-71. [PMID: 17635996 DOI: 10.1242/jcs.004598] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The effect of normal cellular prion protein (PrP(C)) on abnormal protein aggregation was examined by transfecting huntingtin fragments (Htt) into SN56 neuronal-derived cells depleted of PrP(C) by RNA interference. PrP(C) depletion caused an increase in both the number of cells containing granules and the number of apoptotic cells. Consistent with the increase in Htt aggregation, PrP(C) depletion caused an decrease in proteasome activity and a decrease in the activities of cellular defense enzymes compared with control cells whereas reactive oxygen species (ROS) increased more than threefold. Therefore, PrP(C) may protect against Htt toxicity in neuronal cells by increasing cellular defense proteins, decreasing ROS and increasing proteasome activity thereby increasing Htt degradation. Depletion of endogenous PrP(C) in non-neuronal Caco-2 and HT-29 cells did not affect ROS levels or proteasome activity suggesting that only in neuronal cells does PrP(C) confer protection against Htt toxicity. The protective effect of PrP(C) was further evident in that overexpression of mouse PrP(C) in SN56 cells transfected with Htt caused a decrease in both the number of cells with Htt granules and the number of apoptotic cells, whereas there was no effect of PrP(C) expression in non-neuronal NIH3T3 or CHO cells. Finally, in chronically scrapie (PrP(Sc))-infected cells, ROS increased more than twofold while proteasome activity was decreased compared to control cells. Although this could be a direct effect of PrP(Sc), it is also possible that, since PrP(C) specifically prevents pathological protein aggregation in neuronal cells, partial loss of PrP(C) itself increases PrP(Sc) aggregation.
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Affiliation(s)
- Kyung-Jin Lee
- Laboratory of Cell Biology, NHBLI, NIH, Bethesda, MD 20892-0301, USA
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Liang J, Pan Y, Zhang D, Guo C, Shi Y, Wang J, Chen Y, Wang X, Liu J, Guo X, Chen Z, Qiao T, Fan D. Cellular prion protein promotes proliferation and G1/S transition of human gastric cancer cells SGC7901 and AGS. FASEB J 2007; 21:2247-56. [PMID: 17409275 DOI: 10.1096/fj.06-7799com] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The function of cellular prion protein (PrP(C)), the essential protein for the pathogenesis and transmission of prion diseases, is still largely unknown. The putative roles of PrP(C) are thought to be related to cell signaling, survival, and differentiation. In a previous study, we showed that PrP(C) was overexpressed in gastric cancer tissues. In the present report, we show that ectopic expression of PrP(C) could promote tumorigenesis, proliferation, and G1/S transition in gastric cancer cells. Furthermore, CyclinD1, a protein related to cell cycle, was shown to be significantly up-regulated by PrP(C) at both mRNA and protein levels. PI3K/Akt pathway mediated above PrP(C) signal since PrP(C) increased the expression of phosphorylated Akt, and the specific inhibitor of Akt, LY294002, could markedly suppress growth of SGC7901 and transactivation of CyclinD1 induced by PrP(C). Octapeptide repeat region played a vital role in this function, as deletion of this region abolished or reduced these effects. Collectively, this study demonstrates that overexpression of PrP(C) might promote the tumorigenesis and proliferation of gastric cancer cells at least partially through activation of PI3K/Akt pathway and subsequent transcriptional activation of CyclinD1 to regulate the G1/S phase transition, in which octapeptide repeat region might be an indispensable region.
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MESH Headings
- Animals
- Cell Division/drug effects
- Cell Line, Tumor
- Cell Transformation, Neoplastic/genetics
- Chromones/pharmacology
- Cyclin D
- Cyclins/biosynthesis
- Cyclins/genetics
- Cyclins/physiology
- G1 Phase
- Gene Expression Regulation, Neoplastic/drug effects
- Humans
- Mice
- Mice, Inbred BALB C
- Mice, Nude
- Morpholines/pharmacology
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Neoplasm Proteins/physiology
- Neoplasm Transplantation
- Phosphatidylinositol 3-Kinases/physiology
- PrPC Proteins/chemistry
- PrPC Proteins/genetics
- PrPC Proteins/physiology
- Proto-Oncogene Proteins c-akt/antagonists & inhibitors
- Proto-Oncogene Proteins c-akt/physiology
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- RNA, Neoplasm/biosynthesis
- RNA, Neoplasm/genetics
- Recombinant Fusion Proteins/physiology
- Repetitive Sequences, Amino Acid
- S Phase
- Sequence Deletion
- Signal Transduction/genetics
- Signal Transduction/physiology
- Stomach Neoplasms/genetics
- Stomach Neoplasms/pathology
- Transcriptional Activation/drug effects
- Transfection
- Tumor Stem Cell Assay
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Affiliation(s)
- Jie Liang
- State Key Laboratory of Cancer Biology, Xijing Hospital, Fourth Military Medical University, 15 West Chang-Le Rd., Xi'an, Shaanxi Province, China
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Mouillet-Richard S, Schneider B, Pradines E, Pietri M, Ermonval M, Grassi J, Richards JG, Mutel V, Launay JM, Kellermann O. Cellular Prion Protein Signaling in Serotonergic Neuronal Cells. Ann N Y Acad Sci 2007; 1096:106-19. [PMID: 17405922 DOI: 10.1196/annals.1397.076] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The cellular prion protein PrP(C) is the normal counterpart of the scrapie prion protein PrP(Sc), the main component of the infectious agent of transmissible spongiform encephalopathies (TSEs). It is a ubiquitous cell-surface glycoprotein, abundantly expressed in neurons, which constitute the targets of TSE pathogenesis. Taking advantage of the 1C11 neuroectodermal cell line, endowed with the capacity to convert into 1C11(5-HT) serotonergic or 1C11(NE) noradrenergic neuronal cells, allowed us to ascribe a signaling function to PrP(C). Antibody-mediated ligation of PrP(C) recruits transduction pathways, which involve nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-dependent reactive oxygen species production and target the extracellular-regulated kinases ERK1/2. In fully differentiated cells only, these effectors are under the control of a PrP(C)-caveolin-Fyn platform, located on neuritic extensions. In addition to its proper signaling activity, PrP(C) modulates the agonist-induced response of the three serotonergic G protein-coupled receptors present on the 1C11(5-HT) differentiated cells. The impact of PrP(C) ligation on the receptor couplings depends on the receptor subtype and the pathway considered. The implementation of the PrP(C)-caveolin complex again is mandatory for PrP(C) to exert its action on 5-HT receptor signaling. Our current data argue that PrP(C) interferes with the intensities and/or dynamics of G protein activation by agonist-bound 5-HT receptors. By mobilizing transduction cascades controlling the cellular redox state and the ERK1/2 kinases and by altering 5-HT receptor-mediated intracellular response, PrP(C) takes part in the homeostasis of serotonergic neuronal cells. These findings may have implications for future research aiming at understanding the fate of serotonergic neurons in prion diseases.
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Affiliation(s)
- Sophie Mouillet-Richard
- Différenciation cellulaire et prions, CNRS FRE 2937 7, rue Guy Moquet 94801 Villejuif, France.
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36
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Abstract
Prion protein (PrP) plays a key role in the pathogenesis of prion diseases. However, the normal function of the protein remains unclear. The cellular isoform (PrP(C)) is expressed widely in the immune system, in haematopoietic stem cells and mature lymphoid and myeloid compartments in addition to cells of the central nervous system. It is up-regulated in T cell activation and may be expressed at higher levels by specialized classes of lymphocyte. Furthermore, antibody cross-linking of surface PrP modulates T cell activation and leads to rearrangements of lipid raft constituents and increased phosphorylation of signalling proteins. These findings appear to indicate an important but, as yet, ill-defined role in T cell function. Although PrP(-/-) mice have been reported to have only minor alterations in immune function, recent work has suggested that PrP is required for self-renewal of haematopoietic stem cells. Here, we consider the evidence for a distinctive role for PrP(C) in the immune system and what the effects of anti-prion therapeutics may be on immune function.
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Affiliation(s)
- J D Isaacs
- Human Disease Immunogenetics Group, Department of Infectious Diseases and Immunity, Imperial College London, Hammersmith Hospital, London, UK
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37
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Coitinho AS, Freitas ARO, Lopes MH, Hajj GNM, Roesler R, Walz R, Rossato JI, Cammarota M, Izquierdo I, Martins VR, Brentani RR. The interaction between prion protein and laminin modulates memory consolidation. Eur J Neurosci 2006; 24:3255-64. [PMID: 17156386 DOI: 10.1111/j.1460-9568.2006.05156.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Cellular prion protein (PrPc) has a pivotal role in prion diseases. PrPc is a specific receptor for laminin (LN) gamma1 peptide and several lines of evidence indicate that it is also involved in neural plasticity. Here we investigated whether the interaction between PrPc and LN plays a role in rat memory formation. We found that post-training intrahippocampal infusion of PrPc-derived peptides that contain the LN binding site (PrPc163-182 and PrPc173-192) or of anti-PrPc or anti-LN antibodies that inhibit PrPc-LN interaction impaired inhibitory avoidance memory retention. The amnesic effect of anti-PrPc antibodies and PrPc173-192 peptide was reversed by co-infusion of a LN gamma1 chain-derived peptide containing the PrPc-binding site, suggesting that PrPc-LN interaction is indeed crucial for memory consolidation. In addition, PrPc173-192 peptide and anti-PrPc or anti-LN antibodies also inhibited the activation of hippocampal cAMP-dependent protein kinase A (PKA) and extracellular regulated kinase (ERK1/2), two kinases that mediate the up-regulation of signaling pathways needed for consolidation of inhibitory avoidance memory. Our findings show that, through its interaction with LN, hippocampal PrPc plays a critical role in memory processing and suggest that this role is mediated by activation of both PKA and ERK1/2 signaling pathways.
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Affiliation(s)
- Adriana S Coitinho
- Centro Universitário Feevale, Instituto de Ciências da Saúde, RS 239, 2755, 93352-000, Novo Hamburgo, RS, and Centro de Cirurgia de Epilepsia do Estado de Santa Catarina, Hospital Governador Celso Ramos, SC, Brazil
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Adle-Biassette H, Verney C, Peoc'h K, Dauge MC, Razavi F, Choudat L, Gressens P, Budka H, Henin D. Immunohistochemical expression of prion protein (PrPC) in the human forebrain during development. J Neuropathol Exp Neurol 2006; 65:698-706. [PMID: 16825956 DOI: 10.1097/01.jnen.0000228137.10531.72] [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: 02/03/2023] Open
Abstract
The cellular prion protein (PrPC) is a ubiquitous protein whose expression in the adult brain occurs mainly in synapses. We used monoclonal antibodies to study fetal and perinatal PrPC expression in the human forebrain. Double immunofluorescence and confocal microscopy with GFAP, Iba1, MAP2, doublecortin, synaptophysin, and GAP-43 were used to localize PrPC. PrPC immunoreactivity was observed in axonal tracts and fascicles from the 11th week to the end of gestation. Synapses expressed PrPC at increasing levels throughout synaptogenesis. At midgestation, a few PrPC-labeled neurons were detected in the cortical anlage and numerous ameboid and intermediate microglial cells were PrPC-positive. In contrast, at the end of gestation, microglial PrPC expression decreased to almost nothing, whereas neuronal PrPC expression increased, most notably in ischemic areas. In adults, PrPC immunoreactivity was restricted to the synaptic neuropil of the gray matter. At all ages, choroid plexus, ependymal, and endothelial cells were labeled, whereas astrocytes were only occasionally immunoreactive. In conclusion, the early expression of PrPC in the axonal field may suggest a specific role for this molecule in axonal growth during development. Moreover, PrPC may play a role in early microglial cell development.
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Affiliation(s)
- Homa Adle-Biassette
- AP HP, Hôpital Bichat-Claude Bernard, Service d'Anatomie Pathologie, Université Paris 7, Faculté de Médecine Denis Diderot, Paris, France.
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39
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Fuhrmann M, Bittner T, Mitteregger G, Haider N, Moosmang S, Kretzschmar H, Herms J. Loss of the cellular prion protein affects the Ca2+ homeostasis in hippocampal CA1 neurons. J Neurochem 2006; 98:1876-85. [PMID: 16945105 DOI: 10.1111/j.1471-4159.2006.04011.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Previous neurophysiological studies on prion protein deficient (Prnp(-/-)) mice have revealed a significant reduction of slow afterhyperpolarization currents (sI(AHP)) in hippocampal CA1 pyramidal cells. Here we aim to determine whether loss of PrP(C.) directly affects the potassium channels underlying sI(AHP) or if sI(AHP) is indirectly disturbed by altered intracellular Ca(2+) fluxes. Patch-clamp measurements and confocal Ca(2+) imaging in acute hippocampal slice preparations of Prnp(-/-) mice compared to littermate control mice revealed a reduced Ca(2+) rise in CA1 neurons lacking PrP(C) following a depolarization protocol known to induce sI(AHP). Moreover, we observed a reduced Ca(2+) influx via l-type voltage gated calcium channels (VGCCs). No differences were observed in the protein expression of the pore forming alpha1 subunit of VGCCs Prnp(-/-) mice. Surprisingly, the beta2 subunit, critically involved in the transport of the alpha1 subunit to the plasma membrane, was found to be up-regulated in knock out hippocampal tissue. On mRNA level however, no differences could be detected for the alpha1C, D and beta2-4 subunits. In conclusion our data support the notion that lack of PrP(C.) does not directly affect the potassium channels underlying sI(AHP), but modulates these channels due to its effect on the intracellular free Ca(2+) concentration via a reduced Ca(2+) influx through l-type VGCCs.
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Affiliation(s)
- Martin Fuhrmann
- Center of Neuropathology and Prion Research, Ludwig Maximilians University, 81377 Munich, Germany
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