1
|
Marques CMS, Pedron T, Batista BL, Cerchiaro G. Cellular prion protein activates Caspase 3 for apoptotic defense mechanism in astrocytes. Mol Cell Biochem 2021; 476:2149-2158. [PMID: 33547547 DOI: 10.1007/s11010-021-04078-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 01/25/2021] [Indexed: 12/31/2022]
Abstract
The cellular prion protein (PrPC) is anchored in the plasma membrane of cells, and it is highly present in cells of brain tissue, exerting numerous cellular and cognitive functions. The present study proves the importance of PrPC in the cellular defense mechanism and metal homeostasis in astrocytes cells. Through experimental studies using cell lines of immortalized mice astrocytes (wild type and knockout for PrPC), we showed that PrPc is involved in the apoptosis cell death process by the activation of Caspase 3, downregulation of p53, and cell cycle maintenance. Metal homeostasis was determined by inductively coupled plasma mass spectrometry technique, indicating the crucial role of PrPC to lower intracellular calcium. The lowered calcium concentration and the Caspase 3 downregulation in the PrPC-null astrocytes resulted in a faster growth rate in cells, comparing with PrPC wild-type one. The presence of PrPC shows to be essential to cell death and healthy growth. In conclusion, our results show for the first time that astrocyte knockout cells for the cellular prion protein could modulate apoptosis-dependent cell death pathways.
Collapse
Affiliation(s)
- Caroline M S Marques
- Center for Natural Sciences and Humanities, Federal University of ABC (UFABC), Avenida dos Estados, 5001, Bl.B, Santo André, SP, 09210-580, Brazil
| | - Tatiana Pedron
- Center for Natural Sciences and Humanities, Federal University of ABC (UFABC), Avenida dos Estados, 5001, Bl.B, Santo André, SP, 09210-580, Brazil
| | - Bruno L Batista
- Center for Natural Sciences and Humanities, Federal University of ABC (UFABC), Avenida dos Estados, 5001, Bl.B, Santo André, SP, 09210-580, Brazil
| | - Giselle Cerchiaro
- Center for Natural Sciences and Humanities, Federal University of ABC (UFABC), Avenida dos Estados, 5001, Bl.B, Santo André, SP, 09210-580, Brazil.
| |
Collapse
|
2
|
The Prion Protein Regulates Synaptic Transmission by Controlling the Expression of Proteins Key to Synaptic Vesicle Recycling and Exocytosis. Mol Neurobiol 2018; 56:3420-3436. [PMID: 30128651 DOI: 10.1007/s12035-018-1293-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 08/01/2018] [Indexed: 12/16/2022]
Abstract
The cellular prion protein (PrPC), whose misfolded conformers are implicated in prion diseases, localizes to both the presynaptic membrane and postsynaptic density. To explore possible molecular contributions of PrPC to synaptic transmission, we utilized a mass spectrometry approach to quantify the release of glutamate from primary cerebellar granule neurons (CGN) expressing, or deprived of (PrP-KO), PrPC, following a depolarizing stimulus. Under the same conditions, we also tracked recycling of synaptic vesicles (SVs) in the two neuronal populations. We found that in PrP-KO CGN these processes decreased by 40 and 60%, respectively, compared to PrPC-expressing neurons. Unbiased quantitative mass spectrometry was then employed to compare the whole proteome of CGN with the two PrP genotypes. This approach allowed us to assess that, relative to the PrPC-expressing counterpart, the absence of PrPC modified the protein expression profile, including diminution of some components of SV recycling and fusion machinery. Subsequent quantitative RT-PCR closely reproduced proteomic data, indicating that PrPC is committed to ensuring optimal synaptic transmission by regulating genes involved in SV dynamics and neurotransmitter release. These novel molecular and cellular aspects of PrPC add insight into the underlying mechanisms for synaptic dysfunctions occurring in neurodegenerative disorders in which a compromised PrPC is likely to intervene.
Collapse
|
3
|
Sempou E, Biasini E, Pinzón-Olejua A, Harris DA, Málaga-Trillo E. Activation of zebrafish Src family kinases by the prion protein is an amyloid-β-sensitive signal that prevents the endocytosis and degradation of E-cadherin/β-catenin complexes in vivo. Mol Neurodegener 2016; 11:18. [PMID: 26860872 PMCID: PMC4748561 DOI: 10.1186/s13024-016-0076-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 01/18/2016] [Indexed: 11/25/2022] Open
Abstract
Background Prions and amyloid-β (Aβ) oligomers trigger neurodegeneration by hijacking a poorly understood cellular signal mediated by the prion protein (PrP) at the plasma membrane. In early zebrafish embryos, PrP-1-dependent signals control cell-cell adhesion via a tyrosine phosphorylation-dependent mechanism. Results Here we report that the Src family kinases (SFKs) Fyn and Yes act downstream of PrP-1 to prevent the endocytosis and degradation of E-cadherin/β-catenin adhesion complexes in vivo. Accordingly, knockdown of PrP-1 or Fyn/Yes cause similar zebrafish gastrulation phenotypes, whereas Fyn/Yes expression rescues the PrP-1 knockdown phenotype. We also show that zebrafish and mouse PrPs positively regulate the activity of Src kinases and that these have an unexpected positive effect on E-cadherin-mediated cell adhesion. Interestingly, while PrP knockdown impairs β-catenin adhesive function, PrP overexpression enhances it, thereby antagonizing its nuclear, wnt-related signaling activity and disturbing embryonic dorsoventral specification. The ability of mouse PrP to influence these events in zebrafish embryos requires its neuroprotective, polybasic N-terminus but not its neurotoxicity-associated central region. Remarkably, human Aβ oligomers up-regulate the PrP-1/SFK/E-cadherin/β-catenin pathway in zebrafish embryonic cells, mimicking a PrP gain-of-function scenario. Conclusions Our gain- and loss-of-function experiments in zebrafish suggest that PrP and SFKs enhance the cell surface stability of embryonic adherens junctions via the same complex mechanism through which they over-activate neuroreceptors that trigger synaptic damage. The profound impact of this pathway on early zebrafish development makes these embryos an ideal model to study the cellular and molecular events affected by neurotoxic PrP mutations and ligands in vivo. In particular, our finding that human Aβ oligomers activate the zebrafish PrP/SFK/E-cadherin pathway opens the possibility of using fish embryos to rapidly screen for novel therapeutic targets and compounds against prion- and Alzheimer's-related neurodegeneration. Altogether, our data illustrate PrP-dependent signals relevant to embryonic development, neuronal physiology and neurological disease. Electronic supplementary material The online version of this article (doi:10.1186/s13024-016-0076-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Emily Sempou
- Department of Biology, University of Konstanz, Constance, 78457, Germany. .,Present address: Department of Pediatrics, Yale University School of Medicine, New Haven, CT, 06520, USA.
| | - Emiliano Biasini
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, 02118, USA. .,Present address: Dulbecco Telethon Institute, Laboratory of Prions and Amyloids, Centre for Integrative Biology (CIBIO), University of Trento, 38123, Trento, Italy.
| | - Alejandro Pinzón-Olejua
- Department of Biology, University of Konstanz, Constance, 78457, Germany. .,Present address: Max PIanck Institute for Brain Research, Department of Synaptic Plasticity, 60438, Frankfurt/Main, Germany.
| | - David A Harris
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, 02118, USA.
| | - Edward Málaga-Trillo
- Department of Biology, University of Konstanz, Constance, 78457, Germany. .,Department of Biology, Universidad Peruana Cayetano Heredia, Lima 31, Perú.
| |
Collapse
|
4
|
Evaluation of improved PAMAM-G5 conjugates for gene delivery targeted to the transferrin receptor. Eur J Pharm Biopharm 2015; 94:116-22. [DOI: 10.1016/j.ejpb.2015.05.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 03/06/2015] [Accepted: 05/07/2015] [Indexed: 11/18/2022]
|
5
|
Ochs K, Málaga-Trillo E. Common themes in PrP signaling: the Src remains the same. Front Cell Dev Biol 2014; 2:63. [PMID: 25364767 PMCID: PMC4211543 DOI: 10.3389/fcell.2014.00063] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Accepted: 10/02/2014] [Indexed: 01/06/2023] Open
Abstract
The ability of the cellular prion protein (PrPC) to trigger intracellular signals appears central to neurodegeneration pathways, yet the physiological significance of such signals is rather puzzling. For instance, PrPC deregulation disrupts phenomena as diverse as synaptic transmission in mammals and cell adhesion in zebrafish. Although unrelated, the key proteins in these events -the NMDA receptor (NMDAR) and E-cadherin, respectively- are similarly modulated by the Src family kinase (SFK) Fyn. These observations highlight the importance of PrPC-mediated Fyn activation, a finding reported nearly two decades ago. Given their complex functions and regulation, SFKs may hold the key to intriguing aspects of PrP biology such as its seemingly promiscuous functions and the lack of strong phenotypes in knockout mice. Here we provide a mechanistic perspective on how SFKs might contribute to the uncertain molecular basis of neuronal PrP phenotypes affecting ion channel activity, axon myelination and olfactory function. In particular, we discuss SFK target proteins involved in these processes and the role of tyrosine phosphorylation in the regulation of their activity and cell surface expression.
Collapse
Affiliation(s)
- Katharina Ochs
- Department of Biology, University of Konstanz Konstanz, Germany
| | | |
Collapse
|
6
|
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.
Collapse
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.
| |
Collapse
|
7
|
Rouvinski A, Karniely S, Kounin M, Moussa S, Goldberg MD, Warburg G, Lyakhovetsky R, Papy-Garcia D, Kutzsche J, Korth C, Carlson GA, Godsave SF, Peters PJ, Luhr K, Kristensson K, Taraboulos A. Live imaging of prions reveals nascent PrPSc in cell-surface, raft-associated amyloid strings and webs. ACTA ACUST UNITED AC 2014; 204:423-41. [PMID: 24493590 PMCID: PMC3912534 DOI: 10.1083/jcb.201308028] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mammalian prions refold host glycosylphosphatidylinositol-anchored PrP(C) into β-sheet-rich PrP(Sc). PrP(Sc) is rapidly truncated into a C-terminal PrP27-30 core that is stable for days in endolysosomes. The nature of cell-associated prions, their attachment to membranes and rafts, and their subcellular locations are poorly understood; live prion visualization has not previously been achieved. A key obstacle has been the inaccessibility of PrP27-30 epitopes. We overcame this hurdle by focusing on nascent full-length PrP(Sc) rather than on its truncated PrP27-30 product. We show that N-terminal PrP(Sc) epitopes are exposed in their physiological context and visualize, for the first time, PrP(Sc) in living cells. PrP(Sc) resides for hours in unexpected cell-surface, slow moving strings and webs, sheltered from endocytosis. Prion strings observed by light and scanning electron microscopy were thin, micrometer-long structures. They were firmly cell associated, resisted phosphatidylinositol-specific phospholipase C, aligned with raft markers, fluoresced with thioflavin, and were rapidly abolished by anti-prion glycans. Prion strings and webs are the first demonstration of membrane-anchored PrP(Sc) amyloids.
Collapse
Affiliation(s)
- Alexander Rouvinski
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
PDK1 decreases TACE-mediated α-secretase activity and promotes disease progression in prion and Alzheimer's diseases. Nat Med 2013; 19:1124-31. [DOI: 10.1038/nm.3302] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 07/16/2013] [Indexed: 12/17/2022]
|
9
|
Didonna A. Prion protein and its role in signal transduction. Cell Mol Biol Lett 2013; 18:209-30. [PMID: 23479001 PMCID: PMC6275729 DOI: 10.2478/s11658-013-0085-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 02/18/2013] [Indexed: 11/20/2022] Open
Abstract
Prion diseases are a class of fatal neurodegenerative disorders that can be sporadic, genetic or iatrogenic. They are characterized by the unique nature of their etiologic agent: prions (PrP(Sc)). A prion is an infectious protein with the ability to convert the host-encoded cellular prion protein (PrP(C)) into new prion molecules by acting as a template. Since Stanley B. Prusiner proposed the "protein-only" hypothesis for the first time, considerable effort has been put into defining the role played by PrP(C) in neurons. However, its physiological function remains unclear. This review summarizes the major findings that support the involvement of PrP(C) in signal transduction.
Collapse
Affiliation(s)
- Alessandro Didonna
- Davee Department of Neurology, Feinberg School of Medicine Northwestern University, Chicago, IL 60611, USA.
| |
Collapse
|
10
|
Pradines E, Hernandez-Rapp J, Villa-Diaz A, Dakowski C, Ardila-Osorio H, Haik S, Schneider B, Launay JM, Kellermann O, Torres JM, Mouillet-Richard S. Pathogenic prions deviate PrP(C) signaling in neuronal cells and impair A-beta clearance. Cell Death Dis 2013; 4:e456. [PMID: 23303130 PMCID: PMC3563983 DOI: 10.1038/cddis.2012.195] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The subversion of the normal function exerted by the cellular prion protein (PrPC) in neurons by pathogenic prions is assumed to have a central role in the pathogenesis of transmissible spongiform encephalopathies. Using two murine models of prion infection, the 1C11 neuronal cell line and neurospheres, we document that prion infection is associated with the constitutive activation of signaling targets normally coupled with PrPC, including the Fyn kinase, the mitogen-associated protein kinases ERK1/2 and the CREB transcription factor. PrPC-dependent signaling overactivation in infected cells is associated with the recruitment of p38 and JNK stress-associated kinases. Downstream from CREB, prion-infected cells exhibit reduced activity of the matrix metalloprotease (MMP)-9. As MMP-9 catalyzes the degradation of the amyloid A-beta peptide, the decrease in MMP-9 activity in prion-infected cells causes a significant impairment of the clearance of A-beta, leading to its accumulation. By exploiting two 1C11-infected clones accumulating high or moderate levels of prions, we show that the prion-induced changes are correlated with the level of infectivity. Of note, a dose-dependent increase in A-beta levels was also found in the cerebrospinal fluid of mice inoculated with these infected clones. By demonstrating that pathogenic prions trigger increases in A-beta levels through the deviation of PrPC signaling, our data argue that A-beta may exacerbate prion-induced toxicity.
Collapse
Affiliation(s)
- E Pradines
- Cellules Souches, Signalisation et Prions, INSERM UMR-S747, 75006, Paris, France
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Arsenault RJ, Li Y, Potter A, Griebel PJ, Kusalik A, Napper S. Induction of ligand-specific PrP (C) signaling in human neuronal cells. Prion 2012; 6:477-88. [PMID: 22918447 DOI: 10.4161/pri.21914] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Cellular prion protein (PrP (C) ) has attracted considerable attention for its role in transmissible spongiform encephalopathies (TSEs). In spite of being a point of intense research effort critical questions still remain regarding the physiological function of PrP (C) and how these functions may change with the conversion of the protein into the infectious and pathological conformation (PrP (Sc) ). While emerging evidence suggests PrP (C/Sc) are involved in signal transduction there is little consensus on the signaling pathways associated with the normal and diseased states. The purported involvement of PrP (C) in signal transduction, and the association of TSEs with neural pathology, makes kinome analysis of human neurons an interesting and appropriate model to characterize patterns of signal transduction following activation of PrP (C) by two commonly employed experimental ligands; antibody-induced dimerization by 6H4 and the amino acids 106-126 PrP peptide fragment (PrP 106-126). Analysis of the induced kinome responses reveals distinct patterns of signaling activity following each treatment. Specifically, stimulation of human neurons with the 6H4 antibody results in alterations in mitogen activated protein kinase (MAPK) signaling pathways while the 106-126 peptide activates growth factor related signaling pathways including vascular endothelial growth factor (VEGF) signaling and the phosphoinositide-3 kinase (PI3K) pathway. These pathways were validated through independent functional assays. Collectively these results indicate that stimulation of PrP (C) with distinct ligands, even within the same cell type, results in unique patterns of signaling. While this investigation highlights the apparent functional versatility of PrP (C) as a signaling molecule and may offer insight into cellular mechanisms of TSE pathology it also emphasizes the potential dangers associated with attributing activation of specific intracellular events to particular receptors through artificial models of receptor activation.
Collapse
Affiliation(s)
- Ryan J Arsenault
- Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | | | | | | | | | | |
Collapse
|
12
|
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.
Collapse
Affiliation(s)
- Alessandro Didonna
- Laboratory of Prion Biology, Neurobiology Sector, Scuola Internazionale Superiore di Studi Avanzati (SISSA), via Bonomea 265, I-34136 Trieste, Italy.
| | | |
Collapse
|
13
|
Pradines E, Loubet D, Schneider B, Launay JM, Kellermann O, Mouillet-Richard S. CREB-dependent gene regulation by prion protein: impact on MMP-9 and beta-dystroglycan. Cell Signal 2008; 20:2050-8. [PMID: 18718863 DOI: 10.1016/j.cellsig.2008.07.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Revised: 07/18/2008] [Accepted: 07/22/2008] [Indexed: 10/21/2022]
Abstract
Corruption of the normal function of the cellular prion protein (PrP(C)) by the scrapie isoform (PrP(Sc)) emerges as a critical causal event in Transmissible Spongiform Encaphalopathies (TSE) pathogenesis. However, PrP(C) physiological role remains unclear. By exploiting the properties of the 1C11 neuroectodermal cell line, able to convert into 1C11(5-HT) serotonergic or 1C11(NE) noradrenergic neuronal cells, we assigned a signaling function to PrP(C). Here, we establish that antibody-mediated PrP(C) ligation promotes the recruitment of the cAMP responsive element binding protein (CREB) transcription factor downstream from the MAPK ERK1/2, in 1C11 precursor cells and their 1C11(5-HT) and 1C11(NE) neuronal progenies. Whatever the differentiation state of 1C11 cells, the PrP(C)-dependent CREB activation triggers Egr-1 and c-fos transcription, two immediate early genes that relay CREB's role in cell survival and proliferation as well as in neuronal plasticity. Furthermore, in 1C11-derived neuronal cells, we draw a link between the PrP(C)-CREB coupling and a transcriptional regulation of the metalloproteinase MMP-9 and its inhibitor TIMP-1, which play pivotal roles in neuronal pathophysiology. Finally, the PrP(C)-dependent control on MMP-9 impacts on the processing of the transmembrane protein, beta-dystroglycan. Taken together, our data define molecular mechanisms that likely mirror PrP(C) ubiquitous contribution to cytoprotection and its involvement in neuronal plasticity.
Collapse
Affiliation(s)
- Elodie Pradines
- Différenciation, Cellules souches et Prions, CNRS FRE2937 - INSERM U747, Institut André Lwoff, 7 rue Guy Moquet, BP8, 94801 Villejuif Cedex, France
| | | | | | | | | | | |
Collapse
|
14
|
Aguib Y, Gilch S, Krammer C, Ertmer A, Groschup MH, Schätzl HM. Neuroendocrine cultured cells counteract persistent prion infection by down-regulation of PrPc. Mol Cell Neurosci 2008; 38:98-109. [DOI: 10.1016/j.mcn.2008.02.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 01/30/2008] [Accepted: 02/13/2008] [Indexed: 11/25/2022] Open
|
15
|
Bedecs K. Cell culture models to unravel prion protein function and aberrancies in prion diseases. Methods Mol Biol 2008; 459:1-20. [PMID: 18576144 DOI: 10.1007/978-1-59745-234-2_1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
From an early stage of prion research, tissue cultures that could support and propagate the scrapie agent were sought after. The earliest attempts were explants from brains of infected mice, and their growth and morphological characteristics were compared with those from uninfected mice. Using the explant technique, several investigators reported increased cell growth in cultures established from scrapie-sick brain compared with cultures from normal mice. These are odd findings in the light of the massive neuronal cell death known to occur in scrapie-infected brains; however, the cell types responsible for the increased cell growth in the scrapie-explants most probably were not neuronal. The first successful cell culture established in this way, in which the scrapie agent was serially and continuously passaged beyond the initial explant, was in the scrapie mouse brain culture, which is still used today. This chapter describes the generation and use of chronically prion-infected cell lines as cell culture models of prion diseases. These cell lines have been crucial for the current understanding of the cell biology of both the normal (PrP(C)) and the pathogenic isoform (PrP(Sc)) of the prion protein. They also have been useful in the development of antiprion drugs, prospectively used for therapy of prion diseases, and they offer an alternative approach for transmission/infectivity assays normally performed by mouse bioassay. Cell culture models also have been used to study prion-induced cytopathological changes, which could explain the typical spongiform neurodegeneration in prion diseases.
Collapse
Affiliation(s)
- Katarina Bedecs
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| |
Collapse
|
16
|
Rivest V, Phivilay A, Julien C, Bélanger S, Tremblay C, Emond V, Calon F. Novel liposomal formulation for targeted gene delivery. Pharm Res 2007; 24:981-90. [PMID: 17385024 DOI: 10.1007/s11095-006-9224-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Accepted: 12/22/2006] [Indexed: 01/28/2023]
Abstract
PURPOSE Development of a polyethylene glycol (PEG)-stabilized immunoliposome (PSIL) formulation with high DNA content suitable for in vivo intravenous administration and targeted gene delivery. MATERIALS AND METHODS Plasmid DNA was condensed using 40% ethanol and packaged into neutral PSILs targeted to the mouse transferrin receptor using monoclonal antibodies (MAbs; clones RI7 and 8D3) attached to their PEG maleimide moieties. PSILs size was measured by quasi-elastic light scattering. The targeting capacity of the formulation was determined by transfection of mouse neuroblastoma Neuro 2A (N2A) cells with PSIL-DNA complexes conjugated with either RI7 or 8D3 MAbs. RESULTS DNA encapsulation and MAb conjugation efficiencies averaged 71 +/- 14% and 69 +/- 5% (mean +/- SD), respectively. No alteration in mean particle size (< 100 nm) or DNA leakage were found after 48 h storage in a physiological buffer, and the in vivo terminal half-life reached 23.9 h, indicating that the PSIL-DNA formulation was stable. Addition of free RI7 MAbs prevented transfection of N2A cells with PSIL-DNA complexes conjugated with either RI7 or 8D3 MAbs, confirming that the transfection was transferrin receptor-dependent. CONCLUSIONS The present data suggest that our new PSIL formulation combines molecular features required for targeted gene therapy including high DNA encapsulation efficiencies and vector-specific transient transfection capacity.
Collapse
Affiliation(s)
- Véronique Rivest
- Molecular Endocrinology and Oncology Research Center, Centre Hospitalier de l'Université Laval (CHUL) Research Center, 2705 Laurier Blvd, Quebec, QC, Canada, G1V 4G2
| | | | | | | | | | | | | |
Collapse
|
17
|
Pietri M, Caprini A, Mouillet-Richard S, Pradines E, Ermonval M, Grassi J, Kellermann O, Schneider B. Overstimulation of PrPC signaling pathways by prion peptide 106-126 causes oxidative injury of bioaminergic neuronal cells. J Biol Chem 2006; 281:28470-9. [PMID: 16864581 DOI: 10.1074/jbc.m602774200] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Transmissible spongiform encephalopathies, also called prion diseases, are characterized by neuronal loss linked to the accumulation of PrP(Sc), a pathologic variant of the cellular prion protein (PrP(C)). Although the molecular and cellular bases of PrP(Sc)-induced neuropathogenesis are not yet fully understood, increasing evidence supports the view that PrP(Sc) accumulation interferes with PrP(C) normal function(s) in neurons. In the present work, we exploit the properties of PrP-(106-126), a synthetic peptide encompassing residues 106-126 of PrP, to investigate into the mechanisms sustaining prion-associated neuronal damage. This peptide shares many physicochemical properties with PrP(Sc) and is neurotoxic in vitro and in vivo. We examined the impact of PrP-(106-126) exposure on 1C11 neuroepithelial cells, their neuronal progenies, and GT1-7 hypothalamic cells. This peptide triggers reactive oxygen species overflow, mitogen-activated protein kinase (ERK1/2), and SAPK (p38 and JNK1/2) sustained activation, and apoptotic signals in 1C11-derived serotonergic and noradrenergic neuronal cells, while having no effect on 1C11 precursor and GT1-7 cells. The neurotoxic action of PrP-(106-126) relies on cell surface expression of PrP(C), recruitment of a PrP(C)-Caveolin-Fyn signaling platform, and overstimulation of NADPH-oxidase activity. Altogether, these findings provide actual evidence that PrP-(106-126)-induced neuronal injury is caused by an amplification of PrP(C)-associated signaling responses, which notably promotes oxidative stress conditions. Distorsion of PrP(C) signaling in neuronal cells could hence represent a causal event in transmissible spongiform encephalopathy pathogenesis.
Collapse
Affiliation(s)
- Mathéa Pietri
- Différenciation Cellulaire et Prions, CNRS FRE2937, Institut André Lwoff, 7 rue Guy Môquet, 94801 Villejuif Cedex, France
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Gyllberg H, Löfgren K, Lindegren H, Bedecs K. Increased Src kinase level results in increased protein tyrosine phosphorylation in scrapie-infected neuronal cell lines. FEBS Lett 2006; 580:2603-8. [PMID: 16647068 DOI: 10.1016/j.febslet.2006.03.092] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Revised: 03/24/2006] [Accepted: 03/31/2006] [Indexed: 11/23/2022]
Abstract
We have studied how prion infection may affect the Src kinase activity in three different neuronal cell lines, ScGT1 and ScN2a, where ScGT1 were generated in our laboratory. By immunoblotting, using clone 28 - a monoclonal antibody recognizing active Src, we have found a 32+/-6.3% and 75+/-7.7% elevation in Src activity in ScGT1 and ScN2a cells, respectively, compared to uninfected cells. Immunocomplex in vitro kinase assay confirmed the increased Src activity. The increased Src kinase activity in scrapie-infected cells was further shown to correlate to an increased level of Src protein. In addition, an important increase in the protein tyrosine phosphorylation signal was observed in ScGT1 and ScN2a cells, which was further shown to be Src-dependent, as treatment with PP2 - a Src family kinase specific inhibitor, reversed the protein tyrosine phosphorylation profile. Abnormal Src-kinase activation and subsequent protein tyrosine phosphorylation may be key elements in the neuropathology of the prion diseases.
Collapse
Affiliation(s)
- Hanna Gyllberg
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 12, S-10691 Stockholm, Sweden
| | | | | | | |
Collapse
|