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Abstract
Prion diseases are neurodegenerative disorders caused by conformational conversion of the cellular prion protein (PrPC) into scrapie prion protein (PrPSc). As the main component of prion, PrPSc acts as an infectious template that recruits and converts normal cellular PrPC into its pathogenic, misfolded isoform. Intriguingly, the phenomenon of prionoid, or prion-like, spread has also been observed in many other disease-associated proteins, such as amyloid β (Aβ), tau and α-synuclein. This Cell Science at a Glance and the accompanying poster highlight recently described physiological roles of prion protein and the advanced understanding of pathogenesis of prion disease they have afforded. Importantly, prion protein may also be involved in the pathogenesis of other neurodegenerative disorders such as Alzheimer's and Parkinson's disease. Therapeutic studies of prion disease have also exploited novel strategies to combat these devastating diseases. Future studies on prion protein and prion disease will deepen our understanding of the pathogenesis of a broad spectrum of neurodegenerative conditions.
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Affiliation(s)
- Caihong Zhu
- School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Adriano Aguzzi
- Institute of Neuropathology, University Hospital Zürich, Zürich, CH-8091, Switzerland
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Ramírez-Nuñez O, Jové M, Torres P, Sol J, Fontdevila L, Romero-Guevara R, Andrés-Benito P, Ayala V, Rossi C, Boada J, Povedano M, Ferrer I, Pamplona R, Portero-Otin M. Nuclear lipidome is altered in amyotrophic lateral sclerosis: A pilot study. J Neurochem 2021; 158:482-499. [PMID: 33905537 DOI: 10.1111/jnc.15373] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 03/28/2021] [Accepted: 04/12/2021] [Indexed: 12/13/2022]
Abstract
Nucleocytosolic transport, a membrane process, is impaired in motor neurons in amyotrophic lateral sclerosis (ALS). This study analyzes the nuclear lipidome in motor neurons in ALS and examines molecular pathways linked to the major lipid alterations. Nuclei were obtained from the frozen anterior horn of the lumbar spinal cord of ALS patients and age-matched controls. Lipidomic profiles of this subcellular fraction were obtained using liquid chromatography and mass spectrometry. We validated the mechanisms behind presumable lipidomic changes by exploring ALS surrogate models including human motor neurons (derived from ALS lines and controls) subjected to oxidative stress, the hSOD-G93A transgenic mice, and samples from an independent cohort of ALS patients. Among the differential lipid species, we noted 41 potential identities, mostly belonging to phospholipids (particularly ether phospholipids, as plasmalogens), as well as diacylglycerols and triacylglycerides. Decreased expression of alkyldihydroxyacetonephosphate synthase (AGPS)-a critical peroxisomal enzyme in plasmalogen synthesis-is found in motor neuron disease models; this occurs in parallel with an increase in the expression of sterol carrier protein 2 (SCP2) mRNA in ALS and Scp2 levels in G93A transgenic mice. Further, we identified diminished expression of diacylglycerol-related enzymes, such as phospholipase C βI (PLCβI) and protein kinase CβII (PKCβII), linked to diacylglycerol metabolism. Finally, lipid droplets were recognized in the nuclei, supporting the identification of triacylglycerides as differential lipids. Our results point to the potentially pathogenic role of altered composition of nuclear membrane lipids and lipids in the nucleoplasm in the anterior horn of the spinal cord in ALS. Overall, these data support the usefulness of subcellular lipidomics applied to neurodegenerative diseases.
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Affiliation(s)
- Omar Ramírez-Nuñez
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | - Mariona Jové
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | - Pascual Torres
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | - Joaquim Sol
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain.,Institut Català de la Salut, Lleida, Spain.,Research Support Unit Lleida, Fundació Institut Universitari per a la recerca a l'Atenció Primària de Salut Jordi Gol i Gurina (IDIAPJGol), Lleida, Spain
| | - Laia Fontdevila
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | | | - Pol Andrés-Benito
- Departament of Pathology and Experimental Therapeutics, Hospital Universitari de Bellvitge, IDIBELL, Universitat de Barcelona, Hospitalet de Llobregat, Spain.,CIBERNED (Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas), Instituto Carlos III, Barcelona, Spain
| | - Victòria Ayala
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | - Chiara Rossi
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | - Jordi Boada
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | - Mònica Povedano
- Neurology Service, Hospital Universitari de Bellvitge, Barcelona, Spain
| | - Isidro Ferrer
- Departament of Pathology and Experimental Therapeutics, Hospital Universitari de Bellvitge, IDIBELL, Universitat de Barcelona, Hospitalet de Llobregat, Spain.,CIBERNED (Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas), Instituto Carlos III, Barcelona, Spain
| | - Reinald Pamplona
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | - Manuel Portero-Otin
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
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Matsubara T, Satoh K, Homma T, Nakagaki T, Yamaguchi N, Atarashi R, Sudo Y, Uezono Y, Ishibashi D, Nishida N. Prion protein interacts with the metabotropic glutamate receptor 1 and regulates the organization of Ca 2+ signaling. Biochem Biophys Res Commun 2020; 525:447-54. [PMID: 32107004 DOI: 10.1016/j.bbrc.2020.02.102] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 02/15/2020] [Indexed: 12/19/2022]
Abstract
Cellular prion protein (PrP) is a membrane protein that is highly conserved among mammals and mainly expressed on the cell surface of neurons. Despite its reported interactions with various membrane proteins, no functional studies have so far been carried out on it, and its physiological functions remain unclear. Neuronal cell death has been observed in a PrP-knockout mouse model expressing Doppel protein, suggesting that PrP might be involved in Ca2+ signaling. In this study, we evaluated the binding of PrP to metabotropic glutamate receptor 1 (mGluR1) and found that wild-type PrP (PrP-wt) and mGluR1 co-immunoprecipitated in dual-transfected Neuro-2a (N2a) cells. Fluorescence resonance energy transfer analysis revealed an energy transfer between mGluR1-Cerulean and PrP-Venus. In order to determine whether PrP can modulate mGluR1 signaling, we performed Ca2+ imaging analyses following repetitive exposure to an mGluR1 agonist. Agonist stimulation induced synchronized Ca2+ oscillations in cells coexpressing PrP-wt and mGluR1. In contrast, N2a cells expressing PrP-ΔN failed to show ligand-dependent regulation of mGluR1-Ca2+ signaling, indicating that PrP can bind to mGluR1 and modulate its function to prevent irregular Ca2+ signaling and that its N-terminal region functions as a molecular switch during Ca2+ signaling.
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Abstract
Prion diseases are progressive, incurable and fatal neurodegenerative conditions. The term 'prion' was first nominated to express the revolutionary concept that a protein could be infectious. We now know that prions consist of PrPSc, the pathological aggregated form of the cellular prion protein PrPC. Over the years, the term has been semantically broadened to describe aggregates irrespective of their infectivity, and the prion concept is now being applied, perhaps overenthusiastically, to all neurodegenerative diseases that involve protein aggregation. Indeed, recent studies suggest that prion diseases (PrDs) and protein misfolding disorders (PMDs) share some common disease mechanisms, which could have implications for potential treatments. Nevertheless, the transmissibility of bona fide prions is unique, and PrDs should be considered as distinct from other PMDs.
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Affiliation(s)
- Claudia Scheckel
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Adriano Aguzzi
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland.
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5
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Abstract
The study of life and living organisms and the way in which these interact and organize to form social communities have been central to my career. I have been fascinated by biology, neurology, and neuropathology, but also by history, sociology, and art. Certain current historical, political, and social events, some occurring proximally but others affecting people in apparently distant places, have had an impact on me. Epicurus, Seneca, and Camus shared their philosophical positions which I learned from. Many scientists from various disciplines have been exciting sources of knowledge as well. I have created a world of hypothesis and experiments but I have also got carried away by serendipity following unexpected observations. It has not been an easy path; errors and wanderings are not uncommon, and opponents close to home much more abundant than one might imagine. Ambition, imagination, resilience, and endurance have been useful in moving ahead in response to setbacks. In the end, I have enjoyed my dedication to science and I am grateful to have glimpsed beauty in it. These are brief memories of a Spanish neuropathologist born and raised in Barcelona, EU.
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Affiliation(s)
- Isidro Ferrer
- Department of Pathology and Experimental Therapeutics, University of Barcelona; Service of Pathological Anatomy, Bellvitge University Hospital; CIBERNED; Hospitalet de Llobregat, Barcelona, Spain
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Goniotaki D, Lakkaraju AKK, Shrivastava AN, Bakirci P, Sorce S, Senatore A, Marpakwar R, Hornemann S, Gasparini F, Triller A, Aguzzi A. Inhibition of group-I metabotropic glutamate receptors protects against prion toxicity. PLoS Pathog 2017; 13:e1006733. [PMID: 29176838 PMCID: PMC5720820 DOI: 10.1371/journal.ppat.1006733] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 12/07/2017] [Accepted: 11/04/2017] [Indexed: 12/29/2022] Open
Abstract
Prion infections cause inexorable, progressive neurological dysfunction and neurodegeneration. Expression of the cellular prion protein PrPC is required for toxicity, suggesting the existence of deleterious PrPC-dependent signaling cascades. Because group-I metabotropic glutamate receptors (mGluR1 and mGluR5) can form complexes with the cellular prion protein (PrPC), we investigated the impact of mGluR1 and mGluR5 inhibition on prion toxicity ex vivo and in vivo. We found that pharmacological inhibition of mGluR1 and mGluR5 antagonized dose-dependently the neurotoxicity triggered by prion infection and by prion-mimetic anti-PrPC antibodies in organotypic brain slices. Prion-mimetic antibodies increased mGluR5 clustering around dendritic spines, mimicking the toxicity of Aβ oligomers. Oral treatment with the mGluR5 inhibitor, MPEP, delayed the onset of motor deficits and moderately prolonged survival of prion-infected mice. Although group-I mGluR inhibition was not curative, these results suggest that it may alleviate the neurological dysfunctions induced by prion diseases.
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Affiliation(s)
| | | | - Amulya N. Shrivastava
- École Normale Supérieure, Institut de Biologie de l'ENS (IBENS) INSERM CNRS PSL Research University, Paris, France
- Paris-Saclay Institute of Neuroscience, CNRS, Gif-sur-Yvette, France
| | - Pamela Bakirci
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Silvia Sorce
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Assunta Senatore
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | | | - Simone Hornemann
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | | | - Antoine Triller
- École Normale Supérieure, Institut de Biologie de l'ENS (IBENS) INSERM CNRS PSL Research University, Paris, France
| | - Adriano Aguzzi
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
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Ansoleaga B, Garcia-Esparcia P, Llorens F, Hernández-Ortega K, Carmona Tech M, Antonio Del Rio J, Zerr I, Ferrer I. Altered Mitochondria, Protein Synthesis Machinery, and Purine Metabolism Are Molecular Contributors to the Pathogenesis of Creutzfeldt-Jakob Disease. J Neuropathol Exp Neurol 2016; 75:755-769. [PMID: 27297670 DOI: 10.1093/jnen/nlw048] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Neuron loss, synaptic decline, and spongiform change are the hallmarks of sporadic Creutzfeldt-Jakob disease (sCJD), and may be related to deficiencies in mitochondria, energy metabolism, and protein synthesis. To investigate these relationships, we determined the expression levels of genes encoding subunits of the 5 protein complexes of the electron transport chain, proteins involved in energy metabolism, nucleolar and ribosomal proteins, and enzymes of purine metabolism in frontal cortex samples from 15 cases of sCJD MM1 and age-matched controls. We also assessed the protein expression levels of subunits of the respiratory chain, initiation and elongation translation factors of protein synthesis, and localization of selected mitochondrial components. We identified marked, generalized alterations of mRNA and protein expression of most subunits of all 5 mitochondrial respiratory chain complexes in sCJD cases. Expression of molecules involved in protein synthesis and purine metabolism were also altered in sCJD. These findings point to altered mRNA and protein expression of components of mitochondria, protein synthesis machinery, and purine metabolism as components of the pathogenesis of CJD.
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Affiliation(s)
- Belén Ansoleaga
- From the Institute of Neuropathology, Service of Pathologic Anatomy, Hospital Universitari de Bellvitge, Hospitalet de Llobregat, Spain (BA, PG-E, KH-O, MC, IF); CIBERNED, Network Centre for Biomedical Research of Neurodegenerative Diseases, Institute Carlos III, Spain (PG-E, KH-O, MC, JAR, IF); Department of Neurology, Clinical Dementia Center, University Medical School, Georg-August University and German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany (FL, IZ); Molecular and Cellular Neurobiotechnology, Institute of Bioengineering of Catalonia (IBEC), Parc Científic de Barcelona, Department of Cell Biology, University of Barcelona, Barcelona, Spain (JAR); and Department of Pathology and Experimental Therapeutics, University of Barcelona, L'Hospitalet de Llobregat, Spain (IF)
| | - Paula Garcia-Esparcia
- From the Institute of Neuropathology, Service of Pathologic Anatomy, Hospital Universitari de Bellvitge, Hospitalet de Llobregat, Spain (BA, PG-E, KH-O, MC, IF); CIBERNED, Network Centre for Biomedical Research of Neurodegenerative Diseases, Institute Carlos III, Spain (PG-E, KH-O, MC, JAR, IF); Department of Neurology, Clinical Dementia Center, University Medical School, Georg-August University and German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany (FL, IZ); Molecular and Cellular Neurobiotechnology, Institute of Bioengineering of Catalonia (IBEC), Parc Científic de Barcelona, Department of Cell Biology, University of Barcelona, Barcelona, Spain (JAR); and Department of Pathology and Experimental Therapeutics, University of Barcelona, L'Hospitalet de Llobregat, Spain (IF)
| | - Franc Llorens
- From the Institute of Neuropathology, Service of Pathologic Anatomy, Hospital Universitari de Bellvitge, Hospitalet de Llobregat, Spain (BA, PG-E, KH-O, MC, IF); CIBERNED, Network Centre for Biomedical Research of Neurodegenerative Diseases, Institute Carlos III, Spain (PG-E, KH-O, MC, JAR, IF); Department of Neurology, Clinical Dementia Center, University Medical School, Georg-August University and German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany (FL, IZ); Molecular and Cellular Neurobiotechnology, Institute of Bioengineering of Catalonia (IBEC), Parc Científic de Barcelona, Department of Cell Biology, University of Barcelona, Barcelona, Spain (JAR); and Department of Pathology and Experimental Therapeutics, University of Barcelona, L'Hospitalet de Llobregat, Spain (IF)
| | - Karina Hernández-Ortega
- From the Institute of Neuropathology, Service of Pathologic Anatomy, Hospital Universitari de Bellvitge, Hospitalet de Llobregat, Spain (BA, PG-E, KH-O, MC, IF); CIBERNED, Network Centre for Biomedical Research of Neurodegenerative Diseases, Institute Carlos III, Spain (PG-E, KH-O, MC, JAR, IF); Department of Neurology, Clinical Dementia Center, University Medical School, Georg-August University and German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany (FL, IZ); Molecular and Cellular Neurobiotechnology, Institute of Bioengineering of Catalonia (IBEC), Parc Científic de Barcelona, Department of Cell Biology, University of Barcelona, Barcelona, Spain (JAR); and Department of Pathology and Experimental Therapeutics, University of Barcelona, L'Hospitalet de Llobregat, Spain (IF)
| | - Margarita Carmona Tech
- From the Institute of Neuropathology, Service of Pathologic Anatomy, Hospital Universitari de Bellvitge, Hospitalet de Llobregat, Spain (BA, PG-E, KH-O, MC, IF); CIBERNED, Network Centre for Biomedical Research of Neurodegenerative Diseases, Institute Carlos III, Spain (PG-E, KH-O, MC, JAR, IF); Department of Neurology, Clinical Dementia Center, University Medical School, Georg-August University and German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany (FL, IZ); Molecular and Cellular Neurobiotechnology, Institute of Bioengineering of Catalonia (IBEC), Parc Científic de Barcelona, Department of Cell Biology, University of Barcelona, Barcelona, Spain (JAR); and Department of Pathology and Experimental Therapeutics, University of Barcelona, L'Hospitalet de Llobregat, Spain (IF)
| | - José Antonio Del Rio
- From the Institute of Neuropathology, Service of Pathologic Anatomy, Hospital Universitari de Bellvitge, Hospitalet de Llobregat, Spain (BA, PG-E, KH-O, MC, IF); CIBERNED, Network Centre for Biomedical Research of Neurodegenerative Diseases, Institute Carlos III, Spain (PG-E, KH-O, MC, JAR, IF); Department of Neurology, Clinical Dementia Center, University Medical School, Georg-August University and German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany (FL, IZ); Molecular and Cellular Neurobiotechnology, Institute of Bioengineering of Catalonia (IBEC), Parc Científic de Barcelona, Department of Cell Biology, University of Barcelona, Barcelona, Spain (JAR); and Department of Pathology and Experimental Therapeutics, University of Barcelona, L'Hospitalet de Llobregat, Spain (IF)
| | - Inga Zerr
- From the Institute of Neuropathology, Service of Pathologic Anatomy, Hospital Universitari de Bellvitge, Hospitalet de Llobregat, Spain (BA, PG-E, KH-O, MC, IF); CIBERNED, Network Centre for Biomedical Research of Neurodegenerative Diseases, Institute Carlos III, Spain (PG-E, KH-O, MC, JAR, IF); Department of Neurology, Clinical Dementia Center, University Medical School, Georg-August University and German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany (FL, IZ); Molecular and Cellular Neurobiotechnology, Institute of Bioengineering of Catalonia (IBEC), Parc Científic de Barcelona, Department of Cell Biology, University of Barcelona, Barcelona, Spain (JAR); and Department of Pathology and Experimental Therapeutics, University of Barcelona, L'Hospitalet de Llobregat, Spain (IF)
| | - Isidro Ferrer
- From the Institute of Neuropathology, Service of Pathologic Anatomy, Hospital Universitari de Bellvitge, Hospitalet de Llobregat, Spain (BA, PG-E, KH-O, MC, IF); CIBERNED, Network Centre for Biomedical Research of Neurodegenerative Diseases, Institute Carlos III, Spain (PG-E, KH-O, MC, JAR, IF); Department of Neurology, Clinical Dementia Center, University Medical School, Georg-August University and German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany (FL, IZ); Molecular and Cellular Neurobiotechnology, Institute of Bioengineering of Catalonia (IBEC), Parc Científic de Barcelona, Department of Cell Biology, University of Barcelona, Barcelona, Spain (JAR); and Department of Pathology and Experimental Therapeutics, University of Barcelona, L'Hospitalet de Llobregat, Spain (IF).
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Abstract
Background: Acute kidney injury (AKI) is a condition that leads to a rapid deterioration of renal function associated with impairment to maintain electrolyte and acid balance, and, if left untreated, ultimately irreversible kidney damage and renal necrosis. There are a number of causes that can trigger AKI, ranging from underlying conditions as well as trauma and surgery. Specifically, the global rise in surgical procedures led to a substantial increase of AKI incidence rates, which in turn impacts on mortality rates, quality of life and economic costs to the healthcare system. However, no effective therapy for AKI exists. Current approaches, such as pharmacological intervention, help in alleviating symptoms in slowing down the progression, but do not prevent or reverse AKI-induced organ damage. Methods: An in-depth understanding of the molecular machinery involved in and modulated by AKI induction and progression is necessary to specifically pharmacologically target key molecules. A major hurdle to devise a successful strategy is the multifactorial and complex nature of the disorder itself, whereby the activation of a number of seemingly independent molecular pathways in the kidney leads to apoptotic and necrotic events. Results: The renin-angiotensin-aldosterone-system (RAAS) axis appears to be a common element, leading to downstream events such as triggers of immune responses via the NFB pathway. Other pathways intricately linked with AKI-induction and progression are the tumor necrosis factor alpha (TNF α) and transforming growth factor beta (TGF β) signaling cascades, as well as a number of other modulators. Surprisingly, it has been shown that the involvement of the glutamatergic axis, believed to be mainly a component of the neurological system, is also a major contributor. Conclusions: Here we address the current understanding of the molecular pathways evoked in AKI, their interplay, and the potential to pharmacologically intervene in the effective prevention and/or progression of AKI.
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Affiliation(s)
- Holger Husi
- BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK.
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Machado CF, Beraldo FH, Santos TG, Bourgeon D, Landemberger MC, Roffé M, Martins VR. Disease-associated mutations in the prion protein impair laminin-induced process outgrowth and survival. J Biol Chem 2012; 287:43777-88. [PMID: 23132868 DOI: 10.1074/jbc.m112.428235] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Prions, the agents of transmissible spongiform encephalopathies, require the expression of prion protein (PrP(C)) to propagate disease. PrP(C) is converted into an abnormal insoluble form, PrP(Sc), that gains neurotoxic activity. Conversely, clinical manifestations of prion disease may occur either before or in the absence of PrP(Sc) deposits, but the loss of normal PrP(C) function contribution for the etiology of these diseases is still debatable. Prion disease-associated mutations in PrP(C) represent one of the best models to understand the impact of PrP(C) loss-of-function. PrP(C) associates with various molecules and, in particular, the interaction of PrP(C) with laminin (Ln) modulates neuronal plasticity and memory formation. To assess the functional alterations associated with PrP(C) mutations, wild-type and mutated PrP(C) proteins were expressed in a neural cell line derived from a PrP(C)-null mouse. Treatment with the laminin γ1 chain peptide (Ln γ1), which mimics the Ln binding site for PrP(C), increased intracellular calcium in cells expressing wild-type PrP(C), whereas a significantly lower response was observed in cells expressing mutated PrP(C) molecules. The Ln γ1 did not promote process outgrowth or protect against staurosporine-induced cell death in cells expressing mutated PrP(C) molecules in contrast to cells expressing wild-type PrP(C). The co-expression of wild-type PrP(C) with mutated PrP(C) molecules was able to rescue the Ln protective effects, indicating the lack of negative dominance of PrP(C) mutated molecules. These results indicate that PrP(C) mutations impair process outgrowth and survival mediated by Ln γ1 peptide in neural cells, which may contribute to the pathogenesis of genetic prion diseases.
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Affiliation(s)
- Cleiton F Machado
- International Research Center, A. C. Camargo Hospital, and National Institute for Translational Neuroscience (CNPq/MCT/FAPESP), São Paulo 01508-010, Brazil
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10
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Sisó S, González L, Blanco R, Chianini F, Reid HW, Jeffrey M, Ferrer I. Neuropathological changes correlate temporally but not spatially with selected neuromodulatory responses in natural scrapie. Neuropathol Appl Neurobiol 2011; 37:484-99. [PMID: 21114681 DOI: 10.1111/j.1365-2990.2010.01152.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM Neuropathological changes classically associated with sheep scrapie do not always correlate with clinical disease. We aimed to determine if selected neuromodulatory responses were altered during the course of the infection as it has been described in Creutzfeldt-Jakob disease and experimental bovine spongiform encephalopathy. METHODS Hemi-brains from healthy sheep and natural scrapie cases at two stages of infection were examined for biochemical alterations related to the expression of type I metabotropic glutamatergic receptors (mGluR(1) ) and type I adenosine receptors I (A(1) R), and of selected downstream intermediate signalling targets. Immunohistochemistry for different scrapie-related neuropathological changes was performed in the contralateral hemi-brains. RESULTS PrP(d) deposition, spongiform change, astrocytosis and parvalbumin expression were significantly altered in brains from clinically affected sheep compared with preclinical cases and negative controls; the latter also showed significantly higher immunoreactivity for synaptophysin than clinical cases. Between clinically affected and healthy sheep, no differences were found in the protein levels of mGluR(1) , while phospholipase Cβ1 expression in terminally ill sheep was increased in some brain areas but decreased in others. Adenyl cyclase 1 and A(1) R levels were significantly lower in various brain areas of affected sheep. No abnormal biochemical expression levels of these markers were found in preclinically infected sheep. CONCLUSIONS These findings point towards an involvement of mGluR(1) and A(1) R downstream pathways in natural scrapie. While classical prion disease lesions and neuromodulatory responses converge in some affected regions, they do not do so in others suggesting that there are independent regulatory factors for distinct degenerative and neuroprotective responses.
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Affiliation(s)
- S Sisó
- Veterinary Laboratories Agency Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, UK.
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11
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Castillo CA, León DA, Ballesteros-Yáñez I, Iglesias I, Martín M, Albasanz JL. Glutamate differently modulates metabotropic glutamate receptors in neuronal and glial cells. Neurochem Res 2010; 35:1050-63. [PMID: 20309728 DOI: 10.1007/s11064-010-0154-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2010] [Indexed: 12/17/2022]
Abstract
Glutamate is an excitatory neurotransmitter implicated in learning and memory processes, but at high concentrations it acts as an excitotoxin causing degeneration and neuronal death. The aim of this work was to determine the excitotoxic effect of glutamate and the regulation of metabotropic glutamate receptors (mGluR) during excitotoxicity in neurons and C6 glioma cells. Results show that glutamate causes excitotoxic damage only in cortical neurons. Loss of cell viability in neurons was glutamate concentration- and time-dependent. Total mGluR levels were significantly reduced in these cells when exposed to glutamate. However, in C6 cells, which have been used as a model of glial cells, these receptors were regulated in a biphasic manner, decreased after 6 h, and increased after 24/48 h of treatment. Results show a cell dependent mGluR regulation by glutamate exposure which could mediate the vulnerability or not to glutamate mediated excitotoxicity.
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Albasanz JL, Rodríguez A, Ferrer I, Martín M. Up-regulation of adenosine A1 receptors in frontal cortex from Pick's disease cases. Eur J Neurosci 2007; 26:3501-8. [DOI: 10.1111/j.1460-9568.2007.05965.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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13
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Moleres FJ, Velayos JL. The neurochemical nature of PrPc-containing cells in the rat brain. Brain Res 2007; 1174:143-51. [PMID: 17854776 DOI: 10.1016/j.brainres.2007.07.069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Revised: 07/17/2007] [Accepted: 07/20/2007] [Indexed: 01/15/2023]
Abstract
The cellular prion protein (PrP(C)) is a membrane-bound glycoprotein abundantly expressed in neurons and glial cells within the CNS. The scrapie prion protein (PrP(Sc)) is a conformationally altered isoform of PrP(C) that is responsible for prion diseases, also termed transmissible spongiform encephalopathies (TSE), a group of neurodegenerative diseases that affect a wide variety of mammal species, including humans. The presence of the cellular isoform of PrP is necessary for the establishment and further evolution of prion diseases and the physiological conditions where PrP(C) is present seems to modulate the alterations in TSE. In this work, the presence of PrP(C) in GABAergic, glutamatergic, nitrergic, cholinergic, serotoninergic and orexinergic populations of cells within the rat brain is examined. Our observations show that PrP(C) is widely expressed in a subset of neurons that contain markers of inhibitory populations of cells throughout the rat brain. The presence of PrP(C) in other cells types containing important neurotransmitters for the overall brain function is congruent with the imbalances reported for some of them in TSE. Within the cerebral cortex, PrP(C) is scarcely located in a subset of cells expressing the laminin receptor precursor (LRP) to such a low extent that suggests that other LRP-independent mechanisms actively participate during the pathogenic process. Taken together, our data demonstrate that investigation of the chemical partners of PrP(C) within cells gives a rational basis for the interpretation of the histopathological alterations in TSE and might help analyze some pathogenic mechanisms of PrP(Sc).
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Affiliation(s)
- Francisco J Moleres
- Department of Anatomy, Faculty of Medicine, University of Navarra, Irunlarrea s/n, 31080 Pamplona, Spain.
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Rodríguez A, Martín M, Albasanz JL, Barrachina M, Espinosa JC, Torres JM, Ferrer I. Group I mGluR signaling in BSE-infected bovine-PrP transgenic mice. Neurosci Lett 2006; 410:115-20. [PMID: 17084974 DOI: 10.1016/j.neulet.2006.09.084] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 09/22/2006] [Accepted: 09/22/2006] [Indexed: 11/22/2022]
Abstract
Abnormalities of synapses and impaired synaptic transmission appear to be crucial in the pathogenesis of prion diseases. Excitotoxic mechanisms have been postulated as a major cause of neurodegeneration in these conditions. In this line, previous studies have shown abnormal group 1 metabotropic glutamate receptor signaling in Creutzfeldt-Jakob disease (CJD). In the present study, we have examined this pathway by western blotting in the cerebral cortex of bovine-spongiform encephalopathy (BSE)-infected bovine-PrP transgenic mice at different days post-inoculation (dpi). Activation of post-synaptic metabotropic glutamate receptor 1 (mGluR1) promotes phospholipase Cbeta1 (PLCbeta1) activation which may activate, in turn, protein kinase C (PKC), which regulates gene expression. Densitometric analysis of the western blot bands revealed no differences in the protein levels of (mGluR1) through time, but demonstrated decreased levels of PLCbeta1 and protein kinase C delta (nPKCdelta) at 270dpi, at the time when mice showed neurological deficits accompanied by neuropathological changes and PrPres deposition in the brain. The present results show, for the first time impairment of the mGluR1/PLCbeta1/PKCdelta pathway signaling with disease-progression in a murine model of BSE.
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Affiliation(s)
- Agustín Rodríguez
- Institut de Neuropatologia, Servei Anatomia Patològica, IDIBELL-Hospital Universitari de Bellvitge, Spain
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Rodríguez A, Martín M, Albasanz JL, Barrachina M, Espinosa JC, Torres JM, Ferrer I. Adenosine A1 Receptor Protein Levels and Activity Is Increased in the Cerebral Cortex in Creutzfeldt-Jakob Disease and in Bovine Spongiform Encephalopathy-Infected Bovine-PrP Mice. J Neuropathol Exp Neurol 2006; 65:964-75. [PMID: 17021401 DOI: 10.1097/01.jnen.0000235120.59935.f5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Prion diseases are characterized by neuronal loss, astrocytic gliosis, spongiform change, and abnormal protease-resistant prion protein (PrP) deposition. Creutzfeldt-Jakob disease (CJD) is the most prevalent human prion disease, whereas scrapie and bovine spongiform encephalopathy (BSE) are the most common animal prion diseases. Several candidates have been proposed as mediators of degeneration in prion diseases, one of them glutamate. Recent studies have shown reduced metabotropic glutamate receptor/phospholipase C signaling in the cerebral cortex in CJD, suggesting that this important neuromodulator and neuroprotector pathway is attenuated in CJD. Adenosine is involved in the regulation of different metabolic processes under physiological and pathologic conditions. Adenosine function is mediated by adenosine receptors, which are categorized into 4 types: A1, A2A, A2B, and A3. A1Rs are G-protein-coupled receptors that induce the inhibition of adenylyl cyclase activity. The most dramatic inhibitory actions of adenosine receptors are on the glutamatergic system. For these reasons, we examined the levels of A1Rs in the frontal cortex of 12 patients with CJD and 6 age-matched controls and in BSE-infected bovine-PrP transgenic mice (BoPrP-Tg110 mice) at different postincubation times to address modifications in A1Rs with disease progression. A significant increase in the protein levels of A1Rs was found in the cerebral cortex in CJD and in the murine BSE model at advanced stages of the disease and coincidental with the appearance of PrP expression. In addition, the activity of A1Rs was analyzed by in vitro assays with isolated membranes of the frontal cortex in CJD. Increased activity of the receptor, as revealed by the decreased forskolin-stimulated cAMP production in response to the A1R agonists cyclohexyl adenosine and cyclopentyl adenosine, was observed in CJD cases when compared with controls. Finally, mRNA A1R levels were similar in CJD and control cases, thus suggesting abnormal A1R turnover or dysregulation of raft-associated signaling pathways in CJD. These results show, for the first time, sensitization of A1Rs in prion diseases.
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Affiliation(s)
- Agustín Rodríguez
- Institut de Neuropatologia, Servei Anatomia Patològica, IDIBELL-Hospital Universitari de Bellvitge, Universitat de Barcelona, 08907 Hospitalet de Llobregat, Spain
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