title: Proteomic Profiling of Cranial (Superior) Cervical Ganglia Reveals Beta-Amyloid and Ubiquitin Proteasome System Perturbations in an Equine Multiple System Neuropathy.
abstract: Equine grass sickness (EGS) is an acute, predominantly fatal, multiple system neuropathy of grazing horses with reported incidence rates of ∼2%. An apparently identical disease occurs in multiple species, including but not limited to cats, dogs, and rabbits. Although the precise etiology remains unclear, ultrastructural findings have suggested that the primary lesion lies in the glycoprotein biosynthetic pathway of specific neuronal populations. The goal of this study was therefore to identify the molecular processes underpinning neurodegeneration in EGS. Here, we use a bottom-up approach beginning with the application of modern proteomic tools to the analysis of cranial (superior) cervical ganglion (CCG, a consistently affected tissue) from EGS-affected patients and appropriate control cases postmortem. In what appears to be the proteomic application of modern proteomic tools to equine neuronal tissues and/or to an inherent neurodegenerative disease of large animals (not a model of human disease), we identified 2,311 proteins in CCG extracts, with 320 proteins increased and 186 decreased by greater than 20% relative to controls. Further examination of selected proteomic candidates by quantitative fluorescent Western blotting (QFWB) and subcellular expression profiling by immunohistochemistry highlighted a previously unreported dysregulation in proteins commonly associated with protein misfolding/aggregation responses seen in a myriad of human neurodegenerative conditions, including but not limited to amyloid precursor protein (APP), microtubule associated protein (Tau), and multiple components of the ubiquitin proteasome system (UPS). Differentially expressed proteins eligible for in silico pathway analysis clustered predominantly into the following biofunctions: (1) diseases and disorders, including; neurological disease and skeletal and muscular disorders and (2) molecular and cellular functions, including cellular assembly and organization, cell-to-cell signaling and interaction (including epinephrine, dopamine, and adrenergic signaling and receptor function), and small molecule biochemistry. Interestingly, while the biofunctions identified in this study may represent pathways underpinning EGS-induced neurodegeneration, this is also the first demonstration of potential molecular conservation (including previously unreported dysregulation of the UPS and APP) spanning the degenerative cascades from an apparently unrelated condition of large animals, to small animal models with altered neuronal vulnerability, and human neurological conditions. Importantly, this study highlights the feasibility and benefits of applying modern proteomic techniques to veterinary investigations of neurodegenerative processes in diseases of large animals.
authors.affiliation: From the Veterinary Clinical Sciences and bruce.mcgorum@ed.ac.uk T.M.Wishart@ed.ac.uk.
authors.forename: Bruce C
authors.initials: BC
authors.lastname: McGorum
authors.affiliation: From the Veterinary Clinical Sciences and.
authors.forename: R Scott
authors.initials: RS
authors.lastname: Pirie
authors.affiliation: §Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, UK;
authors.forename: Samantha L
authors.initials: SL
authors.lastname: Eaton
authors.affiliation: From the Veterinary Clinical Sciences and.
authors.forename: John A
authors.initials: JA
authors.lastname: Keen
authors.affiliation: §Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, UK;
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Cumyn
authors.affiliation: §Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, UK;
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Arnott
authors.affiliation: FingerPrints: Proteomics Facility, School of Life Sciences, University of Dundee, Dundee, UK;
authors.forename: Wenzhang
authors.initials: W
authors.lastname: Chen
authors.affiliation: FingerPrints: Proteomics Facility, School of Life Sciences, University of Dundee, Dundee, UK;
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Lamont
authors.affiliation: §Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, UK;
authors.forename: Laura C
authors.initials: LC
authors.lastname: Graham
authors.affiliation: §Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, UK;
authors.forename: Maica
authors.initials: M
authors.lastname: Llavero Hurtado
authors.affiliation: From the Veterinary Clinical Sciences and.
authors.forename: Alan
authors.initials: A
authors.lastname: Pemberton
authors.affiliation: §Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, UK; Euan MacDonald Centre for Motor Neuron Disease Research, University of Edinburgh, Edinburgh, UK bruce.mcgorum@ed.ac.uk T.M.Wishart@ed.ac.uk.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Wishart
mesh_terms: D016564:Amyloid beta-Protein Precursor / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D005260:Female; D017950:Ganglia, Sensory / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D063990:Gene Ontology; D006734:Horse Diseases / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D006736:Horses; D008297:Male; D058977:Molecular Sequence Annotation; D019636:Neurodegenerative Diseases / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D040901:Proteomics; D057165:Proteostasis Deficiencies / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D025801:Ubiquitin / Q000235:genetics* / Q000378:metabolism; D016875:tau Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D016564:Amyloid beta-Protein Precursor; D025801:Ubiquitin; D016875:tau Proteins; D046988:Proteasome Endopeptidase Complex