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Angelica Nakagawa Lima, Ronaldo Junio de Oliveira, Antônio Sérgio Kimus Braz, Maurício Garcia de Souza Costa, David Perahia, Luis Paulo Barbour Scott
There are two different prion conformations: (1) the cellular natural (PrPC ) and (2) the scrapie (PrPSc ), an infectious form that tends to aggregate under specific conditions. PrPC and PrPSc are widely different regarding secondary and tertiary structures. PrPSc contains more and longer β-strands compared to PrPC . The lack of solved PrPSc structures precludes a proper understanding of the mechanisms related to the transition between cellular and scrapie forms, as well as the aggregation process. In order to investigate the conformational transition between PrPC and PrPSc , we applied MDeNM (molecular dynamics with excited normal modes), an enhanced sampling simulation technique that has been recently developed to probe large structural changes...
March 15, 2018: European Biophysics Journal: EBJ
Maria Letizia Barreca, Nunzio Iraci, Silvia Biggi, Violetta Cecchetti, Emiliano Biasini
Prion diseases are associated with the conversion of the cellular prion protein (PrPC ), a glycoprotein expressed at the surface of a wide variety of cell types, into a misfolded conformer (the scrapie form of PrP, or PrPSc ) that accumulates in brain tissues of affected individuals. PrPSc is a self-catalytic protein assembly capable of recruiting native conformers of PrPC , and causing their rearrangement into new PrPSc molecules. Several previous attempts to identify therapeutic agents against prion diseases have targeted PrPSc , and a number of compounds have shown potent anti-prion effects in experimental models...
March 7, 2018: Pathogens
Paola Sacchi, Roberto Rasero, Giuseppe Ru, Eleonora Aiassa, Silvia Colussi, Francesco Ingravalle, Simone Peletto, Maria Gabriella Perrotta, Stefano Sartore, Dominga Soglia, Pierluigi Acutis
The European Union has implemented breeding programmes to increase scrapie resistance in sheep. A similar approach can be applied also in goats since the K222 allele provides a level of resistance equivalent to that of ARR in sheep. The European Food Safety Authority stated that breeding for resistance could be offered as an option for Member States to control classical scrapie in goats. We assessed the impact of different breeding strategies on PRNP genotype frequencies using a mathematical model that describes in detail the evolution of K222 in two goat breeds, Chamois Coloured and Saanen...
March 6, 2018: Veterinary Research
M U Cinar, D A Schneider, D F Waldron, K I O'Rourke, S N White
Scrapie is a transmissible spongiform encephalopathy of sheep and goats, and scrapie eradication programs in many parts of the world rely on strong genetic resistance to classical scrapie in sheep. However, the utility of putative resistance alleles in goats has been a focus of research because goats can transmit scrapie to sheep and may serve as a scrapie reservoir. Prior work showed that disease-free survival time was significantly extended in orally inoculated goats singly heterozygous for prion amino acid substitutions S146 or K222, but average durations were only around 3 years post-inoculation...
March 2018: Veterinary Journal
David Huyben, Sofia Boqvist, Volkmar Passoth, Lena Renström, Ulrika Allard Bengtsson, Olivier Andréoletti, Anders Kiessling, Torbjörn Lundh, Ivar Vågsholm
Yeasts can be used to convert organic food wastes to protein-rich animal feed in order to recapture nutrients. However, the reuse of animal-derived waste poses a risk for the transmission of infectious prions that can cause neurodegeneration and fatality in humans and animals. The aim of this study was to investigate the ability of yeasts to reduce prion activity during the biotransformation of waste substrates-thereby becoming a biosafety hurdle in such a circular food system. During pre-screening, 30 yeast isolates were spiked with Classical Scrapie prions and incubated for 72 h in casein substrate, as a waste substitute...
February 8, 2018: Acta Veterinaria Scandinavica
Carolina Sánchez-López, Claudio O Fernández, Liliana Quintanar
The cellular prion protein (PrPC) is a copper binding protein that undergoes post-translational modifications, such as endoproteolytic alpha cleavage, which occurs in the vicinity of the His111 Cu binding site. Alpha cleavage processing of PrPC is considered to be neuroprotective since the cleavage site is located in a region that is key to the conversion of PrPC into the infectious scrapie isoform (PrPSc), yielding a membrane bound C1 fragment of PrPC that still contains His111. In this work, we use hPrP(111-115) fragment as a model peptide to evaluate the impact of alpha cleavage processing of PrPC in its ability to coordinate Cu(ii) ions at His111...
February 8, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Holger Wille, Jesús R Requena
PrPSc (scrapie isoform of the prion protein) prions are the infectious agent behind diseases such as Creutzfeldt-Jakob disease in humans, bovine spongiform encephalopathy in cattle, chronic wasting disease in cervids (deer, elk, moose, and reindeer), as well as goat and sheep scrapie. PrPSc is an alternatively folded variant of the cellular prion protein, PrPC, which is a regular, GPI-anchored protein that is present on the cell surface of neurons and other cell types. While the structure of PrPC is well studied, the structure of PrPSc resisted high-resolution determination due to its general insolubility and propensity to aggregate...
February 7, 2018: Pathogens
Maria Domenica Pintore, Walter Mignone, Giovanni Di Guardo, Sandro Mazzariol, Marco Ballardini, Caterina Lucia Florio, Maria Goria, Angelo Romano, Santo Caracappa, Federica Giorda, Laura Serracca, Alessandra Pautasso, Cristiana Tittarelli, Antonio Petrella, Giuseppe Lucifora, Fabio Di Nocera, Barbara Degli Uberti, Cristiano Corona, Cristina Casalone, Barbara Iulini
  We summarized the neuropathologic findings in 60 cetaceans stranded along the Italian coastline from 2002 to 2014. The following neuropathologic changes were detected in 45% (27/60) of animals: nonsuppurative encephalitides (30%, 18/60), nonspecific lesions (12%, 7/60), suppurative encephalitis (2%, 1/60), and neoplasm (2%, 1/60). No histologic lesions were found in 47% (28/60) of the specimens. Five (8%, 5/60) samples were unsuitable for analysis. Analysis with PCR detected Brucella spp., morbillivirus, and Toxoplasma gondii infection in one, six, and seven individuals, respectively...
January 25, 2018: Journal of Wildlife Diseases
C R Seed, P E Hewitt, R Y Dodd, F Houston, L Cervenakova
Transmissible spongiform encephalopathies (TSEs) are untreatable, fatal neurologic diseases affecting mammals. Human disease forms include sporadic, familial and acquired Creutzfeldt-Jakob disease (CJD). While sporadic CJD (sCJD) has been recognized for near on 100 years, variant CJD (vCJD) was first reported in 1996 and is the result of food-borne transmission of the prion of bovine spongiform encephalopathy (BSE, 'mad cow disease'). Currently, 230 vCJD cases have been reported in 12 countries, the majority in the UK (178) and France (27)...
January 22, 2018: Vox Sanguinis
Patricia L A Leighton, Nathan J Nadolski, Adam Morrill, Trevor J Hamilton, W Ted Allison
The misfolding of cellular prion protein (PrPC) to form PrP Scrapie (PrPSc) is an exemplar of toxic gain-of-function mechanisms inducing propagated protein misfolding and progressive devastating neurodegeneration. Despite this, PrPC function in the brain is also reduced and subverted during prion disease progression; thus understanding the normal function of PrPC in healthy brains is key. Disrupting PrPC in mice has led to a myriad of controversial functions that sometimes map onto disease symptoms, including a proposed role in memory or learning...
January 22, 2018: Biology Open
Robert C C Mercer, Nathalie Daude, Lyudmyla Dorosh, Ze-Lin Fu, Charles E Mays, Hristina Gapeshina, Serene L Wohlgemuth, Claudia Y Acevedo-Morantes, Jing Yang, Neil R Cashman, Michael B Coulthart, Dawn M Pearson, Jeffrey T Joseph, Holger Wille, Jiri G Safar, Gerard H Jansen, Maria Stepanova, Brian D Sykes, David Westaway
To explore pathogenesis in a young Gerstmann-Sträussler-Scheinker Disease (GSS) patient, the corresponding mutation, an eight-residue duplication in the hydrophobic region (HR), was inserted into the wild type mouse PrP gene. Transgenic (Tg) mouse lines expressing this mutation (Tg.HRdup) developed spontaneous neurologic syndromes and brain extracts hastened disease in low-expressor Tg.HRdup mice, suggesting de novo formation of prions. While Tg.HRdup mice exhibited spongiform change, PrP aggregates and the anticipated GSS hallmark of a proteinase K (PK)-resistant 8 kDa fragment deriving from the center of PrP, the LGGLGGYV insertion also imparted alterations in PrP's unstructured N-terminus, resulting in a 16 kDa species following thermolysin exposure...
January 16, 2018: PLoS Pathogens
Sandra Pritzkow, Rodrigo Morales, Adam Lyon, Luis Concha-Marambio, Akihiko Urayama, Claudio Soto
Prion diseases are a group of fatal neurodegenerative diseases associated with a protein-based infectious agent, termed prion. Compelling evidence suggests that natural transmission of prion diseases is mediated by environmental contamination with infectious prions. We hypothesized that several natural and man-made materials, commonly found in the environments of wild and captive animals, can bind prions and may act as vectors for disease transmission. To test our hypothesis, we exposed surfaces composed of various common environmental materials (i...
January 12, 2018: Journal of Biological Chemistry
Ignazio Cali, Mark L Cohen, Stéphane Haїk, Piero Parchi, Giorgio Giaccone, Steven J Collins, Diane Kofskey, Han Wang, Catriona A McLean, Jean-Philippe Brandel, Nicolas Privat, Véronique Sazdovitch, Charles Duyckaerts, Tetsuyuki Kitamoto, Ermias D Belay, Ryan A Maddox, Fabrizio Tagliavini, Maurizio Pocchiari, Ellen Leschek, Brian S Appleby, Jiri G Safar, Lawrence B Schonberger, Pierluigi Gambetti
The presence of pathology related to the deposition of amyloid-β (Aβ) has been recently reported in iatrogenic Creutzfeldt-Jakob disease (iCJD) acquired from inoculation of growth hormone (GH) extracted from human cadaveric pituitary gland or use of cadaveric dura mater (DM) grafts.To investigate this phenomenon further, a cohort of 27 iCJD cases - 21 with adequate number of histopathological sections - originating from Australia, France, Italy, and the Unites States, were examined by immunohistochemistry, amyloid staining, and Western blot analysis of the scrapie prion protein (PrPSc), and compared with age-group matched cases of sporadic CJD (sCJD), Alzheimer disease (AD) or free of neurodegenerative diseases (non-ND)...
January 8, 2018: Acta Neuropathologica Communications
Daniel Samorodnitsky, Eric M Nicholson
Misfolding of the normally folded prion protein of mammals (PrPC) into infectious fibrils causes a variety of diseases, from scrapie in sheep to chronic wasting disease (CWD) in cervids. The misfolded form of PrPC, termed PrPSc, or in this case PrPCWD, interacts with PrPC to create more PrPCWD. This process is not clearly defined but is affected by the presence and interactions of biotic and abiotic cofactors. These include nucleic acids, lipids, glycosylation, pH, and ionic character. PrPC has been shown to act as a copper-binding protein in vivo, though it also binds to other divalents as well...
January 9, 2018: Prion
Yuan Yao, Xiaoping Dong, Hongzhi Guan, Qiang Lu
RATIONALE: Sporadic Creutzfeldt-Jakob disease (sCJD) mainly occurs in the elderly, with the peak age of onset ranging from 55 to 75 years. The symptoms of sCJD are not unique, and laboratory tests such as magnetic resonance imaging (MRI), electroencephalogram (EEG) and cerebrospinal fluid (CSF)14-3-3 protein have low sensitivity or specificity. Therefore, excluding treatable diseases and establishing a diagnosis could be difficult in young patients with suspected sCJD. Recently, real-time quaking-induced conversion (RT-QuIC) has been used in the diagnosis of sCJD, with more than 95% sensitivity and 100% specificity...
December 2017: Medicine (Baltimore)
Christopher J Silva, Melissa L Erickson-Beltran, Inmaculada Martin-Burriel, Juan José Badiola, Jesus Rodriguez Requena, Rosa Bolea
Atypical scrapie is a sheep prion (PrPSc) disease whose epidemiology is consistent with a sporadic origin and is associated with specific polymorphisms of the normal cellular prion protein (PrPC). To determine the relative amounts of PrP polymorphisms present in scrapie, total PrP was digested with chymotrypsin to generate characteristic peptides spanning relevant polymorphisms at positions 136, 141, 154, 171 and 172 of sheep PrPC. A multiple reaction monitoring method (MRM), employing 15N-labeled internal standards, was used to detect and quantify these polymorphisms present in both the PrPSc and PrPC from heterozygous (ALRRY and ALHQY or ALRQD or AFRQY) atypical scrapie-infected or uninfected control sheep...
December 14, 2017: Analytical Chemistry
Sabina Eigenbrod, Petra Frick, Uwe Bertsch, Gerda Mitteregger-Kretzschmar, Janina Mielke, Marko Maringer, Niklas Piening, Alexander Hepp, Nathalie Daude, Otto Windl, Johannes Levin, Armin Giese, Vignesh Sakthivelu, Jörg Tatzelt, Hans Kretzschmar, David Westaway
Prion diseases have been linked to impaired copper homeostasis and copper induced-oxidative damage to the brain. Divalent metal ions, such as Cu2+ and Zn2+, bind to cellular prion protein (PrPC) at octapeptide repeat (OR) and non-OR sites within the N-terminal half of the protein but information on the impact of such binding on conversion to the misfolded isoform often derives from studies using either OR and non-OR peptides or bacterially-expressed recombinant PrP. Here we created new transgenic mouse lines expressing PrP with disrupted copper binding sites within all four histidine-containing OR's (sites 1-4, H60G, H68G, H76G, H84G, "TetraH>G" allele) or at site 5 (composed of residues His-95 and His-110; "H95G" allele) and monitored the formation of misfolded PrP in vivo...
2017: PloS One
Sarah J Kane, Eric Swanson, Elizabeth O Gordon, Savannah Rocha, Heather R Bender, Luke R Donius, Adriano Aguzzi, Jonathan P Hannan, Mark D Zabel
Complement receptors 1 and 2 (CR1/2 or CD35/CD21) recognize complement-opsonized antigens to initiate innate and adaptive immunity, respectively. CD35 stimulates phagocytosis on macrophages and antigen presentation on follicular dendritic cells (FDCs). CD21 helps activate B cells as part of the B cell coreceptor with CD19 and CD81. Differential splicing of transcripts from the mouse Cr2 gene generates isoforms with both shared and unique complement binding capacities and cell-type expression. In mouse models, genetic depletion of Cr2 causes either a delay or complete prevention of prion disease, but the relative importance of CD35 versus CD21 in promoting prion disease remains unknown...
November 2017: MSphere
Gabriele Giachin, Ridvan Nepravishta, Walter Mandaliti, Sonia Melino, Alja Margon, Denis Scaini, Pierluigi Mazzei, Alessandro Piccolo, Giuseppe Legname, Maurizio Paci, Liviana Leita
Humic substances (HS) are the largest constituent of soil organic matter and are considered as a key component of the terrestrial ecosystem. HS may facilitate the transport of organic and inorganic molecules, as well as the sorption interactions with environmentally relevant proteins such as prions. Prions enter the environment through shedding from live hosts, facilitating a sustained incidence of animal prion diseases such as Chronic Wasting Disease and scrapie in cervid and ovine populations, respectively...
2017: PloS One
T Peter Lopez, Kurt Giles, Brittany N Dugger, Abby Oehler, Carlo Condello, Zuzana Krejciova, Julian A Castaneda, George A Carlson, Stanley B Prusiner
The larger brain of the rat enables a much greater repertoire of complex behaviors than mice, likely making rats preferential for investigating neurodegeneration. Because molecular tools for specific expression of transgenes in the rat brain are sparse, we chose Prnp encoding the prion protein (PrP) to develop a novel vector to drive transgene expression in the rat brain. We compared the rat Prnp sequence with mouse and Syrian hamster Prnp sequences, identifying conserved genetic elements and hypothesizing that these elements would be able to drive neuronal transgene expression...
November 21, 2017: Acta Neuropathologica Communications
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