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Detection of PrPres in Genetically Susceptible Fetuses from Sheep with Natural Scrapie.Scrapie is a transmissible spongiform encephalopathy with a wide PrPres dissemination in many non-neural tissues and with high levels of transmissibility within susceptible populations. Mechanisms of transmission are incompletely understood. It is generally assumed that it is horizontally transmitted by direct contact between animals or indirectly through the environment, where scrapie can remain infectious for years. In contrast, in utero vertical transmission has never been demonstrated and ha ...201122194786
Sensitive and specific detection of sporadic Creutzfeldt-Jakob disease brain prion protein using real-time quaking induced conversion.Real-time quaking induced conversion (RT-QuIC) is an assay in which disease-associated prion protein initiates a rapid conformational transition in recombinant prion protein resulting in the formation of amyloid that can be monitored in real time using the dye thioflavin T. It therefore has potential advantages over analogous cell-free prion protein conversion assays such as protein misfolding cyclic amplification (PMCA). The QuIC assay and the related amyloid seeding assay have largely been dev ...201122031526
experimental interspecies transmission studies of the transmissible spongiform encephalopathies to cattle: comparison to bovine spongiform encephalopathy in cattle.prion diseases or transmissible spongiform encephalopathies (tses) of animals include scrapie of sheep and goats; transmissible mink encephalopathy (tme); chronic wasting disease (cwd) of deer, elk and moose; and bovine spongiform encephalopathy (bse) of cattle. the emergence of bse and its spread to human beings in the form of variant creutzfeldt-jakob disease (vcjd) resulted in interest in susceptibility of cattle to cwd, tme and scrapie. experimental cross-species transmission of tse agents p ...201121908269
prion disease blood test using immunoprecipitation and improved quaking-induced conversion.abstract a key challenge in managing transmissible spongiform encephalopathies (tses) or prion diseases in medicine, agriculture, and wildlife biology is the development of practical tests for prions that are at or below infectious levels. of particular interest are tests capable of detecting prions in blood components such as plasma, but blood typically has extremely low prion concentrations and contains inhibitors of the most sensitive prion tests. one of the latter tests is quaking-induced co ...201121558432
White-tailed deer are susceptible to the agent of sheep scrapie by intracerebral inoculation.ABSTRACT: Interspecies transmission studies afford the opportunity to better understand the potential host range and origins of prion diseases. The purpose of this experiment was to determine susceptibility of white-tailed deer to the agent of scrapie after intracerebral inoculation and to compare clinical signs and lesions to those reported for chronic wasting disease (CWD). Deer (n = 5) were inoculated with 1 mL of a 10% (wt/vol) brain homogenate derived from a sheep clinically affected with s ...201121988781
an overview of animal prion diseases.prion diseases are transmissible neurodegenerative conditions affecting human and a wide range of animal species. the pathogenesis of prion diseases is associated with the accumulation of aggregates of misfolded conformers of host-encoded cellular prion protein (prpc). animal prion diseases include scrapie of sheep and goats, bovine spongiform encephalopathy (bse) or mad cow disease, transmissible mink encephalopathy, feline spongiform encephalopathy, exotic ungulate spongiform encephalopathy, c ...201122044871
heparin enhances the cell-protein misfolding cyclic amplification efficiency of variant creutzfeldt-jakob disease.highly sensitive in vitro screening tests are required to prevent the iatrogenic spread of variant creutzfeldt-jakob disease (vcjd). protein misfolding cyclic amplification (pmca) is a candidate for such a test, but the sensitivity of this method is insufficient. polyanions were reported to enhance pmca efficiency, but their effects on vcjd are unclear. we developed a cell-pmca of vcjd, wherein cell lysate containing exogenously expressed human prp was used as substrates, to investigate the effe ...201121565253
caprine prion gene polymorphisms are associated with decreased incidence of classical scrapie in goat herds in the united kingdom.abstract: the application of genetic breeding programmes to eradicate transmissible spongiform encephalopathies in goats is an important aim for reasons of animal welfare as well as human food safety and food security. based on the positive impact of prnp genetics on sheep scrapie in europe in the past decade, we have established caprine prnp gene variation in more than 1100 goats from the united kingdom and studied the association of prnp alleles with disease phenotypes in 150 scrapie-positive ...201122040234
atypical scrapie isolates involve a uniform prion species with a complex molecular signature.the pathobiology of atypical scrapie, a prion disease affecting sheep and goats, is still poorly understood. in a previous study, we demonstrated that atypical scrapie affecting small ruminants in switzerland differs in the neuroanatomical distribution of the pathological prion protein (prp(d)). to investigate whether these differences depend on host-related vs. pathogen-related factors, we transmitted atypical scrapie to transgenic mice over-expressing the ovine prion protein (tg338). the clini ...201122096587
microsecond unfolding kinetics of sheep prion protein reveals an intermediate that correlates with susceptibility to classical scrapie.the microsecond folding and unfolding kinetics of ovine prion proteins (ovprp) were measured under various solution conditions. a fragment comprising residues 94-233 of the full-length ovprp was studied for four variants with differing susceptibilities to classical scrapie in sheep. the observed biexponential unfolding kinetics of ovprp provides evidence for an intermediate species. however, in contrast to previous results for human prp, there is no evidence for an intermediate under refolding c ...201121889460
an enzymatic treatment of soil-bound prions effectively inhibits replication.chronic wasting disease (cwd) and scrapie can be transmitted through indirect environmental routes, possibly via soil, and a practical decontamination strategy for prion-contaminated soil is currently unavailable. in the laboratory, an enzymatic treatment under environmentally-relevant conditions (22°c, ph 7.4) can degrade soil-bound prp(sc) below the limits of western blot detection. we developed and used a quantitative serial protein misfolding cyclic amplification (pmca) protocol to character ...201121571886
lack of a-disintegrin-and-metalloproteinase adam10 leads to intracellular accumulation and loss of shedding of the cellular prion protein in vivo.abstract: background: the cellular prion protein (prpc) fulfils several yet not completely understood physiological functions. apart from these functions, it has the ability to misfold into a pathogenic scrapie form (prpsc) leading to fatal transmissible spongiform encephalopathies. proteolytic processing of prpc generates n- and c-terminal fragments which play crucial roles both in the pathophysiology of prion diseases and in transducing physiological functions of prpc. a-disintegrin-and-metall ...201121619641
inhibitors of gastric acid secretion increase the risk of prion infection in mice.gastric juice is a unique combination of hydrochloric acid and the proteolytic enzyme pepsin. its main function is to inactivate ingested microorganisms. prions cause fatal transmissible degenerative encephalopathies in animals and man. these diseases have attracted attention due to the proposed link between bovine spongiform encephalopathy in cattle and the occurrence of a new variant creutzfeldt-jakob disease in humans where the most probable route of transmission is via contaminated food. the ...201121936725
heart rate variability analysis in sheep affected by transmissible spongiform encephalopathies.abstract:201122168827
mechanism of prp-amyloid formation in mice without transmissible spongiform encephalopathy.gerstmann-sträussler-scheinker (gss) p102l disease is a familial form of a transmissible spongiform encephalopathy (tse) that can present with or without vacuolation of neuropil. inefficient disease transmission into 101ll transgenic mice was previously observed from gss p102l without vacuolation. however several aged, healthy mice had large plaques composed of abnormal prion protein (prp(d) ). here we perform the ultrastructural characterisation of such plaques and compare them with prp(d ) agg ...201121645162
photodegradation illuminates the role of polyanions in prion infectivity.understanding the mechanism by which prion infectivity is encoded by the misfolded protein prp (sc ) remains a high priority within the prion field. work from several groups has indicated cellular cofactors may be necessary to form infectious prions in vitro. the identity of endogenous prion conversion cofactors is currently unknown, but may include polyanions and/or lipid molecules. in a recent study, we manufactured infectious hamster prions containing purified prp (sc) , co-purified lipid, an ...201121646861
prpsc detection in formalin-fixed paraffin-embedded tissue by elisa.abstract:201122018205
classical scrapie prions in ovine blood are associated with b lymphocytes and platelet-rich plasma.classical scrapie is a naturally occurring transmissible spongiform encephalopathy of sheep and goats characterized by cellular accumulation of abnormal isoforms of prion protein (prpsc) in the central nervous system and the follicles of peripheral lymphoid tissues. previous studies have shown that the whole blood and buffy coat blood fraction of scrapie infected sheep harbor prion infectivity. although prpsc has been detected in peripheral blood mononuclear cells (pbmcs), plasma, and more recen ...201122112371
immunophenotype of cells within cervine rectoanal mucosa-associated lymphoid tissue and mesenteric lymph nodes.rectoanal mucosa-associated lymphoid tissue (ramalt) is a part of the lymphoid system that can be sampled easily in live animals, especially ruminants. ramalt biopsy is useful for the diagnosis of transmissible spongiform encephalopathies, including scrapie in sheep and goats and chronic wasting disease (cwd) in cervids. diagnosis is reliant on detection of abnormal prion protein (prp(d)), which is associated with lymphoid follicles. for enzyme linked immunosorbent assays (elisas) detecting prp( ...201122000034
a study on the analytical sensitivity of 6 bse tests used by the canadian bse reference laboratory.bovine spongiform encephalopathy (bse) surveillance programs have been employed in numerous countries to monitor bse prevalence and to protect animal and human health. since 1999, the european commission (ec) authorized the evaluation and approval of 20 molecular based tests for the rapid detection of the pathological prion protein (prp(sc)) in bse infection. the diagnostic sensitivity, convenience, and speed of these tests have made molecular diagnostics the preferred method for bse surveillanc ...201121412419
characterization of the prnp gene locus in chios dairy sheep and its association with milk production and reproduction traits.the objective of this study was to examine the prion protein gene locus (prnp) in chios sheep. prnp is linked with scrapie resistance in small ruminants. here, its impact on milk production (test-day and total lactation yield) and reproduction (age at first lambing, conception rate at first service, and prolificacy) was assessed. genotyping at codons 136, 154 and 171 (classical scrapie) and 141 (atypical scrapie) was performed using dna from milk somatic cells and pcr-rflp analysis. a total of 1 ...201121749423
hybrid lipoic acid derivatives to attack prion disease on multiple fronts. 201121412985
diphenyl-pyrazole derived compounds increase survival time of mice after prion infection.transmissible spongiform encephalopathies (tses) represent a group of fatal neurodegenerative disorders which can be transmitted by natural infection or inoculation. tses include scrapie in sheep, bse in cattle, and creutzfeldt-jakob disease (cjd) in humans. the emergence of a variant form of cjd (vcjd) which has been associated to bse, produced strong pressure to search for effective treatments with new drugs. up to now, however, tses are incurable, although many efforts have been made in vitro ...201121746938
enhancement of immunohistochemical staining of scrapie proteins and immune cells within lymph nodes of early scrapie-infected sheep.transmissible spongiform encephalopathies (tse) are a group of fatal neurodegenerative diseases that affect animals as well as humans. the oldest of these diseases is scrapie seen in sheep. scrapie is caused by an altered form (prp(sc)), capable of inducing "self-replication" of the normal host prion protein(prp(c)). there is currently no universal standard for antigen retrieval when using immunohistochemistry to simultaneously stain the prp(c) protein and other cellular markers. the use of form ...201121722647
survival of infectious prions in water.the objective of this study was to evaluate the fate of infectious prions in water. known concentrations of infectious prions were added to deionized water, tap water, and wastewater. samples were incubated at 25-¦c, 37-¦c, and 50-¦c for 1 to 8 weeks. the standard scrapie cell assay (ssca) which includes the elispot (enzyme linked immuno-spot) reaction was performed to determine prion infectivity and quantity as a function of time. a reduction of infectious prions was observed at 25-¦c, 37-¦c, a ...201121707419
conserved properties of human and bovine prion strains on transmission to guinea pigs.the first transmissions of human prion diseases to rodents used guinea pigs (gps, cavia porcellus). later, transgenic mice expressing human or chimeric human/mouse prp replaced gps, but the small size of the mouse limits some investigations. to investigate the fidelity of strain-specific prion transmission to gps, we inoculated 'type 1' and 'type 2' prion strains into gps, and we measured the incubation times and determined the strain-specified size of the unglycosylated, protease-resistant (r) ...201121727894
synthesis, structural characterization, formation constants and in vitro cytotoxicity of phenanthroline and imidazolidine-2-thione copper(ii) complexes.the synthesis, crystal structures, physicochemical properties and complex formation constants of [cu(phen)(2)(l)](clo(4))(2) complexes, where phen is 1,10-ortho-phenanthroline and l is a series of substituted imidazolidine-2-thione, have been studied. single crystal x-ray diffraction revealed a distorted trigonal-bipyramidal geometry for all the molecules. the complex formation constants were determined in nonaqueous media by spectrophotometric measurements. testing copper(ii) complexes in mouse ...201121421120
analysis of nucleic acid chaperoning by the prion protein and its inhibition by oligonucleotides.prion diseases are unique neurodegenerative illnesses associated with the conversion of the cellular prion protein (prp(c)) into the aggregated misfolded scrapie isoform, named prp(sc). recent studies on the physiological role of prp(c) revealed that this protein has probably multiple functions, notably in cell-cell adhesion and signal transduction, and in assisting nucleic acid folding. in fact, in vitro findings indicated that the human prp (huprp) possesses nucleic acid binding and annealing ...201121737432
transcriptional profiling of peripheral lymphoid tissue reveals genes and networks linked to ssbp/1 scrapie pathology in sheep.transmissible spongiform encephalopathies (tses) are slow and progressive neurodegenerative diseases of humans and animals. the major target organ for all tses is the brain but some tse agents are associated with prior accumulation within the peripheral lymphoid system. many studies have examined the effects of scrapie infection on the expression of central nervous system (cns) genes, but this study examines the progression of scrapie pathology in the peripheral lymphoid system and how scrapie i ...201121684093
prion disease detection, pmca kinetics, and igg in urine from sheep naturally/experimentally infected with scrapie and deer with preclinical/clinical chronic wasting disease.prion diseases, also known as transmissible spongiform encephalopathies, are fatal neurodegenerative disorders. low levels of infectious agent and limited, infrequent success of disease transmissibility and prp(sc) detection have been reported with urine from experimentally infected clinical cervids and rodents. we report the detection of prion disease-associated seeding activity (pasa) in urine from naturally and orally infected sheep with clinical scrapie agent and orally infected preclinical ...201121715495
replication efficiency of soil-bound prions varies with soil type.prion sorption to soil is thought to play an important role in the transmission of scrapie and chronic wasting disease (cwd) via the environment. sorption of prp to soil and soil minerals is influenced by the strain and species of prp(sc) and by soil characteristics. however, the ability of soil-bound prions to convert prp(c) to prp(sc) under these wide-ranging conditions remains poorly understood. we developed a semiquantitative protein misfolding cyclic amplification (pmca) protocol to evaluat ...201121430062
assessment of the genetic susceptibility of sheep to scrapie by protein misfolding cyclic amplification and comparison with experimental scrapie transmission studies.the susceptibility of sheep to scrapie is influenced mainly by the prion protein polymorphisms a136v, r154h, and q171r/h. here we analyzed the ability of protein misfolding cyclic amplification (pmca) to model the genetic susceptibility of sheep to scrapie. for this purpose, we studied the efficiency of brain homogenates from sheep with different prp genotypes to support prp(sc) amplification by pmca using an arq/arq scrapie inoculum. the results were then compared with those obtained in vivo us ...201121680531
blocking of fcr suppresses the intestinal invasion of scrapie agents.prion diseases are a family of neurodegenerative zoonotic foodborne disorders. although prions can be transmitted orally, the mechanism by which prions are incorporated into the intestine remains unclear. our previous studies have shown that an abnormal isoform of prion protein (prp(sc)), which is the main component of prions, was efficiently incorporated into the intestine in suckling mice but not in weaned mice. furthermore, suckling scid mice lacking maternal antibodies showed decreased uptak ...201121437246
the cellular prion protein mediates neurotoxic signalling of ß-sheet-rich conformers independent of prion replication.formation of aberrant protein conformers is a common pathological denominator of different neurodegenerative disorders, such as alzheimer's disease or prion diseases. moreover, increasing evidence indicates that soluble oligomers are associated with early pathological alterations and that oligomeric assemblies of different disease-associated proteins may share common structural features. previous studies revealed that toxic effects of the scrapie prion protein (prp(sc)), a ß-sheet-rich isoform o ...201121441896
deduction of the evaluation limit and termination timing of multi-round protein misfolding cyclic amplification from a titration curve.in this study, the efficacy of disinfectants in reducing the partially protease-resistant isoform of prion protein was evaluated by a multi-round protein misfolding cyclic amplification (pmca) technique. hamster brains infected with scrapie-derived strain 263k were homogenized, treated under inactivating or mock conditions, and subjected to multi-round pmca. four sets of serial 10-fold dilutions of mock-treated samples were analyzed. although considerable variability was observed in the signal p ...201121443616
Molecular cloning and polymorphism analysis of the prion protein gene in Tan sheep of Ningxia, China.The resistance or susceptibility of sheep to scrapie is associated with polymorphisms of the prion protein gene (PRNP), particularly, single nucleotide polymorphisms (SNPs) in amino acid positions 136, 154 and 171. The prion protein (PrP) gene sequence and the deduced amino acid alignment of prion protein in Tan sheep, a local Chinese sheep breed traditionally raised in Ningxia, northwestern China, were determined and variability of the PrP amino acids sequence was analyzed in this study. The Pr ...201121722718
PRNP haplotype and genotype frequencies in Brazilian sheep: Issues for conservation and breeding programs.Polymorphisms of PRNP gene have been strongly correlated to the susceptibility/resistance to scrapie in sheep. Variants at the coding positions 136, 154 and 171 have been the most frequently associated to susceptibility to classical scrapie. The aim of this study was to estimate PRNP haplotype and genotype frequencies in a sample of 1400 sheep from 13 different breeds that are representative of the main production regions in Brazil. A total of four different alleles (ARR, ARQ, AHQ and VRQ) and n ...201121816449
overexpression of shadoo protein in transgenic mice does not impact the pathogenesis of scrapie.shadoo is a glycoprotein expressed in the adult brain that is an interacting protein of prion protein; however, its function remains to be determined. to elucidate its role in prion pathogenesis, we generated transgenic mice overexpressing wild-type (wt) shadoo driven by the murine prp promoter. expression of the murine sprn transgene significantly increased brain shadoo protein levels in all three mouse lines generated. following infection with mouse-adapted scrapie strain 22l, all transgenic m ...201121458534
transmission of prion strains in a transgenic mouse model overexpressing human a53t mutated α-synuclein.there is a growing interest in the potential roles of misfolded protein interactions in neurodegeneration. to investigate this issue, we inoculated 3 prion strains intracerebrally into transgenic (tgm83) mice that overexpress human a53t α-synuclein. in comparison to nontransgenic controls, there was a striking decrease in the incubation periods of scrapie, classic and h-type bovine spongiform encephalopathies(c-bse and h-bse), with conservation of the histopathologic and biochemical features cha ...201121487306
palladium complexes affect the aggregation of human prion protein prp106-126.many neurodegenerative disorders are induced by protein conformational change. prion diseases are characterized by protein conformational conversion from a normal cellular form (prp(c)) to an abnormal scrapie isoform (prp(sc)). prp106-126 is an accepted model for studying the characteristics of prp(sc) because they share many biological and physiochemical properties. to understand how metal complexes affect the property of the prion peptide, the present work investigated interactions between pd ...201121504185
effect of prp genotype and route of inoculation on the ability of discriminatory western blot to distinguish scrapie from sheep bovine spongiform encephalopathy.procedures for discriminating scrapie from bovine spongiform encephalopathy (bse) in sheep are relevant to ascertain whether bse has entered the sheep population. this study was aimed at investigating whether the suitability of an official eu discriminative method is affected by the sheep prp genotype and route of infection.201121994325
effects of a brain-engraftable microglial cell line expressing anti-prion scfv antibodies on survival times of mice infected with scrapie prions.we first verified that a single chain fv fragment against prion protein (anti-prp scfv) was secreted by hek293t cells and prevented prion replication in infected cells. we then stably expressed anti-prp scfv in brain-engraftable murine microglial cells and intracerebrally injected these cells into mice before or after infection with prions. interestingly, the injection before or at an early time point after infection attenuated the infection marginally but significantly prolonged survival times ...201121516351
Paraffin-embedded tissue blot as a sensitive method for discrimination between classical scrapie and experimental bovine spongiform encephalopathy in sheep.The paraffin-embedded tissue (PET) blot was modified for use as a tool to differentiate between classical scrapie and experimental bovine spongiform encephalopathy (BSE) in sheep. Medulla (obex) from 21 cases of classical scrapie and 6 cases of experimental ovine BSE were used to develop the method such that it can be used as a tool to differentiate between BSE and scrapie in the same way that differential immunohistochemistry (IHC) has been used previously. The differential PET blot successfull ...201121908277
BSE: where are we now? 201121965237
probing structural differences between prp(c) and prp(sc) by surface nitration and acetylation: evidence of conformational change in the c-terminus.we used two chemical modifiers, tetranitromethane (tnm) and acetic anhydride (ac(2)o), which specifically target accessible tyrosine and lysine residues, respectively, to modify recombinant syrian hamster prp(90-231) [rshaprp(90-231)] and shaprp 27-30, the proteinase k-resistant core of prp(sc) isolated from brain of scrapie-infected syrian hamsters. our aim was to find locations of conformational change. modified proteins were subjected to in-gel proteolytic digestion with trypsin or chymotryps ...201121526750
effect of glycans and the glycophosphatidylinositol anchor on strain dependent conformations of scrapie prion protein: improved purifications and infrared spectra.mammalian prion diseases involve conversion of normal prion protein, prp(c), to a pathological aggregated state (prp(res)). the three-dimensional structure of prp(res) is not known, but infrared (ir) spectroscopy has indicated high, strain-dependent β-sheet content. prp(res) molecules usually contain a glycophosphatidylinositol (gpi) anchor and large asn-linked glycans, which can also vary with strain. using ir spectroscopy, we tested the conformational effects of these post-translational modifi ...201121539311
Proteinase K-resistant material in ARR/VRQ sheep brain affected with classical scrapie is composed mainly of VRQ prion protein.Classical scrapie is a prion disease in sheep and goats. In sheep, susceptibility to disease is genetically influenced by single amino acid substitutions. Genetic breeding programs aimed at enrichment of arginine-171 (171R) prion protein (PrP), the so-called ARR allele, in the sheep population have been demonstrated to be effective in reducing the occurrence of classical scrapie in the field. Understanding the molecular basis for this reduced prevalence would serve the assessment of ARR adaptati ...201121917981
A suitable duplex PCR for ovine embryo sex and genotype of PrnP gene determination for MOET-based selection programmes.The objective of this study was to test the suitability of a duplex PCR assay for sex and scrapie resistance genotype determination in fresh embryos. Duplex PCR amplified a repetitive and specific fragment of Y chromosome, used for sex diagnosis, and a PrnP fragment. PrnP codons 134 and 156, and codon 171 were genotyped by restriction fragment length polymorphisms and allele-specific PCR, respectively, after re-amplification of PrnP fragment. The specificity of the method was first assessed by t ...201121851426
initial fate of prions upon peripheral infection: half-life, distribution, clearance, and tissue uptake.prion diseases are infectious neurodegenerative disorders associated with the misfolded prion protein (prp(sc)), which appears to be the sole component of the infectious agent (termed prion). to produce disease, prions have to be absorbed into the body and reach sufficient quantities in the brain. very little is known about the biological mechanisms controlling the initial fate of prions. here, we studied the systemic pharmacokinetics and biodistribution of prp(sc) in vivo. after an intravenous ...201121555356
styryl-based and tricyclic compounds as potential anti-prion agents.prion diseases currently have no effective therapy. these illnesses affect both animal and human populations, and are characterized by the conformational change of a normal self protein prp(c) (c for cellular) to a pathological and infectious conformer, prp(sc) (sc for scrapie). we used a well characterized tissue culture model of prion infection, where mouse neuroblastoma cells (n2a) were infected with 22l prp(sc), to screen compounds for anti-prion activity. in a prior study we designed a libr ...201121931860
biochemical and strain properties of cjd prions: complexity versus simplicity.prions, the agents responsible for transmissible spongiform encephalopathies, are infectious proteins consisting primarily of scrapie prion protein (prp(sc) ), a misfolded, beta-sheet enriched and aggregated form of the host-encoded cellular prion protein (prp(c) ). their propagation is based on an autocatalytic prp conversion process. despite the lack of a nucleic acid genome, different prion strains have been isolated from animal diseases. increasing evidence supports the view that strain-spec ...201121790605
propagation of ovine prions from "poor" transmitter scrapie isolates in ovine prp transgenic mice.ovine prion strains have typically been identified by their transmission properties, which include incubation time and lesion profile, in wild type mice. the existence of scrapie isolates that do not propagate in wild type mice, defined here as "poor" transmitters, are problematic for conventional prion strain typing studies as no incubation time or neuropathology can be recorded. this may arise because of the presence of an ovine prion strain within the original inoculum that does not normally ...201122120785
amyloid: little proteins, big clues. 201121760575
The structural stability of wild-type horse prion protein.Prion diseases (e.g. Creutzfeldt-Jakob disease (CJD), variant CJD (vCJD), Gerstmann-Straussler-Scheinker syndrome (GSS), Fatal Familial Insomnia (FFI) and Kuru in humans, scrapie in sheep, bovine spongiform encephalopathy (BSE or 'mad-cow' disease) and chronic wasting disease (CWD) in cattles) are invariably fatal and highly infectious neurodegenerative diseases affecting humans and animals. However, by now there have not been some effective therapeutic approaches or medications to treat all the ...201121875155
Inactivation of template-directed misfolding of infectious prion protein by ozone.Misfolded prions (PrP(Sc)) are well known for their resistance to conventional decontamination processes. The potential risk of contamination of the water environment, as a result of disposal of specified risk materials (SRM), has raised public concerns. Ozone is commonly utilized in the water industry for inactivation of microbial contaminants and was tested in this study for its ability to inactivate prions (263K hamster scrapie = PrP(Sc)). Treatment variables included initial ozone dose (7.6- ...201122138993
transcriptional modulation in a leukocyte-depleted splenic cell population during prion disease.prion replication in the periphery precedes neuroinvasion in many experimental rodent scrapie models, and in natural sheep scrapie and chronic wasting disease (cwd) in cervids. prions propagate in the germinal centers of secondary lymphoid organs and are strongly associated with follicular dendritic cells (fdc) and possibly circulating dendritic cells and macrophages. given the importance of lymphoid organs in prion disease transmission and pathogenesis, gene expression studies may reveal host f ...201122043911
prion protein self-interaction in prion disease therapy approaches.transmissible spongiform encephalopathies (tses) or prion diseases are unique disorders that are not caused by infectious micro-organisms (bacteria or fungi), viruses or parasites, but rather seem to be the result of an infectious protein. tses are comprised of fatal neurodegenerative disorders affecting both human and animals. prion diseases cause sponge-like degeneration of neuronal tissue and include (among others) creutzfeldt-jacob disease in humans, bovine spongiform encephalopathy (bse) in ...201122029882
from high-throughput cell culture screening to mouse model: identification of new inhibitor classes against prion disease.transmissible spongiform encephalopathies (tse) or prion diseases belong to a category of fatal and so far untreatable neurodegenerative conditions. all prion diseases are characterized by both degeneration in the central nervous system (cns) in humans and animals and the deposition and accumulation of proteinase k-resistant prion protein (prp(res) ). until now, no pharmaceutical product has been available to cure these diseases or to alleviate their associated symptoms. here, a cell-culture scr ...201121755599
Mechanisms of prion disease progression: a chemical reaction network approach.Fatal neurodegenerative diseases such as bovine spongiform encephalopathy in cattle, scrapie in sheep and Creutzfeldt-Jakob disease in humans are caused by prions. Prion is a protein encoded by a normal cellular gene. The cellular form of the prion, namely PrP(C), is benign but can be converted into a disease-causing form (named scrapie), PrP(Sc), by a conformational change from -helix to -sheets. Prions replicate by this conformational change; that is, PrP(Sc) interacts with PrP(C) producing a ...201122129030
Methodology Adaptation of a low-cost medium-throughput genotyping system for ovine prion protein gene polymorphims associated with scrapie.Resistance and susceptibility to scrapie in sheep have been associated with SNPs located at codons 136, 154 and 171 of the prion protein (PRNP) gene. Many countries have sheep breeding programs selecting for resistance to scrapie based on the genotyping of these SNPs. We adapted a fast and robust method for genotyping sheep flocks for these polymorphisms, with reduced costs. Ninety-six samples were genotyped using an adapted SNaPshot PRNP assay, and the results were checked by resequencin ...201122194174
there is no safe dose of prions.understanding the circumstances under which exposure to transmissible spongiform encephalopathies (tses) leads to infection is important for managing risks to public health. based upon ideas in toxicology and radiology, it is plausible that exposure to harmful agents, including tses, is completely safe if the dose is low enough. however, the existence of a threshold, below which infection probability is zero has never been demonstrated experimentally. here we explore this question by combining d ...201121858197
differentiating ovine bse from ch1641 scrapie by serial protein misfolding cyclic amplification.whilst ovine bse displays distinct pathological characteristics to ovine ch1641-like scrapie upon passage in rodents, they have very similar molecular phenotypes. as such, the in vitro differentiation of these strains in routine surveillance programmes presents a significant diagnostic challenge. in this study, using serial protein-misfolding cyclic amplification (spmca), ovine bse was readily amplified in vitro in brain substrates from sheep with v(136)r(154)q(171)/v(136)r(154)q(171) or ahq/ahq ...201121987099
steric zipper formed by hydrophobic peptide fragment of syrian hamster prion protein.steric zippers, where the residues of two neighboring ß-sheet layers are tightly interdigitated, have been proposed as fundamental structural units of amyloid fibrils by eisenberg and co-workers. the steric zipper formed by polypeptides containing the palindromic sequence agaaaaga has a distinctive feature that the distance between two interdigitated ß-sheet layers is comparable to the interstrand distance of the individual ß-sheet. this structural motif is of great interest in the study of prio ...201121749158
real-time quaking-induced conversion: a highly sensitive assay for prion detection.we recently developed a new in vitro amplification technology, designated "real-time quaking-induced conversion (rt-quic)", for detection of the abnormal form of prion protein (prpsc) in easily accessible specimens such as cerebrospinal fluid (csf). after assessment of more than 200 csf specimens from japanese and australian patients, we found no instance of a false positive, and more than 80% accuracy for the correct diagnosis of sporadic creutzfeldt-jakob disease (scjd). furthermore, the rt-qu ...201121778820
Bee venom phospholipase A2 prevents prion peptide induced-cell death in neuronal cells.Bee venom phospholipase A2 (bvPLA2) is a prototypic group-áIII enzyme which consists of unique N-terminal and C-terminal domains and a central secretory PLA2 (sPLA2) domain. This sPLA2 domain is highly homologous with human group-áIII sPLA2. Current evidence suggests that group-áIII sPLA2 may affect some neuronal functions, such as neuritogenesis, neurotransmitter release and neuronal survival. The prion diseases are neurodegenerative disorders characterized by the conversion of the normal cellu ...201121701769
Accumulation and aberrant composition of cholesteryl esters in Scrapie-infected N2a cells and C57BL/6 mouse brains.ABSTRACT:201121816038
isolation of prion with bse properties from farmed goat.transmissible spongiform encephalopathies are fatal neurodegenerative diseases that include variant creutzfeldt-jakob disease in humans, scrapie in small ruminants, and bovine spongiform encephalopathy (bse) in cattle. scrapie is not considered a public health risk, but bse has been linked to variant creutzfeldt-jakob disease. small ruminants are susceptible to bse, and in 2005 bse was identified in a farmed goat in france. we confirm another bse case in a goat in which scrapie was originally di ...201122172149
th2-polarised prp-specific transgenic t-cells confer partial protection against murine scrapie.several hurdles must be overcome in order to achieve efficient and safe immunotherapy against conformational neurodegenerative diseases. in prion diseases, the main difficulty is that the prion protein is tolerated as a self protein, which prevents powerful immune responses. passive antibody therapy is effective only during early, asymptomatic disease, well before diagnosis is made. if efficient immunotherapy of prion diseases is to be achieved, it is crucial to understand precisely how immune t ...201121909267
ten years of bse surveillance in italy: neuropathological findings in clinically suspected cases.between 2001 and 2010, 244 clinically suspected cases of bovine spongiform encephalopathy (bse) were reported in italy. this report summarizes the neuropathological findings in cattle displaying clinical signs consistent with a diagnosis of bse. all animal specimens were submitted for confirmatory testing; samples testing negative underwent neuropathological examination to establish the differential diagnosis. immunohistochemistry for scrapie prion protein (prpsc) at the level of frontal cortex ...201122083104
Hypoxia-inducible factor-1 alpha regulates prion protein expression to protect against neuron cell damage.The human prion protein fragment, PrP (106-126), may contain a majority of the pathological features associated with the infectious scrapie isoform of PrP, known as PrP(Sc). Based on our previous findings that hypoxia protects neuronal cells from PrP (106-126)-induced apoptosis and increases cellular prion protein (PrP(C)) expression, we hypothesized that hypoxia-related genes, including hypoxia-inducible factor-1 alpha (HIF-1a), may regulate PrP(C) expression and that these genes may be involve ...201122036844
a naturally occurring c-terminal fragment of the prion protein (prp) delays disease and acts as a dominant-negative inhibitor of prpsc formation.the cellular prion protein (prp(c)) undergoes constitutive proteolytic cleavage between residues 111/112 to yield a soluble n-terminal fragment (n1) and a membrane-anchored c-terminal fragment (c1). the c1 fragment represents the major proteolytic fragment of prp(c) in brain and several cell types. to explore the role of c1 in prion disease, we generated tg(c1) transgenic mice expressing this fragment (prp(δ23-111)) in the presence and absence of endogenous prp. in contrast to several other n-te ...201122025612
prnp genetic variability and molecular typing of natural goat scrapie isolates in a high number of infected flocks.abstract: one hundred and four scrapie positive and 77 negative goats from 34 greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing. for the first time, the protective s146 variant was reported in greece, while the protective k222 variant was detected in negative but also in five scrapie positive goats from heavily infected flocks. by immunoblotting six isolates, including two goat flockmates ca ...201121961834
lower specific infectivity of protease-resistant prion protein generated in cell-free reactions.prions are unconventional infectious agents that cause transmissible spongiform encephalopathy (tse) diseases, or prion diseases. the biochemical nature of the prion infectious agent remains unclear. previously, using a protein misfolding cyclic amplification (pmca) reaction, infectivity and disease-associated protease-resistant prion protein (prpres) were both generated under cell-free conditions, which supported a nonviral hypothesis for the agent. however, these studies lacked comparative qua ...201122065744
infectious prion protein alters manganese transport and neurotoxicity in a cell culture model of prion disease.protein misfolding and aggregation are considered key features of many neurodegenerative diseases, but biochemical mechanisms underlying protein misfolding and the propagation of protein aggregates are not well understood. prion disease is a classical neurodegenerative disorder resulting from the misfolding of endogenously expressed normal cellular prion protein (prp(c)). although the exact function of prp(c) has not been fully elucidated, studies have suggested that it can function as a metal b ...201121871919
sex effects in mouse prion disease incubation time.prion disease incubation time in mice is determined by many factors including prp expression level, prnp alleles, genetic background, prion strain and route of inoculation. sex differences have been described in age of onset for vcjd and in disease duration for both vcjd and sporadic cjd and have also been shown in experimental models. the sex effects reported for mouse incubation times are often contradictory and detail only one strain of mice or prions, resulting in broad generalisations and a ...201122174884
abrogation of complex glycosylation by swainsonine results in strain- and cell-specific inhibition of prion replication.neuroblastoma-derived n2a-pk1 cells, fibroblastic ld9 cells, and cns-derived cad5 cells can be infected efficiently and persistently by various prion strains, as measured by the standard scrapie cell assay. swainsonine, an inhibitor of golgi α-mannosidase ii that causes abnormal n-glycosylation, strongly inhibits infection of pk1 cells by rml, 79a and 22f, less so by 139a, and not at all by 22l prions, and it does not diminish propagation of any of these strains in ld9 or cad5 cells. misglycosyl ...201121930694
upregulation of micro rna-146a (mirna-146a), a marker for inflammatory neurodegeneration, in sporadic creutzfeldt-jakob disease (scjd) and gerstmann-straussler-scheinker (gss) syndrome.a mouse- and human-brain-abundant, nuclear factor (nf)-кb-regulated, micro rna-146a (mirna-146a) is an important modulator of the innate immune response and inflammatory signaling in specific immunological and brain cell types. levels of mirna-146a are induced in human brain cells challenged with at least five different species of single- or double-stranded dna or rna neurotrophic viruses, suggesting a broad role for mirna-146a in the brain's innate immune response and antiviral immunity. upregu ...201122043907
comparison of nanofiltration efficacy in reducing infectivity of centrifuged versus ultracentrifuged 263k scrapie-infected brain homogenates in "spiked" albumin solutions.background: the safety of plasma-derived products is of concern for possible transmission of variant creutzfeldt-jakob disease. the absence of validated screening tests requires the use of procedures to remove or inactivate prions during the manufacture of plasma-derived products to minimize the risk of transmission. these procedures need proper validation studies based on spiking human plasma or intermediate fractions of plasma fractionation with prions in a form as close as possible to that pr ...201122082124
na+/k+-atpase is present in scrapie-associated fibrils, modulates prp misfolding in vitro and links prp function and dysfunction.transmissible spongiform encephalopathies are characterised by widespread deposition of fibrillar and/or plaque-like forms of the prion protein. these aggregated forms are produced by misfolding of the normal prion protein, prp(c), to the disease-associated form, prp(sc), through mechanisms that remain elusive but which require either direct or indirect interaction between prp(c) and prp(sc) isoforms. a wealth of evidence implicates other non-prp molecules as active participants in the misfoldin ...201122073199
role of cyclophilin a from brains of prion-infected mice in stimulation of cytokine release by microglia and astroglia in vitro.prion diseases or transmissible spongiform encephalopathy (tse) diseases are typically characterized by deposition of abnormally folded partially protease-resistant host-derived prion protein (prpres), which is associated with activated glia and increased release of cytokines. this neuroinflammatory response may play a role in tse pathogenesis. we previously reported that brain homogenates from prion-infected mice induced cytokine protein release in primary astroglial and microglial cell culture ...201122179611
removal of prion infectivity by affinity ligand chromatography during octaplaslg(®) manufacturing - results from animal bioassay studies.background  octaplaslg(®) is a 2nd-generation virus inactivated pooled plasma for infusion. prions are removed by the principle of chromatography, utilizing an affinity ligand gel (lg) developed for binding of prion proteins and their infectivity. the goal of this study was to verify, using the gold standard animal bioassay system, whether or not prion infectivity can be removed by the lg affinity step under conditions used in the routine manufacturing process. materials and methods  aliquots o ...201122070802
molecular interaction of tppp with prp antagonized the cytoprp-induced disruption of microtubule structures and cytotoxicity.tubulin polymerization promoting protein/p25 (tppp/p25), known as a microtubule-associated protein (map), is a brain-specific unstructured protein with a physiological function of stabilizing cellular microtubular ultrastructures. whether tppp involves in the normal functions of prp or the pathogenesis of prion disease remains unknown. here, we proposed the data that tppp formed molecular complex with prp. we also investigated its influence on the aggregation of prp and fibrillization of prp106- ...201121857997
mutation directional selection sheds light on prion pathogenesis.as mutations in the prnp gene account for human hereditary prion diseases (prds), it is crucial to elucidating how these mutations affect the central pathogenic conformational transition of normal cellular prion protein (prp(c)) to abnormal scrapie isoform (prp(sc)). many studies proposed that these pathogenic mutations may make prp more susceptible to conformational change through altering its structure stability. by evaluating the most recent observations regarding pathogenic mutations, it was ...201121679685
common structural traits across pathogenic mutants of the human prion protein and their implications for familial prion diseases.human (hu) familial prion diseases are associated with about 40 point mutations of the gene coding for the prion protein (prp). most of the variants associated with these mutations are located in the globular domain of the protein. we performed 50-áns of molecular dynamics for each of these mutants to investigate their structure in aqueous solution. overall, 1.6-á++s of molecular dynamics data is presented. the calculations are based on the amber(parm99) force field, which has been shown to repr ...201121689662
prp gene polymorphisms in cyprus goats and their association with resistance or susceptibility to natural scrapie.in contrast to scrapie in sheep, the genetic basis of susceptibility to scrapie in goats is not well understood. to study the association of prion protein (prp) alleles with susceptibility to scrapie in goats in cyprus, the coding sequence of the caprine prp gene was determined in 717 goats, including 218 scrapie positive animals. several novel polymorphisms were detected, such as a novel octarepeat variant and a stop codon mutation. amino acids at codons 146 and 154 were associated with suscept ...201120093056
demographic characteristics of scrapie-affected holdings identified by active and passive surveillance schemes in great britain: 2002-2005.several surveillance techniques have been used to quantify the prevalence of both classical and atypical scrapie in british sheep, namely the recording of clinical suspects (rc) and the testing of animals slaughtered at abattoir (as) or reported as fallen stock (fs). any estimate of prevalence based on a particular source is likely to have been affected by demographic differences in the populations sampled. in this study, the demographic characteristics of scrapie-affected holdings detected by e ...201120056463
a partially folded state of ovalbumin at low ph tends to aggregate.at ph 2, ovalbumin retains native-like secondary structure as seen by far-uv cd and ftir, but lacks well-defined tertiary structure as seen by the fluorescence and near-uv cd spectra. addition of 20 mm trifluoroacetic acid (tfa) or 30 mm trichloroacetic acid (tca) on acid-induced state results in protein aggregation. this aggregated state possesses extensive β-sheet structure as revealed by far-uv cd and ftir spectroscopy. furthermore, the aggregates exhibit decreased ans fluorescence and increa ...201120703954
molecular typing of protease-resistant prion protein in transmissible spongiform encephalopathies of small ruminants, france, 2002-2009.the agent that causes bovine spongiform encephalopathy (bse) may be infecting small ruminants, which could have serious implications for human health. to distinguish bse from scrapie and to examine the molecular characteristics of the protease-resistant prion protein (prp(res)), we used a specifically designed western blot method to test isolates from 648 sheep and 53 goats. during 2002-2009, classical non-nor98 transmissible spongiform encephalopathy had been confirmed among ≈1.7 million small ...201121192855
cellular and sub-cellular pathology of animal prion diseases: relationship between morphological changes, accumulation of abnormal prion protein and clinical disease.the transmissible spongiform encephalopathies (tses) or prion diseases of animals are characterised by cns spongiform change, gliosis and the accumulation of disease-associated forms of prion protein (prp(d)). particularly in ruminant prion diseases, a wide range of morphological types of prp(d) depositions are found in association with neurons and glia. when light microscopic patterns of prp(d) accumulations are correlated with sub-cellular structure, intracellular prp(d) co-localises with lyso ...201120532540
polymorphism of prion protein gene in sheep of inner mongolian, china.susceptibility to natural scrapie in sheep is associated with polymorphisms at codons 136, 154 and 171 of the prion protein (prp) gene. to assess the risk of scrapie in sheep raised in china, dna from 30 sheep of two breeds was isolated, amplified and sequenced for the prp gene. the ovine prp gene was found to be highly homogenous. the genotype associated with high susceptibility to scrapie (vrq) was absent, whereas that associated with the resistance (arr) was present in 6.7% of sheep examined. ...201121063762
gene expression analysis in distinct regions of the central nervous system during the development of ssbp/1 sheep scrapie.rodent scrapie models have been exploited to define the molecular basis for the progression of neuropathological changes in tse diseases. we aim to assess whether cns gene expression changes consistently observed in mouse models are of generic relevance, for example to natural tse diseases, or are tse strain, host species or brain region specific. six genes, representing distinct physiological pathways and showing consistent changes in expression levels with disease progression in murine scrapie ...201120576367
expression and knockdown of cellular prion protein (prpc) in differentiating mouse embryonic stem cells.the mammalian cellular prion protein (prp(c)) is a highly conserved glycoprotein that may undergo conversion into a conformationally altered isoform (scrapie prion protein or prp(sc)), widely believed to be the pathogenic agent of transmissible spongiform encephalopathies (tses). although much is known about pathogenic prp conversion and its role in tses, the normal function of prp(c) is poorly understood. given the abundant expression of prp(c) in the developing mammalian cns and the spatial as ...201120926176
glypican-1 facilitates prion conversion in lipid rafts.the conformational conversion of the cellular prion protein (prp(c)) to the infectious form (prp(sc)) is the critical step in the pathogenesis of prion diseases such as creutzfeldt-jakob disease in humans and scrapie in sheep. cholesterol-rich lipid rafts play a key role in the conversion of prp(c) to prp(sc) and other cellular components have been identified as important cofactors to trigger, enhance, or accelerate prion formation. amongst these heparan sulphate proteoglycans (hspgs) and their ...201120681952
an assessment of the efficiency of prpsc detection in rectal mucosa and third-eyelid biopsies from animals infected with scrapie.in classical scrapie, detection of prpsc on lymphoreticular system is used for the in vivo and post mortem diagnosis of the disease. however, the sensitivity of this methodology is not well characterised because the magnitude and duration of lymphoid tissue involvement can vary considerably. the aim of the present study was to evaluate the efficiency of detecting prpsc in rectal mucosa and third-eyelid biopsies. a total of 474 genetically susceptible sheep and 24 goats from three scrapie infecte ...201120685048
historical overview of prion diseases: a view from afar.the transmissible spongiform encephalopathies (tses), or prion diseases, are a group of neurodegenerative disorders which include kuru, creutzfeldt-jakob disease (cjd), gerstmann-sträussler-scheinker (gss) syndrome, and fatal familial insomnia in men, natural scrapie in sheep, goats and mufflons, transmissible mink encephalopathy in ranch-reared mink, chronic wasting disease of mule deer and elk, bovine spongiform encephalopathy or "mad cow disease" and its analogues in several exotic species of ...201222505359
time course of prion seeding activity in cerebrospinal fluid of scrapie-infected hamsters after intratongue and intracerebral inoculations.to assess prospects for early diagnosis of prion disease based on prion seeding activity in cerebrospinal fluid (csf), we measured the activity over time in scrapie-infected hamsters by real-time quaking-induced conversion (rt-quic). after intracerebral inoculation, activity appeared in csf within 1 day and plateaued weeks before the onset of clinical signs. however, after intratongue inoculation, activity first appeared in csf with the onset of clinical signs, well after higher-level accumulati ...201222238438
heat shock protein 70 selectively mediates the degradation of cytosolic prps and restores the cytosolic prp-induced cytotoxicity via a molecular interaction.although the aggregation of prpsc is thought to be crucial for the neuropathology of prion diseases, there is evidence in cultured cells and transgenic mice that neuronal death can be triggered by the accumulation of cytosolic prps, leading to the hypothesis that the accumulation of prps in the cytosol of neurons may be a primary neurotoxic culprit. hsp70, a molecular chaperone involved in protein folding/refolding and degradation in the cytoplasm, has a protective effect in some models of neuro ...201223216755
acetone precipitation of the scrapie agent results in successful recovery of prp(sc) but decreased infectivity.bioassay is considered the most sensitive method for evaluating prion inactivation procedures. because prions are resistant to methods effective at inactivating conventional microorganisms, prion inactivation research has focused on relatively harsh alternatives, such as concentrated sodium hypochlorite or sodium hydroxide. often, bioassay for residual infectivity in these studies requires dilution or biochemical alteration of the treated sample in order to maintain subject health and survival. ...201222519670
Frequency distribution of PRNP polymorphisms in the Pakistani population.Prion diseases are neurodegenerative conditions caused by misfolding of a normal host-encoded prion protein (PrP(C)) into pathogenic scrapie prion protein (PrP(Sc)). In human prion diseases, the M129V prion protein polymorphism is known to confer susceptibility to the disease, determines PrP(Sc) conformation and alters clinicopathological phenotypes. To date, all clinicopathologically confirmed cases of a variant form of Cruetzfeldt-Jacob disease (vCJD) have been 129MM homozygotes. There is also ...201222062631
the effects of host age on the transport of complement-bound complexes to the spleen and the pathogenesis of intravenous scrapie infection.infections with variant creutzfeldt-jakob disease (vcjd) have almost exclusively occurred in young patients, but the reasons for this age distribution are uncertain. our data suggest that the pathogenesis of many peripherally acquired transmissible spongiform encephalopathy (tse) agents is less efficient in aged individuals. four vcjd cases linked to transfusion of vcjd-contaminated blood or blood products have been described. three cases occurred in elderly patients, implying that intravenous e ...201222031932
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