scholarly journals Host Determinants of Prion Strain Diversity Independent of Prion Protein Genotype

2015 ◽  
Vol 89 (20) ◽  
pp. 10427-10441 ◽  
Author(s):  
Jenna Crowell ◽  
Andrew Hughson ◽  
Byron Caughey ◽  
Richard A. Bessen
Keyword(s):  
Transgenic Mice ◽  
Prion Protein ◽  
Protein Gene ◽  
Phenotypic Diversity ◽  
Prion Diseases ◽  
Conformational Stability ◽  
Epigenetic Mechanism ◽  
Prion Strain ◽  
Disease Phenotypes ◽  
Prion Strains

ABSTRACTPhenotypic diversity in prion diseases can be specified by prion strains in which biological traits are propagated through an epigenetic mechanism mediated by distinct PrPScconformations. We investigated the role of host-dependent factors on phenotypic diversity of chronic wasting disease (CWD) in different host species that express the same prion protein gene (Prnp). Two CWD strains that have distinct biological, biochemical, and pathological features were identified in transgenic mice that express the Syrian golden hamster (SGH)Prnp. The CKY strain of CWD had a shorter incubation period than the WST strain of CWD, but after transmission to SGH, the incubation period of CKY CWD was ∼150 days longer than WST CWD. Limited proteinase K digestion revealed strain-specific PrPScpolypeptide patterns that were maintained in both hosts, but the solubility and conformational stability of PrPScdiffered for the CWD strains in a host-dependent manner. WST CWD produced PrPScamyloid plaques in the brain of the SGH that were partially insoluble and stable at a high concentration of protein denaturant. However, in transgenic mice, PrPScfrom WST CWD did not assemble into plaques, was highly soluble, and had low conformational stability. Similar studies using the HY and DY strains of transmissible mink encephalopathy resulted in minor differences in prion biological and PrPScproperties between transgenic mice and SGH. These findings indicate that host-specific pathways that are independent ofPrnpcan alter the PrPScconformation of certain prion strains, leading to changes in the biophysical properties of PrPSc, neuropathology, and clinical prion disease.IMPORTANCEPrions are misfolded pathogenic proteins that cause neurodegeneration in humans and animals. Transmissible prion diseases exhibit a spectrum of disease phenotypes and the basis of this diversity is encoded in the structure of the pathogenic prion protein and propagated by an epigenetic mechanism. In the present study, we investigated prion diversity in two hosts species that express the same prion protein gene. While prior reports have demonstrated that prion strain properties are stable upon infection of the same host species and prion protein genotype, our findings indicate that certain prion strains can undergo dramatic changes in biological properties that are not dependent on the prion protein. Therefore, host factors independent of the prion protein can affect prion diversity. Understanding how host pathways can modify prion disease phenotypes may provide clues on how to alter prion formation and lead to treatments for prion, and other, human neurodegenerative diseases of protein misfolding.

scholarly journals Characterization of two distinct prion strains derived from bovine spongiform encephalopathy transmissions to inbred mice

2004 ◽  
Vol 85 (8) ◽  
pp. 2471-2478 ◽  
Author(s):  
Sarah E. Lloyd ◽  
Jacqueline M. Linehan ◽  
Melanie Desbruslais ◽  
Susan Joiner ◽  
Jennifer Buckell ◽  
...  
Keyword(s):  
Bovine Spongiform Encephalopathy ◽  
Prion Protein ◽  
Incubation Time ◽  
Inbred Mice ◽  
Biochemical Properties ◽  
Distinct Pattern ◽  
Spongiform Encephalopathy ◽  
Prion Strain ◽  
Disease Phenotypes ◽  
Prion Strains

Distinct prion strains can be distinguished by differences in incubation period, neuropathology and biochemical properties of disease-associated prion protein (PrPSc) in inoculated mice. Reliable comparisons of mouse prion strain properties can only be achieved after passage in genetically identical mice, as host prion protein sequence and genetic background are known to modulate prion disease phenotypes. While multiple prion strains have been identified in sheep scrapie and Creutzfeldt–Jakob disease, bovine spongiform encephalopathy (BSE) is thought to be caused by a single prion strain. Primary passage of BSE prions to different lines of inbred mice resulted in the propagation of two distinct PrPSc types, suggesting that two prion strains may have been isolated. To investigate this further, these isolates were subpassaged in a single line of inbred mice (SJL) and it was confirmed that two distinct prion strains had been identified. MRC1 was characterized by a short incubation time (110±3 days), a mono-glycosylated-dominant PrPSc type and a generalized diffuse pattern of PrP-immunoreactive deposits, while MRC2 displayed a much longer incubation time (155±1 days), a di-glycosylated-dominant PrPSc type and a distinct pattern of PrP-immunoreactive deposits and neuronal loss. These data indicate a crucial involvement of the host genome in modulating prion strain selection and propagation in mice. It is possible that multiple disease phenotypes may also be possible in BSE prion infection in humans and other animals.

scholarly journals Prion Strain Characterization of a Novel Subtype of Creutzfeldt-Jakob Disease

2017 ◽  
Vol 91 (11) ◽  
Author(s):  
Roberta Galeno ◽  
Michele Angelo Di Bari ◽  
Romolo Nonno ◽  
Franco Cardone ◽  
Marco Sbriccoli ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Prion Protein ◽  
Protein Gene ◽  
Prion Protein Gene ◽  
Prion Strain ◽  
Bank Voles ◽  
Jakob Disease ◽  
Codon 129

ABSTRACT In 2007, we reported a patient with an atypical form of Creutzfeldt-Jakob disease (CJD) heterozygous for methionine-valine (MV) at codon 129 who showed a novel pathological prion protein (PrPTSE) conformation with an atypical glycoform (AG) profile and intraneuronal PrP deposition. In the present study, we further characterize the conformational properties of this pathological prion protein (PrPTSE MVAG), showing that PrPTSE MVAG is composed of multiple conformers with biochemical properties distinct from those of PrPTSE type 1 and type 2 of MV sporadic CJD (sCJD). Experimental transmission of CJD-MVAG to bank voles and gene-targeted transgenic mice carrying the human prion protein gene (TgHu mice) showed unique transmission rates, survival times, neuropathological changes, PrPTSE deposition patterns, and PrPTSE glycotypes that are distinct from those of sCJD-MV1 and sCJD-MV2. These biochemical and experimental data suggest the presence of a novel prion strain in CJD-MVAG. IMPORTANCE Sporadic Creutzfeldt-Jakob disease is caused by the misfolding of the cellular prion protein, which assumes two different major conformations (type 1 and type 2) and, together with the methionine/valine polymorphic codon 129 of the prion protein gene, contribute to the occurrence of distinct clinical-pathological phenotypes. Inoculation in laboratory rodents of brain tissues from the six possible combinations of pathological prion protein types with codon 129 genotypes results in the identification of 3 or 4 strains of prions. We report on the identification of a novel strain of Creutzfeldt-Jakob disease isolated from a patient who carried an abnormally glycosylated pathological prion protein. This novel strain has unique biochemical characteristics, does not transmit to humanized transgenic mice, and shows exclusive transmission properties in bank voles. The identification of a novel human prion strain improves our understanding of the pathogenesis of the disease and of possible mechanisms of prion transmission.

scholarly journals Porcine Prion Protein as a Paradigm of Limited Susceptibility to Prion Strain Propagation

2020 ◽  
Author(s):  
Juan Carlos Espinosa ◽  
Alba Marín-Moreno ◽  
Patricia Aguilar-Calvo ◽  
Sylvie L Benestad ◽  
Olivier Andreoletti ◽  
...  
Keyword(s):  
Prion Protein ◽  
Protein Misfolding ◽  
Prion Diseases ◽  
Conformational Flexibility ◽  
Cellular Prion Protein ◽  
Spongiform Encephalopathy ◽  
Prion Strain ◽  
Experimental Transmission ◽  
Prion Strains ◽  
Jakob Disease

Abstract Although experimental transmission of bovine spongiform encephalopathy (BSE) to pigs and transgenic mice expressing pig cellular prion protein (PrPC) (porcine PrP [PoPrP]–Tg001) has been described, no natural cases of prion diseases in pig were reported. This study analyzed pig-PrPC susceptibility to different prion strains using PoPrP-Tg001 mice either as animal bioassay or as substrate for protein misfolding cyclic amplification (PMCA). A panel of isolates representatives of different prion strains was selected, including classic and atypical/Nor98 scrapie, atypical-BSE, rodent scrapie, human Creutzfeldt-Jakob-disease and classic BSE from different species. Bioassay proved that PoPrP-Tg001-mice were susceptible only to the classic BSE agent, and PMCA results indicate that only classic BSE can convert pig-PrPC into scrapie-type PrP (PrPSc), independently of the species origin. Therefore, conformational flexibility constraints associated with pig-PrP would limit the number of permissible PrPSc conformations compatible with pig-PrPC, thus suggesting that pig-PrPC may constitute a paradigm of low conformational flexibility that could confer high resistance to the diversity of prion strains.

scholarly journals Dimerization of the cellular prion protein inhibits propagation of scrapie prions

2018 ◽  
Vol 293 (21) ◽  
pp. 8020-8031 ◽  
Author(s):  
Anna D. Engelke ◽  
Anika Gonsberg ◽  
Simrika Thapa ◽  
Sebastian Jung ◽  
Sarah Ulbrich ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Prion Protein ◽  
Conformational Transition ◽  
Prion Diseases ◽  
Neuroblastoma Cells ◽  
Direct Interaction ◽  
Cellular Prion Protein ◽  
Dominant Negative ◽  
Dimerization Domain ◽  
Hydrophobic Domain

A central step in the pathogenesis of prion diseases is the conformational transition of the cellular prion protein (PrPC) into the scrapie isoform, denoted PrPSc. Studies in transgenic mice have indicated that this conversion requires a direct interaction between PrPC and PrPSc; however, insights into the underlying mechanisms are still missing. Interestingly, only a subfraction of PrPC is converted in scrapie-infected cells, suggesting that not all PrPC species are suitable substrates for the conversion. On the basis of the observation that PrPC can form homodimers under physiological conditions with the internal hydrophobic domain (HD) serving as a putative dimerization domain, we wondered whether PrP dimerization is involved in the formation of neurotoxic and/or infectious PrP conformers. Here, we analyzed the possible impact on dimerization of pathogenic mutations in the HD that induce a spontaneous neurodegenerative disease in transgenic mice. Similarly to wildtype (WT) PrPC, the neurotoxic variant PrP(AV3) formed homodimers as well as heterodimers with WTPrPC. Notably, forced PrP dimerization via an intermolecular disulfide bond did not interfere with its maturation and intracellular trafficking. Covalently linked PrP dimers were complex glycosylated, GPI-anchored, and sorted to the outer leaflet of the plasma membrane. However, forced PrPC dimerization completely blocked its conversion into PrPSc in chronically scrapie-infected mouse neuroblastoma cells. Moreover, PrPC dimers had a dominant-negative inhibition effect on the conversion of monomeric PrPC. Our findings suggest that PrPC monomers are the major substrates for PrPSc propagation and that it may be possible to halt prion formation by stabilizing PrPC dimers.

scholarly journals Identification of Prion Disease-Related Somatic Mutations in the Prion Protein Gene (PRNP) in Cancer Patients

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1480 ◽  
Author(s):  
Yong-Chan Kim ◽  
Sae-Young Won ◽  
Byung-Hoon Jeong
Keyword(s):  
Cancer Patient ◽  
Cancer Patients ◽  
Prion Protein ◽  
Patient Population ◽  
Somatic Mutations ◽  
Protein Gene ◽  
Prion Diseases ◽  
Prnp Gene ◽  
Prion Protein Gene ◽  
Total Cancer

Prion diseases are caused by misfolded prion protein (PrPSc) and are accompanied by spongiform vacuolation of brain lesions. Approximately three centuries have passed since prion diseases were first discovered around the world; however, the exact role of certain factors affecting the causative agent of prion diseases is still debatable. In recent studies, somatic mutations were assumed to be cause of several diseases. Thus, we postulated that genetically unstable cancer tissue may cause somatic mutations in the prion protein gene (PRNP), which could trigger the onset of prion diseases. To identify somatic mutations in the PRNP gene in cancer tissues, we analyzed somatic mutations in the PRNP gene in cancer patients using the Cancer Genome Atlas (TCGA) database. In addition, to evaluate whether the somatic mutations in the PRNP gene in cancer patients had a damaging effect, we performed in silico analysis using PolyPhen-2, PANTHER, PROVEAN, and AMYCO. We identified a total of 48 somatic mutations in the PRNP gene, including 8 somatic mutations that are known pathogenic mutations of prion diseases. We identified significantly different distributions among the types of cancer, the mutation counts, and the ages of diagnosis between the total cancer patient population and cancer patients carrying somatic mutations in the PRNP gene. Strikingly, although invasive breast carcinoma and glioblastoma accounted for a high percentage of the total cancer patient population (9.9% and 5.4%, respectively), somatic mutations in the PRNP gene have not been identified in these two cancer types. We suggested the possibility that somatic mutations of the PRNP gene in glioblastoma can be masked by a diagnosis of prion disease. In addition, we found four aggregation-prone somatic mutations, these being L125F, E146Q, R151C, and K204N. To the best of our knowledge, this is the first specific analysis of the somatic mutations in the PRNP gene in cancer patients.

scholarly journals Prion Protein Expression Differences in Microglia and Astroglia Influence Scrapie-Induced Neurodegeneration in the Retina and Brain of Transgenic Mice

2007 ◽  
Vol 81 (19) ◽  
pp. 10340-10351 ◽  
Author(s):  
Lisa Kercher ◽  
Cynthia Favara ◽  
James F. Striebel ◽  
Rachel LaCasse ◽  
Bruce Chesebro
Keyword(s):  
Transgenic Mice ◽  
Prion Protein ◽  
Microglial Activation ◽  
Prion Diseases ◽  
Cell Types ◽  
Mouse Strains ◽  
Activation Markers ◽  
Activated Microglia ◽  
Morphological Criteria ◽  
Scrapie Infection

ABSTRACT Activated microglia and astroglia are known to be involved in a variety of neurodegenerative diseases, including prion diseases. In the present experiments, we studied activation of astroglia and microglia after intraocular scrapie infection in transgenic mice expressing prion protein (PrP) in multiple cell types (tg7 mice) or in neurons only (tgNSE mice). In this model, scrapie infection and protease-resistant PrP deposition occurs in the retinas of both strains of mice, but retinal degeneration is observed only in tg7 mice. Our results showed that the retinas of tg7 and tgNSE mice both had astroglial activation with increased chemokine expression during the course of infection. However, only tg7 retinas exhibited strong microglial activation compared to tgNSE retinas, which showed little microglial activation by biochemical or morphological criteria. Therefore, microglial PrP expression might be required for scrapie-induced retinal microglial activation and damage. Furthermore, microglial activation preceded retinal neurodegeneration in tg7 mice, suggesting that activated microglia might contribute to the degenerative process, rather than being a response to the damage. Surprisingly, brain differed from retina in that an altered profile of microglial activation markers was upregulated, and the profiles in the two mouse strains were indistinguishable. Microglial activation in the brain was associated with severe brain vacuolation and neurodegeneration, leading to death. Thus, retinal and brain microglia appeared to differ in their requirements for activation, suggesting that different activation pathways occur in the two tissues.

scholarly journals No polymorphisms in the coding region of the prion-like protein gene in Thoroughbred racehorses

2019 ◽  
Vol 67 (2) ◽  
pp. 174-182 ◽  
Author(s):  
Min-Ju Jeong ◽  
Byung-Hoon Jeong
Keyword(s):  
Amino Acid ◽  
Prion Protein ◽  
Protein Gene ◽  
Prion Diseases ◽  
Amino Acid Sequences ◽  
Prion Protein Gene ◽  
Coding Region ◽  
Thoroughbred Racehorses ◽  
Thoroughbred Horses ◽  
Protein Isoform

Prion diseases are fatal neurodegenerative diseases characterised by the accumulation of an abnormal prion protein isoform (PrPSc), which is converted from the normal prion protein (PrPC). Prion diseases have been reported in an extensive number of species but not in horses up to now; therefore, horses are known to be a species resistant to prion diseases. The prion-like protein gene (PRND) is closely located downstream of the prion protein gene (PRNP) and the prion-like protein (Doppel) is a homologue with PrP. Previous studies have shown that an association between prion diseases and polymorphisms of the PRND gene is reported in the main hosts of prion diseases. Hence, we examined the genetic variations of the PRND gene in Thoroughbred horses. Interestingly, polymorphisms of the PRND gene were not detected. In addition, we conducted a comparative analysis of the amino acid sequences of the PRND gene to identify the differences between horses and other species. The amino acid sequence of the horse PRND gene showed the highest identity to that of sheep (83.7%), followed by that of goats, cattle and humans. To the best of our knowledge, this is the first genetic study of the PRND gene in horses.

scholarly journals Increased Infectivity of Anchorless Mouse Scrapie Prions in Transgenic Mice Overexpressing Human Prion Protein

2015 ◽  
Vol 89 (11) ◽  
pp. 6022-6032 ◽  
Author(s):  
Brent Race ◽  
Katie Phillips ◽  
Kimberly Meade-White ◽  
James Striebel ◽  
Bruce Chesebro
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Transgenic Mice ◽  
Prion Protein ◽  
Prion Diseases ◽  
Human Species ◽  
Species Barrier ◽  
Gpi Anchor ◽  
Prion Infection ◽  
Barrier Model

ABSTRACTPrion protein (PrP) is found in all mammals, mostly as a glycoprotein anchored to the plasma membrane by a C-terminal glycosylphosphatidylinositol (GPI) linkage. Following prion infection, host protease-sensitive prion protein (PrPsen or PrPC) is converted into an abnormal, disease-associated, protease-resistant form (PrPres). Biochemical characteristics, such as the PrP amino acid sequence, and posttranslational modifications, such as glycosylation and GPI anchoring, can affect the transmissibility of prions as well as the biochemical properties of the PrPres generated. Previousin vivostudies on the effects of GPI anchoring on prion infectivity have not examined cross-species transmission. In this study, we tested the effect of lack of GPI anchoring on a species barrier model using mice expressing human PrP. In this model, anchorless 22L prions derived from tg44 mice were more infectious than 22L prions derived from C57BL/10 mice when tested in tg66 transgenic mice, which expressed wild-type anchored human PrP at 8- to 16-fold above normal. Thus, the lack of the GPI anchor on the PrPres from tg44 mice appeared to reduce the effect of the mouse-human PrP species barrier. In contrast, neither source of prions induced disease in tgRM transgenic mice, which expressed human PrP at 2- to 4-fold above normal.IMPORTANCEPrion protein (PrP) is found in all mammals, usually attached to cells by an anchor molecule called GPI. Following prion infection, PrP is converted into a disease-associated form (PrPres). While most prion diseases are species specific, this finding is not consistent, and species barriers differ in strength. The amino acid sequence of PrP varies among species, and this variability affects prion species barriers. However, other PrP modifications, including glycosylation and GPI anchoring, may also influence cross-species infectivity. We studied the effect of PrP GPI anchoring using a mouse-to-human species barrier model. Experiments showed that prions produced by mice expressing only anchorless PrP were more infectious than prions produced in mice expressing anchored PrP. Thus, the lack of the GPI anchor on prions reduced the effect of the mouse-human species barrier. Our results suggest that prion diseases that produce higher levels of anchorless PrP may pose an increased risk for cross-species infection.

scholarly journals Neuroinvasion in Prion Diseases: The Roles of Ascending Neural Infection and Blood Dissemination

2010 ◽  
Vol 2010 ◽  
pp. 1-16 ◽  
Author(s):  
Sílvia Sisó ◽  
Lorenzo González ◽  
Martin Jeffrey
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Prion Protein ◽  
Prion Diseases ◽  
Autonomic Nerves ◽  
Peripheral Organs ◽  
Prion Strains ◽  
New Variant ◽  
Jakob Disease ◽  
The Central Nervous System

Prion disorders are infectious, neurodegenerative diseases that affect humans and animals. Susceptibility to some prion diseases such as kuru or the new variant of Creutzfeldt-Jakob disease in humans and scrapie in sheep and goats is influenced by polymorphisms of the coding region of the prion protein gene, while other prion disorders such as fatal familial insomnia, familial Creutzfeldt-Jakob disease, or Gerstmann-Straussler-Scheinker disease in humans have an underlying inherited genetic basis. Several prion strains have been demonstrated experimentally in rodents and sheep. The progression and pathogenesis of disease is influenced by both genetic differences in the prion protein and prion strain. Some prion diseases only affect the central nervous system whereas others involve the peripheral organs prior to neuroinvasion. Many experiments undertaken in different species and using different prion strains have postulated common pathways of neuroinvasion. It is suggested that prions access the autonomic nerves innervating peripheral organs and tissues to finally reach the central nervous system. We review here published data supporting this view and additional data suggesting that neuroinvasion may concurrently or independently involve the blood vascular system.

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