scholarly journals Caprine PRNP polymorphisms N146S and Q222K are associated with proteolytic cleavage of PrPC

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Sally A. Madsen-Bouterse ◽  
Paula Stewart ◽  
Helen Williamson ◽  
David A. Schneider ◽  
Wilfred Goldmann
Keyword(s):  
Disease Resistance ◽  
Amino Acid ◽  
Genetic Control ◽  
Brain Tissue ◽  
Relative Abundance ◽  
Small Ruminant ◽  
Prion Diseases ◽  
Cellular Prion Protein ◽  
Wild Type ◽  
Tissue Homogenates

AbstractExpression of the cellular prion protein (PrPC) is crucial for the development of prion diseases. Amino acid changes in PrPC or a reduced amount of PrPC may modulate disease resistance. The relative abundance of C1, a natural α-cleavage fragment of PrPC, was previously found to be associated with a resistant PRNP genotype in sheep. Goats are another small ruminant where classical scrapie susceptibility is under strong genetic control. In this study, we assessed PrPC in goats for the existence of similar associations between PrPC fragments and genotype. Brain tissue homogenates from scrapie-free goats with wild type PRNP or polymorphisms (I142M, H143R, N146S, or Q222K) were deglycosylated prior to immunoblot for assessment of the relative abundance of the C1 fragment of PrPC. The presence of K222 or S146 alleles demonstrated significantly different relative levels of C1 compared to that observed in wild type goats, which suggests that the genotype association with C1 is neither unique to sheep nor exclusive to the ovine Q171R dimorphism.

scholarly journals TSE Diagnostics: Recent Advances in Immunoassaying Prions

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Anja Lukan ◽  
Tanja Vranac ◽  
Vladka Čurin Šerbec
Keyword(s):  
Cerebrospinal Fluid ◽  
Neurodegenerative Diseases ◽  
Brain Tissue ◽  
Prion Diseases ◽  
Cellular Prion Protein ◽  
Transmissible Spongiform Encephalopathies ◽  
Post Mortem ◽  
Definite Diagnosis ◽  
Spongiform Encephalopathies ◽  
Recent Advances

Transmissible spongiform encephalopathies (TSEs) or prion diseases are a group of rare fatal neurodegenerative diseases, affecting humans and animals. They are believed to be the consequence of the conversion of the cellular prion protein to its aggregation-prone,β-sheet-rich isoform, named prion. Definite diagnosis of TSEs is determinedpost mortem. For this purpose, immunoassays for analyzing brain tissue have been developed. However, the ultimate goal of TSE diagnostics is anante mortemtest, which would be sensitive enough to detect prions in body fluids, that is, in blood, cerebrospinal fluid, or urine. Such a test would be of paramount importance also for screening of asymptomatic carriers of the disease with the aim of increasing food, drugs, and blood-derived products safety. In the present paper, we have reviewed recent advances in the development of immunoassays for the detection of prions.

scholarly journals Untangling the Prion-Like Misfolding Mechanism for Neurodegenerative Diseases

2018 ◽  
Author(s):  
Daniela Sarnataro
Keyword(s):  
Quality Control ◽  
Neurodegenerative Disorders ◽  
Lipid Membrane ◽  
Prion Diseases ◽  
Phosphatidyl Inositol ◽  
Cellular Prion Protein ◽  
Wild Type ◽  
Er Quality Control ◽  
Endogenous Proteins ◽  
Membrane Components

The misfolding and aggregation of proteins is the neuropathological hallmark of numerous diseases including Alzheimer’s disease, Parkinson’s disease, and prion diseases. It is believed that misfolded and abnormal -sheets forms of wild-type proteins are the vectors of these diseases by acting as seeds for the aggregation of endogenous proteins. Cellular prion protein (PrPC) is a glycosyl-phosphatidyl-inositol (GPI) anchored glycoprotein which is able to misfold to a pathogenic isoform PrPSc, the causative agent of prion diseases which present as sporadic, dominantly inherited and transmissible infectious disorders. Increasing evidence highlight the importance of prion-like seeding as a mechanism for pathological spread in Alzheimer’s disease and tauophaty, as well as other neurodegenerative disorders. Here, we report the latest findings on the mechanisms controlling protein folding, focusing on the ER quality control of GPI-anchored proteins and describe the “prion-like” properties of amyloid- and tau assemblies. Furthermore, we highlight the importance of pathogenic assemblies interactions with protein and lipid membrane components and their implications in both prion and Alzheimer’s diseases.

scholarly journals A novel, resistance-linked ovine PrP variant and its equivalent mouse variant modulate the in vitro cell-free conversion of rPrP to PrPres

2006 ◽  
Vol 87 (12) ◽  
pp. 3747-3751 ◽  
Author(s):  
Louise Kirby ◽  
Wilfred Goldmann ◽  
Fiona Houston ◽  
Andrew C. Gill ◽  
Jean C. Manson
Keyword(s):  
Amino Acid ◽  
Prion Diseases ◽  
Cellular Prion Protein ◽  
Transmission Characteristics ◽  
Different Types ◽  
A Cell ◽  
Conversion Efficiencies ◽  
Equivalent Variant

Prion diseases are associated with the conversion of the normal cellular prion protein, PrPc, to the abnormal, disease-associated form, PrPSc. This conversion can be mimicked in vitro by using a cell-free conversion assay. It has recently been shown that this assay can be modified to use bacterial recombinant PrP as substrate and mimic the in vivo transmission characteristics of rodent scrapie. Here, it is demonstrated that the assay replicates the ovine polymorphism barriers of scrapie transmission. In addition, the recently identified ovine PrP variant ARL168Q, which is associated with resistance of sheep to experimental BSE, modulates the cell-free conversion of ovine recombinant PrP to PrPres by three different types of PrPSc, reducing conversion efficiencies to levels similar to those of the ovine resistance-associated ARR variant. Also, the equivalent variant in mice (L164) is resistant to conversion by 87V scrapie. Together, these results suggest a significant role for this position and/or amino acid in conversion.

Epitope scanning indicates structural differences in brain-derived monomeric and aggregated mutant prion proteins related to genetic prion diseases

2013 ◽  
Vol 454 (3) ◽  
pp. 417-425 ◽  
Author(s):  
Laura Tapella ◽  
Matteo Stravalaci ◽  
Antonio Bastone ◽  
Emiliano Biasini ◽  
Marco Gobbi ◽  
...  
Keyword(s):  
Prion Protein ◽  
Prion Proteins ◽  
Prion Diseases ◽  
Prnp Gene ◽  
Structural Heterogeneity ◽  
Cellular Prion Protein ◽  
Amyloid Angiopathy ◽  
Wild Type ◽  
Gene Encoding ◽  
Jakob Disease

Genetic Creutzfeldt–Jakob disease, Gerstmann–Sträussler–Scheinker syndrome, fatal familial insomnia and prion protein cerebral amyloid angiopathy are clinically and neuropathologically distinct neurodegenerative diseases linked to mutations in the PRNP gene encoding the cellular prion protein (PrPC). How sequence variants of PRNP encode the information to specify these disease phenotypes is not known. It is suggested that each mutation produces a misfolded variant of PrPC with specific neurotoxic properties. However, structural studies of recombinant PrP did not detect major differences between wild-type and mutant molecules, pointing to the importance of investigating mutant PrPs from mammalian brains. We used surface plasmon resonance and a slot-blot immunoassay to analyse the antibody-binding profiles of soluble and insoluble PrP molecules extracted from the brains of transgenic mice modelling different prion diseases. By measuring the reactivity of monoclonal antibodies against different PrP epitopes, we obtained evidence of conformational differences between wild-type and mutant PrPs, and among different mutants. We detected structural heterogeneity in both monomeric and aggregated PrP, supporting the hypothesis that the phenotype of genetic prion diseases is encoded by mutant PrP conformation and assembly state.

scholarly journals Microbiome Influence in the Pathogenesis of Prion and Alzheimer’s Diseases

2019 ◽  
Vol 20 (19) ◽  
pp. 4704 ◽  
Author(s):  
Valeria D’Argenio ◽  
Daniela Sarnataro
Keyword(s):  
Gut Microbiota ◽  
Neurodegenerative Diseases ◽  
Prion Diseases ◽  
Critical Role ◽  
Cellular Prion Protein ◽  
Wild Type ◽  
Amyloid Fibril Formation ◽  
Aβ Production ◽  
Microglial Inflammation

Misfolded and abnormal β-sheets forms of wild-type proteins, such as cellular prion protein (PrPC) and amyloid beta (Aβ), are believed to be the vectors of neurodegenerative diseases, prion and Alzheimer’s disease (AD), respectively. Increasing evidence highlights the “prion-like” seeding of protein aggregates as a mechanism for pathological spread in AD, tauopathy, as well as in other neurodegenerative diseases, such as Parkinson’s. Mutations in both PrPC and Aβ precursor protein (APP), have been associated with the pathogenesis of these fatal disorders with clear evidence for their pathogenic significance. In addition, a critical role for the gut microbiota is emerging; indeed, as a consequence of gut–brain axis alterations, the gut microbiota has been involved in the regulation of Aβ production in AD and, through the microglial inflammation, in the amyloid fibril formation, in prion diseases. Here, we aim to review the role of microbiome (“the other human genome”) alterations in AD and prion disease pathogenesis.

Recombinant Variants of Tissue-Type Plasminogen Activator Containing Amino Acid Substitutions in the Finger Domain

1992 ◽  
Vol 68 (06) ◽  
pp. 672-677 ◽  
Author(s):  
Hitoshi Yahara ◽  
Keiji Matsumoto ◽  
Hiroyuki Maruyama ◽  
Tetsuya Nagaoka ◽  
Yasuhiro Ikenaka ◽  
...  
Keyword(s):  
Amino Acid ◽  
Plasminogen Activator ◽  
Half Life ◽  
Tissue Type ◽  
Clot Lysis ◽  
Amino Acid Substitutions ◽  
Wild Type ◽  
Plasma Clot ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator

SummaryTissue-type plasminogen activator (t-PA) is a fibrin-specific agent which has been used to treat acute myocardial infarction. In an attempt to clarify the determinants for its rapid clearance in vivo and high affinity for fibrin clots, we produced five variants containing amino acid substitutions in the finger domain, at amino acid residues 7–9, 10–14, 15–19, 28–33, and 37–42. All the variants had a prolonged half-life and a decreased affinity for fibrin of various degrees. The 37–42 variant demonstrated about a 6-fold longer half-life with a lower affinity for fibrin. Human plasma clot lysis assay estimated the fibrinolytic activity of the 37–42 variant to be 1.4-fold less effective than that of the wild-type rt-PA. In a rabbit jugular vein clot lysis model, doses of 1.0 and 0.15 mg/kg were required for about 70% lysis in the wild-type and 37–42 variant, respectively. Fibrinogen was degraded only when the wild-type rt-PA was administered at a dose of 1.0 mg/kg. These findings suggest that the 37–42 variant can be employed at a lower dosage and that it is a more fibrin-specific thrombolytic agent than the wild-type rt-PA.

Rapid Quantification of Prion Proteins

2019 ◽  
Author(s):  
Matthew Healey ◽  
Muttuswamy Sivakumaran ◽  
Mark Platt
Keyword(s):  
Prion Proteins ◽  
Prion Diseases ◽  
Sample Volume ◽  
Cellular Prion Protein ◽  
Dna Aptamer ◽  
Superparamagnetic Beads ◽  
Resistive Pulse ◽  
Large Sample Volume ◽  
Complex Sample ◽  
Neurological Conditions

<p>Prion diseases are a group of fatal transmissible neurological conditions caused by the change in conformation of the normal intrinsic cellular prion protein (PrP<sup>C</sup>) in to the highly ordered insoluble amyloid state conformer (PrP<sup>SC</sup>). We present a rapid assay using Aptamers and Resistive Pulse Sensing, RPS, to extract and quantify proteins from complex sample matrices, demonstrate with the quantification of PrP<sup>c</sup>. We functionalise the surface of superparamagnetic beads, SPBs, with a DNA aptamer. First SPB’s termed P-Beads, are used to pre-concentrate the analyte from a large sample volume. The PrP<sup>c</sup> protein is then eluted from the P-Beads before aptamer modified sensing beads, S-Beads, are added. The velocity of the S-Beads through the nanopore reveals the concentration of the PrP<sup>c</sup> protein. The process is done in under an hour and allows the detection of picomol’s of protein. The technique could be easily adopted to the mutated version of the protein and integrated into clinical workflows for the screening of blood donations and transfusions. </p>

scholarly journals Therapeutic Assay with the Non-toxic C-Terminal Fragment of Tetanus Toxin (TTC) in Transgenic Murine Models of Prion Disease

2021 ◽  
Author(s):  
Marina Betancor ◽  
Laura Moreno-Martínez ◽  
Óscar López-Pérez ◽  
Alicia Otero ◽  
Adelaida Hernaiz ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Neurodegenerative Diseases ◽  
Prion Disease ◽  
Tetanus Toxin ◽  
Neuronal Survival ◽  
Prion Diseases ◽  
Cellular Prion Protein ◽  
Murine Models ◽  
Terminal Fragment ◽  
Lateral Sclerosis

AbstractThe non-toxic C-terminal fragment of the tetanus toxin (TTC) has been described as a neuroprotective molecule since it binds to Trk receptors and activates Trk-dependent signaling, activating neuronal survival pathways and inhibiting apoptosis. Previous in vivo studies have demonstrated the ability of this molecule to increase mice survival, inhibit apoptosis and regulate autophagy in murine models of neurodegenerative diseases such as amyotrophic lateral sclerosis and spinal muscular atrophy. Prion diseases are fatal neurodegenerative disorders in which the main pathogenic event is the conversion of the cellular prion protein (PrPC) into an abnormal and misfolded isoform known as PrPSc. These diseases share different pathological features with other neurodegenerative diseases, such as amyotrophic lateral sclerosis, Parkinson’s disease or Alzheimer’s disease. Hitherto, there are no effective therapies to treat prion diseases. Here, we present a pilot study to test the therapeutic potential of TTC to treat prion diseases. C57BL6 wild-type mice and the transgenic mice Tg338, which overexpress PrPC, were intracerebrally inoculated with scrapie prions and then subjected to a treatment consisting of repeated intramuscular injections of TTC. Our results indicate that TTC displays neuroprotective effects in the murine models of prion disease reducing apoptosis, regulating autophagy and therefore increasing neuronal survival, although TTC did not increase survival time in these models.

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