Inhibition of neuroinflammatory nitric oxide signalling supresses protein glycation and recovers neuronal dysfunction in prion disease

2020 ◽  
Author(s):  
Julie-Myrtille Bourgognon ◽  
Jereme G. Spiers ◽  
Sue Robinson ◽  
Hannah Scheiblich ◽  
Catharine Ortori ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Prion Protein ◽  
Prion Disease ◽  
Protein Misfolding ◽  
Brain Homogenate ◽  
Protein Glycation ◽  
Therapeutic Effects ◽  
Normal Brain ◽  
Gene And Protein Expression ◽  
Nos Inhibitor

Abstract Background: Several neurodegenerative diseases associated with protein misfolding (Alzheimer’s, Parkinson’s disease) exhibit oxidative and nitrergic stress following initiation of neuroinflammatory pathways. Associated nitric oxide (NO)-mediated post-translational modifications impact upon protein functions that can exacerbate pathology. Non-enzymatic and irreversible glycation signalling has been implicated as an underlying pathway that promotes protein misfolding, but the direct interactions between both pathways are poorly understood. Methods: Here we investigated the potential therapeutic effects of supressing neurotoxic NO signalling during early progression of prion disease. Tg37 mice aged 3-4 weeks were inoculated by intracerebral injection with either 1% brain homogenate of Rocky Mountain Laboratory (RML) scrapie prion protein or control normal brain homogenate (NBH). Hippocampal gene and protein expression levels of oxidative and nitrergic stress markers were analysed and electrophysiological characterisations of pyramidal neurons were performed in 6-10 weeks old RML and NBH mice. Mice were injected with a NO synthase (NOS) inhibitor and the time course of disease markers was compared to controls. Electrophysiology, immunoblotting and immunocytochemistry studies were performed to identify the effects of NOS inhibition on neurophysiology, glycation, prion protein misfolding and cell death. Statistical analyses employed two-tailed unpaired Student’s t-test, one-way or two-way ANOVA as required and data were considered significant with P<0.05.Results: Increased neuroinflammatory signalling was observed in mice between 6 and 10 weeks post inoculation (w.p.i.) with scrapie prion protein which was characterised by enhanced nitrergic stress and associated with a decline in hippocampal neuronal function by 9 w.p.i.. Daily in vivo administration of the NOS inhibitor L-NAME between 6 and 9 w.p.i. at 20 mg/kg abolished the functional degeneration of hippocampal neurons in prion mice. We further found that this intervention in diseased mice ameliorated 3-nitrotyrosination of triose-phosphate isomerase, an enzyme involved in the formation of disease-associated glycation signalling. Furthermore, L-NAME application reduced the expression of the receptor for advanced glycation end products and the accumulation of hippocampal prion misfolding. Conclusions: Our data suggest that alleviating nitrergic stress during early phases of neurodegeneration reduces neurotoxic post-translational NO signalling and glycation-assisted prion misfolding in the hippocampus, a mechanism which might be applicable to other protein misfolding neurodegenerative conditions.

scholarly journals Inhibition of neuroinflammatory nitric oxide signaling suppresses glycation and prevents neuronal dysfunction in mouse prion disease

2021 ◽  
Vol 118 (10) ◽  
pp. e2009579118
Author(s):  
Julie-Myrtille Bourgognon ◽  
Jereme G. Spiers ◽  
Sue W. Robinson ◽  
Hannah Scheiblich ◽  
Paul Glynn ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Protein Misfolding ◽  
Hippocampal Neurons ◽  
Therapeutic Potential ◽  
Early Disease ◽  
Nitric Oxide Signaling ◽  
Gene And Protein Expression ◽  
No Signaling ◽  
Nos Inhibitor

Several neurodegenerative diseases associated with protein misfolding (Alzheimer’s and Parkinson’s disease) exhibit oxidative and nitrergic stress following initiation of neuroinflammatory pathways. Associated nitric oxide (NO)-mediated posttranslational modifications impact upon protein functions that can exacerbate pathology. Nonenzymatic and irreversible glycation signaling has been implicated as an underlying pathway that promotes protein misfolding, but the direct interactions between both pathways are poorly understood. Here we investigated the therapeutic potential of pharmacologically suppressing neuroinflammatory NO signaling during early disease progression of prion-infected mice. Mice were injected daily with an NO synthase (NOS) inhibitor at early disease stages, hippocampal gene and protein expression levels of oxidative and nitrergic stress markers were analyzed, and electrophysiological characterization of pyramidal CA1 neurons was performed. Increased neuroinflammatory signaling was observed in mice between 6 and 10 wk postinoculation (w.p.i.) with scrapie prion protein. Their hippocampi were characterized by enhanced nitrergic stress associated with a decline in neuronal function by 9 w.p.i. Daily in vivo administration of the NOS inhibitor L-NAME between 6 and 9 w.p.i. at 20 mg/kg prevented the functional degeneration of hippocampal neurons in prion-diseased mice. We further found that this intervention in diseased mice reduced 3-nitrotyrosination of triose-phosphate isomerase, an enzyme involved in the formation of disease-associated glycation. Furthermore, L-NAME application led to a reduced expression of the receptor for advanced glycation end-products and the diminished accumulation of hippocampal prion misfolding. Our data suggest that suppressing neuroinflammatory NO signaling slows functional neurodegeneration and reduces nitrergic and glycation-associated cellular stress.

scholarly journals PMCA-generated prions from the olfactory mucosa of patients with Fatal Familial Insomnia cause prion disease in mice

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Edoardo Bistaffa ◽  
Alba Marín-Moreno ◽  
Juan Carlos Espinosa ◽  
Chiara Maria Giulia De Luca ◽  
Federico Angelo Cazzaniga ◽  
...  
Keyword(s):  
Prion Protein ◽  
Prion Disease ◽  
Protein Misfolding ◽  
Brain Homogenate ◽  
Olfactory Mucosa ◽  
Fatal Familial Insomnia ◽  
Prpsc Deposition ◽  
Astroglial Activation ◽  
The Brain ◽  
D178n Mutation

Background:Fatal Familial Insomnia (FFI) is a genetic prion disease caused by the D178N mutation in the prion protein gene (PRNP) in coupling phase with methionine at PRNP 129. In 2017, we have shown that the olfactory mucosa (OM) collected from FFI patients contained traces of PrPSc detectable by Protein Misfolding Cyclic Amplification (PMCA).Methods:In this work, we have challenged PMCA-generated products obtained from OM and brain homogenate of FFI patients in BvPrP-Tg407 transgenic mice expressing the bank vole prion protein to test their ability to induce prion pathology.Results:All inoculated mice developed mild spongiform changes, astroglial activation, and PrPSc deposition mainly affecting the thalamus. However, their neuropathological alterations were different from those found in the brain of BvPrP-Tg407 mice injected with raw FFI brain homogenate.Conclusions:Although with some experimental constraints, we show that PrPSc present in OM of FFI patients is potentially infectious.Funding:This work was supported in part by the Italian Ministry of Health (GR-2013-02355724 and Ricerca Corrente), MJFF, ALZ, Alzheimer’s Research UK and the Weston Brain Institute (BAND2015), and Euronanomed III (SPEEDY) to FM; by the Spanish Ministerio de Economía y Competitividad (grant AGL2016-78054-R [AEI/FEDER, UE]) to JMT and JCE; AM-M was supported by a fellowship from the INIA (FPI-SGIT-2015-02).

The neuroepidemiology of human prion disease

2020 ◽  
pp. 367-378
Author(s):  
Patrick JM Urwin ◽  
Anna M Molesworth
Keyword(s):  
Prion Protein ◽  
Prion Disease ◽  
Protein Misfolding ◽  
Prion Diseases ◽  
Prion Protein Gene ◽  
Human Prion Disease ◽  
Disease States ◽  
Jakob Disease ◽  
The Central Nervous System ◽  
Sporadic Disease

Human prion diseases comprise a number of rare and fatal neurodegenerative conditions that result from the accumulation in the central nervous system of an abnormal form of a naturally occurring protein, called the prion protein. The diseases occur in genetic, sporadic, and acquired forms: genetic disease is associated with mutations in the prion protein gene (PRNP); sporadic disease is thought to result from a spontaneous protein misfolding event; acquired disease results from transmission of infection from an animal or another human. The potential transmissibility of the prion in any of these forms, either in disease states or during the incubation period, has implications for public health. Here we focus on Creutzfeldt-Jakob Disease (CJD), including variant Creutzfeldt-Jakob Disease (vCJD), although we will also discuss other forms of human prion disease.

scholarly journals Effect of Non-Concentrated and Concentrated Vaporized Hydrogen Peroxide on Scrapie Prions

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 947
Author(s):  
Akikazu Sakudo ◽  
Risa Yamashiro ◽  
Chihiro Harata
Keyword(s):  
Hydrogen Peroxide ◽  
Prion Protein ◽  
Protein Misfolding ◽  
Soft Mode ◽  
Brain Homogenate ◽  
Proteinase K ◽  
Mouse Bioassay ◽  
Half Cycle ◽  
Cover Glass ◽  
Standard Mode

To date, there have been no studies on the sterilization of prions by non-concentrated and concentrated vaporized hydrogen peroxide (VHP) applied by the same instrument. Here, the effect of the two types of VHP applied using an ES-700 sterilizer on prions was investigated. Brain homogenate from scrapie (Chandler) prion-infected mice was spotted on a cover glass and subjected to ES-700 treatment in soft (non-concentrated VHP from 59% hydrogen peroxide) or standard (concentrated VHP from 80% hydrogen peroxide) mode. Proteinase K-resistant prion protein (PrPres), an indicator of the abnormal isoform of prion protein (PrPSc), was reduced by ES-700 treatment under several conditions: SFT1/4 (soft mode, quarter cycle), SFT1/2 (soft mode, half cycle), SFT1 (soft mode, full cycle), and STD1/2 (standard mode, half cycle). PrPres was detected after the first and second rounds of protein misfolding cyclic amplification (PMCA) of untreated samples, but was undetectable in SFT1/4, SFT1/2, SFT1, and STD1/2 treated samples. In a mouse bioassay, SFT1/2 and STD1/2 treatment of prions significantly prolonged survival time, suggesting that prion infectivity is reduced after ES-700 treatment. In summary, both non-concentrated and concentrated VHP inactivate prions and may be useful for the low-temperature sterilization of prion-contaminated medical devices.

scholarly journals Change in tau phosphorylation associated with neurodegeneration in the ME7 model of prion disease

2010 ◽  
Vol 38 (2) ◽  
pp. 545-551 ◽  
Author(s):  
Ayodeji A. Asuni ◽  
V. Hugh Perry ◽  
Vincent O'Connor
Keyword(s):  
Axonal Transport ◽  
Prion Disease ◽  
Neuronal Loss ◽  
Brain Homogenate ◽  
Tau Phosphorylation ◽  
Synaptic Dysfunction ◽  
Normal Brain ◽  
Hyperphosphorylated Tau ◽  
Ad Alzheimer’S Disease ◽  
End Stage

Hyperphosphorylation of the microtubule-associated protein tau is a significant determinant in AD (Alzheimer's disease), where it is associated with disrupted axonal transport and probably causes synaptic dysfunction. Although less well studied, hyperphosphorylation has been observed in prion disease. We have investigated the expression of hyperphosphorylated tau in the hippocampus of mice infected with the ME7 prion agent. In ME7-infected animals, there is a selective loss of CA1 synapse, first discernable at 13 weeks of disease. There is a potential that dysfunctional axonal transport contributes to this synaptopathy. Thus investigating hyperphosphorylated tau that is dysfunctional in AD could illuminate whether and how they are significant in prion disease. We observed no differences in the levels of phosphorylated tau (using MC1, PHF-1 and CP13 antibodies) in detergent-soluble and detergent-insoluble fractions extracted from ME7- and NBH- (normal brain homogenate) treated animals across disease. In contrast, we observed an increase in phospho-tau staining for several epitopes using immunohistochemistry in ME7-infected hippocampal sections. Although the changes were not of the magnitude seen in AD tissue, clear differences for several phospho-tau species were seen in the CA1 and CA3 of ME7-treated animals (pSer199−202>pSer214>PHF-1 antibody). Temporally, these changes were restricted to animals at 20 weeks and none of the disease-related staining was associated with the axons or dendrites that hold CA1 synapses. These findings suggest that phosphorylation of tau at the epitopes examined does not underpin the early synaptic dysfunction. These data suggest that the changes in tau phosphorylation recorded here and observed by others relate to end-stage prion pathology when early dysfunctions have progressed to overt neuronal loss.

scholarly journals PrP glycoforms are associated in a strain-specific ratio in native PrPSc

2005 ◽  
Vol 86 (9) ◽  
pp. 2635-2644 ◽  
Author(s):  
Azadeh Khalili-Shirazi ◽  
Linda Summers ◽  
Jacqueline Linehan ◽  
Gary Mallinson ◽  
David Anstee ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Prion Protein ◽  
Prion Disease ◽  
Prion Diseases ◽  
Cellular Prion Protein ◽  
Normal Brain ◽  
Western Blots ◽  
Prion Strains ◽  
Specific Manner ◽  
First Time

Prion diseases involve conversion of host-encoded cellular prion protein (PrPC) to a disease-related isoform (PrPSc). Using recombinant human β-PrP, a panel of monoclonal antibodies was produced that efficiently immunoprecipitated native PrPSc and recognized epitopes between residues 93–105, indicating for the first time that this region is exposed in both human vCJD and mouse RML prions. In contrast, monoclonal antibodies raised to human α-PrP were more efficient in immunoprecipitating PrPC than PrPSc, and some of them could also distinguish between different PrP glycoforms. Using these monoclonal antibodies, the physical association of PrP glycoforms was studied in normal brain and in the brains of humans and mice with prion disease. It was shown that while PrPC glycoforms can be selectively immunoprecipitated, the differentially glycosylated molecules of native PrPSc are closely associated and always immunoprecipitate together. Furthermore, the ratio of glycoforms comprising immunoprecipitated native PrPSc from diverse prion strains was similar to those observed on denaturing Western blots. These studies are consistent with the view that the proportion of each glycoform incorporated into PrPSc is probably controlled in a strain-specific manner and that each PrPSc particle contains a mixture of glycoforms.

scholarly journals Significant differences in incubation times in sheep infected with bovine spongiform encephalopathy result from variation at codon 141 in the PRNP gene

2012 ◽  
Vol 93 (12) ◽  
pp. 2749-2756 ◽  
Author(s):  
Boon Chin Tan ◽  
Anthony R. Alejo Blanco ◽  
E. Fiona Houston ◽  
Paula Stewart ◽  
Wilfred Goldmann ◽  
...  
Keyword(s):  
Amino Acid ◽  
Bovine Spongiform Encephalopathy ◽  
Prion Protein ◽  
Protein Misfolding ◽  
Prnp Gene ◽  
Brain Homogenate ◽  
Spongiform Encephalopathy ◽  
Direct Effects ◽  
Prion Infection ◽  
Incubation Periods

The susceptibility of sheep to prion infection is linked to variation in the PRNP gene, which encodes the prion protein. Common polymorphisms occur at codons 136, 154 and 171. Sheep which are homozygous for the A136R154Q171 allele are the most susceptible to bovine spongiform encephalopathy (BSE). The effect of other polymorphisms on BSE susceptibility is unknown. We orally infected ARQ/ARQ Cheviot sheep with equal amounts of BSE brain homogenate and a range of incubation periods was observed. When we segregated sheep according to the amino acid (L or F) encoded at codon 141 of the PRNP gene, the shortest incubation period was observed in LL141 sheep, whilst incubation periods in FF141 and LF141 sheep were significantly longer. No statistically significant differences existed in the expression of total prion protein or the disease-associated isoform in BSE-infected sheep within each genotype subgroup. This suggested that the amino acid encoded at codon 141 probably affects incubation times through direct effects on protein misfolding rates.

scholarly journals Domain-specific quantification of prion protein in cerebrospinal fluid by targeted mass spectrometry

2019 ◽  
Author(s):  
Eric Vallabh Minikel ◽  
Eric Kuhn ◽  
Alexandra R Cocco ◽  
Sonia M Vallabh ◽  
Christina R Hartigan ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cerebrospinal Fluid ◽  
Prion Protein ◽  
Prion Disease ◽  
Multiple Reaction Monitoring ◽  
Disease Process ◽  
Brain Homogenate ◽  
Preclinical Development ◽  
Progressive Dementia ◽  
Intracellular Compartments

AbstractTherapies currently in preclinical development for prion disease seek to lower prion protein (PrP) expression in the brain. Trials of such therapies are likely to rely on quantification of PrP in cerebrospinal fluid (CSF) as a pharmacodynamic biomarker and possibly as a trial endpoint. Studies using PrP ELISA kits have reproducibly shown that CSF PrP is lowered in the symptomatic phase of disease, a potential confounder for reading out the effect of PrP-lowering drugs in symptomatic patients. To date it has been unclear whether the reduced abundance of PrP in CSF results from its incorporation into plaques, retention in intracellular compartments, downregulation as a function of the disease process, or other factors. Because misfolding or proteolytic cleavage could potentially render PrP invisible to ELISA even if its concentration were constant or increasing in disease, we sought to establish an orthogonal method for CSF PrP quantification. We developed a targeted mass spectrometry method based on multiple reaction monitoring (MRM) of nine PrP tryptic peptides quantified relative to known concentrations of isotopically labeled standards. Analytical validation experiments showed process replicate coefficients of variation below 15%, good dilution linearity and recovery, and suitable performance for both CSF and brain homogenate and across humans as well as preclinical species of interest. InN=55 CSF samples from individuals referred to prion surveillance centers with rapidly progressive dementia, all six human PrP peptides, spanning the N- and C-terminal domains of PrP, were uniformly reduced in prion disease cases compared to individuals with non-prion diagnoses. This confirms the findings from ELISA studies, demonstrating that lowered CSF PrP concentration in prion disease is a genuine result of the disease process and not merely an artifact of ELISA-based measurement. We provide a targeted mass spectrometry-based method suitable for preclinical and clinical quantification of CSF PrP as a tool for drug development.

scholarly journals De Novo Generation of a Unique Cervid Prion Strain Using Protein Misfolding Cyclic Amplification

mSphere ◽  
2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Crystal Meyerett-Reid ◽  
A. Christy Wyckoff ◽  
Terry Spraker ◽  
Bruce Pulford ◽  
Heather Bender ◽  
...  
Keyword(s):  
Protein Misfolding ◽  
De Novo ◽  
Brain Homogenate ◽  
Research Community ◽  
Mitigation Strategies ◽  
Northern Europe ◽  
Normal Brain ◽  
Prion Strain ◽  
America South ◽  
Free Ranging

ABSTRACT CWD is the only known TSE that affects free-ranging wildlife, specifically cervids such as elk, deer, moose, caribou, and reindeer. CWD has become endemic in both free-ranging and captive herds in North America, South Korea, and, most recently, northern Europe. The prion research community continues to debate the origins of CWD. Original foci of CWD emergence in Colorado and Wyoming coincident with the sheep TSE scrapie suggest that scrapie prions may have adapted to cervids to cause CWD. However, emerging evidence supports the idea that cervid PrPC may be more prone to misfolding to the pathological isoform. Here we test the hypothesis that cervid PrPC can spontaneously misfold to create de novo prions. Whether CWD can arise spontaneously as a sporadic TSE or represents a new TSE caused by cervid-adapted scrapie prions profoundly impacts surveillance and mitigation strategies. Substantial evidence supports the hypothesis that prions are misfolded, infectious, insoluble, and protease-resistant proteins (PrPRES) devoid of instructional nucleic acid that cause transmissible spongiform encephalopathies (TSEs). Protein misfolding cyclic amplification (PMCA) has provided additional evidence that PrPRes acts as a template that can convert the normal cellular prion protein (PrPC) present in uninfected normal brain homogenate (NBH) into the infectious misfolded PrPRES isoform. Human PrPC has been shown to spontaneously convert to a misfolded pathological state causing sporadic Creutzfeldt-Jakob disease (sCJD). Several investigators have reported spontaneous generation of prions by in vitro assays, including PMCA. Here we tested the rate of de novo generation of cervid prions in our laboratory using our standard PMCA protocol and NBH from transgenic mice expressing cervid PrPC (TgCerPrP mice). We generated de novo prions in rounds 4, 5, and 7 at low cumulative rates of 1.6, 5.0, and 6.7%, respectively. The prions caused infectious chronic wasting disease (CWD) upon inoculation into normal uninfected TgCerPrP mice and displayed unique biochemical characteristics compared to other cervid prion strains. We conclude that PMCA of cervid PrPC from normal brain homogenate spontaneously generated a new cervid prion strain. These data support the potential for cervids to develop sporadic CWD. IMPORTANCE CWD is the only known TSE that affects free-ranging wildlife, specifically cervids such as elk, deer, moose, caribou, and reindeer. CWD has become endemic in both free-ranging and captive herds in North America, South Korea, and, most recently, northern Europe. The prion research community continues to debate the origins of CWD. Original foci of CWD emergence in Colorado and Wyoming coincident with the sheep TSE scrapie suggest that scrapie prions may have adapted to cervids to cause CWD. However, emerging evidence supports the idea that cervid PrPC may be more prone to misfolding to the pathological isoform. Here we test the hypothesis that cervid PrPC can spontaneously misfold to create de novo prions. Whether CWD can arise spontaneously as a sporadic TSE or represents a new TSE caused by cervid-adapted scrapie prions profoundly impacts surveillance and mitigation strategies. Podcast: A podcast concerning this article is available.

A Role for IL-1Receptor Antagonist in the Acute Therapeutic Effects of IVIg?.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2064-2064
Author(s):  
Andrew R. Crow ◽  
Seng Song ◽  
John Freedman ◽  
John W. Semple ◽  
Alan H. Lazarus
Keyword(s):  
Nitric Oxide ◽  
Interleukin 1 ◽  
Serum Levels ◽  
Selective Inhibitor ◽  
Therapeutic Effects ◽  
Wild Type ◽  
Specific Antibodies ◽  
Nos Inhibitor ◽  
Therapeutic Doses

Abstract It has been suggested that IVIg and anti-D may function through the regulation of various cytokines; in particular, significant increases in the anti-inflammatory compound interleukin-1 receptor antagonist (IL-1Ra) have been reported after exposure of patients to IVIg or anti-D. However, the possible role that IL-1Ra may play in the acute therapeutic effects of IVIg or anti-D is unknown. Using a murine model of ITP in which IVIg and anti-RBC-specific antibodies are therapeutically effective, we observed that mice injected with therapeutic doses of IVIg and one anti-RBC antibody (TER-119, which mimics the effects of anti-D) demonstrated increased serum levels of IL-1Ra, reaching peak levels at a time which coincided with an increase in platelet count. Surprisingly, another RBC-specific antibody which also reverses ITP, failed to increase IL-production above basal levels. Thrombocytopenic mice lacking the IL-1 receptor are known to be completely unresponsive to IL-1Ra. These mice responded to both IVIg and TER-119 as successfully as wild-type mice. Injection of mice with as much as 1 mg of recombinant IL-1Ra did not significantly ameliorate thrombocytopenia. To further study the possible indirect role of the IL-1Ra system in the amelioration of murine ITP, we next looked at nitric oxide (NO), an immunoregulatory compound that can be induced by IL-1, stimulate increases in IL-1Ra levels, and has been previously demonstrated to be modulated by IVIg. We report here that treatment of mice with aminoguanidine, an iNOS-selective inhibitor or with L-NAME, a multi-spectrum NOS inhibitor, did not significantly affect the ability of IVIg to ameliorate ITP. These data suggest that while IVIg and TER-119 may mediate the release of IL-1Ra, it is not required for IVIg or anti-RBC antibodies to exert their acute therapeutic effects.

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