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Atypical scrapie is a transmissible spongiform encephalopathy that is rarely diagnosed in living animals. In March 2022, a 7-y-old Herdwick ewe was referred to the Scottish Centre for Production Animal Health and Food Safety because of circling behavior and ill thrift. The ewe had a low body condition score, was obtunded, with a wide-based stance of the pelvic limbs, and was circling to the left. Hematologic, biochemical, and CSF analyses were unremarkable, but postmortem magnetic resonance imaging (MRI) findings were consistent with diffuse, bilateral, and symmetrical atrophy of the forebrain and ventriculomegaly. The clinical signs, the involvement of an individual older ewe, and the MRI results led to the clinical diagnosis of scrapie. Immunohistochemistry on the fixed brain, performed by the U.K. Animal and Plant Health Agency, revealed deposits of PrPSc, which is a specific disease marker of transmissible spongiform encephalopathies, mainly in the cerebellum and at lower concentrations in the cerebrum and obex, consistent with the diagnosis of atypical scrapie. MRI findings in a sheep with atypical scrapie have not been described previously, to our knowledge. Scrapie should be included in the list of clinical differential diagnoses when veterinarians are presented with sheep with progressive neurologic signs of several weeks' duration. [ABSTRACT FROM AUTHOR]

Introduction: According to the neuroinflammatory hypothesis, a cytokine-mediated host innate immune response may be involved in the mechanisms that contribute to the process of neurodegeneration. Specifically, regarding prion diseases, some experimental murine models have evidenced an altered profile of inflammatory intermediaries. However, the local inflammatory response has rarely been assessed, and never in tissues from different natural models throughout the progression of neurodegeneration. Methods: The aim of this study was to use immunohistochemistry (IHC) to in situ assess the temporal protein expression of several cytokines in the cerebellum of sheep suffering from various clinical stages of scrapie. Results and discussion: Clear changes in the expression of most of the assessed markers were observed in the affected sheep compared to the healthy control sheep, and from different stages. In summary, this preliminary IHC study focusing in the Purkinje cell layer changes demonstrate that all cytokines or respective receptors studied (IL-1, IL-1R, IL-2R, IL-6, IL-10R, and TNFαR) except for IFNγR are disease-associated signaling proteins showing an increase or decrease in relation to the progression of clinical disease. In the future, this study will be extended to other inflammatory mediators and brain regions, focusing in particular on the release of these inflammatory mediators by astroglial and microglial populations. [ABSTRACT FROM AUTHOR]

Slovenia submitted a request to the European Commission to be recognised as a Member State with negligible risk of classical scrapie. EFSA has been asked to assess if Slovenia has demonstrated that, between 2016 and 2022, a sufficient number of ovine and caprine animals over 18 months old, representative of those slaughtered, culled or found dead have been tested, and will continue to be tested annually, to provide a 95% confidence of detecting classical scrapie if it is present at a prevalence rate exceeding 0.1%. A risk‐based approach using stochastic scenario tree modelling accounting for surveillance stream and species was applied. Globally, there is still a lack of data on the performance of the approved diagnostic screening tests under field conditions, specifically for sheep. Therefore, alternative scenarios were explored extending the range from the sensitivity (99.6%) provided by the past European Union evaluations to a sensitivity of 50%, more consistent with published data obtained under field conditions in infected goat populations. It was concluded that during the period 2016–2023, Slovenia has tested annually a sufficient number of ovine and caprine animals over 18 months of age, sourced from the NSHC and SHC populations, to ensure a 95% level of confidence of detecting CS if it is present in that population at a prevalence rate exceeding 0.1%, assuming a test sensitivity of 90% or above. The same holds for the years 2016, 2021 and 2023, assuming a test sensitivity of at least 80%. Based on the proposed number of samples for 2024 and future years, Slovenia would continue to meet the testing requirements assuming a test sensitivity of at least 80%. [ABSTRACT FROM AUTHOR]

The recent emergence of chronic wasting disease (CWD) in Europe has become a new public health risk for monitoring of wild and farmed cervids. This disease, due to prions, has proliferated in North America in a contagious manner. In several mammalian species, polymorphisms in the prion protein gene (PRNP) play a crucial role in the susceptibility to prions and their spread. To obtain a reliable picture of the distribution of PRNP polymorphisms in the two most common cervid species in France, we sequenced the open reading frame (ORF) of this gene in 2114 animals, 1116 roe deer (Capreolus capreolus) and 998 red deer (Cervus elaphus). Selection criteria such as historical origin, spatial distribution and sex ratio have been integrated to establish this sample collection. Except for one heterozygous animal with a non-synonymous mutation at codon 37 (G37A), all the 1116 French roe deer were monomorphic. Red deer showed greater variation with two non-synonymous substitutions (T98A; Q226E), three synonymous substitutions (codons 21, 78 and 136) and a new 24pb deletion (Δ69-77). We found significant regional variations between French regions in the frequency of the identified substitutions. After cloning of the PRNP ORF from animals presenting multiple non-synonymous polymorphisms, we identified six haplotypes and obtained a total of twelve genotypes. As in other European countries, we highlighted the apparent homogeneity of PRNP in the French roe deer and the existence of a greater diversity in the red deer. These results were in line with European phylogeographic studies on these two species. [ABSTRACT FROM AUTHOR]

Production of the amyloidogenic prion protein, PrPSc, which forms infectious protein aggregates, or prions, is a key pathogenic event in prion diseases. Functional prion-like protein aggregations, such as the mitochondrial adaptor protein MAVS and the inflammasome component protein ASC, have been identified to play a protective role in viral infections in mammalian cells. In this study, to investigate if PrPSc could play a functional role against external stimuli, we infected prion-infected cells with a neurotropic influenza A virus strain, IAV/WSN. We found that prion-infected cells were highly resistant to IAV/WSN infection. In these cells, NF-κB nuclear translocation was disturbed; therefore, mitochondrial superoxide dismutase (mtSOD) expression was suppressed, and mitochondrial reactive oxygen species (mtROS) was increased. The elevated mtROS subsequently activated NLRP3 inflammasomes, leading to the suppression of IAV/ WSN-induced necroptosis. We also found that prion-infected cells accumulated a portion of PrP molecules in the cytosol, and that the N-terminal potential nuclear translocation signal of PrP impeded NF-κB nuclear translocation. These results suggest that PrPSc might play a functional role in protection against viral infections by stimulating the NLRP3 inflammasome-dependent antivirus mechanism through the cytosolic PrP-mediated disturbance of NF-κB nuclear translocation, which leads to suppression of mtSOD expression and consequently upregulation of the NLRP3 inflammasome activator mtROS. IMPORTANCE Cytosolic PrP has been detected in prion-infected cells and suggested to be involved in the neurotoxicity of prions. Here, we also detected cytosolic PrP in prion-infected cells. We further found that the nuclear translocation of NF-κB was disturbed in prion-infected cells and that the N-terminal potential nuclear translocation signal of PrP expressed in the cytosol disturbed the nuclear translocation of NF-κB. Thus, the N-terminal nuclear translocation signal of cytosolic PrP might play a role in prion neurotoxicity. Prion-like protein aggregates in other protein misfolding disorders, including Alzheimer's disease were reported to play a protective role against various environmental stimuli. We here showed that prion-infected cells were partially resistant to IAV/WSN infection due to the cytosolic PrP-mediated disturbance of the nuclear translocation of NF-κB, which consequently activated NLRP3 inflammasomes after IAV/WSN infection. It is thus possible that prions could also play a protective role in viral infections. [ABSTRACT FROM AUTHOR]

Current diagnostic methods for prion diseases only work in late stages of the disease when neurodegeneration is irreversible. Therefore, biomarkers that can detect the disease before the onset of clinical symptoms are necessary. High-throughput discovery proteomics is of great interest in the search for such molecules. Here we used mass spectrometry to analyse the cerebrospinal fluid proteome in an animal prion disease: preclinical and clinical sheep affected with natural scrapie, and healthy sheep. Interestingly, we found 46 proteins in the preclinical stage that were significantly altered (p

Background: The most common natural prion disease that primarily affects sheep and goats is scrapie. It belongs to a group of disorders known as transmissible spongiform encephalopathies (TSEs), which impact both humans and animals. Aim: The research is aimed to examine and confirm the presence of Scrapie in Libya using immunohistochemistry (IHC) techniques. Methods: Brain samples were collected from thirty-three sheep older than two years of age showing clinical signs resembling to scrapie during the period between 2018 to 2023, regardless of race or gender. Three animals, six months old, healthy, and without any symptoms, were used as negative controls. Different parts of the brain, including obex and cerebellum, were taken from each case. The IHC technique used in this study involved staining with monoclonal antibody L42 and DAB (3,3′-diaminobenzidine) as a chromogenic substrate. Results: The IHC examination showed the expression of prion proteins in brain tissue in twenty-three samples. The staining intensity was markedly observed in the neuronal cell bodies and around blood vessels. Conclusion: The findings of this study provide evidence that Scrapie exists in Libya. [Open Vet J 2024; 14(8.000): 1843-1849]

White-tailed deer are susceptible to scrapie (WTD scrapie) after oronasal inoculation with the classical scrapie agent from sheep. Deer affected by WTD scrapie are difficult to differentiate from deer infected with chronic wasting disease (CWD). To assess the transmissibility of the WTD scrapie agent and tissue phenotypes when further passaged in white-tailed deer, we oronasally inoculated wild-type white-tailed deer with WTD scrapie agent. We found that WTD scrapie and CWD agents were generally similar, although some differences were noted. The greatest differences were seen in bioassays of cervidized mice that exhibited significantly longer survival periods when inoculated with WTD scrapie agent than those inoculated with CWD agent. Our findings establish that white-tailed deer are susceptible to WTD scrapie and that the presence of WTD scrapie agent in the lymphoreticular system suggests the handling of suspected cases should be consistent with current CWD guidelines because environmental shedding may occur.

While protein aggregation is a hallmark of many neurodegenerative diseases, acquiring structural information on protein aggregates inside live cells remains challenging. Traditional microscopy does not provide structural information on protein systems. Routinely used fluorescent protein tags, such as Green Fluorescent Protein (GFP), might perturb native structures. Here, we report a counter‐propagating mid‐infrared photothermal imaging approach enabling mapping of secondary structure of protein aggregates in live cells modeling Huntington's disease. By comparing mid‐infrared photothermal spectra of label‐free and GFP‐tagged huntingtin inclusions, we demonstrate that GFP fusions indeed perturb the secondary structure of aggregates. By implementing spectra with small spatial step for dissecting spectral features within sub‐micrometer distances, we reveal that huntingtin inclusions partition into a β‐sheet‐rich core and a ɑ‐helix‐rich shell. We further demonstrate that this structural partition exists only in cells with the [RNQ+] prion state, while [rnq−] cells only carry smaller β‐rich non‐toxic aggregates. Collectively, our methodology has the potential to unveil detailed structural information on protein assemblies in live cells, enabling high‐throughput structural screenings of macromolecular assemblies. [ABSTRACT FROM AUTHOR]

Background: Chronic intestinal pseudo-obstruction (CIPO) is a type of intestinal dysfunction with symptoms of intestinal blockage but without the actual mechanical obstruction. Currently, there are no drugs available to treat this disease. Herein, we report the characterization of the PrP-SCA7-92Q transgenic (Tg) line as a valuable CIPO mouse model and investigated the tolerability and efficacy of the 5-hydroxytryptamine type-4 receptor (5HT4R) agonist velusetrag as a promising pharmacological treatment for CIPO. Methods: To test the pharmacodynamics of velusetrag, 8-week-old SCA7 Tg mice, which express human mutated Ataxin-7 gene containing 92 CAG repeats under the mouse prion protein promoter, were treated for 5 weeks by oral route with velusetrag at 1 and 3 mg/kg doses or vehicle. Body weight was monitored throughout the treatment. After sacrifice, the small intestine and proximal colon were collected for whole-mount immunostaining. Untreated, age-matched, C57BL/6J mice were also used as controls in comparison with the other experimental groups. Results: Analysis of SCA7 Tg mice showed tissue damage and alterations, mucosal abnormalities, and ulcers in the distal small intestine and proximal colon. Morphological changes were associated with significant neuronal loss, as shown by decreased staining of pan-neuronal markers, and with accumulation of ataxin-7-positive inclusions in cholinergic neurons. Administration of velusetrag reversed intestinal abnormalities, by normalizing tissue damage and re-establishing the normal level of glia/neuron's count in both the small and large intestines. Conclusion: We demonstrated that the PrP-SCA7-92Q Tg line, a model originally developed to mimic spinocerebellar ataxia, is suitable to study CIPO pathology and can be useful in establishing new therapeutic strategies, such as in the case of velusetrag. Our results suggest that velusetrag is a promising compound to treat patients affected by CIPO or intestinal dysmotility disease. [ABSTRACT FROM AUTHOR]

Scrapie is a transmissible spongiform encephalopathy affecting sheep and goats. The prion protein-encoding gene (PRNP) plays a crucial role in determining susceptibility and resistance to scrapie. At the European level, surveillance of scrapie is essential to prevent the spread of the disease to livestock. According to the Regulation EU 2020/772 polymorphisms K222, D/S146 could function as resistance alleles in the genetic management of disease prevention. In Italy, a breeding plan for scrapie eradication has not been implemented for goats. However, surveillance plans based on the PRNP genotype have been developed as a preventive measure for scrapie. This research aimed to describe the polymorphisms at 7 positions within the PRNP gene in 956 goats of the Alpine, Saanen and mixed populations farmed in the Lombardy Region in Italy. PRNP polymorphisms were detected using single nucleotide polymorphism markers included in the Neogen GGP Goat 70 k chip. The K222 allele occurred in all populations, with frequencies ranging from 2.1 to 12.7%. No animals carried the S/D146 resistance allele. However, it has been demonstrated that polymorphisms in the other positions analysed could influence resistance or susceptibility to scrapie outbreaks in different ways. Ten potentially distinct haplotypes were found, and the most prevalent of the three populations was H2, which differed from the wild type (H1) in terms of mutation (S vs P) at codon 240. This study provided additional information on the genetic variability of the PRNP gene in these populations in the Lombardy region of Italy, contributing to the development of genetic control measures for disease prevention. [ABSTRACT FROM AUTHOR]

Background: The most common natural prion disease that primarily affects sheep and goats is scrapie. It belongs to a group of disorders known as transmissible spongiform encephalopathies, which impact both humans and animals. Aim: The research is aimed to examine and confirm the presence of scrapie in Libya using immunohistochemistry (IHC) techniques. Methods: Brain samples were collected from thirty-three sheep older than two years of age showing clinical signs resembling to scrapie during the period between 2018 and 2023, regardless of race or gender. Three animals, six months old, healthy, and without any symptoms, were used as negative controls. Different parts of the brain, including the obex and cerebellum, were taken from each case. The IHC technique used in this study involved staining with monoclonal antibody L42 and DAB (3,3′-diaminobenzidine) as a chromogenic substrate. Results: The IHC examination showed the expression of prion proteins in brain tissue in twenty-three samples. The staining intensity was markedly observed in the neuronal cell bodies and around blood vessels. Conclusion: The findings of this study provide evidence that scrapie exists in Libya. [ABSTRACT FROM AUTHOR]

White-tailed deer are susceptible to scrapie (WTD scrapie) after oronasal inoculation with the classical scrapie agent from sheep. Deer affected by WTD scrapie are difficult to differentiate from deer infected with chronic wasting disease (CWD). To assess the transmissibility of the WTD scrapie agent and tissue phenotypes when further passaged in white-tailed deer, we oronasally inoculated wild-type white-tailed deer with WTD scrapie agent. We found that WTD scrapie and CWD agents were generally similar, although some differences were noted. The greatest differences were seen in bioassays of cervidized mice that exhibited significantly longer survival periods when inoculated with WTD scrapie agent than those inoculated with CWD agent. Our findings establish that white-tailed deer are susceptible to WTD scrapie and that the presence of WTD scrapie agent in the lymphoreticular system suggests the handling of suspected cases should be consistent with current CWD guidelines because environmental shedding may occur. [ABSTRACT FROM AUTHOR]

Introduction: Prion diseases are deadly neurodegenerative disorders in both animals and humans, causing the destruction of neural tissue and inducing behavioral manifestations. Heat shock proteins (Hsps), act as molecular chaperones by supporting the appropriate folding of proteins and eliminating the misfolded proteins as well as playing a vital role in cell signaling transduction, cell cycle, and apoptosis control. SW02 is a potent activator of Hsp 70 kDa (Hsp70). Methods: In the current study, the protective effects of SW02 against prion protein 106-126 (PrP106-126)-induced neurotoxicity in human neuroblastoma cells (SH-SY5Y) were investigated. In addition, the therapeutic effects of SW02 in ME7 scrapie-infected mice were evaluated. Results: The results showed that SW02 treatment significantly increased Hsp70 mRNA expression levels and Hsp70 ATPase activity (p < 0.01). SW02 also significantly inhibited cytotoxicity and apoptosis induced by PrP106-126 (p < 0.01) and promoted neurite extension. In vivo, intraperitoneal administration of SW02 did not show a statistically significant difference in survival time (p = 0.16); however, the SW02-treated group exhibited a longer survival time of 223.6 ± 6.0 days compared with the untreated control group survival time of 217.6 ± 5.4 days. In addition, SW02 reduced the PrPSc accumulation in ME7 scrapie-infected mice at 5 months post-injection (p < 0.05). A significant difference was not observed in GFAP expression, an astrocyte marker, between the treated and untreated groups. Conclusion: In conclusion, the potential therapeutic role of the Hsp70 activator SW02 was determined in the present study and may be a novel and effective drug to mitigate the pathologies of prion diseases and other neurodegenerative diseases. Further studies using a combination of two pharmacological activators of Hsp70 are required to maximize the effectiveness of each intervention. [ABSTRACT FROM AUTHOR]

After the detection of bovine spongiform encephalopathy (BSE), and a zoonotic transmissible spongiform encephalopathy (TSE) caused by the pathological prion protein (PrPSc) in two goats, the investigation of goat prions became of greater interest. Therefore, a broad collection of European goat TSE isolates, including atypical scrapie, CH1641 and goat BSE as reference prion strains were biochemically characterised and subsequently inoculated into seven rodent models for further analysis (already published results of this comprehensive study are reviewed here for comparative reasons). We report here the histopathological and immunohistochemical data of this goat TSE panel, obtained after the first passage in Tgshp IX (tg-shARQ) mice, which overexpress the ovine prion protein. In addition to the clear-cut discrimination of all reference prion strains from the classical scrapie (CS) isolates, we were further able to determine three categories of CS strains. The investigation further indicates the occurrence of sub-strains that slightly resemble distant TSE strains, such as BSE or CH1641, reinforcing the theory that CS is not a single strain but a mixture of sub-strains, existing at varying extents in one isolate. This study further proved that Tgshp IX is a potent and reliable tool for the in-depth characterisation of prion strains. [ABSTRACT FROM AUTHOR]

Creutzfeldt–Jakob Disease (CJD), the most common human prion disease, is associated with pathologic misfolding of the prion protein (PrP), encoded by the PRNP gene. Of human prion disease cases, < 1% were transmitted by misfolded PrP, ~ 15% are inherited, and ~ 85% are sporadic (sCJD). While familial cases are inherited through germline mutations in PRNP, the cause of sCJD is unknown. Somatic mutations have been hypothesized as a cause of sCJD, and recent studies have revealed that somatic mutations accumulate in neurons during aging. To investigate the hypothesis that somatic mutations in PRNP may underlie sCJD, we performed deep DNA sequencing of PRNP in 205 sCJD cases and 170 age-matched non-disease controls. We included 5 cases of Heidenhain variant sporadic CJD (H-sCJD), where visual symptomatology and neuropathology implicate localized initiation of prion formation, and examined multiple regions across the brain including in the affected occipital cortex. We employed Multiple Independent Primer PCR Sequencing (MIPP-Seq) with a median depth of > 5000× across the PRNP coding region and analyzed for variants using MosaicHunter. An allele mixing experiment showed positive detection of variants in bulk DNA at a variant allele fraction (VAF) as low as 0.2%. We observed multiple polymorphic germline variants among individuals in our cohort. However, we did not identify bona fide somatic variants in sCJD, including across multiple affected regions in H-sCJD, nor in control individuals. Beyond our stringent variant-identification pipeline, we also analyzed VAFs from raw sequencing data, and observed no evidence of prion disease enrichment for the known germline pathogenic variants P102L, D178N, and E200K. The lack of PRNP pathogenic somatic mutations in H-sCJD or the broader cohort of sCJD suggests that clonal somatic mutations may not play a major role in sporadic prion disease. With H-sCJD representing a localized presentation of neurodegeneration, this serves as a test of the potential role of clonal somatic mutations in genes known to cause familial neurodegeneration. [ABSTRACT FROM AUTHOR]

More than 650 reversible and irreversible post-translational modifications (PTMs) of proteins have been listed so far. Canonical PTMs of proteins consist of the covalent addition of functional or chemical groups on target backbone aminoacids or the cleavage of the protein itself, giving rise to modified proteins with specific properties in terms of stability, solubility, cell distribution, activity, or interactions with other biomolecules. PTMs of protein contribute to cell homeostatic processes, enabling basal cell functions, allowing the cell to respond and adapt to variations of its environment, and globally maintaining the constancy of the milieu interieur (the body's inner environment) to sustain human health. Abnormal protein PTMs are, however, associated with several disease states, such as cancers, metabolic disorders, or neurodegenerative diseases. Abnormal PTMs alter the functional properties of the protein or even cause a loss of protein function. One example of dramatic PTMs concerns the cellular prion protein (PrPC), a GPI-anchored signaling molecule at the plasma membrane, whose irreversible post-translational conformational conversion (PTCC) into pathogenic prions (PrPSc) provokes neurodegeneration. PrPC PTCC into PrPSc is an additional type of PTM that affects the tridimensional structure and physiological function of PrPC and generates a protein conformer with neurotoxic properties. PrPC PTCC into PrPSc in neurons is the first step of a deleterious sequence of events at the root of a group of neurodegenerative disorders affecting both humans (Creutzfeldt-Jakob diseases for the most representative diseases) and animals (scrapie in sheep, bovine spongiform encephalopathy in cow, and chronic wasting disease in elk and deer). There are currently no therapies to block PrPC PTCC into PrPSc and stop neurodegeneration in prion diseases. Here, we review known PrPC PTMs that influence PrPC conversion into PrPSc. We summarized how PrPC PTCC into PrPSc impacts the PrPC interactome at the plasma membrane and the downstream intracellular controlled protein effectors, whose abnormal activation or trafficking caused by altered PTMs promotes neurodegeneration. We discussed these effectors as candidate drug targets for prion diseases and possibly other neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

This article discusses the role of reactive astrocytes in prion diseases. Astrocytes are important for brain function and maintaining the blood-brain barrier. In prion diseases, reactive astrocytes can have both protective and detrimental effects. They can produce a protein called Mfge8 that helps clear cellular debris, but they can also harm neurons and disrupt the blood-brain barrier. The degree of astrocyte activation is correlated with the severity and progression of the disease. Understanding the mechanisms behind astrocyte reactivity could potentially lead to therapeutic interventions for neurodegenerative processes in prion diseases. [Extracted from the article]

Prion diseases are fatal, infectious, neurodegenerative disorders resulting from accumulation of misfolded cellular prion protein in the brain. Early pathological changes during CNS prion disease also include reactive astrocyte activation with increased CD44 expression, microgliosis, as well as loss of dendritic spines and synapses. CD44 is a multifunctional cell surface adhesion and signalling molecule which is considered to play roles in astrocyte morphology and the maintenance of dendritic spine integrity and synaptic plasticity. However, the role of CD44 in prion disease was unknown. Here we used mice deficient in CD44 to determine the role of CD44 during prion disease. We show that CD44-deficient mice displayed no difference in their response to CNS prion infection when compared to wild type mice. Furthermore, the reactive astrocyte activation and microgliosis that accompanies CNS prion infection was unimpaired in the absence of CD44. Together, our data show that although CD44 expression is upregulated in reactive astrocytes during CNS prion disease, it is dispensable for astrocyte and microglial activation and the development of prion neuropathogenesis. [ABSTRACT FROM AUTHOR]

This article explores the discovery and characterization of bacterial prions, specifically focusing on three examples: CbRho, ChSSB, and RepA-WH1. Bacterial prions are proteins that can adopt a misfolded, self-propagating state, similar to prions found in yeast and mammals. The article discusses the properties and functions of these bacterial prions, including their interactions with chaperone proteins and nucleic acids. It also considers the potential implications of bacterial prions for antimicrobial strategies and their similarities to amyloid diseases in humans. However, more research is needed to fully understand the structures and biology of bacterial prions. [Extracted from the article]

Simple Summary: The shadow of prion protein (Sho) encoded by the shadow of prion protein gene (SPRN) has been implicated in prion disease biology. Here, we identified the SPRN gene sequence and characterized its genetic polymorphisms in ducks. As a result, the duck and chicken Sho amino acid sequences shared 100% identity. Notably, we found an abundance of single nucleotide polymorphisms in the open reading frame of duck SPRN gene, which is comparable to those in prion disease-susceptible species. To date, there has been no evidence of prion disease in ducks to our knowledge. Given that our previous study on the duck prion protein gene suggested several characteristics of potential prion disease susceptibility, this study supports the need for additional experiments to examine the risk of developing prion diseases in ducks. Prion diseases are fatal neurodegenerative disorders characterized by an accumulation of misfolded prion protein (PrPSc) in brain tissues. The shadow of prion protein (Sho) encoded by the shadow of prion protein gene (SPRN) is involved in prion disease progress. The interaction between Sho and PrP accelerates the PrPSc conversion rate while the SPRN gene polymorphisms have been associated with prion disease susceptibility in several species. Until now, the SPRN gene has not been investigated in ducks. We identified the duck SPRN gene sequence and investigated the genetic polymorphisms of 184 Pekin ducks. We compared the duck SPRN nucleotide sequence and the duck Sho protein amino acid sequence with those of several other species. Finally, we predicted the duck Sho protein structure and the effects of non-synonymous single nucleotide polymorphisms (SNPs) using computational programs. We were the first to report the Pekin duck SPRN gene sequence. The duck Sho protein sequence showed 100% identity compared with the chicken Sho protein sequence. We found 27 novel SNPs in the duck SPRN gene. Four amino acid substitutions were predicted to affect the hydrogen bond distribution in the duck Sho protein structure. Although MutPred2 and SNPs&GO predicted that all non-synonymous polymorphisms were neutral or benign, SIFT predicted that four variants, A22T, G49D, A68T, and M105I, were deleterious. To the best of our knowledge, this is the first report about the genetic and structural characteristics of the duck SPRN gene. [ABSTRACT FROM AUTHOR]

Mcm1 is an essential Q/N-rich transcription factor. Q/N-rich proteins interact with each other, and many affect the [PSI+] prion formed by the translation termination factor Sup35 (eRF3). We found that transient MCM1 overexpression increased nonsense suppression in [PSI+] strains and SUP35 transcription. As we had discovered similar effects of another Q/N-rich transcription factor, Sfp1, here we focus on the roles of Mcm1 and Sfp1 in SUP35 expression, as well as on the effects of Sfp1 on the expression of the gene encoding another release factor, Sup45 (eRF1). Mutations in the SUP35 promoter showed that none of the potential Mcm1 binding sites affected the Sup35 protein level or nonsense suppression, even during MCM1 overexpression. Mcm1 itself neither formed aggregates in vivo nor affected Sup35 aggregation. In contrast, a mutation in the Sfp1-binding site decreased Sup35 production and [PSI+] toxicity of excess Sfp1. Mutation of the Sfp1 binding site in the SUP45 promoter lowered SUP45 expression and increased nonsense suppression even more drastically. Our data indicate that the mechanisms of Mcm1 and Sfp1 action differ. While Mcm1 seems unlikely to directly regulate SUP35 expression, Sfp1 appears to act through its binding sites and to directly activate SUP35 expression, which in turn may influence the [PSI+] prion phenotype and toxicity. [ABSTRACT FROM AUTHOR]

Transmissible spongiform encephalopathies (TSEs) are a fatal neurogenerative disease that include Creutzfeldt–Jakob disease in humans, scrapie in sheep and goats, bovine spongiform encephalopathy (BSE), and several others as well as the recently described camel prion disease (CPD). CPD originally was documented in 3.1% of camels examined during an antemortem slaughterhouse inspection in the Ouargla region of Algeria. Of three individuals confirmed for CPD, two were sequenced for the exon 3 of the prion protein gene (PRNP) and were identical to sequences previously reported for Camelus dromedarius. Given that other TSEs, such as BSE, are known to be capable of cross–species transmission and that there is household consumption of meat and milk from Camelus, regulations to ensure camel and human health should be a One Health priority in exporting countries. Although the interspecies transmissibility of CPD currently is unknown, genotypic characterization of Camelus PRNP may be used for predictability of predisposition and potential susceptibility to CPD. Herein, eight breeds of dromedary camels from a previous genetic (mitochondrial DNA and microsatellites) and morphological study were genotyped for PRNP and compared to genotypes from CPD–positive Algerian camels. Sequence data from PRNP indicated that Ethiopian camels possessed 100% sequence identity to CPD–positive camels from Algeria. In addition, the camel PRNP genotype is unique compared to other members of the Orders Cetartiodactyla and Perissodactyla and provides an in–depth phylogenetic analysis of families within Cetartiodactyla and Perissodactyla that was used to infer the evolutionary history of the PRNP gene. [ABSTRACT FROM AUTHOR]

Abstract Slovenia submitted a request to the European Commission to be recognised as a Member State with negligible risk of classical scrapie. EFSA has been asked to assess if Slovenia has demonstrated that, between 2016 and 2022, a sufficient number of ovine and caprine animals over 18 months old, representative of those slaughtered, culled or found dead have been tested, and will continue to be tested annually, to provide a 95% confidence of detecting classical scrapie if it is present at a prevalence rate exceeding 0.1%. A risk‐based approach using stochastic scenario tree modelling accounting for surveillance stream and species was applied. Globally, there is still a lack of data on the performance of the approved diagnostic screening tests under field conditions, specifically for sheep. Therefore, alternative scenarios were explored extending the range from the sensitivity (99.6%) provided by the past European Union evaluations to a sensitivity of 50%, more consistent with published data obtained under field conditions in infected goat populations. It was concluded that during the period 2016–2023, Slovenia has tested annually a sufficient number of ovine and caprine animals over 18 months of age, sourced from the NSHC and SHC populations, to ensure a 95% level of confidence of detecting CS if it is present in that population at a prevalence rate exceeding 0.1%, assuming a test sensitivity of 90% or above. The same holds for the years 2016, 2021 and 2023, assuming a test sensitivity of at least 80%. Based on the proposed number of samples for 2024 and future years, Slovenia would continue to meet the testing requirements assuming a test sensitivity of at least 80%.

IntroductionAccording to the neuroinflammatory hypothesis, a cytokine-mediated host innate immune response may be involved in the mechanisms that contribute to the process of neurodegeneration. Specifically, regarding prion diseases, some experimental murine models have evidenced an altered profile of inflammatory intermediaries. However, the local inflammatory response has rarely been assessed, and never in tissues from different natural models throughout the progression of neurodegeneration.MethodsThe aim of this study was to use immunohistochemistry (IHC) to in situ assess the temporal protein expression of several cytokines in the cerebellum of sheep suffering from various clinical stages of scrapie.Results and discussionClear changes in the expression of most of the assessed markers were observed in the affected sheep compared to the healthy control sheep, and from different stages. In summary, this preliminary IHC study focusing in the Purkinje cell layer changes demonstrate that all cytokines or respective receptors studied (IL-1, IL-1R, IL-2R, IL-6, IL-10R, and TNFαR) except for IFNγR are disease-associated signaling proteins showing an increase or decrease in relation to the progression of clinical disease. In the future, this study will be extended to other inflammatory mediators and brain regions, focusing in particular on the release of these inflammatory mediators by astroglial and microglial populations.

Protein misfolding, aggregation, and spread through the brain are primary drivers of neurodegenerative disease pathogenesis. Phagocytic glia are responsible for regulating the load of pathological proteins in the brain, but emerging evidence suggests that glia may also act as vectors for aggregate spread. Accumulation of protein aggregates could compromise the ability of glia to eliminate toxic materials from the brain by disrupting efficient degradation in the phagolysosomal system. A better understanding of phagocytic glial cell deficiencies in the disease state could help to identify novel therapeutic targets for multiple neurological disorders. Here, we report that mutant huntingtin (mHTT) aggregates impair glial responsiveness to injury and capacity to degrade neuronal debris in male and female adult Drosophila expressing the gene that causes Huntington's disease (HD). mHTT aggregate formation in neurons impairs engulfment and clearance of injured axons and causes accumulation of phagolysosomes in glia. Neuronal mHTT expression induces upregulation of key innate immunity and phagocytic genes, some of which were found to regulate mHTT aggregate burden in the brain. A forward genetic screen revealed Rab10 as a novel component of Draper-dependent phagocytosis that regulates mHTT aggregate transmission from neurons to glia. These data suggest that glial phagocytic defects enable engulfed mHTT aggregates to evade lysosomal degradation and acquire prion-like characteristics. Together, our findings uncover new mechanisms that enhance our understanding of the beneficial and harmful effects of phagocytic glia in HD and other neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Prion diseases are rare and neurodegenerative diseases that are characterized by the misfolding and infectious spread of the prion protein in the brain, causing progressive and irreversible neuronal loss and associated clinical and behavioral manifestations in humans and animals, ultimately leading to death. The brain has a complex network of neurons and glial cells whose crosstalk is critical for function and homeostasis. Although it is established that prion infection of neurons is necessary for clinical disease to occur, debate remains in the field as to the role played by glial cells, namely astrocytes and microglia, and whether these cells are beneficial to the host or further accelerate disease. Here, we review the current literature assessing the complex morphologies of astrocytes and microglia, and the crosstalk between these two cell types, in the prion-infected brain. [ABSTRACT FROM AUTHOR]

This editorial explores the concept of prions, which are proteins that can adopt unconventional conformations and pass these conformations to other proteins. Prions have been associated with various human diseases and have been found in different species, including yeast. The document includes multiple articles that delve into various aspects of prion biology, such as the formation, propagation, and elimination of prions in yeast cells. It also discusses the role of chaperones and other cellular systems in regulating prion formation and propagation. The text highlights the importance of using different experimental approaches to understand the nature and impact of in vivo aggregates. The articles cover topics such as the study of human proteins in yeast, genetic prion diseases, and the analysis of the shadow of prion protein gene in cats. The authors express gratitude to the contributors and reviewers and emphasize the need for further research to develop disease treatment strategies and drug development. They also mention the ongoing discussion about the transmission of prion diseases to humans and the potential role of plants in environmental transmission. [Extracted from the article]

Mesenchymal stem cells (MSCs) have shown promise in the treatment of neurodegenerative diseases such as Alzheimer's, Parkinson's, and epilepsy. They have the ability to differentiate into different cell types and can modulate the inflammatory response, promote neuron survival, and release neurotrophic factors. Stem cells isolated from human dental pulp and exfoliated deciduous teeth are particularly promising for treating neurodegenerative conditions due to their easy extraction process and ability to develop into different types of mature neurons. The link between bone health and brain function is also highlighted, with the bidirectional communication between bones and nerves potentially offering new therapeutic strategies. Additionally, stem cells have been explored as a potential model for studying prion diseases, although further research is needed to determine their efficacy in treating these conditions. Overall, more research is needed to fully understand and apply the therapeutic potential of MSCs in neurodegenerative diseases. [Extracted from the article]

Prions are proteinaceous pathogens responsible for a variety of devastating diseases in mammals, including scrapie in sheep and goats, chronic wasting disease in cervids, and Creutzfeldt–Jakob disease (CJD) in humans. They are characterized by their exceptional persistence to common inactivation procedures. This applies to all possible sources of prion contamination as prions may be present in the tissues and biological fluids of infected individuals. Hence, efficient prion inactivation procedures are still being sought to minimize the risk of intra- or inter-species transmission. In the past, photocatalytic treatment has been proven to be capable of efficiently oxidizing and inactivating prions. In the present study, the efficacy of homogeneous photo-Fenton-based photocatalysis as well as heterogeneous photocatalysis with TiO2 in reducing RML mouse scrapie infectivity was evaluated. Prion inactivation was assessed by means of a bioassay, and the results were confirmed by in vitro experiments. While the prion infectivity of the RML mouse scrapie was reduced after treatment with the photo-Fenton reagent, the heterogeneous photocatalytic treatment of the same prion strain completely eliminated prion infectivity. [ABSTRACT FROM AUTHOR]

Background: Chronic wasting disease (CWD) is a prion disease of captive and free-ranging cervids. Currently, a definitive diagnosis of CWD relies on immunohistochemistry detection of PrPSc in the obex and retropharyngeal lymph node (RPLN) of the affected cervids. For high-throughput screening of CWD in wild cervids, RPLN samples are tested by ELISA followed by IHC confirmation of positive results. Recently, real-time quacking-induced conversion (RT-QuIC) has been used to detect CWD positivity in various types of samples. To develop a blood RT-QuIC assay suitable for CWD diagnosis, this study evaluated the assay sensitivity and specificity with and without ASR1-based preanalytical enrichment and NaI as the main ionic component in assay buffer. Results: A total of 23 platelet samples derived from CWD-positive deer (ELISA + /IHC +) and 30 platelet samples from CWD-negative (ELISA-) deer were tested. The diagnostic sensitivity was 43.48% (NaCl), 65.22% (NaI), 60.87% (NaCl-ASR1) or 82.61% (NaI-ASR1). The diagnostic specificity was 96.67% (NaCl), 100% (NaI), 100% (NaCl-ASR1), or 96.67% (NaI-ASR1). The probability of detecting CWD prion in platelet samples derived from CWD-positive deer was 0.924 (95% CRI: 0.714, 0.989) under NaI-ASR1 experimental condition and 0.530 (95% CRI: 0.156, 0.890) under NaCl alone condition. The rate of amyloid formation (RFA) was greatest under the NaI-ASR1 condition at 10–2 (0.01491, 95% CRI: 0.00675, 0.03384) and 10–3 (0.00629, 95% CRI: 0.00283, 0.01410) sample dilution levels. Conclusions: Incorporation of ASR1-based preanalytical enrichment and NaI as the main ionic component significantly improved the sensitivity of CWD RT-QuIC on deer platelet samples. Blood test by the improved RT-QuIC assay may be used for antemortem and postmortem diagnosis of CWD. [ABSTRACT FROM AUTHOR]

Orb2 the Drosophila homolog of cytoplasmic polyadenylation element binding (CPEB) protein forms prion-like oligomers. These oligomers consist of Orb2A and Orb2B isoforms and their formation is dependent on the oligomerization of the Orb2A isoform. Drosophila with a mutation diminishing Orb2A's prion-like oligomerization forms long-term memory but fails to maintain it over time. Since this prion-like oligomerization of Orb2A plays a crucial role in the maintenance of memory, here, we aim to find what regulates this oligomerization. In an immunoprecipitation-based screen, we identify interactors of Orb2A in the Hsp40 and Hsp70 families of proteins. Among these, we find an Hsp40 family protein Mrj as a regulator of the conversion of Orb2A to its prion-like form. Mrj interacts with Hsp70 proteins and acts as a chaperone by interfering with the aggregation of pathogenic Huntingtin. Unlike its mammalian homolog, we find Drosophila Mrj is neither an essential gene nor causes any gross neurodevelopmental defect. We observe a loss of Mrj results in a reduction in Orb2 oligomers. Further, Mrj knockout exhibits a deficit in long-term memory and our observations suggest Mrj is needed in mushroom body neurons for the regulation of long-term memory. Our work implicates a chaperone Mrj in mechanisms of memory regulation through controlling the oligomerization of Orb2A and its association with the translating ribosomes. Orb2, the Drosophila homolog of CPEB, forms prion-like oligomers that play a crucial role in the maintenance of long-term memory. This study identifies the Hsp40 family chaperone Mrj as a regulator of Orb2 oligomerization and its association with translating ribosomes. [ABSTRACT FROM AUTHOR]

The spread of prion‐like protein aggregates is a common driver of pathogenesis in various neurodegenerative diseases, including Alzheimer's disease (AD) and related Tauopathies. Tau pathologies exhibit a clear progressive spreading pattern that correlates with disease severity. Clinical observation combined with complementary experimental studies has shown that Tau preformed fibrils (PFF) are prion‐like seeds that propagate pathology by entering cells and templating misfolding and aggregation of endogenous Tau. While several cell surface receptors of Tau are known, they are not specific to the fibrillar form of Tau. Moreover, the underlying cellular mechanisms of Tau PFF spreading remain poorly understood. Here, it is shown that the lymphocyte‐activation gene 3 (Lag3) is a cell surface receptor that binds to PFF but not the monomer of Tau. Deletion of Lag3 or inhibition of Lag3 in primary cortical neurons significantly reduces the internalization of Tau PFF and subsequent Tau propagation and neuron‐to‐neuron transmission. Propagation of Tau pathology and behavioral deficits induced by injection of Tau PFF in the hippocampus and overlying cortex are attenuated in mice lacking Lag3 selectively in neurons. These results identify neuronal Lag3 as a receptor of pathologic Tau in the brain，and for AD and related Tauopathies, a therapeutic target. [ABSTRACT FROM AUTHOR]

In filamentous fungi, vegetative cell fusion occurs within and between individuals. These fusions of growing hyphae (anastomosis) from two individuals produce binucleated cells with mixed cytoplasm known as heterokaryons. The fate of heterokaryotic cells was genetically controlled with delicacy by specific loci named het (heterokaryon) or vic (vegetative incompatibility) as a part of self-/nonself-recognition system. When het loci of two individuals are incompatible, the resulting heterokaryotic cells underwent programmed cell death or showed severely impaired fungal growth. In Podospora anserina, het-s is one of at least nine alleles that control heterokaryon incompatibility and the altered protein conformation [Het-s] prion. The present study describes the [Het-s] prion in terms of (1) the historical discovery based on early genetic and physiological studies, (2) architecture built on its common and unique nature compared with other prions, and (3) functions related to meiotic drive and programmed cell death. [ABSTRACT FROM AUTHOR]

The article focuses on the development of potential treatments for prion diseases, emphasizing strategies to remove or block the production of normal prion protein, with ongoing clinical trials showing promise. Topics discussed include the challenges of diagnosing and treating prion diseases, the significance of the Ionis trial targeting prion diseases, and the efforts of researchers like Sonia Vallabh and Eric Minikel to advance therapies for these devastating brain disorders.

Background: Polymorphisms of Plasmodium falciparum chloroquine resistance transporter (pfcrt), Plasmodium falciparum multi-drug resistance 1 (pfmdr1) and Plasmodium falciparum kelch 13-propeller (pfk13) genes are accepted as valid molecular markers of quinoline antimalarials and artemisinins. This study investigated the distribution patterns of these genes in P. falciparum isolates from the areas along the Thai-Myanmar border during the two different periods of antimalarial usage in Thailand. Results: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) were used to detect pfcrt mutations at codons 76, 220, 271, 326, 356, and 371 as well as pfmdr1 mutation at codon 86. The prevalence of pfcrt mutations was markedly high (96.4–99.7%) in samples collected during both periods. The proportions of mutant genotypes (number of mutant/total isolate) at codons 76, 220, 271, 326, 356 and 371 in the isolates collected during 1993–1998 (period 1) compared with 2002–2008 (period 2) were 97.9% (137/140) vs. 97.1% (401/413), 97.9% (140/143) vs. 98.8% (171/173), 97.2% (139/143) vs. 97.1% (333/343), 98.6% (140/142) vs. 99.7% (385/386), 96.4% (134/139) vs. 98.2% (378/385) and 97.8% (136/139) vs. 98.9% (375/379), respectively. Most isolates carried pfmdr1 wild-type at codon 86, with a significant difference in proportions genotypes (number of wild type/total sample) in samples collected during period 1 [92.9% (130/140)] compared with period 2 [96.9% (379/391)]. Investigation of pfmdr1 copy number was performed by real-time PCR. The proportions of isolates carried 1, 2, 3 and 4 or more than 4 copies of pfmdr1 (number of isolates carried correspondent copy number/total isolate) were significantly different between the two sample collecting periods (65.7% (90/137) vs. 87.8% (390/444), 18.2% (25/137) vs. 6.3%(28/444), 5.1% (7/137) vs. 1.4% (6/444) and 11.0% (15/137) vs. 4.5% (20/444), for period 1 vs. period 2, respectively). No pfk13 mutation was detected by nested PCR and nucleotide sequencing in all samples with successful analysis (n = 68). Conclusions: The persistence of pfcrt mutations and pfmdr1 wild-types at codon 86, along with gene amplification in P. falciparum, contributes to the continued resistance of chloroquine and mefloquine in P. falciparum isolates in the study area. Regular surveillance of antimalarial drug resistance in P. falciparum, incorporating relevant molecular markers and treatment efficacy assessments, should be conducted. [ABSTRACT FROM AUTHOR]

New data suggest that the aggregation of misfolded native proteins initiates and drives the pathogenic cascade that leads to Alzheimer's disease (AD) and other age-related neurodegenerative disorders. We propose a unifying single toxin theory of brain neurodegeneration that identifies new targets and approaches to the development of disease-modifying treatments. An extensive body of genetic evidence suggests soluble aggregates of beta-amyloid (Aβ) as the primary neurotoxin in the pathogenesis of AD. New insights from fluid biomarkers, imaging, and clinical studies provide further evidence for the decisive impact of toxic Aβ species in the initiation and progression of AD. Understanding the distinct roles of soluble and insoluble amyloid aggregates on AD pathogenesis has been the key missing piece of the Alzheimer's puzzle. Data from clinical trials with anti-amyloid agents and recent advances in the diagnosis of AD demonstrate that the driving insult in biologically defined AD is the neurotoxicity of soluble Aβ aggregates, called oligomers and protofibrils, rather than the relatively inert insoluble mature fibrils and amyloid plaques. Amyloid oligomers appear to be the primary factor causing the synaptic impairment, neuronal stress, spreading of tau pathology, and eventual cell death that lead to the clinical syndrome of AD dementia. All other biochemical effects and neurodegenerative changes in the brain that are observed in AD are a response to or a downstream effect of this initial toxic insult by oligomers. Other neurodegenerative disorders follow a similar pattern of pathogenesis, in which normal brain proteins with important biological functions become trapped in the aging brain due to impaired clearance and then misfold and aggregate into neurotoxic species that exhibit prion-like behavior. These aggregates then spread through the brain and cause disease-specific neurodegeneration. Targeting the inhibition of this initial step in neurodegeneration by blocking the misfolding and aggregation of healthy proteins has the potential to slow or arrest disease progression, and if treatment is administered early in the course of AD and other neurodegenerative disorders, it may delay or prevent the onset of clinical symptoms. [ABSTRACT FROM AUTHOR]

IntroductionPrion diseases are deadly neurodegenerative disorders in both animals and humans, causing the destruction of neural tissue and inducing behavioral manifestations. Heat shock proteins (Hsps), act as molecular chaperones by supporting the appropriate folding of proteins and eliminating the misfolded proteins as well as playing a vital role in cell signaling transduction, cell cycle, and apoptosis control. SW02 is a potent activator of Hsp 70 kDa (Hsp70).MethodsIn the current study, the protective effects of SW02 against prion protein 106-126 (PrP106-126)-induced neurotoxicity in human neuroblastoma cells (SH-SY5Y) were investigated. In addition, the therapeutic effects of SW02 in ME7 scrapie-infected mice were evaluated.ResultsThe results showed that SW02 treatment significantly increased Hsp70 mRNA expression levels and Hsp70 ATPase activity (p < 0.01). SW02 also significantly inhibited cytotoxicity and apoptosis induced by PrP106-126 (p < 0.01) and promoted neurite extension. In vivo, intraperitoneal administration of SW02 did not show a statistically significant difference in survival time (p = 0.16); however, the SW02-treated group exhibited a longer survival time of 223.6 ± 6.0 days compared with the untreated control group survival time of 217.6 ± 5.4 days. In addition, SW02 reduced the PrPSc accumulation in ME7 scrapie-infected mice at 5 months post-injection (p < 0.05). A significant difference was not observed in GFAP expression, an astrocyte marker, between the treated and untreated groups.ConclusionIn conclusion, the potential therapeutic role of the Hsp70 activator SW02 was determined in the present study and may be a novel and effective drug to mitigate the pathologies of prion diseases and other neurodegenerative diseases. Further studies using a combination of two pharmacological activators of Hsp70 are required to maximize the effectiveness of each intervention.

Abstract Background Prion diseases, also known as transmissible spongiform encephalopathies (TSEs) remain one of the deleterious disorders, which have affected several animal species. Polymorphism of the prion protein (PRNP) gene majorly determines the susceptibility of animals to TSEs. However, only limited studies have examined the variation in PRNP gene in different Nigerian livestock species. Thus, this study aimed to identify the polymorphism of PRNP gene in Nigerian livestock species (including camel, dog, horse, goat, and sheep). We sequenced the open reading frame (ORF) of 65 camels, 31 village dogs and 12 horses from Nigeria and compared with PRNP sequences of 886 individuals retrieved from public databases. Results All the 994 individuals were assigned into 162 haplotypes. The sheep had the highest number of haplotypes (n = 54), and the camel had the lowest (n = 7). Phylogenetic tree further confirmed clustering of Nigerian individuals into their various species. We detected five non-synonymous SNPs of PRNP comprising of G9A, G10A, C11G, G12C, and T669C shared by all Nigerian livestock species and were in Hardy-Weinberg Equilibrium (HWE). The amino acid changes in these five non-synonymous SNP were all “benign” via Polyphen-2 program. Three SNPs G34C, T699C, and C738G occurred only in Nigerian dogs while C16G, G502A, G503A, and C681A in Nigerian horse. In addition, C50T was detected only in goats and sheep. Conclusion Our study serves as the first to simultaneously investigate the polymorphism of PRNP gene in Nigerian livestock species and provides relevant information that could be adopted in programs targeted at breeding for prion diseases resistance.

ABSTRACTPolymorphism of the prion protein gene (PRNP) gene determines an animal’s susceptibility to scrapie. Three polymorphisms at codons 136, 154, and 171 have been linked to classical scrapie susceptibility, although many variants of PRNP have been reported. However, no study has investigated scrapie susceptibility in Nigerian sheep from the drier agro-climate zones. In this study, we aimed to identify PRNP polymorphism in nucleotide sequences of 126 Nigerian sheep by comparing them with public available studies on scrapie-affected sheep. Further, we deployed Polyphen-2, PROVEAN, and AMYCO analyses to determine the structure changes produced by the non-synonymous SNPs. Nineteen (19) SNPs were found in Nigerian sheep with 14 being non-synonymous. Interestingly, one novel SNP (T718C) was identified. There was a significant difference (P

ABSTRACTEighteenth-century England witnessed the emergence of two neurological diseases in animals. Scrapie, a transmissible spongiform encephalopathy, is a fatal neurodegenerative disease of sheep and goats that appears in classical and atypical forms. Reports of classical scrapie in continental Europe with described symptoms date back to 1750 in what is now western Poland. However, two major outbreaks of scrapie appeared in England prior to the 1800s. References to a sheep disease with a resemblance to scrapie first appear in Southwestern England between 1693 and 1722 and in the East Midlands between 1693 and 1706. Concurrent with the descriptions of scrapie in sheep was a neurological disease of deer first appearing in the East of England. Two 18th-century writers remarked on the symptomatic similarities between the sheep and deer neurological diseases. Multiple outbreaks of the unknown deer disease existing as early as 1772 are examined and are identified as rabies.

Misfolded proteins are usually refolded to their functional conformations or degraded by quality control mechanisms. When misfolded proteins evade quality control, they can be sequestered to specific sites within cells to prevent the potential dysfunction and toxicity that arises from protein aggregation. Btn2 and Hsp42 are compartment-specific sequestrases that play key roles in the assembly of these deposition sites. Their exact intracellular functions and substrates are not well defined, particularly since heat stress sensitivity is not observed in deletion mutants. We show here that Btn2 and Hsp42 are required for tolerance to oxidative stress conditions induced by exposure to hydrogen peroxide. Btn2 and Hsp42 act to sequester oxidized proteins into defined PQC sites following ROS exposure and their absence leads to an accumulation of protein aggregates. The toxicity of protein aggregate accumulation causes oxidant sensitivity in btn2 hsp42 sequestrase mutants since overexpression of the Hsp104 disaggregase rescues oxidant tolerance. We have identified the Sup35 translation termination factor as an in vivo sequestrase substrate and show that Btn2 and Hsp42 act to suppress oxidant-induced formation of the yeast [PSI+] prion, which is the amyloid form of Sup35. [PSI+] prion formation in sequestrase mutants does not require IPOD (insoluble protein deposit) localization which is the site where amyloids are thought to undergo fragmentation and seeding to propagate their heritable prion form. Instead, both amorphous and amyloid Sup35 aggregates are increased in btn2 hsp42 mutants consistent with the idea that prion formation occurs at multiple intracellular sites during oxidative stress conditions in the absence of sequestrase activity. Taken together, our data identify protein sequestration as a key antioxidant defence mechanism that functions to mitigate the damaging consequences of protein oxidation-induced aggregation. Author summary: Protein misfolding causes protein aggregation which is the abnormal association of proteins into larger aggregate structures. Protein aggregates can be toxic to cells and have been implicated in a wide variety of diseases. Protein sequestration has emerged as a key defence strategy which protects the proteome against an overload of misfolded proteins by partitioning them and protecting against potential cytotoxic effects. Previous studies have identified sequestrase chaperones that act to triage misfolded proteins to various spatially separated deposit sites in cells. We show here that sequestrases play a key role in mitigating the toxicity of protein aggregates specifically formed in response to oxidative stress. Using a yeast model, we show that sequestrases function to suppress oxidant-induced formation of prions, which are infectious agents formed by amyloid aggregates. Localization to the normal amyloid deposition site, termed the IPOD, is not required for prion formation in sequestrase mutants. The IPOD is thought to act as a site where prion proteins form their heritable form, and we propose that the high localized concentrations of multiple non-specific aggregates increases the likelihood of prion induction. This study has broad implications for understanding the role of oxidative protein damage as a trigger of prion and more general protein aggregate formation in eukaryotic cells. [ABSTRACT FROM AUTHOR]

Objective: Neurofilament light chain (Nf-L) has been used to detect neuroaxonal damage in the brain caused by physical injury or disease. The purpose of this study was to determine if serum Nf-L could be used as a biomarker for pre-symptomatic detection of scrapie in sheep. Methods: Four sheep with prion protein genotype AVQQ were intranasally inoculated with the classical scrapie strain x124. Blood was collected every 4 weeks until 44 weeks post-inoculation, at which point weekly collection commenced. Serum was analyzed using single molecule array (Quanterix SR-X) to evaluate Nf-L concentrations. Results: Scrapie was confirmed in each sheep by testing homogenized brainstem at the level of the obex with a commercially available enzyme immunoassay. Increased serum Nf-L concentrations were identified above the determined cutoff during the last tenth of the respective incubation period for each sheep. Throughout the time course study, PrPSc accumulation was not detected antemortem by immunohistochemistry in rectal tissue at any timepoint for any sheep. RT-QuIC results were inconsistently positive throughout the timepoints tested for each sheep; however, each sheep had at least one timepoint detected positive. When assessing serum Nf-L utility using receiver operator characteristic curves against different clinical parameters, such as asymptomatic and symptomatic (pruritus or neurologic signs), results showed that Nf-L was most useful at being an indicator of disease only late in disease progression when neurologic signs were present. Conclusion: Serum Nf-L concentrations in the cohort of sheep increased as disease progressed; however, serum Nf-L did not increase during the presymptomatic window. The levels increased substantially throughout the final 10% of the animals' scrapie incubation period when other clinical signs were present. Serum Nf-L is not a reliable biomarker for pre-clinical detection of scrapie. [ABSTRACT FROM AUTHOR]

Background: Prion diseases, also known as transmissible spongiform encephalopathies (TSEs) remain one of the deleterious disorders, which have affected several animal species. Polymorphism of the prion protein (PRNP) gene majorly determines the susceptibility of animals to TSEs. However, only limited studies have examined the variation in PRNP gene in different Nigerian livestock species. Thus, this study aimed to identify the polymorphism of PRNP gene in Nigerian livestock species (including camel, dog, horse, goat, and sheep). We sequenced the open reading frame (ORF) of 65 camels, 31 village dogs and 12 horses from Nigeria and compared with PRNP sequences of 886 individuals retrieved from public databases. Results: All the 994 individuals were assigned into 162 haplotypes. The sheep had the highest number of haplotypes (n = 54), and the camel had the lowest (n = 7). Phylogenetic tree further confirmed clustering of Nigerian individuals into their various species. We detected five non-synonymous SNPs of PRNP comprising of G9A, G10A, C11G, G12C, and T669C shared by all Nigerian livestock species and were in Hardy-Weinberg Equilibrium (HWE). The amino acid changes in these five non-synonymous SNP were all "benign" via Polyphen-2 program. Three SNPs G34C, T699C, and C738G occurred only in Nigerian dogs while C16G, G502A, G503A, and C681A in Nigerian horse. In addition, C50T was detected only in goats and sheep. Conclusion: Our study serves as the first to simultaneously investigate the polymorphism of PRNP gene in Nigerian livestock species and provides relevant information that could be adopted in programs targeted at breeding for prion diseases resistance. [ABSTRACT FROM AUTHOR]

Simple Summary: Neurodegenerative diseases, such as Alzheimer's, Parkinson's, and Huntington's diseases, cause immense suffering to patients and their families. Despite an urgent need for therapies, they are still lacking, partly due to an incomplete understanding of the mechanisms involved. For example, it is unknown why specific brain regions are affected while others are not, a feature known as selective vulnerability. A better understanding of how certain regions resist disease, while others fail, could lead to new therapies. This review discusses ten studies that analyze gene expression changes in specific brain cell types as they respond to the early stages of four types of neurodegenerative disease. It concludes with a summary of recurring themes that address questions about the mechanisms behind selective vulnerability. Neurodegenerative diseases (NDs) manifest a wide variety of clinical symptoms depending on the affected brain regions. Gaining insights into why certain regions are resistant while others are susceptible is vital for advancing therapeutic strategies. While gene expression changes offer clues about disease responses across brain regions, the mixture of cell types therein obscures experimental results. In recent years, methods that analyze the transcriptomes of individual cells (e.g., single-cell RNA sequencing or scRNAseq) have been widely used and have provided invaluable insights into specific cell types. Concurrently, transgene-based techniques that dissect cell type-specific translatomes (CSTs) in model systems, like RiboTag and bacTRAP, offer unique advantages but have received less attention. This review juxtaposes the merits and drawbacks of both methodologies, focusing on the use of CSTs in understanding conditions like amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), Alzheimer's disease (AD), and specific prion diseases like fatal familial insomnia (FFI), genetic Creutzfeldt–Jakob disease (gCJD), and acquired prion disease. We conclude by discussing the emerging trends observed across multiple diseases and emerging methods. [ABSTRACT FROM AUTHOR]

Aim: CH1641 was discovered in 1970 as a scrapie isolate that was unlike all other classical strains of scrapie isolated so far. We performed bio‐assays of CH1641 in mice in order to further characterise this specific isolate. Methods: We inoculated the original CH1641 isolate into ovine and bovine prion protein (PrP) transgenic mice as well as wild‐type mice. In addition, we performed cross‐ and back passages between the various mouse lines to examine if one identical prion strain was isolated in all mouse lines or whether multiple prion strains exist in CH1641. Results: We report the first successful transmission of CH1641 to wild‐type RIII mice and via RIII mice to wild‐type VM mice. Unexpectedly, analysis of the protease‐resistant prion protein (PrPres) in wild‐type mice showed a classical scrapie banding pattern differing from the banding pattern of the original CH1641 isolate. Cross‐ and back passages of CH1641 between the various mouse lines confirmed that the same prion strain had been isolated in all mouse lines. Conclusions: The CH1641 isolate consists of a single prion strain but its molecular banding pattern of PrPres differs between wild‐type mice and PrP transgenic mice. Consequently, molecular banding patterns of PrPres should be used with caution in strain typing since they do not solely depend on the properties of the prion strain but also on the host prion protein. [ABSTRACT FROM AUTHOR]

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are fatal neurodegenerative disorders on a disease spectrum that are characterized by the cytoplasmic mislocalization and aberrant phase transitions of prion-like RNA-binding proteins (RBPs). The common accumulation of TAR DNA-binding protein-43 (TDP-43), fused in sarcoma (FUS), and other nuclear RBPs in detergent-insoluble aggregates in the cytoplasm of degenerating neurons in ALS/FTD is connected to nuclear pore dysfunction and other defects in the nucleocytoplasmic transport machinery. Recent advances suggest that beyond their canonical role in the nuclear import of protein cargoes, nuclear-import receptors (NIRs) can prevent and reverse aberrant phase transitions of TDP-43, FUS, and related prion-like RBPs and restore their nuclear localization and function. Here, we showcase the NIR family and how they recognize cargo, drive nuclear import, and chaperone prion-like RBPs linked to ALS/FTD. We also discuss the promise of enhancing NIR levels and developing potentiated NIR variants as therapeutic strategies for ALS/FTD and related neurodegenerative proteinopathies. [ABSTRACT FROM AUTHOR]