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The history of human prion diseases began with the original description, by Hans Gerhard Creutzfeldt and by Alfons Maria Jakob, of patients with a severe brain disease that included speech abnormalities, confusion, and myoclonus, in a disease that was then named Creutzfeldt Jakob disease (CJD). Later, in Papua New Guinea, a disease characterized by trembling was identified, and given the name "Kuru". Neuropathological examination of the brains from CJD and Kuru patients, and of brains of sheep with scrapie disease revealed significant similarities and suggested a possible common mode of infection that, at the time, was thought to derive from an unknown virus that caused slow infections. John Stanley Griffith hypothesized that the agent causing these diseases was "probably a protein without nucleic acid" and, in 1982, Stanley Prusiner reported the identification of a proteinaceous infectious particle (coining the term prion) that was resistant to inactivation methods that were at the time standard for nucleic acids, and identified PrP as the major protein component of the infectious agent in scrapie and in Creutzfeldt-Jakob disease, classifying this also as a prion disease. Interestingly, the prion concept had been previously expanded to yeast proteins capable of replicating their conformation, seeding their own aggregation and transmitting phenotypic information. The prion concept has been more recently expanded to refer to misfolded proteins that are capable of converting a normal form of a protein into an abnormal form. The quest to understand and treat prion diseases has united a specific research community around the topic, and regular meetings (Prion Meetings) have taken place over the years to enable discussions, train junior researchers, and inspire research in the field.

Neurodegenerative diseases are characterised by neuronal loss and abnormal deposition of pathological proteins in the nervous system. Among the most common neurodegenerative diseases are Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease and transmissible spongiform encephalopathies (TSEs). Sleep and circadian rhythm disturbances are one of the most common symptoms in patients with neurodegenerative diseases. Currently, one of the main objectives in the study of TSEs is to try to establish an early diagnosis, as clinical signs do not appear until the damage to the central nervous system is very advanced, which prevents any therapeutic approach. In this paper, we provide the first description of sleep disturbance caused by classical scrapie in clinical and preclinical sheep using polysomnography compared to healthy controls. Fifteen sheep classified into three groups, clinical, preclinical and negative control, were analysed. The results show a decrease in total sleep time as the disease progresses, with significant changes between control, clinical and pre-clinical animals. The results also show an increase in sleep fragmentation in clinical animals compared to preclinical and control animals. In addition, sheep with clinical scrapie show a total loss of Rapid Eye Movement sleep (REM) and alterations in Non Rapid Eyes Movement sleep (NREM) compared to control sheep, demonstrating more shallow sleep. Although further research is needed, these results suggest that prion diseases also produce sleep disturbances in animals and that polysomnography could be a diagnostic tool of interest in clinical and preclinical cases of prion diseases.

Chronic wasting disease (CWD) is a fatal prion disease of the family Cervidae that circulates in both wild and captive cervid populations. This disease threatens the health and economic viability of the captive cervid industry, which raises cervids in contained spaces for purposes such as hunting and breeding. Given the high transmissibility and long incubation period of CWD, the introduction and propagation of the infectious prion protein within and between captive cervid farms could be devastating to individual facilities and to the industry as a whole. Despite this risk, there does not yet exist a literature review that summarizes the scientific knowledge, to date, about CWD spread, surveillance, or control measures. Our review, which focused on peer reviewed, primary research conducted in the United States, sought to address this need by searching Google Scholar, Scopus, and Web of Science with a five-term keyword string containing terms related to the (1) location, (2) species affected, (3) disease, (4) captive cervid industry, and (5) topic of focus. Between the three databases, there were 190 articles that were selected for further examination. Those articles were then read to determine if they were about CWD spread, surveillance, and/or control in captive cervid facilities. The 22 articles that met these inclusion criteria were evaluated in detail and discussed, with recommendations for future collaborative work between captive cervid owners, government agencies, and researchers. This work will help to address, inform, and mitigate the rising problem of CWD spread and establishment.

In mammals the cellular form of the prion protein (PrP C ) is a ubiquitous protein involved in many relevant functions in the central nervous system. In addition to its physiological functions PrP C plays a central role in a group of invariably fatal neurodegenerative disorders collectively called prion diseases. In fact, the protein is a substrate in a process in which it converts into an infectious and pathological form denoted as prion. The protein has a unique primary structure where the unstructured N-terminal moiety possesses characteristic sequences wherein histidines are able to coordinate metal ions, in particular copper ions. These sequences are called octarepeats for their characteristic length. Moreover, a non-octarepeat fifth-copper binding site is present where copper coordination seems to control infectivity. In this review, I will argue that these sequences may play a significant role in modulating prion conversion and replication.

Among the transmissible spongiform encephalopathies (TSEs), chronic wasting disease (CWD) in cervids is now a rising concern in wildlife within Europe, after the detection of the first case in Norway in 2016, in a wild reindeer and until June 2022 a total of 34 cases were described in Norway, Sweden and Finland. The definite diagnosis is post-mortem , performed in target areas of the brain and lymph nodes. Samples are first screened using a rapid test and, if positive, confirmed by immunohistochemistry and Western immunoblotting. The study of the genetics of the prion protein gene, PRNP , has been proved to be a valuable tool for determining the relative susceptibility to TSEs. In the present study, the exon 3 of PRNP gene of 143 samples from red deer ( Cervus elaphus ) and fallow deer ( Dama dama ) of Portugal was analysed. Three single nucleotide polymorphisms (SNPs) were found in red deer - codon A136A, codon T98A, codon Q226E - and no sequence variation was detected in fallow deer. The low genetic diversity found in our samples is compatible with previous studies in Europe. The comparison with results from North America suggests that the free-ranging deer from our study may present susceptibility to CWD, although lack of experimental data and the necessity of continuous survey are necessary to evaluate these populations.

Worldwide, 10-15% human prion disease are genetic and inherited, due to the special mutations or insertions in PRNP gene. Herein, we reported two Chinese patients with rapidly progressive dementia who were referred to the national Creutzfeldt-Jacob disease (CJD) surveillance as suspected CJD. Those two patients displayed sporadic CJD (sCJD)-like clinical phenotype, e.g. rapidly progressive dementia, visional and mental problems, sCJD-associated abnormalities in MRI. A missense mutation was identified in one PRNP allele of these two patients, resulting in a change from serine to asparagine at codon 97 (S97N). RT-QuIC of the cerebrospinal fluid samples from those two cases were positive. It indicates that they are very likely to be prion disease.

Although multiple sclerosis (MS) and multiple system atrophy (MSA) are both characterized by impaired oligodendrocytes (OLs), the aetiological relevance remains obscure. Given inherent stressors affecting OLs, the objective of the present study was to discuss the possible role of amyloidogenic evolvability (aEVO) in these conditions. Hypothetically, in aEVO, protofibrils of amyloidogenic proteins (APs), including β-synuclein and β-amyloid, might form in response to diverse stressors in parental brain. Subsequently, the AP protofibrils might be transmitted to offspring via germ cells in a prion-like fashion. By virtue of the stress information conferred by protofibrillar APs, the OLs in offspring's brain might be more resilient to forthcoming stressors, perhaps reducing MS risk. aEVO could be comparable to a gene for the inheritance of acquired characteristics. On the contrary, during ageing, MSA risk is increased through antagonistic pleiotropy. Consistently, the expression levels of APs are reduced in MS, but are increased in MSA compared to controls. Furthermore, β-synuclein, the non-amyloidogenic homologue of β-synuclein, might exert a buffering effect on aEVO, and abnormal β-synuclein could also increase MS and MSA disease activity. Collectively, a better understanding of the role of aEVO in the OL diseases might lead to novel interventions for such chronic degenerative conditions.

Eighteenth-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.

Introduction: Before the introduction of MRI diffusion-weighted images (DWI), the diagnosis of Creutzfeldt-Jakob disease (CJD) relied upon nonspecific findings including clinical symptoms, EEG abnormalities, and elevated levels of cerebrospinal fluid 14-3-3 protein. Subsequently, the use of DWI has improved diagnostic accuracy, but it sometimes remains difficult to differentiate CJD from encephalitis, epilepsy, and other dementing disorders. The revised diagnostic criteria include real-time quaking-induced conversion (RT-QuIC), detecting small amounts of CJD-specific prion protein, and clinically sensitive DWI. Combining these techniques has further improved diagnostic accuracy, enabling earlier diagnosis., Areas Covered: Herein, the authors review the recent advances in diagnostic methods and revised diagnostic criteria for sporadic CJD. They also discuss other prion diseases, such as variant CJD and chronic wasting disease, where the emergence of new types is a concern., Expert Opinion: Despite improvements in diagnostic methods and criteria, some subtypes of prion disease are still difficult to diagnose, and even the diagnosis using the most innovative RT-QuIC test remains a challenge in terms of accuracy and standardization. However, these revised criteria can be adapted to the emergence of new types of prion diseases. It is essential to continue careful surveillance and update information on the latest prion disease phenotypes.

Hsp104 propagates the yeast prion [ PSI + ], the infectious form of Sup35, by severing the prion seeds, but when Hsp104 is overexpressed, it cures [ PSI + ] in a process that is not yet understood but may be caused by trimming, which removes monomers from the ends of the amyloid fibers. This curing was shown to depend on both the N-terminal domain of Hsp104 and the expression level of various members of the Hsp70 family, which raises the question as to whether these effects of Hsp70 are due to it binding to the Hsp70 binding site that was identified in the N-terminal domain of Hsp104, a site not involved in prion propagation. Investigating this question, we now find, first, that mutating this site prevents both the curing of [ PSI + ] by Hsp104 overexpression and the trimming activity of Hsp104. Second, we find that depending on the specific member of the Hsp70 family binding to the N-terminal domain of Hsp104, both trimming and the curing caused by Hsp104 overexpression are either increased or decreased in parallel. Therefore, the binding of Hsp70 to the N-terminal domain of Hsp104 regulates both the rate of [ PSI + ] trimming by Hsp104 and the rate of [ PSI + ] curing by Hsp104 overexpression.

The cellular isoform of prion protein, designated PrP C , is a membrane glycoprotein expressed most abundantly in the brain, particularly by neurons, and its conformational conversion into the abnormally folded, amyloidogenic isoform, PrP Sc , is an underlying mechanism in the pathogenesis of prion diseases, a group of neurodegenerative disorders in humans and animals. Most cases of these diseases are sporadic and their aetiologies are unknown. We recently found that a neurotropic strain of influenza A virus (IAV/WSN) caused the conversion of PrP C into PrP Sc and the subsequent formation of infectious prions in mouse neuroblastoma cells after infection. These results show that IAV/WSN is the first non-prion pathogen capable of inducing the conversion of PrP C into PrP Sc and propagating infectious prions in cultured neuronal cells, and also provide the intriguing possibility that IAV infection in neurons might be a cause of or be associated with sporadic prion diseases. Here, we present our findings of the IAV/WSN-induced conversion of PrP C into PrP Sc and subsequent propagation of infectious prions, and also discuss the biological significance of the conversion of PrP C into PrP Sc in virus infections.

Creutzfeldt-Jakob disease (CJD) is a rare, fatal disease presenting with rapidly progressive neurological deficits caused by the accumulation of a misfolded form (PrPSc) of prion protein (PrPc). Coronavirus disease 2019 (COVID-19) is a primarily respiratory syndrome caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); many diverse neurological complications have been observed after COVID-19. We describe a young patient developing CJD two months after mild COVID-19. Presenting symptoms were visuospatial deficits and ataxia, evolving into a bedridden state with preserved consciousness and diffuse myoclonus. Diagnostic work-up was suggestive of CJD. The early age of onset and the short interval between respiratory and neurological symptoms might suggest a causal relationship: a COVID-19-related neuroinflammatory state may have induced the misfolding and subsequent aggregation of PrPSc. The present case emphasizes the link between neuroinflammation and protein misfolding. Further studies are needed to establish the role of SARS-CoV-2 as an initiator of neurodegeneration.

Chronic wasting disease (CWD) is a contagious and fatal transmissible spongiform encephalopathy affecting species of the cervidae family. CWD has an expanding geographic range and complex, poorly understood transmission mechanics. CWD is disproportionately prevalent in wild male mule deer and male white-tailed deer. Sex and species influences on CWD prevalence have been hypothesized to be related to animal behaviours that involve deer facial and body exocrine glands. Understanding CWD transmission potential requires a foundational knowledge of the cellular prion protein (PrP C ) in glands associated with cervid behaviours. In this study, we characterized the presence and distribution of PrP C in six integumentary and two non-integumentary tissues of hunter-harvested mule deer ( Odocoileus hemionus ) and white-tailed deer ( O. virginianus ). We report that white-tailed deer expressed significantly more PrP C than their mule deer in the parotid, metatarsal, and interdigital glands. Females expressed more PrP C than males in the forehead and preorbital glands. The distribution of PrP C within the integumentary exocrine glands of the face and legs were localized to glandular cells, hair follicles, epidermis, and immune cell infiltrates. All tissues examined expressed sufficient quantities of PrP C to serve as possible sites of prion initial infection, propagation, and shedding.

Prion diseases are fatal and irreversible neurodegenerative diseases induced by the pathogenic form of the prion protein (PrP Sc ), which is converted from the benign form of the prion protein (PrP C ). These diseases are characterized by an extended asymptomatic incubation period accompanied by continuous conversion of PrP C to PrP Sc . However, to date, the mechanism governing the conversion to PrP Sc in the initial stages of prion disease has not been fully elucidated. We collected transcriptome data from the hippocampus of wild-type mice and prion-infected mice at 8 weeks post injection from the Gene Expression Omnibus and analysed differentially expressed genes and related signalling biological process using bioinformatic tools. We identified a total of 36 differentially expressed genes, including 22 upregulated genes and 14 downregulated genes. In addition, we identified that the cilium-related biological process was enriched in the early stages of prion disease. Furthermore, up- and down-regulated genes were associated with cilium-related cellular components and synapse-related cellular components, respectively. To the best of our knowledge, our study was the first to observe the upregulation of cilium-related genes in the early stages of prion disease.

Chronic wasting disease (CWD) continues to spread in both wild and captive cervid herds in North America and has now been identified in wild reindeer and moose in Norway, Finland and Sweden. There is limited knowledge about the variety and characteristics of isolates or strains of CWD that exist in the landscape and their implications on wild and captive cervid herds. In this study, we evaluated brain samples from two captive elk herds that had differing prevalence, history and timelines of CWD incidence. Site 1 had a 16-year history of CWD with a consistently low prevalence between 5% and 10%. Twelve of fourteen naïve animals placed on the site remained CWD negative after 5 years of residence. Site 2 herd had a nearly 40-year known history of CWD with long-term environmental accrual of prion leading to nearly 100% of naïve animals developing clinical CWD within two to 12 years. Obex samples of several elk from each site were compared for CWD prion strain deposition, genotype in prion protein gene codon 132, and conformational stability of CWD prions. CWD prions in the obex from site 2 had a lower conformational stability than those from site 1, which was independent of prnp genotype at codon 132. These findings suggest the existence of different CWD isolates between the two sites and suggest potential differential disease attack rates for different CWD strains.

Several studies recently showed that ex vivo fibrils from patient or animal tissue were structurally different from in vitro formed fibrils from the same polypeptide chain. Analysis of serum amyloid A (SAA) and Aβ-derived amyloid fibrils additionally revealed that ex vivo fibrils were more protease stable than in vitro fibrils. These observations gave rise to the proteolytic selection hypothesis that suggested that disease-associated amyloid fibrils were selected inside the body by their ability to resist endogenous clearance mechanisms. We here show, for more than twenty different fibril samples, that ex vivo fibrils are more protease stable than in vitro fibrils. These data support the idea of a proteolytic selection of pathogenic amyloid fibril morphologies and help to explain why only few amino acid sequences lead to amyloid diseases, although many, if not all, polypeptide chains can form amyloid fibrils in vitro .

Transformation of astrocytes into reactive states is considered one of the major pathological hallmarks of prion and other neurodegenerative diseases. Recent years witnessed a growing appreciation of the view that reactive astrocytes are intimately involved in chronic neurodegeneration; however, little is known about their role in disease pathogenesis. The current article reviews the progress of the last few years and critically discusses controversial questions of whether reactive astrocytes associated with prion diseases are neurotoxic or neuroprotective and whether bidirectional A1-A2 model is applicable for describing polarization of astrocytes. Moreover, other important topics, including reversibility of a transition to a reactive state, along with the role of microglia and other stimuli in triggering astrocyte activation are reviewed. Defining the role of reactive astrocytes in pathogenesis of neurodegenerative diseases will open unrealized opportunities for developing new therapeutic approaches against prion and other neurodegenerative diseases.

Intermolecular interaction between hPrP and αS was investigated using high-speed atomic force microscopy, dynamic light scattering, and nuclear magnetic resonance. We found that hPrP spontaneously gathered and naturally formed oligomers. Upon addition of monomer αS with a disordered conformation, poly-dispersive property of hPrP was lost, and hetero-dimer formation started quite coherently, and further oligomerization was not observed. Solution structure of hPrP-αS dimer was firstly characterized using hetero-nuclear NMR spectroscopy. In this hetero-dimeric complex, C-terminal helical region of hPrP was in the molten-globule like state, while specific sites including hot spot and C-terminal region of αS selectively interacted with hPrP. Thus αS may suppress amyloidogenesis of hPrP by trapping the hPrP intermediate by the formation of a stable hetero-dimer with hPrP. Abbreviations: hPrP, human prion protein of amino acid residues of 23-231; PrP C , cellular form of prion protein; PrP Sc , scrapie form of prion protein, HS-AFM; high speed atomic force microscopy; αS, α-synuclein; DLS, dynamic light scattering.

Since the discovery of bovine spongiform encephalopathy (BSE), researchers have orally challenged cattle with infected brain material to study various aspects of disease pathogenesis. Unlike most other pathogens, oral BSE challenge does not always result in the expected clinical presentation and pathology. In a recent study, steers were challenged orally with BSE and all developed clinical signs and were sacrificed and tested. However, despite a similar incubation and clinical presentation, one of the steers did not have detectable PrP Sc in its brain. Samples from this animal were analysed for genetic differences as well as for the presence of in vitro PrP Sc seeding activity or infectivity to determine the BSE status of this animal and the potential reasons that it was different. Seeding activity was detected in the brainstem of the abnormal steer but it was approximately one million times less than that found in the normal BSE positive steers. Intra-cranial challenge of bovinized transgenic mice resulted in no transmission of disease. The abnormal steer had different genetic sequences in non-coding regions of the PRNP gene but detection of similar genotypes in Canadian BSE field cases, that showed the expected brain pathology, suggested these differences may not be the primary cause of the abnormal result. Breed composition analysis showed a higher Hereford content in the abnormal steer as well as in two Canadian atypical BSE field cases and several additional abnormal experimental animals. This study could point towards a possible impact of breed composition on BSE pathogenesis.

Chronic Wasting Disease (CWD), a well-described transmissible spongiform encephalopathy of the Cervidae family, is associated with the aggregation of an abnormal isoform (PrP CWD ) of the naturally occurring host prion protein (PrP C ). Variations in the PrP gene ( PRNP ) have been associated with CWD rate of infection and disease progression. We analysed 568 free-ranging white-tailed deer ( Odocoileus virginianus ) from 9 CWD-positive Michigan counties for PRNP polymorphisms. Sampling included 185 CWD-positive, 332 CWD non-detected, and an additional 51 CWD non-detected paired to CWD-positives by sex, age, and harvest location. We found 12 polymorphic sites of which 5 were non-synonymous and resulted in a change in amino acid composition. Thirteen haplotypes were predicted, of which 11 have previously been described. Using logistic regression, consistent with other studies, we found haplotypes C (OR = 0.488, 95% CI = 0.321-0.730, P < 0.001) and F (OR = 0.122, 95% CI = 0.007-0.612, P < 0.05) and diplotype BC (OR = 0.340, 95% CI = 0.154-0.709, P < 0.01) were less likely to be found in deer infected with CWD. As has also been documented in other studies, the presence of a serine at amino acid 96 was less likely to be found in deer infected with CWD (P < 0.001, OR = 0.360 and 95% CI = 0.227-0.556). Identification of PRNP polymorphisms associated with reduced vulnerability to CWD in Michigan deer and their spatial distribution can help managers design surveillance programmesand identify and prioritize areas for CWD management.

Sporadic Creutzfeldt-Jakob Disease (sCJD) rarely affects women of childbearing age. There is currently no evidence of vertical transmission. Given the biosafety implications of performing Caesarean sections (C-section) in these patients, we used sensitive real-time quaking-induced conversion (RT-QuIC) assays to test for the infectious prion protein (PrP Sc ) in products of gestation. A 35-year-old woman with sCJD presented in her 10 th gestational week with an eight month history of progressive cognitive impairment. During C-section, amniotic fluid, cord blood and placental tissue were collected and analysed using RT-QuIC protocols adapted for use with these tissues. The patient's diagnosis of sCJD, MM2 subtype, was confirmed at autopsy. There were borderline positive results in one sampled area of the placenta, but otherwise the cord blood and amniotic fluid were negative on our RT-QuIC assays. A healthy baby was delivered via C-section at 36 weeks and 3 days gestational age, with no evidence of neurological disease to date. We conclude that precautions should be taken with products of gestation, but the level of PrP Sc is extremely low.

Formation of higher-order supramolecular complexes has emerged as a common principle underlying activity of a number of immune and regulated cell-death signalling pathways in animals, plants and fungi. Some of these signalosomes employ functional amyloid motifs in their assembly process. The description of such systems in fungi finds its origin in earlier studies on a fungal prion termed [Het-s], originally identified as a non-Mendelian cytoplasmic infectious element. Janine Beisson has been a key contributor to such early studies. Recent work on this and related systems offers a more integrated view framing this prion in a broader picture including related signalling systems described in animals. We propose here an auto-commentary centred on three recent studies on amyloid signalling in microbes. Collectively, these studies increase our understanding of fold conservation in functional amyloids and the structural basis of seeding, highlight the relation of fungal amyloid motifs to mammalian RHIM (RIP homotypic interaction motif) and expand the concept of Nod-like receptor-based amyloid signalosomes to the prokaryote reign.

The mutants of the tumor suppressor protein p53 form protein aggregates. It has been proposed that these aggregates propagate like prions, albeit the detailed mechanism of the propagation is unclear. Our recent study revealed that sulfated glycosaminoglycans, especially highly sulfated domains of heparan sulfate (heparan sulfate S-domains), participate in cancer pathology by mediating transcellular propagation of p53 aggregates., (© 2021 Taylor & Francis Group, LLC.)

The real-time quaking-induced conversion (RT-QuIC) reaction is a sensitive and specific method for detecting prions. However, inhibitory factors present in tissue homogenates can easily interfere with this reaction. To identify the RT-QuIC condition under which low levels of chronic wasting disease (CWD) and bovine spongiform encephalopathy (BSE) prions can be detected in the presence of high concentrations of brain tissue homogenates, reactivities of various recombinant prion proteins (rPrPs) were tested. Among the tested rPrPs, recombinant cervid PrP (rCerPrP) showed a unique reactivity: the reactivity of rCerPrP to CWD and atypical BSE prions was not highly affected by high concentrations of normal brain homogenates. The unique reactivity of rCerPrP disappeared when the N-terminal region (aa 25-93) was truncated. Replacement of aa 23-149 of mouse (Mo) PrP with the corresponding region of CerPrP partially restored the unique reactivity of rCerPrP in RT-QuIC. Replacement of the extreme C-terminal region of MoPrP aa 219-231 to the corresponding region of CerPrP partially conferred the unique reactivity of rCerPrP to rMoPrP, suggesting the involvement of both N- and C-terminal regions. Additionally, rCer N -Mo-Cer C PrP, a chimeric PrP comprising CerPrP aa 25-153, MoPrP aa 150-218, and CerPrP aa 223-233, showed an additive effect of the N- and C-terminal regions. These results provide a mechanistic implication for detecting CWD and atypical BSE prions using rCerPrP and are useful for further improvements of RT-QuIC.

Chronic wasting disease (CWD) affects a broad array of cervid species and continues to be detected in an expanding geographic range. Initially introduced into the Republic of Korea through the importation of CWD-infected elk ( Cervus canadensis ), additional cases of CWD were subsequently detected in farmed Korean elk and sika deer ( Cervus nippon ). Wild and farmed sika deer are found in many regions of Asia, North America, and Europe, although natural transmission to this species has not been detected outside of the Republic of Korea. In this study, the oral transmission of CWD to sika deer was investigated using material from CWD-affected elk. Pathological prion (PrP CWD ) immunoreactivity was detected in oropharyngeal lymphoid tissues of one sika deer at 3.9 months post-inoculation (mpi) and was more widely distributed in a second sika deer examined at 10.9 mpi. The remaining four sika deer progressed to clinical disease between 21 and 24 mpi. Analysis of PrP CWD tissue distribution in clinical sika deer revealed widespread deposition in central and peripheral nervous systems, lymphoreticular tissues, and the gastrointestinal tract. Prion protein gene ( PRNP ) sequences of these sika deer were identical and consistent with those reported in natural sika deer populations. These findings demonstrate the efficient oral transmission of CWD from elk to sika deer.

We previously discovered three carbazole derivatives, GJP14 (1-piperidinylmethyl-2-(1-oxo-6-methyl-1,2,3,4-tetrahydrocarbazol-9-yl)-ethan-1-ol) with anti-prion activity, GJC29 (benzylamino-3-(1,2,3,4-tetrahydrocarbazol-9-yl)-propan-2-ol) with anti-cancer activity, and THC19 (1-piperidinylmethyl-2-(1,2,3,4-tetrahydrocarnazol-9-yl)-ethan-1-ol) with anti-influenza virus activity. During optimization of GJP14 for the anti-prion activity, we discovered a compound, 1-(2,6-difluorobenzylamino)-3-(1,2,3,4-tetrahydrocarbazol-9-yl)-propan-2-ol, termed 5Y, had the most strong anti-prion activity among a series of newly synthesized derivatives. Intriguingly, we noticed that 5Y had also the most strong anti-colon cancer as well as the anti-influenza virus activities among derivatives. No significant toxicity of 5Y was observed. These results demonstrate that 5Y is a multipotent lead compound with unusually wide spectrum, and may be applicable to therapeutics targeting multiple diseases. Abbreviations: MoPrP: mouse prion protein of amino acid residues of 23-231; PrP C : cellular form of prion protein; PrP Sc : scrapie form of prion protein.

Chronic wasting disease is a progressively fatal, horizontally transmissible prion disease affecting several members of the cervid species. Conventional diagnosis relies on ELISA or IHC evaluation using tissues collected post-mortem; however, recent research has focused on newly developed amplification techniques using samples collected antemortem. The present study sought to cross-validate the real-time quaking-induced conversion assay (RT-QuIC) evaluation of rectal biopsies collected from an elk herd with endemic CWD, assessing both binary positive/negative test results as well as relative rates of amplification between laboratories. We found that results were correlative in both categories across all laboratories performing RT-QuIC, as well as to conventional IHC performed at a national reference laboratory. A significantly higher number of positive samples were identified using RT-QuIC, with results seemingly unhindered by low follicle counts. These findings support the continued development and implementation of amplification assays in the diagnosis of prion diseases of veterinary importance, targeting not just antemortem sampling strategies, but post-mortem testing approaches as well.

Fatal Familial Insomnia (FFI) is one of the most popular genetic prion disease (gPrD) in China. Unlike the other types of human prion diseases, FFI patients show distinctive neuropathological characteristics, such as less deposition of PrP Sc , low tissue infectivity and severe neuron losses in some special brain regions. Compared with other gPrDs, the positive reactions of cerebrospinal fluid (CSF) RT-QuIC of FFI patients were markedly low. However, the reactivities of RT-QuIC of the brain tissues, particularly different brain regions, of FFI cases are rarely described. In this study, three different brain regions from three FFI patients were subjected into two kinds of RT-QuIC assays using recombinant hamster PrP23-231 (rHaPrP23-231) and PrP90-231 (rHaPrP90-231) as the substrates, respectively. The results showed that the general RT-QuIC reactivities of the brains from FFI cases were significantly lower than that of sCJD. Analyses of the positive rates and the reactivities (lag time and rfu peak) of RT-QuIC identified that the homogenates of frontal lobe induced the most active reaction, followed by thalamus and callosum. The RT-QuIC reactivity in the tested brain sample was closely associated with the intensity of PK-resistant PrP Sc . Moreover, we also verified that the sensitivity of the RT-QuIC of rHaPrP90-231 was much higher than that of rHaPrP23-231. Those data confirm that brain tissues of FFI patients are able to convert positive reactions in RT-QuIC and show regional-associated positive converting capacities.

Amyloids and their infectious subset, prions, represent fibrillary aggregates with regular structure. They are formed by proteins that are soluble in their normal state. In amyloid form, all or part of the polypeptide sequence of the protein is resistant to treatment with proteinase K (PK). Amyloids can have structural variants, which can be distinguished by the patterns of their digestion by PK. In this review, we describe and compare studies of the resistant cores of various amyloids from different organisms. These data provide insight into the fine structure of amyloids and their variants as well as raise interesting questions, such as those concerning the differences between amyloids obtained ex vivo and in vitro , as well as the manner in which folding of one region of the amyloid can affect other regions.

Chronic wasting disease is a fatal, horizontally transmissible prion disease of cervid species that has been reported in free-ranging and farmed animals in North America, Scandinavia, and Korea. Like other prion diseases, CWD susceptibility is partly dependent on the sequence of the prion protein encoded by the host's PRNP gene; it is unknown if variations in PRNP have any meaningful effects on other aspects of health. Conventional diagnosis of CWD relies on ELISA or IHC testing of samples collected post-mortem, with recent efforts focused on antemortem testing approaches. We report on the conclusions of a study evaluating the role of antemortem testing of rectal biopsies collected from over 570 elk in a privately managed herd, and the results of both an amplification assay (RT-QuIC) and conventional IHC among animals with a several PRNP genotypes. Links between PRNP genotype and potential markers of evolutionary fitness, including pregnancy rates, body condition, and annual return rates were also examined. We found that the RT-QuIC assay identified significantly more CWD positive animals than conventional IHC across the course of the study, and was less affected by factors known to influence IHC sensitivity - including follicle count and PRNP genotype. We also found that several evolutionary markers of fitness were not adversely correlated with specific PRNP genotypes. While the financial burden of the disease in this herd was ultimately unsustainable for the herd owners, our scientific findings and the hurdles encountered will assist future CWD management strategies in both wild and farmed elk and deer.

PRNP genotypes, number of octarepeats (PHGGGWGQ) and indels in the PRNP promoter can influence the progression of prion disease in mammals. We found no relationship between presence of promoter indels in white-tailed deer and mule deer from Nebraska and CWD presence. White-tailed deer with the 95 H allele and G20D mule deer were more likely to be CWD-free, but unlike other studies white-tailed deer with the 96S allele(s) were equally likely to be CWD-free. We provide the first information on PRNP genotypes and indels in the promoter for Key deer (all homozygous 96SS) and Coues deer (lacked 95 H and 96S alleles, but possessed a uniquely high frequency of 103 T). All deer surveyed were homozygous for three tandem octarepeats.

The yeast prion [URE3] propagates as a misfolded amyloid form of the Ure2 protein. Propagation of amyloid-based yeast prions requires protein quality control (PQC) factors, and altering PQC abundance or activity can cure cells of prions. Yeast antiprion systems composed of PQC factors act at normal abundance to restrict establishment of the majority of prion variants that arise de novo While these systems are well described, how they or other PQC factors interact with prion proteins remains unclear. To gain insight into such interactions, we identified mutations outside the Ure2 prion-determining region that destabilize [URE3]. Despite residing in the functional domain, 16 of 17 mutants retained Ure2 activity. Four characterized mutations caused rapid loss of [URE3] yet allowed [URE3] to propagate under prion-selecting conditions. Two sensitized [URE3] to Btn2, Cur1, and Hsp42, but in different ways. Two others reduced amyloid formation in vitro Of these, one impaired prion replication and the other apparently impaired transmission. Thus, widely dispersed sites outside a prion's amyloid-forming region can contribute to prion character, and altering such sites can disrupt prion propagation by altering interactions with PQC factors.