Human genetic prion diseases (gPrDs) are directly associated with mutations and insertions in the PRNP (Prion Protein) gene. We collected and analyzed the data of 218 Chinese gPrD patients identified between Jan 2006 and June 2020. Nineteen different subtypes were identified and gPrDs accounted for 10.9% of all diagnosed PrDs within the same period. Some subtypes of gPrDs showed a degree of geographic association. The age at onset of Chinese gPrDs peaked in the 50-59 year group. Gerstmann-Sträussler-Scheinker syndrome (GSS) and fatal familial insomnia (FFI) cases usually displayed clinical symptoms earlier than genetic Creutzfeldt-Jakob disease (gCJD) patients with point mutations. A family history was more frequently recalled in P105L GSS and D178N FFI patients than T188K and E200K patients. None of the E196A gCJD patients reported a family history. The gCJD cases with point mutations always developed clinical manifestations typical of sporadic CJD (sCJD). EEG examination was not sensitive for gPrDs. sCJD-associated abnormalities on MRI were found in high proportions of GSS and gCJD patients. CSF 14-3-3 positivity was frequently detected in gCJD patients. Increased CSF tau was found in more than half of FFI and T188K gCJD cases, and an even higher proportion of E196A and E200K gCJD patients. 63.6% of P105L GSS cases showed a positive reaction in cerebrospinal fluid RT-QuIC. GSS and FFI cases had longer durations than most subtypes of gCJD. This is one of the largest studies of gPrDs in East Asians, and the illness profile of Chinese gPrDs is clearly distinct. Extremely high proportions of T188K and E196A occur among Chinese gPrDs; these mutations are rarely reported in Caucasians and Japanese.
14-3-3 Proteins/cerebrospinal fluid* ; China ; Creutzfeldt-Jakob Syndrome/genetics* ; Humans ; Mutation/genetics* ; Prion Diseases/genetics* ; Prion Proteins/genetics* ; Prions/genetics* ; tau Proteins/cerebrospinal fluid*

Human prion diseases are fatal neurodegenerative disorders that are characterized by spongiform changes, astrogliosis, and the accumulation of an abnormal prion protein (PrP(Sc)). Approximately 10%-15% of human prion diseases are familial variants that are caused by pathogenic mutations in the prion protein gene (PRNP). Point mutations or the insertions of one or more copies of a 24 bp repeat are associated with familial human prion diseases including familial Creutzfeldt-Jakob disease (CJD), Gerstmann-Straussler-Scheinker syndrome, and fatal familial insomnia. These mutations vary significantly in frequency between countries. Here, we compare the frequency of PRNP mutations between European countries and East Asians. Associations between single nucleotide polymorphisms (SNPs) of several candidate genes including PRNP and CJD have been reported. The SNP of PRNP at codon 129 has been shown to be associated with sporadic, iatrogenic, and variant CJD. The SNPs of several genes other than PRNP have been showed contradictory results. Case-control studies and genome-wide association studies have also been performed to identify candidate genes correlated with variant and/or sporadic CJD. This review provides a general overview of the genetic mutations and polymorphisms that have been analyzed in association with human prion diseases to date.
Europe ; Far East ; Humans ; Mutation ; Polymorphism, Single Nucleotide ; Prion Diseases/epidemiology/*genetics ; Prions/*genetics

Prion diseases, including ovine scrapie, bovine spongiform encephalopathy (BSE), human kuru and Creutzfeldt-Jakob disease (CJD), originate from a conformational change of the normal cellular prion protein (PrPC) into abnormal protease-resistant prion protein (PrPSc). There is concern regarding these prion diseases because of the possibility of their zoonotic infections across species. Mutations and polymorphisms of prion sequences may influence prion-disease susceptibility through the modified expression and conformation of proteins. Rapid determination of susceptibility based on prion-sequence polymorphism information without complex structural and molecular biological analyses may be possible. Information regarding the effects of mutations and polymorphisms on prion-disease susceptibility was collected based on previous studies to classify the susceptibilities of sequences, whereas the BLOSUM62 scoring matrix and the position-specific scoring matrix were utilised to determine the distance of target sequences. The k-nearest neighbour analysis was validated with cross-validation methods. The results indicated that the number of polymorphisms did not influence prion-disease susceptibility, and three and four k-objects showed the best accuracy in identifying the susceptible group. Although sequences with negative polymorphisms showed relatively high accuracy for determination, polymorphisms may still not be an appropriate factor for estimating variation in susceptibility. Discriminant analysis of prion sequences with scoring matrices was attempted as a possible means of determining susceptibility to prion diseases. Further research is required to improve the utility of this method.
Amino Acid Sequence ; Animals ; Discriminant Analysis ; Disease Susceptibility ; Humans ; Mammals/genetics ; Mutation ; Polymorphism, Genetic ; Prion Diseases/genetics ; Prions/chemistry/genetics/*pathogenicity ; Sequence Analysis, DNA

In response to viral infection, RIG-I-like RNA helicases detect viral RNA and signal through the mitochondrial adapter protein VISA. VISA activation leads to rapid activation of transcription factors IRF3 and NF-κB, which collaborate to induce transcription of type I interferon (IFN) genes and cellular antiviral response. It has been demonstrated that VISA is activated by forming prion-like aggregates. However, how this process is regulated remains unknown. Here we show that overexpression of HSC71 resulted in potent inhibition of virus-triggered transcription of IFNB1 gene and cellular antiviral response. Consistently, knockdown of HSC71 had opposite effects. HSC71 interacted with VISA, and negatively regulated virus-triggered VISA aggregation. These findings suggest that HSC71 functions as a check against VISA-mediated antiviral response.
Adaptor Proteins, Signal Transducing ; biosynthesis ; chemistry ; genetics ; metabolism ; Cell Aggregation ; genetics ; GPI-Linked Proteins ; metabolism ; Gene Knockdown Techniques ; HEK293 Cells ; HSC70 Heat-Shock Proteins ; genetics ; metabolism ; Heat-Shock Response ; genetics ; Humans ; Interferon Regulatory Factor-3 ; genetics ; metabolism ; Interferon-beta ; genetics ; NF-kappa B ; genetics ; Prions ; metabolism ; Receptors, Retinoic Acid ; metabolism ; Viruses ; drug effects ; metabolism ; pathogenicity

Bovine spongiform encephalopathy (BSE) is one of the fatal neurodegenerative diseases known as transmissible spongiform encephalopathies (TSEs) caused by infectious prion proteins. Genetic variations correlated with susceptibility or resistance to TSE in humans and sheep have not been reported for bovine strains including those from Holstein, Jersey, and Japanese Black cattle. Here, we investigated bovine prion protein gene (PRNP) variations in Hanwoo cattle [Bos (B.) taurus coreanae], a native breed in Korea. We identified mutations and polymorphisms in the coding region of PRNP, determined their frequency, and evaluated their significance. We identified four synonymous polymorphisms and two non-synonymous mutations in PRNP, but found no novel polymorphisms. The sequence and number of octapeptide repeats were completely conserved, and the haplotype frequency of the coding region was similar to that of other B. taurus strains. When we examined the 23-bp and 12-bp insertion/deletion (indel) polymorphisms in the non-coding region of PRNP, Hanwoo cattle had a lower deletion allele and 23-bp del/12-bp del haplotype frequency than healthy and BSE-affected animals of other strains. Thus, Hanwoo are seemingly less susceptible to BSE than other strains due to the 23-bp and 12-bp indel polymorphisms.
Animals ; Base Sequence ; Cattle ; DNA/genetics ; Encephalopathy, Bovine Spongiform/*genetics ; *Genetic Variation ; Haplotypes ; Prions/*genetics ; Republic of Korea

In order to quantify the curing effects of phenanthridine on yeast prion, we introduced semi-denaturing agarose gel electrophoresis and fluorescence recovery after photobleaching techniques to quantify the curing effects of phenanthridine on yeast prion at the protein and cellular levels with the [PSI+] yeast strain expressing GFP-Sup35p (NGMC). The results showed that these two approaches could precisely quantify the curing effects of phenanthridine on [PSI+] cells. After a treatment for 1 through 5 days with phenanthridine, the curing rates of [PSI+] cells were 0%, 0%, 51.7%, 87.5% and 94.4%, respectively. Meanwhile, we quantified the sizes of Sup35p polymers in phenanthridine induced pink phenotype cells. The aggregation status in 1-2 days phenanthridine treated cells were similar to those in [PSI+] cells, while the aggregation status in 3-5 days phenanthridine treated cells were similar to those in [psi(-)] cells.
Computer Simulation ; Models, Biological ; Peptide Termination Factors ; metabolism ; Phenanthridines ; pharmacology ; Prions ; drug effects ; genetics ; metabolism ; Saccharomyces cerevisiae ; cytology ; drug effects ; metabolism ; Saccharomyces cerevisiae Proteins ; metabolism

OBJECTIVETo create transgenic mice expressing hamster- and human-PRNP as a model for understanding the physiological function and pathology of prion protein (PrP), as well as the mechanism of cross-species transmission of transmissible spongiform encephalopathies (TSEs).

METHODSHamster and human-PRNP transgenic mice were established by conventional methods. The copy number of integrated PRNP in various mouse lines was mapped by real-time PCR. PRNP mRNA and protein levels were determined by semi-quantitative RT-PCR, real-time RT-PCR, and western blot analysis. Histological analyses of transgenic mice were performed by hematoxylin and eosin (H & E) staining and immunohistochemical (IHC) methods.

RESULTSIntegrated PRNP copy number in various mouse lines was 53 (Tg-haPrP1), 18 (Tg-huPrP1), 3 (Tg-huPrP2), and 16 (Tg-huPrP5), respectively. Exogenous PrPs were expressed at both the transcriptional and translational level. Histological assays did not detect any abnormalities in brain or other organs.

CONCLUSIONWe have established one hamster-PRNP transgenic mouse line and three human-PRNP transgenic mouse lines. These four transgenic mouse lines provide ideal models for additional research.

Animals ; Blotting, Western ; Cricetinae ; DNA ; genetics ; Disease Models, Animal ; Humans ; Immunohistochemistry ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Organ Specificity ; Plasmids ; Prion Diseases ; genetics ; Prion Proteins ; Prions ; genetics ; Real-Time Polymerase Chain Reaction ; Transcription, Genetic

OBJECTIVETo break immune tolerance to prion (PrP) proteins using DNA vaccines.

METHODSFour different human prion DNA vaccine candidates were constructed based on the pcDNA3.1 vector: PrP-WT expressing wild-type PrP, Ubiq-PrP expressing PrP fused to ubiquitin, PrP-LII expressing PrP fused to the lysosomal integral membrane protein type II lysosome-targeting signal, and PrP-ER expressing PrP locating the ER. Using a prime-boost strategy, three-doses of DNA vaccine were injected intramuscularly into Balb/c mice, followed by two doses of PrP protein. Two weeks after the last immunization, sera and spleens were collected and PrP-specific humoral and cellular immune responses evaluated by ELISA and ELISPOT tests.

RESULTSHigher levels of serum PrP antibodies were detected in mice vaccinated using the strategy of DNA priming followed by protein boosting. Of these, WT-PrP, Ubiq-PrP, and PrP-LII induced significantly higher humoral responses. ELISPOT tests showed markedly increased numbers of IFN-γ-secreting T cells in mice vaccinated using the strategy of DNA priming followed by protein boosting after stimulation with recombinant PrP23-90 and PrP23-231. PrP-ER induced the strongest T-cell response.

CONCLUSIONPrion vaccines can break tolerance to PrP proteins and induce PrP-specific humoral and cellular immune responses.

Animals ; Antibodies ; immunology ; CHO Cells ; COS Cells ; Cercopithecus aethiops ; Cricetinae ; Cricetulus ; Enzyme-Linked Immunosorbent Assay ; Female ; HeLa Cells ; Humans ; Immune Tolerance ; Interferon-gamma ; immunology ; Lysosomal-Associated Membrane Protein 2 ; genetics ; immunology ; Mice ; Mice, Inbred BALB C ; Peptide Fragments ; immunology ; Prions ; genetics ; immunology ; Receptors, Peptide ; genetics ; immunology ; Recombinant Fusion Proteins ; genetics ; immunology ; Recombinant Proteins ; immunology ; Transfection ; Ubiquitin ; genetics ; immunology ; Vaccines, DNA

Sup35 in its native state is a translation termination factor in Saccharomyces cerevisiae. The prion domain of Sup35p can form amyloid-like proteinaceous fibrils in vitro and in vivo. Furthermore, the in-register cross beta-sheet structure of Sup35p amyloid fibrils is similar to those formed in other species. Therefore, studies on mechanism of Sup35p self-assembly can be an appropriate model to study protein misfolding-related diseases and prion biology. Because of its ability to self-assemble into nanowires, the prion domain of Sup35p has been widely used in biotechnology and nanotechnology.
Amino Acid Sequence ; Amyloid ; chemistry ; metabolism ; Molecular Sequence Data ; Peptide Termination Factors ; chemistry ; Prions ; chemistry ; Protein Conformation ; Saccharomyces cerevisiae ; genetics ; metabolism ; Saccharomyces cerevisiae Proteins ; chemistry

Amyotrophic lateral sclerosis (ALS) is a fatal disease characterized by the premature loss of motor neurons. While the underlying cellular mechanisms of neuron degeneration are unknown, the cytoplasmic aggregation of several proteins is associated with sporadic and familial forms of the disease. Both wild-type and mutant forms of the RNA-binding proteins FUS and TDP-43 accumulate in cytoplasmic inclusions in the neurons of ALS patients. It is not known if these so-called proteinopathies are due to a loss of function or a gain of toxicity resulting from the formation of cytoplasmic aggregates. Here we present a model of FUS toxicity using the yeast Saccharomyces cerevisiae in which toxicity is associated with greater expression and accumulation of FUS in cytoplasmic aggregates. We find that FUS and TDP-43 have a high propensity for co-aggregation, unlike the aggregation patterns of several other aggregation-prone proteins. Moreover, the biophysical properties of FUS aggregates in yeast are distinctly different from many amyloidogenic proteins, suggesting they are not composed of amyloid.
Amyotrophic Lateral Sclerosis ; metabolism ; pathology ; Cell Proliferation ; drug effects ; Cytoplasm ; drug effects ; metabolism ; DNA-Binding Proteins ; genetics ; metabolism ; Detergents ; pharmacology ; Humans ; Kinetics ; Peptides ; metabolism ; Prions ; chemistry ; metabolism ; Protein Binding ; drug effects ; Protein Multimerization ; drug effects ; Protein Structure, Quaternary ; Protein Transport ; RNA-Binding Protein FUS ; chemistry ; genetics ; metabolism ; Saccharomyces cerevisiae ; cytology ; drug effects ; genetics ; metabolism ; Saccharomyces cerevisiae Proteins ; chemistry ; metabolism