Lysine residues are not required for proteasome-mediated proteolysis of cellular prion protein.

Cellular prion protein (PrP) is a glycosylphosphatidylinositol (GPI)-anchored cell-surface protein. The mature cell-surface PrP is internalized and subsequently degraded by lysosomes. Although, proteasomes are proposed to be involved, the precise mechanism of PrP degradation remains uncertain.

Search for Expression Marker Genes That Reflect the Physiological Conditions of Blossom End Enlargement Occurrence in Cucumber.

Blossom end enlargement (BEE) is a postharvest deformation that may be related to the influx of photosynthetic assimilates before harvest. To elucidate the mechanism by which BEE occurs, expression marker genes that indicate the physiological condition of BEE-symptomatic fruit are necessary. First, we discovered that preharvest treatment with a synthetic cytokinin, N-(2-Chloro-4-pyridyl)-N'-phenylurea (CPPU), promoted fruit growth and suppressed BEE occurrence.

Comparison of qualitative and fully automated quantitative tools for classifying severity of white matter hyperintensity.

Objective: In this study, we aimed to compare the Fazekas scoring system and quantitative white matter hyperintensity volume in the classification of white matter hyperintensity severity using a fully automated analysis software to investigate the reliability of quantitative evaluation.

Materials And Methods: Patients with suspected cognitive impairment who underwent medical examinations at our institution between January 2010 and May 2021 were retrospectively examined. White matter hyperintensity volumes were analyzed using fully automated analysis software and Fazekas scoring (scores 0-3).

[Echo Train Length (ETL) of Fluid-attenuated Inversion Recovery (FLAIR) and Extraction Volume of White Matter Hyperintensity Volume in Automated White Matter Signal Analysis].

Purpose: To investigate whether the volume of white matter hyperintensity (WMH) extracted from FLAIR images changes when the imaging parameters of the original images are changed.

Methods: Seven healthy volunteers were imaged by changing the imaging parameter ETL of FLAIR images, and WMHs were extracted and their volumes were calculated by the automatic extraction software. The results were statistically analyzed to examine the relationship (Experiment 1).

Central residues in prion protein PrP are crucial for its conversion into the pathogenic isoform.

Conformational conversion of the cellular prion protein, PrP, into the amyloidogenic isoform, PrP, is a key pathogenic event in prion diseases. However, the conversion mechanism remains to be elucidated. Here, we generated Tg(PrPΔ91-106)-8545/Prnp mice, which overexpress mouse PrP lacking residues 91-106.

Pentosan polysulfate induces low-level persistent prion infection keeping measurable seeding activity without PrP-res detection in Fukuoka-1 infected cell cultures.

Each prion strain has its own characteristics and the efficacy of anti-prion drugs varies. Screening of prion disease therapeutics is typically evaluated by measuring amounts of protease-resistant prion protein (PrP-res). However, it remains unclear whether such measurements correlate with seeding activity, which is evaluated by real-time quaking-induced conversion (RT-QuIC).

Spontaneous generation of distinct prion variants with recombinant prion protein from a baculovirus-insect cell expression system.

Prion diseases are transmissible and progressive neurodegenerative disorders characterized by abnormal prion protein (PrP) accumulation in the central nervous system. Generation of synthetic PrP in a cell-free conversion system and examination of its transmissibility to animals would facilitate testing of the protein-only hypothesis and the understanding of the molecular basis of sporadic prion diseases. In this study, we used recombinant prion protein from a baculovirus-insect cell expression system (Bac-rPrP) and insect cell-derived cofactors to determine whether Bac-rPrP is spontaneously produced in intermittent ultrasonic reactions.

RT-QuIC as ultrasensitive method for prion detection.

Real-time quaking-induced conversion (RT-QuIC) is a cell-free abnormal form of prion protein (PrP) amplification method using recombinant prion protein from Escherichia coli that can measure prion seeding activity in samples with high sensitivity. The advantages of this method are that it is much more sensitive than Western blotting, which is usually used to detect PrP, and that prion seeding activity can be easily quantified by combining it with endpoint dilution of the sample, and that it can be amplified in most species and prion strains. A decade has passed since the development of RT-QuIC, and many studies have been reported that take advantage of its characteristics.

Ethanolamine Is a New Anti-Prion Compound.

Prion diseases are a group of fatal neurodegenerative disorders caused by accumulation of proteinaceous infectious particles, or prions, which mainly consist of the abnormally folded, amyloidogenic prion protein, designated PrP. PrP is produced through conformational conversion of the cellular isoform of prion protein, PrP, in the brain. To date, no effective therapies for prion diseases have been developed.

Dextran sulphate inhibits an association of prions with plasma membrane at the early phase of infection.

The defining characteristic of prion diseases is conversion of a cellular prion protein (PrP) to an abnormal prion protein (PrP). The exogenous attachment of PrP to the surface of a target cell is critical for infection. However, the initial interaction of PrP with the cell surface is poorly characterized.

Strain-Dependent Prion Infection in Mice Expressing Prion Protein with Deletion of Central Residues 91-106.

Conformational conversion of the cellular prion protein, PrP, into the abnormally folded isoform, PrP, is a key pathogenic event in prion diseases. However, the exact conversion mechanism remains largely unknown. Transgenic mice expressing PrP with a deletion of the central residues 91-106 were generated in the absence of endogenous PrP, designated Tg(PrP∆91-106)/ mice and intracerebrally inoculated with various prions.

Impairment of cerebellar long-term depression and GABAergic transmission in prion protein deficient mice ectopically expressing PrPLP/Dpl.

Prion protein (PrP) knockout mice, named as the "Ngsk" strain (Ngsk Prnp mice), show late-onset cerebellar Purkinje cell (PC) degeneration because of ectopic overexpression of PrP-like protein (PrPLP/Dpl). Our previous study indicated that the mutant mice also exhibited alterations in cerebellum-dependent delay eyeblink conditioning, even at a young age (16 weeks of age) when neurological changes had not occurred. Thus, this electrophysiological study was designed to examine the synaptic function of the cerebellar cortex in juvenile Ngsk Prnp mice.

Feasibility studies of radioiodinated pyridyl benzofuran derivatives as potential SPECT imaging agents for prion deposits in the brain.

Introduction: Prion diseases are fatal neurodegenerative disorders caused by the deposition of abnormal prion protein aggregates (PrP) in the central nervous system. This study aimed to evaluate the use of iodinated pyridyl benzofuran (IPBF) derivatives as single-photon emission computed tomography (SPECT) probes for the detection of cerebral PrP deposits.

Methods: In vitro binding assays of IPBF derivatives were carried out in the recombinant mouse prion protein (rMoPrP) and brain sections of mouse-adapted bovine spongiform encephalopathy (mBSE)-infected mice.

Administration of FK506 from Late Stage of Disease Prolongs Survival of Human Prion-Inoculated Mice.

Human prion diseases are etiologically categorized into three forms: sporadic, genetic, and infectious. Sporadic Creutzfeldt-Jakob disease (sCJD) is the most common type of human prion disease that manifests as subacute progressive dementia. No effective therapy for sCJD is currently available.

Discrimination between L-type and C-type bovine spongiform encephalopathy by the strain-specific reactions of real-time quaking-induced conversion.

Real-time quaking-induced conversion (RT-QUIC) assays using Escherichia coli-derived purified recombinant prion protein (rPrP) enable us to amplify a trace amount of the abnormal form of PrP (PrP) from specimens. This technique can be useful for the early diagnosis of both human and animal prion diseases and the assessment of prion contamination. In the present study, we demonstrated that there are strain-specific differences in the RT-QUIC reactions between an atypical form of bovine spongiform encephalopathy (BSE), l-BSE, and classical BSE (C-BSE).

Prion protein interacts with the metabotropic glutamate receptor 1 and regulates the organization of Ca signaling.

Cellular prion protein (PrP) is a membrane protein that is highly conserved among mammals and mainly expressed on the cell surface of neurons. Despite its reported interactions with various membrane proteins, no functional studies have so far been carried out on it, and its physiological functions remain unclear. Neuronal cell death has been observed in a PrP-knockout mouse model expressing Doppel protein, suggesting that PrP might be involved in Ca signaling.

[Elucidation of the Molecular Basis of Abnormal Prion Protein (PrP) Formation in a Cell-Free System Using Baculovirus and Insect Cell-derived Recombinant PrP].

The molecular basis underlying the conversion of normal prion protein (PrP) into abnormal prion protein (PrP) has not been fully elucidated. The protein-misfolding cyclic amplification (PMCA) technique, which can amplify PrP in vitro with the use of intermittent sonication, mimics the process of in vivo PrP replication. Accumulating evidence suggests that co-factors other than PrP may play a crucial role in the faithful replication of PrP.

Estimation of prion infectivity in tissues of cattle infected with atypical BSE by real time-quaking induced conversion assay.

Atypical bovine spongiform encephalopathy (BSE), first identified in 2004, poses a threat due to the potential to spread the disease to cattle and other animals, including humans. Here, we estimated prion titers in various tissues of cattle infected with atypical BSE using a real-time quaking-induced conversion assay that detects amyloid seeding activity of a disease-specific prion protein, PrP, a major component of prions. PrP was detected both in and outside of nerve tissues, and some of the peripheral nerve tissues contained relatively high prion titers.

Development of Radioiodinated Benzofuran Derivatives for Imaging of Prion Deposits in the Brain.

Prion diseases are fatal neurodegenerative disorders associated with the deposition of abnormal prion protein aggregates (PrP) in the brain tissue. Here, we report the development of I-labeled iodobenzofuran (IBF) derivatives as single photon emission computed tomography (SPECT) imaging probes to detect cerebral PrP deposits. We synthesized and radioiodinated several 5-IBF and 6-IBF derivatives.

Whole genome characterisation of G11P[25] and G9P[19] rotavirus A strains from adult patients with diarrhoea in Nepal.

Rotavirus A (RVA) causes acute diarrhoea in children and less frequently in adults. However, the knowledge about the genotype distribution of RVA strains circulating in adults is limited particularly in developing countries. This study aimed to characterise the RVA strains detected from adult patients with diarrhoea in Nepal.

Type I interferon protects neurons from prions in in vivo models.

Infectious prions comprising abnormal prion protein, which is produced by structural conversion of normal prion protein, are responsible for transmissible spongiform encephalopathies including Creutzfeldt-Jakob disease in humans. Prions are infectious agents that do not possess a genome and the pathogenic protein was not thought to evoke any immune response. Although we previously reported that interferon regulatory factor 3 (IRF3) was likely to be involved in the pathogenesis of prion diseases, suggesting the protective role of host innate immune responses mediated by IRF3 signalling, this remained to be clarified.

Proteomic approach to profiling immune complex antigens in cerebrospinal fluid samples from patients with central nervous system autoimmune diseases.

Background: Immune complexes (ICs) may clearly reflect immunological abnormalities caused by disease, especially for autoimmune diseases. Although ICs have been detected in cerebrospinal fluid (CSF) from patients with CNS autoimmune diseases, identities of antigens in such ICs have not been comprehensively determined.

Methods: We used immune complexome analysis, in which nano-liquid chromatography-tandem mass spectrometry is employed to comprehensively identify antigens incorporated into ICs in biological fluids, to characterize ICs in CSF samples from patients with CNS autoimmune diseases, and to find disease-specific IC antigen to a certain CNS autoimmune disease.

Identification of Alprenolol Hydrochloride as an Anti-prion Compound Using Surface Plasmon Resonance Imaging.

Prion diseases are transmissible neurodegenerative disorders of humans and animals, which are characterized by the aggregation of abnormal prion protein (PrP) in the central nervous system. Although several small compounds that bind to normal PrP (PrP) have been shown to inhibit structural conversion of the protein, an effective therapy for human prion disease remains to be established. In this study, we screened 1200 existing drugs approved by the US Food and Drug Administration (FDA) for anti-prion activity using surface plasmon resonance imaging (SPRi).

Real-Time Quaking-Induced Conversion for Diagnosis of Prion Disease.

Sporadic human prion diseases are defined on the basis of clinical features, with periodic sharp discharge (PSD) on electroencephalograms (EEG), a positive 14-3-3 protein assay of CSF samples, and abnormal signals on cerebral cortex on diffusion-weighted (DWI) MR images. It is essential to detect the abnormal prion protein in neuropathological or immunochemical detection of brain tissues when we diagnose definite cases for human prion disease. We performed definite diagnosis of sporadic human prion disease in alive patients.

Prion-Like Seeding of Misfolded α-Synuclein in the Brains of Dementia with Lewy Body Patients in RT-QUIC.

The prion-like seeding of misfolded α-synuclein (αSyn) involved in the pathogenesis of Lewy body diseases (LBD) remains poorly understood at the molecular level. Using the real-time quaking-induced conversion (RT-QUIC) seeding assay, we investigated whether brain tissues from cases of dementia with Lewy bodies (DLB), which contain serine 129 (Ser129)-phosphorylated insoluble aggregates of αSyn, can convert Escherichia coli-derived recombinant αSyn (r-αSyn) to fibrils. Diffuse neocortical DLB yielded 50% seeding dose (SD) values of 10~10/g brain.