As interaction of cellular prion protein (PrPc) and the infectious agent (PrPres) appears to be a crucial pathogenic step promoted by homology, variation in PrPc isoforms on bovine immune cells may explain the absence of infectivity in most bovine lymph organs. In this study, we examined PrPc expression in bovine lymph organs (tonsils and lymph nodes) and on isolated follicular dendritic cells (FDCs). We used a panel of different monoclonal antibodies (MoAbs) raised against different epitopes of prion protein. Two MoAbs recognise amino acids 79-92 (SAF 34 and SAF 32 Mo-Abs); the 6H4 antibody reacts with a specific peptide comprising the 144-152 amino acids, and the 12F10 MoAb recognises the sequence 142-160. After immunolabelling of frozen sections of lymph organs with 6H4 or 12F10 MoAbs, we detected cellular prion protein in germinal centres. However, using the SAF 34 or SAF 32 antibodies, PrPc was revealed outside the lymphoid tissues. No PrPc was observed in the germinal centres. Therefore, we adapted the method of FDC isolation, making it suitable for the study of PrPc expression on their surface. Using electron microscopy, the presence of PrPc on the surface of FDCs was demonstrated only with 6H4 MoAb. These results suggest that bovine follicular dendritic cells express a particular form of prion protein. Either the N-terminal part of PrPc is cleaved or the accessibility of the specific epitope (79-92) of SAF 34 MoAb is abolished by interaction with other molecules. This particular isoform of PrPc on bovine FDCs might be related to the apparent absence of infectivity in lymph organs in cattle affected by bovine spongiform encephalopathy.
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http://dx.doi.org/10.1007/s004410100436 | DOI Listing |
Decades after their initial observation in prion-infected brain tissues, the identities of virus-like dense particles, varicose tubules, and oval bodies containing parallel bands and fibrils have remained elusive. Our recent work revealed that a phenotype of dilation of the endoplasmic reticulum (ER), most notable for the perinuclear space (PNS), contributes to spongiform degeneration. To assess the significance of this phenotype for the etiology of prion diseases, we explored whether it can be functionally linked to other neuropathological hallmarks observed in these diseases, as this would indicate it to be a central event.
View Article and Find Full Text PDFACS Chem Neurosci
January 2025
School of Health & Life Sciences, Teesside University, Middlesbrough TS1 3BX, United Kingdom.
The aggregation of α-synuclein is crucial to the development of Lewy body diseases, including Parkinson's disease and dementia with Lewy bodies. The aggregation pathway of α-synuclein typically involves a defined sequence of nucleation, elongation, and secondary nucleation, exhibiting prion-like spreading. This study employed Raman spectroscopy and machine learning analysis, alongside complementary techniques, to characterize the biomolecular changes during the fibrillation of purified recombinant wild-type α-synuclein protein.
View Article and Find Full Text PDFNeurobiol Dis
January 2025
Office of the Saskatchewan Multiple Sclerosis Clinical Research Chair, University of Saskatchewan, Saskatoon, SK S7K 0M7, Canada; Neurology Division, Department of Medicine, University of Saskatchewan, Saskatoon, SK S7N 0X8, Canada. Electronic address:
RNA binding protein dysfunction is a pathogenic feature of multiple neurological diseases, including multiple sclerosis (MS). Neurodegeneration (the loss of, or damage to neurons and axons) is the primary driver of disease progression in MS. Herein, we utilized a novel, neuron-specific model of neurodegeneration by transducing primary mouse neurons with mutant forms of the RNA binding protein heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) identified from MS patients, including one within the M9-nuclear localization sequence of hnRNP A1 (A1(P275S)) and a second in the prion-like domain of hnRNP A1 (A1(F263S)) to test the hypothesis that neuronal hnRNP A1 dysfunction drives neurodegeneration in MS.
View Article and Find Full Text PDFJ Neurochem
January 2025
Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Canada.
Highly abundant in neurons, the cellular prion protein (PrP) is an obligatory precursor to the disease-associated misfolded isoform denoted PrP that accumulates in the rare neurodegenerative disorders referred to either as transmissible spongiform encephalopathies (TSEs) or as prion diseases. The ability of PrP to serve as a substrate for this template-mediated conversion process depends on several criteria but importantly includes the presence or absence of certain endoproteolytic events performed at the cell surface or in acidic endolysosomal compartments. The major endoproteolytic events affecting PrP are referred to as α- and β-cleavages, and in this review we outline the sites within PrP at which the cleavages occur, the mechanisms potentially responsible and their relevance to pathology.
View Article and Find Full Text PDFJ Cachexia Sarcopenia Muscle
February 2025
Department of Bioactive Material Sciences, Research Center of Bioactive Materials, Jeonbuk National University, Jeonju, Republic of Korea.
Background: The cellular prion protein (PrP), a glycoprotein encoded by the PRNP gene, is known to modulate muscle mass and exercise capacity. However, the role of PrP in the maintenance and regeneration of skeletal muscle during ageing remains unclear.
Methods: This study investigated the change in PrP expression during muscle formation using C2C12 cells and evaluated muscle function in Prnp wild-type (WT) and knock-out (KO) mice at different ages (1, 9 and 15 months).
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