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Prions
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
Scrapie may be the oldest prion disease. The infectious nature of the disease in sheep was postulated as early as the eighteenth century, although its transmissibility was not experimentally proven until 1936 [30]. Scrapie has been reported worldwide and affects most sheep-producing regions except for Australia and New Zealand. However, recent studies have shown that scrapie has two distinct forms, classical and atypical [31]. Cases of atypical scrapie have been reported in Australia and New Zealand [32], where classical scrapie is not found. Similarly, BSE comprises classical BSE (C-type BSE), and two atypical types of the disease, named the H- and L-types [33,34]. In CWD, there are at least two strains including CWD1 and CWD2 [35], while a recent study has shown the presence of more CWD strains [36]. CWD is found in both free and captive populations and has been observed in at least 22 states in the United States and three Canadian provinces [37]. The Republic of Korea recorded CWD in imported elk [38], while CWD-reindeer was found in wild populations of Norway [39].
P
Published in Anton Sebastian, A Dictionary of the History of Medicine, 2018
Prion Disease (Syn: spongiform encephalopathy) Disorders of protein conformation that produce neurodegeneration in humans and animals. Scrapie has been known in sheep for over 200 years. Creutzfeld-Jakob disease was described by Hans Gerhard Creutzfeld (1885–1964) in 1920 and Alfons Maria Jakob (1884–1931) in 1921. Kuru was first observed by an American virologist, Daniel Carleton Gajdusek (b 1923) and V. Zigas in 1957. Kuru, scrapie and Creutzfeld-Jakob disease were recognized to be infectious in the 1960s. Spongiform bovine encephalopathy of cattle (BSE) was recognized in England in 1986 and is the result of feeding cattle with meat and bonemeal from sheep infected with scrapie. Such feeding of ruminant-derived proteins to ruminants was banned in England in 1988. After a peak in the BSE epidemic in 1993 the incidence has fallen, consistent with an incubation period of 5 years. Other diseases in the group, such as Gerstmann-Straussler-Scheinker syndrome and fatal familial insomnia were described between 1990–1995.
Dementia Associated with Medical Conditions
Published in Marc E. Agronin, Alzheimer's Disease and Other Dementias, 2014
The most widely known is Creutzfeldt–Jakob disease (CJD). Scrapie is the classic animal prion disease and is seen in sheep and goats; it spurred much of the initial research. Other mammalian prion diseases include chronic wasting disease (CWD), found in deer and elk; transmissible mink encephalopathy, found in mink; and bovine spongiform encephalopathy (BSE), found in cattle, also known as “mad cow disease.” BSE was seen widely among the cattle population in the United Kingdom in the late 1980s and early 1990s, leading to massive culling.
Ultrasensitive techniques and protein misfolding amplification assays for biomarker-guided reconceptualization of Alzheimer’s and other neurodegenerative diseases
Published in Expert Review of Neurotherapeutics, 2021
Nicole Campese, Maria Francesca Beatino, Claudia Del Gamba, Elisabetta Belli, Linda Giampietri, Eleonora Del Prete, Alessandro Galgani, Andrea Vergallo, Gabriele Siciliano, Roberto Ceravolo, Harald Hampel, Filippo Baldacci
Prions are ‘small proteinaceous infectious particles, which are resistant to inactivation by most procedures that modify nucleic acids’ according to Stanley Prusiner’s definition [27]. First described in the late sixties by Alper and Griffith in their main biochemical and biological features and recognized as the pathogenic agents of scrapie [28–30], prions consist of PrPsc, pathological aggregates of the misfolded Cellular Prion Protein (PrPc) [31]. PrPc may undergo misfolding and aberrant aggregation processes, under still not completely clarified pathophysiological mechanisms, leading to the formation of β-sheet-rich oligomers. These may subsequently promote PrPc misfolding and aggregation into highly ordered protofibrils and fibrils [31]. Protofibrils and fibrils may decay into smaller fragments acting as nucleating agents, inducing further spreading of the aberrant proteins based on sequential nucleation–fragmentation cycles [31].
Membrane insertion and intercellular transfer of glycosylphosphatidylinositol-anchored proteins: potential therapeutic applications
Published in Archives of Physiology and Biochemistry, 2020
However, the conclusion that GPI anchoring of the prion protein favours misfolding of the cellular form into the disease-linked scrapie form as well as the propagation and infectivity of prions seems to be in conflict with recent findings that prion proteins lacking the GPI anchor lead to increased production and spreading of prions in vivo and to a higher risk for the transmission of prion diseases. Compatible with these observations are the thermodynamic characterization and kinetic analysis of the conversion into amyloid fibrils of carboxy-terminally truncated anchor-less forms of prion protein (Kovač et al. 2016). Remarkably, the shortest anchor-less form turned out to be the most labile one in course of temperature increase and to be converted into amyloid fibrils most rapidly upon exposure to acidic pH compared to longer anchor-less forms or full-length GPI-anchored prion protein. Moreover, a difference in length as small as a single amino acid only was reflected in an altered lag time of fibrillization and stability vs. low pH (Kovač et al. 2016). Further detailed experimentation will be required to clarify the contribution of the GPI anchor for the replication and propagation of the scrapie form of prion protein.
The cellular prion protein and its derived fragments in human prion diseases and their role as potential biomarkers
Published in Expert Review of Molecular Diagnostics, 2019
Katrin Thüne, Matthias Schmitz, Anna Villar-Piqué, Hermann Clemens Altmeppen, Markus Schlomm, Saima Zafar, Markus Glatzel, Franc Llorens, Inga Zerr
Prion diseases, also known as transmissible spongiform encephalopathies, are a group of rapidly progressive, currently incurable, and fatal neurodegenerative diseases present in humans and animals. Key neuropathological findings shared by prion diseases and other forms of neurodegenerative conditions, such as Alzheimer`s or Parkinson`s disease, are protein aggregation, widespread neuronal loss, and neuroinflammation [1–3]. The main causative pathogenic event in prion diseases is attributed to changes in the structural conformation of the cellular prion protein (PrPC), resulting in the formation of its pathological isoform PrP Scrapie (PrPSc) in a self-propagating manner [3,4]. The molecular mechanisms that underlie this conversion of PrPC into PrPSc and the evolution of prion diseases remain elusive. Due to the rapidly progressing disease following rather long clinically silent incubation times, the high clinicopathological heterogeneity, and the lack of differentiating markers, early and reliable diagnosis of prion diseases faces significant challenges [5,6]. There is a critical need for the investigation of early pathological alterations that can help to identify early diagnostic markers and to develop novel therapeutic strategies.