tailieunhanh - Báo cáo khoa học: Prions and prion diseases

1The epidemic of bovine spongiform encephalopathy (BSE), or ‘mad cow disease’, and the subsequent emer-gence of a new variant of Creutzfeldt–Jakob disease (vCJD) in humans, has directed great political and sci-entific attention to a family of related neurodegenera-tive protein-misfolding diseases, collectively known as transmissible spongiform encephalopathies (TSEs) or prion diseases. | IFEBS Journal MINIREVIEW SERIES Prions and prion diseases Michael Beekes Robert Koch-Institut P24 - Transmissible Spongiforme Enzephalopathien Berlin Germany The epidemic of bovine spongiform encephalopathy BSE or mad cow disease and the subsequent emergence of a new variant of Creutzfeldt-Jakob disease vCJD in humans has directed great political and scientific attention to a family of related neurodegenera-tive protein-misfolding diseases collectively known as transmissible spongiform encephalopathies TSEs or prion diseases. TSEs cause a progressive and eventually fatal degeneration of the central nervous system CNS . All members of this group of diseases are characterized by the deposition in the CNS of a pathological form of the prion protein PrP with an aberrant folding and or aggregation structure PrPTSE . The puzzling properties of scrapie- and other TSE agents have caused a vivid controversial debate about the molecular nature and biochemical composition of these pathogens for many years. According to the prion hypothesis the causative agents of TSEs are proteinaceous infectious particles prions which are composed essentially - if not entirely - of misfolded prion protein referred to as PrPSc. The formation and amplification of infectious PrPSc is assumed to follow a mechanism of seeded aggregation but for a long time it could not be shown that misfolded proteinase K-resistant prion protein PrPres generated ex vivo is associated with pathogenic infectivity . the ability to induce a TSE in vivo . However substantial advances on the in vitro generation of infectious scrapie prions by growing amyloid fibrils from bacterially expressed recombinant PrP or by replicating PrPres using protein misfolding cyclic amplification PMCA have been achieved recently. As reviewed by Ilia Baskakov this added new pieces of evidence to the puzzle of findings corroborating the prion hypothesis. Prions underlie the transmission of TSEs in the animal kingdom between humans and .