title: Correlative studies support lipid peroxidation is linked to PrP(res) propagation as an early primary pathogenic event in prion disease.
abstract: To assess whether heightened oxidative stress plays an early and primary pathogenic role in transmissible spongiform encephalopathies (TSE), we undertook detailed correlative studies using a mouse-adapted model of human disease. The spatio-temporal evolution of the abnormal, protease-resistant isoform of the prion protein (PrP(res)) and neuropathological changes were correlated with the occurrence and type of oxidative stress. Heightened oxidative stress was demonstrated, but restricted to elevated levels of free aldehydic breakdown products of lipid peroxidation, affecting all brain regions to varying extents. The increase in lipid peroxidation was highest over the mid-incubation period, with the onset showing close temporal and general topographical concordance with the first detection of PrP(res) with both pre-empting the typical neuropathological changes of spongiform change, gliosis and neuronal loss. Further, prion propagation over the disease course was assessed using murine bioassay. This revealed that the initial rapid increase in infectivity titres was contemporaneous with the abrupt onset and maximisation of lipid peroxidation. The present results are an important extension to previous studies, showing that heightened oxidative stress in the form of lipid peroxidation is likely to constitute an early primary pathogenic event in TSE, associated temporally with the integral disease processes of prion propagation and PrP(res) formation, and consistent with causal links between these events and subsequent typical neuropathological changes.
authors.affiliation: Department of Pathology, The University of Melbourne, Vic. 3010, Australia.
authors.forename: Marcus W
authors.initials: MW
authors.lastname: Brazier
authors.forename: Victoria
authors.initials: V
authors.lastname: Lewis
authors.forename: Giuseppe D
authors.initials: GD
authors.lastname: Ciccotosto
authors.forename: Genevieve M
authors.initials: GM
authors.lastname: Klug
authors.forename: Victoria A
authors.initials: VA
authors.lastname: Lawson
authors.forename: Roberto
authors.initials: R
authors.lastname: Cappai
authors.forename: James W
authors.initials: JW
authors.lastname: Ironside
authors.forename: Colin L
authors.initials: CL
authors.lastname: Masters
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Hill
authors.forename: Anthony R
authors.initials: AR
authors.lastname: White
authors.forename: Steven
authors.initials: S
authors.lastname: Collins
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western / Q000379:methods; D001921:Brain / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007150:Immunohistochemistry / Q000379:methods; D015227:Lipid Peroxidation / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D018620:PrPSc Proteins; D017096:Prion Diseases / Q000235:genetics / Q000503:physiopathology*; D011328:Prions / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D013997:Time Factors
chemical_list: D005904:Glial Fibrillary Acidic Protein; D018620:PrPSc Proteins; D011328:Prions; D010751:Phosphopyruvate Hydratase