title: Immunoreactivity to ubiquitin-protein conjugates is present early in the disease process in the brains of scrapie-infected mice.
abstract: Brains from mice infected with either the 87V or the ME7 strains of mouse-passaged sheep scrapie were taken at stages during the disease process and immunostained to show the localization of ubiquitin-protein conjugates. In both models, conjugates were seen as fine, dot-like structures; as coarser, granular lesions within or adjacent to neurones; and in areas surrounding plaques. The dot-like structures were visible at 28 days post-ME7 infection and at 55 days in 87V-infected mice. In both models, the extent of immunoreactive changes increased as the disease progressed and terminal infection was as described earlier by us (Lowe et al., J. Pathol 1990; 162: 61-66). The patterns of development of these features were distinctive in two ways: progression from region to region was observable and the density of the pathological lesions grew exponentially as the clinical symptoms appeared. The earliest pathological dot-like structures corresponded temporally with the earliest detection of PrPSC by Western blotting, and immunogold electron microscopic investigation of the dot-like lesions indicated that they were the multi-vesicular, lysosome-related, dense bodies that we have described previously in terminal disease (Laszlo et al., J Pathol 1992; 166: 333-341). Until now, ubiquitin-protein conjugates were seen mainly in inclusion bodies associated with the terminal stages of a range of human degenerative diseases. This study establishes that ubiquitin-protein conjugates accumulate in lysosome-related bodies very early and appear to be intimately related to the pathological processes in the animal disorders that we have studied.
authors.affiliation: Department of Pathology, University of Nottingham Medical School, Queen's Medical Centre, U.K.
authors.forename: J
authors.initials: J
authors.lastname: Lowe
authors.forename: J
authors.initials: J
authors.lastname: Fergusson
authors.forename: N
authors.initials: N
authors.lastname: Kenward
authors.forename: L
authors.initials: L
authors.lastname: Laszlo
authors.forename: M
authors.initials: M
authors.lastname: Landon
authors.forename: C
authors.initials: C
authors.lastname: Farquhar
authors.forename: J
authors.initials: J
authors.lastname: Brown
authors.forename: J
authors.initials: J
authors.lastname: Hope
authors.forename: R J
authors.initials: RJ
authors.lastname: Mayer
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology; D001923:Brain Chemistry; D051379:Mice; D008815:Mice, Inbred Strains; D011506:Proteins / Q000032:analysis* / Q000276:immunology; D012608:Scrapie / Q000378:metabolism* / Q000473:pathology; D014452:Ubiquitins / Q000032:analysis* / Q000276:immunology
chemical_list: D011506:Proteins; D014452:Ubiquitins