PURPOSE: A characteristic of prion diseases which affect both animals and humans is the aggregation of PrP amyloid fibrils in the brain, associated with a chronic inflammatory response dominated by microglial activation. In this study, we hypothesised that specific ligands of the 18-kDa translocator protein (TSPO) would be effective in the evaluation of microglial activation related to PrP(sc) deposits in prion disease. PROCEDURES: Chronological studies using in vitro autoradiography were carried out with [(3)H]-PK11195 and [(125)I]-IMPY on frozen cerebral sections from scrapie-infected mice and controls. Accumulation of prion deposits was confirmed by histoblot staining with prion protein-specific monoclonal antibody. Ex vivo autoradiographic studies were carried out with [(125)I]-CLINDE and [(125)I]-IMPY at the terminal stage of infection. RESULTS: Chronological studies using in vitro autoradiography showed that PrP(sc) deposits were co-localised with activated microglia as early as 60 days post-inoculation. Progressive levels of PrP(sc) and TSPO staining were successively observed in the hippocampus, cortex and left thalamus of infected mouse brain sections in the course of the disease and were correlated with the signals obtained by histoblot staining. Significant TSPO labelling was also observed ex vivo in the cortex, hippocampus and thalamus of scrapie-infected mice. In parallel, [(125)I]-IMPY showed labelling in the same cerebral regions but with high background staining. CONCLUSIONS: These findings indicate the ability of [(125)I]-IMPY and [(125)I]-CLINDE to evaluate prion deposits and microglial activation in vitro and ex vivo in scrapie-infected mice at different stages of the disease.
PURPOSE: A characteristic of prion diseases which affect both animals and humans is the aggregation of PrP amyloid fibrils in the brain, associated with a chronic inflammatory response dominated by microglial activation. In this study, we hypothesised that specific ligands of the 18-kDa translocator protein (TSPO) would be effective in the evaluation of microglial activation related to PrP(sc) deposits in prion disease. PROCEDURES: Chronological studies using in vitro autoradiography were carried out with [(3)H]-PK11195 and [(125)I]-IMPY on frozen cerebral sections from scrapie-infectedmice and controls. Accumulation of prion deposits was confirmed by histoblot staining with prion protein-specific monoclonal antibody. Ex vivo autoradiographic studies were carried out with [(125)I]-CLINDE and [(125)I]-IMPY at the terminal stage of infection. RESULTS: Chronological studies using in vitro autoradiography showed that PrP(sc) deposits were co-localised with activated microglia as early as 60 days post-inoculation. Progressive levels of PrP(sc) and TSPO staining were successively observed in the hippocampus, cortex and left thalamus of infectedmouse brain sections in the course of the disease and were correlated with the signals obtained by histoblot staining. Significant TSPO labelling was also observed ex vivo in the cortex, hippocampus and thalamus of scrapie-infectedmice. In parallel, [(125)I]-IMPY showed labelling in the same cerebral regions but with high background staining. CONCLUSIONS: These findings indicate the ability of [(125)I]-IMPY and [(125)I]-CLINDE to evaluate prion deposits and microglial activation in vitro and ex vivo in scrapie-infectedmice at different stages of the disease.
Authors: Annachiara Cagnin; Martin Rossor; Elizabeth L Sampson; Toby Mackinnon; Richard B Banati Journal: Ann Neurol Date: 2004-12 Impact factor: 10.422
Authors: Annick Le Dur; Vincent Béringue; Olivier Andréoletti; Fabienne Reine; Thanh Lan Laï; Thierry Baron; Bjørn Bratberg; Jean-Luc Vilotte; Pierre Sarradin; Sylvie L Benestad; Hubert Laude Journal: Proc Natl Acad Sci U S A Date: 2005-10-20 Impact factor: 11.205
Authors: Déborah Tribouillard-Tanvier; Brent Race; James F Striebel; James A Carroll; Katie Phillips; Bruce Chesebro Journal: J Virol Date: 2012-07-11 Impact factor: 5.103