NR AWDL
AU Colombo,L.; Manzoni,C.; Gobbi,M.; De Luigi,A.; Ceci,P.; Tagliavini,F.; Forloni,G.; Salmona,M.
TI Evaluation of the neurotoxic properties of stabilized PrP82-146 oligomers
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Poster sessions PA-09
PT Konferenz-Poster
AB Recent studies suggest that the neurotoxic effects of amyloidogenic proteins are not caused by mature fibrils but by small, soluble oligomeric assemblies. The characterisation of these species would require their isolation, as well as the evaluation of their stability. The first requirement is partly overcome by testing a mixture of few, possibly well defined, peptide families (as for example, for the quite heterogeneous A oligomers called A Derived Diffusible Ligands). Very few data are available on the neurotoxic properties of PrP oligomers. To this aim, we have used PrP82-146, an amyloidogenic prion peptide found in the brains of patients with Gerstmann-Sträussler-Scheinker disease (GSS), a familial prion disease. This peptide has been syntetized and used as an in vitro tool to investigate the physico-chemical features of PrP amyloid. Photo-induced cross-linking of unmodified protein (PICUP) technique was applied to PrP82-146 solutions to covalently stabilize metastable oligomers. SDS-PAGE analysis showed that, depending on the irradiation time, solutions contained small oligomers only (1-3mers), small and medium oligomers (1-6 mers) or mostly heavy oligomers (> 13mers). Electron microscopy analyses of these preparations showed that different oligomerization profiles are associated to different morphologies containing circular and spherical structures, and aggregates made up by spheres linked together in a rosary-like array.Oligomers preparations were separated by HPLC and their toxicity tested on N2a murine neuroblastoma cells. An inverse correlation between the size of oligomers and neurotoxicity was observed, suggesting that small oligomers are the toxic entities.
AD L. Colombo, C. Manzoni, M. Gobbi, A. De Luigi, P. Ceci, GT. Forloni, M. Salmona: Istituto di Ricerche Farmacologiche Mario Negri, Milano, Italy; F. Tagliavini: Istituto Nazionale Neurologico Carlo Besta, Milano, Italy. E-mail: lcolombo@marionegri.it
SP englisch
PO Italien