Involvement of the cellular prion protein in seeding and spreading of sarkosyl-derived fractions of Alzheimer's disease in Prnp mutant mice and in the P301S transgenic tauopathy mice model

The natural cellular prion protein is known to play several roles during development and adult brain. Far from its pathological roles in prionopathies, the non-pathogenic cellular prion protein has been described as a receptor for several amyloid in oligomeric and prefibrillar forms. For some amyloids, specific domains of the protein play a crucial role in modulating amyloids cellular uptake and seeding properties. In most studies, the functions and the role of putative amyloid receptors have been analyzed by using brain extracts derived from human neurodegenerative patients. Another strategy has been to modify the genetic dosage of the natural prion protein in genetic models of different diseases. In this study, we take advantage of both approaches to examine whether this protein plays a role in the seeding and spreading of pathogenic tau. Our results point to a role of the natural prion protein in the emergence of pathogenic tau in a mouse model overexpressing the mutation P301S of the human tau gene. In contrast, its role is minor when sarkosyl-derived brain samples of Alzheimers disease are used. In fact, our results indicate that the use of this type of sample is not adequate to determine the role of a putative receptor in tau seeding and spreading.