In vitro generation of tau aggregates conformationally distinct from parent tau seeds of Alzheimer's brain.

Normal monomeric tau can be converted into pathogenic aggregates and acquire protease resistance in a prion-like manner. This acquisition of partial protease-resistance in tau aggregates has to date only been partially investigated in various studies exploring the prion-like properties of tau. In this study, we induced the aggregation of tau repeat domain (RD) in cultured cells using detergent insoluble fractions of Alzheimer's brain tissue as seeds. The seeded aggregation of tau RD in cultured cells formed a ~7 kDa protease-resistant fragment in contrast to the ~12 kDa tau fragment characteristic of the AD seeds, suggesting that the in vitro generated tau aggregates were conformationally distinct from parent seeds.