Fig. 1

Establishment of seeding based cell assay for tauopathy. a Experimental scheme for the seeding based cellular assay. Brain lysate from rTg4510 mice or PFFs were added into the medium of HEK293 cells expressing Tau-PL-V5 (1:1000 dilution for brain lysate and 1:250 dilution for PFF). After 1 day incubation, cell lysate was subjected to ultracentrifugation to isolate soluble and insoluble protein pool. b Cells were transfected with Tau-PL-V5 plasmid. pCMV5 plasmid was used as control. The transfected cells were then treated with Tg or control brain lysates. Western blots show that cellular insoluble tau could only be induced in cells expressing Tau-PL-V5 and treated with Tg brain lysate, but not in other groups. c Cells were transfected with Tau-PL-V5 plasmid. pCMV5 plasmid was used as control. Transfected cells were treated with equal amount of the brain lysates from 1, 4 and 7 month old Tg mice. Western blots show that seeding activity of brain lysate increased in an age dependent manner. d Cells were transfected with Tau-PL-V5 plasmid. pCMV5 plasmid was used as control. The transfected cells were treated with PFF or PBS. Western blots show that PFFs also could be used as seeds to trigger insoluble tau in seeding based cellular assay. e Cells were transfected with Tau-PL-V5 plasmid. The transfected cells were treated with control, 4 month rTg4510 or 9 month PS19 brain lysates. Western blots show that only rTg4510 brain lysate could trigger insoluble tau in seeding based cellular assay