Figure 3.

Protein expression and morphological characteristics of tau in iNgn2 neurons. (A) As assessed by western blots, there is robust expression of total tau (TAU5) and p-Tau (Tau-pS396) proteins in 14-day iNgn2 neurons from acutely transduced iPSC and NPC, and the iNgn2-NPC stable cell line. For comparison, human brain tissue from the anterior cingulate cortex (ACC) was also probed for tau expression. p-Tau was not detected in the ACC sample. This could be due to either enhanced tau phosphorylation in our iNgn2 neurons, or artifactual dephosphorylation that occurred during processing of the autopsied brain³⁸. Full-length blots are presented in Supplementary Fig. S11. (C) Morphologically assessed by immunofluorescence imaging, p-Tau (Tau-pS396) preferentially colocalizes with the axonal marker (SMI312) and not the dendritic marker (MAP2) in 14-day iNgn2 neurons. Scale bar represents 50 μm. (D) Immunostaining of p-Tau (PHF-1) and total tau (K9JA) in 14-day iNgn2 neurons. Scale bar represents 50 μm.