Journal: bioRxiv

Article Title: Repurposed COMT Inhibitors Tolcapone and Entacapone Selectively Suppress Aggregation and Seeding of P301 Mutant TAU in Human Neuronal Models

doi: 10.64898/2026.04.20.719548

Figure Lengend Snippet: ( A ) Schematic of the experimental timeline showing NGN2-driven neuronal differentiation of hiPSCs and subsequent sK18f seeding phase (weeks 4–7). Representative phase-contrast images show the morphology of iPSCs, week-4 induced neurons, and week-7 mature neurons. Scale bar, 50 μm. ( B ) Alexa Fluor 647–labeled sK18 fibrils (sK18f-647) or Alexa Fluor 647 control dye were delivered into week-4 hiPSC-iNs using Xfect transfection. Images were acquired 24 h after transfection. The 647-fluorescence channel and merged 647/phase images are shown. Cyan arrowheads indicate 647-positive puncta within the dashed yellow box, with the corresponding high-magnification view displayed on the right. Scale bar, 50 μm. ( C ) hiPSC(P301L)-iNs were fixed at week 7 and immunostained for TUJ1, ProteoStat, pTAU(S202/T205), and DAPI. Full-field images of control and sK18f-treated cultures are shown. Dashed boxes indicate regions presented at higher magnification on the right, displaying individual channels for ProteoStat, pTAU(S202/T205), and DAPI. White arrows mark cells containing ProteoStat-positive puncta. Scale bar, 50 μm.

Article Snippet: Neuronal transfection was performed using Xfect (Takara, #631318) according to the manufacturer’s instructions.

Techniques: Labeling, Control, Transfection, Fluorescence