Journal: bioRxiv

Article Title: Pathological TDP-43 filaments accumulate at synapses and cause synaptic dysfunction

doi: 10.64898/2026.01.27.701787

Figure Lengend Snippet: A. Immunoblot of synaptosome isolation fractions (s, supernatant; cp, cell pellet; cyt, cytosolic; syn, synaptosomes) from mouse primary cortical neurons incubated with (+ filaments) and without (- filaments) FTLD-TDP Type A patient brain-derived TDP-43 filaments for 3 d, probed with antibodies against postsynaptic density protein 95 (PSD95, top), pS409/410 TDP-43 (pTDP-43, middle) and TDP-43 (bottom). The arrows indicate full-length (FL) TDP-43 and C-terminal fragments (CTFs) of TDP-43. B. Denoised tomographic slices of synaptosomes from mouse primary cortical neurons incubated with FTLD-TDP Type A patient brain-derived TDP-43 filaments for 3 d. TDP-43 filaments (magenta arrows), example synaptic vesicles (cyan arrows) and the postsynaptic density (yellow arrow) are indicated. C and D. Denoised tomographic slices showing TDP-43 filaments (magenta arrows). making contacts (green arrows) with synaptic vesicles (cyan arrows) (C) and the presynaptic plasma membrane (yellow arrows) (D) . B-D. Scale bars, 50 nm.

Article Snippet: The following primary antibodies were used: Anti-phospho-serine 409 and 410 TDP-43 (Cosmo-Bio, TIP-PTD-M01; 1:1,000); anti-mouse TDP-43 residues S379-S387 (in-house, 1:400); anti-class III β-tubulin (Biolegend, 801202; 1:200); anti-class III β-tubulin (Abcam, ab6046, 1:200); anti-bassoon (Merk, ABN255; 1:250); anti-postsynaptic density protein 95 (NeuroMab, 75028; 1:1,000); anti-microtubule-associated protein 2 (Abcam, ab5392; 1:500); anti-neuronal nuclei (Abcam, EPR12763; 1:200); anti-early endosome antigen 1 (BD Biosciences, 610457; 1:200); anti-clathrin (Abcam, ab21647; 1:200), anti-hook microtubule tethering protein 3 (Sigma-Aldrich, SAB1401891; 1:100); anti-chaperonin-containing T-complex subunit 5 (Proteintech, 11603-1-AP; 1:100); anti-DnaJ homolog subfamily A member 2 (Proteintech, 12236-1-AP; 1:200); anti-14-3-3 (Origene, TA327381; 1:100); anti-microtubule associated protein 1 light chain 3B (Cosmo-bio, CACCTB-LC3-2-IC; 1:50); and anti-proteasome 20S subunit β4 PSMB4 (ThermoFisher, A303-819A; 1:50).

Techniques: Western Blot, Isolation, Incubation, Derivative Assay, Clinical Proteomics, Membrane