Fig. 3.

Maturation of α-syn–seeded aggregates into LB-like inclusions is accompanied by the sequestration of organelles and the endomembrane system. (A–D) At D21, PFF-treated neurons were fixed, ICC against pS129-α-syn was performed and imaged by confocal microscopy (Insets) and selected neurons were examined by EM. Representative images of LB-like inclusions exhibiting a ribbon-like morphology (A and B) or compact and rounded structures (C and D). Mitochondria, autophagosomes, endosome, and lysosome-like vesicles were detected inside or at the edge of these inclusions (see also Fig. S6 A–E). (E–H) LB-like inclusions were stained by pS129 in combination with organelles markers LAMP1 (late endosomes) (E), LAMP2A (autophagosomes) (F), Tom20 (mitochondria) (G), or BiP (ER) (H). Neurons were counterstained with MAP2 antibody and nucleus with DAPI (see also Fig. S6 F–I). (Scale bars: A–D, Insets, 5 μm; E–H, 10 μm.)