Fig. 4

RBC-EVs facilitate α-syn aggregation in the processes of astrocytes. a Representative images of brain slices (cortex) following chronic peripheral injection of RBC-EVs derived from healthy control or PD subjects, co-labeled for oligomeric α-syn, GFAP (marker for astrocytes), and Kir4.1 (marker for astrocytic endfeet). Note the increased number of α-syn aggregations overlapping with Kir4.1 in brain slice from A53T mice injected PD RBC-EV (Scale bar, 10 μm). b Quantification analysis of oligomeric α-syn/ Kir4.1 co-localization (n ≥ 5 independent animals were used in each group means + S.E.M; *p < 0.05 by One-way ANOVA test). c Representative images of human postmortem tissues (cortex) co-labeled for oligomeric α-syn, GFAP, and Kir4.1. White arrow heads indicate GFAP-labeled astrocytic process without co-localization with oligomeric α-syn, while white arrows indicate GFAP-labeled or Kir4.1-labeled astrocytic process showing co-localization with oligomeric α-syn (Scale bar, 10 μm). d-e Quantification analysis of oligomeric α-syn/GFAP co-localization (d) and α-syn/ Kir4.1 co-localization (e) at cortex (CTX), striatum (STR), substantia nigra (SN) and cerebellum (CERE) (means + S.E.M; n = 5; **p < 0.01 by One-way ANOVA test)