Fig. 4.

Relevance of Aβ uptake for plaque formation. (A) Cytochalasin B (Cyt) or latrunculin B (Lat) decrease plaque formation in THP-1 cells as shown with the filter retention assay after 1 d incubation (n = 24). The value obtained with untreated THP-1 cells was set to 100%. Medium supplements as described in Fig. 1A. (B) Lag time of in vitro Aβ(1–40) fibrillation reactions with or without Lat or Cyt, monitored with ThT fluorescence (n = 8). (C, D) Cell viability measurements with the lactate dehydrogenase assay. (C) Cyt or Lat are not toxic to THP-1 cells (1 d incubation, no Aβ addition, n = 7). (D) Plaque formation reduces THP-1 cell viability (different time points shown, n = 14). The value obtained with full cell lysis was set to 100%. Panels (A–C) use always 6 μM Cyt or 2.5 μM Lat.