Mechanism of Neuronal versus Endothelial Cell Uptake of Alzheimer's Disease Amyloid β Protein
A–D: Uptake of fluorescein labeled Aβ40 (F-Aβ40) and Alexa Fluor® 647 labeled cholera toxin (AF647-CT), caveolae-mediated endocytosis marker, by differentiated PC12 cells following 30 min incubation. (A) F-Aβ40 uptake; (B) Uptake of AF647-CT; (C) Sparse co-localization of F-Aβ40 and AF647-CT as indicated by the white masked areas; (D) Superimposition of images A and B on the differential interference contrast (DIC) image to show the location of the fluorophores in the cells. E–G: Uptake of F-Aβ40 and AF647-CT in differentiated PC12 cells treated with filipin, which is known to inhibit caveolae mediated endocytosis. (E) Uptake of F-Aβ40; (F) Substantial reduction in AF647-CT uptake in the cells treated with filipin; (G). Superimposition of images E and F on the differential interference contrast (DIC) image to show the health of filipin treated cells.