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® 633 labeled transferrin (AF633-Trf), clathrin-mediated endocytosis marker, by differentiated PC12 cells following 30 min incubation. (A) F-Aβ40 uptake; (B) Uptake of AF633-Trf; (C) Superimposition of images A and B; (D) Sparse co-localization of F-Aβ40 and AF633-Trf as indicated by the white masked areas. E–G: Uptake of F-Aβ40 and AF633-Trf in differentiated PC12 cells subjected conditions that inhibit clathrin mediated endocytosis (hypotonic shock for 5 min followed by incubation with potassium free salt solution for 30 min). (E) Uptake of F-Aβ40; (F) Substantial reduction in AF633-Trf; (G). Superimposition of images E and F on the differential interference contrast (DIC) image to show the condition of the cells.