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, in rat primary hippocampal (RPH) neurons following 30 min incubation at 37°C. (A) F-Aβ40 uptake; (B) Uptake of AF633-Trf; (C) Superimposition of images A and B; (D) Overlay of fluorescence images on the DIC image of RPH neurons. E–G: Uptake of F-Aβ40 and AF633-Trf in RPH neurons at 4°C. (E) Uptake of F-Aβ40; (F) No significant neuronal uptake of AF633-Trf at 4°C; (G) Superimposition of images D and E on the DIC image of RPH neurons; H–J: Uptake of F-Aβ40 and AF633-Trf in RPH neurons treated with 10 mM Sodium Azide and 50 mM 2-deoxy glucose, agents that are known to deplete cellular ATP. (H) Uptake of F-Aβ40; (I) No significant cellular uptake of AF633-Trf was observed; (J) Superimposition of images H and I on the DIC image of neurons.