FIGURE 5.

CsA causes accumulation of apoE-GFP in vesicular structures within the ER network of CHO cells. CHO cells stably expressing human apoE-GFP (green) were treated with 5 μm CsA or control vehicle DMSO for 1 h and then immunostained for ER marker (biotinylated concanavalin A (conA), followed by streptavidin-Alexa Fluor 546 conjugate, A) or stained for lysosomes (Lysotracker Red DND-99, B), Golgi marker (BODIPY-TR conjugated ceramide, C), and subjected to confocal microscopy using a ×63 oil (A) or water (B and C) immersion lens. Insets in apoE-GFP panels in A–C showed magnified view of vesicular structures seen after CsA but not DMSO control. Note the strong co-localization of apoE with ER in contrast to minimal co-localization with lysosomes or Golgi both in control and CsA-treated cells. Treatment with CsA generates larger apoE-containing structures, which are heterogeneous in size, and which are excluded from the Golgi region and retained within the ER.