High-density lipoprotein endocytosis in endothelial cells

Figure 2 Ultrastructural analysis of high density lipoprotein uptake in human umbilical vein endothelial cells. Cells incubated with HRP-labeled HDL for 30 min (A-D) or untreated controls (E, F) were processed for electron microscopy. HRP-positive clathrin-coated vesicles were seen near the cell surface (arrow in B), in tubular endosomes (asterisk in D), and densely packed MVBs were found in the perinuclear area (arrow heads in A and C). No specific staining was seen in control samples (E, F). HRP: Horseradish peroxidase; HDL: High density lipoprotein; M: Mitochondria.