FIGURE 1.

Minor contribution of endogenous secreted PCSK9 to LDLR intracellular degradation. a, HepG2 cells were incubated for 4 h with 0.3% v/v of dimethyl sulfoxide (DMSO) (vehicle) or 80 μm Dynasore monohydrate, a cell-permeable inhibitor of dynamin together with 4 μg/ml diI-LDL (red) and analyzed by immunocytochemistry. b, after a 6-h incubation with dimethyl sulfoxide or 80 μm Dynasore, protein extracts were analyzed by Western blotting. c, immunocytochemistry of nonpermeabilized HepG2 cells that were transfected with either a nonsilencing siRNA (siCtl) or an ARH siRNA at 72 h after transfection is shown. Arrows emphasize the increased cell surface LDLR. (d) At 72 h after transfection, protein extracts were analyzed by Western blotting. These data are representative of three to six separate experiments. Scale bars, 20 μm.