Fig. 4

Surface IR are increased on GENZ-treated mHippoE-14 cells due to decreased levels of caveolin-1. a Western blot shows that total caveolin-1 but not clathrin levels are decreased in GENZ-treated cells (100 nM insulin, 10 min, n = 4). b Cells are either treated with caveolin-1- or control siRNA. Western blot confirms that the siRNA efficiently reduces caveolin-1. Total IR levels are increased in caveolin-1 siRNA treated-cells (n = 4). c A PLA shows that treatment with either caveolin-1 siRNA or GENZ increases surface IR on non-permeabilized cells (n = 91–129 cells). d Caveolin-1 is decreased in GENZ-treated mHippoE-14 cells despite ADDL exposure (n = 4). e The number of caveolae has been evaluated by EM of vehicle- or GENZ-treated cells exposed to either saline or ADDLs. GENZ treatment decreases the number of caveolae despite ADDL exposure. The typical morphology of structures defined as caveolae is shown in the inset (arrowheads). Cells with a completely intact membrane have been chosen and the total number of caveolae per cell membrane outline has been counted (n = 10 cells). Unpaired two-tailed student’s t-test (if p ≤ 0.05, p ≤ 0.01, or p ≤ 0.001 results are marked with (*), (**) or (***), respectively); 5 μM ADDLs, 24 h. Means ± SEM. Scale bar: 5 μm