Fig. 4. Cdc42 enhances the cellular uptake of EVs.

(A) Western blot analysis of the level of Cdc42 in cells expressing Cdc42^Q61L. (B) Confocal images of reporter⁺ cells expressing Cdc42. In the Cre-LoxP reporter system (see Fig. 1A), Cre⁺ cells were cocultured with reporter⁺ cells for 48 hours after the transfection of Cdc42^Q61L plasmid. Scale bars, 100 μm. (C) Western blot analysis of the level of Cdc42 in reporter⁺ cells, which were treated with 0, 50, or 100 nM Cdc42 small interfering RNA (siRNA) for 48 hours. (D) Confocal microscopy images of reporter⁺ cells. Both Cre⁺ cells and reporter⁺ cells were treated with 100 nM Cdc42 siRNA. After 6 hours, the medium was replaced with fresh medium. Then, Cre⁺ cells were treated with 0.5 μM ODN or 20 μM GW4869 for 24 hours before being mixed with reporter⁺ cells. After 24 hours, cells were observed by confocal microscopy. Scale bars, 50 μm. Graphs in (B) and (D) represent the percentage of reporter⁺ cells with GFP signals and show means ± SEM. [**P < 0.01 using unpaired Student’s t test (B); *P < 0.05 using ANOVA one-way test (D)]. The percentage of cells with GFP signals was calculated in three different fields of each condition. Images are representative of at least three independent experiments.