a Efficiency of Rab5a siRNA and WT Rab5a plasmid transfection in HPMECs. HPMECs were cultured on coverslips and transfected with either Cy3-tagged Rab5a siRNA for 12 h using the X-tremeGENE siRNA Transfection Reagent or the GFP-tagged WT Rab5a plasmid for 48 h using the X-tremeGENE HP DNA Transfection Reagent. The localization of Rab5a siRNA and Rab5a WT in HPMECs was detected using CLSM. Similar results were obtained in three separate experiments. Blue, DNA staining with DAPI (nuclear); red, Cy3; green, GFP. Scale bar 25 µm. b Rab5a expression in HPMECs after transfection with Rab5a siRNA was assayed. HPMECs were transfected with NC siRNA (control siRNA), Rab5a siRNA, NC plasmid (empty plasmid), or the Rab5a–GFP WT plasmid. Representative bands showing Rab5a (upper panel) and GAPDH expression (lower panel) are shown. A histogram illustrates the quantitative analysis of the protein levels of endogenous Rab5a, normalized to GAPDH expression. The data are presented as the mean ± SE. n = 3. *p < 0.05 versus the control and NC siRNA groups