Figure 5. Delivery of miR-503-5p to HCAECs and HCASMCs by macrophage-derived EVs. (A) Structure and diameter of EVs observed by TEM (×100000). (B) Diameter and number of EVs measured by NTA. (C) Expression of EV marker proteins Alix, CD63, and CD9 determined by Western blot analysis; *p < 0.05 compared with EVs. HCAECs and HCASMCs were co-cultured with EVs derived from RAW264.7 cells with or without ox-LDL treatment. (D) Expression of miR-503-5p (normalized to U6), TGF-β1, smad7, smurf1, and smurf2 (all normalized to GAPDH) in HCAECs and HCASMCs determined RT-qPCR; *p < 0.05 compared with EVs derived from RAW264.7 cells without ox-LDL treatment. (E) EVs were phagocytosed by HCAECs and HCASMCs, observed under laser confocal microscope. PKH67-labeled EVs was green, DAPI-stained nuclei was blue, while cy3-miR-503-5p-labeled EVs was red (×400). (F) Protein expression of TGF-β1, smad7, smurf1, and smurf2 (normalized to GAPDH) in HCAECs determined by Western blot analysis. Values obtained from three independent experiments in triplicate were analyzed by unpaired t test between two groups and by one-way ANOVA followed by Tukey's post hoc test among three or more groups. *p < 0.05 compared with miR-inhibitor NC-treated HCAECs co-cultured with EVs in the absence of ox-LDL; # p < 0.05 compared with miR-503-5p inhibitor treated HCAECs co-cultured with EVs in the absence of ox-LDL.