Figure 5. Cigarette smoke (CS) induces exosomal miR-221-3p through binding with hnRNPA1. (A–D) CS-epithelial cells were co-transfected with wild-type or mutant miR-221-3p and hnRNPA1 and then subjected to luciferase reporter assays. The ratio of Renilla luciferase signals to firefly luciferase signals was used to normalize the luciferase activity at 48 h post-transfection. (E, F) The co-location of CD63, hnRNPA1 and miR-221-3p using immunofluorescence.