Figure 4. Perturbing the miR-30c-5p/Me1 axis affects cocaine-induced ROS elevation in mouse aortic SMCs.

SMCs were stably transduced with lentiviral vectors expressing miR-30c-5p, miR-Zip30c, or miR-Ctr. (A) miR-30c-5p expression was increased in the miR-30c-5p transduced cells and decreased in the miR-Zip30c transduced cells (*: p < 0.05 vs. miR-Ctr). (B) Cocaine dose-dependently decreased Me1 expression, an effect that was exacerbated by overexpression of miR-30c-5p. MiR-Zip30c transduction led to increased Me1 expression, which was unaltered after cocaine treatment. (C) Prostaglandin levels were elevated in miR-30c-5p transduced cells, and were further elevated by cocaine in a dose-dependent manner. MiR-Zip30c not only decreased the basal level of prostaglandin but also abrogated the effect of cocaine on increasing prostaglandin. (D-E) Overexpression of miR-30c-5p exacerbated the effect of cocaine on increasing H₂O₂ (detected by DCF staining) and nitrotyrosine levels. Conversely, silencing miR-30c-5p eliminated cocaine-induced increases in H₂O₂ and nitrotyrosine levels (*: p < 0.05 vs. respective miR-transduced SMC line alone; #: p < 0.05 vs. miR-Ctr-transduced SMCs alone).