SERPINE1 mRNA level in fibroblasts under hypoxia. Transfection of miRNA-449a/b inhibitors and miRNA-449a/b mimics targeted SERPINE1 mRNA under hypoxic culture conditions. The mimicking of miRNA-449a/b reversed SERPINE1 mRNA to baseline level. Depicted are calculations relative to reference gene POLR2A compared with non-transfected cells cultured under hypoxia. Negative control means cells transfected with negative control siRNA only. SERPINE1 mRNA induction through hypoxia alone and without additional transfection of miRNA-449 inhibitors or miRNA-449 mimics is indicated by the dotted line (cell line F-18). ** = p < 0.01 (three independent experiments).