Treatment with hemin affects miRNA expression levels.A, HEK 293 cells were treated with 10 μm hemin for 1 h followed by an 8-h incubation in basal medium. Treatment with hemin significantly reduced levels of miR-217 compared with control (p < 0.05). Levels of miR-377 were also reduced (p = 0.08) compared with control. B, primary HUVEC cells were treated with 10 μm hemin for 1 h followed by either an 8- or 24-h incubation in basal medium. Levels of miR-217 were significantly reduced after 24 h compared with control cells (p < 0.05). Levels of miR-377 were not significantly reduced compared with control cells. C, treatment with hemin followed by an 8-h incubation did not significantly alter levels of miRNA of four other miRNAs (miR-873, miR-520a-5p, miR-525–5p, and miR-1205) predicted to interact with the HMOX1–3′ UTR. Data are presented as mean ± S.E., with n = 3 trials per condition. *, p < 0.05 using a one-way ANOVA with Bonferroni t test post-test.