Figure 3.

The effect of melatonin on miR-132 and miR-34 expression in cholangiocytes under conditions of oxidative stress. (A) Oxidative stress induced either by H₂O₂ or tert-Butylhydroquinone (tBHQ) enhanced the expression of miR-132 in H69 cells, whereas in H69miR-506 cells this response was only observed when the cells were treated simultaneously with tBHQ and melatonin. (B) The basal level of miR-132 expression was significantly increased in H69miR-506 cells in comparison to H69 cells. (C) H₂O₂ induced miR-34 expression in both H69 and H69miR-506 cells. Melatonin suppressed this enhancement, but only in H69miR-506 cells. (D) The baseline expression of miR-34 was comparable in H69miR-506 and H69 cells. Each experiment was repeated four times with similar results. MicroRNA were analyzed using real-time PCR, and the results were normalized to miR-191. Values are shown as mean ± SE.