Figure 3.

MiR-137 regulated CDC42 and caspase proteins in H₂O₂ -induced cardiomyocyte apoptosis. (A) The putative binding sites of murine miR-137 on wild-type (WT) CDC42 3′-UTR was highlighted. A mutated (Mut) CDC42 3′-UTR sequence was generated for the application of luciferase assay. (B) In a dual-luciferase reporter assay, HEK293T cells were transfected with firefly luciferase reporter inserted with WT CDC42 3′-UTR (CDC42-WT), or the reporter inserted with Mut CDC42 3′-UTR (CDC42-WT). Also, cells were co-transfected with either miR-137 mimics or its negative control miRNA (miR-NC). Twenty-four hours after transfection, relative luciferase activities were evaluated and normalized to the values in cells transfected with CDC42-MU (* P<0.05). (C) Cardiomyocytes were transfected with either miR-C or miR-137-In lentiviruses for 24 h, followed by another 24 h treatment of 100 μM H₂O₂. Western blotting analysis was used to compare the protein expression levels of CDC42, caspase-3 and caspase-9.