Fig. 4.

Overexpression of hsa-miR-200b-3p exacerbates cell apoptosis induced by H₂O₂ and ox-LDL. a HUVECs were transfected with negative control (NC) mimic (50 nM) and hsa-miR-200b-3p (miR-200b) mimic (50 nM) for 24 h, then qRT-PCR for hsa-miR-200b-3p was used to access the transfection efficiency (n = 4 for each group). b HUVECs were transfected with NC mimic and miR-200b mimic for 24 h, then cells were stimulated with H₂O₂ (50 μM) or ox-LDL (100 μg/ml) for 6 h. The apoptosis of HUVECs was detected by Annexin V and PI staining. c The apoptosis ratio of HUVECs was calculated (n = 3 for each group). d The mRNA levels of anti-apoptosis gene BCL2 and pro-apoptosis gene BAX in H₂O₂ stimulated HUVECs were examined by qRT-PCR (n = 4 for each group). e The mRNA levels of BCL2 in ox-LDL stimulated HUVECs were examined by qRT-PCR (n = 4 for each group). f The protein levels of BCL2 and BAX in ox-LDL stimulated HUVECs were examined by western blot, and normalized with GAPDH. The right histogram was the ratio of BCL2 and BAX (n = 3 for each group). Full-length blots/gels are presented in Additional files 2 and 3: Figure S1 and S2. g The activity of Caspase3/7 in H₂O₂ stimulated HUVECs was examined by Caspase-Glo® 3/7 Assay System (n = 6 for each group). h HUVECs were transfect with NC mimic and miR-200 mimic for 24 h, then the proliferation rate of HUVECs was accessed by EdU staining (Bar, 50 μm, n = 6 for each group). Unpaired t test was used for comparison between groups, *p < 0.05, **p < 0.01