Fig. 5

PIK3R3 was a target gene for miR-331-3p. A The putative miR-331-3p-binding sites and their mutations were shown in PIK3R3 3’UTR. B Luciferase activity of reporter vector was measured by dual-luciferase reporter assay, and relative luciferase activity of WT-PIK3R3 3’UTR and MUT-PIK3R3 3’UTR was determined in HAC cells co-transfected with miR-NC or miR-331-3p mimic. C RNA expression was analyzed by RT-qPCR, and relative miR-331-3p expression was determined in anti-miR-NC or anti-miR-331-3p-transfected HAC cells. D–G PIK3R3 protein and mRNA expression were respectively detected by western blotting and RT-qPCR, and its relative expression was determined in (D) HAC cells transfected with miR-NC, miR-331-3p, anti-miR-NC, or anti-miR-331-3p, and E OA cartilages (n = 20) and normal cartilages (n = 20), F OA cartilages (O1, O2 and O3) and normal cartilages (N1, N2 and N3), and G OA chondrocytes and normal chondrocytes from patients. H The correlation coefficient (r) between miR-331-3p and PIK3R3 mRNA in OA cartilages (n = 20) was determined using Pearson correlation test. *P < 0.05