Fig. 4

DOR is the target gene of miR-326. (a) The transfection efficiencies of PC12 cells transfected with miR-326 mimics, miR-326 inhibitor and relative controls, as represented by red fluorescence, were approximately 80–90% after transfection for 24 h. The expression levels of miRNA-326 were significantly upregulated in PC12 cells transfected with miR-326 mimics and significantly downregulated in PC12 cells transfected with miR-326 inhibitor compared with those in the relative controls (^****P < 0.001). (b) The mRNA and protein expression levels of DOR were significantly downregulated in PC12 cells transfected with miR-326 mimics (^**P < 0.01) and significantly upregulated in PC12 cells transfected with miR-326 inhibitor compared with those in the controls (^***P < 0.005). (c) Schematic representation of the predicted miR-326-binding site in the DOR 3′-UTR in both humans and rats. The luciferase activity of cells transfected with the DOR-wild-type (WT) reporter, which contained the predicted miR-326-binding site with the target sequence of the wild-type 3′-UTR, was significantly suppressed by cotransfection with miR-326 mimics (^*P < 0.05), while there was no significant difference in cells transfected with the corresponding DOR-mutated-type (MUT), which contained a putative miR-326 binding site with a mutant region in the 3′-UTR (ⁿP > 0.05)