The IL-16 3'-UTR is the specific target of miR-81. (A) Binding sites of miR-81 were present in the 3'-UTR of IL-16. TargetScan was used to identify the target sites. (B) Construction profile of the psiCHECK IL-16 plasmid. The binding sequence in the IL-16 3'-UTR was replaced in the psiCHECK-IL-16 MUT plasmid. (C) The relative luciferase activity of psiCHECK-IL-16 was reduced by miR-81. We transfected PC12 cells with the psiCHECK-2-IL-16 vector (200 ng), miR-81 mimic (100 nM), or miR-81 mimic-NC (100 nM) for 48 h using Lipofectamine 2000. *P<0.05 vs.
miR-81 NC + psiCHECK-IL-16 group. Data were presented as the mean ± standard error of the mean. Untransfected cells were used as the sham group. (D) The expression of IL-16 mRNA was reduced by miR-81 in PC12 cells. We transfected PC12 cells with miR-81 mimic (100 nM), miR-81 mimic-NC (100 nM), miR-81 inhibitor, and miR-81 inhibitor-NC for 48 h using Lipofectamine 2000. ****P<0.0001. Data were presented as the mean ± standard error of the mean. (E) The expression of IL-16 mRNA was reduced in PC12 cells due to miR-81. **P<0.01 vs. mimic-NC, ##P<0.01 vs. inhibitor-NC. IL-16, interleukin-16; UTR, untranslated region; miR, microRNA; NC, negative control; WT, wild type; MUT, mutant; mRNA, messenger RNA.