Figure 3. (A–D) MiR-107 targeted BACE1. CVB3 was infected with Hela cells after the transfection with miRNA mimics or inhibitors. Cellular proteins were used for western blot analysis. RT-qPCR was performed to determine the mRNA level of BACE1. (E). Luciferase was adopted to validate downstream BACE1 of miR-107, and Hela cells were co-transfected with BACE1-wt/mut and miR-107 or miR-CL. The activity of firefly and leucinase was calculated by the ratio of double luciferase to leucinase. (F) BACE1 knockdown promoted the phosphorylation of NFκB. Hela cells that were transfected with si-BACE1 were infected with CVB3 virus afterward. Cellular protein expressions of NFκB and p-NFκB were detected by western blot. (G) The overexpression of BACE1 partially reversed the facilitating effect of miR-107 on the production of VP-1 and the phosphorylation of NFκB. The activity of NFκB signaling was detected using western blot. (H) Viral titers were determined by plaque assay. (I) The replication level of EGFP-Iabeled CVB3 was observed in Hela cells which had been transfected with siBACE1 or pcDNA-BACE1 (magnification, 4×).