Fig. 1

CVB3 infection activates P38 MAPK pathway and upregulates miRNA-21 expression, which targets the 3′UTR of MAP2K3. HELA cells were infected with CVB3 at MOI = 10 and profiling of cellular miRNA-21 and P38 MAPK proteins expression were detected, function of miRNA-21 in targeting MAP2K3 were also validated. a miRNA-21 expression was detected by Real-time PCR in CVB3-infected HeLa cell at indicated time post infection, MOI = 10. All data were normalized to U6 RNA. b Time courses for CVB3 stimulation and phosphorylation of MAP2K3 and proteins in the P38 pathways in HeLa cells. GAPDH is shown as a loading control. Shown were representative results of 3 independent tests. c Sequence alignment of miRNA-21 with putative binding sites within the wild-type and mutant 3′-untranslated regions of MAP2K3. d Relative luciferase activity of HeLa cells transfected with wild-type or mutant MAP2K3 3′UTR luciferase reporter with miRNA-21 or a mutant miRNA-21. Results represent the means and standard deviations from three independent triplicated experiments (N = 6), (*p < 0.05)