Fig. 7

MEK1/2 kinase involvement in neurite outgrowth. SH-SY5Y cells were treated with ATRA and EC23 with/without U0126 MEK1/2 inhibitor for 5 days, and then neuronal differentiation was evaluated by immunofluorescence and morphometric analysis using βIII tubulin antibody. Neurite outgrowth was significantly reduced after applying U0126. Typical micrographs are shown in a) DMSO CT, b) MEK1/2 inhibitor, c) 10 μM of ATRA and MEK1/2 inhibitor, d) 10 μM ATRA, e) 10 μM of EC23 and MEK1/2 inhibitor, f) SH-SY5Y cells with 10 μM EC23 (scale bar = 18 μm). Error bars indicate SEM of three biological replicates (** p < 0.01; *** p < 0.001; **** p < 0.0001 two-way ANOVA with Sidak’s multiple comparison test)