Figure 4. ERK signaling regulates mucin expression enhanced by diquafosol tetrasodium in HCECs. A: Inhibition of MUC1, MUC16, and MUC5AC mRNA levels by ERK inhibitor. B: Representative photograph of MUC1 and MUC16 protein levels and relative expression results for both markers with ERK inhibitor. All relative signal intensities were normalized against β-actin. C: Inhibition of MUC5AC secretion by ERK inhibitor in HCECs. Concentrations of MUC5AC in HCECs were quantitatively analyzed by ELISA. * p<0.05, ** p<0.01 versus control; # p<0.05, ## p<0.01 versus without ERK inhibitor.