Autophagy Stimulus Promotes Early HuR Protein Activation and p62/SQSTM1 Protein Synthesis in ARPE-19 Cells by Triggering Erk1/2, p38^MAPK, and JNK Kinase Pathways

Figure 5

Effects of p38^MAPK, JNK, and cPKC inhibitors on HuR translocation, its phosphorylation, and p62 expression. Representative Western blotting (upper) and densitometric analysis (lower) of levels of HuR (a, d, g), phospho-HuR (p-HuR) (b, e, h), and p62 (c, f, i), in the cytoplasm of ARPE-19 cells exposed to either solvent or AICAR + MG132 (A + M) for 2 hrs, in the presence or not of p38^MAPK inhibitor (50 μM SB203580) (a–c), JNK inhibitor (10 μM SP600125) (d–f), or cPKC inhibitor (2 μM Gö6976) (g–i). Optical densities of HuR, phospho-HuR (p-HuR, in threonine residues), and p62 bands were normalized to α-tubulin, and the results expressed as mean percentages + S.E.M. (; , , and ; Tukey’s multiple comparison test).

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