FIGURE 6.

Guanine activates sGC-cGMP-PKG-ERK signaling pathway in SH-SY5Y neuroblastoma cells. Representative Immunoblot analysis of ERK1/2 expression in SH-SY5Y cells, with β-actin as loading control, and the correspondent quantitative data of densitometric analysis. Cells were cultured for 24 h and exposed for 30 min to 100 μM GUA, 50 μM GUA, a phosphodiesterase inhibitor (10 μM IBMX), a NOS inhibitor (1 mM L-NAME), a sGC inhibitor (10 μM ODQ), an EPAC specific cAMP analog (2,5 μM 8-CPT-cAMP), a CaMKII inhibitor (20 μM KN-93). Each column represents the mean ± SEM of at least three independent experiments, and it is expressed as relative protein expression normalized to β-actin. Student’s t-test: ^∗∗∗P < 0.001, vs. untreated cells (Basal); ^#P < 0.05, ^###P < 0.001, vs. GUA-treated cells, ^§P < 0.05, vs. GUA- and L-NAME-treated cells.