Fig. 3.

ERK 5 signaling mediates NGF- and PC-induced neuroprotection against H₂O₂. PC12 cells were pre-treated with BIX01288 or BIX01289 (specifically inhibiting ERK5 activation) for 30 min before NGF or PC was applied for 24 h. Then cells were stressed with H₂O₂ for another 24 h before cell viability was assessed (n = 3). The ERK5 inhibitors blocked the protective effect of NGF (A) and PC (B). BIX01288 or BIX01289 alone did not rescue the cells from H₂O₂ (a, b). NGF, PC or the inhibitors alone did not affect cell viability (c) (**, @@: p < 0.01; ***, ###, @@@: p < 0.001; ns no significance)