FIGURE 4.

The neuroprotective effects of extracellular ATP against glutamate involves Erk1/2 signaling pathway. Cultured SH-SY5Y cells were treated with 10 mM Glu in the presence or absence of ATP (5 and 10 μM). The control group consists of the untreated cells. (A) The protein expression of p-Erk1/2 and Erk1/2 were determined by western blotting, and the quantitation of p-Erk1/2 and Erk1/2 expressions were calibrated. Expression of GAPDH was served as loading control. (B) CCK-8 kit was performed to evaluated cell viability. (C) All treated SH-SY5Y cells were stained with DCFH-DA, and fluorescent density mean of ROS level was calibrated. Scale bar = 100 μm under 20× magnification. (D) All treated SH-SY5Y cells were stained with JC-1 kit, and the ratio of the red/green fluorescence optical density were analyzed. Scale bar = 100 μm under 20× magnification. All data in bar charts present mean ± SEM from at least three independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001 versus the ATP treated group or the glutamate group. n.s., no significance.