Objective: To explore the role of Notch signaling pathway and the effect of γ-secretase inhibitor (DAPT) on the apoptosis induced by 1-methyl-4-phenylpyridinium (MPP(+)) in differentiated SH-SY5Y cell.
Methods: SH-SY5Y cell were incubated with various concentrations (0, 0.5, 1, 1.5, 2 mmol/L) of MPP(+) for 0, 24, 48 and 72 h respectively. Flow cytometry with Annexin V-FITC/PI double staining was used for apoptotic analysis. The protein expressions of Notch-1, Jagged-1 and Hes-1 were detected by Western blot. SH-SY5Y cell were preincubated with 10 µmol/L DAPT for 15 min before 1.5 mmol/L MPP(+) treatment for 48 h. Flow cytometry and Western blot were performed to analyze the cell apoptosis and protein expressions of Notch-1, Jagged-1 and Hes-1.
Results: MPP(+) induced the apoptosis of SH-SY5Y cell in a dose (3.20% ± 0.19% vs 10.00% ± 1.72%, 20.60% ± 3.76%, 32.80% ± 5.12%, 46.00% ± 5.06%, all P < 0.05) and time- (2.80% ± 0.21% vs 12.30% ± 1.82%, 19.60% ± 2.89%, 35.00% ± 4.78%, all P < 0.05) dependent manner. MPP(+) up-regulated the expressions of Notch-1, Jagged-1 and Hes-1 in a dose- and time-dependent manner in SH-SY5Y cell. DAPT treatment decreased MPP(+)-induced apoptosis (3.10% ± 0.21% vs 35.50% ± 4.98%, 19.20% ± 2.98%, both P < 0.05) and the expressions of Notch-1, Jagged-1 and Hes-1 in SH-SY5Y cell.
Conclusion: The activation of Notch signaling pathway plays an important role in MPP(+)-induced apoptosis of SH-SY5Y cell. DAPT inhibits Notch signaling pathway and protects SH-SY5Y cell from MPP(+)-induced apoptosis.