Abstract: In this study,hydrogen peroxide (H₂O₂) was used to induce SH-SY5Y cells damage.The viability of SH-SY5Y cells was then measured with MTT assay.Cell apoptosis was detected with Hoechst staining.The expression of PCNA was determined with immunocytochemistry and western blotting.The results showed that 1.54 mmol/L H₂O₂ can significantly induce apoptosis,and decrease expression of PCNA in SH-SY5Y cells.After treatment with 39 mg/L (SPM-L) and 156 mg/L (SPM-H) of snail polypeptide mixture (SPM), H₂O₂-induced apoptosis cells were attenuated (H₂O₂ VS.SPM-L:58.39±8.67% VS.44.06±4.35%,P<0.05; H₂O₂ VS.SPM-H:58.39±8.67% VS.32.45±9.44%, P<0.01),while there was a concentration-dependent increase of PCNA expression in the SPM groups.These results suggested that the SPM can protect against H₂O₂-induced SH-SY5Y cells apoptosis,which may be correlated with up-regulated PCNA expression.

Key words: snail polypeptide, hydrogen peroxide, SH-SY5Y cell, apoptosis, PCNA