Study On The Protective Mechanism Of Scallop Skirt-glycosaminoglycan On6-OHDA-induced Apoptosis In SH-SY5Y Cells

Objective:To investigate the effect of scallop skirt-glycosaminoglycan (SS-GAG) on the content of MDA, the activity of LDH, the apoptosis and the expression of several apoptosis-related genes and proteins in SH-SY5Y cells induced by6-OHDA and then study the protective mechanism of SS-GAG on dopaminergic neurons.Methods:Human neuroblastoma SH-SY5Y cells were divided into control group,6-OHDA destroy group and3treatment groups treated with6-OHDA and SS-GAG (200,400and800μg/ml).The content of MDA and the activity of LDH were measured, the mRNA expressions of Bcl-2and Bax genes were evaluated by real-time PCR, the protein content of Cyt C in cytoplasm were analyzed by Western blotting, and the percentage of apoptosis and the activation of Caspase-9was measured by flow cytometry.Results:Compared with the control group, all items of the6-OHDA destroy group have remarkable differences (P<0.01):the content of MDA and the activity of LDH were increased, the percentage of early apoptosis was elevatory, the mRNA expression of Bcl-2was reduced, the mRNA expression of Bax was heightened, the protein content of Cyt C in cytoplasm was increased, and the number of cells expressing activated Caspase-9was elevated. After pretreatment with SS-GAG, the content of MDA and the activity of LDH were decreased, the percentage of early apoptosis was reduced, the expression of Bcl-2was increased, the expression of Bax and the content of Cyt C in cytoplasm were decreased, and the expression of activated Caspase-9was reduced.Conclusion:SS-GAG could reduce the damage of oxidative stress induced by6-OHDA. It may inhibit apoptosis of SH-SY5Y cells by up-regulating Bcl-2transcription, down-regulating Bax transcription, inhibiting Cyt C’s release from mitochondria to cytoplasm, and then inhibiting the activation of Caspase-9.