The Role Of Mitochondria In PDBE-47Induced Apoptosis In SH-SY5Y Cells

Recently, neurodevelopmental toxicity of polybrominated diphenyl ethers （PBDEs）attracted more attention, but the exact mechanism is not fully understood. The experimentsusing PBDE-47in human neuroblastoma （SH-SY5Y） cells were observed the percentages ofapoptosis, the changes of mitochondrial membrane potential （ΔΨm）, mitochondrial Ca²⁺concentration ([Ca²⁺]m) and the Cyt C expression levels to explore the role of mitochondriain PBDE-47induced apoptosis in SH-SY5Y cells, and provide a theoretical basis for thestudies of neurotoxic effects of PBDEs.Part1Effects of PBDE-47on apoptosis, mitochondrial membrane potential andmitochondrial Ca²⁺concentration in SH-SY5Y cellsObjective: To study the effects of different concentrations of PBDE-47on the percentagesof apoptosis, mitochondrial membrane potential and mitochondrial Ca²⁺concentration inSH-SY5Y cells in vitro.Methods: Cells were stained by the fluorescent probe JC-1and Rhod-2/AM, and thechanges of percentages of apoptosis and ΔΨmwere detected in SH-SY5Y cells using flowcytometry, the changes of [Ca²⁺]mwere detected by a fluorescence microplate reader.Results: Compared with the solvent control group, the percentages of early and totalapoptosis were significantly higher （P <0.05）, the mitochondrial membrane potential wasdecreased （P <0.05） in10μmol/L PBDE-47exposured group;[Ca²⁺]mof10μmol/LPBDE-47exposed group was significantly decreased （P <0.05）.Conclusion: PBDE-47can lead SH-SY5Y cells to decrease the levels of ΔΨm and [Ca²⁺]m, which may be related to induce apoptosis.Part2Effects of PBDE-47on the mRNA and protein expressions of cytochrome c inSH-SY5Y cellsObjective: To explore the effects of PBDE-47on the changes of mRNA and proteinexpressions of cytochrome c.Methods: Cytoplasmic RNA was extracted to detect Cyt C mRNA expression using theRT-PCR assay. At the same time, the protein was separated and extracted to detect theprotein expression levels of cytoplasmic and mitochondrial Cyt C by Western blot.Results: Compared with the solvent control group, cytoplasmic Cyt C mRNA expressionlevel was significantly increased in10μmol/L PBDE-47treated group （P <0.05）; comparedwith the control group, cytoplasmic Cyt C protein levels of5,10μmol/L PBDE-47exposedgroups were significantly increased, mitochondrial Cyt C protein levels were significantlydecreased in various concentrations of PBDE-47exposed groups （P <0.05）.Conclusion: PBDE-47can lead to Cyt C from mitochondria transfer to the cytoplasm,which may activate mitochondrial singaling pathway and induce apoptosis.