PCB153对PBDE-47致SH-SY5Y细胞DNA损伤和修复基因表达的影响

目的探讨PCB153和PBDE-47单独及联合染毒对SH-SY5Y细胞DNA损伤及其修复基因表达的影响。方法设DMSO溶剂对照组,1、5、10μmol/LPBDE-47(低、中、高)单独染毒组和与5μmol/L PCB153联合染毒组及相应的抗氧化剂组(N-乙酰-L-半胱氨酸NAC100μmol/L),分别对SH-SY5Y细胞染毒24h。用单细胞凝胶电泳试验测定DNA损伤情况,用RealTime PCR检测DNA损伤修复酶XRCC1及XRCC3mRNA表达情况。结果中、高剂量单独染毒组和中、高剂量联合染毒组细胞尾部DNA百分率、Olive尾距均显著高于对照组(P<0.05),且呈现明显的剂量-效应关系,中、高联合染毒组细胞尾部DNA百分率、Olive尾距均显著高于相应的PBDE-47或PCB153单独染毒组(P<0.05),加入抗氧化剂后其细胞尾部DNA百分率及Olive尾距均明显下降(P<0.05),高剂量联合组对细胞DNA损伤具有交互作用(F=23.74,P<0.01);高剂量染毒组及中、高剂量联合染毒组XRCC1mRNA表达与对照组相比均明显下降(P<0.05),加入抗氧化剂后其XRCC1mRNA表达上升(P<0.05);高剂量单独和联合染毒组XRCC3mRNA表达与对照组相比均明显上升(P<0.05),加入抗氧化剂后可使XRCC3mRNA表达明显下降(P<0.05)。相关分析结果表明,细胞DNA损伤与XRCC1mRNA的表达呈负相关,与XRCC3mRNA的表达呈正相关(r分别为0.74,0.76,P<0.05)。结论一定剂量的PBDE-47可导致DNA损伤和影响DNA损伤修复基因的表达,PCB153可增强PBDE-47对细胞DNA的损伤作用,氧化应激可能在PBDE-47致DNA损伤过程中发挥了重要作用。

Effects of PCB153 on DNA damage and DNA repair-related genes expressions induced by PBDE-47 in human neuroblastoma cells in vitro

Objective To explore the effects of PCB153 on DNA damage and DNA repair-related gene expressions induced by PBDE-47 in SH-SY5Y cells.Methods SH-SY5Y cells were incubated with different concentrations of 1,5 and 10μmol/L PBDE-47 or/and 5μmol/L PCB153 and antioxidant n-acetyl cysteine(NAC 100μmol/L) for 24h in vitro,percentage of DNA in the tail,olive tail moment,the mRNA expression levels of XRCC1 and XRCC3 were measured respectively.Results PBDE-47 increased percentage of DNA in the tail and olive tail moment significantly at doses of 5 μmol/L and above in a concentration-dependent manner compared to the control(P<0.05).The percentage of DNA in the tail and olive tail moment were significantly higher in cells treated by 5μmol/L PBDE-47+5μmol/L PCB153 and 10μmol/L PBDE-47+5μmol/L PCB153 groups compared to the corresponding doses of PBDE-47 groups or PCB153 group(P<0.05).The percentage of DNA in the tail and olive tail moment of cells treated by the groups added NAC were obviously lower than that of their corresponding groups not added it(P<0.05).The interactive action was observed between PBDE-47 and PCB153 at concentrations of 10μmol/L PBDE-47(F=23.74,P<0.01).Significant decreased XRCC1 mRNA expression were observed at 10μmol/L PBDE-47,5μmol/L PBDE-47+5μmol/L PCB153,and 10μmol/L PBDE-47+5μmol/L PCB153 groups while significant increased XRCC3 mRNA expression were observed at 10μmol/L PBDE-47 and 10μmol/L PBDE-47+5μmol/L PCB153 compared to the control group(P<0.05).XRCC1 mRNA expression in cells treated by 100μmol/L NAC+10μmol/L PBDE-47+5μmol/L PCB153 group was significantly higher than that in 10μmol/L PBDE-47+5μmol/L PCB153 group(P<0.05).XRCC3 mRNA expression in cells treated by PBDE-47 antioxidant groups were significantly lower than that in their corresponding non-antioxidant groups(P<0.05).Correlation analysis showed there was a negative relationship between DNA damage and XRCC1 mRNA expression while a positive relationship between DNA damage and XRCC3 mRNA expression(r_1=0.74,r_2=0.76,P<0.05).Conclusion PBDE-47 can induce DNA damage,PBDE-47 combined with PCB153 may increase the effects on DNA damage in SH-SY5Y cells in vitro,oxidative stress may play a important role in DNA damage induced by PBDE-47.