锌离子螯合剂对脂多糖诱导的小胶质细胞中细胞因子表达的影响

Effect of zinc chelator on lipopolysaccharide-induced cytokine expression in microglial cells

目的研究锌离子螯合剂四吡啶甲基乙二胺(TPEN)对脂多糖(LPS)诱导的小胶质细胞中细胞因子表达的影响及机制。方法体外培养小鼠小胶质瘤细胞系小胶质细胞后分为对照组、LPS组(100 ng/ml LPS,30 min或4h)、TPEN+LPS组(25μmol/L TPEN,1 h+LPS,30 min或4 h)、细胞外信号调节激酶(ERK)抑制剂PD98059+LPS组(PD98059+LPS组,25μmol/L PD98059,30 min+LPS,4 h),采用实时定量PCR法分析细胞因子白细胞介素(IL)-1β、IL-6、TNF-αmRNA的表达,Western blot法检测pERK1/2蛋白的表达。结果与对照组比较,LPS组pERK1/2蛋白表达和IL-1β、IL-6、TNF-αmRNA表达明显升高(P<0.05,P<0.01);与LPS组比较,TPEN+LPS组pERK1/2蛋白表达和IL-1β、IL-6、TNF-αmRNA表达明显降低(P<0.05,P<0.01),而PD98059+LPS组IL-1β、IL一6、TNF-αmRNA表达明显降低(P<0.01)。结论 TPEN可能通过减少pERK1/2表达来抑制LPS诱导的细胞因子的大量释放。

Objective To study the effect of zinc chelator（TPEN） on lipopolysaccharide（LPS）-in- duced cytokine expression in microglial cells. Methods In vitro cultured mouse microglial cells were divided into normal control group,LPS group（treated with 100 ng/ml LPS for 30 min or 4 h） ,TPEN＋LPS group（treated with 25 μmol/L TPEN for 30 min or 4 h and＋LPS for 1 h） ,and ERK inhibitor PD98059＋LPS group（treated with 25 μmol/L PD98059 for 4 h and＋LPS for 30 min）. Expressions of IL-1β, IL-6 and TNF-α mRNA were detected by RT-PCR. Expression of pERK1/2 protein was detected by Western blot. Results The expression levels of pERK1/2 pro- tein and IL-1β,IL-6 and TNF-α mRNA were significantly higher in LPS group than in normal con- trol group（P〈0.05,P〈0.01） and significantly lower in TPEN＋LPS group than in LPS group （P〈0.05,P〈0.01）. The expression levels of IL-1β,IL-6 and TNF-α mRNA were significantly lower in PD98059＋LPS group than in LPS group（P〈0.01）. Conclusion TPEN inhibits LPS-in- duced massive release of cytokines possibly by down-regulating the expression of pERK1/2.