IL-1β对HepG2细胞核受体RXRα蛋白表达的影响

Effect of Interleukin 1 Beta on Expression of Nuclear Receptor RXRα in HepG2 Cells

目的研究白细胞介素1β(interleukin 1 beta,IL-1β)诱导人肝癌细胞HepG2维甲酸X受体α(retinoid Xreceptor alpha,RXRα)蛋白核-胞浆转移现象及其基因水平变化。方法 IL-1β处理HepG2细胞,收集不同时间点RXRα总蛋白、胞浆蛋白、核蛋白及mRNA;同时用蛋白酶体抑制剂,MG132预处理HepG2细胞后IL-1β诱导细胞,收集细胞蛋白及mRNA,应用Western blot及实时荧光定量聚合酶链反应(real-time fluorescent quantitative polymerase chain reaction,real-time PCR)检测RXRα总蛋白、胞浆蛋白、核蛋白及mRNA水平的变化。结果总胞核RXRα蛋白表达量降低(P<0.05),胞浆RXRα蛋白表达量增高(P<0.05),RXRαmRNA水平在6、12 h升高(P<0.05)。MG132可以抑制IL-1β对细胞核、胞浆RXRα蛋白表达水平的变化。结论 IL-1β可以诱导HepG2细胞RXRα核-胞浆转移,RXRα核-胞浆转移可能与泛素-蛋白酶体降解途径相关。

Objective To investigate the effects of interleukin 1 beta（IL-1β） treatment on the gene expression of retinoid X receptor alpha（RXRα） in human liver-derived HepG2 cells.Methods Total,nuclear and cytoplasm protein and mRNA in IL-1β treated HepG2 cells were harvested in different timepoints.After pre-treatment with the proteasome inhibitor MG132,total cell protein or nuclear,cytosolic fraction and mRNA were extracted from cells treated with IL-1β.Western blot and quantitative real time PCR were applied to detect the expressions of RXRα protein and gene.ResultsAfter IL-1β treatment,total and nuclear protein levels of RXRα were suppressed（P〈0.05）,while the cytoplasm level of RXRα protein was increased（P〈0.05）.The mRNA expression level of RXRα was increased at 6 and 12 hours（P〈0.05）.MG132 could block IL-1β-mediated nuclear export of RXRα.Conclusion IL-1β can induce the nucleo-cytoplasmic translocation of RXRα protein in HepG2 cell,which may be associated with Ubiquitin-proteasome-dependent degradation.