雷公藤内酯醇对人外周血单一核细胞γ-干扰素产生及对转录激活物-1磷酸化和白介素-8表达的影响

Effects of Triptolide on the Production of Interferon-γ in Human Peripheral Blood Mononuclear Cell and Phosphorylation of Signal Transducer and Activator of Transcription-1 and Production of Interleukin-8

目的研究雷公藤内酯醇对人外周血单一核细胞(PBMC)中γ-干扰素(IFN-γ)的产生、以及由此引起的角质形成细胞分泌白介素-8(IL-8)和IFN-γ信号转导途径的影响。方法体外通过植物血凝素(PHA-L)刺激人PBMC和用重组人γ-干扰素(rhIFN-γ)作为刺激信号诱导HaCaT细胞,ELISA方法检测IFN-γ和IL-8的产生,免疫印迹法检测总信号转导和转录激活物-1(STAT1)及其磷酸化STAT1的表达。结果雷公藤内酯醇可剂量依赖性地抑制PHA-L诱导的人PBMCIFN-γ蛋白产生(P<0.05,P<0.01,P<0.001),其半数抑制浓度(IC50值)为5.96×10-11mol/L。对rhIFN-γ引起的HaCaT细胞IL-8分泌升高现象亦有显著抑制作用(P<0.001),IC50值约为1.15×10-13mol/L。对1000U/mlrhIFN-γ刺激的HaCaT细胞总的STAT1表达无影响,显著抑制磷酸化STAT1的表达(P<0.01),IC50值约为9.45×10-11mol/L。结论雷公藤内酯醇对IFN-γ的产生、以及由此引起的信号转导途径中STAT1的磷酸化和产生IL-8的病理性效应3个关键环节均有显著的抑制作用。

Objective To investigate the effects of triptolide on the production of interferon-γ （ IFN-γ） in human peripheral blood mononuclear cell （PBMC） and intedeukin-8 （IL-8） in HaCaT keratinocytes and phosphorylation of signal transducer and activator of transcription-1 （ STAT1 ） of IFN-γsignal transduction pathways in HaCaT cells. Methods Human PBMC was induced by phytohaemagglutinin （PHA-L） and HaCaT cells were stimulated by recombinant human IFN-γ （rhIFN-γ）. The productions of IFN-γand IL-8 in cells were detected by ELISA. The expression of STAT1 and its phosphorylation were analyzed by Western blot. Results Triptolide inhibited the production of IFN-γin human PBMC induced by PHA-L in a dose-dependent manner （P 〈 0. 05, P 〈 0. 01, P 〈 0. 001 ） and the 50% inhibitory concentration （IC50） value was 5.96 × l0^- 11 mol/L. IL-8 production in HaCaT cells induced by rhlFN-γin vitro was also inhibited by triptolide （P 〈 0. 001 ） and the IC50 value was about 1.15 × 10^-13mol/L. The expressions of phosphorylated STAT1 in HaCaT cells stimulated by rhIFN-γwas inhibited by triptolide （ P 〈 0. 01 ） and the IC50 value was about 9.45 × 10 ^-11 mol/L. Conclusion Triptolide can inhibit the production of IFN-γ in human PBMC and downregulate IL-8 level in HaCaT keratinocytes induced by rhIFN-γ. Triptolide can inhibit the phosphorylations of STAT1 of IFN-γ signal pathway in HaCaT keratinocytes stimulated by IFN-γ.