中华皮肤科杂志 ›› 2009, Vol. 42 ›› Issue (3): 167-170.

• 论著 • 上一篇    下一篇

雷公藤内酯醇对HaCaT细胞IFN-γ信号转导途径的影响

涂红琴 李新宇 顾恒   

  1. 中国医学科学院皮肤病研究所 南京医科院皮研所 南京医科院皮研所
  • 收稿日期:2008-09-03 修回日期:2008-09-26 出版日期:2009-03-15 发布日期:2009-03-15
  • 通讯作者: 涂红琴 E-mail:tuhqin@163.com

Effects of triptolide on interferon-γ signaling in a human keratinocyte cell line HaCaT

  • Received:2008-09-03 Revised:2008-09-26 Online:2009-03-15 Published:2009-03-15

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摘要：

目的 研究雷公藤内酯醇对人角质形成细胞永生化株HaCaT细胞中IFN-γ信号转导途径的影响。方法 不同浓度雷公藤内酯醇（10-10 ～ 10-7 mol/L）预处理HaCaT细胞2 h后，用重组人IFN-γ（rhIFN-γ，500 U/mL）刺激诱导细胞，在不同的时间收集细胞，提取细胞总蛋白，免疫印迹法检测IFN-γ信号途径中IFN-γ受体α（IFN-γRα）、磷酸化Janus激酶2（pJAK2）、细胞因子信号转导抑制因子1（SOCS1）表达情况。结果 10-8 mol/L及10-7 mol/L雷公藤内酯醇可明显抑制HaCaT细胞中IFN-γ诱导的IFN-γRα蛋白表达（P < 0.05，P < 0.05）；10-9 mol/L及10-8 mol/L雷公藤内酯醇可明显抑制IFN-γ诱导的pJAK2蛋白表达（P < 0.05，P < 0.05）。雷公藤内酯醇对IFN-γRα表达及JAK2磷酸化的抑制作用呈剂量依赖性，其半数抑制浓度（IC50值）分别为1.37 × 10-8 mol/L和2.83 × 10-9 mol/L。10-10，10-9，10-8 mol/L的雷公藤内酯醇作用HaCaT细胞2 h后可明显上调IFN-γ诱导的SOCS1蛋白表达（P < 0.05，P < 0.01，P < 0.01），其半数有效剂量（ED50值）为3.32 × 10-11 mol/L。结论 雷公藤内酯醇可分别通过抑制HaCaT细胞中IFN-γRα表达、JAK2磷酸化以及上调SOCS1表达，从不同时相的3个环节，共同抑制HaCaT细胞中STAT-1磷酸化，从而抑制IFN-γ信号所诱导的多种炎症相关基因转录。这种抑制作用可能是雷公藤治疗银屑病等IFN-γ依赖性炎症性皮肤病有效的重要机制之一。

关键词: 雷公藤内酯醇;γ-干扰素;γ-干扰素受体;Janus激酶;细胞因子信号转导抑制因子

Abstract:

Objective To investigate the effects of triptolide on the expression of a series of proteins associated with interferon-γ （IFN-γ） signaling in HaCaT keratinocytes. Methods After pretreatment with different dosages of triptolide （10-10 - 10-7 mol/L）, HaCaT cells were stimulated by recombinant human IFN-γ （rhIFN-γ, 500 U/mL） for various periods followed by the collection of cells. Then, total protein was extracted from these cells and subjected to Western blotting for the detection of expression of interferon-γ receptor α （IFN-γRα）, phosphorylated Janus kinase 2 （pJAK2） and suppressor of cytokine signaling （SOCS1）. Results Triptolide at the concentrations of 10-8 mol/L and 10-7 mol/L significantly inhibited the IFN-γRα expression upregulated by rhIFN-γ （both P < 0.05）. The expression of pJAK2 induced by rhIFN-γ was also suppressed by triptolide at the concentrations of 10-9 mol/L and 10-8 mol/L （both P < 0.05）. The inhibition of triptolide on IFN-γRα and pJAK2 expression was dose-dependent and the 50% inhibitory concentrations （IC50 value） were 1.37 × 10-8 mol/L and 2.83 × 10-9 mol/L, respectively. On the contrary, triptolide upregulated the expression of SOCS1 stimulated by rhIFN-γ at the concentrations of 10-10, 10-9 and 10-8 mol/L （P < 0.05, 0.05, 0.01, respectively） with the 50% effective dosage （ED50 value） at 3.32 × 10-11 mol/L. Conclusions By inhibiting the expression of IFN-γRα as well as phosphorylation of JAK2 and upregulating the expression of SOCS1, triptolide inhibits the phosphorylation of STAT-1, resulting in the inhibition of genetic transcription of multiple inflammatory factors induced by IFN-γ signaling in HaCaT keratinocytes, and the inhibition probably contributes to the efficacy of triptolide in the treatment of IFN-γ-dependent inflammatory skin disorders, such as psoriasis.

Key words: Triptolide;Interferon-γ;Interferon-γ receptor;Janus kinase;Suppressor of cytokine signaling