姜黄素下调NF-κB信号通路抑制化学缺氧诱导的U87细胞炎症反应

Curcumin inhibits chemical hypoxia-induced astrocyte inflammation

目的研究姜黄素对化学缺氧所致人源性神经星形胶质瘤细胞系U87炎症反应的影响,并探讨相关分子机制。方法100μmol/L CoCl_2处理U87细胞不同时间(1、3、6、12、24 h),实时荧光定量PCR(qRT-PCR)法检测炎症因子白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α) mRNA表达变化。100μmol/L CoCl_2处理U87细胞12 h制备化学缺氧模型,同时给予1、5和10μmol/L姜黄素处理,对照组(不添加CoCl_2)和模型组给予等体积DMSO;qRTPCR法检测IL-1β、IL-6、TNF-αmRNA表达变化;Western Blotting法检测NF-κB/P65蛋白磷酸化水平及核转位。结果CoCl_2上调U87细胞IL-1β、IL-6、TNF-αmRNA水平并呈时间相关性,炎症反应在约12 h达到高峰。与模型组比较,姜黄素显著下调炎症因子IL-1β、IL-6和TNF-α的mRNA水平,5和10μmol/L浓度组差异显著(P<0.05);显著下调p65的磷酸化水平(P<0.05);导致细胞核内NF-κB/p65蛋白显著减少、细胞质中NF-κB/p65蛋白显著增加(P<0.05)。结论姜黄素通过下调NF-κB信号通路抑制化学缺氧诱导的U87细胞炎症反应。

Objective to investigate effects of traditional Chinese herbal extract monomer-curcumin(Cur) on astrocyte inflammation induced by hypoxia. Methods cobalt chloride(CoCl2) was applied to the astrocyte cell line U87 resulting in cellular hypoxia. The changes of inflammatory cytokines after hypoxia and Cur treatment were determined by real-time reverse transcription polymerase chain reaction. The effects of Cur on NF-κB signaling pathway and nuclear translocation in hypoxic U87 cells were studied by Western Blotting. Results CoCl2 up-regulated the transcriptional level of astrocyte inflammatory cytokines in a dose-dependent manner, and Cur significantly inhibited inflammation of astrocyte induced by chemical hypoxia. CoCl2-induced chemical hypoxia lead to increased phosphorylation of p65 in the cytosol and promotes nuclear translocation of p65. Cur pretreatment significantly inhibited the activation of the above signaling pathway. Conclusion Cur exerts neuroprotective effects by inhibiting NF-κB signaling pathway and down-regulation of astrocyte inflammation induced chemical hypoxia.