Daidzein suppresses pro-inflammatory chemokine Cxcl2 transcription in TNF-α-stimulated murine lung epithelial cells via depressing PARP-1 activity
Daidzein suppresses pro-inflammatory chemokine Cxcl2 transcription in TNF-α-stimulated murine lung epithelial cells via depressing PARP-1 activity
复制标题
大豆黄酮通过抑制 PARP-1 活性抑制 TNF-α 刺激的小鼠肺上皮细胞中促炎趋化因子 Cxcl2 转录
DOI：
10.1038/aps.2013.191
复制
发表时间：
2014-04-01
影响因子：
8.2
通讯作者：
Ba, Xue-qing
中科院分区：
文献类型：
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作者：
Li, Hai-yan;Pan, Lang;Ba, Xue-qing
目的：大豆苷元（4′，7-二羟基异黄酮）是一种存在于多种草药中的具有抗炎活性的异黄酮。本研究旨在探讨其对小鼠肺上皮细胞抗炎作用的机制。方法：将C57BL/6小鼠鼻内暴露于tnf - α诱导肺部炎症。小鼠在tnf - α激发前注射大豆苷元（400 mg/kg, ip）， tnf - α激发后12 h处死，收集肺组织进行分析。在体外研究中，小鼠MLE-12上皮细胞用tnf - α (20 ng/mL)处理。采用实时PCR和双报告基因法检测促炎趋化因子Cxcl2 mRNA的表达和NF-kappa B的转录活性。采用Western blotting和免疫沉淀法检测蛋白多磷酸腺苷核糖基化（PARylation）。结果：大豆苷元预处理小鼠可明显减轻tnf - α诱导的肺部炎症，抑制肺组织中Cxcl2的表达。此外，大豆苷元（10 μ mol/L）可抑制tnf - α诱导的MLE-12细胞Cxcl2表达、活性和NF-kappa B转录活性的升高，并显著抑制tnf - α诱导的MLE-12细胞PARylation。在共转染PARP-1表达质粒和NF-kappa B-luc（或Cxcl2-luc）报告质粒的MLE-12细胞中，TNF-a显著增加NF-kappa B（或Cxcl2）的激活，而在大豆苷元（或蛋白PARylation抑制剂pj34）存在时，NF-kappa B（或Cxcl2）的激活显著减弱。PARP-1活性测定表明，10 μ mol/L的大豆苷元可使PARP-1活性降低75%。结论：大豆苷元在小鼠肺上皮细胞中的抗炎作用似乎是通过与PARP-1的直接相互作用介导的，PARP-1抑制了促炎趋化因子如Cxcl2转录调节所需的RelA/p65蛋白PARylation。
Aim: Daidzein (4 ',7-dihydroxyisoflavone) is an isoflavone exiting in many herbs that has shown anti-inflammation activity. The aim of this study was to investigate the mechanism underlying its anti-inflammatory action in murine lung epithelial cells.Methods: C57BL/6 mice were intranasally exposed to TNF-alpha to induce lung inflammation. The mice were injected with daidzein (400 mg/kg, ip) before TNF-alpha challenge, and sacrificed 12 h after TNF-alpha challenge, and lung tissues were collected for analyisis. In in vitro studies, murine MLE-12 epithelial cells were treated with TNF-alpha (20 ng/mL). The expression of pro-inflammatory chemokine Cxcl2 mRNA and NF-kappa B transcriptional activity were examined using real-time PCR and a dual reporter assay. Protein poly-adenosine diphosphate-ribosylation (PARylation) was detecyed using Western blotting and immunoprecipitation assays.Results: Pretreatment of the mice with daidzein markedly attenuated TNF-alpha-induced lung inflammation, and inhibited Cxcl2 expression in lung tissues. Furthermore, daidzein (10 mu mol/L) prevented TNF-alpha-induced increases in Cxcl2 expression and activity and NF-kappa B transcriptional activity, and markedly inhibited TNF-alpha-induced protein PARylation in MLE-12 cells in vitro. In MLE-12 cells co-transfected with the PARP-1 expression plasmid and NF-kappa B-luc (or Cxcl2-luc) reporter plasmid, TNF-a markedly increased NF-kappa B (or Cxcl2) activation, which were significantly attenuated in the presence of daidzein (or the protein PARylation inhibitor PJ 34). PARP-1 activity assay showed that daidzein (10 mu mol/L) reduced the activity of PARP-1 by similar to 75%.Conclusion: The anti-inflammatory action of daidzein in murine lung epithelial cells seems to be mediated via a direct interaction with PARP-1, which inhibits RelA/p65 protein PARylation required for the transcriptional modulation of pro-inflammatory chemokines such as Cxcl2.