Polyamine depletion inhibits NF-κB binding to DNA and interleukin-8 production in human chondrocytes stimulated by tumor necrosis factor-α
Polyamine depletion inhibits NF-κB binding to DNA and interleukin-8 production in human chondrocytes stimulated by tumor necrosis factor-α
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DOI：
10.1002/jcp.20368
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发表时间：
2005-09-01
影响因子：
5.6
通讯作者：
Flamigni, F
中科院分区：
文献类型：
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作者：
Facchini, A;Borzi, RM;Flamigni, F
促炎细胞因子（如肿瘤坏死因子α (TNF α)）激活NF-kappa B通路可能是软骨细胞基因表达重编程的重要因素，从而使其成为关节疾病的治疗靶点。为了寻找限制软骨损伤的新方法，我们使用α -二氟甲基鸟氨酸（DFMO），一种特异性多胺生物合成抑制剂，研究了人类C-28/12软骨细胞中tnf - κ B活化对多胺的要求。NF-kappa B通路是通过使用药理学抑制剂或通过表达一个跨显性I κ B α超抑制因子来解剖的。用TNFa处理C-28/12软骨细胞导致p65 nf - κ B亚基的核定位和DNA结合活性迅速增强。TNF α还增加了白细胞介素-8 （IL-8）的水平和细胞外释放，IL-8是一种CXC趋化因子，以nf - κ b依赖的方式在关节炎中起作用。用DFMO预处理软骨细胞，在引起多胺耗竭的同时，显著降低NF-kappa B DNA结合活性。此外，DFMO还能在不影响细胞活力的情况下降低IL-8的产生。通过共加腐胺来恢复多胺水平可以绕过DFMO的抑制作用。我们的研究结果表明，细胞内多胺的消耗通过干扰NF-kappa B的DNA结合活性来抑制软骨细胞对tnf fa的反应。这表明，通过药理学和/或遗传方法来消耗软骨细胞中的多胺池可能是一种有效的方法，可以减少关节炎中炎症细胞因子对NF-kappa B的激活，而不会引起软骨细胞凋亡。
The activation of the NF-kappa B pathway by pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF alpha), can be an important contributor for the re-programming of chondrocyte gene expression, thereby making it a therapeutic target in articular diseases. To search for new approaches to limit cartilage damage, we investigated the requirement of polyamines for NF-kappa B activation by TNFa in human C-28/12 chondrocytes, using alpha-difluoromethylornithine (DFMO), a specific polyamine biosynthesis inhibitor. The NF-kappa B pathway was dissected by using pharmacological inhibitors or by expressing a transdominant I kappa B alpha super repressor. Treatment of C-28/12 chondrocytes with TNFa resulted in a rapid enhancement of nuclear localization and DNA binding activity of the p65 NF-kappa B subunit. TNF alpha also increased the level and extracellular release of interleukin-8 (IL-8), a CXC chemokine that can have a role in arthritis, in an NF-kappa B-dependent manner. Pre-treatment of chondrocytes with DFMO, while causing polyamine depletion, significantly reduced NF-kappa B DNA binding activity. Moreover, DFMO also decreased IL-8 production without affecting cellular viability. Restoration of polyamine levels by the co-addition of putrescine circumvented the inhibitory effects of DFMO. Our results show that the intracellular depletion of polyamines inhibits the response of chondrocytes to TNFa by interfering with the DNA binding activity of NF-kappa B. This suggests that a pharmacological and/or genetic approach to deplete the polyamine pool in chondrocytes may represent a useful way to reduce NF-kappa B activation by inflammatory cytokines in arthritis without provoking chondrocyte apoptosis.