Dependence on p38 MAPK signalling in the up-regulation of TLR2, TLR4 and TLR9 gene expression in Trichomonas vaginalis-treated HeLa cells
Dependence on p38 MAPK signalling in the up-regulation of TLR2, TLR4 and TLR9 gene expression in Trichomonas vaginalis-treated HeLa cells
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DOI：
10.1111/j.1365-2567.2006.02347.x
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发表时间：
2006-06-01
期刊：
影响因子：
6.4
通讯作者：
Kim, Soo-Ki
中科院分区：
文献类型：
--
作者：
Chang, Jae-Ho;Park, Ju-Youn;Kim, Soo-Ki
Toll 样受体 (TLR) 是模式识别受体 (PRR)，可识别微生物合成的保守病原体相关分子模式 (PAMP)。尽管原核感染对 TLR 是必需的，但阴道毛滴虫在皮肤粘膜屏障中 TLR 基因表达的模式和调控仍然未知。我们的假设是，阴道毛滴虫感染的上皮细胞是皮肤屏障中的主要效应细胞。这些细胞充当 TLR 基因表达的中央调节器，从而通过增加趋化因子和促炎细胞因子的释放来加速屏障功能障碍的过程。为了检验这一假设，对 TLR、白细胞介素 (IL)-8 和肿瘤坏死因子 (TNF)-α 进行了 RT-PCR。观察到阴道毛滴虫对 HeLa 细胞的刺激会上调 TLR2、4 和 9 mRNA 以及 IL-8 和 TNF-α 的表达。为了进一步阐明这些上调刺激引发的屏障破坏的分子机制，我们使用特定抑制剂检查了 HeLa 细胞中细胞外信号调节激酶 (ERK)、p38 丝裂原激活蛋白激酶 (MAPK) 和核因子 (NF)-κ B 激活的概况。有趣的是，用 p38 MAPK 抑制剂 SB203580 预处理 HeLa 细胞可以抑制阴道毛滴虫诱导的 TLR2、4 和 9 mRNA 表达上调。相比之下，抑制 ERK 或 NF-κ B 激活未能分别阻断阴道毛滴虫诱导的 TLR9 mRNA 表达或 TLR2 和 TLR4 mRNA 表达的上调。此外，用 SB203580 预处理可减少阴道毛滴虫引起的上皮源性 IL-8 和 TNF-α 释放。我们的结果表明，粘膜皮肤屏障的阴道毛滴虫感染可以通过上皮细胞中的 p38 MAPK 信号通路上调 TLR2、4 和 9 基因表达。然后，该过程导致 p38 MAPK 依赖性 IL-8 和 TNF-α 从上皮释放的调节。
Toll-like receptors (TLRs) are pattern recognition receptors (PRRs) that recognize conserved pathogen-associated molecular patterns (PAMPs) synthesized by micro-organisms. Despite the essential requirement for TLRs in prokaryotic infection, the pattern and regulation of TLR gene expression by Trichomonas vaginalis in the mucocutaneous barrier are still unknown. Our hypothesis is that T. vaginalis-infected epithelial cells are major effector cells in the skin barrier. These cells function as a central regulator of TLR gene expression, thus accelerating the process of barrier dysfunction via increased release of chemokines and proinflammatory cytokines. To test this hypothesis, RT-PCR was performed on TLRs, interleukin (IL)-8 and tumour necrosis factor (TNF)-alpha. Stimulation of HeLa cells by T. vaginalis was observed to up-regulate TLR2, 4 and 9 mRNA expression as well as that of IL-8 and TNF-alpha. To further clarify the molecular mechanism of barrier devastation triggered by these up-regulatory stimuli, we examined the profiles of extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-kappa B activation in HeLa cells using specific inhibitors. Interestingly, pretreatment of HeLa cells with the p38 MAPK inhibitor SB203580 demonstrated inhibition of T. vaginalis-induced up-regulation of TLR2, 4, and 9 mRNA expression. By contrast, inhibition of ERK or NF-kappa B activation failed to block T. vaginalis-induced up-regulation of TLR9 mRNA expression or TLR2 and TLR4 mRNA expression, respectively. In addition, pretreatment with SB203580 reduced epithelium-derived IL-8 and TNF-alpha release evoked by T. vaginalis. Our results show that T. vaginalis infection of the mucocutaneous barrier could up-regulate TLR2, 4 and 9 gene expression via the p38 MAPK signalling pathway in epithelial cells; this process then leads to modulation of p38 MAPK-dependent IL-8 and TNF-alpha release from the epithelium.