Tumor necrosis factor-alpha induces transforming growth factor-beta1 expression in lung fibroblasts through the extracellular signal-regulated kinase pathway.
Tumor necrosis factor-alpha induces transforming growth factor-beta1 expression in lung fibroblasts through the extracellular signal-regulated kinase pathway.
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发表时间：
2005
影响因子：
6.4
通讯作者：
D. Sullivan;Marybeth Ferris;D. Pociask;A. Brody
中科院分区：
文献类型：
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作者：
D. Sullivan;Marybeth Ferris;D. Pociask;A. Brody
转化生长因子(TGF)-β(1)和肿瘤坏死因子(TNF)-α的高表达被认为在肺纤维化的发生发展中起重要作用。我们最近报道，在原代小鼠肺成纤维细胞(MLF)中，肿瘤坏死因子-α上调了转化生长因子-β(1)的表达，成纤维细胞是纤维化形成的关键细胞群。在本研究中，我们研究了在原代MLF和瑞士3T3成纤维细胞系中参与TNF-α上调转化生长因子-β(1)的信号转导途径。用酶联免疫吸附试验检测，用肿瘤坏死因子-α处理成纤维细胞后，转化生长因子-β(1)蛋白显著增加。在蛋白质增加之前，通过定量、实时、逆转录聚合酶链式反应检测到转化生长因子-β(1)mRNA增加了200-400%。Western印迹分析显示，肿瘤坏死因子-α激活了细胞外信号调节激酶(ERK)，ERK特异性丝裂原活化蛋白激酶通路的抑制剂(PD98059或U0126)阻断了肿瘤坏死因子-α诱导的转化生长因子-β(1)基因和蛋白的表达。信使核糖核酸稳定性实验表明，在未刺激的细胞中，肿瘤坏死因子-α使转化生长因子-β(1)信使核糖核酸的半衰期从约15小时延长到24小时以上。在瑞士3T3成纤维细胞中，选择性磷酸化ERK的结构性活性MEK1的表达足以稳定转化生长因子-β(1)mRNA。这些结果表明，肿瘤坏死因子-α激活ERK特异的丝裂原激活蛋白激酶途径，导致成纤维细胞中转化生长因子-β(1)的产生增加，主要是通过转录后机制，包括稳定转化生长因子-β(1)转录本。
Increased expression of transforming growth factor (TGF)-beta(1) and tumor necrosis factor (TNF)-alpha are thought to play important roles in the development of pulmonary fibrosis. We recently reported that TNF-alpha upregulates TGF-beta(1) expression in primary mouse lung fibroblasts (MLFs), a key cell population in fibrogenesis. In the present study, we have investigated signal transduction pathways involved in TNF-alpha upregulation of TGF-beta(1) in both primary MLFs and the Swiss 3T3 fibroblast cell line. Treatment of fibroblasts with TNF-alpha resulted in a significant increase in TGF-beta(1) protein as measured by ELISA. The increase in protein was preceded by a 200-400% increase in TGF-beta(1) mRNA detected by quantitative, real-time, reverse transcriptase-polymerase chain reaction. Western blot analysis showed that TNF-alpha activated the extracellular signal-regulated kinase (ERK), and inhibitors of the ERK-specific mitogen-activated protein kinase pathway (PD98059 or U0126) blocked TNF-alpha induction of TGF-beta(1) mRNA and protein. mRNA stability experiments showed that TNF-alpha increased the half-life of TGF-beta(1) mRNA to more than 24 h compared with approximately 15 h in unstimulated cells. Expression of constitutively active MEK1 that selectively phosphorylates ERK was sufficient for TGF-beta(1) mRNA stabilization in Swiss 3T3 fibroblasts. These results indicate that TNF-alpha activates the ERK-specific mitogen-activated protein kinase pathway leading to increased TGF-beta(1) production in fibroblasts, primarily via a post-transcriptional mechanism that involves stabilization of the TGF-beta(1) transcript.