Proteomic analysis of CTGF-activated lung fibroblasts: identification of IQGAP1 as a key player in lung fibroblast migration
Proteomic analysis of CTGF-activated lung fibroblasts: identification of IQGAP1 as a key player in lung fibroblast migration
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DOI：
10.1152/ajplung.00530.2007
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发表时间：
2008-10-01
影响因子：
4.9
通讯作者：
Silver, Richard M.
中科院分区：
文献类型：
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作者：
Bogatkevich, Galina S.;Ludwicka-Bradley, Anna;Silver, Richard M.
Bogatkevich GS，Ludwicka-Bradley A，Singleton CB，Bethard JR，银RM。CTGF激活的肺成纤维细胞的蛋白质组学分析：IQGAP 1作为肺成纤维细胞迁移中的关键参与者的鉴定。美国生理学杂志肺细胞分子生理学295：L 603-L 611，2008年。首次发表于2008年8月1日; doi：10.1152/ajplung.00530.2007。结缔组织生长因子（CTGF，CCN 2）在从患有间质性肺病（ILD）和系统性硬化症（SSc，硬皮病）的患者分离的肺成纤维细胞中过表达，并且被认为是纤维化的分子标志物。为了了解CTGF升高的意义，我们研究了肺成纤维细胞蛋白质组对CTGF过表达的反应。使用二维凝胶电泳，然后在凝胶蛋白水解消化和质谱分析，我们确定了13个蛋白质受CTGF。已知几种CTGF诱导的蛋白质，如前α（I）胶原蛋白和细胞骨架蛋白黏着斑蛋白、膜突蛋白和埃兹蛋白在肺纤维化中升高，而13种蛋白质中的9种尚未在肺纤维化中研究，因此是可能在ILD中具有重要作用的新型CTGF应答分子。我们的研究表明，一种新的CTGF诱导的蛋白质，含有GT3活化蛋白（IQGAP）1的IQ基序，在从患有ILD的硬皮病患者分离的肺成纤维细胞中升高。IQGAP 1是一种支架蛋白，在调节内皮细胞和上皮细胞的迁移中发挥关键作用。用CTGF处理的硬皮病肺成纤维细胞和正常肺成纤维细胞在伤口愈合测定中表现出增加的迁移速率。用小干扰RNA消除IQGAP 1表达可抑制肺成纤维细胞中CTGF诱导的迁移和MAPK ERK 1/2磷酸化。MAPK抑制剂U 0126降低CTGF诱导的细胞迁移，并且不干扰CTGF诱导的IQGAP 1表达，表明MAPK途径在IQGAP 1的下游。这些发现进一步暗示了CTGF在肺组织修复和纤维化中的重要性，并提出CTGF诱导的肺成纤维细胞向受损组织的迁移是通过IQGAP 1和MAPK信号传导途径介导的。
Bogatkevich GS, Ludwicka-Bradley A, Singleton CB, Bethard JR, Silver RM. Proteomic analysis of CTGF- activated lung fibroblasts: identification of IQGAP1 as a key player in lung fibroblast migration. Am J Physiol Lung Cell Mol Physiol 295: L603-L611, 2008. First published August 1, 2008; doi: 10.1152/ajplung.00530.2007.-Connective tissue growth factor ( CTGF, CCN2) is overexpressed in lung fibroblasts isolated from patients with interstitial lung disease (ILD) and systemic sclerosis (SSc, scleroderma) and is considered to be a molecular marker of fibrosis. To understand the significance of elevated CTGF, we investigated the changes in lung fibroblast proteome in response to CTGF overexpression. Using 2-dimensional gel electrophoresis followed by in-gel proteolytic digestion and mass spectrometric analysis, we identified 13 proteins affected by CTGF. Several of the CTGF- induced proteins, such as pro-alpha ( I) collagen and cytoskeletal proteins vinculin, moesin, and ezrin, are known to be elevated in pulmonary fibrosis, whereas 9 of 13 proteins have not been studied in pulmonary fibrosis and are, therefore, novel CTGF- responsive molecules that may have important roles in ILD. Our study demonstrates that 1 of the novel CTGF- induced proteins, IQ motif containing GTPase activating protein ( IQGAP) 1, is elevated in lung fibroblasts isolated from scleroderma patients with ILD. IQGAP1 is a scaffold protein that plays a pivotal role in regulating migration of endothelial and epithelial cells. Scleroderma lung fibroblasts and normal lung fibroblasts treated with CTGF demonstrated increased rate of migration in a wound healing assay. Depletion of IQGAP1 expression by small interfering RNA inhibited CTGF- induced migration and MAPK ERK1/2 phosphorylation in lung fibroblasts. MAPK inhibitor U0126 decreased CTGF- induced cell migration and did not interfere with CTGF- induced IQGAP1 expression, suggesting that MAPK pathway is downstream of IQGAP1. These findings further implicate the importance of CTGF in lung tissue repair and fibrosis and propose that CTGF- induced migration of lung fibroblasts to the damaged tissue is mediated via IQGAP1 and MAPK signaling pathways.