Notch signaling regulates col1α1 and col1α2 expression in airway fibroblasts
Notch signaling regulates col1α1 and col1α2 expression in airway fibroblasts
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DOI：
10.1177/1535370214538919
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发表时间：
2014-12-01
影响因子：
3.2
通讯作者：
Wang, Ping
中科院分区：
文献类型：
--
作者：
Hu, Mei;Ou-Yang, Hai-Feng;Wang, Ping
上皮下纤维化是哮喘气道重塑的共同病理特征之一。在上皮下纤维化过程中，I型胶原成为最丰富的细胞外蛋白组分。研究表明，Notch信号参与纤维化的进展;然而，Notch信号是否参与调节气道成纤维细胞中I型胶原的表达仍不清楚。本研究的目的是检查Notch信号是否可以调节气道成纤维细胞中I型胶原蛋白的表达，并探索潜在的分子机制。在此，在小鼠L929细胞和人MRC-5细胞中检查Notch信号传导组分的表达。在这些细胞系中上调或下调Notch信号传导后，检查col 1 α 1和col 1 α 2表达。使用基因报告基因测定，定点诱变，和ChIP测定，在小鼠和人的COL 1A 1和COL 1A 2启动子的Hes 1结合位点的作用进行了研究。这项研究表明，Notch信号相关分子（包括Notch 1，Hes 1等）在L929和MRC-5细胞中表达，Notch信号调节两种细胞系中col 1 alpha 1和col 1 alpha 2的表达。此外，Notch胞内结构域的过表达导致COL 1A 1和COL 1A 2启动子的激活，并且定点诱变报告基因测定显示Hes 1蛋白可能增强小鼠和人COL 1A 1和COL 1A 2启动子活性。此外，ChIP测定证实，Hes 1结合到L929和MRC-5细胞中的COL 1A 1和COL 1A 2启动子。因此，有理由认为Notch信号通过Hes 1依赖性机制直接上调COL 1A 1和COL 1A 2启动子活性，这可能成为气道上皮下纤维化药物治疗的一个可能靶点。
Subepithelial fibrosis is one of the common pathological features of asthmatic airway remodeling. During subepithelial fibrosis, type I collagen becomes the most abundant extracellular protein component. Studies have shown that Notch signaling participates in the progression of fibrosis; however, whether Notch signaling is involved in regulating type I collagen expression in airway fibroblasts remains unclear. The aim of the present study was to examine whether Notch signaling can regulate type I collagen expression in airway fibroblasts and to explore the underlying molecular mechanisms. Here, the expression of Notch signaling components was examined in mouse L929 cells and human MRC-5 cells. After upregulating or downregulating Notch signaling in these cell lines, col1 alpha 1 and col1 alpha 2 expression was examined. Using gene reporter assays, site-directed mutagenesis, and ChIP assays, the role of Hes1 binding sites in both the mouse and human COL1A1 and COL1A2 promoters was investigated. This study revealed that Notch signaling-related molecules (including Notch1, Hes1, and others) are expressed in L929 and MRC-5 cells and that Notch signaling regulates the expression of col1 alpha 1 and col1 alpha 2 in both cell lines. Additionally, over-expression of the Notch intracellular domain resulted in activation of the COL1A1 and COL1A2 promoters, and site-directed mutagenesis reporter assays revealed that Hes1 proteins might augment both mouse and human COL1A1 and COL1A2 promoter activity. Furthermore, ChIP assays confirmed that Hes1 binds to the COL1A1 and COL1A2 promoters in both L929 and MRC-5 cells. Therefore, it is reasonable to assume that Notch signaling can directly upregulate COL1A1 and COL1A2 promoter activity through a Hes1-dependent mechanism, which could serve as a possible target for pharmacotherapy of airway subepithelial fibrosis.