Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
Mol Cell Biol. 2014 Apr;34(8):1500-11. doi: 10.1128/MCB.01357-13. Epub 2014 Feb 10.
The transcriptional cofactor ANKRD1 is sharply induced during wound repair, and its overexpression enhances healing. We recently found that global deletion of murine Ankrd1 impairs wound contraction and enhances necrosis of ischemic wounds. A quantitative PCR array of Ankrd1(-/-) (KO) fibroblasts indicated that ANKRD1 regulates MMP genes. Yeast two-hybrid and coimmunoprecipitation analyses associated ANKRD1 with nucleolin, which represses AP-1 activation of MMP13. Ankrd1 deletion enhanced both basal and phorbol 12-myristate 13-acetate (PMA)-induced MMP13 promoter activity; conversely, Ankrd1 overexpression in control cells decreased PMA-induced MMP13 promoter activity. Ankrd1 reconstitution in KO fibroblasts decreased MMP13 mRNA, while Ankrd1 knockdown increased these levels. MMP13 mRNA and protein were elevated in intact skin and wounds of KO versus Ankrd1(fl/fl) (FLOX) mice. Electrophoretic mobility shift assay gel shift patterns suggested that additional transcription factors bind to the MMP13 AP-1 site in the absence of Ankrd1, and this concept was reinforced by chromatin immunoprecipitation analysis as greater binding of c-Jun to the AP-1 site in extracts from FLOX versus KO fibroblasts. We propose that ANKRD1, in association with factors such as nucleolin, represses MMP13 transcription. Ankrd1 deletion additionally relieved MMP10 transcriptional repression. Nuclear ANKRD1 appears to modulate extracellular matrix remodeling by MMPs.
转录共激活因子 ANKRD1 在伤口修复过程中被强烈诱导，其过表达可增强愈合。我们最近发现，小鼠 Ankrd1 的全局缺失会损害伤口收缩并增强缺血性伤口的坏死。ANKRD1(-/-) (KO) 成纤维细胞的定量 PCR 阵列表明 ANKRD1 调节 MMP 基因。酵母双杂交和共免疫沉淀分析将 ANKRD1 与核仁蛋白联系在一起，核仁蛋白抑制 MMP13 的 AP-1 激活。Ankrd1 缺失增强了 MMP13 启动子的基础活性和佛波醇 12-肉豆蔻酸 13-醋酸酯 (PMA)诱导的活性；相反，在对照细胞中过表达 Ankrd1 会降低 PMA 诱导的 MMP13 启动子活性。在 KO 成纤维细胞中重建 Ankrd1 会降低 MMP13 mRNA，而 Ankrd1 敲低会增加这些水平。与 Ankrd1(fl/fl) (FLOX) 小鼠相比，KO 皮肤和伤口中的 MMP13 mRNA 和蛋白升高。电泳迁移率变动分析凝胶迁移模式表明，在缺乏 Ankrd1 的情况下，其他转录因子会结合 MMP13 的 AP-1 位点，而来自 FLOX 与 KO 成纤维细胞提取物的 c-Jun 对 AP-1 位点的结合更多的染色质免疫沉淀分析则强化了这一概念。我们提出，ANKRD1 与核仁蛋白等因子一起，抑制 MMP13 转录。Ankrd1 缺失还解除了对 MMP10 转录的抑制。核内 ANKRD1 似乎通过 MMP 调节细胞外基质重塑。
