Chd4 and associated proteins function as corepressors of Sox9 expression during BMP-2-induced chondrogenesis
Chd4 and associated proteins function as corepressors of Sox9 expression during BMP-2-induced chondrogenesis
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Chd4 和相关蛋白在 BMP-2 诱导的软骨形成过程中充当 Sox9 表达的辅抑制因子
DOI：
10.1002/jbmr.1932
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发表时间：
2013-09-01
影响因子：
6.2
通讯作者：
Pan, Qiuhui
中科院分区：
文献类型：
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作者：
Sun, Fenyong;Yang, Qingyuan;Pan, Qiuhui
小鼠胚胎成纤维细胞（MEFs）在骨形态发生蛋白-2（BMP-2）的作用下分化为功能完整的软骨细胞。然而，BMP-2诱导的软骨形成的综合蛋白质组学方面仍然未知。我们利用定量蛋白质组学分析的基础上同量异位素标签的相对和绝对定量（iTRAQ）和在线2D纳米液相色谱/串联质谱（LC/MS/MS），以确定差异表达的蛋白质在BMP-2诱导MEFs的软骨分化。我们发现了85个下调的蛋白质，独创性途径分析（IPA）揭示了一个蛋白质-蛋白质网络，中心是染色体结构域-解旋酶-DNA结合蛋白4（Chd 4）。染色质免疫沉淀（ChIP）和核酸酶超敏反应分析表明，Chd 4与Hdac 1/2相互作用，与其相关蛋白Kap 1和Cbx 1协同结合在Sox 9启动子的-207/-148处。我们还提供了let-7a靶向Chd 4的3 'UTR以促进MEFs的软骨形成的证据。总之，我们的研究结果表明，BMP-2诱导let-7a的上调，靶向Chd 4，并积极控制MEFs的软骨分化。这些发现阐明了软骨形成分化过程的表观遗传调控，也扩展了对所涉及的细胞内机制的理解。(C)2013年美国骨与矿物质研究学会。
Mouse embryonic fibroblasts (MEFs) differentiate into fully functional chondrocytes in response to bone morphogenetic protein-2 (BMP-2). However, the comprehensive proteomic aspect of BMP-2-induced chondrogenesis remains unknown. We took advantage of quantitative proteomic analysis based on isobaric tag for relative and absolute quantitation (iTRAQ) and on-line 2D nano-liquid chromatography/tandem mass spectrometry (LC/MS/MS) to identify proteins differentially expressed during BMP-2-induced chondrogenic differentiation of MEFs. We found 85 downregulated proteins, and ingenuity pathways analysis (IPA) revealed a protein-protein network with chromodomain-helicase-DNA-binding protein 4 (Chd4) in the center. Chromatin immunoprecipitation (ChIP) and nuclease hypersensitivity assays showed that Chd4, interacting with Hdac1/2, cooperates with its related proteins Kap1 and Cbx1 to bind at -207/-148 of the Sox9 promoter. We also provided evidence that let-7a targets the 3'UTR of Chd4 to promote chondrogenesis of MEFs. Together, our findings indicate that BMP-2 induced the upregulation of let-7a, targeting Chd4 and positively controlling the chondrogenic differentiation of MEFs. These findings illustrate epigenetic regulation of the chondrogenic differentiation process and also expand the understanding of the involved intracellular mechanisms. (C) 2013 American Society for Bone and Mineral Research.