Meis2-Shox2转录复合物作用于上腭间充质细胞调控上腭发育的机制研究

Cleft palate is one of the most common birth defects in craniofacial region. It’s accepted that transcription factors play essential roles in the palatogenesis. Recently, researchers have noticed MEIS2 is highly associated with the occurrence of cleft palate in humans. However, the underlying transcription mechanism of MEIS2 in the developing palate is still unclear. We previously found the specific deficiency of Meis2 in palatal mesenchymal cells results in complete cleft palate in mice. Based on high-thorough sequencing data and the bioinformatic analysis, we hereby put forward the new hypothesis: The transcription factor, Meis2 interacts to Shox2 and form the transcription complex to establish tissue specific chromatin landscape to regulate gene expression in the developing palate. In this study, we will employ approaches including genetics, molecular biology, biochemistry, RNA-Seq, ATAC-Seq, ChIP-Seq and bioinformatics to systemically interrogate how Meis2 and Shox2 interacts and how to coordinate palate-specific gene expression during the development of palate in mice. The obtained results of this application will provide insights for understanding the palate development and provide solid foundation for the future precise prevention and treatment of cleft palate.

腭裂是最常见的颅颌面出生缺陷之一。已有大量研究证实转录因子对上腭发育具有重要的调控作用。最新研究发现MEIS2基因突变与人类腭裂密切相关但机制不明。本研究前期在小鼠颅颌面部间充质细胞中敲除Meis2后得到与临床一致的腭裂表型，并基于多种高通量测序数据的生物信息学分析，提出科学假说：Meis2作为上腭发育过程中的核心转录因子，与Shox2共结合到基因组上的特定位点，精确调控上腭间充质中上腭发育特有基因的时空表达，从而调控小鼠的上腭发育。本项目将首先采用多种蛋白互作研究技术与基因修饰小鼠探究Meis2和Shox2的相互作用关系，并利用RNA-Seq、ChIP-Seq和ATAC-Seq精确筛选出两者在在全基因组水平共结合的特定位点以及共同直接调控的基因，再进行相关验证。本项目的研究结果有望阐明Meis2-Shox2转录复合物调控上腭发育的分子机制，有助于为腭裂的精准防治奠定重要的理论基础。

大量研究表明转录因子对上腭发育具有重要的调控作用，课题组立足前期研究基础与国内外进展，提出Meis2作为上腭发育过程中的核心转录因子，与Shox2共结合到基因组上的特定位点，精确调控上腭间充质中上腭发育特有基因的时空表达，从而调控小鼠的上腭发育。本项目利用多种转基因小鼠，联合应用蛋白互作研究技术、高通量测序技术和生物信息学分析，研究发现（1）Meis2和Shox2在上腭间充质中具有相互作用关系，且均会对上腭发育尤其是硬腭成骨分化起调控作用；（2）Meis2和Shox2在全基因组水平具有共同结合位点，并直接参与调控下游成骨分化相关基因；（3）Meis2在细胞的成骨向分化潜能中起关键性调控作用，为硬腭的骨发生设定了基态。本项目研究结果系统揭示了Meis2-Shox2转录复合物调控上腭成骨分化的分子机制，有助于为腭裂的精准防治奠定重要的理论基础。