组织特异性增强子调控Sox9在下颌骨精确性时空表达及参与Pierre-Robin综合征发生的机制研究

Pierre-Robin综合征/序列征(PRS)主要表现为小下颌、腭裂与舌后坠。文献报道和课题组前期研究表明，PRS患者存在17q24染色体转位、微缺失、重复或序列突变。相应染色体区域包含调控Sox9在下颌骨特异性表达的增强子，但其与PRS确切关系不清楚。课题组前期发掘了部分Sox9下颌骨组织特异性增强子，建立了Sox9下颌骨组织特异性增强子敲除导致下颌骨发育不足小鼠模型。本项目拟应用Hi-C、4C-Seq等技术，借助模式小鼠和PRS患者诱导多能干细胞等发掘Sox9下颌骨组织特异性增强子并阐明其功能。明确组织特异性增强子调控Sox9在下颌骨精确性时空表达机制。揭示染色体转位、缺失、重复或突变等导致PRS发生的分子、细胞与功能变化,如染色体三维构型及增强子-启动子互作频率改变、增强子与特定转录因子如Dlx2结合强度改变、增强子表观遗传学修饰改变等。相关研究成果有望提高PRS精准诊治水平。

Pierre-Robin syndrome/sequence (PRS) is characterized by mandibular hypoplasia, cleft palate and glossoptosis. References and our previous studies showed that there was translocation, microdeletion, duplication or sequence mutation of 17q24 chromosome in PRS patients. The corresponding chromosomal regions contain enhancers that regulate the specific expression of Sox9 in the mandible, but the exact relationship between them and PRS is unclear. We previously found some mandibular tissue-specific enhancers of Sox9, and established mouse models with mandibular hypoplasia caused by knockout of mandibular tissue-specific enhancer of Sox9. This project tries to find out more mandibular tissue-specific enhancer of Sox9 and clarify its function using Hi-C, 4C-Seq and other technologies with the help of mice model and induced pluripotent stem cells of PRS patients, to clarify the mechanism of tissue-specific enhancer regulating the precise spatiotemporal expression of Sox9 in mandible, and to reveal the molecular, cellular and functional changes in PRS caused by chromosomal translocation, deletion, duplication or mutation, such as the change of chromosome three-dimensional configuration and enhancer-promoter interaction frequency, the change of enhancer binding strength with specific transcription factors such as Dlx2, the change of epigenetic modification in enhancer, etc. The research results are expected to improve the precise diagnosis and treatment level of PRS.