转录因子Barx1调控Dlx5介导PDA促正畸牙骨质再生的分子机制

开发有效的促进牙骨质再生策略对于成人正畸治疗具有重要临床意义。申请者前期发现聚多巴胺（PDA）能够有效促进牙骨质再生，促进成牙骨质细胞的分化，并结合RNA seq和Chip seq等高通量方法发掘了潜在的分子机制，提出了如下假说：转录因子Barx1能直接与Dlx5启动子结合并调控Dlx5的转录，介导了PDA促进牙骨质再生的作用。为此设计了本研究，内容如下：首先借助Micro-CT、免疫组化染色等方法，在大鼠正畸牙移动模型中明确PDA对牙骨质再生的作用特点，并检测Barx1、Dlx5的表达趋势；其次分别上调和下调成牙骨质细胞中Barx1表达，进一步明确Barx1在成牙骨质细胞中的作用表型；最后借助Chip qPCR、荧光酶素报告实验、EMSA等手段，明确Barx1与Dlx5启动子结合的准确位点。通过本项目的开展，有望揭示PDA促进正畸牙骨质再生的分子机制，为提升成人正畸效果提供新的思路。

Developing an effective strategy to promote cementum regeneration has important clinical implications for adult orthodontic treatment. Applicants have previously found that polydopamine (PDA) can effectively promote cementum regeneration and enhance the differentiation of cementoblasts. Then the high-throughput methods such as RNA seq and Chip seq were employed to explore the underlying molecular mechanisms. The following hypothesis is proposed: The transcription factor Barx1 binds directly to the Dlx5 promoter and regulates the transcription of Dlx5, mediating the role of PDA in promoting cementum formation. The current research was designed for this purpose. The content of the research was listed as follow: Firstly, micro-CT and immunohistochemical staining were used to identify the effects of PDA on cementum formation in the orthodontic tooth movement model, and the expression of Barx1 and Dlx5 was detected. Then the expression of Barx1 in cementoblasts was up-regulated and down-regulated separately, to further clarify the role of Barx1 in cementoblasts. Finally, the exact binding site between Barx1 and Dlx5 were identified by means of Chip qPCR, fluorescein reporter assay and EMSA. Through the performance of this project, it is expected to reveal the molecular mechanism of PDA to promote orthodontic cementum regeneration, and provide new strategy for improving adult orthodontic effects.