RhoA对牙髓干细胞迁移过程中干性维持的调控机制研究

It is a key precondition for correct tissue repair at the injury sites to maintain cell stemness while directed migrating. The previous study made by the applicant group showed that RhoA had an important role in migration of dental pulp stem cells (DPSCs) and enhanced Oct4 expression. The applicant hereby put forward a new idea that migration and maintenance of stemness steady synergistically regulate dental pulp repair. The project applys a combination of confocal scanning laser microscope, genomics technology, immune co-precipitation technology, gene recombination technology with in situ tracer technique to solve following problems: (1) Whether a synergic relationship presents in DPSC migration and maintenance of stemness steady; (2) Whether RhoA makes a significant role in maintaining stemness steady during migration process; (3) The cross-talk and key signal nodes involve in regulatory pathway of DPSC migration-stemness maintenance. Research on above problems contributes to clarify the formation mechanism of pulp-dentin complex, to coordinate relevance of migration, stemness steady, and differentiation in early repair process, and to pursue the new valid targets for dentin regeneration. The work has significant theory meanings and broad application outlooks.

干细胞在向损伤部位定向迁移的过程中始终维持其自身干性稳定是组织成功修复的重要前提条件之一。申请者领导的课题组前期研究发现：RhoA对牙髓干细胞的迁移具有重要调控作用，同时发现其干性维持分子Oct4表达上调。据此，申请者首次提出牙髓干细胞的迁移与干性稳定维持呈正向协同关系且受到RhoA信号分子调控的假说。本项目联合应用激光共聚焦显微镜、差异基因组学、免疫共沉淀、基因重组、原位示踪等技术研究（1）牙髓干细胞的迁移与干性稳定维持是否具有正向协同关系；（2）RhoA是否对牙髓干细胞迁移过程中的干性稳定具有调控作用；（3）牙髓干细胞迁移-干性稳定调控通路的交互对话及其关键信号节点是什么。对以上问题的研究将有助于阐明牙髓-牙本质复合体修复的分子机制，有望从修复早期协调迁移、干性稳定、分化等生物学行为入手，为牙本质再生提供新策略，具有重要的理论意义和广阔的应用前景。

干细胞在向损伤部位定向迁移的过程中始终维持其自身干性稳定是组织成功修复的重要前提条件之一。课题组立足前期研究基础及国内外进展，提出牙髓干细胞的迁移与干性稳定维持呈正向协同关系且受到RhoA信号分子调控的假说。本项目联合应用细胞、组化、分子生物学等技术，研究发现（1）牙髓干细胞迁移与迁移过程中的干性维持间存在正向协同效应，该过程接受Oct4蛋白的调控；（2）Oct4介导RhoA参与调控牙髓干细胞迁移过程中的干性维持；（3）Oct4与β-catenin间的相互作用在调控迁移牙髓干细胞干性维持及分化中发挥重要作用，Oct4、β-catenin的时空表达及相互作用关系可能是解锁迁移牙髓干细胞干性维持及分化调控机制的钥匙。（4）牙髓干细胞的干性维持依赖糖酵解途径的活化；研究牙髓干细胞迁移过程中干性维持的分子机制，有望从牙髓损伤修复早期入手，通过协调迁移、干性稳定、分化三者间关系，使牙髓干细胞可迅速迁移至损伤位点进行修复，具有重要的理论意义和广阔的应用前景。