人牙周膜干细胞成骨分化相关环状RNA的表达谱及circFAT1作用和机制的研究

The destruction of periodontal tissue caused by periodontal disease and trauma is the major cause of tooth loss in adults. Thus, to regenerate periodontal tissue is always highlighted in the field of stomatology. Human periodontal ligament stem cells (hPDLSCs) are the ideal seed cells for periodontal tissue regeneration, and the osteogenic potential of hPDLSCs is the basis of periodontal tissue repair and regeneration. Noncoding RNA has been shown to play an important role in regulating the osteogenic differentiation of hPDLSCs, however, the role of circular RNA (circRNA) was still unknown. In this study, we investigated the circRNA profiles during the osteogenic differentiation of hPDLSCs, and found that circRNA displayed stage-specific expression. Moreover, we performed bioinformatic analysis of circFAT1, one of the differentially expressed genes, and the results suggested that circFAT1 inhibited the osteogenic differentiation of hPDLSCs by binding miR-181b, miR-34a, miR-3960, and miR-376c. This study is conducive to determine the role of circFAT1 in regulating the osteogenic differentiation of hPDLSCs in vitro and in vivo, and to clarify the underlying competitive endogenous mechanism, shedding light on the enhancement of periodontal tissue regeneration by targeting circFAT1.

牙周炎和外伤等导致的牙周组织破坏是成年人失牙的主要原因，因而实现牙周组织再生是口腔医学研究的要务之一 。人牙周膜干细胞(hPDLSCs)是牙周组织再生理想的种子细胞，其成骨分化能力是牙周组织再生的基础。非编码RNA对hPDLSCs成骨分化具有重要调控作用，但环状RNA(circRNA)在其间的作用尚无报道。本项目前期检测了hPDLSCs 成骨分化相关的 circRNA 表达谱，并针对特定的差异表达基因circFAT1进行了生物信息学研究，结果提示circFAT1可能通过结合 miR-181b、miR-34a、miR-3960 和 miR-376c，抑制hPDLSCs分化为成骨细胞。本研究拟通过体外细胞学、分子生物学和动物体内实验，进一步明确circFAT1对hPDLSCs成骨分化的作用，阐明其竞争性内源作用机制，试图以circFAT1为靶点促进hPDLSCs成骨分化以及牙周骨组织再生。

人牙周膜干细胞(human periodontal ligament stem cells, hPDLSCs)具有多向分化潜能，是修复牙周组织较为理想的种子细胞。针对hPDLSCs成骨分化调控机制的研究有助于优化基于干细胞的牙周组织再生治疗。鉴于非编码RNA对间充质干细胞成骨分化的重要调控作用，本项目通过高通量测序的技术手段检测hPDLSCs成骨分化相关的全转录组，筛选了具有重要调控作用的circRNA和lncRNA，结果显示circFAT1、CDR1as、GAS5、MIR31HG、MEG3、FER1L4、MIR22HG等均在成骨细胞分化中具有潜在的调控作用。本项目进一步构建了circRNA-miRNA-mRNA以及lncRNA-mRNA的调控网络，并针对环状RNA circFAT1对hPDLSCs成骨分化的作用进行研究。体内和体外实验均显示敲低circFAT1能够促进hPDLSCs向成骨细胞分化，且circFAT1对NF-κB信号通路和miR-29b表达具有调控作用。以上研究结果对于全面认识非编码RNA在成骨细胞分化过程中的功能具有促进作用，完善了现有成骨细胞分化的调控网络，为临床利用干细胞进行牙周组织再生治疗提供依据。