lncRNA-G018548结合PTBP1蛋白调控Smad4可变剪接促进人牙髓干细胞成牙本质向分化的机制研究

牙髓干细胞（hDPSCs）成牙本质向分化形成修复性牙本质，是牙髓损伤修复的关键。长链非编码RNA（lncRNA）在间充质干细胞的多向分化过程中发挥关键作用，但其与蛋白结合调控hDPSCs成牙本质向分化尚无报道。申请人预实验发现hDPSCs成牙本质向分化过程中lncRNA-G018548表达上调，且细胞实验证实其促进hDPSCs成牙本质向分化；生物信息学预测及RIP实验证实G018548与蛋白PTBP1结合；RNA-seq筛选出二者共同差异表达的靶基因Smad4，且TGF-β通路显著富集；DEX-seq分析表明Smad4在过表达G018548和过表达PTBP1的hDPSCs中发生可变剪接。本项目将在前期研究基础上，深入探讨G018548与蛋白PTBP1结合后调控Smad4可变剪接进而促进hDPSCs成牙本质向分化具体作用机制，并结合体内模型进行验证，为牙本质再生及活髓保存提供新思路。

Human dental pulp stem cells (hDPSCs) differentiate into dentin to form restorative dentin, which is the key to repair dental pulp injury. Long-chain non-coding RNA(lncRNA) plays a key role in the multi-directional differentiation of mesenchymal stem cells, but it has not been reported that its combination with protein regulates the odontoblast differentiation of hDPSCs. The applicant's pre-experiment found that the expression of lncRNA-G018548 was up-regulated during the odontoblast differentiation of hDPSCs, and cell experiments confirmed that it promoted the odontoblast differentiation of hDPSCs. Bioinformatics prediction and RIP experiments confirmed that G018548 combined with PTBP1. RNA-seq screened out the target gene Smad4 which was differentially expressed, and the TGF-β pathway was significantly enriched. DEX-seq analysis showed that Smad4 had changed alternative splicing in hDPSCs overexpressing G018548 and PTBP1. On the basis of previous studies, this project will deeply explore the specific mechanism of regulating Smad4 alternative splicing after the combination of G018548 and protein PTBP1, and then promote the odontogenic differentiation of hDPSCs, and verify it with the in vivo model, providing new ideas for dentin regeneration and vital pulp preservation.