miR-21调控牙周膜干细胞成骨分化及组织再生的研究

Dental mesenchymal stem cell-mediated regeneration of tooth and periodontal supporting tissue in swine has provided therapeutic strategies for the replacement of a diseased or damaged tooth. The regulation of tissue regeneration focused on pretranscriptional, transcriptional, translational and posttranslational control. MicroRNA (miRNA) plays a vital role in tissue regeneration at postranscriptional level. In our previous research, we have identified miR-21 as a potential influential factor during the odontoblastic/osteoblastic differentiation of periodontal ligament stem cells (PDLSCs). In this project, we will use both in vitro and in vivo model to study further the effect of miR-21 on the osteogenic differentiation of PDLSCs, predict and identify the target gene of miR-21, and try to elucidate the mechanism by which miR-21 regulates the osteogenic differentiation and tissue regeneration. This study might demonstrate the regulatory mechanism of miR-21 during PDLSCs-mediated tissue regeneration and could provide further evidence for stem cell-mediated tissue regeneration.

牙齿间充质干细胞用于牙齿和牙周组织再生在大型动物上已取得很大进展，但组织再生的基因调控研究则主要集中在转录前调控、转录调控、翻译调控和翻译后调控。近来发现了以microRNA（miRNA）为代表的转录后调控，miRNA在干细胞分化组织再生时起着重要作用。本课题在前期筛选出牙周膜干细胞成骨向分化中表现突出的miR-21基础上，进一步研究miR-21对牙周膜干细胞成骨向分化的影响；预测验证其靶基因，研究miR-21调控牙周膜干细胞成骨分化的机制；并将pGenesil-miR-21及pGenesil-si-miR-21转染的牙周膜干细胞回植于小型猪缺牙区牙槽骨内，研究miR-21对组织再生的影响及回植不同阶段miR-21及其靶基因的调控功能。通过本研究有望阐明牙周膜干细胞介导组织再生中miR-21的调控功能，为通过调控牙齿干细胞促进口腔组织再生提供重要理论依据。

牙齿间充质干细胞用于牙齿和牙周组织再生在大型动物上已取得很大进展，但组织再生的基因调控研究则主要集中在转录前调控、转录调控、翻译调控和翻译后调控。近来发现了以microRNA（miRNA）为代表的转录后调控，miRNA在干细胞分化组织再生时起着重要作用。本课题在前期筛选出牙周膜干细胞成骨向分化中表现突出的miR-21基础上，进一步研究miR-21对牙周膜干细胞成骨向分化的影响；成骨向诱导1,3,5,7,10,14天后，miR-21表达下降，成骨诱导过程中，ALP活性及Ca浓度表达增强，成骨相关基因ALP, RUNX2, OSX and BSP表达增高。将miR-21过表达病毒（Lentiviral pre-miR-21-GFP）转染牙周膜干细胞，发现细胞成骨分化减弱，细胞增殖增强。将miR-21抑制病毒（pGC-LV-anti-miR-21-GFP）转染牙周膜干细胞，发现细胞成骨分化增强，细胞增殖减弱。体内实验表明，过表达miR-21抑制成骨，抑制miR-21促进成骨。通过本研究阐明了牙周膜干细胞介导组织再生中miR-21的调控功能，为通过调控牙齿干细胞促进口腔组织再生提供重要理论依据。