Xia Yu, Jiang Hao, Wang Chen, Liu Zhen, Gao Hui, Yu Ji-Feng, Yang Nan, Liang Li
Department of Stomatology, Eighth Medical Center of Chinese PLA General Hospital, No. 17, Heishanhu Road, Haidian District, Beijing, 100091, China.
Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 Nanlishi Road, Xicheng District, Beijing, 100045, China.
BMC Oral Health. 2025 Sep 26;25(1):1465. doi: 10.1186/s12903-025-06770-0.
Regulatory T (Treg) cells are essential for maintaining immune tolerance and have been implicated in tissue regeneration; however, their role in periodontal regeneration remains poorly understood. This study aimed to elucidate the effect of Treg cell-derived exosomes (Treg-Exos), particularly those carrying microRNA-21 (miR-21), on the osteogenic differentiation of periodontal ligament stem cells (PDLSCs) and periodontal tissue regeneration.
After co-culturing Treg cells or Treg-Exos with PDLSCs respectively in vitro, the osteogenic differentiation of treated PDLSCs was assessed through Alkaline phosphatase (ALP) activity, Alizarin Red staining, and the expression of osteogenic markers runt-related transcription factor 2 (Runx-2) and Osterix. The functional role of miR-21 in Treg-Exos was assessed via gain- and loss-of-function experiments, involving transfection of Treg cells with miR-21 mimics or inhibitors. In vivo, a mice periodontal defect model was established via silk ligation and Porphyromonas gingivalis inoculation. Subsequently, Treg-Exos were locally administered into defects to assess their potential in promoting periodontal tissue regeneration. The regenerative efficacy was evaluated using micro-CT and histological analysis.
Treg cell levels were significantly elevated in periodontitis patients compared to healthy controls. Both Treg cells and Treg-Exos markedly promoted the osteogenic differentiation of PDLSCs in vitro, as evidenced by increased ALP activity, enhanced mineralization, and upregulated Runx-2/Osterix expression. Exosomes derived from miR-21-overexpressing Treg cells further promoted PDLSC osteogenesis, whereas exosomes with miR-21 knockdown exhibited an inhibitory effect. In vivo, Treg-Exos injection alleviated periodontal damage and improved tissue morphology compared to PBS controls, as demonstrated by micro-CT and histological analyses.
Treg cell-derived exosomal miR-21 promotes the osteogenic differentiation of PDLSCs, enhancing periodontal tissue regeneration in vivo, suggesting that Treg cells and their exosomal miR-21 may serve as promising therapeutic targets for periodontitis.
调节性T（Treg）细胞对于维持免疫耐受至关重要，并与组织再生有关；然而，它们在牙周再生中的作用仍知之甚少。本研究旨在阐明Treg细胞衍生的外泌体（Treg-Exos），特别是携带微小RNA-21（miR-21）的外泌体，对牙周膜干细胞（PDLSCs）成骨分化和牙周组织再生的影响。
分别在体外将Treg细胞或Treg-Exos与PDLSCs共培养后，通过碱性磷酸酶（ALP）活性、茜素红染色以及成骨标志物 runt相关转录因子2（Runx-2）和osterix的表达来评估处理后PDLSCs的成骨分化。通过功能获得和功能丧失实验评估miR-21在Treg-Exos中的作用，包括用miR-21模拟物或抑制剂转染Treg细胞。在体内，通过丝线结扎和牙龈卟啉单胞菌接种建立小鼠牙周缺损模型。随后，将Treg-Exos局部注入缺损处，以评估其促进牙周组织再生的潜力。使用微型计算机断层扫描（micro-CT）和组织学分析评估再生效果。
与健康对照相比，牙周炎患者的Treg细胞水平显著升高。Treg细胞和Treg-Exos在体外均显著促进PDLSCs的成骨分化，表现为ALP活性增加、矿化增强以及Runx-2/Osterix表达上调。来自miR-21过表达Treg细胞的外泌体进一步促进PDLSC成骨，而miR-21敲低的外泌体则表现出抑制作用。在体内，与磷酸盐缓冲液（PBS）对照相比，微型计算机断层扫描和组织学分析表明，注射Treg-Exos可减轻牙周损伤并改善组织形态。
Treg细胞衍生的外泌体miR-21促进PDLSCs的成骨分化，增强体内牙周组织再生，表明Treg细胞及其外泌体miR-21可能是牙周炎有前景的治疗靶点。
