Zhu Shuyu, Chen Rongkun, Zhang Shu, Wang Zhiya, Meng Xueyuan, Ling Peng, Zhou Jing, Xie Zhigang
Dept. of Oral Implantology, the Affiliated Stomatology Hospital of Kunming Medical University, Kunming, China; Yunnan Key Laboratory of Stomatology, School of Stomatology, Kunming Medical University, Kunming, China.
Yunnan Key Laboratory of Stomatology, School of Stomatology, Kunming Medical University, Kunming, China; Dept. of Periodontology, the Affiliated Stomatology Hospital of Kunming Medical University, Kunming, China.
Int Dent J. 2025 Sep 3;75(6):103853. doi: 10.1016/j.identj.2025.103853.
Demineralised dentin matrix (DDM) is an effective scaffold material for bone tissue engineering. However, the osteoimmunological mechanism of DDM remains unexplored. Th17/Treg cell balance has been noticed as a crucial factor in bone regeneration. The aim of this research is to elucidate the influence of DDM on the balance of Th17/Treg and its underlying molecular mechanisms.
The study examined DDM's effects on Th17/Treg cell balance by co-incubating DDM extract with peripheral blood mononuclear cells (PBMCs). Transcriptomics and bioinformatics identified DDM-related differentially expressed genes. A naïve CD4⁺ T cell-bone marrow-derived mesenchymal stem cells (BMSCs) co-culture model assessed DDM's immunomodulatory effects on Th17/Treg differentiation and their impact on BMSC viability and osteogenic differentiation. In vivo, a rabbit mandibular defect model with DDM implantation evaluated bone repair and Th17/Treg regulation.
DDM promoted Treg cell differentiation in PBMCs and increased anti-inflammatory cytokines. Transcriptomic analysis shows that indoleamine 2,3-dioxygenase 1 (IDO1) is a key regulator of Th17/Treg balance. In naïve CD4⁺ T cells, DDM enhanced Treg differentiation, which was blocked by IDO1 inhibition. This immunomodulation improved BMSCs viability and osteogenic differentiation which was attenuated by IDO1 inhibition. Co-culture with naïve CD4⁺ T cells further amplified DDM's pro-osteogenic effects. In rabbit mandibular defects, DDM enhanced bone repair and was suppressed with IDO1 inhibition.
This study demonstrates that DDM regulates the Th17/Treg cell balance by promoting Treg cell differentiation through IDO1 upregulation, with minimal impact on Th17 cells. This immunomodulatory mechanism is a key factor underlying DDM's significant role in bone repair.
脱矿牙本质基质（DDM）是骨组织工程中一种有效的支架材料。然而，DDM的骨免疫机制仍未被探索。Th17/Treg细胞平衡已被视为骨再生的关键因素。本研究的目的是阐明DDM对Th17/Treg平衡的影响及其潜在分子机制。
本研究通过将DDM提取物与外周血单核细胞（PBMC）共孵育，研究DDM对Th17/Treg细胞平衡的影响。转录组学和生物信息学鉴定了与DDM相关的差异表达基因。一个幼稚CD4⁺T细胞-骨髓间充质干细胞（BMSC）共培养模型评估了DDM对Th17/Treg分化的免疫调节作用及其对BMSC活力和成骨分化的影响。在体内，一个植入DDM的兔下颌骨缺损模型评估了骨修复和Th17/Treg调节情况。
DDM促进PBMC中Treg细胞分化并增加抗炎细胞因子。转录组分析表明，吲哚胺2,3-双加氧酶1（IDO1）是Th17/Treg平衡的关键调节因子。在幼稚CD4⁺T细胞中，DDM增强Treg分化，而IDO1抑制可阻断这种分化。这种免疫调节改善了BMSC活力和成骨分化，而IDO1抑制可减弱这种作用。与幼稚CD4⁺T细胞共培养进一步放大了DDM的促骨生成作用。在兔下颌骨缺损中，DDM增强骨修复，而IDO1抑制可抑制这种作用。
本研究表明，DDM通过上调IDO1促进Treg细胞分化来调节Th17/Treg细胞平衡，对Th17细胞影响最小。这种免疫调节机制是DDM在骨修复中发挥重要作用的关键因素。
