Department of Basic Science of Stomatology, The Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China; Jiangsu Province Key Laboratory of Oral Diseases, Nanjing, China; Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, China.
Department of Pathology and Laboratory Medicine and Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA.
Theranostics. 2022 Jan 1;12(3):1074-1096. doi: 10.7150/thno.65694. eCollection 2022.
Single-cell RNA sequencing (scRNA-seq) enables specific profiling of cell populations at single-cell resolution. The osteoimmunology microenvironment in the occurrence and development of periodontitis remains poorly understood at the single-cell level. In this study, we used single-cell transcriptomics to comprehensively reveal the complexities of the molecular components and differences with counterparts residing in periodontal tissues. We performed scRNA-seq to identify 51248 single cells from healthy controls (n=4), patients with severe chronic periodontitis (n=5), and patients with severe chronic periodontitis after initial periodontal therapy within 1 month (n=3). Uniform manifold approximation and projection (UMAP) were further conducted to explore the cellular composition of periodontal tissues. Pseudotime cell trajectory and RNA velocity analysis, combined with gene enrichment analysis were used to reveal the molecular pathways underlying cell fate decisions. CellPhoneDB were performed to identify ligand-receptor pairs among the major cell types in the osteoimmunology microenvironment of periodontal tissues. A cell atlas of the osteoimmunology microenvironment in periodontal tissues was characterized and included ten major cell types, such as fibroblasts, monocytic cells, endothelial cells, and T and B cells. The enrichment of fibroblasts with high expression of , and was detected in patients with periodontitis compared to healthy individuals. The fractions of mesenchymal stem cells (MSCs), pre-osteoblasts (pre-OBs), and osteoblasts decreased significantly in response to initial periodontal therapy. In addition, MSC-like pericytes could convert their identity into a pre-OB state during inflammatory responses even after initial periodontal therapy confirmed by single-cell trajectory. Moreover, we portrayed the distinct subtypes of monocytic cells and abundant endothelial cells significantly involved in the immune response. The heterogeneity of T and B cells in periodontal tissues was characterized. Finally, we mapped osteoblast/osteoclast differentiation mediators to their source cell populations by identifying ligand-receptor pairs and highlighted the effects of Ephrin-Eph signaling on bone regeneration after initial periodontal therapy. Our analyses uncovered striking spatiotemporal dynamics in gene expression, population composition, and cell-cell interactions during periodontitis progression. These findings provide insights into the cellular and molecular underpinning of periodontal bone regeneration.
单细胞 RNA 测序 (scRNA-seq) 可实现单细胞分辨率下的细胞群体特异性分析。在牙周炎的发生和发展中，骨免疫学微环境在单细胞水平上仍知之甚少。在这项研究中，我们使用单细胞转录组学全面揭示了分子成分的复杂性以及与牙周组织中对应物的差异。我们进行了 scRNA-seq，从健康对照组（n=4）、严重慢性牙周炎患者（n=5）和接受初始牙周治疗后 1 个月内的严重慢性牙周炎患者（n=3）中鉴定了 51248 个单细胞。进一步进行统一流形逼近和投影 (UMAP) 以探索牙周组织的细胞组成。假时间细胞轨迹和 RNA 速度分析，结合基因富集分析，用于揭示细胞命运决定的分子途径。使用 CellPhoneDB 在牙周组织骨免疫学微环境中的主要细胞类型之间鉴定配体-受体对。表征了牙周组织骨免疫学微环境的细胞图谱，包括成纤维细胞、单核细胞、内皮细胞和 T 和 B 细胞等十种主要细胞类型。与健康个体相比，牙周炎患者中高表达 、 和 的成纤维细胞富集。对初始牙周治疗的反应中，间充质干细胞 (MSC)、前成骨细胞 (pre-OB) 和 成骨细胞的分数明显下降。此外，即使在初始牙周治疗确认后，炎症反应期间 MSC 样周细胞也可以将其身份转化为 pre-OB 状态，这一点通过单细胞轨迹得到证实。此外，我们描绘了参与免疫反应的单核细胞和丰富的内皮细胞的明显不同亚型。还对牙周组织中 T 和 B 细胞的异质性进行了描述。最后，通过鉴定配体-受体对，将成骨细胞/破骨细胞分化介质映射到其源细胞群，并强调 Ephrin-Eph 信号对初始牙周治疗后骨再生的影响。我们的分析揭示了牙周炎进展过程中基因表达、群体组成和细胞-细胞相互作用的惊人时空动态。这些发现为牙周骨再生的细胞和分子基础提供了深入了解。
