Single-cell atlas of human gingival tissues during healing process after ultrasonic scaling and root planing

Objective: To evaluate the composition and function of mural cell populations in human gingival tissues Results: Two mural cell clusters, RGS5+THY1+ and ACTA2+MYH11+ subpopulations, were identified and confirmed by histological staining and cross-validation with three different single-cell RNA sequencing datasets in the GEO database. RGS5+THY1+ cluster in perivascular areas possessed cellular protrusions and exhibited immunomodulatory and synthetic phenotypes. In contrast, the ACTA2+MYH11+ cluster strictly distributed around vessel walls was characterized by a contractile phenotype. Mural cells closely interacted with endothelial cells through PDGF and NOTCH3 signaling. Mural cell loss was detected in the v_i group and in hopeless periodontal teeth, which might be caused by tumor necrosis factor-alpha induced apoptosis. Overall design: A cross-sectional study was conducted on seven periodontitis (stage ?) patients. Gingival tissues were collected two months after scaling and root planing and divided into 3 groups: 1, h_h group (horizontal bone resorption, residual pocket depth =3 mm); 2, v_h group (vertical bone resorption >4 mm, residual pocket depth =3 mm); 3, v_i group (vertical bone resorption >4 mm, residual pocket depth =6 mm). Single-cell RNA sequencing (10X genomics) and subsequent bioinformatics analysis were performed. Protein expression of selected genes was confirmed by histological staining.

研究目标：评估人牙龈组织中壁细胞群的组成与功能。
研究结果：本研究鉴定出两类壁细胞簇——RGS5+THY1+与ACTA2+MYH11+亚群，并通过组织染色以及GEO数据库（Gene Expression Omnibus）中3个不同的单细胞RNA测序（single-cell RNA sequencing）数据集开展交叉验证，最终确认了上述亚群的存在。其中，RGS5+THY1+簇定位于血管周围区域，具有细胞突起结构，呈现免疫调节与合成表型；与之相对，严格分布于血管壁周围的ACTA2+MYH11+簇则以收缩表型为特征。壁细胞可通过血小板衍生生长因子（PDGF）与NOTCH3信号通路与内皮细胞实现紧密互作。在v_i组以及无望保留的牙周患牙中可检测到壁细胞丢失现象，该现象可能由肿瘤坏死因子-α诱导的细胞凋亡所引发。
整体研究设计：本研究为横断面研究，共纳入7名牙周炎（分期不详）患者。于刮治与根面平整术后2个月采集牙龈组织，并将其分为3组：1. h_h组（水平型骨吸收，残余牙周袋深度=3 mm）；2. v_h组（垂直型骨吸收>4 mm，残余牙周袋深度=3 mm）；3. v_i组（垂直型骨吸收>4 mm，残余牙周袋深度=6 mm）。随后开展单细胞RNA测序（10X Genomics）及后续生物信息学分析，并通过组织染色验证了选定基因的蛋白表达水平。