【摘要】 目的 牙周炎和阿尔茨海默病(AD)作为老年人常见病，发病率随年龄增长而增高。为了探究两种疾病之间是否存在共同致病因素，从而为AD的早期诊断提供理论依据，本研究利用单细胞转录组数据和Bulk RNA-seq测序数据解析牙周炎与AD之间致病风险的相关性。方法 从基因表达数据集(GEO)数据库下载牙周炎(GSE164241)和AD(GSE157827)单细胞数据，包括3例患者样本与3例对照。对单细胞数据进行质控、数据整合、降维聚类、细胞类型注释及差异表达基因鉴定。比较两种疾病组间差异表达基因，获取共有的差异表达基因。随后对共有差异表达基因进行富集分析，并针对基因所编码蛋白构建蛋白质-蛋白质相互作用(PPI)网络以了解蛋白之间的相互作用关系。从GEO数据库下载牙周炎(GSE16134)与AD(GSE63060)的Bulk RNA-seq芯片测序表达矩阵与样本信息，验证单细胞数据中PPI的核心基因表达量，评估基因与疾病的相关性。结果 通过对比牙周炎和AD的样本数据分析，发现牙周炎与AD中共有的免疫细胞为CD163~+髓系细胞群，其中牙周炎来源的髓系细胞，疾病组/对照组发现1 934个下调的差异表达基因，AD来源的髓系细胞，疾病组/对照组发现232个下调的差异表达基因，两者取交集后得到49个共有的下调差异表达基因，对其进行富集分析，主要富集于髓系细胞和补体相关反应等。进一步分析表明补体通路中的STAB1基因表达与牙周炎和AD呈显著负相关(P<0.05)。结论 髓系细胞是牙周炎和AD共有的免疫细胞，其中补体通路中STAB1基因是两种疾病发生过程中共同下调的免疫相关基因，并且与疾病的发生呈显著负相关，提示牙周炎患者中STAB1基因表达的检测可作为AD早期诊断和治疗的潜在靶点。更多还原

【Abstract】 Objective Periodontitis and Alzheimer’s disease are prevalent among the elderly, with an incidence that increases with age. To investigate the potential common pathogenic factors between the two diseases and provide a theoretical basis for the early diagnosis of Alzheimer’s disease, the study analyzed the pathogenic risk correlation between periodontitis and Alzheimer’s disease using single-cell transcriptomics data and Bulk RNA-seq sequencing data. Methods Single-cell data for PD(GSE164241) and AD(GSE157827) were downloaded from the Gene Expression Omnibus(GEO) database, including samples from 3 patients and 3 controls for each condition. The single-cell data were subjected to quality control, data integration, dimensionality reduction clustering, cell type annotation, and differential gene expression identification. Shared differentially expressed genes between the two diseases were identified by comparing the gene expression profiles. Enrichment analysis of these shared genes was conducted, followed by the construction of a protein-protein interaction(PPI) network to understand the interactions between proteins. Bulk RNA-seq microarray expression matrices and sample information for PD(GSE16134) and AD(GSE63060) were downloaded from the GEO database to validate the expression levels of core genes in the PPI network from the single-cell data and to assess the correlation between genes and diseases. Results Comparative analysis of sample data from periodontitis and Alzheimer’s disease revealed CD163~+ myeloid cells as a common immune cell type in both conditions. In periodontitis-derived myeloid cells, 1934 downregulated differentially expressed genes were found in the disease group compared to the control group, while in Alzheimer’s disease-derived myeloid cells, 232 downregulated genes were identified, with an intersection of 49 shared downregulated genes. Enrichment analysis of these genes primarily highlighted myeloid cell and complement system-related responses. Further analysis showed that the expression of STAB1 gene in the complement system was significantly negatively correlated with both periodontitis and Alzheimer’s disease. Conclusion Myeloid cells are a common immune cell type in both periodontitis and Alzheimer’s disease. STAB1 acts as a downstream target of complement pathway closely related to both diseases and shows a significant negative correlation with disease onset. This suggests that the detection of STAB1 gene expression levels in periodontitis patients could serve as potential targets for the early diagnosis and treatment of Alzheimer’s disease.更多还原