使用基因表达数据分析工具GEO2R从牙周炎数据集GSE10334与GSE16134中筛选差异表达基因并取交集。应用g: Profiler功能富集分析工具，分别对上调及下调基因进行基因本体分析和通路分析。利用在线STRING检索工具构建蛋白相互作用（PPI）网络，并在Cytoscape软件中进行可视化及进一步分析，包括使用cytoHubba、MCODE和iRegulon等插件进行核心基因、关键模块鉴定和转录因子预测。

共筛选出196个牙周炎差异基因，其中上调基因139个，下调基因57个；上调基因参与了免疫系统、病毒蛋白与细胞因子及细胞因子受体的相互作用、细胞因子-细胞因子受体相互作用、白细胞跨内膜迁移和趋化因子受体结合趋化因子等免疫反应相关途径，而下调基因则涉及了角质化包膜形成、角化等途径。PPI网络中处于核心位置的基因为CXC基序趋化因子配体（CXCL）8、CXCL1、CXC 基序趋化因子受体（CXCR）4、选择素（SEL）L、CD19和IKAROS家族锌指（IKZF）1。PPI网络关键模块分别参与趋化因子应答、B细胞受体信号通路和白细胞介素应答。iRegulon预测结果显示，转录因子干扰素调节因子（IRF）4可信度最高。

牙周炎的发病机制与牙龈组织中CXCL8、CXCL1、CXCR4、SELL、CD19和IKZF1等基因的表达变化密切相关，转录因子IRF4可能是重要的上游调控因子。

GEO2R was used to screen DEGs in GSE10334 and GSE16134. Then, the overlapped DEGs were used for further analysis. g:Profiler was used to perform Gene Ontology analysis and pathway analysis for upregulated and downregulated DEGs. The STRING database was used to construct the protein-protein interaction (PPI) network, which was further visua-lized and analyzed by Cytoscape software. Hub genes and key modules were identified by cytoHubba and MCODE plug-ins, respectively. Finally, transcription factors were predicted via iRegulon plug-in.

A total of 196 DEGs were identified, including 139 upregulated and 57 downregulated DEGs. Functional enrichment analysis showed that the upregulated DEGs were mainly enriched in immune-related pathways including immune system, viral protein interaction with cytokine and cytokine receptor, cytokine-cytokine receptor interaction, leukocyte transendothelial migration, and chemokine receptors bind chemokines. On the contrary, the downregulated DEGs were mainly related to the formation of the cornified envelope and keratinization. The identified hub genes in the PPI network were CXCL8, CXCL1, CXCR4, SEL, CD19, and IKZF1. The top three modules were involved in chemokine response, B cell receptor signaling pathway, and interleukin response, respectively. iRegulon analysis revealed that IRF4 scored the highest.

The pathogenesis of periodontitis was closely associated with the expression levels of the identified hub genes including CXCL8, CXCL1, CXCR4, SELL, CD19, and IKZF1. IRF4, the predicted transcription factor, might serve as a dominant upstream regulator.