Three-gene signature revealing the dynamics of lymphocyte infiltration in subchondral bone during osteoarthritis progression

• Published in: International immunopharmacology 2024-08, Vol.137, p.112431, Article 112431
• Main Authors: Luo, Sen, Liu, Zeyu, Zhang, Jiewen, Chen, Yuanyuan, Lei, Yutian, Gao, Xu, Liu, ChengYan, Chen, Yutao, Liu, Chenkun, Yan, Peng, Chen, Yang, Li, Heng, Zhao, Chuanchuan, Wang, Haifan, Wang, Kunzheng, Wang, Chunsheng, Tian, Run, Yang, Pei
• Format: Article
• Language: English
• Subjects: Biomarker; Immune infiltration; Lymphocyte; Osteoarthritis; Subchondral bone
• ISSN: 1567-5769; 1878-1705; 1878-1705
• DOI: 10.1016/j.intimp.2024.112431

•Our investigation demonstrates a significant dynamic decline in lymphocyte infiltration within the subchondral bone during OA progression.•Compared to the late stage osteoarthritis, three upregulated genes (POU2AF1, TNFRSF13B, and CD247) identified in early osteoarthritis have been validated as biomarkers related to the growth or activation of T or B cells.•A Three-gene signature predictive staging model can effectively differentiate early- and late-stage OA, offering potential targets for precision intervention and progression stratification. Osteoarthritis (OA), a degenerative joint disorder, has an unclear immune infiltration mechanism in subchondral bone (SCB). Thus, this study aims to discern immune infiltration variations in SCB between early- and late-stages of OA and identify pertinent biomarkers. Utilizing the GSE515188 bulk-seq profile from the Gene Expression Omnibus database, we performed single-sample gene-set enrichment analysis alongside weighted gene co-expression network analysis to identify key cells and immune-related genes (IRGs) involved in SCB at both stages. At the meanwhile, differentially expressed genes (DEGs) were identified in the same dataset and intersected with IRGs to find IR-DEGs. Protein-protein interaction network and enrichment analyses and further gene filtering using LASSO regression led to the discovery of potential biomarkers, which were then validated by ROC curve analysis, single-cell RNA sequencing, qRT-PCR, western blot and immunofluorescence. ScRNA-seq analysis using GSE196678, qRT-PCR, western blot and immunofluorescence results confirmed the upregulation of their expression levels in early-stage OA SCB samples. Our comprehensive analysis revealed lymphocytes infiltration as a major feature in early OA SCB. A total of 13 IR-DEGs were identified, showing significant enrichment in T- or B-cell activation pathways. Three of them (CD247, POU2AF1, and TNFRSF13B) were selected via the LASSO regression analysis, and results from the ROC curve analyses indicated the diagnostic efficacy of these 3 genes as biomarkers. These findings may aid in investigating the mechanisms of SCB immune infiltration in OA, stratifying OA progression, and identifying relevant therapeutic targets.