Th17 Cell-Related Gene Biomarkers in Osteoporosis: Comprehensive Bioinformatics Analysis and In Vivo Validation

The interaction between the bone and immune systems has a major role in osteoporosis regulation. However, the infiltration of T helper 17 (Th17) cells and their associated genes in osteoporosis remains unclear. The GSE35959 dataset was obtained from the Gene Expression Omnibus (GEO) database, and the Immune Cell Abundance Identifier (ImmuCellAI) program was used to evaluate the abundance of 24 immune cell types, including Th17 cells. Differential analysis and relevance analysis were performed to identify differentially expressed Th17 cell-related genes (DETh17RGs) in osteoporosis. The potential functions of DETh17RGs were analyzed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment. Hub DETh17RGs were obtained through comprehensive analysis using Weighted Gene Co-Expression Network Analysis (WGCNA) and the CytoHubba plug-in algorithm. The expression levels of hub genes were validated using additional osteoporosis datasets. Additionally, the transcript levels of Hub genes in a mice model of osteoporosis were examined using quantitative PCR (qPCR). 464 DETh17RGs were identified in this study, with 421 genes showing positive associations and 43 genes showing negative associations. Among these, seven genes (CD44, TGFB1, ACTN4, ARHGDIA, ESR1, TLN1, FLNA) were considered as Hub DETh17RGs. The qPCR transcript levels of hub DETh17RGs in a mice model of osteoporosis exhibited consistent expression trends with the bioinformatics analysis. This research enhances our understanding of the molecular mechanisms involving Th17 cells in the development of osteoporosis and contributes to the discovery of potential biomarkers.