Exploring the mechanisms of age-related osteoarthritis associated with ferroptosis and autophagy using transcriptomics-based integrated analysis

Abstract Ferroptosis and autophagy, parts of regulated cell death, are essential in osteoarthritis, however, their mechanisms in age-related osteoarthritis (OA) are unclear. This study aims to investigate age-related OA cartilage hub genes associated with ferroptosis and autophagy and predict interaction mechanisms. We used GEO2R to identify age-related differentially expressed genes (DEGs) in GSE66554. We intersected DEGs with data from Ferroptosis and Autophagy Database to obtain ferroptosis and autophagy DEGs. We performed differential expression analysis, enrichment analysis, and hub gene screening. After validation of hub genes in GSE33754 with expression patterns analysis, we identified and verified three key hub genes utilising heatmaps, correlation analysis, receiver operator characteristic (ROC) analysis and quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and predicted their interaction mechanisms. We found 27 ferroptosis DEGs and 29 autophagy DEGs associated with cartilage ageing. Enrichment analysis revealed autophagy-related terms. After validation, three key hub genes, lysosomal-associated membrane protein 2 (Lamp2), NRAS proto-oncogene (Nras), and activating transcription factor 6 (Atf6) were identified. ROC analysis demonstrated that their independent and combined use in diagnosing cartilage ageing was accurate. Their expression was found to be consistent with bioinformatic analysis by qRT-PCR. Protein-RNA interaction, transcription factor-DNA interaction, competing endogenous RNA, and protein-protein interaction was predicted, revealing that key hub genes are essential in cartilage ageing. Using bioinformatics and experiments, we identified three key hub genes, Lamp2, Nras, and Atf6, associated with ferroptosis and autophagy in aged cartilage. These findings may help us understand cartilage ageing and treat age-related osteoarthritis.