Identification of BCL3 as a biomarker for chondrocyte programmed cell death in osteoarthritis.

Osteoarthritis (OA) is a condition that is widely prevalent and causes joint pain and disability, with programmed cell death (PCD) playing a role in its pathogenesis. This study aimed to identify biomarkers associated with PCD in OA and explore their potential roles. Three RNA-sequencing datasets (GSE114007, GSE51588 and GSE220243) related to OA were analysed. Differential expression and weighted gene co-expression network identified key differentially expressed PCD-related genes (DE-PRMGs). Potential biomarkers were identified and validated through receiver operating characteristic (ROC) curves, correlation analyses, gene set enrichment analysis, single-cell expression and RT-qPCR. A total of 45 DE-PRMGs were identified, affecting pathways like TNF signalling and RNA degradation. BCL3, TREM2 and NRP2 were prioritized as potential OA biomarkers, which are associated with ribosome function and immune cell infiltration and potentially linked to PCD. The functional role of one of the molecules identified, BCL3, was explored further using a cell model of inflammation induced chondrocytes. BCL3 was significantly down regulated in OA samples from the public dataset and clinical samples analysed by RT-qPCR. BCL3 overexpression reduced apoptosis in chondrocytes stimulated with inflammatory cytokines. Thus the functional studies highlighted the anti-apoptotic role of BCL3 in chondrocytes and provide new insights into OA pathogenesis with potential for future therapeutic development.