Synovial fluid transcriptome dynamics in osteoarthritis progression: Implications in pathogenesis

Abstract

Background: Osteoarthritis, a degenerative joint disease associated with various pathological manifestations in the joint including cartilage loss, alterations in subchondral bone and synovial inflammation. Objective: This study aimed to elucidate the transcriptional and molecular changes in synovial fluid associated with OA progression, focusing on differential gene expression and pathway enrichment across OA grades. Methodology: Patients with different OA grades were recruited from PGIMER, Chandigarh, following the KL classification. Microarray analysis was conducted to study the transcriptional profiles in different OA grades using a fold-change (FC) cutoff of 2 and a p-value cutoff of 0.05, followed by pathway analysis performed using GSEA and STRING database. Selected genes from microarray and pathway analysis were validated using qRT-PCR. Results: Microarray analysis reveals distinct gene expression patterns corresponding to different OA stages (KL grade 2 to KL grade 4). Notably, the upregulation of AMTN and DKK2, alongside the downregulation of MSLN, highlighted their roles in pathological mineralization and disrupted bone remodeling in OA. Pathway enrichment analysis revealed significant changes in immune response, inflammation related pathways and cellular processes such as autophagy and programmed cell death, indicating their involvement in disease progression. Furthermore, mitochondrial dysfunction and impaired autophagy were linked to increased inflammation in advanced OA. Conclusion: These findings suggest that targeting mineralization and inflammatory pathways could offer novel therapeutic avenues for OA management.