Transcriptomic analysis for temporomandibular joint arthritis
Background: Temporomandibular joint osteoarthritis (TMJOA) is a degenerative disease marked by the progressive degeneration of cartilage and underlying bone, resulting in pain and functional impairment. Despite current conservative treatments such as physical therapy and NSAIDs, the etiology and pathophysiology of TMJOA are unclear, making effective management difficult. Finding reliable biomarkers for early identification and new therapeutic targets is crucial to improve treatment outcomes. Overall design: Methods: The goal of this study was to identify possible salivary biomarkers for TMJ-OA through an integrative strategy that included both in silico  and clinical validation. Transcriptomic data from the Gene Expression Omnibus (GEO) dataset GSE205389 were analysed to identify differentially expressed genes (DEGs) in TMJ-OA patients versus healthy controls. RNA sequencing was carried out on saliva samples from both group, TMJ-OA patients and healthy controls. DEGs were validated with quantitative reverse transcription PCR (qRT-PCR). Gene set enrichment analysis (GSEA) and pathway annotation tools such as Metascape were used to uncover biological pathways linked to TMJ-OA. Results: In silico analysis revealed 81 differentially active pathways, with 3554 DEGs substantially associated with TMJOA. Among the top 20 DEGs, CRIP1, PPA1, TARS1 and GCLC were significantly increased in TMJ-OA patients compared to controls. These genes were engaged in inflammation, metabolic processes, and oxidative stress, indicating a role in illness progression. Actin filament polymerization, osteoclast differentiation, and immune regulatory pathways were shown to be significantly enriched. Conclusion: This work reveals CRIP1, PPA1,TARS1 and GCLC as possible salivary biomarkers for TMJ-OA, offering novel insights into disease pathophysiology. The findings imply that these genes could be used as diagnostic markers and therapeutic targets for TMJ-OA, particularly in the Arabic population. Additional large-scale research is required to confirm these biomarkers and investigate targeted therapies for illness management. Temporomandibular joint osteoarthritis (TMJOA) and healthy control