Identification of HK3 as a Potential Key Biomarker in the Progression of Temporomandibular Joint Osteoarthritis via RNA Sequencing

The pathogenesis of temporomandibular joint osteoarthritis (TMJOA) is poorly understood. This study aims to identify key biomarkers involved in TMJOA progression and explore potential therapeutic drugs through transcriptome analysis. A rat TMJOA model was established by bilateral injection of monosodium iodoacetate (MIA) into the TMJ cavities. Model validation was conducted using hematoxylin-eosin (HE) and Safranin O-Fast Green (SO-FG) staining. Differentially expressed genes (DEGs) were identified through RNA sequencing. Key pathways were explored using Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and Reactome pathway analyses. DEGs were clustered using MCODE analysis, and Hexokinase 3 (HK3) was identified as a key gene, which was further validated by qPCR. Potential drugs targeting HK3 were selected using the DGIdb database, and molecular docking was conducted to confirm drug-HK3 binding affinity. The TMJOA model was successfully established. RNA-seq analysis revealed 160 upregulated and 97 downregulated DEGs. KEGG, GO, and Reactome pathways analysis identified dysregulated pathways. The top five clusters of DEGs were identified, with HK3 emerging as the key gene. qPCR validation confirmed upregulated HK3 mRNA expression in TMJOA cartilage compared to the control group. Three drugs (MK8719, LY3372689, and Thiamet-G) targeting HK3 were identified through the Drug-Gene Interaction Database (DGIdb) screening, and molecular docking demonstrated high binding affinity between these drugs and HK3. This study suggests that HK3 may play a role in TMJOA progression and could serve as a potential biomarker for inflammatory progression in TMJOA. Targeting HK3 may offer new diagnostic and therapeutic strategies for TMJOA management.