EXPRESS: Identification of Acetylation-Related Molecular Signatures in Knee Osteoarthritis Patients with Significant Response to Warm-Needle Acupuncture Using Machine-Learning Approaches

Objective: This study aims to delineate remodeling effects of acetylation-related gene expression in knee osteoarthritis (KOA) patients markedly responsive to warm-needle acupuncture (WNA) and identify key genes and immunoregulatory mechanisms. Methods: A prospective self-paired design recruited 34 KOA patients to donate whole-blood samples before and after WNA treatment and further enroll them to perform transcriptome sequencing. Differential expression analysis identified acetylation-related genes followed by enrichment and protein–protein interaction analyses. Key genes were extracted via feature selection based on LASSO and SVM-RFE methods and further used to establish and validate a multigene logistic regression model. Consensus clustering was implemented to divide two acetylation subtypes (ACEcluster A/B) and further explore their immune characteristics by ssGSEA and immune-cell infiltration profiling. Results: After treatment, samples exhibited global up-regulation of acetylation-related genes enriched in protein acetylation and acetyltransferase complex pathways. Further, four genes (SPRED1, HDAC3, NSRP1 and DUSP1) exhibited stable performance and were further used to build a nomogram and achieve high discriminative performance (AUC = 0.908 training; 0.880 validation). Subtype B displayed higher acetylation activity and immune-cell infiltration. Co-expression analysis on 452 acetylation-related genes extracted 107 highly co-regulated candidates and further clustered into two groups coinciding with ACEcluster classification. Conclusion: WNA markedly remodels peripheral-blood acetylation-related transcriptomic network in KOA and associates stronger acetylation activity with immune-cell activation. The four-gene nomogram provides both mechanistic information and possibility for individualized prediction of WNA efficacy.