Cxcl9 as a Marker of Adipose Tissue Changes Caused by Bariatric Surgery and Psoriasis.

BACKGROUND

Bariatric surgery has been shown to improve psoriasis, but the underlying molecular mechanisms remain unclear. This study aimed to investigate shared molecular mechanisms between bariatric surgery-induced adipose changes and psoriasis using bioinformatics approaches.

METHODS

Transcriptomic data from adipose tissue before and after bariatric surgery and from psoriatic lesions were obtained from the GEO database. Common differentially expressed genes (co-DEGs) were identified and subjected to GO/KEGG enrichment analysis, protein-protein interaction network construction, and machine learning-based hub gene selection. Diagnostic performance and immune infiltration characteristics were evaluated.

RESULTS

Co-DEGs were significantly enriched in the IL-17 signaling pathway, defense response to bacterium, response to lipopolysaccharide, cytolysis, and collagen-containing extracellular matrix. CXCL9 was identified as a key hub gene via multiple machine learning algorithms, showing good diagnostic performance in external validation (AUC > 0.85). Immune infiltration analysis revealed that CXCL9 expression was positively correlated with M1 macrophage and CD8⁺ T cell abundance, and negatively correlated with M2 macrophages.

CONCLUSION

CXCL9, through its involvement in the IL-17 signaling pathway and lipopolysaccharide response, may serve as a critical bridge linking adipose tissue inflammation and psoriatic skin immunity, providing a novel molecular target for the improvement of psoriasis following bariatric surgery.