Exploring the inflammatory origins of gouty arthritis: mechanistic studies based on local lesion proteomics and validation.

Background: The exact pathogenesis of gouty arthritis (GA) is unclear. However, it is believed that GA is characterized by recurrent episodes and a self-limiting nature. During episodes, the disease primarily manifests locally, making local omics research particularly relevant. Objective: Based on the local proteomic analysis of GA patients during the chronic phase (with tophi) and acute phase (with joint cavity effusion), this study systematically screened for inflammation-related differentially expressed proteins to provide specific biomarkers and potential intervention targets for disease prevention and treatment. Methods: Through a cross-sectional study, the baseline data were collected from the GA patients with chronic phase (with tophi) and acute phase (with joint cavity effusion)(n = 100 per group). Five cases were randomly selected from each group for local proteomics analysis to determine the biological functions and enriched signaling pathways of differentially expressed proteins. Based on the differential results, 30 additional cases were randomly selected from each group for validation using Western blot analysis. Results: The quantitative proteomics analysis identified a total of 810 differentially expressed proteins between the two groups, including 548 upregulated and 262 downregulated proteins. The GO and KEGG pathway enrichment analysis showed that the differential proteins were associated with ferroptosis. Ultimately, three ferroptosis-related differential proteins, including glutathione peroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), arachidonate and 15-lipoxygenase (ALOX15) were identified in GA patients. The differential expression of these proteins was validated using Western blot, showing statistically significant differences ( Conclusions: The comprehensive analysis of proteomics and Western blot validation experiments showed that local lesions in the chronic phase of GA exhibited increased expression levels of GPX4 and FTH1, while local lesions in the acute phase of GA exhibited increased expression of ALOX15. Therefore, it was speculated that ferroptosis-inhibiting factors in the chronic phase of GA might participate in the chronic progression of the disease by limiting the toxicity of free iron. In the acute phase of GA, ferroptosis-promoting factors were activated in the joint microenvironment. This study revealed the differential expression of ferroptosis-related proteins at different stages of GA, providing a theoretical basis for developing GA staging and treatment strategies based on ferroptosis regulation.