Screening and Targeting the HMGB1/RAGE Axis via Proteomics to Alleviate Inflammatory Responses in a Pseudomonas aeruginosa-Induced Rat Model of VAP

Purpose: Ventilator-associated pneumonia (VAP) is a common and serious complication in mechanically ventilated patients, with Pseudomonas aeruginosa (PA) being one of the most frequently encountered pathogens. Dysregulated protein expression is closely associated with the progression of VAP; therefore, identifying and modulating potential protein targets are crucial for developing novel therapeutic strategies. Methods: Quantitative proteomics was employed to analyze protein expression changes in a PA-induced rat model of VAP. Bioinformatics analysis was performed to identify key signaling pathways and potential small-molecule inhibitors. Immuno-infiltration analysis and immunofluorescence co-localization assays were conducted on rat lung tissues. The expression levels of HMGB1, RAGE, TNF-α, IL-1β, and IL-6 in bronchoalveolar lavage fluid (BALF) and blood were measured using ELISA. Results: PA infection induced the upregulation of the HMGB1/RAGE axis. Bioinformatics analysis indicated that the HMGB1/RAGE axis is involved in key pathways such as neutrophil extracellular trap (NET) formation and identified potential small-molecule inhibitors, including potassium nitrate and 2-mercaptoethanol. Immuno-infiltration analysis revealed a negative correlation between the HMGB1/RAGE axis and monocytes. FPS-ZM1-treated rats showed reduced co-expression of HMGB1 and RAGE in lung tissue, decreased levels of HMGB1, RAGE, TNF-α, IL-1β, and IL-6 in BALF and blood, and attenuated systemic inflammatory responses. Conclusion: These results suggest that the HMGB1/RAGE axis is associated with the inflammatory response in a PA-induced rat model of VAP, and that blocking this interaction with FPS-ZM1 alleviates both lung injury and systemic inflammation. Keywords: ventilator-associated pneumonia, high-mobility group box 1, receptor for advanced glycation end products, Pseudomonas aeruginosa , proteomics