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

<h4>Purpose</h4>Ventilator-associated pneumonia (VAP) is a common and serious complication in mechanically ventilated patients, with <i>Pseudomonas aeruginosa</i> (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.<h4>Methods</h4>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.<h4>Results</h4>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.<h4>Conclusion</h4>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.