Constructed protein-protein interaction (PPI) networks and conducted analysis.

(A) Construction of PPI networks based on STRING database data. The circle size represents the MCODE score, where a higher score indicates higher connectivity and dense interactions within the module. These modules typically represent functionally related groups of proteins. A lower score indicates looser connections within the module, potentially signifying weaker functional relationships among these nodes. (B) Selection of high-scoring modules from the STRING network analysis. (C) Identification of key areas involving oxidative stress, immunity, apoptosis, endothelial damage, and ARDS case reports, with 1.5-fold DEPs. A Venn diagram shows the overlapping human proteins across the five categorized groups. (D) A heatmap plotted using the pheatmap R package (version 1.42.2). It displays relative expression levels with intensities of red and blue, indicating the relative increase and decrease of these proteins. (E) Integrated PPI network analysis of the five categorized groups. PPI network analysis was performed using Cytoscape based on the STRING database with high confidence for each category group. Constructed oxidative stress PPI network, consisting of 99 nodes and 199 edges. Constructed apoptosis PPI network, consisting of 192 nodes and 314 edges. Constructed endothelial damage PPI network, consisting of 35 nodes and 71 edges. Constructed inflammatory response PPI network, consisting of 160 nodes and 282 edges. Constructed ARDS case report-related PPI network, consisting of 63 nodes and 129 edges.