Supplementary file 1_Differential proteomic analysis of lung tissues in rats with high-altitude pulmonary edema and screening of potential biomarkers.docx

Candidate proteins were further validated using Western blotting, immunohistochemistry, and RT-qPCR.</p>Results<p>HAPE rats exhibited prominent pulmonary edema characterized by increased lung W/D ratios, elevated BALF protein leakage, enhanced production of inflammatory cytokines, and marked interstitial edema. Proteomic analysis identified 5,250 proteins, among which 288 DEPs were detected, including 160 upregulated and 128 downregulated proteins.

Functional enrichment analysis revealed that these DEPs were primarily associated with immune and inflammatory responses, extracellular matrix organization, glycerophospholipid metabolism, phosphatidylinositol signaling, and cell adhesion pathways. Multi-level validation confirmed increased expression of MMP9, MMP8, Serpine1 (PAI-1), MPO, HK3, and MAP3K6 at both protein and transcriptional levels. PPI network analysis indicated that MMP9 represented a central hub protein with the highest interaction connectivity.</p>Conclusion<p>This study provides a comprehensive proteomic profile of HAPE lung tissue and highlights the involvement of neutrophil-associated inflammation, extracellular matrix remodeling, fibrinolytic regulation, and metabolic adaptation in HAPE progression.

The identified proteins, particularly MMP9, may serve as potential biomarkers and candidates for further mechanistic investigation.</p>