Integrated transcriptomic analysis identifies PLAUR as a driver of endothelial-to-mesenchymal transition in atherosclerosis

Atherosclerosis is a chronic inflammatory disease characterized by endothelial dysfunction and plaque instability. Endothelial-to-mesenchymal transition (EndMT) has emerged as a key process contributing to vascular remodeling and disease progression. Soluble urokinase plasminogen activator receptor (suPAR) is a circulating inflammatory marker, yet its functional role and underlying mechanisms in atherosclerosis remain incompletely understood. Public transcriptomic datasets (GSE43292, GSE28829, GSE163154, and GSE118446) were analyzed using differential expression analysis, weighted gene co-expression network analysis (WGCNA), LASSO-logistic regression, and gene set enrichment analysis (GSEA) to identify candidate genes associated with atherosclerosis progression and EndMT. Human umbilical vein endothelial cells (HUVECs) were used for gain- and loss-of-function experiments to evaluate the role of PLAUR. EndMT markers were assessed by qRT-PCR, immunofluorescence, and western blotting. Functional changes were evaluated using tube formation and EdU assays. The involvement of PI3K/AKT/mTOR signaling was examined using pharmacological inhibition and protein phosphorylation analysis. PLAUR was identified as a candidate gene associated with atherosclerotic lesions through integrated transcriptomic analysis. Its expression was significantly increased in advanced plaques and intraplaque hemorrhage samples, and it demonstrated good discriminative performance in independent datasets. GSEA indicated disruption of endothelial junction-related pathways, and PLAUR expression was elevated under EndMT-inducing conditions. In vitro, recombinant suPAR and PLAUR overexpression induced EndMT-like phenotypic changes in endothelial cells, characterized by decreased expression of CD31 and VE-cadherin and increased expression of α-SMA and Vimentin. PLAUR overexpression also impaired angiogenic capacity and reduced proliferative activity. Mechanistically, PLAUR activated PI3K/AKT/mTOR signaling in a phosphorylation-dependent manner, and inhibition of PI3K partially reversed EndMT and endothelial dysfunction. Furthermore, Snail-1 and Twist-1 were identified as downstream transcriptional mediators of PLAUR-induced EndMT. This study demonstrates that PLAUR is a bioinformatically prioritized and functionally validated driver of EndMT in atherosclerosis. The suPAR/PLAUR axis promotes endothelial dysfunction through activation of the PI3K/AKT/mTOR–Snail/Twist signaling cascade. These findings provide mechanistic insight into the role of PLAUR in atherosclerosis and suggest its potential as a therapeutic target for modulating endothelial maladaptation.