GEOapplication/xmlftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE313nnn/GSE313973/primaryOK200TranscriptomicsMus musculusExpression profiling by arrayhttps://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE313973GEOGSEfalseEndothelial Ext1 Is Essential for Glycocalyx Integrity and Inflammatory Resolution in Acute Lung InjuryThe endothelial glycocalyx (eGCX) heparan sulfate (HS) is essential for vascular barrier function and inflammation regulation. To elucidate the endothelial cell-autonomous role of the HS synthase Ext1, we generated endothelial-specific Ext1-deficient mice (Ext1flox/flox; VE-cadherin–Cre) and performed endotoxin challenge experiments. Transcriptomic analysis of pulmonary endothelial cells revealed marked down-regulation of HS- and glycocalyx-related genes and up-regulation of immune activation pathways. Fluorescence imaging and dextran extravasation assays confirmed significant depletion of lectin- and HS-labeled glycocalyx and barrier dysfunction. Electron microscopy demonstrated severe baseline loss of luminal glycocalyx. Following LPS administration, Ext1-deficient mice exhibited altered cytokine kinetics, delayed clearance of neutrophils and CD11b⁺ myeloid cells, increased late-phase macrophage accumulation, and prolonged pulmonary edema, indicating impaired resolution of inflammation. Gene set enrichment analysis revealed up-regulation of leukocyte transendothelial migration, chemokine signaling, and VEGF pathways, consistent with sustained endothelial activation.2026/10/07GSE313973GSM9378682GSM9378683GSM9378684GSM9378685GSM9378681GSM9378686GSM9378687GSM937868821163313973Mus musculus[42820257]