Protective Effect of Low 2-O, 3-O Desulfated Heparin (ODSH) Against LPS-Induced Acute Lung Injury in Mice

Background: Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), are critical conditions lacking effective pharmacologic therapies. Lipopolysaccharide (LPS), a bacterial endotoxin, is a well-established trigger of ALI. Emerging evidence suggests that heparin derivatives may attenuate lung injury, but their mechanisms remain unclear. Methods: This study evaluated the protective effects of 2-O, 3-O desulfated heparin (ODSH) in a murine model of LPS-induced ALI. Mice received LPS intratracheally with or without ODSH pre-treatment. Lung injury was assessed by bronchoalveolar lavage fluid (BALF) analysis, Evans blue dye albumin EBDA) extravasation, and histopathology. Results: ODSH treatment significantly reduced BALF protein concentration, inflammatory cell infiltration, and EBDA leakage. ODSH preserved endothelial barrier function in vitro, as evidenced by transendothelial electrical resistance (TER) measurements in human lung microvascular endothelial cell (HLMVEC) monolayers. Histological assessment (H&E staining) and myeloperoxidase (MPO) staining demonstrated reduced lung injury and neutrophil infiltration in the ODSH group. ODSH also downregulated pro-inflammatory mediators (NF-κB, IL-6, p38 MAPK) and upregulated the anti-inflammatory cytokine IL-10. Conclusions: ODSH mitigates LPS-induced ALI by reducing vascular permeability, neutrophilic inflammation, and pro-inflammatory signaling while enhancing IL-10 expression. These findings suggest ODSH may offer a novel therapeutic approach for treating ALI.