【摘要】 目的 探讨肝素酶介导内皮糖萼降解在脓毒症小鼠急性肺损伤发病机制中的作用，并评估肝素酶抑制剂对急性肺损伤的保护效应。方法 采用盲肠结扎穿刺术（cecal ligation and puncture,CLP）建立脓毒症小鼠模型，应用肝素酶特异性抑制剂PG545进行干预。通过HE染色评估肺组织病理变化；采用透射电镜观察肺微血管内皮糖萼结构变化；Western blot检测肝素酶及相关信号通路分子表达；小麦胚凝集素染色检测细胞表面糖萼结构；高效液相色谱-质谱联用检测硫酸乙酰肝素降解产物；ELISA检测炎症因子及内皮功能相关指标水平。结果 CLP小鼠肺组织中肝素酶表达显著上调，内皮糖萼结构严重受损，肺泡-毛细血管膜通透性增加，炎症反应加剧。PG545干预可有效抑制肝素酶活性，减轻内皮糖萼损伤，降低炎症反应，改善肺组织病理损伤。机制研究表明，肝素酶通过激活核因子κB通路促进炎症因子释放，并通过诱导内皮细胞骨架重构破坏内皮屏障功能。结论 肝素酶介导的内皮糖萼降解是脓毒症急性肺损伤的关键病理机制之一；肝素酶抑制剂PG545通过保护内皮糖萼完整性，减轻肺血管通透性的增加和炎症反应，对脓毒症相关急性肺损伤具有显著保护作用，为脓毒症相关急性肺损伤的临床治疗提供新的潜在靶点。更多还原

【Abstract】 Objective To explore the role of heparanase-mediated endothelial glycocalyx degradation in the pathophysiology of acute lung injury(ALI) in septic mice and evaluate the protective effects of heparanase inhibitors on ALI. Methods A septic mouse model was established using cecal ligation and puncture(CLP). The speciflc heparanase inhibitor PG545 was applied for intervention. Lung tissue pathological changes were assessed by HE staining. Transmission electron microscopy was used to observe the structural changes of the pulmonary microvascular endothelial glycocalyx. Western blot was performed to detect the expression of heparanase and related signaling pathway molecules. Wheat germ agglutinin(WGA) staining was utilized to examine the glycocalyx structure on the cell surface. High-performance liquid chromatography-mass spectrometry(HPLC-MS) was employed to detect heparan sulfate degradation products. ELISA was used to measure the levels of inflammatory cytokines and endothelial functionrelated markers. Results In CLP mice, heparanase expression in lung tissue was signiflcantly upregulated, leading to severe damage to the endothelial glycocalyx structure, increased alveolar-capillary membrane permeability, and exacerbated inflammatory responses. PG545 intervention effectively inhibited heparanase activity, reduced endothelial glycocalyx injury, decreased inflammatory reactions, and improved lung tissue pathological damage. Mechanistic studies revealed that heparanase promotes the release of inflammatory cytokines by activating the NF-κB pathway and disrupts endothelial barrier function by inducing endothelial cytoskeletal remodeling. Conclusions Heparanasemediated endothelial glycocalyx degradation is a key pathological mechanism in sepsis-induced acute lung injury. The heparanase inhibitor PG545 exerts signiflcant protective effects on sepsisassociated acute lung injury by preserving the integrity of the endothelial glycocalyx, reducing the increase of lung vascular permeability, and attenuating inflammatory responses, thus providing a new potential target for clinical treatment of sepsis-related acute lung injury.更多还原