血管内皮细胞微粒在脓毒症大鼠血管渗漏中的作用

Role of vascular endothelial cell-derived microparticles in vascular leakage in rats after sepsis

目的探讨血管内皮细胞微粒在脓毒症大鼠血管渗漏中的作用。方法采用盲肠结扎穿孔术(cecal ligation and puncture,CLP)复制大鼠脓毒症模型,用流式细胞术及透射电镜对微粒进行鉴定,观察脓毒症大鼠血管渗漏变化与血液中微粒之间的关系;检测脓毒症大鼠来源微粒和LPS刺激肺静脉内皮细胞、血小板和中性粒细胞产生的微粒对正常大鼠和单层肺静脉内皮细胞通透性的影响及与紧密连接的关系。结果脓毒症大鼠肺、肾、肠血管通透性及血液中微粒含量均随时间显著增加(P<0.05);脓毒症大鼠来源微粒可显著增加正常大鼠肺、肾、肠血管通透性(P<0.01)。LPS刺激血管内皮细胞产生的微粒可以显著增加正常大鼠肺血管通透性(P<0.05),而LPS刺激血小板和中性粒细胞产生的微粒对正常大鼠肺血管通透性无明显作用。LPS刺激血管内皮细胞产生的微粒也可明显降低单层肺静脉内皮细胞跨膜电阻(P<0.01),降低肺静脉内皮细胞紧密连接ZO-1表达(P<0.05)。结论内皮细胞微粒可以参与脓毒症大鼠血管渗漏的调节,其机制可能与影响血管内皮细胞间紧密连接有关。

Objective To investigate the role of microparticles derived from vascular endothelial cells in vascular leakage in rats after sepsis. Methods Sepsis rat model was prepared by cecal ligation and puncture（ CLP） operation. The microparticles obtained from sepsis rats were identified by flow cytometry and transmission electron microscopy. The change of vascular leakage and the concentration of microparticles were detected. Meanwhile,the effects of microparticles obtained from sepsis rats and different cells（ vascular endothelial cells,platelets and neutrophil granulocytes） on vascular leakage and endothelial cell permeability,and the relationship with tight junction were analyzed. Results The vascular permeability of lung,kidney and intestine and the concentration of blood microparticles were all increased significantly after sepsis in rats（ P〈0. 05）. Microparticles obtained from sepsis rats enhanced the vascular permeability of lung,kidney and intestine（ P〈0. 01）. Microparticles derived from LPS-stimulated vascular endothelial cells increased the pulmonary vascular permeability significantly（ P〈0. 05）,while microparticles derived from LPS-stimulated platelets and neutrophil granulocytes showed no such effect. Meanwhile,vascular endothelial cell-derived microparticles reduced the transmembrane electric resistance of monolayer pulmonary vein endothelial cells（ P〈0. 01） and the expression of tight junction protein ZO-1（ P〈0. 05）. Conclusion Endothelial cellderived microparticles play an important role in the vascular leakage after sepsis,which is closely related to the tight junction among vascular endothelial cells.