补体旁路激活导致内皮细胞活化和损伤

目的研究补体替代途径的激活对血管内皮细胞活化和损伤的作用。方法采用眼镜蛇毒因子(CVF)与人血清孵育,特异激活补体替代途径。将孵育物作用于人微血管内皮细胞,采用ELISA检测内皮细胞P-selectin、E-selectin、ICAM-1、MCP-1和IL-8的表达,采用酶活性测定法检测乳酸脱氢酶(LDH)活性,化学发光法检测内皮细胞caspase-8活化信号,MTT法检测内皮细胞增殖活性,并检测内皮细胞释放NO的变化。结果补体旁路激活导致内皮细胞瞬时表达P-selectin,并进而使内皮细胞上调表达E-selectin、ICAM-1、MCP-1和IL-8。内皮细胞经补体激活物刺激后,LDH释放增加、凋亡信号caspase-8活化上调以及NO释放下调,同时,细胞增殖也受到抑制。结论补体旁路激活能诱导内皮细胞活化和损伤,介导血管内皮的生理结构与功能发生变化,从而可能导致相应的炎症和组织损伤。

Endothelial cell activation and injury induced by complement alternative pathway

Aim To investigate the effects of complement activation products of the alternative pathway on endothelial cell activation and injury.Methods Normal human serum was activated by incubated with cobra venom factor(CVF).After exposure of human microvascular endothelial cells to activated complement for various times,supernatants were removed and assayed for expression of P-selectin,E-selectin,ICAM-1,MCP-1,and IL-8 by using ELISA method.LDH leakage,caspase-8 activity,and nitric oxide concentration were determined by assay kits.Cell viability was measured by MTT method.Results P-selectin was rapidly expressed by endothelial cells after exposure to activated complement.Then expression of E-selectin,ICAM-1,MCP-1,and IL-8 was up-regulated.Increased LDH leakage and caspase-8 activity were detected,whereas NO release was decreased.The cell viability was also inhibited.Conclusion Complement alternative pathway can initiate activation and injury of endothelial cells,and may lead to structural and functional alterations of the endothelium resulting in local inflammation and tissue injury.