Endothelial oxidative stress activates the lectin complement pathway - Role of cytokeratin 1
Endothelial oxidative stress activates the lectin complement pathway - Role of cytokeratin 1
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DOI：
10.1016/s0002-9440(10)61779-8
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发表时间：
2001-09-01
影响因子：
6
通讯作者：
Stahl, GL
中科院分区：
文献类型：
--
作者：
Collard, CD;Montalto, MC;Stahl, GL
氧化应激增加内皮细胞甘露糖结合凝集素(MBL)结合，激活凝集素补体途径(LCP)。然而，氧化应激后MBL与内皮细胞结合的分子机制尚不清楚。先前已报道中间丝以抗体非依赖的方式激活经典的补体途径。我们调查了氧化应激是否会增加人脐静脉内皮细胞。人脐静脉内皮细胞(HUVEC)细胞角蛋白1(CK1)表达，并通过MBL结合CK1激活LCP。缺氧(3小时，21%O-2)培养的HUVEC(24小时，1%O-2)可显著增加CK1mRNA(原位杂交)和膜蛋白表达[酶联免疫吸附试验(EL ISA)/共聚焦显微镜]。人血清(HS)与N-乙酰-D-氨基葡萄糖胺或抗人MBL单抗孵育可减少MBL和C3在纯化的CK1上的沉积(EL ISA)。CK1和MBL从HS复氧的缺氧HUVECs中免疫共沉淀。使用抗人细胞角蛋白Fab片段治疗可减少氧化应激后内皮细胞MBL和C3的沉积(ELISA/共聚焦显微镜)。我们得出这样的结论。1)内皮氧化应激增加CK1表达、MBL结合和C3沉积；2)MBL抑制纯化的CK1诱导的补体激活；3)抗人细胞角蛋白Fab片段减弱氧化应激后内皮细胞MBL和C3沉积。这些结果提示，MBL与内皮细胞角蛋白结合可能介导氧化应激后LCP的激活。
Oxidative stress increases endothelial mannose-binding lectin (MBL) binding and activates the lectin complement pathway (LCP). However, the molecular mechanism of MBL binding to the endothelium after oxidative stress is unknown. Intermediate filaments have been previously reported to activate the classical complement pathway in an antibody-independent manner. We investigated whether oxidative stress increases human umbilical vein endothelial. cell (HUVEC) cytokeratin 1 (CK1) expression and activates the LCP via MBL binding to CK1. Reoxygenation (3 hours, 21% O-2) of hypoxic HUVECs (24 hours, 1% O-2) significantly increased CK1 mRNA (in situ hybridization) and membrane protein expression [enzyme-linked immunosorbent assay (ELISA)/confocal microscopy]. incubating human serum (HS) with N-acetyl-D-glucosamine or anti-human MBL monoclonal antibody attenuated MBL and C3 deposition on purified CK1 (ELISA). CK1 and MBL were co-immunoprecipitated from hypoxic HUVECs reoxygenated in HS. Treatment with anti-human cytokeratin Fab fragments attenuated endothelial MBL and C3 deposition after oxidative stress (ELISA/confocal microscopy). We conclude that. 1) endothelial oxidative stress increases CK1 expression, MBL binding, and C3 deposition; 2) inhibition of MBL attenuates purified CK1-induced complement activation; and 3) anti-human cytokeratin Fab fragments attenuate endothelial MBL and C3 deposition after oxidative stress. These results suggest that MBL binding to endothelial cytokeratins may mediate LCP activation after oxidative stress.