Human endothelial cells synthesize protein Z, but not the protein Z dependent inhibitor
Human endothelial cells synthesize protein Z, but not the protein Z dependent inhibitor
复制标题
DOI：
10.1160/th05-11-0723
复制
发表时间：
2006-02
影响因子：
6.7
通讯作者：
M. Vasse;C. Denoyelle;C. Corbière;P. Litzler;E. Legrand;J. Vannier
中科院分区：
文献类型：
--
作者：
M. Vasse;C. Denoyelle;C. Corbière;P. Litzler;E. Legrand;J. Vannier
蛋白Z（Protein Z，PZ）是从人血浆中分离的一种维生素K依赖性蛋白，是丝氨酸蛋白酶抑制剂（Serpin）的辅因子，称为蛋白Z依赖性蛋白酶抑制剂（Protein Z-dependent protease inhibitor，ZPI）。PZ在动脉粥样硬化的内皮细胞中被免疫学检测到，表明内皮细胞可能参与PZ的产生。在这项研究中，我们分析了PZ和ZPI的合成和释放的人脐静脉内皮细胞（HUVEC），代表大血管，和HMEC-1，微血管内皮细胞系。通过特异性ELISA定量两种细胞类型的上清液和裂解物中的PZ。上清的Western印迹显示存在62 kDa的条带，与由肝癌细胞系HepG 2合成的PZ相同。PZ mRNA在各细胞类型中均有表达。HUVEC中PZ的生物合成不受炎性细胞因子的影响，（与对照相比，蛋白质合成的53.5 ± 14.5%，p < 0.01）和适度增加肿瘤坏死因子（TNF）-α（25 ng/ml）和制瘤素M（5 ng/ml）分别诱导HMEC-1中的肿瘤坏死因子（TNF）-α（126± 8.5%，与对照相比，p< 0.05）。免疫组化结果显示，PZ主要表达于细胞核附近，细胞膜上，在正常血管内皮细胞中也有表达。相比之下，在内皮细胞中既没有检测到ZPI也没有检测到其mRNA。
Summary Protein Z (PZ) is a vitamin K-dependent protein isolated from human plasma, and acts as a cofactor fora serpin, called protein Z-dependent protease inhibitor (ZPI).A prothrombotic phenotype has been reported in PZ deficient mice, and PZ deficiencies have been observed in patients with arterial thrombotic events. PZ was immunologically detected in the endothelium of atherosclerotic arteries, suggesting that endothelial cells could be involved in the production of PZ.In this study we analyzed the synthesis and release of PZ and ZPI by human umbilical vein endothelial cells (HUVEC), representative of the macrovasculature, and by HMEC-1, a microvascular endothelial cell line. PZ was quantified bya specific ELISA in the supernatant and in the lysates of both cellular types. Western blotting of the supernatants showed the presence of a band of 62 kDa,identical to PZ synthesized by the hepatoma cell line HepG2. mRNA of PZ was also detected in each cellular type. PZ biosynthesis was unaffected by inflammatory cytokines in HUVEC, whereas a slight decrease of mRNA and PZ antigen (53.5 ± 14.5% of protein synthesis as compared to the control, p < 0.01) and a modest increase (126± 8.5% as compared to the control, p< 0.05) were induced respectively byTumor Necrosis Factor (TNF)-alpha (25 ng/ml) and oncostatin M (5 ng/ml) in HMEC-1. Immunological studies showed the presence of PZ near the nucleus and a possible expression of PZ at the membrane.In addition, PZ was present in the endothelial cells of both normal arterial and venous vessel sections. In contrast, neither ZPI nor its mRNA was detected in endothelial cells.