P-selectin anchors newly released ultralarge von Willebrand factor multimers to the endothelial cell surface
P-selectin anchors newly released ultralarge von Willebrand factor multimers to the endothelial cell surface
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DOI：
10.1182/blood-2003-08-2956
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发表时间：
2004-03-15
期刊：
影响因子：
20.3
通讯作者：
Dong, JF
中科院分区：
文献类型：
--
作者：
Padilla, A;Moake, JL;Dong, JF
从内皮释放的血管性血友病因子 (VWF) 超大 (UL) 且反应过度。如果直接释放到血浆中，它可以自发聚集血小板，导致全身血栓形成。 ADAMTS13（具有 ThromboSpondin 基序的 ADisintegrin 和金属蛋白酶）将 ULVWF 切割成更小、活性较低的形式，从而避免了这种灾难性后果。我们之前表明，ULVWF 在释放时会形成极长的弦状结构。 ADAMTS13 在流动条件下切割这些字符串的速度明显快于静态条件下的速度。由于 ULVWF 束缚在内皮对其快速蛋白水解非常重要，因此我们研究了 2 种分子锚定 ULVWF 串的潜力：P-选择素和整合素 CNN。我们证明了 P-选择素通过多种方式将 ULVWF 锚定于内皮细胞。首先，表达 P-选择素的中国仓鼠卵巢 (CHO) 细胞特异性粘附到固定化的 ULVWF 和 ULVWF 包被的珠子上。其次，抗 VWF 抗体从组胺激活的内皮细胞中共免疫沉淀 P-选择素。第三，P-选择素抗体或可溶性P-选择素，但不是α(v)β(3)抗体、RGDS肽或肝素，阻断ULVWF串的形成。第四，P-选择素表达主要沿着 ULVWF 线呈簇状。最后，测得最小 ULVWF-P-选择素键的强度为 7.2 pN。因此，我们得出结论，P-选择素可能将 ULVWF 串锚定于内皮细胞，并促进 ADAMTS13 对其进行切割。 (C) 2004 年，美国血液学会。
von Willebrand factor (VWF) released from endothelium is ultralarge (UL) and hyperreactive. If released directly into plasma, it can spontaneously aggregate platelets, resulting in systemic thrombosis. This disastrous consequence is prevented by the ADAMTS13 (ADisintegrin and Metalloprotease with ThromboSpondin motif) cleavage of ULVWF into smaller, less active forms. We previously showed that ULVWF, on release, forms extremely long stringlike structures. ADAMTS13 cleaves these strings under flow significantly faster than it does under static conditions. As ULVWF tethering to endothelium is important for its rapid proteolysis, we investigated 2 molecules for their potential to anchor the ULVWF strings: P-selectin and integrin CNN. We demonstrated that P-selectin anchors ULVWF to endothelium by several means. First, Chinese hamster ovary (CHO) cells expressing P-selectin specifically adhered to immobilized ULVWF and ULVWF-coated beads to immobilized P-selectin. Second, an anti-VWF antibody coimmunoprecipltates P-selectin from the histamine-activated endothelial cells. Third, P-selectin antibody or soluble P-selectin, but not a alpha(v)beta(3) antibody, RGDS peptide, or heparin, blocked the formation of ULVWF strings. Fourth, P-selectin expression was in clusters predominantly along the ULVWF strings. Finally, the strength of the minimal ULVWF-P-selectin bond was measured to be 7.2 pN. We, therefore, conclude that P-selectin may anchor ULVWF strings to endothelial cells and facilitate their cleavage by ADAMTS13. (C) 2004 by The American Society of Hematology.