Normal levels of anticoagulant heparan sulfate are not essential for normal hemostasis
Normal levels of anticoagulant heparan sulfate are not essential for normal hemostasis
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DOI：
10.1172/jci200315809
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发表时间：
2003-04-01
影响因子：
15.9
通讯作者：
Shworak, NW
中科院分区：
文献类型：
--
作者：
HajMohammadi, S;Enjyoji, K;Shworak, NW
内皮细胞产生抗凝剂硫酸乙酰肝素(HSact)受HS3ST1基因控制，该基因编码限速酶3-O-硫酸乙酰肝素转移酶-1(3-OST-1)。在体外，HSact显著增强抗凝血酶对凝血酶的中和作用。通过建立HS3ST1(-/-)基因敲除小鼠，评价HSact在体内的作用。HS3ST1(-/-)动物血浆和组织提取液中3-OST-1酶活性缺失。Null显示HSact的组织水平显著降低，但在常氧和低氧条件下保持组织纤维蛋白积累的野生水平。鉴于血管HSact主要发生在内皮下基质中，小鼠接受了颈动脉损伤试验，在该试验中，三氯化铁导致去内皮化和闭塞性血栓形成。HS3ST1(-/-)和HS3ST1(+/+)小鼠的闭塞时间没有区别，凝血酶-抗凝血酶复合体水平相当。因此，HS3ST1(-/-)小鼠没有表现出明显的促凝血表型。相反，HS3ST1(-/-)小鼠表现出遗传背景特有的致死性和宫内生长迟缓，没有明显凝血障碍的证据。我们的结果表明，3-OST-1酶产生了组织HSact的大部分。令人惊讶的是，这种剂量的HSact对小鼠的正常止血并不是必需的。相反，3-OST-1缺陷小鼠表现出意想不到的表型，这表明HSact或额外的3-OST-1衍生结构可能起到替代的生物学作用。
Endothelial cell production of anticoagulant heparan sulfate (HSact) is controlled by the Hs3st1 gene, which encodes the rate-limiting enzyme heparan sulfate 3-O-sulfotransferase-1 (3-OST-1). In vitro, HSact dramatically enhances the neutralization of coagulation proteases by antithrombin. The in vivo role of HSact was evaluated by generating Hs3st1(-/-) knockout mice. Hs3st1(-/-) animals were devoid of 3-OST-1 enzyme activity in plasma and tissue extracts. Nulls showed dramatic reductions in tissue levels of HSact but maintained wild-type levels of tissue fibrin accumulation under both normoxic and hypoxic conditions. Given that vascular HSact predominantly occurs in the subendothelial matrix, mice were subjected to a carotid artery injury assay in which ferric chloride administration induces de-endothelialization and occlusive thrombosis. Hs3st1(-/-) and Hs3st1(+/+) mice yielded indistinguishable occlusion times and comparable levels of thrombin.antithrombin complexes. Thus, Hs3st1(-/-) mice did not show an obvious procoagulant phenotype. Instead, Hs3st1(-/-) mice exhibited genetic background-specific lethality and intrauterine growth retardation, without evidence of a gross coagulopathy. Our results demonstrate that the 3-OST-1 enzyme produces the majority of tissue HSact. Surprisingly, this bulk of HSact is not essential for normal hemostasis in mice. Instead, 3-OST-1-deficient mice exhibited unanticipated phenotypes suggesting that HSact or additional 3-OST-1-derived structures may serve alternate biologic roles.