Regulation of endothelial cell function by transgene expression and development of gene therapy for vascular diseases

根据以下观察结果，我们推测纤溶酶原激活剂-纤溶酶依赖的纤溶系统与粒细胞来源的弹性蛋白酶依赖的纤溶系统之间可能存在一种串扰。这些患者的血浆粒细胞来源的弹性蛋白酶水平是正常人的10-100倍。此外，输入纯化的纤溶酶原可将其水平降至正常范围。2、弥散性血管内凝血合并严重脓毒症患者纤溶酶原激活物-纤溶酶依赖性纤溶系统可能因纤溶酶原激活物抑制物-1的显著升高而关闭。使用针对人纤维蛋白粒细胞来源的弹性蛋白酶D片段的单抗的ELISA系统，我们发现这些患者的弹性酶纤维蛋白消化能力大部分升高。为了支持这一假说，我们使用了含有合成弹性酶抑制物的纤溶酶原缺陷小鼠(KO小鼠)。7周龄后，19%的KO小鼠因微循环血管内血栓形成而发生直肠脱垂。出乎意料的是，给予弹性酶抑制剂可以保护KO小鼠免受直肠脱垂的影响。此外，随之而来的弹性酶抑制也减少了脂多糖负荷后肺内白细胞的浸润量和纤维蛋白的沉积。这些结果表明，两个系统之间的串扰更加复杂，需要更多地了解弹性蛋白酶在替代纤溶系统中的作用。

We have hypothesized that there might be a kind of cross-talk between plasminogen activator-plasmin dependent fibrinolytic system and granulocyte-derived elastase dependent one, according to the following observations : 1,congenital plasminogen-deficient patients have no intravascular thrombophilic episodes. The granulocyte-derived elastase level of these patients in plasma is 10-100 times higher than that of the normal. Moreover, infusion of purified plasminogen decreases the level to a normal range. 2, plasminogen activator-plasmin dependent fibrinolytic system is supposed to be shutdown by remarkable increase of plasminogen activator inhibitor -1 in patient with disseminated intravascular coagulation associated with severe sepsis. Using ELISA system employing a monoclonal antibody specific to the granulocyte-derived elastase-fragment D species of human fibrin, we found that the elastase fibrin-digests were mostly elevated in these patients.To support this hypothesis, we used plasminogen-deficient mice (KO mice) with synthetic elastase inhibitor. After the age of 7 weeks, 19% of KO mice develop rectal prolapse due to intravascular thrombosis in microcirculation. Unexpectedly, administration of elastase inhibitor protected KO mice from rectal prolapse. In addition, the amount of leukocyte infiltration and a fibrin deposit in the lung after lipopolysacharride loading were also decreased by concomitant elastase inhibition. These results suggest a cross-talk between two systems is more complicated and much more needs to be learned about the role of elastase in relation to alternative fibrinolytic system.