Functional Difference Between Membrane-bound and Soluble Human Thrombomodulin
Functional Difference Between Membrane-bound and Soluble Human Thrombomodulin
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DOI：
10.1097/tp.0000000000000571
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发表时间：
2015-04
期刊：
影响因子：
6.2
通讯作者：
Y. Miwa;S. Yazaki;M. Iwamoto;Shun'ichi Suzuki;Kenta Iwasaki;M. Haneda;Koji Yamamoto;S. Maruyama;A. Onishi;Takaaki Kobayashi
中科院分区：
文献类型：
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作者：
Y. Miwa;S. Yazaki;M. Iwamoto;Shun'ichi Suzuki;Kenta Iwasaki;M. Haneda;Koji Yamamoto;S. Maruyama;A. Onishi;Takaaki Kobayashi
背景为了成功地进行异种移植，除了敲除1，3-半乳糖基转移酶基因和插入人补体调节蛋白（CD 46，CD 55，CD 59）基因外，还产生了表达人血栓调节蛋白（hTM）的克隆猪，以解决其凝血系统的分子不相容性问题。重组可溶性hTM（S-hTM），最近已被批准用于治疗弥散性血管内凝血可能是潜在的可用。本研究的目的是研究膜结合hTM（MB-hTM）和S-hTM之间的内皮细胞功能差异，并阐明使用两种类型的hTM的有效策略。方法在肿瘤坏死因子激活的条件下，比较表达hTM的克隆猪主动脉内皮细胞（PAEC）与非转基因PAEC在S-hTM存在下的凝血和炎症因子;（i）凝血时间，（ii）猪组织因子（TF），（iii）猪E-选择素，（iv）直接凝血酶原酶活性，（v）活化蛋白C（APC），和（vi）凝血酶原酶活性。结果与S-hTM相比，MB-hTM能显著抑制肿瘤坏死因子激活的PAEC中TF和E-选择素的表达及直接凝血酶原酶的活性，具有较强的抗炎作用。相比之下，S-hTM具有比MB-hTM更有效的抑制凝血酶生成和产生APC的能力，尽管MB-hTM具有与人内皮细胞相同的能力水平。结论据推测，S-hTM治疗将有助于过度凝血酶形成的高风险期（例如，缺血再灌注损伤或严重感染/排斥）。考虑到MB-hTM具有抗炎功能和APC产生的特性，表达hTM的克隆猪可能是移植物内皮细胞长期稳定不可或缺的。
Background For successful xenotransplantation, in addition to 1,3-galactosyltransferase gene-knockout and human complement regulatory protein (CD46, CD55, CD59) gene insertion, cloned pigs expressing human thrombomodulin (hTM) have been produced to solve the problem of molecular incompatibility in their coagulation system. Recombinant soluble hTM (S-hTM) which has been recently approved for treatment of disseminated intravascular coagulation might be potentially available. The purpose of this study is to examine the functional difference in endothelial cells between membrane-bound hTM (MB-hTM) and S-hTM and to elucidate effective strategy using both types of hTM. Methods The following factors regarding coagulation and inflammation were compared between hTM-expressing pig aortic endothelial cells (PAEC) derived from cloned pig and nontransgenic PAEC in the presence of S-hTM under tumor necrosis factor-–activated conditions; (i) clotting time (ii) pig tissue factor (TF), (iii) pig E-selectin, (iv) direct prothrombinase activity, (v) activated protein C (APC), and (vi) prothrombinase activity. Results The MB-hTM significantly suppressed the expression of pig TF and E-selectin and direct prothrombinase activity in tumor necrosis factor-–activated PAEC, suggesting strong anti-inflammatory effect, compared to S-hTM. In contrast, S-hTM had more potent capacity to inhibit thrombin generation and to produce APC than MB-hTM, although MB-hTM had the same level of capacity as human endothelial cells. Conclusions It was speculated that S-hTM treatment would be of assistance during high-risk periods for excessive thrombin formation (e.g., ischemia reperfusion injury or severe infection/rejection). Considering the properties of MB-hTM exhibiting anti-inflammatory function as well as APC production, hTM-expressing cloned pigs might be indispensible to long-term stabilization of graft endothelial cells.