Expression of human tissue factor under the control of the mouse tissue factor promoter mediates normal hemostasis in knock-in mice
Expression of human tissue factor under the control of the mouse tissue factor promoter mediates normal hemostasis in knock-in mice
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DOI：
10.1111/j.1538-7836.2008.02833.x
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发表时间：
2008-02-01
影响因子：
10.4
通讯作者：
Yang, J.
中科院分区：
文献类型：
--
作者：
Snyder, L. A.;Rudnick, K. A.;Yang, J.
背景资料：组织因子（TF）广泛表达于血管腔下表面，是外源性凝血途径的主要细胞启动因子。缺乏TF的小鼠在子宫内导致死亡，但人TF（huTF）在低水平表达的人小基因拯救无效小鼠从产前死亡。虽然这些低TF表达转基因小鼠发育到足月，但它们的寿命明显缩短，并表现出心脏出血和纤维化。研究方法：通过用huTF完整编码序列替换小鼠（鼠）TF（muTF）基因的前两个外显子，从而将其置于内源muTF启动子的控制下，产生人TF敲入（TFKI）小鼠。结果：TFKI小鼠中huTF的表达与野生型（wt）小鼠中muTF的表达相似。TFKI小鼠在18个月龄时未显示心脏自发性出血的显微镜证据，也未显示心脏纤维化。免疫组织化学显示huTF在TFKI小鼠血管周围细胞中表达。来自TFKI小鼠的脑匀浆的凝血活性与来自野生型脑的凝血活性相当。当用中和性抗huTF单克隆抗体阻断huTF时，TFKI小鼠发生了与低TF转基因小鼠相似的心脏出血。结论：我们建立了一个转基因小鼠系，在内源性muTF启动子的控制下，在生理水平上表达huTF。我们的研究结果表明，huTF可以完全重建小鼠凝血系统，并介导正常的止血。
Background: Tissue factor (TF) is expressed widely at the subluminal surface of blood vessels and serves as the primary cellular initiator of the extrinsic pathway of blood coagulation. Lack of TF in mice resulted in lethality in utero, but human TF (huTF) expressed at low levels from a human minigene rescued null mice from prenatal death. Although these low-TF expressing transgenic mice developed to term, they had a significantly shorter life span and exhibited hemorrhage and fibrosis in the heart. Methods: Human TF knock-in (TFKI) mice were generated by replacing the first two exons of the mouse (murine) TF (muTF) gene with the huTF complete coding sequence, thus placing it under the control of the endogenous muTF promoter. Results: Expression of huTF in the TFKI mice was similar to muTF in wild-type (wt) mice. The TFKI mice showed no microscopic evidence of spontaneous hemorrhage in the heart, nor cardiac fibrosis at up to 18 months of age. Immunohistochemistry showed that huTF was expressed in cells surrounding blood vessels in TFKI mice. Coagulation activity of brain homogenates from TFKI mice was comparable with that from wt brain. Cardiac hemorrhage similar to that of the low-TF transgenic mice occurred in the TFKI mice when huTF was blocked by a neutralizing anti-huTF monoclonal antibody. Conclusion: We generated a transgenic mouse line that expresses huTF under the control of the endogenous muTF promoter at physiological levels. Our results suggest that huTF can fully reconstitute the murine coagulation system and mediate normal hemostasis.