Generation and characterization of knock-in mice carrying the point mutations associated with thrombosis in Japanese

在55名日本人中发现了蛋白S（PS）中的K196 E突变，这是日本人静脉血栓形成的遗传风险因素。在25名日本人中发现了纤溶酶原（PLG）中的A620 T突变，并导致纤溶活性降低。在这项研究中，我们产生了PS-K196 E和PLG-A622 T（对应于人PLG-A620 T）基因敲入小鼠，用于研究这些突变在体内的影响。在诱导肺栓塞后，与野生型小鼠相比，PS-K196 E小鼠显示出肺血管闭塞程度增加和存活率降低。这些结果支持PS-K196 E突变与静脉血栓栓塞易感性增加之间的直接因果关系。为了检测突变对动脉缺血性疾病的影响，在小鼠中施加暂时脑缺血。与野生型小鼠相比，具有凝血因子V-莱顿突变的小鼠表现出更大的梗死和更低的存活率，这是高加索人常见的血栓形成风险。相比之下，PS-K196 E小鼠的脑梗死未加重。与这些发现一致，FV-莱顿突变已被报道为早发性缺血性卒中的危险因素，而没有流行病学数据表明PS-K196 E突变与卒中之间存在显著相关性。PS-196 E小鼠是揭示日本人血栓形成遗传特征的合适动物模型。小鼠PLG-A622 T突变对肺栓塞和脑梗死的严重程度影响不大，表明PLG-A620 T突变本身不会引起血栓形成。

The K196E mutation in protein S (PS) is found in one of 55 Japanese and is a genetic risk factor for vein thrombosis in Japanese. The A620T mutation in plasminogen (PLG) is found in one of 25 Japanese and causes decreased fibrinolytic activity. In this study, we generated PS-K196E and PLG-A622T (corresponding to human PLG-A620T) knock-in mice for investigating effects of these mutations in vivo. Following the induction of pulmonary embolism, PS-K196E mice showed increased degree of lung vascular occlusion and decreased survival compared with wild-type mice. These results support a direct causal relationship between the PS-K196E mutation and increased susceptibility to venous thromboembolism. To examine effects of the mutation on arterial ischemic diseases, temporary cerebral ischemia was applied in mice. Mice with the factor V－Leiden mutation, the common thrombotic risk in Caucasian, showed larger infarction and lower survival than wild-type mice. In contrast, cerebral infarction in PS-K196E mice was not aggravated. Consistent with these findings, the FV-Leiden mutation has been reported as a risk factor for early-onset ischemic stroke, whereas there are no epidemiological data to suggest significant association between the PS-K196E mutation and stroke. The PS-196E mice represent a suitable animal model to uncover genetic characteristics of thrombosis in Japanese. The PLG-A622T mutation in mice had little effect on the severity of pulmonary embolism and cerebral infarction, suggesting that the PLG-A620T mutation does not cause thrombosis by itself.