Protein Z‐dependent protease inhibitor W303X mutation in venous thrombosis
Protein Z‐dependent protease inhibitor W303X mutation in venous thrombosis
复制标题
静脉血栓形成中蛋白 Z 依赖性蛋白酶抑制剂 W303X 突变
DOI：
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发表时间：
2005
影响因子：
6.5
通讯作者：
J. Corral
中科院分区：
文献类型：
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作者：
R. González;E. Pérez;V. Vicente;J. Corral
我们怀着极大的兴趣阅读了货车de Water等人（2004年）的报告。尽管在过去的四十年中付出了相当大的努力，但很少有遗传异常被确定为增加静脉血栓形成的风险。影响抗凝蛋白（抗凝血酶和蛋白C）的罕见突变具有显著的促血栓形成作用，最近报告了两种常见的多态性可略微增加静脉血栓形成的风险（Ridker，2002）。凝血酶原G20210 A多态性首先由Poort et al（1996）描述，是最新明确证实的静脉血栓形成遗传风险因素（Ridker，2002）。从那时起，已经评估了影响大多数经典止血蛋白的数百种多态性，结果非常令人沮丧（Lane & Mollica，2002）。似乎有必要研究其他可能与止血系统不明确相关的蛋白质。在这种情况下，货车de Water等人（2004年）提出了两个有趣的结论。首先，一种在止血系统中具有未知生理作用的蛋白质，丝氨酸蛋白酶抑制剂蛋白Z依赖性蛋白酶抑制剂（ZPI），可能在静脉血栓形成中起重要作用。当然，这种分子可能包含在抗凝蛋白中，因为已经表明它抑制活化的凝血因子X和XI（Han等人，2000）。因此，该丝氨酸蛋白酶抑制剂的功能性和/或抗原性缺陷可能增加静脉血栓形成的风险，与抗凝血酶、其他关键止血丝氨酸蛋白酶抑制剂的缺陷类似（Quinsey et al，2004）。不幸的是，目前没有方法可以确定ZPI的水平或活性，以测试其在这种病理学中的可能相关性。然而，其次，在来自奥克兰（新西兰）的250名静脉血栓形成患者和250名对照中筛选ZPI基因的整个编码序列，发现8名患者（3.2%）存在一个终止突变（W303 X），但对照中没有（货车de Water et al，2004）。不幸的是，作者没有进行家族性研究来证实这一有趣的观察结果，但很明显，根据这些结果，我们正在处理与静脉血栓形成有关的相关遗传风险因素。因此，测试这种突变是否也存在于其他人群中至关重要。我们在218名患有静脉血栓的西班牙白色患者中筛选了这种突变。从我们医院（穆尔西亚综合大学医院）连续招募了109例患者。根据血栓形成倾向（不常见部位的静脉血栓形成，年轻或复发性发作，或静脉血栓形成家族史）的存在从同一地区选择了109例患者。排除继发于恶性肿瘤的血栓形成患者。使用货车de Water et al（2004）描述的外显子3引物，通过聚合酶链反应（PCR）扩增和两种筛选方法分析ZPI W303 X突变：PCR单链构象多态性（PCR-SSCP）分析和PCR等位基因特异性限制性分析（PCR-ASRA）使用HinfI（该酶区分正常等位基因（371 bp）与突变等位基因（292 + 79 bp-）。通过测序证实了扩增。然而，在我们的研究中评估的任何患者中均未发现终止突变W303 X。我们的研究结果支持ZPI W303 X突变可能是创始突变，仅限于特定人群，在静脉血栓形成中肯定可能发挥重要作用。需要进一步研究以在其他人群中检测该突变，特别是在具有与货车de Water等人（2004）评价的样本相似的遗传背景的人群中，并确认其在新西兰的血栓形成作用。这些研究将支持ZPI在止血和血栓形成中的相关性，鼓励在其他人群中寻找编码这种蛋白质的基因中的其他异常。
We read with great interest the report by Van de Water et al (2004). Despite considerable effort over the last four decades, few genetic anomalies have been identified to increase the risk of venous thrombosis. Rare mutations affecting anticoagulant proteins (antithrombin and protein C) have a significant prothrombotic role and, more recently, two common polymorphisms have been reported to slightly increase the risk of developing venous thrombosis (Ridker, 2002). The prothrombin G20210A polymorphism, first described by Poort et al (1996), was the latest, clearly demonstrated genetic risk factor for venous thrombosis (Ridker, 2002). Since then, hundreds of polymorphisms affecting most of the classical haemostatic proteins have been evaluated with quite frustrating results (Lane & Mollica, 2002). It would seem necessary to investigate other proteins that might be not clearly associated with the haemostatic system. In this scenario, Van de Water et al (2004) offer two interesting conclusions. First, a protein with an unknown physiological role in the haemostatic system, the serpin protein Z-dependent protease inhibitor (ZPI), might play a significant role in venous thrombosis. Certainly, this molecule might be included in the anticoagulant proteins, as it has been suggested that it inhibits the activated coagulation factors X and XI (Han et al, 2000). Therefore, functional and/or antigenic deficiency of this serpin might increase the risk of venous thrombosis, similarly to the deficiency of antithrombin, other key haemostatic serpins (Quinsey et al, 2004). Unfortunately, there is currently no method available to determine the levels or activity of ZPI in order to test its possible relevance in this pathology. However, and secondly, the screening of the whole coding sequence of the ZPI gene in 250 patients with venous thrombosis and 250 controls from Auckland (New Zealand) identified one stop mutation (W303X) present in eight patients (3.2%) but not in controls (Van de Water et al, 2004). Unfortunately, the authors did not perform familial studies to confirm this interesting observation, but obviously, according to those results, we are dealing with a relevant genetic risk factor involved in venous thrombosis. Accordingly, it is crucial to test whether this mutation is also present in other populations. We screened this mutation in 218 Spanish White patients with venous thrombosis. One hundred and nine patients were consecutively recruited from our hospital (Hospital General Universitario of Murcia). One hundred and nine patients were selected by the presence of thrombophilia (venous thrombosis in unusual locations, young or recurrent episodes, or family history of venous thrombosis) from the same region. Patients with thrombosis secondary to malignancy were excluded. The ZPI W303X mutation was analysed by polymerase chain reaction (PCR) amplification using the primers for exon 3 described by Van de Water et al (2004) and two screening method: PCRsingle strand conformation polymorphism (PCR-SSCP) analysis and PCRallele-specific restriction assay (PCR-ASRA) using HinfI (this enzyme differentiates the normal allele )371 bpfrom the mutated allele )292 + 79 bp-). The amplification was confirmed by sequencing. However, the stop mutation W303X was not identified in any of the patients evaluated in our study. Our results support that the ZPI W303X mutation could be a founder mutation, restricted to specific populations where it certainly might play a significant role in venous thrombosis. Further studies are required to test this mutation in other populations, especially in those with a genetic background similar to the sample evaluated by Van de Water et al (2004), and to confirm its thrombotic role in New Zealand. These studies would support the relevance of ZPI in haemostasis and thrombosis, encouraging the search of other anomalies in the gene encoding this protein in other populations.