Dissecting the Genetics of Human Hemostatic Disorders Using Zebrafish

 描述（由申请人提供）：病理性血栓形成是发达国家发病率和死亡率的主要原因。虽然已经确定了诱发性遗传风险因素，但未知的修饰基因导致了在有和没有嗜血栓风险因素的患者和家庭中观察到的不同疾病严重程度和外显率。了解这些修饰因子有助于对血栓形成和复发风险较高的患者进行分类，也可能作为调节出血性疾病严重程度的风险因素提供信息。该项目将利用强大的遗传工具，包括基因组编辑核酸酶，下一代测序和斑马鱼模型，对具有改变人类凝血障碍严重程度潜力的止血调节基因进行大规模评估。在初步研究中，我们已经产生了一个模型的诱导和自发性血栓形成的斑马鱼抗凝血酶III（at 3）基因的靶向突变，使用锌指核酸酶，并表明，这会导致消耗性凝血病和自发性血栓形成。我们已经使用强大的基因组编辑核酸酶（TALENS和CRISPR/Cas）开发了许多额外的凝血因子突变体，并进行了化学诱变筛选，该筛选已鉴定出具有潜在血栓形成修饰基因的潜在抑制突变系。在具体目标1中，我们将使用CRISPR/Cas来评估在at 3缺乏的情况下减少个体凝血因子对自发性血栓形成的影响。在具体目标2中，我们将使用CRISPR/Cas评估这些凝血因子分子的复杂多基因上位相互作用，其水平和通量在哺乳动物系统中是不可能的。具体目标3将使用下一代测序技术分离在我们的诱变实验中产生的抑制突变体的修饰基因。这些研究将确定已知凝血因子之间的关键相互作用以及这些途径的未知修饰剂，这将是增强诊断和治疗人类血栓性和出血性疾病的候选人。

 DESCRIPTION (provided by applicant): Pathologic thrombosis is a leading cause of morbidity and mortality in the developed world. While predisposing genetic risk factors have been identified, unknown modifier genes contribute to the variable disease severity and penetrance observed among patients and families with and without thrombophilic risk factors. Understanding of such modifiers could help classify patients at higher risk for thrombosis and recurrence, and might also be informative as risk factors modulating the severity of bleeding disorders. This project will take advantage of powerful genetic tools, including genome editing nucleases, next generation sequencing, and the zebrafish model to conduct a large scale evaluation of hemostasis regulatory genes with the potential to modify the severity of human coagulation disorders. In preliminary studies, we have produced a model of induced and spontaneous thrombosis by targeted mutagenesis of the zebrafish antithrombin III (at3) gene using zinc finger nucleases, and shown that this results in consumptive coagulopathy and spontaneous thrombosis. We have developed a number of additional coagulation factor mutants using robust genome editing nucleases (TALENS and CRISPR/Cas), and conducted a chemical mutagenesis screen that has identified potential suppressor mutant lines harboring prospective thrombosis modifier genes. In Specific Aim 1, we will use CRISPR/Cas to evaluate the effect of reduction of individual coagulation factors on spontaneous thrombosis in the context of at3 deficiency. In Specific Aim 2, we will evaluate complex multigene epistatic interactions of these coagulation factor molecules using CRISPR/Cas at a level and throughput that is not possible in mammalian systems with current technology. Specific Aim 3 will isolate the modifier genes underlying the suppressor mutants generated in our mutagenesis experiment using next generation sequencing technologies. These studies will identify critical interactions amongst known coagulation factors as well as unknown modifiers of these pathways, which will be candidates for enhanced diagnosis and therapy of human thrombotic and hemorrhagic diseases.