Modeling preeclampsia in mice with inducible placenta-specific gene expression

具有可诱导胎盘特异性基因表达的小鼠先兆子痫模型

• 批准号: 8911995
• 负责人: Nihar R Nayak
• 金额: $ 7.9万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8911995
• 关键词: Modeling; preeclampsia; mice; inducible; placenta

Preeclampsia is a serious complication of pregnancy affecting both the mother and fetus, and causing an estimated 14% of pregnancy-related maternal deaths worldwide. Despite its large public health impact, however, its causes are still poorly understood, and there are no known treatments that effectively alleviate the risks for both mother and fetus. Based on clinical studies in the human and experimental studies in rodents, it has been suggested that the abnormal elevation of the circulating levels of soluble fms-like tyrosine kinase 1 (sFlt-1) contributes to the systemic endothelial dysfunction and clinical manifestations of the disease through its antagonism of vascular endothelial growth factor (VEGF) activity. As a result, it is believed that VEGF treatment may reverse the preeclamptic phenotype caused by high sFlt-1 levels in the maternal circulation. However, in preliminary studies, we found, surprisingly, that overexpression of VEGF in pregnant mice results in elevated blood pressure and serum levels of sFlt-1 and soluble endoglin (sEng), and histological changes in the kidneys, similar to the clinical findings of PE in humans and animal models. VEGF has been shown to stimulate sFlt-1 production in several cell types and placental explant cultures in multiple contexts. However, the roles of placental VEGF at different stages of pregnancy, the significance of regulation of its local activity by placental production of sFlt-1, and its potential role in regulating sFlt-1 production in the placenta, has never been examined, primarily due to lack of suitable animal models to test the placenta-specific effects of VEGF. We hypothesize that VEGF activity in the placenta is regulated in a placental developmental stage-specific manner during pregnancy through local production of sFlt-1, and placental VEGF levels may be a primary stimulus for increased production of sFlt-1 in this tissue. Studies in this proposal are designed, first, to develop a novel, inducible, placenta-specific gene expression system, with the ability to monitor gene expression throughout pregancy by live in vivo imaging. This technique will be based on established methods for viral delivery of genes specifically to placental tissue, effective control of consistency in gene expression levels, and a tightly controlled inducible promoter which allows expression to be rapidly switched both on and off. We will then examine the effects of different levels of placental VEGF expression at various time points during pregnancy using this inducible system. To define the physiological role of sFlt-1 during different stages of pregnancy, we will selectively knock down sFlt-1 expression in the placenta using placenta-specific expression of a short hairpin RNA (shRNA) targeted against sFlt-1. The results of these experiments will delineate, for the first time, the local interactions of VEGF and sFlt-1 in regulating VEGF activity in the placenta. Additionally, this entirely novel approach, using a newly-developed, inducible, placenta-specific gene regulation system, will greatly facilitate development of new animal models for the study of both placental disease and normal placental development, and will greatly enable the development of therapies for complications of pregnancy.

子痫前期是影响母亲和胎儿的严重并发症，并导致 估计全世界与怀孕有关的孕妇死亡中估计有14％。尽管公共卫生影响很大，但 但是，其原因仍然很少了解，并且没有已知的治疗方法可以有效地减轻 母亲和胎儿的风险。基于人类和实验研究中啮齿动物的临床研究， 已提出可溶性FMS样酪氨酸激酶1的循环水平的异常升高1 （SFLT-1）通过 其血管内皮生长因子（VEGF）活性的拮抗作用。结果，人们相信VEGF 治疗可能扭转由母体循环中高SFLT-1水平引起的先兆子痫的表型。 但是，在初步研究中，我们发现，孕妇小鼠中VEGF的过表达结果 在升高的SFLT-1和可溶性内源（SENG）的血压和血清水平中，以及组织学变化 肾脏，类似于人类和动物模型中PE的临床发现。 VEGF已被证明 在多种情况下刺激几种细胞类型的SFLT-1产生和胎盘外植体培养物。然而， 胎盘VEGF在妊娠的不同阶段的作用，其局部活动的重要性 通过SFLT-1的胎盘生产及其在调节胎盘中SFLT-1产生中的潜在作用，从来没有 被检查，主要是由于缺乏合适的动物模型来测试VEGF的胎盘特异性作用。 我们假设胎盘中的VEGF活性受到胎盘发育特异性的调节 通过本地生产SFLT-1和胎盘VEGF水平，怀孕期间的方式可能是主要的 该组织中SFLT-1产生的刺激。该提案中的研究首先是为了开发的 一种新型，可诱导的胎盘特异性基因表达系统，具有监测基因表达的能力 在整个生存的体内成像中。该技术将基于既定方法 专门针对胎盘组织的基因，有效控制基因表达水平的一致性，以及 一个紧密控制的诱导启动子，允许表达迅速开关和关闭。我们将 然后检查不同水平的胎盘VEGF表达在不同时间点的影响 使用这种诱导系统的怀孕。在不同阶段的不同阶段定义SFLT-1的生理作用 怀孕，我们将使用胎盘特异性表达选择性地击倒胎盘中的SFLT-1表达 针对SFLT-1的短发夹RNA（shRNA）。这些实验的结果将描绘 第一次，VEGF和SFLT-1在调节胎盘中VEGF活性中的局部相互作用。另外，这个 完全新颖的方法，使用新开发的，诱导的，胎盘特异性的基因调节系统将 极大地促进了新动物模型的发展，以研究胎盘疾病和正常 胎盘发育，将极大地促进妊娠并发症的疗法。