VEGF signaling in placental development and disease

每年有30多万妇女死于妊娠并发症， 导致终身残疾的并发症，其中410亿美元用于医疗保健费用。不过小 已知心脏绒毛外滋养层细胞（EVT）的发育和分化 大多数人类妊娠并发症的原因我们的首要目标是制定基于机制的战略， 预防、诊断和治疗与滋养层发育缺陷相关的妊娠并发症。我们 有强有力的证据表明，血管内皮生长因子（VEGF）直接作用于滋养层干细胞 并在滋养层巨细胞的结合带细胞和特定亚型的分化中起关键作用 细胞（TGC），其与人类中的EVT正交。我们发现不同层次的蜕膜 着床部位VEGF过表达刺激胎盘产生有效的内源性VEGF 拮抗剂可溶性fms样酪氨酸激酶1（sFlt1），并诱导小鼠的一系列症状， 从先兆子痫到胎盘早剥。初步数据显示， 这些疾病中的每一种的特定症状都与TGC亚群的异常发育有关 和连接区细胞。因此，我们假设在胎盘早期VEGF的过度表达水平， 发育对应于TGC的特定亚型的异常发育， 妊娠并发症和与过量sFlt1产生相关的疾病可以通过以下方法治疗： sFlt1仅在妊娠后期减少。我们还假设存在不同的EVT亚型， 过量的VEGF可导致人类特定EVT亚型的不成比例的扩增。所以我们 实验将确定VEGF在特定滋养层亚型发育中的作用（目的1）， VEGF的水平在小鼠体内胎盘发育的每个阶段影响这些细胞，这些细胞是如何在胎盘发育的每个阶段中生长的？ 细胞缺陷与特定的妊娠结局相关（目的2），以及VEGF信号传导的位置和时间 可以针对这些途径采取预防和治疗策略（目标2）。一些新的技术将 用于解决这些问题，包括诱导胎盘和蜕膜特异性基因表达系统 用于精确控制妊娠不连续阶段的基因表达，以及纳米颗粒介导的 胎盘中的特定细胞。最后，我们的初步数据表明，类似的EVT可能是 在人类胎盘中存在与小鼠中TGC相似的位置，并且VEGF可能在人胎盘中起类似的作用。 人滋养层分化我们将使用激光来表征人类胎盘中EVT的多样性 人绒毛膜滋养层祖细胞的显微切割、整体转录谱分析和培养模型 细胞分化（目标3）。这些研究将描述以前未被重视的关系， 过度的VEGF信号传导和错误的滋养层分化以及由此产生的妊娠疾病谱 并为这些疾病的诊断和靶向治疗的发展提供具体指导。

Every year over 300,000 women die from pregnancy complications, and over 6.5 million more suffer complications that result in life-long disability, for which $41 billion is spent on healthcare costs. However, little is known about the development and differentiation of the cells—extravillous trophoblasts (EVTs)—at the heart of most human pregnancy complications. Our overarching goal is to develop mechanism-based strategies to prevent, diagnose, and treat pregnancy complications associated with faulty trophoblast development. We have strong evidence that vascular endothelial growth factor (VEGF) acts directly on trophoblast stem cells and plays a key role in the differentiation of junctional zone cells and specific subtypes of trophoblast giant cells (TGCs) in mice, which are orthologous to EVTs in humans. We discovered that different levels of decidual VEGF overexpression at the implantation site stimulates placental production of the potent endogenous VEGF antagonist soluble fms-like tyrosine kinase 1 (sFlt1) and induces a spectrum of symptoms in mice similar to those of human obstetrical diseases, from preeclampsia to abruptio placentae. Our preliminary data show that specific symptoms of each of those diseases are associated with abnormal development of a subset of TGCs and junctional zone cells. Thus, we hypothesize that the level of VEGF overexpression during early placental development corresponds to abnormal development of specific subtypes of TGCs associated with distinct pregnancy complications and that the diseases associated with excess sFlt1 production can be treated by reducing sFlt1 only at later stages of pregnancy. We also hypothesize that different EVT subtypes exist and that excess VEGF can cause disproportionate expansion of specific EVT subtypes in humans. Thus, our experiments will define the role of VEGF in the development of specific trophoblast subtypes (Aim 1), how levels of VEGF affect these cells at each stage of placental development in vivo in the mouse, how these cellular defects are related to specific pregnancy outcomes (Aim 2), and where and when VEGF signaling pathways can be targeted for prevention and therapeutic strategies (Aim 2). Several novel techniques will be used to address these questions, including inducible placenta- and decidua-specific gene expression systems for precise control of gene expression at discrete stages of pregnancy, and nanoparticle-mediated delivery of morpholinos to specific cells in the placenta. Finally, our preliminary data suggest that analogous EVTs may be present at similar locations in the human placenta as TGCs in mice and that VEGF may play a similar role in human trophoblast differentiation. We will characterize the diversity of EVTs in human placenta using laser microdissection, global transcriptional profiling, and a culture model of human chorionic trophoblast progenitor cell differentiation (Aim 3). These studies will characterize the previously unappreciated relationship between excess VEGF signaling and faulty trophoblast differentiation and the resulting spectrum of pregnancy disorders and provide specific guidance for the development of diagnostics and targeted therapies for these disorders.