VEGF signaling in placental development and disease

每年有30多万妇女死于妊娠并发症，另有超过650万妇女遭受 导致终身残疾的并发症，为此花费了410亿美元的医疗费用。然而，几乎没有 已知心脏细胞-绒毛外滋养层细胞(EVT)的发育和分化 在大多数人类妊娠并发症中。我们的总体目标是制定基于机制的战略，以 预防、诊断和治疗与滋养细胞发育不良相关的妊娠并发症。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 在巨型滋养细胞交界区细胞和特定亚型的分化中起关键作用。 小鼠的细胞(TGC)，与人类的EVT同源。我们发现不同水平的蜕膜 着床部位血管内皮生长因子过表达刺激胎盘产生强大的内源性血管内皮生长因子 拮抗剂可溶性FMS样酪氨酸激酶1(SFlt1)，并在小鼠中引起类似于 人类产科疾病，从先兆子痫到胎盘早剥。我们的初步数据显示， 每种疾病的特定症状都与TGC子集的异常发育有关 和交界区细胞。因此，我们推测，在胎盘早期，血管内皮生长因子的过度表达水平 发育对应于与不同类型的TGC相关的特定亚型的异常发育 妊娠并发症和与sFlt1过度产生相关的疾病可以通过以下方法治疗 仅在妊娠后期降低sFlt1。我们还假设存在不同的EVT亚型 过量的血管内皮生长因子可导致人类特定的EVT亚型不成比例的扩大。因此，我们的 实验将确定血管内皮生长因子在特定滋养层亚型发育中的作用(目标1)，如何 在小鼠体内胎盘发育的每个阶段，血管内皮生长因子的水平如何影响这些细胞？ 细胞缺陷与特定的妊娠结局有关(目标2)，以及何时何地传递血管内皮生长因子信号 路径可作为预防和治疗战略的目标(目标2)。几项新技术将被 用于解决这些问题，包括可诱导的胎盘和蜕膜特异性基因表达系统 用于精确控制怀孕不同阶段的基因表达，以及纳米颗粒介导的 胎盘中特定细胞的吗啡肽。最后，我们的初步数据表明，类似的EVT可能是 在人类胎盘中与小鼠的TGCs存在相似的位置，并且VEGF可能在 人滋养层细胞分化。我们将使用激光来表征人胎盘中EVT的多样性 显微解剖、整体转录图谱和人绒毛膜滋养层祖细胞的培养模型 细胞分化(目标3)。这些研究将描述以前未被认识到的 过度的血管内皮生长因子信号和滋养层细胞分化缺陷以及由此导致的妊娠紊乱 并为这些疾病的诊断和针对性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.