Shroom3 in nephron formation

我的研究计划的长期重点是确定肾脏发育的基本机制。肾脏由数以百万计的肾单位组成，它们过滤血液并重新吸收离子、蛋白质和水。这使得肾元对几乎所有多细胞生物的体内平衡至关重要。肾元的正常发育是肾元正常功能的基本要求。当松散堆积的肾元祖间质（NPM）细胞紧密聚集，改变其形态并向上皮细胞过渡时，肾元形成开始。通过广泛的形态发生，这些结构经过不同的阶段形成肾元。NPM细胞的正确聚集、组织和形态发生对于为肾元功能奠定适当的基础至关重要，但对这些过程的调节机制知之甚少。Shroom3是一种肌动蛋白结合蛋白，在发育中的上皮细胞如肠、眼和神经管中调节细胞形态发生。尽管细胞形态发生对肾脏发育的重要性和大量证据表明Shroom3与肾功能不良有关，但Shroom3在肾脏中作用的基本机制尚不清楚。我们发表的数据表明，成年Shroom3突变小鼠具有由无序上皮组成的功能不良的肾单位。我们未发表的数据表明，Shroom3在NPM中表达，2)是NPM组织所必需的，3)是聚集和肾小泡形成所必需的。这些数据为我们提供了对NPM细胞聚集和肾元模式所需的细胞形态发生机制产生新见解的机会。利用我们新生成的Shroom3条件小鼠模型，我们将在我们令人兴奋的发现的基础上，剖析Shroom3调节NPM聚集和肾元形成的细胞机制。在本提案中，我们将通过执行目标1：确定Shroom3对NPM细胞形态和NPM转录组的影响2)确定Shroom3调节肾元祖细胞形态的机制并定义Shroom3蛋白相互作用组，为我们的长期目标做出贡献。该计划将确定Shroom3在肾元祖细胞形态调节中的作用，确定形态变化如何影响细胞通讯，并确定Shroom3的上下游调节剂。这些研究也将扩展我们对肾脏发育过程中肾素祖细胞形成和模式的理解。此外，这些研究将扩展我们对Shroom3在细胞和组织形态发生机制的理解，并将为未来的研究提供重要的知识。此外，这些研究还将进一步了解为什么Shroom3与肾功能差有关，并解决儿童肾衰竭最常见的原因——肾脏发育异常的问题。

The long-term focus of my research program is to define the fundamental mechanisms of kidney development. Kidneys are composed of millions of nephrons that filter the blood and reabsorb ions, proteins, and water. This makes the nephron essential for homeostasis in virtually every multicellular organism. The proper development of the nephron is a fundamental requirement for proper nephron function. Nephron formation begins when loosely packed nephron progenitor mesenchyme (NPM) cells tightly cluster, alter their morphology, and transition to epithelia. Through extensive morphogenesis these structures progress through various stages to form the nephron. The correct clustering, organizing, and morphogenesis of the NPM cells is essential for setting the proper foundation for nephron function, yet little is known about the mechanisms regulating these processes. Shroom3 is an actin binding protein that regulates cell morphogenesis in developing epithelial such as the gut, eye, and neural tube. Despite the importance of cell morphogenesis for kidney development and significant evidence that Shroom3 is associated with poor kidney function, the fundamental mechanisms of Shroom3's actions in the kidney is lacking. Our published data demonstrates that adult Shroom3 mutant mice have poorly functioning nephrons composed of disorganized epithelia. Our unpublished data demonstrates that Shroom3 is 1) expressed in the NPM, 2) is required for NPM organization, 3) is required for clustering and renal vesicle formation. This data provides us with the opportunity to generate novel insights into the cellular morphogenetic mechanisms required for NPM cell clustering and patterning of the nephron. Using our newly generated Shroom3 conditional mouse model we will build on our exciting findings and dissect the cellular mechanisms by which Shroom3 regulates NPM aggregation and nephron formation. In this proposal we will contribute to our long-term goal by performing objective 1: Determine the effects of Shroom3 on the NPM cell morphology and the NPM transcriptome 2) Define the mechanisms by which shroom3 modulates nephron progenitor morphology and defining the Shroom3 protein interactome. The proposed plan will determine the contribution of Shroom3 in the regulation of nephron progenitor cell morphology, identify how morphological changes affect cellular communication, and identify up and down stream modulators of Shroom3. These studies will also extend our understanding of nephron progenitor formation and patterning during kidney development. Further, these studies will extend our understanding of Shroom3 mechanisms in cell and tissue morphogenesis and will contribute significant knowledge for future research. In addition, these studies will also provide further understanding as to why Shroom3 is associated with poor kidney function and address questions as to the most common cause of childhood kidney failure, which is abnormal kidney development.