Wnt5a and Planar Cell Polarity in Kidney Development and Cyst formation

Wnt5a 和平面细胞极性在肾脏发育和囊肿形成中的作用

• 批准号: 8694353
• 负责人: Liwei Huang
• 金额: $ 12.97万
• 依托单位: EASTERN VIRGINIA MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-15 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8694353
• 关键词: Adult; Affect; American; Animal Model; Apical; Autosomal Dominant Polycystic Kidney; Autosomal Recessive Polycystic Kidney; Cell Polarity; Cell model; Cell physiology; Cells; Chromosome Mapping; Cilia; Complex; Cyst; Cystic Kidney Diseases; Cystic kidney; Development; Disease; Drosophila genus; Embryo; Epithelial; Epithelial Cells; Epithelium; Family; Gene Activation; Gene Expression; Gene Proteins; Genes; Glycoproteins; Goals; Hereditary Disease; Homeostasis; Human; In Vitro; Kidney; Knock-out; Link; Liquid substance; Locales; Location; MAPK8 gene; MDCK cell; Measures; Membrane Proteins; Mentors; Messenger RNA; Modeling; Molecular; Mus; Nuclear; Organ; Organelles; Pathogenesis; Pathway interactions; Pattern; Phenotype; Play; Proliferating; Proteins; Regulation; Renal tubule structure; Research Project Grants; Role; Secretory Component; Sensory; Signal Pathway; Signal Transduction; Signaling Molecule; Surface; Testing; Therapeutic Intervention; Time; Tissues; Tubular formation; Vesicle; Wnt proteins; Work; cilium biogenesis; design; functional group; in vivo; nephrogenesis; novel; overexpression; receptor; research study; rho GTP-Binding Proteins; trans-Golgi Network

DESCRIPTION (provided by applicant): Cysts are "building blocks" for epithelial organs, such as the kidney, and abnormal regulation of cystogenesis results in disorders such as autosomal dominant polycystic kidney disease (ADPKD). ADPKD, affecting 500,000 Americans, is the most common potentially lethal genetic disease. The primary cilium, an organelle projecting from the apical surface, has been strongly implicated in ADPKD pathogenesis and is thought to act as a sensory antenna that transmits information regarding flow dynamics to the cell. When primary cilia of renal tubule cells are disrupted, the cells, through a still unclear mechanism, misinterpret this as a signal to dedifferentiate and proliferate, resulting in the formation of lare cysts that destroy the kidney. The goal here is to understand the role of the highly conserved eight-protein exocyst complex in kidney development, especially how the exocyst interacts with Wnt proteins. The exocyst is a critical component of the secretory pathway, shuttling vesicles containing membrane proteins from the trans-Golgi network to targeted subcellular locales, including primary cilia. Sec10, in turn, is a critical component of the exocyst. The Lipschutz Lab (the mentor's lab) has shown through in vitro studies of renal tubule cells that Sec10 is critical for proper formation of both primary cilia and cysts. In addition, it was shown in human ADPKD cells that the exocyst is mislocalized intracellularly, thereby establishing a link between exocyst location and ADPKD. Wnt genes encode a large, highly conserved family of secreted glycoproteins that play essential roles in controlling tissue patterning, cell fate, and proliferaton from drosophila to humans. Vertebrate Wnts have been divided into two functional groups by reference to their downstream signaling pathways. The canonical Wnts signal through nuclear 2-catenin/TCF-LEF while the noncanonical Wnts function through alternate signaling cascades that include Ca2+/PKC and RhoA/JNK. The canonical Wnt pathway is necessary for adult kidney homeostasis, and abrogation of this signaling leads to cystic kidney disease. The Lipschutz Lab showed that Rho GTPases regulate the exocyst, and Preliminary Studies show Wnt and exocyst mRNA co-expression during kidney development, as well as differential Wnt expression following Sec10 knockdown in vitro. The hypothesis we propose testing is that Wnt genes work with the exocyst to regulate kidney development, especially ciliogenesis and cystogenesis. Accordingly, we will use embryonic mouse kidneys to examine spatial-temporal exocyst and Wnt expression patterns during development (Aim 1). We will then use in vitro renal epithelial cell models to characterize the molecular pathways by which the exocyst and Wnts interact (Aim 2). Finally, we will study the role of the exocyst in regulating kidney development and Wnt signaling in vivo utilizing kidney- specific Sec10-overexpressing, Sec10 knockout, and Pkd2WS25/WS183 mice, representing an outstanding animal model of ADPKD (Aim 3). Successful completion of these experiments will result in the identification of novel candidate targets for therapeutic intervention in ADPKD, a disease for which no approved treatments exist.

描述（由申请人提供）：囊肿是上皮器官（例如肾脏）的“基础”，囊肿性异常调节导致疾病，例如常染色体显性多囊肾脏疾病（ADPKD）。影响50万美国人的ADPKD是最常见的致命遗传疾病。主要的纤毛是一种从顶部表面投射的细胞器，已与ADPKD发病机理有很大的影响，并被认为是将有关流动动力学传输到细胞的信息传递信息的感觉天线。当肾小管细胞的原发性纤毛被破坏时，通过仍然不清楚的机制，细胞将其误解为去分化和增殖的信号，从而形成了破坏肾脏的Lare囊肿。 这里的目的是了解高度保守的八蛋白外囊肿复合物在肾脏发育中的作用，尤其是外囊肿如何与Wnt蛋白相互作用。外囊肿是分泌途径的关键组成部分，将含有膜蛋白的囊泡从反式高尔基网络到靶向亚细胞的囊泡（包括原发性纤毛）。 SEC10反过来是外囊肿的关键组成部分。 Lipschutz Lab（导师实验室）通过对肾小管细胞的体外研究表明，SEC10对于正确形成原代纤毛和囊肿至关重要。此外，在人ADPKD细胞中表明，外囊肿是细胞内错误定位的，从而建立了外囊肿之间的联系 位置和ADPKD。 Wnt基因编码了一个高度保守的分泌糖蛋白家族，该家族在控制组织模式，细胞命运和从果蝇到人类的增殖中起着至关重要的作用。脊椎动物WNT已通过参考下游信号通路将两个功能组分为两个功能组。经典的WNT通过核2-catenin/tcf-lef信号，而非规范WNT通过包括Ca2+/PKC和RhoA/JNK在内的替代信号级联函数。典型的WNT途径对于成年肾脏稳态是必需的，并且废除该信号会导致囊性肾脏疾病。 Lipschutz实验室表明，Rho GTPases调节外旋囊肿，初步研究表明，肾脏发育过程中的Wnt和cyocyst mRNA共表达以及在体外SEC10敲低后的差异Wnt表达。我们提出的测试的假设是，Wnt基因与胞外囊肿起作用以调节肾脏发育，尤其是纤毛生成和膀胱遗传学。因此，我们将使用胚胎小鼠肾脏检查发育过程中的时空外囊肿和Wnt表达模式（AIM 1）。然后，我们将使用体外肾上皮细胞模型来表征外囊肿和WNT相互作用的分子途径（AIM 2）。最后，我们将研究外囊肿在调节肾脏发育和Wnt信号传导中的作用，利用肾脏特异性SEC10超过表达SEC10敲除和PKD2WS25/WS183小鼠，代表ADPKD的杰出动物模型（AIM 3）。这些实验的成功完成将导致确定在ADPKD中进行治疗干预的新型候选靶标，该疾病不存在批准的治疗方法。