PKD1 Signaling and Crosstalk Mechanisms in Intestinal Epithelial Cell Regulation

肠上皮细胞调节中的 PKD1 信号传导和串扰机制

• 批准号: 8915687
• 负责人: JUAN ENRIQUE ROZENGURT
• 金额: $ 33.5万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8915687
• 关键词: Agonist; Biology; Cell Nucleus; Cell Proliferation; Cell Proliferation Regulation; Cells; Cessation of life; Characteristics; Chemicals; Chronic; Complex; DNA biosynthesis; Digestive System Disorders; Disease; Employee Strikes; Epithelial; Epithelial Cell Proliferation; Epithelial Cells; Epithelium; G Protein-Coupled Receptor Signaling; G-Protein-Coupled Receptors; Gastrointestinal tract structure; Growth Factor; Health; In Vitro; Inflammatory; Intestinal Mucosa; Intestines; Knowledge; Laboratories; Link; Lipids; Malignant Neoplasms; Mediating; Membrane; N-terminal; Neurotransmitters; Nuclear; Nuclear Import; Organelles; Organoids; Outcome; Pathogenesis; Pathway interactions; Peptides; Phosphorylation; Play; Process; Protein Kinase; Proteins; Regulation; Role; Signal Transduction; Signal Transduction Pathway; Stem cells; Stimulus; Stratum Basale; System; Testing; Therapeutic Intervention; Transcriptional Activation; Transgenic Mice; Wound Healing; base; cell type; gastrointestinal; human disease; in vivo; innovation; interest; intestinal crypt; intestinal homeostasis; migration; mouse model; novel; p21 activated kinase; protein kinase D; receptor; repaired; response; response to injury; stem

DESCRIPTION (provided by applicant): The sequential proliferation, lineage-specific differentiation, migration and death of the epithelial cells of the intestinal mucosa is a tightly regulated process modulated by a broad range of regulatory peptides, neurotransmitters, bioactive lipids and differentiation signals. Despite its fundamental importance for understanding intestinal homeostasis, wound healing and pathogenesis of human diseases, the signaling mechanisms involved remain incompletely understood. Many gastrointestinal (GI) peptides, neurotransmitters and bioactive lipids initiate their characteristic effects in their target cells through heptahelical G protein-coupled receptors (GPCRs). Protein kinase D (PKD1) is emerging as a key node in GPCR signaling and consequently the understanding of PKD1 regulation and function is of intense interest and potential impact. The studies proposed here will identify new links between GPCR/PKD1 signaling and pivotal pathways that control migration and proliferation of intestinal epithelial cells. The overarching hypothesis to be explored is that PKD1 plays a critical role in the signal transduction pathways leading to intestinal epithelial cell proliferation. Three Specific Aims are proposed: Specific Aim 1: Characterize the role of PKD1 signaling in intestinal epithelial cell proliferation in vivo and in stem cell-derived intestinal organoids. This Aim will focus on PKD1 signaling in vivo, examining its function in homeostatic turnover via stem/progenitor cell proliferation and repair in response to injury of the intestinal mucosa, using genetically modified mouse models, including PKD1 transgenic mice and stem-cell derived intestinal organoids. Specific Aim 2) Characterize crosstalk mechanisms between PKD1 and �-catenin signaling systems in intestinal epithelial cells. The studies proposed in this Aim will characterize an novel crosstalk between GPCR/PKD1 and �-catenin signaling, leading to PKD1/�- catenin complex formation, �-catenin translocation to the nucleus, stimulatory phosphorylation at Ser552 and transcriptional activation; Specific Aim 3) Identify a novel mechanism of PKD1 regulation through PAK-mediated PKD1 phosphorylation at the N-terminal residue Ser203. Based on new preliminary results, we will identify a novel phosphorylation in the N-terminal domain of PKD1 in response to GPCR agonists in intestinal epithelial cells mediated by p21-activated kinases (PAKs), effectors for Rac and Cdc42. The discovery of a PAK/PKD1 cascade uncovers a new point of integration in the signal transduction pathways initiated by GPCR agonists. We anticipate that the mechanistic studies proposed in this application will identify novel upstream pathway(s) and downstream crosstalk mechanisms by which PKD1 regulates the proliferation and migration of intestinal epithelial cells thereby providing the rationale for innovative therapeutic intervention in diseases of the digestive system.

描述（由适用提供）：肠粘膜上皮细胞的顺序增殖，谱系特异性分化，迁移和死亡是一个严格调节的过程，该过程由广泛的调节肽，神经递质，生物活性脂质和分化信号进行了调节。尽管它对于理解人类疾病的肠内稳态，伤口愈合和发病机理的基本重要性，但涉及的信号传导机制仍未完全理解。许多胃肠道（GI）肽，神经递质和生物活性脂质通过甲基甲基G蛋白偶联受体（GPCR）在其靶细胞中启动其特征作用。蛋白激酶D（PKD1）成为GPCR信号传导中的关键节点，因此对PKD1调控和功能的理解具有强烈的关注和潜在影响。这里提出的研究将确定控制肠上皮细胞迁移和增殖的GPCR/PKD1信号传导与关键途径之间的新联系。要探讨的总体假设是，PKD1在导致肠上皮细胞增殖的信号转导途径中起关键作用。提出了三个具体目的：具体目标1：表征体内和干细胞衍生的肠癌中PKD1信号肠上皮细胞增殖的作用。该目标将重点放在体内的PKD1信号传导上，并使用一般修饰的小鼠模型（包括PKD1转基因小鼠和干细胞衍生的肠道类动物）检查了其通过茎/祖细胞增殖和修复对肠粘膜损伤的作用。具体目标2）表征肠上皮细胞中PKD1和`catenin信号系统之间的串扰机制。在此目标中提出的研究将表征GPCR/PKD1和�-catenin信号之间的新串扰，从而导致PKD1/�-catenin络合物形成，`` - - - - - - - - 钙蛋白易位）在Ser552和转录激活中catenin转移到核，刺激性磷酸化；具体目标3）通过N末端住宅Ser203上的PAK介导的PKD1磷酸化来确定PKD1调节的新机制。基于新的初步结果，我们将确定PKD1的N末端结构域的新磷酸化，以响应于P21激活激酶（PAKS）介导的RAC和CDC42的肠道上皮细胞中的GPCR激动剂。 PAK/PKD1级联的发现发现了GPCR激动剂引发的信号转导途径中的新集成点。我们预计，本应用程序中提出的机械研究将确定新型上游途径和下游串扰机制，通过这些机制，PKD1调节了肠上皮细胞的增殖和迁移，从而为消化系统的疾病提供了创新治疗干预的基本原理。