Flow sensation by kidney cells

肾细胞的血流感觉

基本信息

批准号：
9043873
负责人：
Takanari Inoue
金额：
$ 38.04万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-15 至 2018-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9043873
关键词：
Acetylesterase Automobile Driving Body Fluids Calcium ion Calmodulin Canis familiaris Chemicals Cilia Complex Cues Cyclic AMP-Dependent Protein Kinases Cytosol Developmental Process Diagnostic Dialysis procedure Disease Progression Disease model Enzymes Epithelial Cells Esthesia Event Feedback Goals Growth Hereditary Disease Image Imagery Individual Kidney Kidney Transplantation Length Life Maps Measures Mechanics Membrane Molecular Mus Nutrient Occupations Patients Phosphotransferases Physiological Play Polycystic Kidney Diseases Property Proteins Regulation Renal function Research Resolution Resort Role Sensory Series Signal Transduction Signaling Molecule Site Stress Techniques Technology Testing Time Tissues Urine base collecting tubule structure demographics desensitization experience extracellular fluid flow genetic manipulation inhibitor/antagonist insight kidney cell kidney epithelial cell loss of function molecular actuator novel physical property pressure public health relevance research study sensor skeletal symptom treatment

Acetylesterase Automobile Driving Body Fluids Calcium ion Calmodulin Canis familiaris Chemicals Cilia Complex Cues Cyclic AMP-Dependent Protein Kinases Cytosol Developmental Process Diagnostic Dialysis procedure Disease Progression Disease model Enzymes Epithelial Cells Esthesia Event Feedback Goals Growth Hereditary Disease Image Imagery Individual Kidney Kidney Transplantation Length Life Maps Measures Mechanics Membrane Molecular Mus Nutrient Occupations Patients Phosphotransferases Physiological Play Polycystic Kidney Diseases Property Proteins Regulation Renal function Research Resolution Resort Role Sensory Series Signal Transduction Signaling Molecule Site Stress Techniques Technology Testing Time Tissues Urine base collecting tubule structure demographics desensitization experience extracellular fluid flow genetic manipulation inhibitor/antagonist insight kidney cell kidney epithelial cell loss of function molecular actuator novel physical property pressure public health relevance research study sensor skeletal symptom treatment

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项目摘要

DESCRIPTION (provided by applicant): The goal of this proposal is to elucidate the molecular mechanism underlying mechanosensation of urine flow by kidney cells. Developmental processes are often driven by body fluid flow which delivers information that is mechanical (shear, drag, pressure) or chemical (nutrients, metabolites, growth factors). In the kidney, the primary cilium, a tiny cellular antenna, represents a specialized platform to sense and integrate such complex information in urine flow. Shear forces from fluid flow activate calcium ion (Ca2+) channels that reside in the ciliary membrane and induce Ca2+-triggered signaling events in the cytosol. Flow sensation plays a critical role in tissue integrity and functions of kidney. However, the mechanism converting extracellular mechanical cues into intraciliary chemical signaling at the molecular and cellular levels remains poorly understood. This is primarily due to a lack of experimental techniques to visualize and manipulate chemical signaling inside primary cilia. Recently, we have developed a series of molecular sensors and actuators that for the first time enabled visualization of ciliary Ca2+ signaling and rapid perturbation of ciliary structural components, respectively. Based on the bending profile of primary cilia upon flow administration, we hypothesize that the base of cilia experience a large stress such as membrane tension and compression which opens mechanosensitive Ca2+ channels to initiate the Ca2+ signaling in this region. To test this, we will visualize flow-induced Ca2+ signaling at a high resolution in space and time, which will be leveraged by the developed molecular sensors whereby Ca2+ dynamics can be precisely mapped within the primary cilia of kidney cells. We will then determine structural components that confer the mechanical properties required for flow sensation using conventional as well as our newly developed molecular actuators. Ca2+ signaling also regulates the physical properties of the cilium, suggesting a feedback regulation in the form of desensitization. Therefore, we will investigate how flow-induced Ca2+ signaling modulates the physical properties of the primary cilium. We will then extend this study to polycystic kidney disease (PKD), which manifests an inability of kidney cells to properly sense the urine flow. In particular, we will determine the mechanosensation steps impaired in the PKD kidney cells with an aim to obtain insights into the PKD progression mechanism. For experiments, we will use kidney collecting duct epithelial cells from mice (mIMCD3) and dogs (MDCK) with or without genetic manipulation of PKD1 and/or PKD2.

描述（由申请人提供）：该提案的目的是阐明肾细胞对尿液流动的分子机制。发育过程通常是由体液流动驱动的，体液流量提供了机械（剪切，阻力，压力）或化学（营养，代谢物，生长因子）的信息。在肾脏中，主要的纤毛是一种微小的细胞天线，代表了一个专门的平台，可以在尿液流中感知和整合此类复杂信息。流体流的剪切力激活钙离子（Ca2+）通道，该通道位于睫状膜中，并在细胞质中诱导Ca2+触发的信号传导事件。流动在组织完整性和肾脏功能中起关键作用。然而，将细胞外机械提示转化为分子和细胞水平上的内化学信号传导的机制仍然很少了解。这主要是由于缺乏可视化和操纵原发性纤毛内化学信号的实验技术。最近，我们开发了一系列分子传感器和执行器，这些传感器和执行器首次能够可视化纤毛Ca2+信号传导和纤毛结构成分的快速扰动。基于原发性纤毛的弯曲曲线，我们假设纤毛的底部经历了巨大的应力，例如膜张力和压缩，这打开了机械敏感的Ca2+通道，以在该区域启动Ca2+信号传导。为了测试这一点，我们将可视化流动诱导的Ca2+信号传导空间和时间上的高分辨率将由发达的分子传感器利用，从而可以精确地将Ca2+动力学映射到肾细胞的一级纤毛中。然后，我们将确定使用常规以及我们新开发的分子致动器所需的机械性能赋予流动感觉所需的机械性能。 Ca2+信号传导还调节了纤毛的物理特性，表明反馈调节以脱敏形式。因此，我们将研究流动诱导的Ca2+信号传导如何调节原代纤毛的物理特性。然后，我们将将这项研究扩展到多囊性肾脏疾病（PKD），这表明肾细胞无法正确感知尿液的流动。特别是，我们将确定PKD肾脏细胞中受损的机械敏步骤，以了解对PKD进程机理的见解。对于实验，我们将使用来自PKD1和/或PKD2的有或没有遗传操作的小鼠（MIMCD3）和狗（MIMCD3）和狗（MDCK）的肾脏上皮细胞。