Live imaging analyses of the mechanisms required for coordinated urinary tract peristalsis in lower-order and higher-order mammalian species

低阶和高阶哺乳动物协调尿路蠕动所需机制的实时成像分析

• 批准号: 10181186
• 负责人: Romulo Hurtado
• 金额: $ 3.39万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-03-01 至 2024-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10181186
• 关键词: Ablation; Address; Anatomy; Basic Science; Bladder; Cations; Cells; ChIP-seq; Child; Childhood; Clinical; Defect; Development; Diagnostic; Disease; Distal; Excretory function; Exhibits; Family suidae; Fetus; Flare; Functional disorder; Genes; Genetic Transcription; Goals; Homologous Gene; Human; Hydronephrosis; Image; Imaging Techniques; Immunohistochemistry; Impairment; Injury; Ion Channel; Kidney; Kidney Failure; Mammals; Mediating; Mesenchyme; Metanephric Diverticulum; Morbidity - disease rate; Mus; Muscle; Newborn Infant; Optics; Organ; Pacemakers; Pathology; Pelvis; Peristalsis; Pharmaceutical Preparations; Phenotype; Physiological; Physiology; Play; Procedures; Process; Property; Publishing; Renal Tissue; Reporting; Research; Role; Site; Smooth Muscle; System; Techniques; Testing; Therapeutic; Time; Tissues; Tubular formation; Ureter; Urinary tract; Urine; Video Microscopy; antenatal; clinical translation; clinically significant; human tissue; hyperpolarization-activated cation channel; imaging modality; in vivo; innovation; insight; mouse model; mutant; mutant mouse model; novel; novel therapeutics; patch clamp; pressure; prevent; ratiometric; renal damage; screening; stem cells; transcription factor; wasting

ABSTRACT Proximal-to-distal peristaltic contractions of the upper urinary tract (UUT) smooth muscle coat propel waste from the kidney to the bladder. Defects in the peristaltic process are highly prevalent and clinically significant. For example, impaired urine outflow from the kidney causes pressure mediated dilation of renal tissues, or hydronephrosis. Hydronephrosis is the most commonly observed abnormality in children, detected in 1% of newborns, and is a leading cause of pediatric kidney failure. The overall goal of this project is to better understand the normal physiology and pathophysiology of the UUT. Indeed, despite the high morbidity associated with urinary tract dysfunctions, the mechanisms underlying renal pacemaker activity that triggers UUT peristalsis have remained elusive. To study this process, we have developed novel live imaging techniques to record the propagation of electrical and contractile excitation throughout the intact UUT. Results of our studies have revealed that hyperpolarization activate cation (HCN) channels are highly expressed and localized to renal pacemaker tissues of the murine UUT. HCN channel inhibition abolishes UUT pacemaker activity, and results in a loss of coordinated peristalsis. Instead of the proximal-to-distal contractile and electrical excitation observed in control UUTs, HCN inhibited explants exhibit near-simultaneous electrical activation throughout the UUT and twitch-like contractile activity. Thus, we have demonstrated ex-vivo that HCN+ cells of the UUT are renal pacemakers that set the origin and coordinate UUT peristalsis. Moreover, we have recently discovered that HCN channel expression is conserved to renal pacemaker tissues of the porcine and human urinary tracts, which share a unique anatomy and physiology. In Aim 1 of this proposal we will use a novel mouse model of hydronephrosis that lacks HCN+ cells in the UUT. We will use the live imaging techniques we have developed to determine if loss of HCN+ cells in vivo results in aberrant UUT peristalsis that underlies hydronephrosis. Aim 1 will also include mechanistic studies to begin to elucidate the transcriptional networks regulating HCN+ pacemakers. For Aim 2, we have recently developed a novel explant system to directly visualize the electrical and contractile properties of peristalsis in the porcine UUT. We will use this explant system to determine if HCN channel conductance is required for coordinated UUT peristalsis in a close homolog to humans. Results of these studies will provide much needed insight into the mechanisms underlying normal and aberrant UUT peristalsis in both lower-order and higher-order mammalian species. Long term translational implications of the studies include the development of novel treatments and diagnostics for uropathies such as hydronephrosis.

抽象的 上泌尿道（UUT）平滑肌外套推进浪费 从肾脏到膀胱。蠕动过程中的缺陷非常普遍，并且具有临床意义。 例如，肾脏流出受损会导致压力介导的肾脏组织的扩张，或 肾积水。肾结通是儿童中最常见的异常，在1％中检测到 新生儿，是小儿肾衰竭的主要原因。该项目的总体目标是更好 了解UUT的正常生理和病理生理学。确实，尽管发病率高 与尿路功能障碍相关，这是触发肾脏起搏器活动的机制 Uut Peristalsis仍然难以捉摸。为了研究这一过程，我们开发了新颖的实时成像 在整个完整的UUT中记录电气和收缩激发的传播技术。结果 我们的研究表明，超极化激活阳离子（HCN）通道高度表达，并且 位于鼠UUT的肾脏起搏器组织中。 HCN渠道抑制作用废除了UUT PACEMAKER 活动，并导致蠕动的协调丧失。而不是近端到距离收缩和 在对照UUTS中观察到的电激发，HCN抑制的外植体表现出近相似的电气 在整个UUT和抽搐状的收缩活动中激活。因此，我们已经证明了Ex-Vivo UUT的HCN+细胞是肾脏起搏器，它们设置了原点并坐标UUT Peristalsis。而且，我们 最近发现，HCN通道表达保守了猪的肾脏起搏器组织 和人类尿路，具有独特的解剖学和生理学。在本提案的目标1中，我们将使用 一种新型的肾积水小鼠模型，缺乏UUT中的HCN+细胞。我们将使用实时成像 我们已经开发出来的技术来确定体内HCN+细胞的损失是否导致异常的蠕动 基础肾积水。 AIM 1还将包括机械研究以开始阐明转录 监管HCN+起搏器的网络。对于AIM 2，我们最近开发了一种新颖的外观系统 直接可视化猪UUT中蠕动的电和收缩特性。我们将使用这个 Explant系统，以确定在接近的peristalsis中是否需要HCN通道电导 人类同源。这些研究的结果将提供对基本机制的急需洞察力 低阶和高阶哺乳动物物种中的正常和异常的UUT蠕动。长期 研究的翻译含义包括开发新的治疗方法和诊断。 尿液疾病，例如肾积水。