Signaling and Function of the Adrenal Rosette

项目概述：自主性醛固酮产生正在成为一个重要的临床问题。是 不受盐状态或肾素-血管紧张素系统的调节。自主性在原发性醛固酮增多症中很严重， 在低肾素和顽固性高血压中普遍存在，在正常血压中轻微但明显。当 不适合盐的状态，醛固酮促进心血管疾病。这个问题的核心前提是 应用是醛固酮产生细胞的解剖学玫瑰花状组织（Glomerulosa， zG）决定了它们的细胞行为。因此，了解zG细胞的行为是如何 控制的玫瑰花结结构将揭示如何控制自主醛固酮生产， 现在不存在。 之前，我们发现zG细胞在其细胞连接性被破坏时表现为电振荡器。 保持在ROOT内。使用遗传编码的Ca 2+指标，我们已经建立在这一发现的基础上， 提供令人兴奋的初步数据，确定一个潜在的新目标，TRPV 4通道，和一个潜在的 zG细胞激活的新模式，机械激活。我们的总体假设是， 设定zG细胞兴奋性的极限。我们进一步提出，这种TRPV 4活性是由第二个控制的。 信使，机械刺激和钙粘蛋白介导的粘附，从而提供了额外的方式调节 zG细胞行为。 在本提案的目的1中，我们试图确定TRPV 4活性在zG细胞中的电压和Ca 2+振荡中的作用。 细胞使用高速成像工具和所有光学电生理学。在本建议的目标2中，我们力求 确定粘附连接（AJ）如何募集和控制zG细胞之间的协调Ca 2+信号， rooms.我们将以LGR 4/5或ROBO 1/3信号通路为靶点，动态调节细胞周期， AJ复合物（N-钙粘蛋白/β-连环蛋白/α-连环蛋白/黏着斑蛋白/肌动蛋白）的完整性/组成，并评估结果 Ca 2+信号。在本提案的目标3中，我们试图确定粘附连接如何促进自主性 机械激活引起的醛固酮生成以及这些连接如何也增强类固醇生成 对血管紧张素II的敏感性我们测量两个类固醇生成指数：醛固酮和NAD（P）H生成。 该项目将使用先进的高分辨率、落射荧光/共焦成像方法进行 通过基因编码探针，最先进的图像分析和生物化学，分子和 电生理学方法。这项研究有望（1）发现玫瑰花结是如何组织细胞活动的 在zG层内，（2）确定可用于控制的新机制和治疗靶点 醛固酮自主性

Project Summary: Autonomous aldosterone production is emerging as a significant clinical problem. It is not regulated by salt status or the renin-angiotensin system. Autonomy is severe in primary aldosteronism, prevalent in low-renin and resistant hypertension, and subtle but evident in normotension. When inappropriate for salt status, aldosterone promotes cardiovascular disease. The central premise of this application is that the anatomical, rosette-like organization of aldosterone producing cells (zona Glomerulosa, zG) within the adrenal cortex dictates their cellular behavior. Thus, understanding how zG cell behavior is controlled by the rosette structure will reveal ways to control autonomous aldosterone production that at present do not exist. Previously, we discovered that zG cells behave as electrical oscillators when their cellular connectivity is maintained within rosettes. Using genetically encoded Ca2+ indicators, we have built on this discovery and now provide exciting preliminary data identifying one potential new target, the TRPV4 channel, and one potentially new mode for zG cell activation, mechanoactivation. Our overall hypothesis is that TRPV4 activity in rosettes sets the limits of zG cell excitability. We further propose that this TRPV4 activity is controlled by second messengers, mechanical stimuli and cadherin-mediated adhesion, thus providing additional ways of regulating zG cell behavior. In Aim 1 of this proposal we seek to establish the role of TRPV4 activity in voltage and Ca2+ oscillations in zG cells using high speed imaging tools and all optical electrophysiology. In Aim 2 of this proposal we seek to determine how adherens junctions (AJ) recruit and control coordinated Ca2+ signals among zG cells within rosettes. We will target the LGR4/5 or ROBO1/3 signaling pathways to dynamically regulate the integrity/composition of the AJ complex (N-cadherin/β-catenin/α-catenin/vinculin/actin) and assess resulting Ca2+ signals. In Aim 3 of this proposal we seek to determine how adherens junctions facilitate autonomous aldosterone production evoked by mechanoactivation and how these junctions also enhance the steroidogenic sensitivity to Ang II. We measure two steroidogenic indices: aldosterone and NAD(P)H generation. This project will be conducted using advanced, high-resolution, epifluorescence/confocal imaging methods with genetically encoded probes, state-of-the-art image analysis and biochemical, molecular and electrophysiology methods. This research is expected to (1) discover how the rosette organizes cellular activity within the zG layer and, (2) identify new mechanisms and therapeutic targets that can be exploited to control aldosterone autonomy.