ATF6 is Required for ANP Secretion from the Heart

ATF6 是心脏分泌 ANP 所必需的

• 批准号: 10219762
• 负责人: Chris Glembotski
• 金额: $ 34.54万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-12-15 至 2022-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10219762
• 关键词: ATF6 gene; Acute; Address; Adult; Affect; Antioxidants; Atrial Natriuretic Factor; Biological Models; Blood Pressure; Blood Volume; Calcium; Cardiac; Cardiac Myocytes; Cardiovascular Physiology; Cardiovascular system; Cell Nucleus; Cell membrane; Cells; Cessation of life; Chronic; Cleaved cell; Coupled; Cytoplasmic Granules; Data; Development; Docking; Elements; Ensure; Excretory function; Foundations; Gene Deletion; Gene Expression; Genes; Goals; Golgi Apparatus; Growth Factor Receptors; Heart; Heart Atrium; Heart failure; Hormone secretion; Hormones; Hypertension; Ion Channel; Ischemia; Link; Mammalian Cell; Mission; Modeling; Morbidity - disease rate; Mus; Muscle Cells; Organ; Oxidative Stress; Pathologic; Pathway interactions; Plasma; Play; Proteins; Public Health; Quality Control; Research; Role; Rough endoplasmic reticulum; Route; SNAP receptor; SNAP23 gene; Secretory Vesicles; Site; Stretching; Time; Tissues; Transgenic Mice; United States National Institutes of Health; Vasodilation; Ventricular; base; cardiovascular effects; cell type; design; dietary; endoplasmic reticulum stress; gain of function; hemodynamics; in vivo; innovation; loss of function; misfolded protein; mortality; mouse model; novel; novel strategies; novel therapeutics; peptide hormone; pressure; programs; protein folding; protein function; protein misfolding; salt sensitive hypertension; small molecule; transcription factor; transcriptome

Project Summary ER protein misfolding is sensed in the rough ER by ATF6, which is expressed in all mammalian cells. We previously showed that in ventricular myocytes, in vivo, ischemia causes ER protein misfolding, which is sensed by ATF6, converting it to a transcription factor that induces antioxidant genes that were not known to be ATF6-regulated in any cell type. Our objective here is to study a new role for ATF6 as a critical element in regulated secretion, focusing on atrial natriuretic peptide (ANP), a peptide hormone made in the ER of atrial myocytes. Neither the function of ATF6 in the atria, nor its role in regulated hormone secretion has been studied. Therefore, this proposal addresses a novel role for ATF6 as a linchpin in regulated hormone secretion using a cardiac model system that we call the ATF6-ANP axis. Our preliminary data showed that under non- stressed conditions, in contrast to ventricular cell and tissue, activated ATF6 was found in atrial cell and tissue, even in the absence of ER stress. While activated ATF6 did not increase ANP gene expression in the atria, it was required for ANP secretion from atrial myocytes. Mechanistically, we found that ATF6 induced several secretory pathway proteins that were not previously known to be ATF6-regulated and have not been studied in the heart, including the SNARE protein, SNAP23. SNAP23 is known to enhance granule docking and secretion in other cell types. Based on this background and preliminary data, our hypothesis is that ATF6 is essential for the secretion and beneficial cardiovascular (CV) effects of ANP. SNAP23 is a mechanistic link between ATF6 and regulated ANP secretion. We will address this hypothesis in three specific aims, which are to: 1- examine the effects of AAV9- and small molecule-based ATF6 gain-of-function, and conditional ATF6 gene deletion maneuvers on ANP secretion from atrial myocytes and mouse hearts, 2-determine how ATF6 gain- and loss-of-function affects plasma ANP and hemodynamic parameters in mouse models of dietary high-salt- induced hypertension and pressure overload-induced heart failure, and 3-define the mechanistic role of the ATF6-inducible secretory granule docking protein, SNAP23, in ANP secretion from cultured atrial myocytes and mouse hearts.

项目摘要 ER蛋白的错误折叠在粗糙ER中被在所有哺乳动物细胞中表达的ATF 6感知。我们 先前的研究表明，在体内心室肌细胞中，缺血导致ER蛋白错误折叠， 由ATF 6感知，将其转化为转录因子，诱导抗氧化基因，这些基因不知道 在任何细胞类型中被ATF 6调节。我们的目标是研究ATF 6作为一种关键元素的新作用， 调节分泌，重点是心房钠尿肽（ANP），一种在心房肌ER中产生的肽类激素 肌细胞ATF 6在心房中的功能及其在调节激素分泌中的作用均不清楚。 研究了因此，这一提议提出了ATF 6作为调节激素分泌的关键的新作用 使用心脏模型系统，我们称之为ATF 6-ANP轴。我们的初步数据显示，在非- 在应激条件下，与心室细胞和组织相反，在心房细胞和组织中发现激活的ATF 6， 即使在没有ER应激的情况下。虽然激活的ATF 6并不增加心房ANP基因的表达， 是心房肌细胞分泌ANP所必需的。从机制上讲，我们发现ATF 6诱导了几个 分泌途径蛋白，以前不知道是ATF 6调节的，也没有研究过， 包括SNARE蛋白SNAP 23。已知SNAP 23增强颗粒对接和分泌 其他细胞类型。基于这一背景和初步数据，我们的假设是ATF 6是必不可少的 ANP的分泌和有益的心血管（CV）作用。SNAP 23是一个机械链接， ATF 6和调节ANP分泌。我们将在三个具体目标中讨论这一假设，即：1- 检查基于AAV 9和小分子的ATF 6功能获得性和条件性ATF 6基因的作用 心房肌细胞和小鼠心脏ANP分泌的删除策略，2-确定ATF 6如何获得- 和功能丧失影响高盐饮食小鼠模型的血浆ANP和血流动力学参数， 诱导的高血压和压力超负荷诱导的心力衰竭，和3-定义的机制作用， 心房肌细胞分泌心钠素过程中ATF 6诱导的分泌颗粒对接蛋白SNAP 23的表达 和老鼠的心脏