Role of Neuregulin/erbB Signaling in the Adult Heart

神经调节蛋白/erbB 信号在成人心脏中的作用

• 批准号: 7281493
• 负责人: Douglas B Sawyer
• 金额: $ 23.77万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-30 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7281493
• 关键词: biological signal transduction; cardiac myocytes; cell differentiation; cell growth regulation; cytoprotection; endopeptidases; enzyme activity; focal adhesion kinase; growth factor receptors; heart failure; heart ventricle; laboratory rat; molecular chaperones; myocardium; neuregulins; oxidative stress; protein isoforms; protein tyrosine kinase; sarcomeres; tissue /cell culture; ubiquitin; vascular endothelium

DESCRIPTION (provided by applicant): The importance of Neuregulin (NRG) and the erbB2 and erbB4 receptor tyrosine kinases in the heart is well established. Gene deletion experiments in mice have demonstrated that neuregulin-1, erbB2, and erbB4 are required for cardiac development. Conditional knockout of erbB2 demonstrates that this signaling system is required for postnatal cardiac growth and maintenance of normal cardiac structure and function. Clinical cardiotoxicity of the erbB2 antibody-based compound trastuzumab can be interpreted as a demonstration that this system is required for cardiac response to injury, or repair. The goal of this research program has been to use a cellular and molecular approach to understand in detail the mechanisms by which NRG/erbB signaling functions to regulate myocardial structure and function. In the initial funding period we have demonstrated that cardiac microvascular endothelial cells express a complex array of NRG-1 isoforms, primarily as transmembrane proteins. We have further demonstrated that the NRG-1beta isoform is activated by conditions of oxidative stress and protects cardiac myocytes against several myocytotoxic stressors. Our central hypothesis is that activation of myocardial neuregulin/erbB signaling is dynamically regulated to maintain cardiac structure and function in the setting of stress. This hypothesis will be approached through 3 Specific Aims. Aim 1 will focus on the regulation of NRG activation by proteolytic processing in microvascular endothelial cells. Aim 2 will focus on how cellular chaperones and ubiquitination enzymes regulate erbB2 and erbB4 receptor stability in cardiac myocytes, and therefore NRG responsiveness. Aim 3 will examine how NRG regulates myocyte structure, focusing on the role of a specific src/FAK pathway that we have recently identified downstream of the erbB2 receptor. Ultimately, these studies will lead to an understanding of how myocardial NRG/erbB signaling functions to positively regulate cardiac structure, function, and response to stress.

描述（由申请人提供）：神经调节蛋白 (NRG) 以及 erbB2 和 erbB4 受体酪氨酸激酶在心脏中的重要性已得到充分证实。小鼠基因缺失实验表明，neuregulin-1、erbB2 和 erbB4 是心脏发育所必需的。 erbB2 的条件敲除表明该信号系统是出生后心脏生长和维持正常心脏结构和功能所必需的。基于 erbB2 抗体的化合物曲妥珠单抗的临床心脏毒性可以解释为证​​明该系统是心脏对损伤或修复的反应所必需的。该研究项目的目标是使用细胞和分子方法来详细了解 NRG/erbB 信号传导调节心肌结构和功能的机制。在最初的资助期间，我们已经证明心脏微血管内皮细胞表达一系列复杂的 NRG-1 亚型，主要是跨膜蛋白。我们进一步证明，NRG-1β亚型在氧化应激条件下被激活，并保护心肌细胞免受多种肌细胞毒性应激源的侵害。我们的中心假设是，心肌神经调节蛋白/erbB 信号传导的激活受到动态调节，以在应激环境下维持心脏结构和功能。这一假设将通过 3 个具体目标来实现。目标 1 将重点关注微血管内皮细胞中蛋白水解过程对 NRG 激活的调节。目标 2 将重点关注细胞伴侣和泛素化酶如何调节心肌细胞中的 erbB2 和 erbB4 受体稳定性，从而调节 NRG 反应性。目标 3 将研究 NRG 如何调节心肌细胞结构，重点关注我们最近在 erbB2 受体下游发现的特定 src/FAK 通路的作用。最终，这些研究将有助于了解心肌 NRG/erbB 信号传导如何发挥积极调节心脏结构、功能和应激反应的作用。