A K63-Ubiquitination Dependent Necroptosis Signaling Network in the Heart

心脏中 K63 泛素化依赖性坏死性凋亡信号网络

• 批准号: 10543111
• 负责人: Qinghang Liu
• 金额: $ 38.88万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-08 至 2025-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10543111
• 关键词: Ablation; Acute; Adult; Apoptosis; Attenuated; Biological; Cardiac; Cardiac Myocytes; Caspase; Cell Death Signaling Process; Cell membrane; Cessation of life; Complex; Data; Dilated Cardiomyopathy; Disease; Enzymes; Gene Transfer; Genetic; Goals; Heart; Heart Injuries; Heart failure; Inflammation; Investigation; Ischemia; Link; MAP3K7 gene; Mediating; Mitochondria; Modeling; Molecular; Mus; Myocardial; Myocardial Ischemia; Necrosis; Organelles; Pathologic; Pathway interactions; Phosphorylation; Physiology; Pilot Projects; Play; Polyubiquitination; Process; RIPK1 gene; RIPK3 gene; Regulation; Reperfusion Injury; Role; Signal Transduction; Swelling; TNF receptor-associated factor 2; TNFRSF1A gene; Testing; Therapeutic; Ubiquitination; cardioprotection; experimental study; gain of function; in vivo; insight; ischemic injury; loss of function; myocardial injury; novel; overexpression; prevent; receptor; therapeutic target; ubiquitin isopeptidase; ubiquitin ligase; ubiquitin-protein ligase; vector

Project Summary/Abstract Loss of cardiomyocytes by apoptosis and/or necrosis is a hallmark of cardiac ischemic injury, pathological remodeling, and end-stage heart failure. Although necrosis was traditionally regarded as a passive and unregulated process, emerging evidence has shifted this paradigm and identified several forms of “programmed necrosis”, including death receptor-mediated necrosis (termed “necroptosis”), mitochondria-mediated necrosis, and other regulated necrotic processes. Despite recent progress, how necroptosis is regulated in the heart remain largely unknown and preventing necroptotic cardiomyocyte death is still an important challenge. Our pilot studies identified a new K63-linked polyubiquitination (K63-Ub) dependent necroptosis signaling network that critically regulates cardiac ischemic injury and pathological remodeling. Intriguingly, the K63-deubiquitinase CYLD (cylindromatosis) was markedly up-regulated, whereas the E3 ubiquitin ligase TRAF2 (TNF receptor associated factor-2) was down-regulated, in the heart after ischemia-reperfusion injury. Our preliminary results further identified CYLD and TRAF2 as an activator and a suppressor of myocardial necroptosis, respectively. Importantly, cardiomyocyte-specific ablation of CYLD attenuated ischemic injury and adverse remodeling by inhibiting necroptosis. Acute deletion of TRAF2 in the adult heart caused dilated cardiomyopathy by promoting necroptosis, whereas TRAF2 gene transfer elicited cardioprotection. Mechanistically, we propose a new K63- Ub dependent necroptotic regulatory mechanism whereby CYLD deubiquitinates TRAF2 and TAK1, disrupts TAK1-RIP1 interaction, and promotes the necroptotic complex. As an opposing mechanism, TRAF2 acts as an E3 ligase for TAK1 to inhibit necroptosis signaling. Thus, the reversible K63-Ub (mainly non-proteolytic) constitutes a new paradigm of necroptosis signaling with important biological implications. We hypothesize that the deubiquitinase CYLD, in conjunction with the E3 ligase TRAF2, critically regulate myocardial necroptosis, ischemic injury, and remodeling, thus representing promising therapeutic targets. Aim 1 will investigate the opposing roles of K63-Ub modifying enzymes CYLD and TRAF2 in regulating myocardial necroptosis and ischemic injury in vivo. Aim 2 will define a CYLD/TRAF2 mediated, K63-Ub dependent necroptosis signaling network in cardiomyocytes. Using genetic and molecular strategies, we will investigate the opposing roles of CYLD and TRAF2 in regulating myocardial necroptosis under basal conditions and in the setting of ischemic injury. The proposed studies will provide new insights into the molecular regulation and functional significance of necroptosis in the heart, which has important translational implications, especially given our preliminary results revealing CYLD/TRAF2 as key necroptotic regulators and promising targets for ischemic heart disease.

项目概要/摘要 心肌细胞因凋亡和/或坏死而损失是心脏缺血性损伤、病理性损伤的标志。 重构和终末期心力衰竭。尽管坏死传统上被认为是一种被动的、 不受监管的过程，新出现的证据已经改变了这种范式，并确定了几种形式的“程序化” 坏死”，包括死亡受体介导的坏死（称为“坏死性凋亡”）、线粒体介导的坏死， 和其他受调节的坏死过程。尽管最近取得了进展，但坏死性凋亡在心脏中是如何调节的 仍然很大程度上未知，预防坏死性心肌细胞死亡仍然是一个重要的挑战。我们的飞行员 研究发现了一个新的 K63 连接的多聚泛素化 (K63-Ub) 依赖性坏死性凋亡信号网络 关键调节心脏缺血性损伤和病理重塑。有趣的是，K63-去泛素酶 CYLD（圆柱瘤病）显着上调，而 E3 泛素连接酶 TRAF2（TNF 受体） 缺血再灌注损伤后心脏中相关因子2）下调。我们的初步结果 进一步确定 CYLD 和 TRAF2 分别是心肌坏死性凋亡的激活剂和抑制剂。 重要的是，CYLD 的心肌细胞特异性消融减轻了缺血性损伤和不良重塑 抑制坏死性凋亡。成人心脏中 TRAF2 的急性缺失通过促进 坏死性凋亡，而 TRAF2 基因转移则引发心脏保护作用。从机制上来说，我们提出了一种新的 K63- Ub 依赖性坏死性凋亡调节机制，CYLD 使 TRAF2 和 TAK1 去泛素化，破坏 TAK1-RIP1相互作用，促进坏死性凋亡复合物。作为一种对抗机制，TRAF2 充当 TAK1 的 E3 连接酶可抑制坏死性凋亡信号传导。因此，可逆的 K63-Ub（主要是非蛋白水解的） 构成了具有重要生物学意义的坏死性凋亡信号传导的新范例。我们假设 去泛素酶 CYLD 与 E3 连接酶 TRAF2 结合，关键地调节心肌坏死性凋亡， 缺血性损伤和重塑，因此代表了有希望的治疗靶点。目标 1 将调查 K63-Ub 修饰酶 CYLD 和 TRAF2 在调节心肌坏死性凋亡中的相反作用 体内缺血性损伤。目标 2 将定义 CYLD/TRAF2 介导的 K63-Ub 依赖性坏死性凋亡信号传导 心肌细胞中的网络。使用遗传和分子策略，我们将研究相反的作用 CYLD 和 TRAF2 在基础条件下和缺血环境下调节心肌坏死性凋亡 受伤。拟议的研究将为分子调控和功能意义提供新的见解 心脏坏死性凋亡，这具有重要的转化意义，特别是考虑到我们的初步结果 揭示 CYLD/TRAF2 作为关键的坏死性凋亡调节因子和缺血性心脏病的有希望的靶点。