To explore the potential of UCH-L1 as a novel therapeutic and diagnostic target in heart failure

探索 UCH-L1 作为心力衰竭新治疗和诊断靶点的潜力

• 批准号: 10467982
• 负责人: Taixing Cui
• 金额: --
• 依托单位: VETERANS HEALTH ADMINISTRATION
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10467982
• 关键词: Admission activity; Animal Model; Automobile Driving; Autophagocytosis; Biological Markers; Blood Circulation; Cardiac; Cardiac Myocytes; Cardiomyopathies; Cessation of life; Clinical; Complex; Consumption; Deubiquitinating Enzyme; Diagnostic; FRAP1 gene; Failure; Functional disorder; Genes; Genetic; Geometry; Health system; Heart; Heart Diseases; Heart failure; Hsc70 protein; Human; Hydrolase; Knock-out; Link; Mediating; Mediator of activation protein; Medical; Medical Research; Membrane Proteins; Mission; Molecular; Mus; Outcome; Pathogenicity; Pathologic; Pathology; Pathway interactions; Patients; Pharmacology; Phenotype; Phosphorylation; Phosphotransferases; Physiological; Pilot Projects; Proteasome Inhibition; Protein Dephosphorylation; Proteins; Regulation; Research; Resources; Risk Factors; Role; Signal Transduction; Sirolimus; Site; Symptoms; Testing; Therapeutic; Time; Transgenic Organisms; Ubiquitin; Up-Regulation; Veterans; Wild Type Mouse; base; improved; in vivo; inhibition of autophagy; inhibitor/antagonist; mouse model; myocardial damage; novel; novel diagnostics; novel marker; novel strategies; novel therapeutics; overexpression; patient population; pressure; prognostic value; programs; translational study

Heart failure (HF) is the number one reason for admission among patients in the Veteran (VA) health system, consuming a significant portion of VA medical resources. However, the molecular mechanism of HF is poorly understood and the treatment of HF still remains at the level of controlling symptom and reducing risk factors without a cure. Hence, further research into developing pathogenic mechanism-specific novel therapies for HF is an urgent need. Our pilot studies have demonstrated that a deubiquitinating enzyme, ubiquitin carboxyl- terminal hydrolase L1 (UCH-L1) is upregulated in the cardiomyocytes of mouse and human failing hearts. In addition, cardiomyocyte-restricted (CR) transgenic overexpression of UCH-L1 (CR-UCH-L1 Tg) exaggerates cardiac pathological remodeling and dysfunction in a mouse model of pressure overload (PO)-induced cardiomyopathy and HF, and the CR-UCH-L1 Tg-induced adverse phenotypes could be rescued by the treatment with a reversible, competitive, act-site directed inhibitor of UCH-L1, LDN-57444. Moreover, UCH-L1 is capable of suppressing autophagy in PO-hearts, which serves as crucial adaptive mechanism to protect against PO-induced cardiomyopathy and HF. At the molecular level, it is most likely that UCH-L1 facilitates mTORC1 (mechanistic target of rapamycin complex 1) dependent inactivation of ULK1 (uncoordinated-51-like kinase 1)-mediated autophagy induction and the activation of DAP1 (death-associated protein 1)-mediated inhibition of autophagy flux in cardiomyocytes. Interestingly, the circulating level of exosomal UCH-L1 is elevated conceivably via a mechanism of autophagy inhibition (AI)-induced increases in exosomal loading and secretion of UCH-L1 in cardiomyocytes of PO-hearts. Collectively, our findings compellingly support the hypothesis that targeting UCH-L1 is a novel approach for the treatment of HF and circulating exosomal UCH- L1 serves as novel biomarker of HF. This hypothesis will be tested by three specific aims in mouse models as well as in VA HF patients as follows: Aim 1 is to determine the therapeutic potential of targeting UCH-L1 in HF in mice. The impact of CR-UCH-L1 knockout (KO) and the efficacy of UCH-L1 inhibitor, LDN-57444 on PO- induced cardiomyopathy and HF will be investigated. Aim 2 is to determine the molecular mechanism by which UCH-L1 mediates HF, testing the hypothesis that UCH-L1 controls the assembly of mTORC1 in favor of increasing the access of mTOR to ULK1 for phosphorylation of ULK1 at S757 while decreasing the association of mTOR with DAP1 for dephosphorylation of DAP1 to enhance AI in cardiomyocytes, thereby exaggerating cardiac pathological remodeling and dysfunction. We will determine whether CR-UCH-L1 Tg-induced adverse phenotypes are rescued by additional enhancement of cardiac autophagy via CR overexpression of autophagy related gene (Atg)7 or autophagy activator, rapamycin. Also, we will dissect the signaling mechanism by which UCH-L1 inhibits autophagy with an initial focus on the regulation of mTORC1 assembly thereby inhibiting ULK1-mediated autophagy induction while enhancing DAP1-mediated suppression of autophagy flux in cardiomyocytes. Aim 3 is to define PO-induced upregulation and release of cardiac UCH-L1 with a focus on the molecular mechanism for exosomal release of UCH-L1 into circulation in animal models and the diagnostic and/or prognostic value of circulating exosomal UCH-L1 in VA HF patients. While a critical role of AI in driving cognate of heat shock protein 70 (HSC70)-mediated exosomal loading of UCH-L1 and secretory carrier membrane protein 5 (SCAMP5)-mediated exosomal release of UCH-L1 in cardiomyocytes with accumulated UCH-L1 will be dissected, the concept that circulating exosomal UCH-L1 is a novel biomarker for evaluating HF in VA patients will be tested. The outcome will pave the way for translational studies of targeting UCH-L1 to treat and manage cardiac disease and HF. Thus, this proposal outcome will, in addition to establishing a unique and independent research program relevant to the VA medical research mission, result in a mechanistically based therapeutic approach for reducing the HF burden within the VA patient population.

心力衰竭 (HF) 是退伍军人 (VA) 医疗系统中患者入院的首要原因， 消耗了 VA 很大一部分医疗资源。然而，HF的分子机制尚不明确。 心力衰竭的治疗仍停留在控制症状和减少危险因素的水平 无药可救。因此，进一步研究开发针对心力衰竭致病机制的新型疗法 是一个迫切的需要。我们的初步研究表明，去泛素化酶，泛素羧基- 末端水解酶 L1 (UCH-L1) 在小鼠和人类衰竭心脏的心肌细胞中表达上调。在 此外，UCH-L1 (CR-UCH-L1 Tg) 的心肌细胞限制性 (CR) 转基因过度表达夸大了 压力超负荷（PO）诱导的小鼠模型的心脏病理重塑和功能障碍 心肌病和心力衰竭，以及 CR-UCH-L1 Tg 诱导的不良表型可以通过 使用可逆、竞争性、作用位点定向的 UCH-L1 抑制剂 LDN-57444 进行治疗。此外，UCH-L1 能够抑制 PO 心脏中的自噬，这是保护心脏的重要适应性机制 对抗PO诱发的心肌病和心力衰竭。在分子水平上，UCH-L1很可能促进 mTORC1（雷帕霉素复合物 1 的机械靶点）依赖性 ULK1 失活（不协调 51 样） 激酶 1) 介导的自噬诱导和 DAP1（死亡相关蛋白 1）介导的激活 抑制心肌细胞的自噬通量。有趣的是，外泌体 UCH-L1 的循环水平是 可以想象，通过自噬抑制（AI）诱导的外泌体负载增加和 PO-heart 心肌细胞中 UCH-L1 的分泌。总的来说，我们的研究结果有力地支持了 假设靶向 UCH-L1 是治疗心力衰竭和循环外泌体 UCH-的新方法 L1 是 HF 的新型生物标志物。这一假设将通过小鼠模型中的三个特定目标进行检验： 以及 VA HF 患者如下：目标 1 是确定靶向 UCH-L1 在 HF 中的治疗潜力 在小鼠中。 CR-UCH-L1 敲除 (KO) 的影响和 UCH-L1 抑制剂 LDN-57444 对 PO-的功效 将调查诱发的心肌病和心力衰竭。目标 2 是确定其分子机制 UCH-L1 介导 HF，检验 UCH-L1 控制 mTORC1 组装的假设，有利于 增加 mTOR 与 ULK1 的接触，使 ULK1 在 S757 处磷酸化，同时减少关联 mTOR 与 DAP1 的结合使 DAP1 去磷酸化，从而增强心肌细胞中的 AI，从而夸大 心脏病理重塑和功能障碍。我们将确定 CR-UCH-L1 Tg 是否会诱导不良反应 通过自噬的 CR 过度表达来额外增强心脏自噬，从而挽救表型 相关基因（Atg）7或自噬激活剂雷帕霉素。此外，我们还将剖析信号机制 UCH-L1 抑制自噬，最初重点是调节 mTORC1 组装，从而抑制 ULK1 介导的自噬诱导，同时增强 DAP1 介导的自噬流抑制 心肌细胞。目标 3 是定义 PO 诱导的心脏 UCH-L1 上调和释放，重点是 UCH-L1 外泌体释放到动物模型循环中的分子机制及其诊断 和/或 VA HF 患者循环外泌体 UCH-L1 的预后价值。虽然人工智能在驾驶中发挥着关键作用 热休克蛋白 70 (HSC70) 介导的 UCH-L1 和分泌载体的外泌体负载的同源物 膜蛋白 5 (SCAMP5) 介导的心肌细胞中 UCH-L1 的外泌体释放 UCH-L1将被剖析，循环外泌体UCH-L1是一种用于评估的新型生物标志物的概念 将测试 VA 患者的心力衰竭。该结果将为针对 UCH-L1 的转化研究铺平道路 治疗和管理心脏病和心力衰竭。因此，除了建立一个 与 VA 医学研究任务相关的独特且独立的研究计划，产生了 基于机械原理的治疗方法，用于减轻 VA 患者群体的心力衰竭负担。