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）是在退伍军人（VA）卫生系统中入院的第一原因， 消耗大部分VA医疗资源。但是，HF的分子机制很差 理解和HF的治疗仍然处于控制症状和减少危险因素的水平 无法治愈。因此，进一步研究HF开发病理机理特异性新型疗法 是迫切需要的。我们的试点研究表明，泛素化酶，泛素羧基 - 末端水解酶L1（UCH-L1）在小鼠和人体失败心脏的心肌细胞中上调。在 补充，UCH-L1（Cr-uch-L1 Tg）的心肌细胞受限（CR）夸张 在压力超负荷的小鼠模型中，心脏病理重塑和功能障碍（PO）诱导的 心肌病和HF，以及CR-OUCH-L1 TG诱导的不良表型可以由 用UCH-L1的LDN-57444的可逆性，竞争性，ACT位点的抑制剂进行处理。而且，UCH-L1 能够抑制Po-Hearts中的自噬，这是保护的至关重要机制 反对PO引起的心肌病和HF。在分子水平上，UCH-L1很可能会促进 MTORC1（雷帕霉素复合物的机理目标1）依赖ULK1的失活（不协调的51 激酶1）介导的自噬诱导和DAP1的激活（死亡相关蛋白1）介导的 心肌细胞中自噬通量的抑制。有趣的是，外泌体UCH-L1的循环水平为 可以通过自噬抑制（AI）诱导的外泌体负荷增加和 PO-HERTS心肌细胞中UCH-L1的分泌。总的来说，我们的发现令人难以地支持 假设靶向UCH-L1是治疗HF和循环外泌体UCH-的一种新方法 L1是HF的新型生物标志物。该假设将通过鼠标模型中的三个特定目标来检验 以及在VA HF患者中如下：AIM 1是确定靶向HF中UCH-L1的治疗潜力 在老鼠中。 Cr-uch-L1敲除（KO）的影响和UCH-L1抑制剂的功效，LDN-57444对PO-的影响 将研究诱导的心肌病和HF。目标2是确定分子机制 UCH-L1介导HF，检验了UCH-L1控制MTORC1的假设，有利于 增加MTOR进入ULK1在S757时磷酸化的磷酸化，同时减少关联 用DAP1的MTOR用于DAP1的去磷酸化以增强心肌细胞的AI，从而夸大了 心脏病理重塑和功能障碍。我们将确定cr-uch-l1 tg诱导的不良 通过自噬过表达心脏自噬来挽救表型。 相关基因（ATG）7或自噬激活剂雷帕霉素。另外，我们将剖析信号传导机制 UCH-L1抑制自噬，最初侧重于MTORC1组件的调节，从而抑制 ULK1介导的自噬诱导，同时增强了DAP1介导的自噬通量的抑制 心肌细胞。 AIM 3是定义PO引起的上调和心脏UCH-L1的释放，重点是 在动物模型中，将UCH-L1外泌体释放到循环和诊断的分子机制 和/或VA HF患者循环外泌体UCH-L1的预后价值。而人工智能在驾驶中的关键作用 热休克蛋白70（HSC70）介导的UCH-L1和分泌载体的外泌体负荷 膜蛋白5（SCAMP5）介导的UCH-L1在累积的心肌细胞中的外泌体释放 将阐述UCH-L1，循环外泌体UCH-L1是评估的新型生物标志物的概念 VA患者的HF将进行测试。结果将为靶向UCH-L1的翻译研究铺平道路 治疗和管理心脏病和HF。因此，除了建立一个提案结果 与VA医学研究任务相关的独特独立研究计划，导致 基于机械的治疗方法来减轻VA患者人群中的HF负担。