Small molecule targeting of MLK3 for heart failure

MLK3 小分子靶向治疗心力衰竭

• 批准号: 9053110
• 负责人: Burns C Blaxall
• 金额: $ 39万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-12-14 至 2019-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9053110
• 关键词: Ablation; Address; Apoptosis; Arrhythmia; Attenuated; Biological Assay; Cardiac; Cardiac Myocytes; Cardiovascular Diseases; Cardiovascular Pathology; Cell Communication; Cells; Characteristics; Cicatrix; Communication; Complement; Data; Disease; Environment; Enzymes; Extracellular Matrix; FDA approved; Family; Fibroblasts; Fibrosis; Functional disorder; Genetic; HIV; Heart; Heart Hypertrophy; Heart failure; Human; Hypertrophy; In Vitro; Inflammation; Inflammation Mediators; Injury; Ischemia; Knock-in Mouse; Knockout Mice; Lead; MAP Kinase Kinase Kinase; MAPK14 gene; MAPK8 gene; Mechanics; Mediating; Mediator of activation protein; Modeling; Molecular; Mus; Muscle Cells; Myocardial; Myofibroblast; Nerve Degeneration; Neurons; Pathologic; Pathology; Phenotype; Phosphotransferases; Play; Reagent; Reperfusion Therapy; Rodent; Role; Series; Specificity; Stress; Supporting Cell; Surgical Models; Testing; Therapeutic; Tissues; Treatment Efficacy; United States; Validation; Ventricular; base; cell injury; cell type; clinically relevant; coronary fibrosis; extracellular; gain of function; in vivo; interstitial; mixed lineage kinase 3; mortality; mouse model; new therapeutic target; novel; novel strategies; outcome forecast; parity; periostin; predict clinical outcome; public health relevance; small molecule; sudden cardiac death; targeted treatment; therapeutic target

 DESCRIPTION (provided by applicant): Heart failure (HF), the final manifestation of most cardiovascular pathologies, is a devastating disease with poor prognosis. Pathologic cardiac remodeling (hypertrophy, fibrosis) is a known predictor of clinical outcome. We and others have demonstrated that pathologic activation of the cardiac fibroblast (CF) ("support cell") after cardiac injury releases various pro-hypertrophic/inflammatory mediators that target both cardiomyocytes (CM) ("functional cell") and fibroblasts to exacerbate remodeling. Elucidating mechanisms of this pathologic communication may hold therapeutic promise. Mixed Lineage Kinases (MLKs) are a family of stress-activated dual-specificity MAPKKKs upstream of JNK and p38 MAPKs. MLK3 in particular has been directly implicated in HIV-associated neurodegeneration (HAND), where it mediates microglial ("support cell") activation neuronal ("functional cell") damage. The similar pathogenic mechanisms of HAND and HF, namely deleterious "support cell-functional cell" communication, suggest a similar pathologic role for MLK3 in HF. However, the functional role(s) of MLKs in the heart remain largely unknown. We have generated global MLK3-/- and CF-targeted conditional MLK3fl/fl mice, in which we have found no basal cardiac phenotype; however, they are protected following myocardial injury. We have synthesized MLK3-specific inhibitory compounds, including URMC-099 (CNS-penetrant) and URMC-128 (CNS-impenetrant). URMC-099 reduced pathologic CF activation in vitro; it significantly attenuated cardiac hypertrophy and reduced interstitial fibrosis in pharmacologic and surgical models of HF, with no additive benefit in MLK3 global or conditional null mice. Our hypothesis is that MLK3 plays an important role in pathologic CF activation and HF progression and that its inhibition holds therapeutic promise for HF. To address our hypothesis, we propose the following Aims: Aim 1: Determine the therapeutic efficacy and specificity of MLK3 inhibition or ablation in clinically-relevant HF models in wild type, MLK3-/- and inducible CM or CF MLK3-/- mice. This aim will investigate the therapeutic efficacy and specificity of MLK3 pharmacologic inhibition (using our structurally distinct CNS-penetrant or -impenetrant compounds) and/or ablation (global, inducible CM, inducible resident or activated CF-restricted null mice) in ischemia-reperfusion (I/R) HF. Aim 2: Elucidate the cellular mechanisms underlying MLK3 inhibition and provide validation of MLK3 as a therapeutic target in both mouse and human HF. This aim will test the hypothesis that MLK3 inhibition or ablation will attenuate pathologic CF activation and subsequent CF/MF-CM pathologic crosstalk, using primary rodent CF and CM (Aim 1) subjected to pathogenic insults. Importantly, similar assays will ensue in human HF cardiac cells. MLK3 gain of function studies in vitro and in vivo will complement these studies. Our results may elucidate a new approach for treating HF and a novel paradigm of pathologic "support cell-functional cell" cross talk in the pathophysiology of multiple disease states.

 描述（由申请人提供）：心力衰竭（HF）是大多数心血管疾病的最终表现，是一种预后不良的破坏性疾病。病理性心脏重塑（肥厚、纤维化）是临床结果的已知预测因素。我们和其他人已经证明，心脏损伤后心脏成纤维细胞（CF）（“支持细胞”）的病理激活会释放各种促肥大/炎症介质，这些介质同时靶向心肌细胞（CM）（“功能细胞”）和成纤维细胞，从而加剧重塑。阐明这种病理通讯的机制可能具有治疗前景。混合谱系激酶 (MLK​​) 是 JNK 和 p38 MAPK 上游的应激激活双特异性 MAPKKK 家族。特别是 MLK3 直接涉及 HIV 相关神经变性 (HAND)，它介导小胶质细胞（“支持细胞”）激活神经元（“功能细胞”）损伤。 HAND 和 HF 的相似致病机制，即有害的“支持细胞-功能细胞”通讯，表明 MLK3 在 HF 中具有相似的病理作用。然而，MLK 在心脏中的功能作用仍然很大程度上未知。我们已经生成了全局 MLK3-/- 和 CF 靶向的条件 MLK3fl/fl 小鼠，其中我们没有发现基础心脏表型；然而，它们在心肌损伤后受到保护。我们合成了MLK3特异性抑制化合物，包括URMC-099（CNS渗透剂）和URMC-128（CNS渗透剂）。 URMC-099 减少体外病理性 CF 激活；在 HF 的药物和手术模型中，它显着减轻了心脏肥大并减少了间质纤维化，而在 MLK3 整体或条件无效小鼠中没有额外的益处。我们的假设是，MLK3 在病理性 CF 激活和心力衰竭进展中发挥重要作用，并且其抑制为心力衰竭的治疗带来希望。为了解决我们的假设，我们提出以下目标： 目标 1：确定 MLK3 抑制或消融在野生型、MLK3-/- 和诱导型 CM 或 CF MLK3-/- 小鼠临床相关 HF 模型中的治疗效果和特异性。该目标将研究 MLK3 药物抑制（使用我们结构不同的 CNS 渗透性或非渗透性化合物）和/或消融（整体、诱导型 CM、诱导型驻留或激活 CF 限制性无效小鼠）在缺血再灌注 (I/R) HF 中的治疗功效和特异性。目标 2：阐明 MLK3 抑制的细胞机制，并验证 MLK3 作为小鼠和人类心力衰竭的治疗靶点。该目标将使用遭受致病性损伤的原代啮齿类动物 CF 和 CM（目标 1）来测试 MLK3 抑制或消融将减弱病理性 CF 激活和随后的 CF/MF-CM 病理性串扰的假设。重要的是，类似的测定将在人类心力衰竭心肌细胞中进行。 MLK3 体外和体内功能获得研究将补充这些研究。我们的结果可能阐明治疗心力衰竭的新方法以及多种疾病状态病理生理学中病理性“支持细胞-功能细胞”串扰的新范例。