Novel mechanism for eNAMPT secretion in PAH vascular remodeling

PAH 血管重塑中 eNAMPT 分泌的新机制

• 批准号: 10677318
• 负责人: Marisela Rodriguez
• 金额: $ 4.01万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-24 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10677318
• 关键词: ATP-Binding Cassette Transporters; Acute Respiratory Distress Syndrome; Address; Antioxidants; Apoptosis; Binding; Blood Vessels; Cell Proliferation; Cell Separation; Cell Survival; Cell membrane; Cells; Cessation of life; Dimerization; Disease; Endothelial Cells; Endothelin-1; Endothelium; Enzymes; Epithelium; Functional disorder; Generations; Genetic Transcription; Genomics; Human; Hypertrophy; Hypoxia; Inflammasome; Inflammatory; Inflammatory Response; Laboratories; Leukocytes; Ligation; Luciferases; Lung; Lymphocyte; Medial; Mesenchymal; Molecular; Natural Immunity; Nicotinamide adenine dinucleotide; Pathway interactions; Patients; Pattern; Plasma; Platelet-Derived Growth Factor; Predisposition; Process; Procollagen-Proline Dioxygenase; Progressive Disease; Proliferating; Proteins; Pulmonary Circulation; Pulmonary Fibrosis; Pulmonary Vascular Resistance; Pulmonary artery structure; Reporter; Resistance; Response Elements; Right Ventricular Dysfunction; Right Ventricular Function; Rodent; Role; Severities; Signal Transduction; Smooth Muscle Myocytes; Stimulus; TLR4 gene; Tertiary Protein Structure; Therapeutic; Tissues; Training; Transcriptional Regulation; Translations; Vascular Endothelial Growth Factors; Vascular remodeling; curative treatments; cytokine; extracellular; extracellular vesicles; improved; inhibitor; insight; mutant; neutralizing monoclonal antibodies; nicotinamide phosphoribosyltransferase; novel; pharmacologic; pre-clinical; promoter; pulmonary arterial hypertension; pulmonary arterial pressure; pulmonary vascular remodeling; response; right ventricular failure; therapeutic target; transcription factor

ABSTRACT Pulmonary arterial hypertension (PH) is a progressive disease leading to pulmonary vascular remodeling, increased pulmonary arterial pressures, declining right ventricular (RV) function, right heart failure, and death. No curative therapies are currently available. In this F31 application, the PI will train in the acclaimed translational laboratory of Joe GN Garcia, MD and seek to address the unmet need for novel effective PAH therapeutic strategies by focusing on eNAMPT (extracellular nicotinamide phosphoribosyltransferase). eNAMPT is a novel damage-associated molecular pattern protein (DAMP) and PAH target identified by the Garcia lab utilizing genomic–intensive approaches. Intracellular NAMPT mainly serves as a rate-limiting enzyme in nicotinamide adenine dinucleotide (NAD) synthesis. However, secreted extracellular eNAMPT (from leukocytes, lymphocytes, endothelium, epithelium) ligates the Toll-like receptor 4 (TLR4) to potently activate this inflammatory signaling cascade. eNAMPT/TLR4 participation in innate immunity inflammatory responses is key to the severity of several serious inflammatory disorders (ARDS, lung fibrosis) including PH with elevated plasma eNAMPT levels in PH subjects correlating with RV dysfunction. Increased eNAMPT secretion is influenced by NAMPT promoter SNPs and NAMPT transcriptional regulation by anti-oxidant response elements and hypoxia response elements induced by transcription factors such as HIF-2α. We have demonstrated that the eNAMPT/TLR4 pathway is highly druggable as a humanized eNAMPT-neutralizing mAb effectively reduced the severity of preclinical PH. Several key gaps remain, however, in fundamentally understanding the role of eNAMPT in PH pathobiology. For example, it remains unclear as to whether endothelial cells (ECs) or smooth muscle cells (SMCs) are the primary target cell for eNAMPT involvement in PH. In Specific Aim #1 (SA), the PI will examine EC- and SMC-specific NAMPT promoter responses to PAH stimuli that increase NAMPT transcriptional activities and translation. SA #2 will investigate the EC- and SMC-specific intracellular mechanisms contributing to eNAMPT secretion into the circulation by PAH stimuli focusing on the role of NAMPT dimerization, inflammasome and ABC transporter activation and generation of extracellular vesicles. Finally, utilizing human and rodent tissues, SA #3 will define EC- and SMC-specific eNAMPT-induced responses by examining cytosolic Ca2+ signaling, cell proliferation/activation, cell survival, EMT activity and angiogenic activity as readouts. Together, these studies will provide key novel mechanistic insights into eNAMPT’s influence on vascular remodeling and PH pathobiology.

摘要 肺动脉高压（PH）是一种导致肺血管重构的进行性疾病， 肺动脉压升高、右心室（RV）功能下降、右心衰竭和死亡。 目前没有治愈性疗法。在这个F31应用程序中，PI将在广受好评的翻译中进行训练。 Joe GN Garcia，MD的实验室，寻求解决新型有效PAH治疗药物的未满足需求 通过专注于eNAMPT（细胞外烟酰胺磷酸核糖基转移酶）的策略。eNAMPT是一部小说 损伤相关分子模式蛋白（DAMP）和PAH靶标由Garcia实验室利用 基因组密集型方法。细胞内NAMPT主要作为烟酰胺代谢的限速酶 腺嘌呤二核苷酸（NAD）合成。然而，分泌的细胞外eNAMPT（来自白细胞，淋巴细胞， 内皮细胞，上皮细胞）连接Toll样受体4（TLR 4）以有效激活这种炎症信号传导 级联。eNAMPT/TLR 4参与先天免疫炎症反应是几种炎症反应严重程度的关键。 严重炎症性疾病（ARDS、肺纤维化），包括PH伴PH患者血浆eNAMPT水平升高 与RV功能障碍相关的受试者。eNAMPT分泌增加受NAMPT启动子SNP的影响 抗氧化反应元件和缺氧反应元件对NAMPT转录的调控 由转录因子如HIF-2α诱导。我们已经证明，eNAMPT/TLR 4途径是 作为人源化eNAMPT-中和mAb，其具有高度可药用性，有效降低了临床前PH的严重程度。 然而，在从根本上理解eNAMPT在PH病理生物学中的作用方面仍然存在一些关键差距。为 例如，目前尚不清楚内皮细胞（EC）或平滑肌细胞（SMC）是否是主要的血管内皮细胞。 在特定目标#1（SA）中，PI将检查EC和SMC特异性 NAMPT启动子对PAH刺激物的反应增加NAMPT转录活性和翻译。SA #2将研究EC和SMC特异性细胞内机制，有助于eNAMPT分泌到 PAH刺激的循环，重点关注NAMPT二聚化、炎性小体和ABC转运蛋白的作用 细胞外囊泡的激活和产生。最后，利用人类和啮齿动物组织，SA #3将定义 EC和SMC特异性eNAMPT诱导的反应，通过检查胞质Ca 2+信号，细胞 增殖/活化、细胞存活、EMT活性和血管生成活性作为读数。这些研究一起 将为eNAMPT对血管重塑和PH的影响提供关键的新机制见解 病理生物学