Novel Involvement of NAMPT and TLR4 in PAH Vascular Remodeling

NAMPT 和 TLR4 在 PAH 血管重塑中的新参与

• 批准号: 10093119
• 负责人: Joe G. N. Garcia
• 金额: $ 46.05万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2023-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10093119
• 关键词: Address; Adult Respiratory Distress Syndrome; Apoptosis; Attenuated; Binding; Blood; Blood Vessels; Candidate Disease Gene; Cell Proliferation; Cell Survival; Cells; Cessation of life; DNA Methylation; Data; Development; Disease; Endothelial Cells; Endothelin-1; Enzymes; Failure; Family; Functional disorder; Genes; Genetic; Genetic Polymorphism; Genetic Transcription; Genomics; Human; Inflammation; Inflammatory; Knockout Mice; Lead; Ligands; Lung; Lung Inflammation; Lung diseases; Mediating; MicroRNAs; Modeling; Mouse Protein; Mus; Natural Immunity; Pathogenicity; Patients; Peptides; Peripheral Blood Mononuclear Cell; Platelet-Derived Growth Factor; Play; Predisposition; Process; Prognosis; Progressive Disease; Publishing; Pulmonary Vascular Resistance; Pulmonary vessels; Rattus; Regulation; Regulatory Element; Reporting; Research Personnel; Resistance; Risk; Role; SOX17 gene; Severities; Signal Transduction; Small Interfering RNA; Smooth Muscle Myocytes; Stat5 protein; Stimulus; Structure; TLR4 gene; Testing; Therapeutic; Transcriptional Regulation; Treatment Efficacy; Vascular Endothelial Growth Factors; Vascular remodeling; Ventricular; Wild Type Mouse; analog; attenuation; base; curative treatments; cytokine; demethylation; epigenetic regulation; extracellular; genome wide association study; improved; inhibitor/antagonist; mouse toll-like receptor 4; neutralizing antibody; new therapeutic target; nicotinamide phosphoribosyltransferase; novel; novel therapeutic intervention; pre-clinical; promoter; pulmonary arterial hypertension; receptor; response; targeted treatment; therapeutic target; transcription factor; translational study

ABSTRACT This application seeks to address the unmet need for curative therapies in pulmonary arterial hypertension (PAH), a fatal disease with a dismal prognosis. A key feature of the pathobiology of PAH is the profound pulmo- nary vascular remodeling for which new therapeutic strategies are woefully lacking. We successfully employed genomic–intensive approaches to identify nicotinamide phosphoribosyltransferase (NAMPT) as a novel PAH target that is robustly upregulated in PBMCs from PAH patients. We also demonstrated markedly increased NAMPT expression in remodeled vessels from human PAH subjects and in preclinical PAH models (mice and rats) with NAMPT localized to lung endothelial cells (ECs). We further reported that reducing the availability of secreted or extracellular NAMPT or eNAMPT (via eNAMPT neutralizing antibodies, siRNAs, Nampt+/- mice) dra- matically attenuated PAH severity in our preclinical PAH models. To test the hypothesis that NAMPT promotes vascular remodeling during PH development and serves as a novel PAH therapeutic target, Specific Aim #1 (SA #1) will further characterize the regulation of NAMPT expression in response to PAH stimuli (PDGF, VEGF, PHD2 inhibitor, endothelin-1) focusing on promoter activity and epigenetic regulation (DNA methylation, miR- NAs) and specific transcription factors (HIF-2a, STAT5, SOX17) that we have shown to regulate NAMPT tran- scription. SA #2 will mechanistically examine the contribution of extracellular NAMPT (eNAMPT) to vascular remodeling via influences on EC apoptosis and smooth muscle cell (SMC) activation (Ca2+ signaling and prolif- eration). We will specifically focus on the interaction of eNAMPT with Toll–like receptor 4 (TLR4), that we recently identified as the NAMPT receptor and explore eNAMPT-TLR4 mediated NFκB transcriptional activities as a novel mechanism by which eNAMPT may influence vascular remodeling. SA #3 will leverage our prior published stud- ies and preliminary data demonstrating that NAMPT 5’ promoter polymorphisms (SNPs) alter NAMPT promoter activity which also confer significantly increased risk for susceptibility and severity in acute respiratory distress syndrome (ARDS) and will be assessed in PAH. SA #3 studies will determine the influence of NAMPT SNPs on transcriptional regulation, on eNAMPT-TLR4 binding, and NFκB activation in PAH. Finally, SA #4 will define in established PAH, the therapeutic efficacy of reduced NAMPT expression (conditional EC knockout mice), eN- AMPT elimination (neutralizing antibodies), inhibition of NAMPT enzymatic activity (novel FK-866 analogues), and TLR4 antagonism (novel peptide inhibitors). Supported by intimate involvement of outstanding investigators and substantial highly translational published/preliminary data highlighting NAMPT as a novel innate immunity modulator, this application will successfully define NAMPT participation in PAH susceptibility, pathobiology, and severity.

抽象的 该申请旨在解决肺动脉高压治疗未得到满足的需求 (PAH)，一种预后不良的致命疾病，PAH 病理学的一个关键特征是严重的肺损伤。 不幸的是，我们成功地采用了新的治疗策略。 基因组强化方法鉴定烟酰胺磷酸核糖基转移酶 (NAMPT) 是一种新型 PAH 我们还证明了 PAH 患者的 PBMC 中显着上调的目标。 NAMPT 在人类 PAH 受试者的重塑血管和临床前 PAH 模型（小鼠和 大鼠）的 NAMPT 定位于肺内皮细胞（EC），我们进一步报告说，减少了 NAMPT 的可用性。 分泌的或细胞外的 NAMPT 或 eNAMPT（通过 eNAMPT 中和抗体、siRNA、Nampt+/- 小鼠）dra- 在我们的临床前 PAH 模型中显着减弱 PAH 严重程度 检验 NAMPT 促进的假设。 PH 发展过程中的血管重塑，可作为新型 PAH 治疗靶点，具体目标 #1 (SA #1) 将进一步表征 NAMPT 表达对 PAH 刺激（PDGF、VEGF、 PHD2 抑制剂，内皮素-1）专注于启动子活性和表观遗传调控（DNA 甲基化、miR- 我们已经证明可以调节 NAMPT 转录的NAs）和特定转录因子（HIF-2a、STAT5、SOX17） SA #2 将机械地检查细胞外 NAMPT (eNAMPT) 对血管的贡献。 通过影响 EC 凋亡和平滑肌细胞 (SMC) 激活（Ca2+ 信号传导和增殖）进行重塑 我们将特别关注 eNAMPT 与 Toll 样受体 4 (TLR4) 的相互作用，这是我们最近发现的。 鉴定为 NAMPT 受体并探索 eNAMPT-TLR4 介导的 NFκB 转录活性作为一种新的 eNAMPT 可能影响血管重塑的机制 SA #3 将利用我们之前发表的研究。 事实和初步数据表明 NAMPT 5' 启动子多态性 (SNP) 改变 NAMPT 启动子 活动也会显着增加急性呼吸窘迫的易感性和严重程度的风险 综合征 (ARDS) 并将在 PAH #3 研究中进行评估，以确定 NAMPT SNP 对的影响。 最后，SA #4 将在 PAH 中定义 eNAMPT-TLR4 结合和 NFκB 激活的转录调控。 建立PAH，减少NAMPT表达的治疗效果（条件EC敲除小鼠），eN- AMPT 消除（中和抗体）、抑制 NAMPT 酶活性（新型 FK-866 类似物）、 和 TLR4 拮抗作用（新型肽抑制剂）得到杰出研究人员的密切参与支持。 以及大量高度翻译性的已发表/初步数据，强调 NAMPT 作为一种新型先天免疫 调制器，该应用程序将成功定义 NAMPT 参与 PAH 易感性、病理学和 严重程度。