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 该应用程序旨在满足对肺动脉高压治疗疗法的未满足需求 （PAH），一种致命的疾病，预后很沮丧。 PAH病理生物学的一个关键特征是深刻的Pulmo- 缺乏新的治疗策略的液体血管重塑。我们成功地进行了 基因组密集型方法鉴定烟酰胺磷脂基转移酶（NAMPT）为一种新型PAH 来自PAH患者的PBMC中可进行了不断更新的目标。我们也证明了明显增加 来自人类PAH受试者和临床前PAH模型的重塑血管中的NAMPT表达（小鼠和 大鼠）nampt位于肺内皮细胞（EC）。我们进一步报道了降低的可用性 分泌或细胞外NAMPT或ENAMPT（通过中和抗体，siRNAS，NAMPT +/-小鼠）DRA-- 在我们的临床前PAH模型中，Matly Pah的严重程度减弱了。检验nampt促进的假设 pH发育过程中的血管重塑并充当新型PAH治疗靶点，特定目标＃1（SA ＃1）将进一步表征响应PAH刺激的NAMPT表达（PDGF，VEGF， PHD2抑制剂，内皮素-1）专注于启动子活性和表观遗传调节（DNA甲基化，miR-- NAS）和特定转录因子（HIF-2A，STAT5，SOX17） 脚本。 SA＃2将机械检查细胞外NAMPT（ENAMPT）对血管的贡献 通过影响EC凋亡和平滑肌细胞（SMC）激活的重塑（CA2+信号传导和增殖） ERATION）。我们将特别关注ENAMPT与Toll -like受体4（TLR4）的相互作用，我们最近 被识别为NAMPT受体并探索ENAMPT-TLR4介导的NFκB转录活性为一种新型 ENAMPT可能会影响血管重塑的机制。 SA＃3将利用我们先前已发表的研究 - IES和初步数据表明，NAMPT 5'启动子多态性（SNP）改变NAMPT启动子 急性呼吸窘迫中易感性和严重程度的风险也大大增加了活动 综合征（ARDS），将在PAH中进行评估。 SA＃3研究将确定NAMPT SNP对 转录调节，对ENAMPT-TLR4结合和PAH中的NFκB激活。最后，SA＃4将定义 已建立的PAH，降低NAMPT表达（条件EC基因敲除小鼠）的治疗效率， 消除AMPT（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）。在杰出调查员的亲密参与的支持下 大量的高度翻译出版/初步数据将NAMPT作为一种新颖的先天免疫力 调节器，此应用程序将成功定义NAMPT参与PAH易感性，病理生物学和 严重程度。