Novel therapeutic targets for bronchopulmonary dysplasia-associated pulmonary hypertension

项目摘要/摘要 肺动脉高压(PH)是一种复杂的多因素疾病，具有多种表现， 相关诊断和潜在原因。世界卫生组织将PH分为5个临床组，并将其作为 这些分类经常被修改，最近一次是在2013年，证明了这种疾病的复杂性。 作为一名新生儿专家，我对早产的并发症和最常见的 并发症是支气管肺发育不良(BPD)，这是一种影响前者的慢性肺部疾病 早产儿一直到成年。WHO的分类系统将BPD相关的PH归入第3类或PH 与呼吸道疾病有关。PH的发病机制可能涉及许多不同的细胞机制， 但大多数形式的PH，包括与BPD相关的PH，都涉及汇聚的生化途径。这条路 我对此很感兴趣，因为它在血管收缩和血管中都起着关键的作用 重塑(PH的标志)是L-精氨酸/NO通路。L-精氨酸可被一氧化氮代谢 合成酶(NOS)使强大的血管扩张剂NO，或通过精氨酸酶，多胺和脯氨酸的第一步 合成，对血管重塑过程中发生的细胞增殖至关重要。不对称 内源性一氧化氮合酶抑制物二甲基精氨酸(ADMA)可被NG，NG-二甲基精氨酸降解 二甲氨基水解酶(DDAH)，可促进内皮细胞内源性NO的产生。 L-精氨酸/NO通路的单核苷酸多态性(SNPs)与系统性红斑狼疮相关 然而，高血压和肺部疾病在肺高压中的作用，特别是与BPD相关的肺高压，尚未被 学习。我们的初步临床数据首次表明，有生物标志物参与了L- 精氨酸/NO途径可能在继续发展为BPD的早产儿中差异表达- 相关的PH与未发生PH的BPD患者进行比较。事实上，我们最近有3份出版物 显示差异表达；精氨酸酶1(ARG1)基因中的SNP、血浆ADMA水平和SNP 在DDAH1基因中。我们的目标是将这些新的、令人兴奋的和重要的初步临床发现 完成一系列研究，以便提供有针对性的研究培训，描述细胞机制 了解ARG1和DDAH1在体外的潜在作用，以及确定潜在的治疗方法 预防或治疗BPD相关性PH动物模型中BPD相关性PH的策略。我们会 通过围绕我们的翻译研究战略的结构化培训计划来实现这一目标 它有3个具体的目的：1)检验抑制ARG1功能将增加NO产生的假说 肺内皮细胞；2)验证抑制DDAH1功能会减少NO的假设 在肺内皮细胞中产生；3)检验有条件的小鼠ARG1基因敲除的假设 将减弱PH，而有条件地敲除DDAH1的小鼠将加剧PH，在 BPD相关PH。我们的目标是探索ARG1和/或DDAH1作为创新疗法的潜力 与BPD相关的PH的目标。

PROJECT SUMMARY/ABSTRACT Pulmonary hypertension (PH) is a complex multifactorial disease with a multitude of presentations, associated diagnoses, and underlying causes. The WHO has classified PH into 5 clinical groups, and as a testament to the complexity of the disease these classifications are frequently modified, most recently in 2013. As a neonatologist, I am very interested in the complications of preterm birth and the most common complication is bronchopulmonary dysplasia (BPD), which is a chronic lung disease that affects these former preterm infants well into adulthood. The WHO classification system puts BPD-associated PH in group 3 or PH associated with respiratory disease. The pathogenesis of PH can involve many different cellular mechanisms, but most forms of PH, including BPD-associated PH, involve converging biochemical pathways. The pathway that I have become interested in due to its pivotal involvement in both vasoconstriction and vascular remodeling (the hallmarks of PH) is the L-arginine/NO pathway. L-arginine can be metabolized by nitric oxide synthase (NOS) to make the potent vasodilator NO, or by arginase, the first step in polyamine and proline synthesis, vital for the cellular proliferation that occurs during vascular remodeling. Asymmetric dimethylarginine (ADMA), an endogenous NOS inhibitor, can be degraded by NG, NG-dimethylarginine dimethylaminohydrolase (DDAH), allowing for enhanced endogenous NO production in endothelial cells. Single nucleotide polymorphisms (SNPs) in the L-arginine/NO pathway have been associated with systemic hypertension and lung diseases, however their role in PH and specifically, BPD-associated PH, have not been studied. Our preliminary clinical data indicates, for the first time, that there are biomarkers involved in the L- arginine/NO pathway that may be differentially expressed in preterm infants that go on to develop BPD- associated PH compared to patients with BPD who do not develop PH. Indeed, we have 3 recent publications demonstrating differential expression; a SNP in the arginase 1 (ARG1) gene, plasma ADMA levels, and a SNP in the DDAH1 gene. Our goal is to take these novel, exciting, and important preliminary clinical findings and complete a series of studies in order to provide targeted research training, characterizing cellular mechanisms underlying the potential effects of ARG1 and DDAH1 in vitro, as well as identifying potential therapeutic strategies to either prevent or treat BPD-associated PH in an animal model of BPD-associated PH. We will achieve this goal through a structured training program that revolves around our translational research strategy which has 3 specific aims: 1) to test the hypothesis that inhibiting ARG1 function will increase NO production in pulmonary endothelial cells; 2) to test the hypothesis that inhibiting DDAH1 function will decrease NO production in pulmonary endothelial cells; 3) to test the hypothesis that a conditional mouse knock-out of ARG1 will attenuate PH, while a conditional mouse knock-out of DDAH1, will exacerbate PH, in a mouse model of BPD-associated PH. Our goal is to explore the potential for ARG1 and/or DDAH1 as innovative therapeutic targets for BPD-associated PH.