Pulmonary Hypertension in Genetically Modified Mice

转基因小鼠的肺动脉高压

• 批准号: 9459614
• 负责人: Marlene Rabinovitch
• 金额: $ 1.73万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-10 至 2018-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9459614
• 关键词: ADAMTS; Address; Affect; Amphetamine Abuse; Amphetamines; Animals; Apoptosis; Autoimmunity; BMPR2 gene; Blood Vessels; Cell Hypoxia; Cell Survival; Cells; Cessation of life; Clinical; Conditioned Culture Media; Coupled; Cultured Cells; DNA Damage; DNA amplification; Disease; Disintegrins; EGF gene; Elastases; Elastic Fiber; Elastin; Elastin Fiber; Endothelial Cells; Environmental Exposure; Environmental Risk Factor; Exposure to; FBN1; Family; Fiber; Fibroblasts; Functional disorder; Funding; Gene Expression Regulation; Genes; Goals; Grant; HIV; Heterozygote; Human; Hypoxia; Immune; Impairment; Infection; Inflammation; Inflammatory; Lesion; Lung; MAPK14 gene; Mediating; Molecular; Molecular Abnormality; Mus; Mutation; Pathogenesis; Pathway interactions; Patients; Penetrance; Peripheral; Pharmaceutical Preparations; Phosphoric Monoester Hydrolases; Phosphorylation; Predisposition; Process; Production; Proteins; Pulmonary Hypertension; Recovery; Reporting; Resolution; Risk; Scaffolding Protein; Scleroderma; Severities; Signal Transduction; Smooth Muscle Myocytes; System; TP53 gene; Toxin; Transforming Growth Factor beta; Transgenic Mice; Translating; Tropoelastin; United States National Institutes of Health; Virus; Virus Diseases; amphetamine use; arterial remodeling; bone morphogenetic protein receptors; fibrillin; gene environment interaction; metallothionein III; prevent; public health relevance; pulmonary arterial hypertension; receptor; response; syndecan

 DESCRIPTION (provided by applicant): Since pulmonary hypertension (PH) develops in a relatively small proportion of patients with a genetic abnormality, e.g., a mutation in bone morphogenetic protein receptor (BMPR)2, or in conjunction with an environmental exposure, e.g., HIV or amphetamine (AMPH) abuse, aberrant genes and environmental factors are likely additive or synergistic in causing disease. Our preliminary studies with cultured cells and transgenic mice with dysfunctional BMPR2 suggest that common processes are amplified when the aberrant gene interacts with an adverse environmental factor. For example, we determined that loss of BMPR2 causes abnormal assembly of elastin fibers by pulmonary arterial (PA) smooth muscle cells (SMC) and fibroblasts (Fibro), and we hypothesize that accelerated degradation of these fibers would occur in response to the inflammation resulting from a viral infection. Similarly, loss of BMPR2 reduces cell survival signals in PA endothelial cells (EC), and hypoxia and AMPH further decrease the same signal, resulting in amplification of DNA damage and PA EC apoptosis. The goal of the present proposal is therefore to investigate how loss of BMPR2 signaling causes impaired assembly of elastin fibers and also renders EC susceptible to apoptosis and DNA damage, and whether, in combination with infection or AMPH, the consequences and amplification of these abnormalities increases severity or impairs resolution of PH. In preliminary studies we showed that loss of BMPR2 in PA SMC and Fibro impairs elastin fiber assembly by reducing fibrillin proteins and activating transforming growth inhibitory factor (TGIF), to prevent synthesis of tropoelastin. In Specific Aim 1, we will determine whether loss of BMPR2 decreases fibrillin-stabilizing proteins such as syndecans and ADAMTS disintegrins. We will establish whether the elevated level of p-p38 observed with reduced BMPR2 activates TGIF, and whether EGF phosphorylation is a necessary intermediary. We will assess the contribution of PA EC to formation of elastin fibers by SMC, and whether this is compromised by loss of BMPR2. In Bmpr2+/-Alk3+/- mice, or in mice with deleted Bmpr2 in SMC or Fibro, we will elucidate whether elastase activity, produced by perivascular inflammatory cells in response to a vasculotropic virus, will cause the abnormal PA elastin fibers to degrade, promoting adverse remodeling, including neointimal formation, and severe PH. In preliminary studies we showed a progressive loss of pAkt with reduced BMPR2, hypoxia and AMPH. Thus, in Specific Aim 2 we will investigate whether this is related to a similar phosphatase activated by reduced BMPR2, hypoxia and AMPH, and whether progressive perturbation in pAkt function causes DNA damage and EC apoptosis by impairing p53 dependent gene regulation. We will determine, in Bmpr2+/-Alk3+/- and in mice with loss of Bmpr2 in EC, whether AMPH mediated amplification of DNA damage worsens hypoxic PH and vascular changes and prevents reversal. Understanding the contribution of BMPR2 dysfunction to environmental insults will facilitate approaches to prevent and minimize PH in patients at risk.

 描述（由申请人提供）：由于肺动脉高压（PH）在具有遗传异常（例如骨形态发生蛋白受体（BMPR）2突变）的患者中发生的比例相对较小，或者与环境暴露（例如HIV或安非他明（AMPH）滥用）相结合，因此异常基因和环境因素可能会叠加或协同导致疾病。我们对培养细胞和 BMPR2 功能失调的转基因小鼠的初步研究表明，当异常基因与不利环境因素相互作用时，常见过程会被放大。例如，我们确定BMPR2的缺失会导致肺动脉（PA）平滑肌细胞（SMC）和成纤维细胞（Fibro）异常组装弹性蛋白纤维，并且我们假设这些纤维会加速降解，以应对病毒感染引起的炎症。同样，BMPR2 的缺失会降低 PA 内皮细胞 (EC) 中的细胞存活信号，并且 缺氧和 AMPH 进一步降低相同的信号，导致 DNA 损伤放大和 PA EC 凋亡。因此，本提案的目标是研究 BMPR2 信号传导的缺失如何导致弹性蛋白纤维的组装受损，并使 EC 容易发生细胞凋亡和 DNA 损伤，以及与感染或 AMPH 相结合，这些异常的后果和放大是否会增加 PH 的严重性或损害其解决。在初步研究中，我们表明 PA SMC 和 Fibro 中 BMPR2 的缺失会通过减少原纤维蛋白并激活转化生长抑制来损害弹性蛋白纤维组装 因子（TGIF），阻止原弹性蛋白的合成。在具体目标 1 中，我们将确定 BMPR2 的缺失是否会降低纤维蛋白稳定蛋白（例如多配体聚糖和 ADAMTS 解整合素）。我们将确定 BMPR2 减少时观察到的 p-p38 水平升高是否会激活 TGIF，以及 EGF 磷酸化是否是必要的中介。我们将评估 PA EC 对 SMC 形成弹性蛋白纤维的贡献，以及这是否会因 BMPR2 的缺失而受到影响。在 Bmpr2+/-Alk3+/- 小鼠中，或在 SMC 或 Fibro 中缺失 Bmpr2 的小鼠中，我们将阐明血管周围炎症细胞响应亲血管病毒而产生的弹性蛋白酶活性是否会导致异常 PA 弹性蛋白纤维降解，促进不良重塑，包括新内膜形成和严重 PH。在初步研究中，我们发现随着 BMPR2、缺氧和 AMPH 的减少，pAkt 逐渐丧失。因此，在特定目标 2 中，我们将研究这是否与 BMPR2 减少、缺氧和 AMPH 激活的类似磷酸酶有关，以及 pAkt 功能的渐进扰动是否通过损害 p53 依赖性基因调控而导致 DNA 损伤和 EC 凋亡。我们将确定，在 Bmpr2+/-Alk3+/- 和 EC 中 Bmpr2 缺失的小鼠中，AMPH 介导的 DNA 损伤放大是否会恶化缺氧 PH 和血管变化并阻止逆转。了解 BMPR2 功能障碍对环境损害的影响将有助于采取措施预防和尽量减少高危患者的 PH。