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）在相对小比例的遗传异常患者中发生，例如，骨形态发生蛋白受体（BMPR）2的突变，或与环境暴露相结合，例如，艾滋病毒或安非他明（AMPH）滥用，异常基因和环境因素可能是叠加或协同引起疾病。我们对培养细胞和BMPR 2功能障碍的转基因小鼠的初步研究表明，当异常基因与不利的环境因素相互作用时，共同的过程被放大。例如，我们确定BMPR 2的缺失导致肺动脉（PA）平滑肌细胞（SMC）和成纤维细胞（Fibro）的弹性蛋白纤维的异常组装，并且我们假设这些纤维的加速降解将响应于由病毒感染引起的炎症而发生。类似地，BMPR 2的缺失降低PA内皮细胞（EC）中的细胞存活信号，并且 缺氧和AMPH进一步降低了上述信号，导致DNA损伤放大和PA EC凋亡。因此，本提案的目标是研究BMPR 2信号传导的丧失如何导致弹性蛋白纤维的组装受损，并且还使EC对细胞凋亡和DNA损伤敏感，以及是否与感染或AMPH组合，这些异常的后果和放大增加了PH的严重程度或损害了PH的解决。在初步研究中，我们表明PA SMC和Fibro中BMPR 2的缺失损害了弹性蛋白纤维通过减少重组蛋白和激活转化生长抑制因子的组装 因子（TGIF），以防止弹性蛋白原的合成。在具体目标1中，我们将确定BMPR 2的缺失是否会减少原纤维蛋白稳定蛋白，如syndecans和ADAMTS去整合素。我们将确定在BMPR 2减少的情况下观察到的p-p38水平升高是否激活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，以及这是否受到BMPR 2损失的影响。在Bmpr 2 +/-Alk 3 +/-小鼠中，或在SMC或Fibro中缺失Bmpr 2的小鼠中，我们将阐明由血管周围炎性细胞响应于亲血管病毒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，包括新生内膜形成和严重PH。缺氧和AMPH。因此，在具体目标2中，我们将研究这是否与通过减少BMPR 2、缺氧和AMPH激活的类似磷酸酶有关，以及pAkt功能的进行性扰动是否通过损害p53依赖性基因调控引起DNA损伤和EC凋亡。我们将确定在Bmpr 2 +/-Alk 3 +/-和EC中Bmpr 2缺失的小鼠中，AMPH介导的DNA损伤放大是否会加剧缺氧PH和血管变化并阻止逆转。了解BMPR 2功能障碍对环境损害的贡献将有助于预防和最大限度地减少高危患者的PH。