Mutation Specific Therapies in Patients with HPAH

HPAH 患者的突变特异性治疗

• 批准号: 8356472
• 负责人: Mark P. de Caestecker
• 金额: $ 7.8万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8356472
• 关键词: BMPR2 gene; Biological Models; Biotinylation; Blood Vessels; Cell membrane; Cell surface; Cells; Chemicals; Classification; Communities; Complement; Complementary DNA; Controlled Study; Cystic Fibrosis; Defect; Development; Disease; Endothelial Cells; Evaluation; Flow Cytometry; Foundations; Fractionation; Freezing; Functional disorder; Genotype; Inherited; Letters; Longevity; Lung; Mediating; Messenger RNA; Molecular Chaperones; Morphology; Mutation; Nature; Pathway interactions; Patients; Phosphorylation; Positioning Attribute; Process; Puromycin; RNA Decay; Receptor Gene; Sampling; Signal Transduction; Stem cells; Testing; Therapeutic; Tube; Vascular Diseases; abstracting; austin; base; cell type; cohort; functional group; human disease; inhibitor/antagonist; insight; mortality; mouse model; mutant; novel therapeutic intervention; novel therapeutics; peripheral blood; preclinical study; prevent; protein folding; pulmonary arterial hypertension; receptor

DESCRIPTION: None of the established therapies for patients with Pulmonary Arterial Hypertension (PAH) reduce mortality or reverse established pulmonary vasculopathy. However, patients with Hereditary PAH (HPAH) inherit heterozygous, autosomal dominant mutations in the BMP type 2 receptor gene, BMPR2, suggesting that strategies to correct BMP signaling defects could present a new therapeutic approach for this disease. Over 300 HPAH BMPR2 mutations have been identified, each with potentially different effects on BMPR2 function. However, these can be classified into 3 functional groups: i) Class I: mRNA is degraded by non-sense mediated RNA decay, (NMD+); ii) Class II: receptors are expressed (NMD-), but mis-folded and are not expressed on the cell surface; and iii) Class III: receptors are expressed (NMD-) and correctly localized but non functional. This classification is important since NMD inhibitors may restore BMP signaling with Class I mutations, while compounds that correct protein folding may restore signaling with Class II but not Class III BMPR2 mutations. Importantly, both NMD inhibitors and protein folding agents, are effective, safe and being evaluated in patients with other heritable diseases, such as cystic fibrosis. These studies will determine whether mutation-specific therapies also correct BMPR2 expression and function in HPAH patients. As an initial step to establish the applicability of this paradigm in HPAH, we will use HPAH patient-derived endothelial cells (ECs). Ideally we would use pulmonary endothelial cells (PECs) from HPAH patients for all of these studies. However these cells are in limited supply and have short lifespan in culture. For this reason we will supplement initial studies using HPAH PECs obtained from the PHBI Cell Core, with studies using late outgrowth endothelial progenitor cells (LEPCs) obtained from peripheral blood of HPAH patients with known BMPR2 mutations. Some of these cells have been generated and will be provided by a collaborator. However, we are in a unique position at Vanderbilt to supplement these studies using samples derived from the largest cohort of HPAH patients with defined BMPR2 mutations in the USA. In this way we will be able to study a cohort of HPAH patient-derived ECs that include a representative distribution of BMPR2 mutations from all 3 functional classes of mutation. Using these cells therefore, we will determine the nature and functional classification of BMPR2 mutations, and evaluate the effects of NMD pathway inhibitors and protein folding agents on BMPR2 expression and function in these HPAH patients. These studies therefore will identify BMPR2 mutant sub-types and responsiveness to NMD pathway or protein folding therapy in a relevant cell type, and will form the foundation to classify therapeutically targetable BMPR2 mutations and more extensive evaluation of NMD inhibitors and/or protein folding agents in HPAH. PUBLIC HEALTH RELEVANCE: Pulmonary Arterial Hypertension is an invariably fatal disease for which there is no curative treatment. A major challenge for the scientific community therefore is to develop therapeutic approaches to prevent the progression of pulmonary vascular disease that develops in these patients. Our studies will provide important insight into a common pathway that regulates this process and identify approaches to interfere with this pathway and prevent the development of irreversible pulmonary vascular disease in these patients. (End of Abstract)

描述：针对肺动脉高压 (PAH) 患者的现有治疗方法均无法降低死亡率或逆转已确定的肺血管病变。然而，遗传性 PAH (HPAH) 患者遗传了 BMP 2 型受体基因 BMPR2 的杂合常染色体显性突变，这表明纠正 BMP 信号缺陷的策略可能为该疾病提供一种新的治疗方法。已鉴定出超过 300 种 HPAH BMPR2 突变，每种突变对 BMPR2 功能都有潜在不同的影响。然而，这些可以分为 3 个功能组： i) I 类：mRNA 通过无义介导的 RNA 衰减而降解，(NMD+)； ii) II类：受体被表达（NMD-），但错误折叠并且不在细胞表面表达； iii) III 类：受体表达（NMD-）并正确定位，但无功能。这种分类很重要，因为 NMD 抑制剂可能会恢复 I 类突变的 BMP 信号传导，而纠正蛋白质折叠的化合物可能会恢复 II 类突变的 BMP 信号传导，但不能恢复 III 类 BMPR2 突变的信号传导。重要的是，NMD 抑制剂和蛋白质折叠剂都是有效、安全的，并且正在患有其他遗传性疾病（例如囊性纤维化）的患者中进行评估。这些研究将确定突变特异性疗法是否也能纠正 HPAH 患者的 BMPR2 表达和功能。作为建立该范例在 HPAH 中适用性的第一步，我们将使用 HPAH 患者来源的内皮细胞 (EC)。理想情况下，我们将使用来自 HPAH 患者的肺内皮细胞 (PEC) 进行所有这些研究。然而，这些细胞的供应有限，并且在培养物中的寿命很短。因此，我们将补充使用从 PHBI Cell Core 获得的 HPAH PEC 的初步研究，以及使用从具有已知 BMPR2 突变的 HPAH 患者外周血中获得的晚期生长内皮祖细胞 (LEPC) 的研究。其中一些单元已生成并将由合作者提供。然而，我们在范德比尔特大学处于独特的地位，可以使用来自美国最大的具有明确 BMPR2 突变的 HPAH 患者群体的样本来补充这些研究。通过这种方式，我们将能够研究一组源自 HPAH 患者的 EC，其中包括来自所有 3 个功能突变类别的 BMPR2 突变的代表性分布。因此，利用这些细胞，我们将确定 BMPR2 突变的性质和功能分类，并评估 NMD 途径抑制剂和蛋白折叠剂对这些 HPAH 患者中 BMPR2 表达和功能的影响。因此，这些研究将确定相关细胞类型中的 BMPR2 突变亚型以及对 NMD 途径或蛋白折叠疗法的反应，并将形成对治疗靶向 BMPR2 突变进行分类以及对 NMD 抑制剂和/或蛋白折叠剂进行更广泛评估的基础。肺动脉高压。 公共卫生相关性：肺动脉高压是一种无法治愈的致命疾病。因此，科学界面临的一个主要挑战是开发治疗方法来预防这些患者发生的肺血管疾病的进展。我们的研究将为调节这一过程的共同途径提供重要的见解，并确定干扰该途径并防止这些患者发生不可逆肺血管疾病的方法。 （摘要完）