Golgi Blockade in Pulmonary Hypertension

描述(申请人提供)：肺动脉高压(PH)是一种进行性疾病，发病率和死亡率都很高，BMPR2基因突变是这种疾病的易感因素。在人类和实验模型中，这种疾病的亚细胞改变的一个特点是，在肺动脉病变中，增大的空泡状内皮细胞和平滑肌细胞伴随内质网和高尔基体增多(巨细胞增多症)。我们在亚细胞水平上提出了一种新的致病机制--细胞内转运功能障碍(高尔基阻断假说)。我们将使用体内衍生材料和细胞培养实验，在人类PH和实验模型(野百合碱、缺氧、BMPR2R899X突变)中研究这一机制。可预测的后果包括囊泡拴系物、陷阱和断裂在高尔基体中的捕获，N-乙基马来酰亚胺(NSF)的亚细胞定位错误，以及eNOS和血管相关生长因子受体等货物的错误定位(SNAREing肺动脉高压)，远端后果包括细胞因子和生长因子信号增强，促有丝分裂信号和DNA合成，抗凋亡，细胞尺寸增大和细胞迁移，从而减少血管腔。在目标1(体内研究)中，我们将高尔基体阻断假说与人特发性PH的病理生理学、大鼠的野百合碱和低氧模型以及BMPR2 R899X转基因小鼠的PH的病理生理学联系起来。在目标2(细胞培养研究)中，我们将研究MCTP、低氧和BMPR2突变导致高尔基体阻断和细胞内转运缺陷的启动机制，重点是NSF和涉及的近端机制事件。在目标3(细胞培养研究)中，我们将研究MCTP、低氧和BMPR突变体破坏细胞内转运的一些远端转运后果。与公共卫生相关。肺动脉高压(PH)是一种进行性致命的人类肺部疾病。我们提出了一种全新的方式来思考这种致命疾病的原因。我们认为，由于处理这些细胞内蛋白质运动的细胞机制的缺陷，排列在肺内动脉血管内的内皮细胞和平滑肌细胞变得更大，数量增加。这会导致血管堵塞。拟议的机制为如何治疗这种疾病开辟了新的思路。

DESCRIPTION (provided by applicant): Pulmonary hypertension (PH) is a progressive disease with high morbidity and mortality with mutations in BMPR2 a predisposing factor in this disease. A hallmark of the subcellular alterations in this disease, in man and in experimental models, includes enlarged vacuolated endothelial and smooth muscle cells with increased endoplasmic reticulum and Golgi stacks ("megalocytosis") in pulmonary arterial lesions. We propose a novel disease-initiating mechanism at the subcellular level - a dysfunction of intracellular trafficking (the Golgi blockade hypothesis). We shall investigate this mechanism in human PH and in experimental models (monocrotaline, hypoxia, BMPR2R899X mutation) using in vivo-derived materials and in experiments in cell culture. Predicted consequences include trapping of vesicle tethers, SNAREs and SNAPs in the Golgi and subcellular mislocalization of N-ethylmaleimide sensitive factor (NSF), and of cargo such as eNOS and vasorelevant growth factor recetors (SNAREing pulmonary hypertension), Distal consequences include enhanced cytokine and growth factor signaling, promitogenic signaling and DNA synthesis, resistance to apoptosis, increased cell size and cell migration and thus reduction of the vascular lumen. In Aim 1 (in vivo studies) we shall link the Golgi blockade hypothesis to the pathophysiology of idiopathic PH in man, in the monocrotaline and hypoxia models of PH in the rat, and in the BMPR2 R899X transgenic mouse. In Aim 2 (cell culture studies) we shall investigate the initiation mechanisms that lead to Golgi blockade and defects in intracellular trafficking in response to MCTP, hypoxia and BMPR2 mutants with a focus on NSF and the proximal mechanistic events involved. In Aim 3 (cell culture studies) we shall investigate some of the distal trafficking consequences of disruption of intracellular trafficking by MCTP, hypoxia and BMPR mutants. PUBLIC HEALTH RELEVANCE. Pulmonary arterial hypertension (PH) is a progressive fatal lung disease in man. We propose an all together novel way of thinking about the cause of this fatal disease. We suggest that the endothelial and smooth muscle cells that line the arterial blood vessels in the lung become bigger and increase in number because of a defect in cellular machinery that handles the movement of proteins within these cells. This leads to a blockage of the blood vessels. The proposed mechanism opens up new ways of thinking about how to treat this disease.