PKD1-Fibrillin Interactions and TFG-b Signaling Pathways

PKD1-原纤维蛋白相互作用和 TFG-b 信号通路

• 批准号: 7136921
• 负责人: Terry J Watnick
• 金额: $ 30.66万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7136921
• 关键词: Marfan syndrome; alleles; aorta; aorta disorder; autosomal dominant trait; biological signal transduction; blood vessel disorder; calcium channel; family genetics; fibrillin; gene interaction; genetically modified animals; histopathology; laboratory mouse; medical complication; molecular pathology; pathologic process; polycystic kidney; protein protein interaction; protein signal sequence; transcription factor; transforming growth factors

DESCRIPTION (provided by applicant): Autosomal dominant polycystic kidney disease (ADPKD) is the most common form of inherited renal failure in the US. Although the disease is named for its most notable feature, namely kidney cysts, vascular complications are in fact a significant cause of morbidity and mortality. Based on the association of aneurysms and ADPKD it has been speculated that polycystins (PKD proteins) play an important role in maintaining vascular integrity of blood vessels but the precise cellular function of polycystins in the vasculature has not been defined. In support of this hypothesis, animals with mutations in either PKD gene die in utero and often exhibit hemorrhage with leaky blood vessels and edema. Despite the significance of this problem, the precise cellular function of polycystins in the vasculature has not yet been defined. We believe that exciting new clues may come from the relationship between PKD and connective tissue diseases such as Marfan syndrome (MFS) that also have a prominent vascular phenotype. Until recently it was assumed that the pathogenic mechanism underlying the MFS phenotype had to do with the structural failure of the ECM. However, recent work suggests that over activity of TGF-beta signaling may play a role in disease pathogenesis. The observation that families with ADPKD and MFS have overlapping clinical features prompted us to test for a functional interaction between 2 gene products. Our preliminary studies demonstrate that mice which are heterozygous for mutations in Pkd1 and the MFS gene, Fbn1, have a remarkable increase in the aortic wall pathology as well as evidence of increased TGF-beta signaling. This application seeks to define the mechanism that is responsible for this genetic interaction. In the first aim we will test the hypothesis that loss of a Pkd1 or Pkd2 allele results in worsening of the histopathologic features of MFS. The goal of Aim 2 is to understand how Fbn1 and Pkd1 cooperatively modulate TGF-beta signaling. We will use a variety of histochemical, cell culture and in vivo methods to interrogate the TGF-beta signaling. Aim 3 will extend these studies by asking whether Pkd1 affects TGF-beta signaling via STAT-1 dependent induction of the inhibitory SMAD7. Aim 4 will test the hypothesis that disruption of the Pkd1 alone results in a vascular phenotype and that is associated with the dysregulation of TGF-beta superfamily signaling. We anticipate that an improved understanding of vascular signaling pathways in ADPKD will result in therapeutic approaches that could be applied to the treatment or prevention of some of the most devastating consequences of this disease. We propose the following specific aims: Specific Aim 1: Elucidate the pathogenesis of the aortic phenotype in mice carrying compound heterozygous Pkd/Fbn mutations. Specific Aim 2: Interrogate the TGF-B signaling pathway in Pkd/Fbn Compound Heterozygotes. Specific Aim 3: Test the hypothesis that PKD1 affects TGF-B signaling via STAT-1 dependent induction of the inhibitory SMAD7. Specific Aim 4: Test the hypothesis that disruption of Pkd1 is sufficient to modulate TGF-B related signaling pathways.

描述（由申请人提供）：常染色体显性多囊性肾脏疾病（ADPKD）是美国遗传肾衰竭最常见的形式。尽管该疾病以其最著名的特征命名，即肾脏囊肿，但血管并发症实际上是发病率和死亡率的重要原因。基于动脉瘤和ADPKD的关联，已经推测多囊这（PKD蛋白）在维持血管的血管完整性方面起着重要作用，但是尚未确定多囊蛋白在血管中的精确细胞功能。为了支持这一假设，pKD基因在子宫内死亡的动物经常出血，血管和水肿出血。尽管该问题具有重要意义，但尚未定义多囊菌素在脉管系统中的精确细胞功能。我们认为，令人兴奋的新线索可能来自PKD与结缔组织疾病（例如Marfan综合征（MFS））之间的关系，这些疾病也具有突出的血管表型。直到最近，假定MFS表型基础的致病机制与ECM的结构衰竭有关。但是，最近的工作表明，TGF-β信号的活性过多可能在疾病发病机理中起作用。 ADPKD和MF的家庭具有重叠的临床特征的观察，促使我们测试了2种基因产物之间的功能相互作用。我们的初步研究表明，PKD1突变和MFS基因FBN1的突变杂合的小鼠在主动脉壁病理学以及TGF-beta信号增加的证据中具有显着增加。该应用程序旨在定义负责这种遗传相互作用的机制。在第一个目的中，我们将检验以下假设：PKD1或PKD2等位基因的丧失会导致MFS的组织病理学特征恶化。 AIM 2的目标是了解FBN1和PKD1如何协同调节TGF-beta信号传导。我们将使用各种组织化学，细胞培养和体内方法来询问TGF-β信号。 AIM 3将通过询问PKD1是否通过抑制性SMAD7的STAT-1依赖性诱导影响TGF-β信号传导来扩展这些研究。 AIM 4将检验以下假设：仅PKD1的破坏会导致血管表型，并且与TGF-Beta超家族信号传导的失调有关。我们预计，对ADPKD中血管信号通路的了解得以提高，将导致治疗方法可用于治疗或预防该疾病的某些最具毁灭性后果。我们提出以下特定目的：特定目标1：阐明携带复合杂合PKD/FBN突变的小鼠中主动脉表型的发病机理。具体目标2：询问PKD/FBN化合物杂合子中的TGF-B信号通路。具体目标3：检验PKD1通过STAT-1依赖性抑制SMAD7影响TGF-B信号传导的假设。具体目标4：检验PKD1破坏足以调节TGF-B相关信号通路的假设。