Extracellular determinants of polycystic kidney disease severity

多囊肾病严重程度的细胞外决定因素

• 批准号: 8479351
• 负责人: MYRON E HINSDALE
• 金额: $ 29.69万
• 依托单位: OKLAHOMA STATE UNIVERSITY STILLWATER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-15 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8479351
• 关键词: Adult; Aging; Agrin; Anabolism; Animal Model; Animals; Area; Autosomal Recessive Polycystic Kidney; Biliary; Biological Assay; Biology; Caring; Caroli Disease; Cell Proliferation; Cells; Clinical; Complex; Controlled Study; Core Protein; Cyst; Cystic Lesion; Cystic kidney; Data; Development; Disease model; End stage renal failure; Epithelial Cells; Extracellular Matrix; Functional disorder; Gene-Modified; Genetic; Glycosaminoglycans; Goals; Hepatic Cyst; Hyperplasia; Hypertension; Immunohistochemistry; Investigation; Kidney; Kidney Failure; Knowledge; Lead; Lesion; Life; Liver; Liver Fibrosis; Luciferases; Magnetic Resonance Imaging; Measures; Mediating; Methods; Molecular; Morbidity - disease rate; Mus; Mutation; Neonatal; Organ; Outcome; PKD2 protein; Pathogenesis; Pathology; Pathway interactions; Patients; Phenotype; Play; Polycystic Kidney Diseases; Portal Hypertension; Process; Proteinuria; Proteoglycan; Public Health; Regulation; Renal function; Reporter; Research; Research Proposals; Rodent Model; Role; Severities; Severity of illness; Signal Pathway; Signal Transduction; Survivors; Testing; Tissues; Translating; Variant; Wild Type Mouse; base; biliary tract; clinical phenotype; early onset; extracellular; improved; innovation; mortality; mouse model; novel; perlecan; polycystic kidney disease 1 protein; public health relevance; xylosyltransferase

DESCRIPTION (provided by applicant): Little is understood about the genetic modifiers that are responsible for a wide range of complications that afflict autosomal recessive polycystic kidney disease (ARPKD) patients. Understanding what these genetic modifiers are, how they disrupt organ function, and how they aggravate ARPKD, will lead to more effective and tailored therapies aimed at ameliorating patient suffering. Experimental results strongly suggest that reduced proteoglycans (PGs) are modifiers of PKD lesion severity. Therefore, the broad long-term goal of our research group is to identify the responsible PGs and determine their role in the pathogenesis of PKD with the intent of developing targeted treatments that reduce lesion severity. In pursuit of this goal, our investigations have identified several PGs in liver that when lacking glycosaminoglycans are candidates for cyst development. Based on extensive preliminary data, this application's central hypothesis is that reduced PG levels are important modifiers of cyst development and can augment ARPKD cyst development and progression mediated by increased canonical Wnt/?-catenin pathway activity. The overall objective of this application, as a first step towards our long-term goal, is to test this hypothesis with the following aims: 1) To determine the impact of reduced PG on the development of liver and renal cysts in an ARPKD mouse model with decreased FC activity and loss of XylT2 activity. Cyst development, severity, and lesional ?-catenin levels in these mice will be measured using comprehensive histological methods and magnetic resonance imaging; 2) To determine the role that PGs have in renal cyst development by creating adult Xylt2-/- mice that have significantly reduced renal PGs. Renal function, cystic development, and glycosaminoglycan content will be assessed in the resultant mice and compared to controls; 3) To determine the importance of recently identified candidate PGs in the regulation of Wnt/?- catenin signaling in cultured biliary tracts and in isolated biliary epithelial cells. Wild type and Xylt2-/- cells and biliary tracts will be cultured under conditions of increased Wnt/?-catenin activation in the presence of core protein with and without glycosaminoglycans. Wnt/?-catenin signaling will be assessed by luciferase reporter assays and by immunohistochemistry for pathway intermediates and correlated with cellular proliferation and cyst development. The rationale of the proposed research is based on the assumption that understanding the molecular mechanism of ARPKD lesion modifiers will translate into fundamental improvements in understanding PKD lesion development. Thus the proposed research is relevant to PA-07- 293 in regards to defining "the function of molecules and pathways that cause, aggravate or ameliorate PKD" and identifying "in rodent models...specific genes that modify the clinical phenotype." The proposed research is significant because the identification of genetic modifiers and understanding their impact on clinical variation is expected to advance individualized ARPKD patient treatment and prognostication.

描述（由申请人提供）：对于常染色体隐性多囊肾病（ARPKD）患者的各种并发症的遗传修饰因子知之甚少。了解这些基因修饰因子是什么，它们是如何破坏器官功能的，以及它们是如何加重ARPKD的，将导致更有效和量身定制的治疗方法，旨在改善患者的痛苦。实验结果强烈提示还原性蛋白多糖（PGs）是PKD病变严重程度的调节剂。因此，我们研究小组广泛的长期目标是确定相关的pg，并确定它们在PKD发病机制中的作用，目的是开发降低病变严重程度的靶向治疗方法。为了实现这一目标，我们的研究已经确定了几种肝脏中的pg，当缺乏糖胺聚糖时，它们是囊肿发展的候选者。基于广泛的初步数据，本申请的中心假设是PG水平的降低是囊肿发展的重要调节剂，并且可以增加ARPKD囊肿的发展和进展，而典型Wnt/？-catenin通路活性。作为我们实现长期目标的第一步，本应用的总体目标是通过以下目的来验证这一假设：1)在FC活性降低和XylT2活性丧失的ARPKD小鼠模型中，确定PG减少对肝脏和肾脏囊肿发展的影响。囊肿的发展、严重程度和病变？-catenin在这些小鼠中的水平将通过综合组织学方法和磁共振成像来测量；2)通过建立显著降低肾pg的成年Xylt2-/-小鼠，确定pg在肾囊肿发育中的作用。将对所得小鼠的肾功能、囊性发育和糖胺聚糖含量进行评估，并与对照组进行比较；3)确定最近发现的候选PGs在Wnt/？-培养的胆道和分离的胆道上皮细胞中的连环蛋白信号传导。野生型和Xylt2-/-细胞和胆道将在Wnt/？-catenin在核心蛋白存在和不存在糖胺聚糖的情况下的活化。Wnt / ?-catenin信号将通过荧光素酶报告基因检测和途径中间体的免疫组织化学来评估，并与细胞增殖和囊肿发展相关。本研究的基本原理是基于这样的假设，即了解ARPKD病变调节剂的分子机制将从根本上改善对PKD病变发展的理解。因此，在确定“导致、加重或改善PKD的分子和途径的功能”以及在啮齿动物模型中识别“PKD”方面，所提出的研究与PA-07- 293相关。改变临床表型的特定基因。”这项研究具有重要意义，因为确定遗传修饰因子并了解其对临床变异的影响有望推进个体化ARPKD患者治疗和预后。