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: 8115217
• 负责人: MYRON E HINSDALE
• 金额: $ 30.86万
• 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/8115217
• 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; 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. PUBLIC HEALTH RELEVANCE: There is no cure for any form of polycystic kidney disease, and although many patients develop kidney failure due to cystic change, they also suffer variably from other clinical complications. Despite experimental evidence that proteoglycans are an important component of the cystic lesion and possible modifiers of its severity, little is understood about what role they may have in polycystic kidney disease pathogenesis. Understanding the role of proteoglycans in lesion severity has the potential to advance public health by expanding the fundamental knowledge of cyst development, unraveling the mystery of high clinical variability, and improving patient treatment.

描述（由申请人提供）：对常染色体隐性遗传性多囊肾病（ARPKD）患者广泛并发症的遗传修饰剂了解甚少。了解这些遗传修饰剂是什么，它们如何破坏器官功能，以及它们如何加重ARPKD，将导致旨在改善患者痛苦的更有效和量身定制的疗法。实验结果强烈表明，减少蛋白聚糖（PG）是PKD病变严重程度的修饰剂。因此，我们研究小组的广泛长期目标是确定负责的PG并确定其在PKD发病机制中的作用，旨在开发降低病变严重程度的靶向治疗。为了实现这一目标，我们的研究已经确定了肝脏中的几种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水平降低是囊肿发育的重要调节剂，并且可以增加由增加的典型Wnt/β介导的ARPKD囊肿发育和进展。连环蛋白通路活性。本申请的总体目的，作为实现我们长期目标的第一步，是用以下目的来检验该假设：1）确定降低的PG对FC活性降低和XylT 2活性丧失的ARPKD小鼠模型中肝和肾囊肿发展的影响。囊肿的发展，严重程度和病变？使用综合组织学方法和磁共振成像测量这些小鼠中的连环蛋白水平; 2）通过产生具有显著减少的肾PG的成年Xylt 2-/-小鼠来确定PG在肾囊肿发展中的作用。将在所得小鼠中评估肾功能、囊性发育和糖胺聚糖含量，并与对照组进行比较; 3）为了确定最近鉴定的候选PG在Wnt/β调节中的重要性，在培养的胆管和分离的胆管上皮细胞中的连环蛋白信号传导。野生型和Xylt 2-/-细胞和胆道将在Wnt/β增加的条件下培养。在有和没有糖胺聚糖的情况下，在核心蛋白存在下的连环蛋白活化。Wnt/？-通过荧光素酶报告基因测定和通过免疫组织化学对途径中间体进行评价，并将其与细胞增殖和囊肿发育相关联。拟议研究的基本原理是基于这样的假设，即理解ARPKD病变修饰剂的分子机制将转化为理解PKD病变发展的根本改善。因此，拟议的研究与PA-07- 293相关，涉及定义“导致、加重或改善PKD的分子和途径的功能”，并确定“在啮齿动物模型中......修饰临床表型的特定基因。“拟议的研究是重要的，因为遗传修饰剂的识别和了解其对临床变异的影响，预计将推进ARPKD患者的个性化治疗和辅助治疗。 公共卫生相关性：多囊肾是一种常见的肾脏疾病，它的病因是肾功能不全、肾功能不全。尽管有实验证据表明蛋白多糖是囊性病变的重要组成部分，并可能改变其严重程度，但对它们在多囊肾病发病机制中的作用知之甚少。了解蛋白聚糖在病变严重程度中的作用，有可能通过扩大囊肿发展的基础知识，揭开高临床变异性的奥秘，并改善患者治疗，从而促进公共卫生。