DECIPHERING ROLES OF GDNF-GFRA1 RET SIGNALING IN NORMAL AND INJURED KIDNEY

解读 GDNF-GFRA1 RET 信号在正常和受损肾脏中的作用

• 批准号: 7773521
• 负责人: Sanjay Jain
• 金额: $ 28.14万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-02-20 至 2012-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7773521
• 关键词: Acute; Acute Kidney Failure; Acute Renal Failure with Renal Papillary Necrosis; Adult; Affect; Animal Model; Apoptosis; Area; Biological; Biology; Brain; Cell Death; Cell Differentiation process; Cell Line; Cell physiology; Cells; Characteristics; Chronic; Defect; Development; Disease; Dose; Economic Burden; Event; Family; Genes; Genetically Engineered Mouse; Genitourinary system; Glean; Health; Human; Injury; Injury to Kidney; Kidney; Kidney Diseases; Kidney Failure; Knockout Mice; Lead; Ligands; Maintenance; Mesenchyme; Metanephric Diverticulum; Methods; Modeling; Molecular; Morbidity - disease rate; Mus; Natural regeneration; Neonatal; Neural Crest; Neurodegenerative Disorders; Neuroglia; Parkinson Disease; Pathogenesis; Pathway interactions; Patients; Phenocopy; Physiological; Physiology; Proteins; Receptor Protein-Tyrosine Kinases; Renal function; Reperfusion Injury; Reporter; Role; Scientist; Serological; Severities; Signal Pathway; Signal Transduction; Site; Societies; Stem cells; Stress; System; Testing; Therapeutic; Therapeutic Effect; Therapy Clinical Trials; Time; Tissues; Toxin; Transgenic Mice; Wild Type Mouse; base; body system; cell type; gene function; glial cell-line derived neurotrophic factor; human disease; injured; insight; interest; kidney preservation; mortality; mouse model; nephrogenesis; neurotrophic factor; novel; postnatal; progenitor; public health relevance; receptor; repaired; response; spatiotemporal; tool

DESCRIPTION (provided by applicant): Congenital, chronic and acute kidney diseases cause significant morbidity, mortality and economic burden to our society. A significant impact in all these areas will be made by identifying pathogenetic mechanisms that cause kidney diseases. Because humans and mice share a number of characteristics of kidney development and function, and animal models of renal injury recapitulate events that are similar to humans, genetically engineered mouse models offer an important tool to delineate molecular mechanisms of renal diseases. A prevailing idea is that a number of these conditions are caused by aberrant function of genes that are also important in early kidney formation. Because absence of these genes from the beginning of kidney development often results in renal or other abnormalities and lethality, there is scarcity of animal models to examine the role of these genes in kidney disease in adulthood. Glial cell line-derived neurotrophic factor (GDNF), its coreceptor Gfra1 and receptor Ret constitute a signaling system that is critical for kidney development. It also regulates function of several tissue specific progenitors and is implicated in repair, regeneration and therapy of a number of conditions. However, biological roles of this signaling system in the postnatal kidney in normal and abnormal conditions are not known since its absence results in renal agenesis and lethality. We hypothesize that GDNF-Gfra1-Ret signaling is required for kidney maintenance in adult mice, it is important in kidney protection and regeneration after acute kidney injury (AKI), and GDNF can protect kidneys from AKI due to different types of insults by acting through Gfra1-Ret pathway. We have generated a number of animal models that are necessary to test these hypotheses. For example, to overcome lethality we have developed unique mouse models that will inactivate Gfra1 or Ret signaling after initial kidney development (conditional mice). To identify Gfra1 or Ret expressing cells in normal and disease states, we have generated "reporter" mice. To determine therapeutic potential of GDNF, we have established systemic delivery method that has shown protection in ischemic-reperfusion injury to the brain. The objective of specific Aim 1 in this proposal will be to use GDNF, Gfra1 and Ret reporter mice to identify where these proteins are expressed in the normal postnatal kidney and how their expression changes during AKI particularly in relation to repair and regeneration. In Specific Aim 2 we will use Gfra1 and Ret conditional mice to determine the impact of their loss on normal renal function in adult mice, and in AKI. In Aim 3, we will determine if exogenous treatment with GFLs in different AKI models is renoprotective, stimulates regeneration and occurs through Gfra1. Through these studies we will determine the importance of this pathway in renal health and disease. The insights gleaned will be of interest to a broad group of basic scientist, clinicians and patients affected by renal diseases. PUBLIC HEALTH RELEVANCE: GDNF-Gfra1-Ret signaling pathway is critical for kidney development and regulates function of a number of tissue specific stem cells. In this proposal we will utilize novel animal models to modulate this pathway and determine its role in the function of postnatal kidney in normal and disease states and examine if treatment with GDNF can protect kidneys from renal failure. The studies will provide novel insights into mechanisms of repair and regeneration and therapy in injured kidneys.

描述（由申请人提供）：先天性、慢性和急性肾脏疾病给我们的社会造成显著的发病率、死亡率和经济负担。通过确定导致肾脏疾病的发病机制，将对所有这些领域产生重大影响。由于人类和小鼠共享肾脏发育和功能的许多特征，并且肾损伤的动物模型重现了与人类相似的事件，因此基因工程小鼠模型提供了描述肾脏疾病分子机制的重要工具。一个流行的观点是，许多这些条件是由基因的异常功能引起的，这些基因在早期肾脏形成中也很重要。由于从肾脏发育开始缺乏这些基因通常会导致肾脏或其他异常和致死性，因此缺乏动物模型来检查这些基因在成年期肾脏疾病中的作用。胶质细胞源性神经营养因子（GDNF），其共同受体Gfra 1和受体Ret构成了一个信号系统，是肾脏发育的关键。它还调节几种组织特异性祖细胞的功能，并涉及许多病症的修复、再生和治疗。然而，在正常和异常条件下，这种信号系统在出生后肾脏中的生物学作用尚不清楚，因为它的缺乏会导致肾脏发育不全和死亡。我们推测GDNF-Gfra 1-Ret信号通路是成年小鼠肾脏维持所必需的，在急性肾损伤（阿基）后肾脏保护和再生中起重要作用，GDNF通过Gfra 1-Ret通路发挥作用，保护肾脏免受不同类型损伤的损伤。我们已经建立了一些动物模型，这些模型是检验这些假设所必需的。例如，为了克服致死性，我们开发了独特的小鼠模型，其将在初始肾脏发育后抑制Gfra 1或Ret信号传导（条件小鼠）。为了鉴定在正常和疾病状态下表达Gfra 1或Ret的细胞，我们产生了“报告”小鼠。为了确定GDNF的治疗潜力，我们已经建立了全身递送方法，该方法在脑缺血再灌注损伤中显示出保护作用。本提案中具体目标1的目的是使用GDNF、Gfra 1和Ret报告基因小鼠来鉴定这些蛋白质在正常出生后肾脏中的表达位置，以及它们在阿基期间的表达变化，特别是与修复和再生相关的变化。在特定目标2中，我们将使用Gfra 1和Ret条件性小鼠来确定其丧失对成年小鼠和阿基中正常肾功能的影响。在目标3中，我们将确定在不同的阿基模型中使用GFL进行外源性治疗是否具有肾脏保护作用、刺激再生并通过Gfra 1发生。通过这些研究，我们将确定这一途径在肾脏健康和疾病中的重要性。所收集的见解将引起广泛的基础科学家，临床医生和受肾脏疾病影响的患者的兴趣。公共卫生关系：GDNF-Gfra 1-Ret信号通路对肾脏发育至关重要，并调节许多组织特异性干细胞的功能。在这项研究中，我们将利用新的动物模型来调节这一途径，并确定其在正常和疾病状态下的出生后肾脏功能中的作用，并研究GDNF治疗是否可以保护肾脏免受肾功能衰竭的影响。这些研究将为损伤肾脏的修复和再生机制以及治疗提供新的见解。