Genomic and proteomic dissection of the molecular basis of kidney development.

成人肾脏中存在的肾单位数量可以变化三倍。这可能是由于在发育过程中肾元形成速率的微小变化。越来越多的证据表明，由于高血压或药物滥用等压力，肾单位数量减少可能会导致晚年肾功能衰竭。美国每年新增80,000例终末期肾衰竭病例，其中25%与高血压有关，因此可能与肾单位数量低有关。虽然已知肾脏是通过后肾间质和输尿管芽之间的一系列相互诱导事件产生的，但需要更好地了解这些事件的分子基础，以了解决定肾元禀赋的因素。Wilms肿瘤抑制蛋白WT1不仅在儿童肾癌（Wilms肿瘤）的某些病例中发生突变，而且对后肾的正常发育也至关重要，正如在小鼠中进行的敲除实验所证明的那样。WT1是后肾间质中最早表达的基因之一，被认为可以防止后肾组织在分化前死亡，指导其形成肾脏，并在出生后调节正常足细胞功能。虽然已知WT1是一种核调控蛋白，但对其直接调控的基因还没有明确而令人信服的描述。本研究旨在直接筛选WT1诱导的基因表达和蛋白产生水平的变化。为此，将使用一种独特的阵列方法，使用来自发育中的肾脏的特定阵列集。同时，将构建和分析肾元形成开始前和开始后小鼠肾脏的其他特异性克隆集。由于WT1是一种参与剪接的核蛋白，本研究将在蛋白质组学水平上平行研究剪接体蛋白随WT1变化的变化。

The number of nephrons present in the human adult kidney can vary by threefold. This is likely to be due to slight variations in the rate of nephron formation during development. Evidence is mounting that a reduced number of nephrons can predispose to renal failure later in life in response to stresses such as hypertension or substance abuse. 80,000 new cases of end stage renal failure occur each year in the US, with 25% of these related to hypertension and therefore possibly linked to a low nephron number. While it is known that the kidney arises through a series of reciprocal inductive events between the metanephric mesenchyme and the ureteric bud, a better understanding of the molecular basis of these events is needed to understand what dictates nephron endowment. The Wilms tumour suppressor protein WT1 is not only mutated in some cases of the childhood kidney cancer, Wilms tumour, but is also critical for the normal development of the metanephros, as demonstrated by knockout experiments in mice. One of the earliest genes expressed in the metanephric mesenchyme, WT1 is thought to prevent this tissue from dying before differentiation, directing it to form the kidney and, postnatally, regulating normal podocyte function. Although known to be a nuclear regulatory protein, the genes directly regulated by WT1 have not been clearly or convincingly delineated. This study aims to directly screen for changes to gene expression and protein production levels induced by WT1. To do so, an array approach unique in its use of a specific array set derived from developing kidney will be used. In concert, additional specific clone sets derived from mouse kidney prior and post the commencement of nephron formation will be constructed and analysed. As WT1 is a nuclear protein involved in splicing, this study will involve a parallel investigation at a proteomic level of changes in spliceosomal proteins in response to changes in WT1.