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

人类成人肾脏中存在的肾单位数量可能会有三倍的差异。这可能是由于发育过程中肾单位形成率的微小差异。越来越多的证据表明，在应对高血压或药物滥用等压力时，肾单位数量的减少可能会在晚年容易导致肾功能衰竭。美国每年发生80,000例终末期肾功能衰竭新病例，其中25%与高血压有关，因此可能与低肾单位数量有关。虽然已知肾脏是通过后肾间充质和输尿管芽之间的一系列相互诱导事件而产生的，但需要更好地了解这些事件的分子基础，以了解是什么决定了肾单位的天赋。Wilms肿瘤抑制蛋白WT1不仅在某些儿童肾癌Wilms肿瘤中发生突变，而且在小鼠的基因敲除实验中证明，WT1对后肾的正常发育也至关重要。WT1是最早在后肾间充质中表达的基因之一，被认为可以防止后肾间充质在分化前死亡，引导它形成肾脏，并在出生后调节正常的足细胞功能。尽管已知WT1是一种核调节蛋白，但WT1直接调控的基因还没有被清楚或令人信服地描绘出来。这项研究旨在直接筛选WT1诱导的基因表达和蛋白质生产水平的变化。为了做到这一点，将使用一种独特的阵列方法，它使用的是从发育中的肾脏获得的特定阵列集。同时，还将构建和分析在肾单位形成开始之前和之后从小鼠肾脏获得的额外的特定克隆集。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.