Regulation of Kidney-Specific Gene Expression

摘要 本次价值更新的目的是为了继续我们对肝细胞核因子-1β(hnf-1β)及其受体的研究。 在肾脏特异性基因表达和囊性肾脏疾病中的作用Hnf-1β是一种dna结合转录。 调节肾脏和其他上皮性器官中组织特异性基因表达的因子。人类神经营养因子的突变- 1β可导致先天性肾脏和尿路畸形，囊性肾病，常染色体显性遗传 肾小管间质肾病和遗传性肾小管病变。为了揭开这些疾病的发病机制， 我们已经培育出了hnf-1β突变小鼠，它们的表型与受影响的人类相似。 对突变小鼠的分析表明，hnf-1β在多囊肾的表达中起核心作用。 疾病基因，如PKD2和PKHD1。在上一个项目期间，我们使用了全基因组芯片和 Rna-seq用于识别由hnf-1β直接调控的转录网络。与新的突变体一起 小鼠模型，这些研究揭示了hnf-1β在Wnt信号和cAMP调节中的新作用 信号、脂代谢、尿液浓度和非编码RNA的表达。初步研究使用 质谱仪显示hnf-1β与染色质重塑、组蛋白等相关蛋白相互作用。 修饰和转录延伸。在下一个项目期间，我们将扩展这项工作，以进一步拆解 肾组织中hnf-1β的功能特殊目标1将使用生物化学研究来解开分子 Hnf-1β抑制Wnt途径基因的机制。我们将检验hnf-1β形成的假设 抑制染色质环对组蛋白修饰、染色质重塑和 转录延伸。特殊目标2将应用小鼠遗传学来阐明失调的Wnt的作用 Hnf-1β突变表型中的信号转导。我们将确定Wnt途径基因的突变是否 在hnf-1β突变小鼠中过表达可改善肾脏功能和结构。总的来说，拟议的研究 将促进我们对基因调控的理解，揭开hnf-1β突变是如何产生肾脏的 β相关的囊性肾脏疾病的潜在治疗靶点。

ABSTRACT The purpose of this MERIT renewal is to continue our studies on hepatocyte nuclear factor-1β (HNF-1β) and its roles in kidney-specific gene expression and cystic kidney diseases. HNF-1β is a DNA-binding transcription factor that regulates tissue-specific gene expression in the kidney and other epithelial organs. Mutations of HNF- 1β produce congenital anomalies of the kidney and urinary tract, cystic kidney disease, autosomal dominant tubulointerstitial kidney disease, and inherited tubulopathies. To unravel the pathogenesis of these disorders, we have produced HNF-1β mutant mice that develop phenotypes similar to those seen in affected humans. Analysis of the mutant mice has revealed that HNF-1β plays a central role in the expression of polycystic kidney disease genes, such as PKD2 and PKHD1. During the last project period, we used genome-wide ChIP-seq and RNA-seq to identify transcriptional networks that are directly regulated by HNF-1β. Together with new mutant mouse models, these studies uncovered novel roles of HNF-1β in the regulation of Wnt signaling, cAMP signaling, lipid metabolism, urinary concentration, and expression of noncoding RNAs. Preliminary studies using mass spectrometry revealed that HNF-1β interacts with proteins involved in chromatin remodeling, histone modification, and transcription elongation. In the next project period we will extend this work to further unravel the functions of HNF-1β in the kidney. Specific Aim 1 will use biochemical studies to unravel the molecular mechanisms whereby HNF-1β represses Wnt pathway genes. We will test the hypothesis that HNF-1β forms repressive chromatin loops that exert long-range effects on histone modification, chromatin remodeling, and transcription elongation. Specific Aim 2 will apply mouse genetics to elucidate the roles of dysregulated Wnt signaling in the HNF-1β mutant phenotype. We will determine whether mutations of Wnt pathway genes that are overexpressed in HNF-1β mutant mice improve kidney function and structure. Collectively, the proposed studies will advance our understanding of gene regulation, unravel how mutations of HNF-1β produce kidney abnormalities, and identify potential therapeutic targets for HNF-1β-related cystic kidney diseases.