Epigenetic Regulation of Kidney Development

描述（由申请人提供）：完全分化的细胞由其表达的基因以及最终的生理功能定义。这种基因表达或转录组的正常模式在患病状态下会发生改变，从而导致功能受到干扰、生长失调以及与其他细胞的通讯受到影响。问题是，在没有基因突变的情况下，这些异常表达模式是如何建立和维持的？我们认为基因组的表观遗传修饰，特别是组蛋白甲基化，会影响患病组织中的基因表达变化。为了探索这个假设，我们必须首先了解在胚胎发育过程中，随着细胞谱系的决定，表观遗传修饰是如何被印记的。此前，PI 已将 Pax2 确定为肾上皮谱系中的关键 DNA 结合蛋白。随后，该实验室发现 PTIP 作为一种衔接蛋白，可将 Pax2 与组蛋白甲基化复合物连接起来，从而在目标基因上留下积极的表观遗传标记。在此应用中，Aim 1 将使用染色质免疫沉淀、下一代测序和转基因小鼠的特定品系来绘制 Pax2/PTIP 与基因组相互作用的位点，并将其与基因表达模式相关联。此外，我们有第一个真实的证据表明以细胞特异性方式改变组蛋白甲基化途径可以导致慢性肾脏疾病。在目标 2 中，我们将定义 PTIP 和组蛋白甲基化在肾间质纤维化中的作用，并将其与已知介导纤维化的 TGF-b 信号通路相关联。虽然癌症和其他疾病状态的表观遗传变化存在许多相关性，但我们的研究将首次解决表观遗传修饰是否可以在没有其他突变或环境侵害的情况下直接引发疾病状态。我们的初步数据强烈表明他们可以。 公众健康相关性：慢性和急性肾脏疾病日益影响公众健康，但肾脏疾病的起源和治疗尚不清楚。该应用解决了肾细胞生理学的遗传和表观遗传基础、肾细胞如何在发育中的胚胎中形成以及肾细胞如何在成年生活中维持其正常功能。我们发现了新的基因和途径，它们对肾脏的正常发育产生严重影响，并导致多种肾脏疾病的发生和进展。该应用程序将深入探索这些途径，为新的干预途径提供机制见解。

DESCRIPTION (provided by applicant): A fully differentiated cell is defined by the genes it expresses and, ultimately, by its physiological functions. This normal pattern of gene expression, or transcriptome, is altered in a diseased state such that function is perturbed, growth is deregulated, and communication with other cells affected. The question is, how are these abnormal expression patterns established and maintained in the absence of genetic mutations? We propose that epigenetic modifications on the genome, and specifically histone methylation, impact gene expression changes in diseased tissues. To explore this hypothesis, we must first understand how epigenetic modifications are imprinted during development of the embryo, as cell lineages decisions are made. Previously, the PI has identified Pax2 as a critical DNA binding protein in the renal epithelial lineage. The lab then discovered PTIP as an adaptor protein that links Pax2 to a histone methylation complex to imprint positive epigenetic marks on target genes. In this application, Aim 1 will use chromatin immunoprecipitation, next generation sequencing, and specific strains of genetically altered mice to map the sites of Pax2/PTIP interactions with the genome and to correlate this with gene expression patterns. Furthermore, we have the first real evidence that altering a histone methylation pathway in a cell specific manner can lead to chronic renal disease. In Aim 2, we will define the role of PTIP and histone methylation in renal interstitial fibrosis and correlate this with TGF-b signaling pathways that are known to mediate fibrosis. While there are many correlations of epigenetic changes in cancer and other disease states, our studies will address for the first time whether epigenetic modifications can directly initiate a disease state in the absence of other mutations or environmental insults. Our preliminary data strongly suggests that they can. PUBLIC HEALTH RELEVANCE: Chronic and acute kidney disease increasingly impacts public health, yet the origin and treatment of renal diseases are not well understood. This application addresses the genetic and epigenetic basis of kidney cell physiology, how kidney cells are formed in the developing embryo, and how kidney cells maintain their normal functions in adult life. We have discovered new genes and pathways that critically impact normal development of the kidney and contribute to the initiation and progression of a variety of kidney diseases. This application will explore these pathways in depth to provide mechanistic insights for new avenues of intervention.