Regulation of kidney-Specific Gene Expression

本项目的总体目标是了解肝细胞核因子-13（HNF-1（3））在肝细胞凋亡中的作用。 肾特异性基因表达、肾细胞分化和肾器官发生。HNF-1（3属于 一个含有同源结构域的转录因子家族，调节组织特异性基因表达， 肾脏、肝脏、胰腺和其他器官。携带HNF-13突变的人发生成熟发作 年轻5型糖尿病（MODY 5）和先天性肾脏囊性异常。转基因小鼠 在肾特异性启动子的控制下表达突变型HNF-13， 失败，这与MODY 5人类的表型相似。类似地，肾特异性HNF-κ B缺失 1（3）使用Cre/loxP重组导致肾囊肿形成。HNF-1 β 3突变小鼠表现出降低的 Pkhdl的表达，该基因在常染色体隐性遗传性多囊肾病（ARPKD）中突变，和 HNF-13直接调节Pkhdl启动子。这些研究将Pkhdl鉴定为HNF的新基因靶点， 肾脏中了13枪他们建立了一个以前未被认识的两个肾囊肿疾病之间的联系，MODY 5 和ARPKD，并表明MODY 5人类囊肿形成的机制涉及下- PKHD 1基因表达的调控。为了验证这一假设并进一步确定HNF-13的功能， 在肾脏方面，我们将完成以下具体目标： 1.明确辅激活因子和组蛋白乙酰化在Pkhdl基因转录调控中的作用。 2.确定SUMO连接酶和泛素连接酶如何间接调节HNF-13的活性。 3.确定HNF-13如何调节肾脏和肝脏中Pkhdl的组织特异性表达。 4.阐明肾和泌尿生殖道异常的分子发病机制， HNF-13突变。 拟议的研究将利用基因修饰小鼠来定义体内表达模式， 疾病表型和生物化学研究，以阐明分子机制。了解 HNF-13的功能和Pkhdl基因转录的调节将为研究HNF-13的功能提供新的思路。 先天性肾脏异常和ARPKD的发病机制，ARPKD是最常见的遗传病之一， 肾功能衰竭的病因有哪些

The overall goal of this project is to understand the roles of hepatocyte nuclear factor-13 (HNF-1(3)in kidney-specific gene expression, renal cell differentiation, and kidney organogenesis. HNF-1(3belongs to a family of homeodomain-containing transcription factors that regulate tissue-specific gene expression in the kidney, liver, pancreas, and other organs. Humans with mutations of HNF-13 develop maturity-onset diabetes of the young type 5 (MODY5) and congenital cystic abnormalities of the kidney. Transgenic mice expressing mutant HNF-13 under the control of a kidney-specific promoter develop kidney cysts and renal failure, which is similar to the phenotype of humans with MODY5. Similarly, kidney-specific deletion of HNF- 1(3 using Cre/loxP recombination results in renal cyst formation. HNF-1{3mutant mice show decreased expression of Pkhdl, the gene mutated in autosomal recessive polycystic kidney disease (ARPKD), and HNF-13 directly regulates the Pkhdl promoter. These studies identify Pkhdl as a novel gene target of HNF- 13 in the kidney. They establish a previously unrecognized link between two renal cystic diseases, MODY5 and ARPKD, and suggest that the mechanism of cyst formation in humans with MODY5 involves down- regulation of PKHD1 gene expression. To test this hypothesis and to further define the functions of HNF-13 in the kidney, we will complete the following specific aims: 1. Define the roles of coactivators and histone acetylation in the regulation of Pkhdl gene transcription. 2. Determine how the activity of HNF-13 is reciprocally regulated by SUMO ligases and ubiquitin ligases. 3. Determine how HNF-13 regulates the tissue-specific expression of Pkhdl in the kidney and liver. 4. Elucidate the molecular pathogenesis of the kidney and genitourinary tract abnormalities caused by mutations of HNF-13. The proposed studies will utilize genetically-modified mice to define in vivo expression patterns and disease phenotypes and biochemical studies to elucidate molecular mechanisms. Understanding the functions of HNF-13 and the regulation of Pkhdl gene transcription will provide insights into the pathogenesis of congenital kidney abnormalities and ARPKD,which is one of the most common genetic causes of renal failure in infants and children.