FUNCTION OF HEPATOCYTE-ENRICHED TRANSCRIPTION FACTORS

肝细胞富集转录因子的功能

• 批准号: 6289121
• 负责人: FRANK GONZALEZ
• 金额: --
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6289121
• 关键词: animal genetic material tag; chemical carcinogen; cytochrome P450; developmental genetics; enhancer binding protein; enzyme activity; enzyme induction /repression; gene expression; genetic promoter element; genetically modified animals; laboratory mouse; laboratory rat; liver cells; toxin metabolism

Xenobiotic-metabolizing enzymes are responsible for metabolism and inactivation of all clinically used drugs. They are also involved in the metabolic activation or inactivation of toxins, mutagens and chemical carcinogens. Marked differences in levels of expression of these enzymes have been found in humans and these differences could contribute to interindividual differences in sensitivities to drugs and carcinogens. Variable gene expression could account for some differences in levels of expression of xenobiotic-metabolizing enzymes. Most of these enzymes are expressed in the liver and their genes are under control of different hepatocyte transcription factors. Several families of transcription factors are preferentially expressed in the liver and control liver-specific gene expression. Typically, in vitro techniques, including transfections of reporter gene constructs and DNA binding assays, are used to study gene regulation. However, it is difficult to directly demonstrate that results obtained using in vitro studies actually reflect gene expression in the intact animal. Studies to determine whether hepatocyte-enriched factors are involved in regulating gene expression in vivo can be done by using gene knockouts to disrupt expression of transcription factors and then determine the effects transcription factor loss on target gene expression. To investigate the role of liver-enriched transcription factors in control of P450 gene expression and expression of other genes involved in liver function, null mice are being produced. Conditional gene disruption is required since strait embryonic disruption of transcription facto genes frequently results in embryonic lethality or early neonatal death. Conditional-null mice produced using the Cre-LoxP method were developed for the transcription factors HNF-1alpha and C/EBPalpha. Phenotypes were observed and gene expression patterns determined using Northern blot and Western blot analyses. The data indicate that mice lacking expression of these transcription factors develop severe phenotypes including diabetes, dwarfism and hyperbilirubinemia. - Cre recombinase, LoxP site, Cytochromes P, 0, Conditional gene knockout, Hepatocyte, Transcription Factors, Nuclear receptors,

异种生物 - 代谢酶负责代谢和所有临床使用药物的失活。它们还参与了毒素，诱变剂和化学致癌物的代谢激活或失活。在人类中已经发现了这些酶表达水平的显着差异，这些差异可能导致对药物和致癌物敏感性的个体差异。可变基因表达可以解释异种生物生物代谢酶表达水平的某些差异。这些酶中的大多数在肝脏中表达，其基因受到不同肝细胞转录因子的控制。几个转录因子的家族在肝脏中优先表达，并控制肝特异性基因表达。通常，体外技术，包括报告基因构建体和DNA结合测定法的转染，用于研究基因调节。但是，很难直接证明使用体外研究获得的结果实际上反映了完整动物中的基因表达。可以通过使用基因敲除破坏转录因子的表达，然后确定效应转录因子丧失对靶基因表达的影响，可以确定肝细胞增强因子参与调节体内基因表达的研究。为了研究富含肝脏的转录因子在控制肝功能的其他基因的P450基因表达和表达中的作用，正在产生NULL小鼠。由于转录事实基因的海峡胚胎破坏经常导致胚胎致死性或新生儿死亡，因此需要有条件的基因破坏。使用Cre-loxp方法生成的条件无效小鼠是针对转录因子HNF-1Alpha和C/Ebpalpha的。观察到表型，并使用北印迹和蛋白质印迹分析确定基因表达模式。数据表明，缺乏这些转录因子表达的小鼠会发展出严重的表型，包括糖尿病，矮人和高胆红素血症。 - CRE重组酶，LOXP位点，细胞色素P，0，条件基因敲除，肝细胞，转录因子，核受体，