Cytochrome P4501B1 and basal liver PPARa activity

细胞色素 P4501B1 和基础肝脏 PPARa 活性

基本信息

批准号：
8296906
负责人：
COLIN ROBERT JEFCOATE
金额：
$ 32.38万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-04-01 至 2017-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8296906
关键词：
ADD-1 protein Address Adhesions Adipocytes Adipose tissue Adult Affect Agonist Alleles Amino Acids Binding Biological Factors Blood capillaries Breeding CYP1B1 gene Carbohydrates Cells Clinical Research Complex Cytochrome P450 Data Development Developmental Process Diabetes Mellitus Diet Dietary Fats Discontinuous Capillary Effectiveness Embryo Embryonic Development Endothelial Cells Endothelium Event Exhibits FGF21 gene Fat-Restricted Diet Fatty Acids Fatty Liver Fatty acid glycerol esters Fetal Liver Fetus Fibroblasts Gene Cluster Gene Expression Generations Genes Glaucoma Glycogen Goals Hepatic Hepatocyte Human In Vitro Infiltration Intervention Lead Ligands Link Liver Liver neoplasms Mass Spectrum Analysis Measures Mediating Metabolism Mitochondria Morphogenesis Mus Non-Insulin-Dependent Diabetes Mellitus Obesity Oxidative Stress Pathway interactions Peripheral Peroxisome Proliferator-Activated Receptors Regulation Research Role Serum Serum Markers Signal Transduction Site Source Stromal Cells Tamoxifen Testing Therapeutic Time Tissues Variant Weaning adenoma angiogenesis base capillary cell type cytokine endonuclease fatty acid metabolism fatty acid oxidation feeding flavanoid hormone regulation imprint improved in utero in vivo inhibitor/antagonist insulin sensitivity lipid biosynthesis liquid chromatography mass spectrometry liver metabolism macrophage metabolomics non-alcoholic oxidation promoter response stellate cell

项目摘要

DESCRIPTION (provided by applicant): Cytochrome P450 1b1 (Cyp1b1) participates in embryogenesis and is expressed in endothelia, fibroblasts and adipocytes. Genes involved in liver fatty acid metabolism are remarkably affected by deletion of Cyp1b1 in mice, despite only minimal expression in hepatocytes. Two gene clusters, distinguished by responses to dietary fat, are both suppressed by Cyp1b1 deletion and regulated by PPAR? Preliminary data that indicates that Cyp1b1 participates in the generation of endogenous PPAR? ligands will be explored further. Cyp1b1 deletion also suppresses diet-induced obesity and non-alcoholic hepatic steatosis. The increased liver fatty acid metabolism may be associated with decreased oxidative stress, as indicated by improved insulin sensitivity. Cyp1b1 may, therefore, be an unexpected contributor to Type 2 diabetes. Many dietary flavanoids are potent inhibitors of Cyp1b1. Select Cyp1b1 inhibitors, including natural compounds, may have therapeutic value for diabetes. Human Cyp1b1 suppression also enhances liver adenomas, consistent with a role in developmental processes. The proposed research compares the liver gene expression, metabolism responses and adiposity changes in WT and Cyp1b1-ko mice administered low fat/high carbohydrate or high fat/low carbohydrate diets. The goal is to determine how hepatocytes can be indirectly affected by Cyp1b1 metabolism in other cell types, particularly the endothelia of liver sinusoids and adipose tissue. The expression of Cyp1b1 in non-parenchymal liver cells and in fetal liver will be characterized. In order to define the site and timing of Cypb1 intervention, we have introduced a Floxed Cyp1b1 allele into mice. This will ultimately provide the means for controlled Cyp1b1 deletions in mice. We will use this defining set of liver and adipose responses to determine the effectiveness of Cyp1b1 deletions specifically targeted to endothelia by Tie2-Cre. We have shown that Cyp1b1 deletion affects the functions of endothelial cells and suppresses angiogenesis in vivo. Cyp1b1 deletion may cause these adult changes through active participation of Cyp1b1 in the fetal liver development that imprints adult liver regulation. Cre-targeting of Floxed Cyp1b1 will be activated through a tamoxifen-dependent promoter at selected times during development, in order to test whether this early expression contributes to the general deletion effects. Metabolomic studies using 2D-NMR and mass spectrometry analyses on, respectively, liver and serum extracts will focus on establishing that Cyp1b1 deletion increases mitochondrial fatty acid oxidation and glycogen synthesis, while lowering oxidative stress. The roles of PPAR? and PPAR? loss in these liver gene changes of Cyp1b1-ko mice will be tested by comparisons to effects of deleting these PPAR genes in mouse liver. Serum markers applicable to clinical studies will be used in probing these liver changes. PUBLIC HEALTH RELEVANCE: Loss of Cytochrome P450 1B1 (CYP1B1) in humans is linked to Glaucoma and Liver tumors. CYP1B1 variants are common in humans. We find that CYP1B1 losses can counter obesity and improve insulin sensitivity. These studies address how CYP1B1 deletion remarkably increases liver fat oxidation and glycogen synthesis through suppression of PPAR?activity. The pathway offers therapeutic possibilities, including through dietary compounds that bind to CYP1B1.

描述（由申请人提供）：细胞色素P450 1B1（CYP1B1）参与胚胎发生，并在内皮，成纤维细胞和脂肪细胞中表达。尽管仅在肝细胞中表达最小的表达，但与小鼠中CYP1B1的缺失显着影响了参与肝脂肪酸代谢的基因。两个基因簇以对饮食脂肪的反应而区别，都被CYP1B1缺失抑制并受PPAR的调节吗？表明CYP1B1参与内源性PPAR的初步数据？配体将进一步探索。 CYP1B1缺失还抑制了饮食诱导的肥胖症和非酒精性肝脂肪变性。肝脏脂肪酸代谢增加可能与氧化应激降低有关，如胰岛素敏感性的提高所表明。因此，CYP1B1可能是2型糖尿病的意外贡献者。许多饮食类黄酮是CYP1B1的有效抑制剂。精选的CYP1B1抑制剂（包括天然化合物）可能对糖尿病具有治疗价值。人CYP1B1抑制也增强了肝腺瘤，与在发育过程中的作用一致。拟议的研究比较了肝脏基因表达，代谢反应和肥胖度变化，而CYP1B1-KO小鼠施用了低脂肪/高碳水化合物或高脂肪/低脂肪/低碳水化合物饮食。目的是确定如何在其他细胞类型的CYP1B1代谢中间接影响肝细胞，尤其是肝弦和脂肪组织的内皮。将表征CYP1B1在非核肝细胞和胎儿肝脏中的表达。为了定义CYPB1干预的位点和时间，我们将Floxed CYP1B1等位基因引入了小鼠。这最终将提供小鼠控制的CYP1B1缺失的手段。我们将使用这组定义的肝脏和脂肪反应来确定由TIE2-CRE专门针对内皮的CYP1B1缺失的有效性。我们已经表明，CYP1B1缺失会影响内皮细胞的功能并抑制体内血管生成。 CYP1B1缺失可能会通过CYP1B1在胎儿肝发育中积极参与刻有成人肝脏调节的胎儿发育而导致这些成人变化。 Floxed CYP1B1的CRE靶向将通过在发育过程中选定时间的他莫昔芬依赖性启动子激活，以测试这种早期表达是否有助于一般的缺失效应。使用2D-NMR和质谱分析的代谢组学研究分别对肝脏和血清提取物进行分析将集中于确定CYP1B1缺失会增加线粒体脂肪酸氧化和糖原合成，同时降低氧化应激。 PPAR的角色？和PPAR？ CYP1B1-KO小鼠的这些肝基因变化的损失将通过与删除这些PPAR基因在小鼠肝脏中的影响进行测试。适用于临床研究的血清标记将用于探测这些肝脏的变化。公共卫生相关性：人类中细胞色素P450 1B1（CYP1B1）的丧失与青光眼和肝肿瘤有关。 CYP1B1变体在人类中很常见。我们发现CYP1B1损失可以抵抗肥胖并提高胰岛素敏感性。这些研究介绍了CYP1B1如何通过抑制PPAR？活性来显着增加肝脏脂肪氧化和糖原合成。该途径提供了治疗可能性，包括通过与CYP1B1结合的饮食化合物。