Modifications of L-FABP by Reactive Aldehydes in a Model of Chronic ALD

慢性 ALD 模型中活性醛对 L-FABP 的修饰

• 批准号: 7806920
• 负责人: Rebecca LeAnne Smathers McCullough
• 金额: $ 3.16万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2012-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7806920
• 关键词: 4 hydroxynonenal; 4-oxo-2-nonenal; Address; Alcoholic Fatty Liver; Alcoholic Liver Diseases; Alcohols; Aldehydes; Binding; Binding Proteins; Biological Assay; CYP2E1 gene; Cell Nucleus; Cell Respiration; Cells; Chronic; Complex; DNA; Data; Disease; Ethanol; Exposure to; Fatty Acid-Binding Protein 1; Fatty Acids; Free Radicals; Genes; Genetic Transcription; Hepatic; Hepatocyte; Histology; Homeostasis; Hydrogen Peroxide; Immunoblotting; Immunohistochemistry; In Situ; In Vitro; Inflammatory; Injury; Iron; Knock-out; Ligands; Link; Lipid Binding; Lipid Peroxidation; Lipid Peroxides; Lipids; Liver; Liver diseases; MALDI-TOF Mass Spectrometry; Malignant Neoplasms; Mass Spectrum Analysis; Measures; Metabolism; Modeling; Modification; Molecular Chaperones; Monitor; Mus; Nonesterified Fatty Acids; Oxidation-Reduction; Oxidative Stress; PPAR alpha; Pathogenesis; Pathway interactions; Phase; Physiological; Play; Post-Translational Protein Processing; Production; Protein Binding; Protein Denaturation; Proteins; Research; Reverse Transcriptase Polymerase Chain Reaction; Role; Side; Simulate; Site; Site-Directed Mutagenesis; Staging; Survival Rate; System; Techniques; Testing; Time; Toxic effect; Transgenic Organisms; Triglycerides; Western Blotting; Work; chronic alcohol ingestion; covalent bond; design; dinitrophenylhydrazine; feeding; human FABP4 protein; indexing; insight; interest; lipid metabolism; lipid transport; oxidation; peroxidation; research study; response; stable isotope; trafficking; transcription factor; uptake

DESCRIPTION (provided by applicant): Early stages of Alcoholic Liver Disease (ALD) are characterized by the accumulation of lipid within hepatocytes and is collectively referred to as steatosis. It is known that alterations in lipid homeostasis occur in chronic ethanol conditions, and lipid binding proteins that are known to aid in the uptake and trafficking of these lipids have not been investigated. The experiments proposed are designed to test the hypothesis that chronic ethanol consumption leads to the covalent modification of liver fatty acid binding protein (L-FABP) by 4-HNE and 4-ONE, which ultimately leads to the disruption of lipid metabolism and pathogenesis of steatosis in ALD. The first phase of the research plan addresses if L-FABP is covalently modified by 4-HNE and 4-ONE, and what are the physiological and structural consequences ofthis modification. Using in vitro incubation assays, immunoblotting, and-LC-MS/MS and MALDI-TOF-TOF mass spectrometry, covalently modified protein side-chains will be identified. Activity assays will also be conducted to assess the physiological consequences of these modifications on lipid binding. In addition, protein bound lipid will be investigated in the formation of lipid hydroperoxides in an in situ model of oxidative stress. The second phase of the research involves the use of chronic ethanol feeding models in genetically modified stocks of mice, where L-FABP knockout and L-FABP transgenic stocks will be used. Using standard indices of liver injury (ALT, triglyceride content, GSH:GSSG ratios, CYP2E1 activity, and histology), the model will elucidate if L-FABP attributes to the accumulation of lipid in the liver during early phases of ALD. Also, pathways in lipid uptake and trafficking will be evaluated to characterize the model by utilizing techniques involving RT-PCR, immunoblotting, and immunohistochemistry. The data provided by this application will provide further insight into the mechanisms involving 4-HNE and 4-ONE toxicity, and the effects they have on lipid homeostasis in early ALD.

描述(由申请人提供)：酒精性肝病(ALD)的早期特征是肝细胞内脂肪堆积，统称为脂肪变性。众所周知，在慢性乙醇条件下，脂质稳态发生变化，而已知有助于这些脂类摄取和运输的脂结合蛋白尚未被研究。本实验旨在验证慢性酒精摄入导致肝脏脂肪酸结合蛋白(L-FABP)被4-HNE和4-酮共价修饰，最终导致脂肪代谢紊乱和脂肪变性的发病机制。研究计划的第一阶段涉及L-FABP是否被4-HNE和4-酮共价修饰，以及这种修饰的生理和结构后果是什么。利用体外孵育分析、免疫印迹、LC-MS/MS和MALDI-TOF-TOF质谱仪，可以鉴定共价修饰的蛋白质侧链。还将进行活性分析，以评估这些修饰对脂质结合的生理影响。此外，还将在氧化应激的原位模型中研究蛋白质结合的脂质在脂质氢过氧化形成中的作用。第二阶段的研究涉及在转基因小鼠种群中使用慢性乙醇喂养模型，其中将使用L-FABP基因敲除和L-FABP转基因种群。使用肝损伤的标准指标(ALT、甘油三酯含量、谷胱甘肽/谷胱甘肽比值、细胞色素P450-2E1酶活性和组织学)，该模型将阐明L-FABP是否与ALD早期肝脏中脂质的积累有关。此外，还将利用RT-PCR、免疫印迹和免疫组织化学等技术对脂质摄取和转运的途径进行评估，以确定该模型的特征。本申请提供的数据将进一步深入了解4-HNE和4-酮毒性的机制，以及它们对ALD早期脂质平衡的影响。