Screening for LXR agonists-inhibitors of brain amyloidosis and inflammation

筛选 LXR 激动剂 - 脑淀粉样变性和炎症抑制剂

• 批准号: 7449780
• 负责人: ILIYA LEFTEROV
• 金额: $ 22.42万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-15 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7449780
• 关键词: Academia; Accounting; Active Sites; Address; Affect; Agonist; Alzheimer' s Disease; Amyloid; Amyloid deposition; Amyloidosis; Apolipoprotein E; Astrocytes; Behavioral; Biological Assay; Biological Models; Brain; Cell Line; Cells; Chemicals; Cholesterol; Cholesterol Homeostasis; Classification; Clinical; Clinical Research; Clinical Trials; Complex; Data; Deposition; Development; Disease; Disease model; Drug Industry; Endopeptidases; Evaluation; Fatty Acids; Gene Expression; Generations; Genes; Genetic Transcription; Goals; Impaired cognition; In Vitro; Industry; Inflammation; Inflammatory; Knock-out; Laboratories; Lead; Ligands; Link; Lipoproteins; Liver; Mediating; Membrane; Messenger RNA; Metabolic Pathway; Microglia; Molecular; Mus; Nerve Degeneration; Neurons; Nuclear; Numbers; Outcome; Pathogenesis; Pathway interactions; Patients; Peptide Hydrolases; Pharmaceutical Preparations; Phospholipids; Physiological; Preclinical Drug Evaluation; Process; Production; Proteolytic Processing; Public Health; Reaction; Reporter; Screening procedure; Testing; Therapeutic; Transgenic Mice; Triglycerides; Up-Regulation; Vaccination; activating transcription factor; amyloid formation; base; cholesterol transporters; cytokine; design; disease phenotype; drug discovery; extracellular; in vivo; in vivo Model; inhibitor/antagonist; neuronal survival; novel therapeutics; prevent; receptor; response; secretase; small molecule; transcription factor; Academia; Accounting; Active Sites; Address; Affect; Agonist; Alzheimer' s Disease; Amyloid; Amyloid deposition; Amyloidosis; Apolipoprotein E; Astrocytes; Behavioral; Biological Assay; Biological Models; Brain; Cell Line; Cells; Chemicals; Cholesterol; Cholesterol Homeostasis; Classification; Clinical; Clinical Research; Clinical Trials; Complex; Data; Deposition; Development; Disease; Disease model; Drug Industry; Endopeptidases; Evaluation; Fatty Acids; Gene Expression; Generations; Genes; Genetic Transcription; Goals; Impaired cognition; In Vitro; Industry; Inflammation; Inflammatory; Knock-out; Laboratories; Lead; Ligands; Link; Lipoproteins; Liver; Mediating; Membrane; Messenger RNA; Metabolic Pathway; Microglia; Molecular; Mus; Nerve Degeneration; Neurons; Nuclear; Numbers; Outcome; Pathogenesis; Pathway interactions; Patients; Peptide Hydrolases; Pharmaceutical Preparations; Phospholipids; Physiological; Preclinical Drug Evaluation; Process; Production; Proteolytic Processing; Public Health; Reaction; Reporter; Screening procedure; Testing; Therapeutic; Transgenic Mice; Triglycerides; Up-Regulation; Vaccination; activating transcription factor; amyloid formation; base; cholesterol transporters; cytokine; design; disease phenotype; drug discovery; extracellular; in vivo; in vivo Model; inhibitor/antagonist; neuronal survival; novel therapeutics; prevent; receptor; response; secretase; small molecule; transcription factor

DESCRIPTION (provided by applicant): Despite the enormous efforts in academia and in pharmaceutical industry, Ab vaccination, y- and b-secretase inhibitors are still far from clinical use. Drugs that ameliorate AD phenotypes by interfering cholesterol metabolism have been also suggested, but the rationale for using those is poorly defined and in all of the cases the molecular mechanisms which account for their beneficial effects are poorly understood. Therefore there remains a great need for other strategies of lowering Ab. Nuclear Liver X receptors (LXRa and LXRb) are transcription factors that control the expression of genes involved in cholesterol metabolism. We have found that activated LXR regulate metabolic pathways of brain cholesterol intra- and extracellular transport that influence APP processing, b-amyloid deposition and its clearance from brain. Moreover, we and others have shown, that treatments of neuronal cell lines and primary neurons with natural or synthetic LXR ligands decrease Ab secretion, and that in vivo treatment of young AD model mice with a synthetic LXR ligand, increased the expression of LXR responsive genes in CNS and decreased soluble b-amyloid levels in their brains. We have also found that the application of LXR ligands inhibited secretion of inflammatory cytokines and increased neuronal survival following Ab or LPS treatment. The ultimate beneficial outcome of LXR ligand treatment on AD phenotype in vivo is a combination of effects mediated by genes expressed in neurons and astrocytes influencing Ab generation, b-amyloid formation and clearance, and by genes expressed in microglia which are tightly related to both - Ab clearance and inflammation. The data therefore substantiate the design of a drug discovery study for identification of LXR activators/agonists and their systematic evaluation in well established in vitro and in vivo model systems. In Specific aim 1, the activated status of LXR will be evaluated by their ability to increase dramatically the transcription of ABCA1 - a major LXR response gene. Thus, the increased amount of ABCA1 mRNA following in vitro application of a given compound (altogether >50,000 for screening) will serve as a reporter for LXR activation. Compounds that meet the criteria for LXR activation will be further screened for their ability to reduce Ab production in vitro. "Hits" with dual stimulatory effect on ABCA1 expression and apoE secretion, ability to reduce Ab and to facilitate cholesterol efflux will be further characterized in LXR knockout cell based assays. In addition, potent compounds will be characterized for their inhibitory effects on cytokine expression and regulatory effects on transcriptional activity of genes with undesired effects on fatty acids and triglyceride synthesis. In Specific Aim 2, the two most potent compounds will be chosen for initial in vivo tests in PS1APP transgenic mice. PUBLIC HEALTH RELEVANCE: Despite the enormous efforts in academia and in pharmaceutical industry, drugs based on the recent progress in our understanding for Alzheimer disease are still not available for clinical use. Brain cholesterol metabolism and its relation to different aspects of the disease pathogenesis substantiates the development of new therapeutic approaches based on complex regulatory networks controlled by transcription factors and their responsive genes. We are proposing a drug screening approach for identification of natural or synthetic compounds that activate transcription factors called Nuclear Liver X receptors (LXRa and LXRb) and therefore lead to upregulation and increased expression of genes involved in cholesterol metabolism. This drug discovery study is based on data generated in our and other laboratories which confirm that LXR controlled cholesterol transporters and lipoproteins in brain are involved in b-amyloid aggregation, deposition and clearance. Therefore, LXR activators can be used for lowering Ab inhibition of inflammation and improvement of behavioral deficits.

描述（由申请人提供）：尽管在学术界和制药行业做出了巨大努力，但AB疫苗，Y和B-分泌酶抑制剂仍远离临床使用。还提出了通过干扰胆固醇代谢来改善AD表型的药物，但是使用这些表型的药物的定义很差，并且在所有情况下，造成其有益作用的分子机制均被理解不足。因此，仍然需要其他降低AB的策略。核肝X受体（LXRA和LXRB）是控制胆固醇代谢的基因表达的转录因子。我们发现活化的LXR调节脑胆固醇内和细胞外转运的代谢途径，这些胆固醇会影响应用程序加工，B-淀粉样蛋白沉积及其从大脑的清除率。 Moreover, we and others have shown, that treatments of neuronal cell lines and primary neurons with natural or synthetic LXR ligands decrease Ab secretion, and that in vivo treatment of young AD model mice with a synthetic LXR ligand, increased the expression of LXR responsive genes in CNS and decreased soluble b-amyloid levels in their brains.我们还发现，LXR配体的应用抑制了炎症细胞因子的分泌，AB或LPS治疗后神经元存活增加。 LXR配体处理对体内AD表型的最终有益结果是由在神经元和星形胶质细胞中表达的基因介导的作用的组合，影响AB的产生，B-淀粉样蛋白的形成和清除率，以及在小胶质细胞中表达的基因，这些基因与与AB ABS的相关 - AB AB CELAMBANCE和WELAMMATION和ABS炎症。因此，数据证实了一项药物发现研究的设计，用于鉴定LXR激活剂/激动剂及其在体外和体内模型系统良好的系统评估中。在特定的目标1中，LXR的活化状态将通过其显着增加ABCA1转录的能力来评估。因此，在体外应用给定化合物（完全> 50,000次筛查）后，ABCA1 mRNA的量增加将作为LXR激活的记者。符合LXR激活标准的化合物将进一步筛选其在体外减少AB产生的能力。 “命中”具有对ABCA1表达和APOE分泌的双重刺激作用，减少AB和促进胆固醇外排的能力将在基于LXR基因敲除细胞测定中进一步表征。此外，有效化合物的抑制作用对细胞因子表达的抑制作用以及对基因转录活性的抑制作用以及对脂肪酸和甘油三酸酯合成的影响的调节作用。在特定的目标2中，将在PS1APP转基因小鼠中选择两种最有效的化合物进行初始体内测试。公共卫生相关性：尽管学术界和制药行业做出了巨大的努力，但基于我们对阿尔茨海默氏病的理解的最新进展，仍无法供临床使用。脑胆固醇代谢及其与疾病发病机理不同方面的关系证明了基于转录因子控制的复杂调节网络及其反应性基因的复杂调节网络的发展。我们提出了一种鉴定自然或合成化合物的药物筛查方法，该方法激活了称为核肝X受体（LXRA和LXRB）的转录因子，因此导致了参与胆固醇代谢的基因的上调并增加了基因的表达。这项药物发现研究基于我们和其他实验室中产生的数据，这些数据证实了LXR控制的胆固醇转运蛋白和脑中脂蛋白参与B-淀粉样蛋白聚集，沉积和清除率。因此，LXR激活剂可用于降低AB抑制炎症和行为缺陷的改善。