Regulation of drug metabolizing enzymes by miRNAs

miRNA 对药物代谢酶的调节

• 批准号: 9084600
• 负责人: Todd C. Skaar
• 金额: $ 48.42万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 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 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9084600
• 关键词: 3' Untranslated Regions; Address; Adult; Affect; Alleles; Binding Sites; Biological Assay; CYP1A2 gene; CYP2B6 gene; CYP2C19 gene; CYP2C9 gene; CYP2D6 gene; CYP3A4 gene; Cells; Childhood; Clinical; Clinical Trials; Cytochrome P450; Data; Development; Drug Controls; Drug Exposure; Drug Interactions; Drug Kinetics; Drug Regulations; Drug Targeting; Enzymes; Funding; Gene Expression; Gene Targeting; Genes; Genetic Variation; Genotype; Goals; Growth; Health; Hepatic; Hepatocyte; Human; Individual; Lead; Liver; Measures; Metabolism; MicroRNAs; Pathway interactions; Pattern; Pharmaceutical Preparations; Pharmacotherapy; Phase; Phenotype; Plasma; Play; Reaction; Regulation; Regulator Genes; Regulatory Pathway; Rifampin; Role; Safety; Sampling; Seeds; Site; Testing; Untranslated RNA; Untranslated Regions; base; design; drug efficacy; drug metabolism; fetal; genetic variant; genome-wide analysis; improved; liver function; liver metabolism; mRNA Expression; novel; predictive marker; prospective; protein expression; response

DESCRIPTION (provided by applicant): Variable drug disposition is key determinant of drug efficacy and safety. Our long-term goal is to better understand the mechanisms responsible for the interindividual variability in drug disposition and effect, and eventually use this informationto personalize drug therapies. Although some of the variability is attributable to drug interactions and genetic variants, the cause of much of it remains unknown. During the current funding period, we have identified large developmental (fetal to pediatric to adult) changes in hepatic expression of human miRNAs. Many of these are predicted to target drug disposition genes. Some of those miRNAs have substantial interindividual variability in hepatic expression. miRNA expression in hepatocytes was also changed by rifampin, a drug known to alter drug metabolism. We have also shown that miRNAs target pathways that regulate drug metabolism and disposition and that genetic variants in miRNA target genes appear to influence drug metabolism. Following up on these findings, we have also identified additional SNPs in the seed sequences of predicted miRNA binding sites of hepatic regulatory genes that are associated with allele-specific expression. Our central hypothesis is that hepatic miRNAs regulate developmental changes and contribute to the interindividual variability in the expression of key drug metabolizing enzymes, and thereby, alter drug exposure. Our first aim will be to determine the effect of altered miRNA expression on hepatocyte drug metabolism. Primary human hepatocytes will be transfected with miRNA mimics that show developmental changes and substantial interindividual variability in hepatic expression. Hepatocyte responses will be determined by measuring the metabolism probe substrates for specific clinically important cytochrome P450 enzymes and global mRNA expression. Our second aim will test genetic variants in predicted miRNA binding sites of genes that are important for drug disposition. We have developed a novel high throughput bioassay to test large numbers of 3' UTR SNPs in miRNA binding sites to identify those which affect miRNA targeting and gene expression. Our last aim will determine the ability of plasma miRNAs to predict hepatic metabolism by five clinically important cytochrome P450 enzymes. This will be done using plasma samples from 2 completed prospective clinical trials. Those trials were designed to measure the pharmacokinetics of 5 probe drugs that determine the activity of CYP3A4/5, CYP2B6, CYP2C19, CYP2C9, and CYP1A2 enzymes. By completing these studies, we expect to 1) understand the functional impact of the developmental changes in hepatic miRNA expression on drug metabolism, 2) identify functional SNPs in miRNA target sites that alter drug metabolism, and 3) discover plasma miRNA patterns that predict hepatic drug metabolism. This should lead to a better understanding of the role of miRNAs in regulatory mechanisms of the developing liver. Ultimately, we expect that it will improve the prediction of variability in drug metabolism across the developmental continuum.

描述（由申请人提供）：可变的药物处置是药物功效和安全性的关键决定因素。我们的长期目标是更好地了解导致药物配置和效果个体差异的机制，并最终利用这些信息来个性化药物治疗。尽管一些变异可归因于药物相互作用和遗传变异，但其中大部分原因仍不清楚。在当前资助期间，我们已经发现人类 miRNA 肝脏表达的巨大发育变化（从胎儿到儿童再到成人）。其中许多预计以药物处置基因为目标。其中一些 miRNA 的肝脏表达存在显着的个体差异。利福平（一种已知会改变药物代谢的药物）也会改变肝细胞中的 miRNA 表达。我们还表明，miRNA 靶向调节药物代谢和处置的途径，并且 miRNA 靶基因的遗传变异似乎会影响药物代谢。根据这些发现，我们还在肝调控基因的预测 miRNA 结合位点的种子序列中鉴定了与等位基因特异性表达相关的其他 SNP。我们的中心假设是，肝脏 miRNA 调节发育变化，并导致关键药物代谢酶表达的个体差异，从而改变药物暴露。我们的首要目标是确定 miRNA 表达改变对肝细胞药物代谢的影响。原代人肝细胞将用 miRNA 模拟物转染，这些模拟物显示发育变化和肝表达的显着个体间差异。通过测量特定临床重要细胞色素 P450 酶的代谢探针底物和整体 mRNA 表达来确定肝细胞反应。我们的第二个目标是测试对药物处置很重要的基因的预测 miRNA 结合位点的遗传变异。我们开发了一种新型高通量生物测定法来测试 miRNA 结合位点中的大量 3' UTR SNP，以识别那些影响 miRNA 靶向和基因表达的 SNP。我们的最后一个目标是确定血浆 miRNA 通过五种临床上重要的细胞色素 P450 酶预测肝脏代谢的能力。这将使用来自 2 项已完成的前瞻性临床试验的血浆样本来完成。这些试验旨在测量 5 种探针药物的药代动力学，以确定 CYP3A4/5、CYP2B6、CYP2C19、CYP2C9 和 CYP1A2 酶的活性。通过完成这些研究，我们期望 1) 了解肝脏 miRNA 表达的发育变化对药物代谢的功能影响，2) 识别改变药物代谢的 miRNA 靶位点中的功能性 SNP，以及 3) 发现预测肝脏药物代谢的血浆 miRNA 模式。这应该有助于更好地了解 miRNA 在发育中肝脏的调节机制中的作用。最终，我们期望它将改善对整个发育过程中药物代谢变异性的预测。