Regulation of Xenobiotic- and Endobiotic-Metabolizing Enzyme Expression and Function

异源生物/内生代谢酶催化药物、致癌物、环境毒物和内源性化学物质的生物活化和解毒。我研究计划的一个长期目标是了解生化、分子和细胞因素如何调节这些酶及其生物功能，从而促进基础科学的个体差异对化学物质的反应。我的研究计划的重点是一种被称为乙醛氧化酶-1(AOX1)的外源/内生代谢酶，它能代谢氮杂环药物、其他外源生物和具有生理意义的内源性化学物质。它导致了对人类的化学毒性和药物开发的失败。AOX1的表达和催化活性表现出很大的个体差异，但这种生物学现象及其生理功能的潜在机制尚不清楚。AOX1是一种在许多组织中表达的日益重要但相对未知的酶，鉴于对AOX1基础生物学的巨大了解差距，我目前NSERC DG应用的总体目标是揭开调控AOX1基因表达和功能的基本机制，并确定遗传和非遗传因素如何影响AOX1的生物学功能。其具体目的是1)阐明各种核受体转录调控AOX1表达和功能的生化、分子和细胞机制；2)研究自然发生的AOX1基因变异如何影响其表达、化学-酶相互作用和酶功能；以及3)探索microRNAs(表观遗传调节因子)在转录后调控AOX1表达和功能中的作用。方法论。实验方法将包括细胞培养模型中的各种生化、分子生物学和药理学技术。将使用最先进的技术，包括超高效液相色谱-串联质谱仪、定量靶向蛋白质组学、染色质免疫沉淀-测序和基因编辑。冲击力。我的研究计划将发现核受体、遗传/转录变异体、microRNAs、各种外源/内源化学物质以及调控因素之间复杂的相互作用或交叉调控对AOX1调控的新的基本概念。产生的机制信息将1)识别新的生化和分子方法来调节酶的生物功能；2)提供关于为什么个体对某些药物、毒物、其他外源物质和内源性化学物质反应不同的分子和遗传基础的新见解；3)使我们能够预测AOX1介导的化学作用和毒性的个体差异。我的研究项目将为加拿大的生命科学/生物技术/制药部门培养下一代研究科学家。

Xenobiotic/endobiotic-metabolizing enzymes catalyze the bioactivation and detoxification of drugs, carcinogens, environmental toxicants, and endogenous chemicals. A LONG-TERM GOAL of my research program is to understand how biochemical, molecular, and cellular factors regulate these enzymes and their biological functions, thereby advancing the fundamental science underlying individual variations in response to chemicals. A focus of my research program is on a xenobiotic/endobiotic-metabolizing enzyme known as aldehyde oxidase-1 (AOX1), which metabolizes azaheterocyclic drugs, other xenobiotics, and endogenous chemicals of physiological importance. It has contributed to chemical-induced toxicity in humans and failures in drug development. AOX1 expression and catalytic activity show large individual variations, but the underlying mechanisms for this biological phenomenon and its physiological functions are not known. Given the large knowledge gap on the fundamental biology of AOX1, an increasingly important yet relatively uncharacterized enzyme expressed in many tissues, the OVERALL OBJECTIVE of my current NSERC DG application is to unravel the fundamental mechanisms regulating AOX1 gene expression and function, and determine how genetic and non-genetic factors impact AOX1 biological functions. The SPECIFIC AIMS are to 1) elucidate the biochemical, molecular, and cellular mechanisms by which various nuclear receptors transcriptionally regulate AOX1 expression and function; 2) investigate how naturally-occurring AOX1 genetic variants affect its expression, chemical-enzyme interaction, and enzymatic function; and 3) explore the role of microRNAs (epigenetic modulators) in the post-transcriptional regulation of AOX1 expression and function. METHODOLOGY. The experimental approaches will include various biochemical, molecular biology, and pharmacological techniques in cell culture models. State-of-art technologies, including ultra-high-performance liquid chromatography-tandem mass spectrometry, quantitative targeted proteomics, chromatin immunoprecipitation-sequencing, and gene editing, will be used. IMPACT. My research program will discover new fundamental concepts of AOX1 regulation by nuclear receptors, genetic/transcript variants, microRNAs, various exogenous/endogenous chemicals, and the complex interplay or cross-regulation among the regulatory factors. The mechanistic information generated will 1) identify novel biochemical and molecular approaches to modulate the biological function of an enzyme; 2) provide novel insights into the molecular and genetic basis on why individuals respond differently to certain drugs, toxicants, other xenobiotics, and endogenous chemicals; and 3) allow us to predict individual variations in AOX1-mediated chemical action and toxicity. My research program will train the next generation of research scientists for the life sciences/biotechnology/pharmaceutical sectors in Canada.