Xenobiotic Transporter Regulation and IRIP Function

异生物质转运蛋白调节和 IRIP 功能

• 批准号: 8534794
• 负责人: Yan Shu
• 金额: $ 30.42万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8534794
• 关键词: Accounting; Adverse drug effect; Affect; Carrier Proteins; Cell Line; Cell model; Cells; Cellular Membrane; Clinical; Data; Dose; Drug Prescriptions; Drug Regulations; Endotoxemia; Endotoxins; Exons; Fatty Liver; Gene Delivery; Gene Targeting; Genes; Genetic Models; Hepatic; Hepatocyte; In Vitro; Ischemia; Kinetics; Knockout Mice; Leptin; Lipopolysaccharides; Liver; Liver diseases; Mediating; Membrane; Metabolic; Metformin; Modeling; Molecular; Mouse Protein; Mouse Strains; Mus; Obese Mice; Obesity; Organic Cation Transporter 1; Outcome; Pathway interactions; Patients; Pharmaceutical Preparations; Pharmacotherapy; Play; Protein Overexpression; Proteins; Regulation; Reperfusion Injury; Reperfusion Therapy; Research; Role; Site; System; Techniques; Testing; Therapeutic; Tissues; Transmembrane Transport; United States; Variant; Wild Type Mouse; Xenobiotics; clinically significant; diabetic; drug efficacy; genetic manipulation; in vivo; liver ischemia; novel; overexpression; prevent; protein expression; protein function; protein transport; response; trafficking; uptake

DESCRIPTION (provided by applicant): Xenobiotic transporters play a critical role in drug disposition and response. Among recognized examples, the organic cation transporter 1 (OCT1) has been demonstrated by us as a key determinant of the therapeutic response to metformin, one of top ten prescription drugs in the United States. Despite their clinical significance, many xenobiotic transporters, particularly those uptake transporters including OCT1, are poorly characterized in their regulation. The recently identified ischemia/reperfusion-inducible protein (IRIP) regulates a variety of transporters in vitro mediating membrane transport of endogenous metabolites and xenobiotics. Therefore, IRIP may represent a novel regulatory mechanism for transporter activity with a substantial effect on clinical drug therapy, and studies are highly warranted to characterize the, as of yet unknown, IRIP function in the body. Our exciting preliminary results indicate that hepatic overexpression of IRIP is associated with a strikingly reduced hepatic accumulation of metformin in the mice administrated with the drug. We also observed altered metformin accumulation and IRIP expression in the livers of obese mice and those received the endotoxin lipopolysaccharide (LPS). Using gene targeting, we have generated a knockin mouse strain that can be used to generate global and conditional IRIP knockout mice. These knockout mice, along with our established cell models and gene delivery techniques, provide a powerful system to test our central hypothesis that IRIP expression affects the disposition and response of clinically important drugs which are substrates of the xenobiotic transporters regulated by IRIP. We propose three specific research aims. In Aim 1, by using genetic manipulation and model compounds in cell models, we will delineate the mechanism of transporter regulation by IRIP at the protein activity, cellular and molecular levels. In Aim 2, we will determine how liver- specific and ubiquitous alteration in IRIP expression affects transporter function and metformin disposition. Hepatic conditional IRIP knockout (mIRIP?hep) mice, hepatic IRIP overexpression (mIRIP+hep), global IRIP knockout (mIRIP-/-), and their corresponding control mice will be employed to perform the studies in Aim 2. In addition, as transporter activities and drug disposition are significantly changed during pathophysiological conditions, in Aim 3 we will use the mouse and in vitro cellular models to define the role of IRIP in regulation of drug disposition during fatty liver disease, lipopolysaccharide-induced endotoxemia and ischemia/ reperfusion injury. The proposed research will characterize the first function of mammalian IRIP in the body. The results will significantly aid in our understanding of xenobiotic transporter regulation and provide a target for improvement of drug efficacy and avoidance of drug side effects for patients.

描述（由申请方提供）：外源性转运蛋白在药物处置和反应中起关键作用。在公认的例子中，我们已经证明有机阳离子转运蛋白1（OCT 1）是二甲双胍治疗反应的关键决定因素，二甲双胍是美国十大处方药之一。尽管它们的临床意义，许多异生物质转运蛋白，特别是那些摄取转运蛋白，包括OCT 1，在其调节的特点很差。缺血/再灌注诱导蛋白（ischemia/reperfusion-inducible protein，IRIP）是近年来发现的一种在体外调控多种转运蛋白介导内源性代谢物和外源性物质的膜转运的蛋白质。因此，IRIP可能代表了一种新的转运蛋白活性的调节机制，对临床药物治疗具有实质性影响，并且非常有必要进行研究来表征IRIP在体内的功能，尽管目前尚不清楚。我们令人兴奋的初步结果表明，肝脏过度表达IRIP与二甲双胍在给药小鼠中的肝脏蓄积显著减少有关。我们还观察到肥胖小鼠和接受内毒素脂多糖（LPS）的小鼠肝脏中二甲双胍蓄积和IRIP表达的改变。使用基因靶向，我们已经产生了敲入小鼠品系，其可用于产生全局和条件性IRIP敲除小鼠。这些基因敲除小鼠，沿着我们建立的细胞模型和基因递送技术，提供了一个强大的系统来测试我们的中心假设，即IRIP表达影响临床重要药物的处置和反应，这些药物是由IRIP调节的异生物质转运蛋白的底物。我们提出了三个具体的研究目标。目的一，通过基因操作和模型化合物在细胞模型中的应用，我们将在蛋白质活性、细胞和分子水平上阐明IRIP调控转运蛋白的机制。 在目标2中，我们将确定肝脏特异性和普遍存在的IRIP表达改变如何影响转运蛋白功能和二甲双胍处置。肝条件性IRIP基因敲除（mIRIP？hep）小鼠、肝IRIP过表达（mIRIP+hep）、整体IRIP敲除（mIRIP-/-）及其相应的对照小鼠将用于进行目的2中的研究。此外，由于转运蛋白活性和药物处置在病理生理条件下发生显著变化，在目标3中，我们将使用小鼠和体外细胞模型来确定IRIP在脂肪肝疾病、脂多糖诱导的内毒素血症和缺血/再灌注损伤期间调节药物处置的作用。拟议的研究将描述哺乳动物IRIP在体内的第一个功能。这一结果将有助于我们更好地理解外源性物质转运蛋白的调控机制，并为提高药物疗效和避免药物副作用提供靶点。