Trafficking and Regulation of Drug/Xenobiotic Transporter OAT

描述(申请人提供)：有机阴离子转运体(OAT)家族调节多种环境毒素和临床重要药物的吸收、分配和排泄，包括抗HIV治疗药物、抗肿瘤药物、抗生素、抗高血压药物和抗炎药物，因此对哺乳动物物种的生存至关重要。已鉴定出6种燕麦(OAT1、OAT2、OAT3、OAT4、OAT5和OAT6)，并在肾脏、肝脏、脑和胎盘中检测到它们的表达。燕麦在这些器官中的功能障碍极大地导致了肾、肝、神经和胎儿的毒性和疾病。我们的长期目标是确定通过燕麦处理药物/毒素的分子机制。我们有强有力的初步数据表明，燕麦受到细胞信号通路的剧烈调节，这种调节与燕麦细胞表面呈现的动态变化相结合，表明膜运输是转运体动态平衡和调节的基础。然而，这种监管背后的机制是完全未知的。这一应用的主要目的是确定控制OAT1转运的细胞和分子机制，并评估这种调控形式的生理和病理生理学相关性。概述了四个具体目标(SA)。在SA-1中，我们将分析基础和调节的OAT1转运动力学。在SA-2中，我们将剖析OAT1贩运所涉及的路径。在SA-3中，我们将确定与其运输有关的OAT1序列中的结构基序。在SA-4中，我们将评估OAT1转运在调节药物转运活性中的生理学和病理生理学相关性。生物化学和分子生物学相结合的方法将用于拟议的组织切片和培养细胞的研究。了解燕麦的运输和调控是药物转运领域的一个新焦点，这将对未来旨在最大化治疗效果和将毒性降至最低的策略的设计产生重大影响，并将有助于深入了解肾、肝、神经和胎儿毒性和疾病的分子、细胞和临床基础。与公共健康相关：有机阴离子转运体(OAT)家族调节多种环境毒素和临床重要药物的吸收、分布和排泄，包括抗HIV治疗药物、抗肿瘤药物、抗生素、抗高血压药物和抗炎药物，因此对哺乳动物物种的生存至关重要。已鉴定出6种燕麦(OAT1、OAT2、OAT3、OAT4、OAT5和OAT6)，并在肾脏、肝脏、脑和胎盘中检测到它们的表达。燕麦在这些器官中的功能障碍极大地导致了肾、肝、神经和胎儿的毒性和疾病。我们的长期目标是确定通过燕麦处理药物/毒素的分子机制。我们有强有力的初步数据表明，燕麦受到细胞信号通路的剧烈调节，这种调节与燕麦细胞表面呈现的动态变化相结合，表明膜运输是转运体动态平衡和调节的基础。然而，这种监管背后的机制是完全未知的。这一应用的主要目的是确定控制OAT1转运的细胞和分子机制，并评估这种调控形式的生理和病理生理学相关性。了解燕麦的运输和调控是药物转运领域的一个新焦点，这将对未来旨在最大化治疗效果和将毒性降至最低的策略的设计产生重大影响，并将有助于深入了解肾、肝、神经和胎儿毒性和疾病的分子、细胞和临床基础。

DESCRIPTION (provided by applicant): The organic anion transporter (OAT) family mediates the absorption, distribution, and excretion of a diverse array of environmental toxins, and clinically important drugs, including anti-HIV therapeutics, anti-tumor drugs, antibiotics, anti-hypertensives, and anti- inflammatories, and therefore is critical for the survival of mammalian species. Six OATs have been identified (OAT1, OAT2, OAT3, OAT4, OAT5, and OAT6) and their expression detected in kidney, liver, brain and placenta. OAT dysfunction in these organs significantly contributes to the renal, hepatic, neurological and fetal toxicity and disease. Our long-term goal is to define the molecular mechanisms underlying drug/toxin disposition through OATs. We have strong preliminary data to show that OATs are subjected to acute regulation by cellular signaling pathways and that such regulation is coupled to dynamic changes in OAT cell-surface presentation, suggesting that membrane trafficking is fundamental to transporter homeostasis and regulation. However, the mechanisms underlying this regulation are completely unknown. The major goal of this application is to determine the cellular and molecular mechanisms governing OAT1 trafficking, and to evaluate the physiological and pathophysiological relevance of this form of regulation. Four Specific Aims (SAs) are outlined. In SA-1, we will analyze basal and regulated OAT1 trafficking kinetics. In SA-2, we will dissect the pathways involved in OAT1 trafficking. In SA-3, we will identify the structural motifs in OAT1 sequence involved in their trafficking. In SA-4, we will evaluate the physiological and pathophysiological relevance of OAT1 trafficking in regulation of drug transport activity. Combined approaches of biochemistry and molecular biology will be employed for the proposed studies in tissue slices, and cultured cells. Understanding the trafficking and regulation of OATs, a novel focus in drug transport field, will have significant impact on the future design of strategies aimed at maximizing therapeutic efficacy and minimizing toxicity, and will permit insight into the molecular, cellular, and clinical bases of renal, hepatic, neurological and fetal toxicity and disease. PUBLIC HEALTH RELEVANCE: The organic anion transporter (OAT) family mediates the absorption, distribution, and excretion of a diverse array of environmental toxins, and clinically important drugs, including anti-HIV therapeutics, anti-tumor drugs, antibiotics, anti-hypertensives, and anti- inflammatories, and therefore is critical for the survival of mammalian species. Six OATs have been identified (OAT1, OAT2, OAT3, OAT4, OAT5, and OAT6) and their expression detected in kidney, liver, brain and placenta. OAT dysfunction in these organs significantly contributes to the renal, hepatic, neurological and fetal toxicity and disease. Our long-term goal is to define the molecular mechanisms underlying drug/toxin disposition through OATs. We have strong preliminary data to show that OATs are subjected to acute regulation by cellular signaling pathways and that such regulation is coupled to dynamic changes in OAT cell-surface presentation, suggesting that membrane trafficking is fundamental to transporter homeostasis and regulation. However, the mechanisms underlying this regulation are completely unknown. The major goal of this application is to determine the cellular and molecular mechanisms governing OAT1 trafficking, and to evaluate the physiological and pathophysiological relevance of this form of regulation. Understanding the trafficking and regulation of OATs, a novel focus in drug transport field, will have significant impact on the future design of strategies aimed at maximizing therapeutic efficacy and minimizing toxicity, and will permit insight into the molecular, cellular, and clinical bases of renal, hepatic, neurological and fetal toxicity and disease.