The plasma membrane monoamine transporter (PMAT): expression and role in mIBG disposition in neuroblastoma

质膜单胺转运蛋白 (PMAT)：在神经母细胞瘤中 mIBG 处置中的表达和作用

基本信息

批准号：
9698122
负责人：
Joanne Wang
金额：
$ 11.14万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-08-01 至 2021-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9698122
关键词：
1-Methyl-4-phenylpyridinium Amines Animal Model Basic Science Biguanides Biology Blood Brain Cations Cell membrane Cerebrospinal Fluid Chemicals Clinical Colitis Colon Development Diffusion Drug or chemical Tissue Distribution Drug usage Exhibits Gastrointestinal tract structure Gene Deletion Gene Targeting Genetic Goals HRH2 gene Histamine H2 Receptors Histologic Hormones Human Hypoglycemic Agents In Vitro Inflammation Inflammatory Bowel Diseases Inflammatory Response Intestinal permeability Intestines Knockout Mice Knowledge Laboratories Lead Light Liver Location Mediating Metformin Molecular Morphology Mus Neuroblastoma Neurotoxins Neurotransmitters Oral Organic Cation Transporter Organic Cation Transporter 1 POU2F1 gene POU2F2 gene Paraquat Pathogenesis Pathogenicity Pathologic Pathway interactions Pharmaceutical Preparations Pharmacology Physiological Physiology Platinum Play Predisposition Process Resources Role Serotonin Signal Pathway Site Specificity Structure Structure of choroid plexus Substrate Specificity Therapeutic Tissue membrane Tissues Toxic effect Toxin Validation Work Xenobiotics absorption base blood cerebrospinal fluid barrier design disorder prevention drug development drug discovery gastrointestinal high throughput screening hydrophilicity in vivo inhibitor/antagonist insight knockout animal monoamine mouse model new therapeutic target novel small molecule inhibitor solute stable cell line tool uptake

项目摘要

Many drugs (e.g. biguanide antihyperglycemics, histamine H2 receptor blockers, platinum-based chemotherapeutics etc.) and toxins (e.g. MPP+, paraquat) are hydrophilic organic cations (OCs) that do not readily cross cell membranes by passive diffusion. Organic cation transporters play important roles in the disposition, efficacy and toxicity of these OC xenobiotics. These transporters are also likely to be involved in various physiological pathways through their uptake of endogenous bioactive amines. The plasma membrane monoamine transporter (PMAT) is a new polyspecific organic cation transporter first cloned and characterized in our laboratory. The physiologic substrates of PMAT are the monoamine neurotransmitters with serotonin (5- HT) being the most preferred substrate. PMAT also transports many structurally diverse cationic xenobiotics including the neurotoxin MPP+ and therapeutic drugs such as metformin. PMAT is highly expressed in the brain and the gastrointestinal tract, and has overlapping substrate specificity with organic cation transporters 1- 3 (OCT1-3). Our previous molecular and cellular work strongly supports a role of PMAT in 5-HT signaling pathways and in OC transport at barrier tissues including choroid plexus that forms the blood- cerebrospinal fluid (CSF) barrier. However, these studies are limited by their in vitro design, and the physiological function of PMAT and its in vivo significance in brain OC disposition remain undefined. We have recently created a novel PMAT knockout mouse model, which provides a unique resource to evaluate the roles and significance of PMAT in vivo. Using a chemical biology approach, we also identified a set of promising specific small molecule inhibitors for PMAT. More excitingly, the PMAT null mice exhibited physiological and histological abnormalities in the colon which could represent early signs associated with the development of inflammatory bowel disease. Because 5-HT is a key gut hormone known to be involved in the pathogenesis of inflammatory bowel disease, these observations suggest a protective role of PMAT against colitis likely through 5-HT mediated pathway. In this competing renewal application, we propose to use our novel animal model and unique chemical tools to investigate the physiological, pharmacological and pathological function of PMAT. In Aim 1, we will further characterize and validate highly potent and selective small molecule inhibitors for PMAT. In Aim 2, we will use our knockout animal model and specific chemical inhibitors to investigate the role of PMAT in mediating OC efflux at the blood-CSF barrier. Lastly, in Aim 3, we will investigate the pathogenic role of PMAT in the development of inflammatory response in the gut. The proposed studies will greatly enhance our understandings of the in vivo roles and significance of a novel organic cation transporter. These studies will shed new light on the determinants influencing brain disposition of OC drugs and toxins. Finally, our studies will elucidate the pathophysiologic role of PMAT in the gut and offer new insights into genetic factors influencing host susceptibility to inflammatory bowel disease.

许多药物（例如双胍类降糖药、组胺 H2 受体阻滞剂、铂类药物）化疗药物等）和毒素（例如 MPP+、百草枯）是亲水性有机阳离子 (OC)，不会通过被动扩散很容易穿过细胞膜。有机阳离子转运蛋白在这些 OC 异生素的处置、功效和毒性。这些运输商也可能参与通过摄取内源性生物活性胺来实现各种生理途径。质膜单胺转运蛋白（PMAT）是一种新型多特异性有机阳离子转运蛋白，首次被克隆和表征在我们的实验室。 PMAT 的生理底物是单胺神经递质和血清素（5- HT) 是最优选的底物。 PMAT 还运输许多结构多样的阳离子异生物质包括神经毒素 MPP+ 和二甲双胍等治疗药物。 PMAT 高度表达于大脑和胃肠道，并与有机阳离子转运蛋白具有重叠的底物特异性 1- 3（10 月 1 日至 3 日）。我们之前的分子和细胞工作强烈支持 PMAT 在 5-HT 信号传导中的作用途径和 OC 在屏障组织（包括形成血脑脊髓的脉络丛）的转运液体（脑脊液）屏障。然而，这些研究受到体外设计和生理功能的限制。 PMAT 及其在脑 OC 处置中的体内意义仍不清楚。我们最近创作了一本小说 PMAT 敲除小鼠模型，为评估 PMAT 的作用和意义提供了独特的资源 PMAT 体内。使用化学生物学方法，我们还确定了一组有前途的特定小分子 PMAT 分子抑制剂。更令人兴奋的是，PMAT 缺失小鼠表现出生理和组织学特征结肠异常可能代表与炎症发展相关的早期迹象肠道疾病。因为 5-HT 是一种关键的肠道激素，已知参与炎症的发病机制肠道疾病，这些观察结果表明 PMAT 可能通过 5-HT 对结肠炎发挥保护作用介导途径。在这个竞争性的更新应用中，我们建议使用我们的新颖动物模型和独特的化学工具来研究 PMAT 的生理、药理和病理功能。在目标 1，我们将进一步表征和验证 PMAT 的高效、选择性小分子抑制剂。在目标 2 中，我们将使用我们的基因敲除动物模型和特定化学抑制剂来研究 PMAT 介导血脑脊液屏障处的 OC 流出。最后，在目标 3 中，我们将研究致病作用 PMAT 在肠道炎症反应发展中的作用。拟议的研究将大大提高我们对新型有机阳离子转运蛋白的体内作用和重要性的理解。这些研究将为影响大脑对 OC 药物和毒素的处置的决定因素提供新的线索。最后，我们的研究将阐明 PMAT 在肠道中的病理生理作用，并为遗传因素提供新的见解影响宿主对炎症性肠病的易感性。