Choroid Plexus as a Target in Metal-Induced Neurotoxicity

脉络丛作为金属诱导神经毒性的靶点

• 批准号: 7417332
• 负责人: WEI ZHENG
• 金额: $ 7.69万
• 依托单位: PURDUE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-03-01 至 2009-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7417332
• 关键词: 3' Untranslated Regions; Affect; Area; Binding; Biological Assay; Biological Markers; Blood; Blood - brain barrier anatomy; Blood capillaries; Body Fluids; Brain; Carrier Proteins; Cell Line; Cell membrane; Cells; Cerebrospinal Fluid; Chronic; Condition; Confocal Microscopy; Disease; Electrophoretic Mobility Shift Assay; Epithelial; Epithelium; Exposure to; Ferritin; Functional disorder; Funding; Gene Expression; Gene Silencing; Genetic Transcription; Goals; Grant; Heterogeneous Nuclear RNA; Homeostasis; Human; In Vitro; Iron; Iron Regulatory Protein 1; Iron-Regulatory Proteins; Kinetics; Laboratory Research; Localized; Location; Manganese; Messenger RNA; Metabolic Diseases; Metals; Modeling; Molecular; Neurodegenerative Disorders; Neurons; Nuclear; Parkinson Disease; Parkinsonian Disorders; Peer Review; Perfusion; Polymerase Chain Reaction; Population; Progress Reports; Proteins; RNA; Rate; Rattus; Regulation; Reporting; Research; Research Personnel; Research Support; Reverse Transcriptase Polymerase Chain Reaction; Role; Rotenone; Running; SLC11A2 gene; Score; Serum; Side; Small Interfering RNA; Steel; Structure; Structure of choroid plexus; Study Section; System; Techniques; Testing; Time; Transferrin Receptor; US Army Medical Research and Material Command; Welding; Western Blotting; base; blood cerebrospinal fluid barrier; capillary; career; divalent metal; early onset; in vivo; insight; knock-down; mRNA Transcript Degradation; metal transporting protein 1; neurotoxicity; novel; programs; research study; stem; toxicant; uptake

DESCRIPTION (provided by applicant): Altered brain iron (Fe) homeostasis has been shown in idiopathic Parkinson's disease (IPD) and in manganese (Mn)-induced Parkinsonism. The current proposal continues the central theme of our long-time research goal, i.e., to explore the role of brain barrier systems in metal-induced neurotoxicities. Divalent metal transporter-1 (DMT1) and metal transport protein-1 (MTP1) are two newly discovered metal transporters and function to transport metals across the cell membrane. In the Progress Report, we have demonstrated the presence of DMT1 and MTP1 in the choroid plexus, where the blood-cerebrospinal fluid (CSF) barrier (BCB) is located. We have also observed that Mn exposure increases DMT1 expression and mobilizes subcellular MTP1 in the BCB epithelia. However, the questions as to where the DMT1 and MTP1 are subcellularly co-localized in the BCB, how they function in concert to respond to divalent-metal fluxes on both sides of the BCB, by what mechanism Mn exposure alters the expression and function of both transporters, and how the dysregulation of DMT1 and MTP1 in the BCB by Mn exposure affects brain homeostasis of Fe and Mn, remain mysterious. Thus, to understand the structural functionality of DMT1 and MTP1 in the brain barrier and their dysfunction-associated neuronal disorders, we hypothesize that the altered expression of DMT1 and MTP1 in the choroid plexus following Mn exposure contributes to Mn- induced Fe metabolism disorder in the CSF. Our specific aims are: (1) to explore whether DMT1 and MTP1 control the direction of Fe transport at the BCB by investigating the subcellular location of DMT1 and MTP1 in choroidal epithelia, by blocking or inducing DMT1 and MTP1 expression to determine the direction of Fe and Mn transport at BCB, and by using siRNA technique to silence the genes encoding DMT1 and MTP1 to investigate Fe and Mn uptake and transport kinetics under DMT1 or MTP1 knock-down conditions; (2) to explore whether in vivo chronic Mn exposure distorts the expression of DMT1 and MTP1 in the BCB and selected regional blood-brain barrier and leads to increased fluxes of Fe between the blood and CSF, by using a rat chronic Mn exposure model and by a ventriculo-cisternal perfusion technique; and (3) to explore whether Mn exposure interferes the binding of iron-regulatory proteins to mRNAs of DMT1 and MTP1, since the stem-loop structure exists in 3'-untranslated regions (UTR) and 5'-UTR in DMT1 and MTP1 mRNA, respectively. Studies proposed in this application will define the inter-relationship between DMT1 and MTP1 in the BCB with regard to their subcellular locations, roles in transport of divalent metals at the BCB, and their regulation as affected by Mn exposure; will provide insight into the molecular mechanism by which Mn affects divalent Fe transport by brain barriers; and will ultimately provide a better understanding of Fe dysfunction-related neuronal diseases such as IPD.

描述（由申请人提供）：特发性帕金森氏病（IPD）和锰（MN）引起的帕金森氏症已显示出改变的脑铁（FE）稳态。当前的建议继续我们长期研究目标的中​​心主题，即探索脑屏障系统在金属诱导的神经毒性中的作用。二价金属转运蛋白1（DMT1）和金属转运蛋白1（MTP1）是两个新发现的金属转运蛋白，并且功能可在整个细胞膜上运输金属。在进度报告中，我们证明了在脉络丛中存在DMT1和MTP1，其中血流脊髓液（CSF）屏障（BCB）所在。我们还观察到，MN暴露会增加DMT1的表达并动员BCB上皮中的亚细胞MTP1。但是，关于DMT1和MTP1在BCB中的何处的问题，它们如何协同作用，以响应BCB两侧的二价金属通量，MN暴露的机制暴露，通过哪种机制来改变转运蛋白的表达和功能，以及如何通过DMT1和MCB的功能来影响BC1和MTP1的功能，并在BCS的失调中受到影响。 MN，保持神秘。因此，为了了解脑屏障中DMT1和MTP1的结构功能及其功能障碍相关的神经元疾病，我们假设在MN暴露后，MN-诱导MN-诱导的FE代谢疾病在MN暴露后，DMT1和MTP1的表达改变了DMT1和MTP1的表达。我们的具体目的是：（1）探索DMT1和MTP1是否通过研究脉络膜上皮中DMT1和MTP1的亚细胞位置是否通过脉络膜上皮中的亚细胞位置来控制Fe运输的方向，通过阻止DMT1和MTP1表达来阻止或诱导MTP1的表达，以确定在BCB和MN技术的方向上，以确定sird sird sinique nisique ncod sinique nisique nisique nisique nisique nisique nisique， MTP1调查DMT1或MTP1敲低条件下的Fe和Mn吸收和运输动力学； （2）探索体内慢性MN暴露是否会扭曲BCB中DMT1和MTP1的表达，并选择了通过使用大鼠慢性MN暴露模型和通过心室炎症模型和心室灌注技术，导致血液和CSF之间的Fe中的Fe通量增加； （3）探索MN暴露是否会干扰铁调节蛋白与DMT1和MTP1的mRNA的结合，因为分别在3'-非翻译区域（UTR）（UTR）和DMT1和MTP1 mRNA中存在Stem-Loop结构。本应用中提出的研究将定义BCB中DMT1和MTP1之间的相互关系，这些研究在其亚细胞位置，BCB的二价金属运输中的作用以及受MN暴露的影响；将洞悉MN影响脑屏障的二价Fe传输的分子机制；并最终将更好地了解与FE功能障碍相关的神经元疾病，例如IPD。