Molecular Determinants of Pyrethroid Neurotoxicity

拟除虫菊酯神经毒性的分子决定因素

基本信息

批准号：
7242133
负责人：
DAVID M SODERLUND
金额：
$ 29.89万
依托单位：
CORNELL UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-04-01 至 2012-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7242133
关键词：
Action Potentials Acute Affect Agriculture Amino Acid Sequence Animals Binding Cells Class Condition Development Drug or chemical Tissue Distribution Electrodes Exhibits Facility Construction Funding Category Family Funding Human Insect Vectors Insecta Insecticides Intoxication Kinetics Mammalian Cell Maps Mediating Modeling Modification Molecular Molecular Structure Multigene Family Mutate Myocardium Nature Nerve Nervous system structure Neurons Oocytes Permeability Pharmacology Property Protein Isoforms Public Health Rana Rattus Regulation Research Research Personnel Resistance Role Severities Site Site-Directed Mutagenesis Skeletal system Sodium Sodium Channel Testing Tissues Toxic effect Xenopus laevis Xenopus oocyte base human disease insight member neurotoxic neurotoxicity patch clamp programs pyrethroid receptor voltage voltage clamp

项目摘要

DESCRIPTION (provided by applicant): Synthetic pyrethroids, an important class of neurotoxic insecticides used worldwide in agriculture and public health, cause toxic effects in animals by modifying the normal function of voltage-sensitive sodium channels. Sodium channels in mammalian tissues exist as multiple isoforms that exhibit differential tissue distribution and developmental regulation and are encoded by members of a multigene family. Previous studies of pyrethroid action have not considered the differential sensitivity of sodium channel isoforms as a determining factor in the toxicity of these compounds. The proposed research will test the hypothesis that differences in the pyrethroid sensitivity of mammalian sodium channel isoforms are important determinants of the nature and severity of pyrethroid intoxication. Specific experimental aims are: (1) to define the actions of pyrethroid insecticides on cloned rat sodium channel isoforms expressed in frog (Xenopus laevis) oocytes or transfected mammalian cells; (2) to compare the actions of pyrethroids on orthologous rat and human sodium channel isoforms expressed in Xenopus oocytes or trnasfected mammalian cells; and (3) to map the the structural determinants of pyrethroid action by the construction, functional expression and pharmacological characterization of specifically mutated sodium channels. Cloned sodium channel isoforms will be expressed in Xenopus oocytes or transiently transfected mammalian cells (e.g., HEK-293) and the actions of pyrethroid insecticides on expressed channels will be assessed using electrophysiological recordings of macroscopic sodium currents under two-electrode voltage-clamp or whole cell patch-clamp conditions. Structural determinants of pyrethroid sensitivity will be identified by site-directed mutagenesis, expression, and pharmacological comparison of native a mutated sodium channel isoforms. Results of these studies will define the role of different sodium channel isoforms in pyrethroid toxicity, establish whether rat sodium channels are valid toxicological models for the sensitivity of human sodium channels to pyrethroids, and identify sodium channel domains that determine pyrethroid sensitivity.

描述（由申请人提供）：合成拟除虫菊酯，这是一类重要的神经毒性杀虫剂在全球范围内在农业和公共卫生中使用，通过修改电压敏感钠通道的正常功能，从而引起动物的毒性作用。哺乳动物组织中的钠通道作为多种同工型存在，这些同工型表现出差异组织分布和发育调节，并由多基因家族的成员编码。先前对拟除虫菊酯作用的研究并未将钠通道同工型的差异敏感性视为这些化合物毒性的决定因素。拟议的研究将检验以下假设：哺乳动物钠通道同工型的拟除虫菊酯敏感性的差异是拟除虫菊酯中毒的性质和严重程度的重要决定因素。具体的实验目的是：（1）定义在青蛙（Xenopus laevis）卵母细胞或转染的哺乳动物细胞中表达的克隆大鼠钠通道同工型的克隆大鼠钠通道同工型的作用；（2）比较拟甲虫素对在异武肠卵母细胞或TRNASFAINT的哺乳动物细胞中表达的直系同源大鼠和人钠的同工型的作用；（3）通过特异性突变的钠通道的结构，功能表达和药理表征来绘制拟除虫菊酯作用的结构决定因素。 Cloned sodium channel isoforms will be expressed in Xenopus oocytes or transiently transfected mammalian cells (e.g., HEK-293) and the actions of pyrethroid insecticides on expressed channels will be assessed using electrophysiological recordings of macroscopic sodium currents under two-electrode voltage-clamp or whole cell patch-clamp conditions.拟除虫菊酯敏感性的结构决定因素将通过定位定向的诱变，表达和药理学比较来鉴定出天然突变的钠通道同工型。这些研究的结果将定义不同钠通道同工型在拟除虫菊酯毒性中的作用，确定大鼠钠通道是否是人类钠通道对吡啶会敏感性的有效毒理学模型，并识别确定钠the虫敏感性的钠通道结构域。