Amino acid mimicry: Insights into glyphosate transport and toxicity to mitochondria

氨基酸拟态：深入了解草甘膦转运和线粒体毒性

• 批准号: 10573869
• 负责人: Jennifer Gallagher
• 金额: $ 7.6万
• 依托单位: WEST VIRGINIA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-10 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10573869
• 关键词: Acute; Affect; Amino Acids; Animals; Aromatic Amino Acids; Aspartate; Bacteria; Binding; Binding Proteins; Biochemical; Brain; Bypass; Cell Cycle; Cells; Chemical Exposure; Cytoplasm; DNA Damage; Data; Data Set; Diet; Disease; Down-Regulation; Enzymes; Evolution; Food Chain; Food Contamination; Formulation; Future; Genes; Genetic; Glutamate Transporter; Glutamates; Goals; Growth; Health; Herbicides; Human; Human Development; Malate-Aspartate Shuttle Pathway; Malates; Measures; Metabolic Diseases; Metabolism; Mitochondria; Mitochondrial Proteins; Modeling; NADH; Nutrient; Nutrient availability; Occupational Exposure; Organ; Organism; Pathway interactions; Penetration; Plants; Preparation; Regulation; Repression; Reproduction; Research; Resistance; Role; Saccharomyces cerevisiae; Site; Structure; Supplementation; Testing; Time; Tissues; Toxic effect; Transportation; Urine; Yeasts; cancer type; experimental study; exposed human population; fungus; genome wide association study; glyphosate; gut microbiome; innovation; insight; mimicry; mitochondrial metabolism; model organism; mutant; nervous system disorder; permease; sensor; shikimate; surfactant; transcriptomics

Extensive use of glyphosate-based herbicides (GBH) has led to glyphosate entering the food chain, and causing human sera and urine levels to increase over time. This exposure has led to numerous claims that glyphosate causes diseases ranging from multiple types of cancer to affecting human development and reproduction. However, no mechanism of glyphosate import into human cells is known; in yeast, importation occurs through the glutamate/ aspartate (D/E) transporters due to its structural resemblance. Glyphosate is thought not to have acute effects on humans because they lack the shikimate pathway that produces aromatic amino acids (WYF), which is inhibited in the presence of glyphosate, and humans instead acquire aromatic amino acids through diet or the gut microbiome. The differences in commercial preparations of glyphosate have complicated the studies because GBHs have surfactants that increase tissue penetration. Yeast can bypass the inhibition of the shikimate pathway when supplemented with (WYF), which permits the assessment of the role of surfactants or, more likely, discover the unknown glyphosate targets. Our initial studies have found that genes regulating mitochondria, DNA damage, and the cell cycle are differentially regulated in GBH treatments. The long-term goal is to identify the glyphosate transportation mechanisms into cells, the brain, and other tissues that affect mitochondrial metabolism. This application's objective is to determine how mitochondrial metabolism is affected by glyphosate alone and in commercial formulations in the model organism S. cerevisiae. Our central hypothesis is that the transport of glyphosate is due to mimicry of glutamate and aspartate; thus, it will affect other enzymes that utilize glutamate and aspartate, especially within the mitochondria. The rationale of this proposal is that mitochondrial effects of glyphosate have a biochemical basis and will provide a mechanistic understanding of cellular effects in vertebrate species. Specific aims proposed are 1. Measure the import of glyphosate into different compartments in different mutants and how adding D/E rescues growth inhibition from glyphosate 2. Measure changes in specific mitochondrial metabolites (ATP and NADH) in glyphosate treated cells. The proposed research is innovative because the hypothesis proposed is using unbiased experiments, such as genome-wide association, transcriptomics, and In-Lab Evolution experiments to determine the mechanism of extra- and intracellular glyphosate transport using D/E transporters. Glyphosate mimics D/E amino acids in transport, so it likely affects other enzymes that use D/E, particularly in the mitochondria. In plants, fungi, and bacteria, D/E transporters have all been implicated in glyphosate transport and glyphosate affecting mitochondrial functions. While humans do not have the shikimate pathway, they have D/E transporters, and conserved mitochondrial proteins that use D/E, which may be the off-targets of glyphosate leading to the range of diseases claimed to have been caused by glyphosate.

草甘膦除草剂(GBH)的广泛使用已导致草甘膦进入食物链，以及 导致人类的血清和尿液水平随着时间的推移而增加。这种暴露导致了许多人声称 草甘膦会导致多种疾病，从多种癌症到影响人类发育和 繁殖。然而，目前尚不清楚草甘膦进入人体细胞的机制；在酵母中， 由于其结构相似，通过谷氨酸/天冬氨酸(D/E)转运体发生。草甘膦是 被认为对人类不会有严重影响，因为它们缺乏产生芳香物质的莽草酸途径 氨基酸(Wyf)，它在草甘膦存在时被抑制，而人类反而获得芳香族 氨基酸通过饮食或肠道微生物群。草甘膦商品化制剂的差异 使研究复杂化，因为GBHS具有增加组织渗透率的表面活性剂。酵母罐头 当添加(Wyf)时，绕过莽草酸途径的抑制，这允许评估 或者，更有可能的是，发现未知的草甘膦靶标。我们的初步研究已经 发现调控线粒体、DNA损伤和细胞周期的基因在GBH中受到不同的调控 治疗。长期目标是确定草甘膦进入细胞、大脑、 以及其他影响线粒体新陈代谢的组织。此应用程序的目标是确定如何 在模型中，线粒体新陈代谢受到草甘膦单独和商业配方的影响 有机体酿酒酵母。我们的中心假设是草甘膦的运输是由于 谷氨酸和天冬氨酸；因此，它会影响其他利用谷氨酸和天冬氨酸的酶，特别是 在线粒体内。这一建议的基本原理是草甘膦的线粒体效应具有 生物化学基础，并将提供对脊椎动物物种中细胞效应的机械理解。 提出的具体目标是1.衡量草甘膦在不同隔间的进口量 突变体以及添加D/E如何解救草甘膦对生长的抑制2.测量特定的变化 草甘膦处理细胞中的线粒体代谢产物(ATP和NADH)。建议的研究具有创新性。 因为提出的假设是使用无偏见的实验，例如全基因组关联， 转录学和室内进化实验来确定细胞外和细胞内的机制 使用D/E转运体的草甘膦转运。草甘膦在运输中模仿D/E氨基酸，所以它很可能 影响其他使用D/E的酶，特别是在线粒体中。在植物、真菌和细菌中，D/E 转运蛋白都与草甘膦转运有关，草甘膦影响线粒体功能。 虽然人类没有莽草酸途径，但他们有D/E转运体，并保守的线粒体 使用D/E的蛋白质，这可能是草甘膦的非靶标，导致声称的一系列疾病 是由草甘膦引起的。