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）的广泛使用导致草甘膦​​进入食物链，并且 导致人体血清和尿液水平随着时间的推移而增加。此次曝光引发了众多争议 草甘膦会导致多种疾病，从多种癌症到影响人类发育和 生殖。然而，草甘膦进入人体细胞的机制尚不清楚。在酵母中，进口 由于其结构相似，通过谷氨酸/天冬氨酸 (D/E) 转运蛋白发生。草甘膦是 人们认为不会对人类产生急性影响，因为它们缺乏产生芳香的莽草酸途径 氨基酸（WYF），在草甘膦的存在下受到抑制，而人类反而获得芳香 通过饮食或肠道微生物组提供氨基酸。草甘膦商品制剂的差异 使研究变得复杂，因为 GBH 具有增加组织渗透性的表面活性剂。酵母罐头 当补充 (WYF) 时，绕过莽草酸途径的抑制，从而允许评估 表面活性剂的作用，或者更有可能发现未知的草甘膦目标。我们的初步研究有 发现调节线粒体、DNA 损伤和细胞周期的基因在 GBH 中受到差异性调节 治疗。长期目标是确定草甘膦进入细胞、大脑、 以及影响线粒体代谢的其他组织。该应用程序的目标是确定如何 线粒体代谢受到模型中单独草甘膦和商业制剂的影响 酿酒酵母生物体。我们的中心假设是草甘膦的转运是由于模仿 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，尤其是 线粒体内。该提案的基本原理是草甘膦对线粒体的影响具有 生物化学基础并将提供对脊椎动物细胞效应的机制理解。 提出的具体目标是 1. 测量草甘膦进入不同区域的不同区域的情况 突变体以及添加 D/E 如何挽救草甘膦的生长抑制 2. 测量特定的变化 草甘膦处理细胞中的线粒体代谢物（ATP 和 NADH）。所提出的研究具有创新性 因为提出的假设是使用无偏见的实验，例如全基因组关联， 转录组学和实验室进化实验以确定细胞外和细胞内的机制 使用 D/E 转运蛋白转运草甘膦。草甘膦在运输过程中模拟 D/E 氨基酸，因此它可能 影响其他使用 D/E 的酶，特别是线粒体中的酶。在植物、真菌和细菌中，D/E 转运蛋白都与草甘膦转运有关，并且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 转运蛋白和保守的线粒体 使用 D/E 的蛋白质，这可能是草甘膦的脱靶，导致一系列声称可以预防的疾病 是由草甘膦引起的。