Molecular Mechanisms of Endocrine Disruption in Bass

低音内分泌干扰的分子机制

• 批准号: 7407982
• 负责人: Nancy D Denslow
• 金额: $ 37.32万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7407982
• 关键词: 17p; Acute; Adult; Adverse effects; Affect; Agonist; Androgen Receptor; Androgens; Animals; Aromatase; Back; Bass; Binding; Biochemical; Biochemical Pathway; Biological Markers; CYP11A1 gene; CYP19A1 gene; CYP3A4 gene; Cells; Chemicals; Cholesterol Monooxygenase (Side-Chain-Cleaving); Cyclic AMP; Data; Dichlorodiphenyl Dichloroethylene; Dieldrin; Dose; Ecosystem; Electrophoretic Mobility Shift Assay; End Point; Endocrine Disruptors; Endocrine disruption; Endocrine system; Enzymes; Estradiol; Estrogen Receptors; Exhibits; Exposure to; Farming environment; Feedback; Fishes; Florida; Functional disorder; Gene Expression; Gene Proteins; Genetic Transcription; Genomics; Goals; Gonadal Steroid Hormones; Health; Hepatic; Homeostasis; Hormone Receptor; Hormones; Human; Impairment; In Vitro; Life; Link; Measures; Mediating; Messenger RNA; Metabolic Pathway; Metabolism; Methodology; Methods; Methoxychlor; Micropterus; Microsomes; Modeling; Molecular; Molecular Mechanisms of Action; Monitor; Nomenclature; Pathway interactions; Pattern; Pesticides; Plasma; Process; Protein Isoforms; Proteins; Proteomics; Protocols documentation; Range; Reaction Time; Receptor Signaling; Regulation; Reporting; Reproduction; Research; Research Personnel; Role; Sentinel; Site; Small Interfering RNA; Sperm Motility; Steroid biosynthesis; Steroids; Testing; Testosterone; Time; Tissues; Toxaphene; Vertebrates; Vesicle; Work; aquatic organism; cytochrome P450 3A; design; egg; enzyme activity; field study; hypothalamic pituitary gonadal axis; in vivo; knock-down; novel; organochlorine pesticide; organochlorine pesticide exposure; preference; prevent; programs; promoter; protein expression; receptor; receptor function; reproductive; reproductive function; research study; response; sperm function; steroid hormone receptor; steroid metabolism; steroidogenic acute regulatory protein; superfund site; transcription factor

Transient and permanent reproductive dysfunction in fish has been linked to chemicals that disrupt the endocrine system, but the mechanisms involved are unclear. Many endocrine-disrupting chemicals (EDCs) interact with sex hormone receptors by acting as agonists to induce gene expression at inappropriate times or act as antagonists to prevent the normal functioning of the receptors. Other EDCs may act indirectly by altering the processes involved in regulating sex steroid synthesis and metabolism. Poor reproduction and altered plasma hormone levels have been observed in largemouth bass living in ecosystems polluted with organochlorine pesticides (OCPs), including the Superfund site at Lake Apopka and its surrounding muck farms, suggesting that OCP exposure has adversely affected their reproduction. In past research, we have identified three estrogen receptors (a, pi, and (32) in largemouth bass, which exhibit tissue specific expression and respond differently to 17-p-estradiol at the message and activity level. These differences are important to control normal reproductive function. We have evidence that EDCs can alter their normal expression and activity patterns, possibly disrupting reproduction. In addition, we have preliminary evidence that expression of enzymes involved in the synthesis and metabolism of EDCs is affected by the OCPs. The proposed studies will test the central hypothesis that exposure of largemouth bass to concentrations of OCPs found in the Lake Apopka region disrupts endocrine system function by sex hormone receptor mediated and sex hormone receptor independent mechanisms. In this proposal, we have designed a set of interrelated experiments from the organismal level where pleiotropic effects of OCPs can be measured to the cellular level where specific molecular mechanisms of action can be assessed. We are exposing largemouth bass to methoxychlor (and its metabolites), p,p' DDE, dieldrin and toxaphene. Our specific aims include 1: Develop biomarkers of exposure to organochlorinated pesticides in vivo, via the use of microarrays and novel proteomics methodologies; 2: Determine the effect of in vivo OCP exposure on LME steroid synthesis and metabolism; and 3: Evaluate the effects of OCPs on the molecular mechanisms of action of the three estrogen receptors. We plan on using exposures to compounds with known modes of action as controls to determine mode of action specific gene expression patterns against which we will compare the patterns of gene expression changes induced by the OCPs. We will check these pattern changes against reproductive endpoints including the ability of eggs to mature (germinal vesicle breakdown) and sperm function (sperm motility). Fish are useful as sentinels of environmental quality and are perfect models to monitor adverse effects in reproduction caused by contaminants in superfund sites. By extrapolation fish can report on the potential of OCPs to harm human health.

鱼类短暂的和永久性的生殖功能障碍与化学物质有关，这些化学物质破坏了 内分泌系统，但涉及的机制尚不清楚。许多内分泌干扰物(EDCs) 作为激动剂与性激素受体相互作用，在不适当的时间诱导基因表达 或充当拮抗剂以阻止受体的正常功能。其他EDC可能通过以下方式间接发挥作用 改变涉及调节性类固醇合成和新陈代谢的过程。繁殖力差， 观察到生活在受污染生态系统中的大口黑鱼的血浆激素水平发生了变化 有机氯农药(OCP)，包括超级基金在阿波卡湖及其周围的淤泥 这表明接触有机氯农药对它们的繁殖产生了不利影响。 在过去的研究中，我们已经在大口黑鱼中鉴定出三种雌激素受体(a，pi和(32))，它们 表现出组织特异性表达，并在信息和活动水平上对17-p-雌二醇有不同的反应。 这些差异对于控制正常的生殖功能很重要。我们有证据表明EDC可以 改变它们的正常表达和活动模式，可能会扰乱生殖。此外，我们还有 初步证据表明，参与内分泌细胞合成和代谢的酶的表达是 受OCP的影响。拟议中的研究将检验一个中心假设，即暴露在大口黑鱼 在阿波普卡湖地区发现的有机氯农药浓度会因性别而扰乱内分泌系统功能 激素受体介导和性激素受体非依赖性机制。在这项提案中，我们有 从生物水平设计了一系列相互关联的实验，其中有机氯农药的多效性效应可以 被测量到细胞水平，在那里可以评估特定的分子作用机制。我们是 暴露于甲氧氯胺(及其代谢物)、p，p‘DDE、狄氏剂和毒杀芬。我们的 具体目标包括1：开发体内暴露于有机氯农药的生物标记物，通过使用 微阵列和新的蛋白质组学方法；2：确定体内接触OCP对LME的影响 类固醇的合成和代谢；以及3：评估有机氯农药对血管紧张素转换酶分子机制的影响 三种雌激素受体的作用。我们计划使用与已知模式的化合物的接触 行动作为对照，以确定我们将针对的特定基因表达模式的行动模式 比较有机氯农药诱导的基因表达变化的模式。我们将检查这些图案 针对生殖终点的变化，包括卵子成熟的能力(生发泡破裂) 和精子功能(精子活力)。鱼作为环境质量的哨兵很有用，而且是完美的 监测超级基金站点中污染物对生殖的不利影响的模型。通过 外推鱼类可以报告有机氯农药对人类健康的潜在危害。