Adult and Transgenerational Toxicity Due to Developmental TCDD Exposure

发育期接触 TCDD 导致的成人和跨代毒性

• 批准号: 8827435
• 负责人: Tracie R Baker
• 金额: $ 13.15万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8827435
• 关键词: ARNT gene; Adult; Adverse effects; Advisory Committees; Affect; Agonist; Area; Aryl Hydrocarbon Receptor; Automobile Driving; Award; Biological Models; Chemicals; Childhood; Chromatin; Chromatin Structure; Clinical; Collagen; Core Facility; DNA Methylation; Data; Defect; Deformity; Development; Development Plans; Dioxins; Disease; Down-Regulation; Environment; Epigenetic Process; Exposure to; Female; Feminization; Fertilization; Fetal Development; Fishes; Funding; Future; Gene Expression; Generations; Genes; Germ Cells; Goals; Gonadal structure; Grant; Health; Histology; Homologous Gene; Human; In Situ Hybridization; Incidence; Jaw; Link; Magnetic Resonance Imaging; Manuscripts; Measures; Mentors; Methods; Molecular; Morphology; Ovary; Parents; Pathology; Population; Pregnancy; Public Health; Publishing; Reporter; Research; Research Personnel; Risk; Scientist; Sex Characteristics; Sex Ratio; Shapes; Site; Skeletal Development; Skeleton; Source; Spinal; Staging; Staining method; Stains; Stretching; Techniques; Testing; Testis; Tetrachlorodibenzodioxin; Tissues; Toxic Environmental Substances; Toxic effect; Toxicant exposure; Training; Training Programs; Transcript; Transgenic Organisms; Translational Research; United States National Institutes of Health; Universities; Vertebral column; Wisconsin; Work; Writing; Y Chromosome; Zebrafish; base; body system; bone; career; career development; developmental toxicology; experience; histone modification; improved; male; malformation; meetings; offspring; reproductive; research and development; response; scoliosis; sex; skeletal; skeletal abnormality; spine bone structure; sry Genes; transcriptome sequencing

DESCRIPTION (provided by applicant): An important goal in improving human health is to understand how exposure to environmental toxicants during gestation and childhood leads to disease later in adulthood. It is also vital to determine whether a single early toxicant exposure can affect the health of subsequent generations. Understanding and identifying these risks will positively impact human health. My research focus is to use zebrafish to understand two toxic responses seen in adults exposed during development to 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD, dioxin), at the parts per trillion (ppt) level. Our published work and my preliminary results indicate that a single exposure during development can cause skeletal malformation and reproductive toxicity in the adults, and various forms of toxicity in the subsequent F1 and F2 generations. F0 adult toxicity includes an apparent male feminization in which fish with female secondary sex characteristics have testes. A goal is to determine whether TCDD alters gonadal fate, changing ovaries to testes, or feminizes the body of males. Another major sign of toxicity in adults exposed during early development is malformations in the axial skeleton resembling human scoliosis. I will identify the source of these changes in skeletal development examining bone and collagen by staining and measuring alterations in gene expression. Down-regulation of the sox9b gene is the cause of TCDD-induced jaw malformation in zebrafish. The human sox9 gene is a master regulator of both skeletal formation and sex specification: sox9 is thought to be the target of the male Y-chromosome sry gene. I have also observed sox9b expression at the site of vertebral development in zebrafish. Therefore, I will examine the expression of both zebrafish homologs of human sox9: sox9a and sox9b in developing bone and gonad of TCDD-treated zebrafish. I find reproducible toxicity in F1 and F2 offspring of F0 fish that were exposed only briefly during development. I will better characterize this transgenerational toxicity, measuring changes in global gene expression in affected tissues from each generation and will use both gene- specific and global techniques to examine alterations in DNA methylation and chromatin structure induced by TCDD exposure and transmitted into F1 and F2 fish. In year 3 of this project, I plan to use the results from this work as preliminary data to apply for an R21 or R03 grant. Transgenerational work, even in zebrafish, takes several years to mature, so the proposed work would allow a future grant to focus on mechanisms driving my results. As a K01 recipient, I will follow a career development plan with very specific research and development milestones for each award year. I will meet regularly with my mentors and advisory committee to strengthen my ability to link translational and mechanistic research. I will obtain experiential training in areas needed for a successful career in translational research, including project planning, manuscript and grant writing, and identification and mastery of cellular and molecular techniques needed to move my research forward. I have a clinical background with a research emphasis. I will gain experience in mechanistic, hypothesis testing driven research. This plan will stretch my research expertise and enhance my training in developmental toxicology research. The University of Wisconsin has numerous NIH-sponsored training programs, core facilities and funded researchers making it an ideal training environment for me to develop as an independent scientist.

描述（由申请人提供）：改善人类健康的一个重要目标是了解妊娠和儿童期间对环境有毒物质的暴露如何导致成年后期的疾病。确定单一的早期毒物暴露是否会影响后代的健康也至关重要。理解和识别这些风险将对人类健康产生积极影响。我的研究重点是使用斑马鱼在发育过程中暴露于2,3,7,8四氯迪本佐-P-二恶英（TCDD，二恶英）的两种有毒反应，分别为每百万（PPT）。我们发表的工作和我的初步结果表明，发育过程中的单一暴露会导致成人的骨骼畸形和生殖毒性，以及随后的F1和F2世代的各种形式的毒性。 F0成人毒性包括明显的男性女性化，其中具有女性次要性特征的鱼具有睾丸。一个目标是确定TCDD是否改变了性腺命运，将卵巢变化为睾丸或使雄性身体女性化。毒性的另一个主要迹象 早期发育过程中暴露的成年人是类似人脊柱侧弯的轴向骨骼的畸形。我将通过染色和测量基因表达的改变来确定骨骼发育中这些变化的来源。 Sox9b基因的下调是斑马鱼中TCDD诱导的下颌畸形的原因。人类SOX9基因是骨骼形成和性别规格的主要调节因子：Sox9被认为是雄性Y-chromosoms sry基因的靶标。我还观察到斑马鱼椎骨发育部位的Sox9b表达。因此，我将研究人类Sox9：Sox9a和Sox9b的斑马鱼同源物在发育中TCDD处理的斑马鱼的骨和性腺中的表达。我发现在暴露的F0鱼的F1和F2后代可再现的毒性 仅在开发过程中短暂。我将更好地表征这种跨代毒性，测量每一代受影响组织中全球基因表达的变化，并将使用基因和全球技术来检查DNA甲基化和TCDD暴露诱导的染色质结构的改变，并传播到F1和F2鱼中。在该项目的第3年中，我计划将这项工作的结果用作初步数据，以申请R21或R03赠款。跨代工作，即使在斑马鱼，也需要数年才能成熟，因此拟议的工作将使未来的赠款专注于推动我结果的机制。作为K01接收者，我将遵循一个职业发展计划，每个奖励年度都具有非常具体的研发里程碑。我将定期与导师和咨询委员会会面，以增强我将翻译和机械研究联系起来的能力。我将在转化研究中成功的领域获得体验培训，包括项目计划，手稿和赠款写作，以及识别和精通蜂窝和分子技术，以推动我的研究前进。我有一个临床背景，重点是研究。我将获得机械，假设测试驱动的研究的经验。该计划将扩大我的研究专业知识，并增强我在发育毒理学研究方面的培训。威斯康星大学拥有许多NIH赞助的培训计划，核心设施和资助的研究人员，使其成为我作为独立科学家发展的理想培训环境。