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: 8685364
• 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 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8685364
• 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; public health relevance; 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期和儿童期接触环境毒物如何导致成年后患病。确定单一的早期有毒物质暴露是否会影响后代的健康也至关重要。了解和识别这些风险将对人类健康产生积极影响。我的研究重点是利用斑马鱼了解在发育过程中暴露于万亿分之一 (ppt) 水平的 2,3,7,8 四氯二苯并二恶英（TCDD，二恶英）的成年人中观察到的两种毒性反应。我们发表的工作和我的初步结果表明，发育过程中的单次暴露可导致成虫骨骼畸形和生殖毒性，以及随后的 F1 和 F2 代中各种形式的毒性。 F0 成鱼毒性包括明显的雄性女性化，其中具有女性第二性征的鱼有睾丸。目标是确定 TCDD 是否会改变性腺命运，将卵巢改变为睾丸，或使男性身体女性化。毒性的另一个主要迹象 成年人在早期发育过程中暴露出的中轴骨骼畸形类似于人类脊柱侧弯。我将通过染色和测量基因表达的变化来检查骨骼和胶原蛋白，以确定骨骼发育中这些变化的根源。 sox9b 基因的下调是 TCDD 诱导斑马鱼颌骨畸形的原因。人类 sox9 基因是骨骼形成和性别规范的主要调节因子：sox9 被认为是男性 Y 染色体 sry 基因的目标。我还在斑马鱼的椎骨发育部位观察到了 sox9b 的表达。因此，我将检查人类 sox9 斑马鱼同源物：sox9a 和 sox9b 在 TCDD 处理的斑马鱼发育中的骨骼和性腺中的表达。我发现暴露的 F0 鱼的 F1 和 F2 后代具有可重复的毒性 仅在开发过程中短暂存在。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局基因表达的变化，并将使用基因特异性和全局技术来检查 TCDD 暴露引起的 DNA 甲基化和染色质结构的变化，并传播到 F1 和 F2 鱼中。在这个项目的第三年，我计划使用这项工作的结果作为初步数据来申请 R21 或 R03 补助金。跨代工作，即使是在斑马鱼中，也需要几年的时间才能成熟，因此拟议的工作将允许未来的资助重点关注驱动我的结果的机制。作为 K01 获奖者，我将遵循职业发展计划，为每个获奖年度制定非常具体的研发里程碑。我将定期与我的导师和咨询委员会会面，以加强我将转化研究和机械研究联系起来的能力。我将获得转化研究成功所需领域的体验式培训，包括项目规划、手稿和拨款写作，以及推动我的研究前进所需的细胞和分子技术的识别和掌握。我有以研究为重点的临床背景。我将获得机械的、假设检验驱动的研究经验。该计划将扩展我的研究专业知识并加强我在发育毒理学研究方面的培训。威斯康星大学拥有众多由 NIH 资助的培训项目、核心设施和资助的研究人员，这使其成为我发展成为一名独立科学家的理想培训环境。