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: 8443233
• 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/8443233
• 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暴露于环境毒物如何导致成年后的疾病。同样重要的是，要确定一次早期有毒物质接触是否会影响后代的健康。了解和识别这些风险将对人类健康产生积极影响。我的研究重点是使用斑马鱼了解在发育过程中暴露于2，3，7，8四氯二苯并对二恶英（TCDD，二恶英）的成年人中观察到的两种毒性反应，在万亿分之一（ppt）水平。我们发表的工作和我的初步结果表明，在发育过程中的单次暴露可导致骨骼畸形和生殖毒性的成年人，并在随后的F1和F2代的各种形式的毒性。F0成体毒性包括明显的雄性雌性化，其中具有雌性第二性征的鱼具有睾丸。目标是确定TCDD是否改变性腺命运，将卵巢变为睾丸，或使男性身体女性化。毒性的另一个主要迹象是， 成年人在早期发育过程中暴露的是类似于人类脊柱侧凸的中轴骨骼畸形。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，从而确定骨骼发育中这些变化的来源。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特化的主要调节因子：sox9被认为是男性Y染色体sry基因的靶基因。我还观察到sox9b在斑马鱼脊椎发育部位的表达。因此，我将研究人类sox9的斑马鱼同源物：sox9a和sox9b在发育中的骨和性腺的TCDD处理的斑马鱼的表达。我发现暴露于F0鱼的F1和F2后代具有可重复的毒性， 只是在发展过程中短暂地。我将更好地描述这种跨代毒性，测量每一代受影响组织中整体基因表达的变化，并将使用基因特异性和整体技术来检查TCDD暴露诱导的DNA甲基化和染色质结构的改变，并传递到F1和F2鱼。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，申请R21或R03资助。跨代的研究，即使是在斑马鱼身上，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拨款专注于推动我的结果的机制。作为K01获奖者，我将遵循职业发展计划，每个获奖年度都有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，以加强我将转化和机械研究联系起来的能力。我将获得成功的职业生涯所需的领域在转化研究，包括项目规划，手稿和赠款写作，并确定和掌握所需的细胞和分子技术，以推动我的研究。我有一个临床背景与研究重点。我将获得经验，在机械，假设检验驱动的研究。这项计划将扩展我的研究专长，并加强我在发育毒理学研究方面的培训。威斯康星州的大学有许多NIH赞助的培训项目，核心设施和资助的研究人员，使它成为一个理想的培训环境，我发展为一个独立的科学家。