Roles of CYP1 & 19 in Fundulus Steroids & PAH Metabolism

描述(申请人提供)：多环芳烃(PAHs)是普遍存在的污染物，是人类健康问题，因为它们与人类癌症和内分泌中断有关。本论文将以异地甲藻为模型生物，研究细胞色素P450 1B和/或细胞色素P19参与苯并(A)芘毒性的分子机制这一中心假说。具体目标是： 1)用体外重组系统评价CYP1B和CYP19s在BaP和雌激素代谢及雌激素合成中的各自作用， 2)确定BaP诱导的CYP1B介导的代谢在多大程度上对遗传毒性起重要作用。目的2.1：在暴露于BaP的成鱼中，将定量研究组织特异性CYP1B表达、有毒代谢物形成、DNA加合物和氧化应激之间的关系。目的2.2：确定卵子或幼虫暴露如何影响细胞色素P1B的表达及相关的毒理学终点。目的2.3：确定暴露于FISH的肿瘤组织中细胞色素P450 1B和细胞色素P19是如何上调的。 3)测量BaP诱导的芳香酶变化与Fundulus生殖或发育成功之间的关系。 目的3.1：确定母亲暴露于苯并(A)苯是否会降低生殖成功率。 目标3.2：确定卵和幼虫暴露是否以及如何改变芳香酶的表达，以及这是否与发育缺陷有关。这些目标的成功完成将提供对这些重要的P450基因及其在多环芳烃作用机制中的作用的更好的分子理解。这项研究将进一步确定Fundulus作为研究多环芳烃相关毒性和开发人类细胞色素P19或细胞色素P1B相关治疗药物的模式生物的效用。

DESCRIPTION (provided by applicant): Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants that are a human health concern because they are implicated in human cancers and endocrine disruption. The fish Fundulus heteroclitus will be used as a model organism to investigate the central hypothesis that CYP1B and/or CYP19 are involved in the molecular mechanisms of benzo(a)pyrene-mediated toxicity. The Specific Aims are to: 1) Assess the respective roles of CYP1B and CYP19s in BaP and estrogen metabolism and estrogen synthesis with in vitro recombinant systems, 2) Determine the extent, to which BaP-induced CYP1 B-mediated metabolism is important in genotoxicity. Aim 2.1: In adult fish following BaP exposure, the relationship between tissue specific CYP1B expression, toxic metabolite formation, DNA adducts and oxidative stress will be quantitated. Aim 2.2: Determine how egg or larval BaP-exposure affects CYP1B expression and associated toxicological endpoints. Aim 2.3: Determine how CYP1B and CYP19 are up-regulated in tumor tissues in exposed fish. 3) Measure the association between BaP-induced changes in aromatase and Fundulus reproductive or developmental success. Aim 3.1: Determine if maternal BaP-exposure decreases reproductive success. Aim 3.2: Determine if and how egg and larval BaP exposures alter aromatase expression and if this is correlated with developmental deficiencies. Successful completion of these Aims will provide a greater molecular understanding of these important P450 genes and their role in the mechanisms of action of PAHs. This research will further define the utility of Fundulus as a model organism for studying PAH-associated toxicities and in the development of human CYP19 or CYP1 B-related therapeutics.