Proteomic determination of arsenical action

描述（由申请人提供）：由As（III）化合物引起的心血管疾病，如高血压、外周血管疾病和缺血性心脏病，具有血管重塑和血管壁中不适当增殖反应的共同成分。亚慢性（ca. 5周）小鼠暴露于饮用水中的低水平砷增强了基质胶植入物的新血管形成，并对心脏血管生成基因表达产生了差异性影响。虽然无机砷的这些影响是已知的，但关于广泛使用的农业有机砷化合物的影响知之甚少。该提案的重点是确定3-硝基-4-羟基苯基胂酸（洛克沙胂）在血管系统中的毒性作用机制。本研究有两个具体目的：1）研究洛克沙胂及其相关芳香族砷化合物在促进血管生成中的作用。这将在一种新的小鼠胚胎干细胞试验中进行测试，该试验测量基质胶中的血管发育。2)利用蛋白质组学方法研究砷及砷制剂对细胞信号蛋白的瞬时作用。我们将使用新的化学标记方法，二维蛋白质分离，和基质辅助激光解吸电离飞行时间质谱（MALDI-TOF-MS），以确定蛋白质，无论是差异表达，后修饰，或直接绑定到砷时，血管平滑肌细胞暴露于低，环境相关水平的砷或洛克沙胂。这些研究将极大地扩展对与砷相关的血管疾病相关的血管细胞信号的生化激活的理解。

DESCRIPTION (provided by applicant): The cardiovascular diseases caused by As(lll)-compounds, such as hypertension, peripheral vascular disease, and ischemic heart disease, share common components of vascular remodeling and inappropriate proliferative responses in the vessel walls. Sub-chronic (ca. 5 weeks) exposures of mice to low levels of arsenic in drinking water enhanced neovascularization of Matrigel implants and differentially affected cardiac angiogenic gene expression. While these effects are known for inorganic arsenic, precious little is known regarding the effects of widely used agricultural organic arsenic compounds. This proposal focuses on defining mechanisms for the toxic effects of 3-nitro-4-hydroxy phenyl arsonic acid (roxarsone) in the vasculature. There are two specific aims of the proposed research: 1) to investigate the role of roxarsone and related aromatic arsenic compounds in promoting angiogenesis. This will be tested in a novel mouse embryonic stem cell assay that measures vessel development in Matrigel. 2) To use a novel proteomic approach to investigate the transient effects of arsenic and arsenicals on cell signaling proteins. We will use new chemical labeling methods, 2-dimensional protein separation, and matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) to identify proteins that are either differentially expressed, post-translationally modified, or directly bound to arsenicals when vascular smooth muscle cells are exposed to low, environmentally relevant levels of arsenic or roxarsone. These studies will greatly expand the understanding of the biochemical activation of vascular cell signaling that is relevant to arsenic-related vascular diseases.