SIGNAL TRANSDUCTION MECHANISMS AND LEAD TOXICITY

信号转导机制和铅毒性

• 批准号: 6382215
• 负责人: JOSEPH paul BRESSLER
• 金额: $ 20.16万
• 依托单位: HUGO W. MOSER RES INST KENNEDY KRIEGER
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6382215
• 关键词: biological signal transduction; environmental toxicology; enzyme activity; erythrocyte membrane; erythrocytes; human tissue; laboratory rat; lead poisoning; membrane proteins; phosphorylation; protein kinase C; tissue /cell culture

DESCRIPTION: (Adapted from the Investigator's Abstract) Lead toxicity has been identified as the most important environmental health hazard affecting children in the United States, but the mechanism for this toxicity is unknown. Several studies have established that protein kinase C (PKC) is exquisitely sensitive to Pb2+, thereby suggesting that this kinase plays a pivotal role in Pb2+-mediated toxicity. Previous work in this area, however, has focused on the effects of Pb2+ on PKC in enzymatic assays and on its cellular localization. Studies have not addressed the effects of Pb2+ on PKC activity or on protein phosphorylation in cultured cells or in vivo. In order to study this problem, erythrocytes will be examined because they are a target for Pb2+, proteins phosphorylated by PKC have been described, and they are more accessible in studies in vivo than other tissues. The first long term goal of this study is to determine whether Pb2+ stimulates phosphorylation of erythrocyte membrane proteins by activating PKC. This will be accomplished in Aim 1 by a definitive immunological and biochemical analysis of membrane phosphoproteins from human erythrocytes that were exposed in vitro to Pb2+. In addition, the mechanism of activation will be elucidated by examining the physical interaction that occurs between Pb2+ and PKC. The second long term goal is to determine whether exposure to Pb2+ in vivo increases erythrocyte membrane protein phosphorylation. For this purpose, information gained from the in vitro system will be used in Aim 2 to study protein phosphorylation in erythrocytes isolated from Pb2+-exposed rats. Ultimately, a protein that is phosphorylated in rats with elevated levels of Pb2+ may provide a biomarker to monitor Pb2+.

描述：（改编自研究者的摘要）铅毒性已 被确定为影响最重要的环境健康危害 美国的儿童，但这种毒性的机制是 未知。 多项研究已证实蛋白激酶 C (PKC) 对 Pb2+ 极其敏感，因此表明该激酶起着 在 Pb2+ 介导的毒性中发挥关键作用。 之前在该领域的工作， 然而，重点关注酶测定中 Pb2+ 对 PKC 的影响， 关于其细胞定位。 研究尚未解决其影响 Pb2+ 对培养细胞或细胞中 PKC 活性或蛋白质磷酸化的影响 体内。 为了研究这个问题，将检查红细胞，因为 它们是 Pb2+ 的目标，被 PKC 磷酸化的蛋白质已被 描述，并且它们在体内研究中比其他方法更容易获得 组织。 这项研究的第一个长期目标是确定是否 Pb2+通过以下方式刺激红细胞膜蛋白的磷酸化 激活 PKC。 这将通过明确的目标 1 来实现 膜磷蛋白的免疫学和生化分析 体外暴露于 Pb2+ 的人类红细胞。 此外， 激活机制将通过检查物理来阐明 Pb2+ 和 PKC 之间发生的相互作用。 第二个长期目标是 确定体内暴露于 Pb2+ 是否会增加红细胞膜 蛋白质磷酸化。 为此，从内部获得的信息 目标 2 将使用体外系统来研究蛋白质磷酸化 从暴露于 Pb2+ 的大鼠中分离出的红细胞。 最终，一种蛋白质是 Pb2+ 水平升高的大鼠中磷酸化可能提供生物标志物 监测 Pb2+。