Effects of Lead on Calcium-Binding Proteins in Rats

描述（由申请人提供）：拟议研究的主要长期目标是[1]测试铅与C2和膜联蛋白家族的钙结合蛋白相互作用的假设，[2]鉴定大鼠铅暴露后这些钙结合家族的基因和蛋白质。铅中毒在美国仍然是一个普遍的问题，影响了至少5%的儿童。本研究旨在阐明铅毒性的分子机制。先前的研究已经证明铅与C2结构域家族的蛋白质（如蛋白激酶C和突触tagmin）和膜联蛋白之间存在有效的相互作用。此外，铅暴露细胞已被证明可以调节编码钙结合膜联蛋白的基因的表达。本提案的四个具体目标是测量铅与C2结构域和膜联蛋白家族蛋白的相互作用，以确定铅的可能靶点。[2]测定铅暴露大鼠脑、肾、肝基因表达。这种体内模型可能揭示铅暴露是否会差异调节编码钙结合蛋白的基因表达。[3]将基因表达研究扩展到具有良好特征的细胞系（星形胶质细胞、PC12细胞、成纤维细胞和正常大鼠肾细胞）。这些研究将补充体内模型的基因表达测量。[4]将基因表达数据存入可公开访问的数据库。总之，这些研究可能揭示哪些钙结合蛋白与铅相互作用，以及哪些编码钙结合蛋白的基因受到铅暴露的调节。

DESCRIPTION (provided by applicant): The major long-term objectives of the proposed research are [1] to test the hypothesis that lead interacts with calcium binding proteins of the C2 and annexin families, and [2] to identify genes and proteins of these calcium-binding families that are regulated following lead exposure of rats. Lead poisoning remains a pervasive problem in the United States, affecting at least 5% of all children. The proposed research is intended to elucidate molecular mechanisms underlying lead toxicity. Previous studies have demonstrated potent interactions between lead and proteins of the C2 domain family (e.g. protein kinase C and synaptotagmin) and annexins. Furthermore, lead exposure of cells has been shown to regulate the expression of genes encoding calcium-binding annexins. The four specific aims of this proposal are [1] to measure the interactions of lead with proteins of the C2 domain and annexin families, in order to determine the possible targets of lead. [2] To measure gene expression in the brain, kidney and liver of lead-exposed rats. This in vivo model may reveal whether lead exposure differentially regulates the expression of genes encoding calcium-binding proteins. [3] To extend gene expression studies to well characterized cell lines (astrocytes, PC12 cells, fibroblasts and normal rat kidney cells). These studies will complement gene expression measurements from the in vivo model. [4] To deposit gene expression data into a publicly accessible database. Together these studies may reveal which calcium binding proteins interact with lead, and which genes encoding calcium-binding proteins are regulated by lead exposure.