GENOTOXICITY IN HUMAN FETAL BRAIN DERMIS AND KIDNEY

本申请的目的是进一步表征分子结构。 和细胞暴露于遗传毒素后发生的生物学事件， 来源于人胎脑的组织（神经胶质细胞和神经元细胞）、肾 （近端肾小管和肾小球上皮细胞）和皮肤（成纤维细胞 和上皮细胞）。 DNA损伤和修复将被表征， 作为DNA修饰、器官和细胞类型的函数进行定量， 与个体、器官和细胞的敏感性有关。 UV辐射和 亚硝基脲将用于代表直接作用的遗传毒素， 诱导良好表征大体积（嘧啶二聚体）和非大体积（N7和 06-烷基鸟嘌呤，04和02-烷基胸腺嘧啶，N3-烷基腺嘌呤，磷酸三酯， 和脱嘌呤位点）损伤。 将进行研究， 可能的，同时与新鲜的人胎儿组织和培养的 来自同一标本的细胞。 抑制性、饱和性和 相关和不相关试剂对修复酶的诱导性 单独地或与不同试剂组合（即，UV，烷基化剂， AAAF）将在细胞培养中作为剂量和时间的函数进行研究 暴露于遗传毒素和细胞周期的特定阶段，例如G1 与S期比较。 单个细胞和器官的敏感性将通过 细胞形态和生长速率的剂量和时间依赖性变化， 细胞毒性、锚定非依赖性生长以及核酸和蛋白质 合成. 这项更新研究补助金的研究旨在 提供了新的信息和见解的遗传毒性的机制， 与人体器官和细胞类型有关的细胞功能。 长期 这项研究计划的目标是相互关联的分子事件， 遗传毒性DNA损伤和DNA修复的特定DNA修饰， 人体内和体外的生物学参数。

The objective of this application is to further characterize the molecular and biological events that occur following genotoxin exposure of cells and tissues derived from human fetal brain (glial and neuronal cells), kidney (proximal tubular and glomerular epithelial cells), and skin (fibroblastic and epithelial cells). DNA damage and repair will be characterized and quantitated as a function of DNA modification, organ and cell type as related to individual, organ and cell sensitivity. UV radiation and nitrosoureas will be used to represent direct acting genotoxins which induce well characterized bulky (pyrimidine dimers) and non-bulky (N7 and 06-alkylguaine, 04 and 02-alkylthymine, N3-alkyladenine, phhosphotriester, and apurinic sites) lesions in the DNA. Studies will be done, when possible, simultaneously with both fresh human fetal tissue and cultured cells derived from the same specimen. The inhibition, saturability and inducibility of the repair enzymes with related and unrelated agents either separately or in combination with different agents (i.e., UV, alkylator, AAAF) will be investigated in cell culture as a function of dose and time of exposure to genotoxin and in specific stages of the cell cycle, e.g. G1 vs S phase. Indiviudal cell and organ sensitivity will be measured by the dose and time dependent changes in cell morphology and growth rate, cytotoxicity, anchorage independent growth and nucleic acid and protein synthesis. The studies of this renewal research grant are designed to provide new information and insights into the mechanisms of genotoxicity on cellular function in relation to human organ and cell type. The long term goal of this research program is to interrelate the molecular events of genotoxic DNA damage and DNA repair of specific DNA modifications to the biological parameters in humans in vivo and in vitro.