GENOTOXICITY IN HUMAN FETAL BRAIN DERMIS AND KIDNEY

本申请的目的是进一步表征分子 以及在细胞暴露于基因毒素后发生的生物事件 来源于人胎脑(神经胶质细胞和神经细胞)、肾脏的组织 (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损伤和修复的特征将是 作为DNA修饰、器官和细胞类型的函数进行量化 与个体、器官和细胞的敏感性有关。紫外线辐射和 亚硝酸脲将被用来代表直接作用的遗传毒素， 诱导特性良好的块状(嘧啶二聚体)和非块状(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、 和无核苷酸部位)DNA损伤。研究将在下列时间进行 可能，同时使用新鲜的人类胎儿组织和培养的 来自同一标本的细胞。抑制性、饱和性和 修复酶对相关和非相关试剂的诱导性 单独地或与不同的试剂(即，UV，烷化剂， AAAF)在细胞培养中作为剂量和时间的函数进行研究 暴露在基因毒素和细胞周期的特定阶段，例如G1 VS S阶段。个体细胞和器官的敏感性将由 细胞形态和生长率随剂量和时间的变化， 细胞毒性、非锚定生长与核酸和蛋白质 综合。这项续期研究补助金的研究旨在 为遗传毒性的机制提供新的信息和见解 细胞功能与人体器官和细胞类型的关系。从长远来看 这项研究计划的目标是相互关联的分子事件 特异性DNA修饰的遗传毒性DNA损伤和DNA修复 人体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.