ENVIRONMENTAL ULTRAVIOLET LIGHT AND CYTOSKELETAL DAMAGE

因为太阳紫外线(UV)是皮肤的主要原因 癌症，识别紫外线引起的细胞损伤是很重要的 这可能在致癌过程中起作用。除了……之外 追寻DNA损伤的作用，紫外线诱导的重要性 其他细胞成分的改变也必须考虑在内。 目前这项研究的目的是调查 培养细胞暴露于辐射引起的细胞骨架 与环境有关的紫外线波长。这个 细胞骨架被选中进行研究，因为它是一种 正常细胞生长调控的重要参与者，以及 破坏这种复杂的细胞质结构可能会导致 有害的细胞功能障碍。 正常人皮肤成纤维细胞和表皮角质形成细胞 在不同的生长条件下培养的菌株将被利用 紫外光诱导的细胞酮变化的表征 微管、微丝和中间丝。 多色紫外光照射下细胞的细胞骨架 由与环境相关的波长组成或更多 学习常用的短波(254 Nm)紫外光 通过荧光显微镜观察。角质形成细胞的细胞骨架 它们已经在不同的阶段接受了紫外线照射 我们还将考察它们之间的区别。此外， 干皮病患者成纤维细胞的细胞骨架 色素沉着症、布卢姆综合征和柯凯恩综合征 进行调查，以确定细胞骨架损伤是否可能 有助于提高细胞的光敏性。在确定了 长波紫外光破坏正常人体的微管 细胞，将进行实验以区分 微管损伤引起的微管断裂 在照射前组装或在未组装的情况下改变 二聚体微管蛋白亚基。这将通过检查以下内容来实现 紫外光对提取细胞骨架的影响及研究 微管蛋白在只含有微管蛋白的细胞中的再聚合 照射时微管蛋白的二聚体形式。的作用 细胞骨架改变形成过程中的活性氧物种 也将进行探索。此外，从紫外线中提取的微管蛋白 用十二烷基硫酸钠对照射细胞和对照细胞进行检查 用聚丙烯酰胺凝胶电泳法测定紫外线 光诱导形成高分子量的交联物 微管蛋白。

Since solar ultraviolet (UV) light is the major cause of skin cancer, it is important to identify the UV induced cellular lesions which may contribute to the carcinogenic process. In addition to pursuing the role of DNA damage, the importance of UV induced alterations of other cellular components must also be considered. It is the aim of the current study to investigate disruption of the cytoskeleton resulting from exposure of cultured cells to environmentally relevant wavelengths of UV light. The cytoskeleton has been selected for investigation since it is an important participant in the regulation of normal cell growth, and disruption of this complex cytoplasmic structure may result in detrimental cellular dysfunctions. Normal human skin fibroblast and epidermal keratinocyte cell strains, cultured under varying growth conditions, will be utilized to characterize UV light induced alterations of cytosketetal microtubules, microfilaments and intermediate filaments. Cytoskeletons of cells exposed to polychromatic UV light composed of environmentally relevant wavelengths or to the more commonly used short wavelength (254 nm) UV light will be studied by fluorescence microscopy. The cytoskeleton of keratinocytes which have been UV irradiated at different stages of differentiation will also be examined. In addition, the cytoskeleton of fibroblasts derived from patients with xeroderma pigmentosum, Bloom's syndrome and Cockayne's syndrome will be investigated in order to determine if cytoskeletal damage may contribute to the photosensitivity of cells. Having determined that long wavelength UV light disrupts microtubules in normal cells, experiments will be performed to differentiate between the disruption of microtubules resulting from damage to microtubules assembled prior to irradiation or from changes in unassembled dimeric tubulin subunits. This will be accomplished by examining the effect of UV light on extracted cytoskeletons and by studying the repolymerization of tubulin in cells which contain only the dimeric form of tubulin at the time of irradiation. The role of reactive oxygen species in the formation of altered cytoskeletons will also be explored. Furthermore, tubulin extracted from UV irradiated and control cells will be examined using SDS polyacrylamide gel electrophoresis in order to determine if UV light induces the formation of high molecular weight, cross-linked tubulin.