UVR-INDUCED DNA DAMAGE AND ANGIOGENIC GROWTH FACTORS

紫外线引起的 DNA 损伤和血管生成因子

• 批准号: 3265705
• 负责人: RONALD D LEY
• 金额: $ 11.78万
• 依托单位: LOVELACE RESPIRATORY RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-05-01 至 1995-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3265705
• 关键词: DNA damage; DNA repair; angiogenesis; angiogenesis factor; cornea disorder; corneal epithelium; endodeoxyribonuclease; gel electrophoresis; genetic library; histopathology; immunocytochemistry; in situ hybridization; lens; northern blottings; nucleic acid probes; opossums; protein biosynthesis; pyrimidine dimers; radiation carcinogen; radiation carcinogenesis; solar radiation; ultraviolet radiation

Skin and eyes are the only organs of the body that are exposed directly to solar ultraviolet radiation (UVR). It has been shown that xeroderma pigmentosum individuals are deficient in DNA repair and have an increased susceptibility to UVR-induced opacification and neovascularization of the cornea and cancer of the anterior eye. The prospect of stratospheric ozone depletion and the accompanying increase in human exposure to UVR makes it imperative that we understand the acute and chronic responses of the mammalian eye to UVR exposure. The marsupial Monodelphis domestica is an experimental animal model uniquely suited for studies on the role of a specific UVR-induced DNA lesion, the pyrimidine dimer, in causing pathological changes in eyes exposed to UVR. As in the epidermis, cells in the corneal epithelium of M. domestica have a high capacity for the photoreactivation (PR) repair of UVR-induced pyrimidine dimers. The light-dependent PR repair pathway has the unique property of repairing only pyrimidine dimers; therefore, if PR decreases the ability of UVR to induce a photobiological response, it is generally accepted that pyrimidine dimers are in some way involved in initiating that response. Chronic UVR exposure of M. domestica induces tumors of the cornea. UVR induces proliferation of corneal stromocytes and endothelial cells which precedes tumor development. It seems reasonable to assume that UVR in some way induces the synthesis or secretion of mitogenic and angiogenic growth factors that act in an autocrine or paracrine manner to stimulate proliferation of corneal stromocytes and endothelial cells. The proposed research will lest the hypothesis that unrepaired pyrimidine dimers in DNA alters the synthesis and/or release of mitogenic and angiogenic growth factors in the UVR-exposed cornea. These early molecular events may result in enhanced susceptibility to UVR-induced cancer. The specific aims are: 1) RNA blotting and standard histological techniques will be used to determine the time course of angiogenic growth factor expression and pathological changes that occur in the chronically-irradiated cornea. PR will be used to define a role for DNA damage in these processes; 2) in situ hybridization and immunohistochemical staining will be used to identify the site of synthesis and/or release of angiogenic growth factors in the chronically irradiated cornea; and, 3) as an extension of studies on DNA repair in corneal epithelium, damage-specific nucleases in conjunction with alkaline gel electrophoresis will be used to measure the excision and photoreactivation repair of UVR-induced pyrimidine dimers in lens epithelial DNA.

皮肤和眼睛是人体唯一直接暴露于 太阳紫外线辐射（UVR）。 已经表明xeroderma 色素个体缺乏DNA修复，增加了 UVR引起的敏感性和新血管形成 前眼的角膜和癌症。 平流层臭氧的前景 耗尽和随之增加的人类暴露于UVR 我们必须了解 哺乳动物眼中的UVR暴露。 袋动物单纤维是家族 实验动物模型独特地适合研究 特异性UVR诱导的DNA病变，嘧啶二聚体，导致 暴露于UVR的眼睛的病理变化。 与表皮一样，细胞中的细胞 M. forefera的角膜上皮具有很高的能力 UVR诱导的嘧啶二聚体的光电反应（PR）修复。 这 光依赖性PR修复途径具有仅修复的独特特性 嘧啶二聚体；因此，如果PR降低UVR诱导的能力 一种光生物学响应，普遍认为嘧啶二聚体 在某种程度上参与了发起这种反应。 慢性UVR暴露于家长诱导角膜的肿瘤。 UVR 诱导角膜间质细胞和内皮细胞的增殖，这些细胞的增殖 先于肿瘤发育。 假设某些UVR似乎是合理的 方式诱导有丝分裂和血管生长的合成或分泌 以自分泌或旁分泌作用以刺激的因素 角膜间质细胞和内皮细胞的增殖。 提议 研究将避免以下假设：DNA中未修复的嘧啶二聚体 改变有丝分裂和血管生长的合成和/或释放 暴露于UVR的因素。 这些早期的分子事件可能会导致 为了增强对UVR诱导的癌症的敏感性。 具体目的是： 1）RNA印迹和标准组织学技术将用于 确定血管生成因子表达和 慢性辐照的角膜中发生的病理变化。 PR 将用于定义在这些过程中DNA损伤的作用； 2）原位 杂交和免疫组织化学染色将用于识别 合成和/或释放血管生长因子的位点 长期辐照的角膜； 3）作为DNA研究的扩展 在角膜上皮上修复，损伤特异性核酸酶与 碱性凝胶电泳将用于测量切除和 UVR诱导的乙酰胺二聚体的光电反应修复 上皮DNA。