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.

皮肤和眼睛是身体唯一直接暴露于环境的器官 太阳紫外线辐射（UVR）。 研究表明，干皮病 色素体个体缺乏 DNA 修复，并且具有增加的 DNA 修复能力。 对 UVR 引起的混浊和新生血管的敏感性 角膜和前眼癌。 平流层臭氧的前景 消耗以及随之而来的人类暴露于紫外线的增加使得 我们必须了解急性和慢性反应 哺乳动物眼睛对紫外线的暴露。 有袋动物 Monodelphis Domestica 是一种 实验动物模型特别适合研究a的作用 特定的 UVR 诱导的 DNA 损伤（嘧啶二聚体） 暴露于 UVR 的眼睛发生病理变化。 与表皮一样，细胞 家蝇的角膜上皮具有很高的能力 UVR诱导的嘧啶二聚体的光再激活（PR）修复。 这 光依赖性PR修复途径具有仅修复的独特性质 嘧啶二聚体；因此，如果 PR 降低了 UVR 诱导的能力 光生物学反应，人们普遍认为嘧啶二聚体 以某种方式参与发起该响应。 家蝇的长期紫外线照射会诱发角膜肿瘤。 紫外线辐射 诱导角膜基质细胞和内皮细胞增殖， 先于肿瘤发展。 假设 UVR 在某些情况下似乎是合理的 方式诱导有丝分裂和血管生成的合成或分泌 以自分泌或旁分泌方式发挥作用的因子 角膜基质细胞和内皮细胞的增殖。 拟议的 研究将避免DNA中未修复的嘧啶二聚体的假设 改变促有丝分裂和血管生成生长的合成和/或释放 暴露于 UVR 的角膜的因素。 这些早期分子事件可能会导致 增加对紫外线诱发的癌症的易感性。 具体目标是： 1) RNA印迹和标准组织学技术将用于 确定血管生成生长因子表达的时间过程和 长期受照射的角膜发生的病理变化。 公关 将用于定义 DNA 损伤在这些过程中的作用； 2）原位 杂交和免疫组织化学染色将用于鉴定 血管生成生长因子的合成和/或释放位点 长期受照射的角膜； 3) 作为 DNA 研究的延伸 修复角膜上皮，损伤特异性核酸酶与 碱性凝胶电泳将用于测量切除和 UVR诱导的晶状体嘧啶二聚体的光活化修复 上皮DNA。