OXIDATIVE DNA DAMAGE AND ITS PROCESSING

DNA氧化损伤及其处理

• 批准号: 6097868
• 负责人: VILHELM A. BOHR
• 金额: --
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6097868
• 关键词: DNA damage; DNA repair; cell line; chromatography; deoxyguanosine; free radical oxygen; mitochondrial DNA; oxidative stress; photoactivation; radiation genetics; ultraviolet radiation; xeroderma pigmentosum

Summary of work: Living organisms are constantly exposed to oxidative stress from environmental agents and from endogenous metabolic processes. The resulting oxidative modifications occur in proteins, lipids and DNA. Since proteins and lipids are readily degraded and resyn-thesized, the most significant consequence of the oxidative stress is thought to be the DNA modifications, which can become permanent via the formation of mutations and other types of genomic instability. Many different DNA base changes have been seen following some form of oxidative stress, and these lesions are widely considered as in- stigators for the development of cancer and are also implicated in the process of aging. Several studies have documented that oxidative DNA lesions accumulate with aging, and it appears that the major site of this accumulation is mitochondrial DNA rather than nuclear DNA. The DNA repair mechanisms involved in the removal of oxidative DNA lesions are much more complex than previously considered. They involve base excision repair (BER) pathways and nucleotide excision repair (NER) pathways, and there is cur-rently a great deal of interest in clarification of the pathways and their interactions. We have used a number of different approaches to explore the mechanism of the repair pro- cesses, and we are able to examine the repair of different types of lesions and to meas-ure different steps of the repair processes. Furthermore, we can measure the DNA damage processing in the nuclear DNA and separately, in the mitochondrial DNA. Contrary to widely held notions, mitochondria have efficient DNA repair of oxidative DNA damage and we are exploring the mechanisms. In a human disorder, Cockayne syn-drome (CS), characterized by premature aging, there appear to be deficiencies in the repair of oxidative DNA damage in the nuclear DNA, and this may be the major underlying cause of the disease.

工作总结：生物是不断的