Signal transduction in cytoprotective responses

细胞保护反应中的信号转导

• 批准号: 6881609
• 负责人: MIHAIL IORDANOV
• 金额: $ 26.88万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6881609
• 关键词: JUN kinase; NAD(P)H dehydrogenase; antioxidants; biological signal transduction; cytochrome c; cytoprotection; enzyme activity; enzyme induction /repression; enzyme inhibitors; fibroblasts; free radical oxygen; genetic transcription; glutathione transferase; mitochondria; site directed mutagenesis; tissue /cell culture; transfection

DESCRIPTION: (PROVIDED BY APPLICANT) Electrophilic compounds exert cellular toxicity by compromising the redox balance of cells and causing oxidative stress. Relevant examples of such compounds are environmental pollutants such as AS3+ and Cd2+, products of the peroxidation of fatty acids, such as 4-hydroxy-2,3-nonenal, and chemotherapeutic agents, such as doxorubicin. The phase II detoxifying enzymes (a group of conjugating enzymes that includes, among others, glutathione S-transferases and quinone reductases) are the major cellular defense system against toxic environmental and metabolic electrophiles. Investigating the anti-oxidant response of mouse embryonic fibroblasts deficient in the genes encoding the stress-activated protein kinases JNK1 and JNK2, we have found that, like phase II detoxifying enzymes, JNKs are critical for the cytoprotective responses to electrophiles and oxidants. JNK-deficient cells are severely susceptible to oxidative stress and this increased susceptibility correlates with elevated production of reactive oxygen species by JNK-deficient cells and their inability to maintain sufficient levels of several phase II detoxification enzymes (e.g. the glutathione S-transferases of the A, M, and P functional classes) when challenged with electrophiles and oxidants. The research proposed in this grant proposal will elucidate the molecular mechanisms that mediate the regulation of phase II enzyme expression by JNK and the involvement of these JNK-regulated phase II enzymes in the resistance to environmental oxidants and electrophiles. To this end, we will utilize fibroblast cells from mice with genetic inactivation ("knockout") of JNKs and various upstream regulators of JNK activity and we will employ molecular, cellular, and biochemical approaches (such as transfection, inducible expression of transgenic alleles, site-directed mutagenesis, analysis of gene expression at mRNA and protein levels, analysis of post-translational protein modifications, subcellular fractionation, and pharmacological interference with enzyme functions). The proposed research may lead to the development (on the basis of pharmacological effectors of the JNK signaling pathway) of novel strategies for counteracting the harmful pro-oxidant impact of important environmental pollutants.

描述：（由申请人提供）电池化合物施加细胞 毒性通过损害细胞的氧化还原平衡并引起氧化 压力。此类化合物的相关例子是环境污染物 作为AS3+和CD2+，脂肪酸的过氧化产物，例如 4-羟基-2,3-非烯酸和化学治疗剂，例如阿霉素。这 II期解毒酶（一组共轭酶，包括 除其他外，谷胱甘肽S-转移酶和醌还原酶是主要的 针对有毒环境和代谢的细胞防御系统 电力。研究小鼠胚胎的抗氧化反应 成纤维细胞缺乏编码应激激活蛋白的基因 激酶JNK1和JNK2，我们发现，就像II期解毒酶一样， JNK对于对电物质的细胞保护反应至关重要 氧化剂。缺乏JNK的细胞严重易受氧化应激和 这种提高的敏感性与反应性的产生升高有关 JNK缺陷型细胞及其无法维持的氧气物种 足够水平的几种II期解毒酶（例如 A，M和P功能类的谷胱甘肽S-转移酶）当 受到电力和氧化剂的挑战。这项赠款提出的研究 提案将阐明介导调节的分子机制 JNK的II期酶表达和这些JNK调节的参与 对环境氧化剂和电力物的抗性中的II期酶。 为此，我们将利用带有遗传的小鼠的成纤维细胞 JNK和JNK的各种上游调节器的失活（“淘汰”） 活动，我们将采用分子，细胞和生化方法 （例如转染，转基因等位基因的诱导表达， 定点诱变，mRNA和蛋白质基因表达的分析 水平，翻译后蛋白质修饰，亚细胞的分析 分馏和药理学干扰酶功能）。这 拟议的研究可能导致发展（基于药理 JNK信号通路的效应子）的新型策略来抵消 重要的环境污染物的有害促氧化作用。