COX-2 and Injury in the Immature Brain

COX-2 与未成熟大脑损伤

• 批准号: 6360373
• 负责人: ROBERT W HICKEY
• 金额: $ 12.47万
• 依托单位: CHILDREN'S HOSP PITTSBURGH/UPMC HLTH SYS
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6360373
• 关键词: brain injury; cell proliferation; cerebral ischemia /hypoxia; enzyme mechanism; excitatory aminoacid; gene expression; gene targeting; genetic regulation; genetically modified animals; laboratory mouse; laboratory rat; nitric oxide synthase; peroxynitrites; prostaglandin endoperoxide synthase; protein isoforms; synapses; tissue /cell culture

DESCRIPTION (provided by applicant): There is a transient period of increased sensitivity to hypoxic-ischemic and excitatory amino acid (EAA)-mediated brain injury that parallels the development of synaptic connectivity and EAA-receptor maturation in developing brain. In rodents, this period of increased sensitivity to brain injury occurs between 1-3 wk following birth. The inducible isoform of cyclooxygenase (COX-2) is developmentally regulated gene that is induced by synaptic activity and down-regulated by EAA antagonists. Thus, neuronal COX-2 production is greatest during the period of maximal synaptic proliferation coinciding with the period of increased vulnerability to hypoxic-ischemic and excitotoxic brain injury that occurs from 1-3 wk following birth. Recently, COX-2 has been identified as contributing to the development of ischemic brain injury in mature rodents. These observations suggest that COX-2 may be an unrecognized mediator of developmentally regulated susceptibility to hypoxic-ischemic and excitotoxic brain injury in immature brain. The ability of hypoxia-ischemia and EAA toxicity to induce COX-2 expression in the developing brain and the effect of COX-2 inhibition upon injury to the developing brain has not been investigated. Accordingly, The candidate proposes to test the hypothesis the induction of COX-2 exacerbates hypoxic-ischemic and EAA-mediated injury in the developing brain. In addition, the candidate will use tissue culture and gene knock-out technology to investigate a potential mechanism of COX-2 toxicity. Namely, he will investigate the possibility that COX-2 and nitric oxide synthase (NOS) synergistically contribute to the formation of the highly toxic reactive oxygen species peroxynitrite. This is an attractive line of inquiry because neuronal NOS is a developmentally regulated gene with temporal profile of expression mirroring COX-2 expression and because it will expose the candidate to experiments using tissue culture and gene knock-out technology. The candidate s long-term objective is to develop into an independent clinician scientist with a complete battery of research skills and the capability of mentoring other clinician scientists. A Mentored Clinical Scientist Development Award will allow continued access to excellent mentorship and will increase the time available for attaining new research skills. The proposed experiments take advantage of on-campus expertise with two molecules of significant scientific interest - COX and NOS. The proposed experiments provide the candidate with access to a rich variety of contemporary molecule biology tools that will promote his development as a clinician scientist in Pediatric Emergency Medicine while facilitating an in depth examination of the mechanisms involved in COX-2 neurotoxicity. Understanding these mechanisms is of potential clinical importance because treatments that are commonly used in critically injured infants and children (e.g., NSAIDS, steroids, etc.) can influence COX-2 production and isoform-specific COX-2 inhibitors have recently become clinically available.

描述（由申请人提供）：有一个暂时性的增加 对低氧缺血和兴奋性氨基酸（EAA）介导的大脑的敏感性 与突触连通性发展的伤害和 EAA受体成熟在发育中的大脑中。 在啮齿动物中，这个时期 对脑损伤的敏感性提高发生在出生后的1-3周之间。 环氧酶（COX-2）的诱导同工型受发展调节 由突触活性诱导并由EAA下调的基因 对手。 因此，神经元COX-2的产生最大 最大突触增殖与增加的周期一致 发生低氧缺血性和兴奋性脑损伤的脆弱性 出生后1-3周。 最近，COX-2已被确定为 有助于成熟啮齿动物中缺血性脑损伤的发展。 这些观察结果表明，COX-2可能是未识别的调解人 发育调节对低氧缺血和兴奋性毒性的敏感性 未成熟大脑的脑损伤。 缺氧 - 疾病和EAA的能力 在发育中诱导COX-2表达的毒性和 COX-2抑制发育大脑受伤的尚未 调查。 因此，候选人提议检验假设 COX-2的诱导加剧了低氧 - 缺血性和EAA介导的损伤 发展大脑。 此外，候选人将使用组织培养和基因 敲除技术研究COX-2毒性的潜在机制。 也就是说，他将研究COX-2和一氧化氮的可能性 合成酶（NOS）协同有助于形成高度毒性 活性氧过氧亚硝酸盐。 这是一条吸引人的询问线 因为神经元NOS是具有时间谱的发育调节基因 表达式镜像Cox-2表达，因为它将暴露 使用组织培养和基因敲除技术进行实验的候选者。 候选人的长期目标是发展成为独立的 具有完整的研究技能的临床医生和 指导其他临床医生的能力。 一个受过指导的临床 科学家发展奖将允许继续获得优秀 指导，并将增加获得新研究的时间 技能。 提出的实验利用了校园内专业知识 具有重大科学兴趣的两个分子-COX和NOS。 提议 实验为候选人提供了各种各样的访问 当代分子生物学工具将促进他作为一个 小儿急诊医学的临床医生，同时促进 对COX-2神经毒性涉及的机制的深度检查。 了解这些机制具有潜在的临床重要性，因为 通常用于重伤的婴儿和儿童的治疗 （例如，NSAID，类固醇等）可以影响COX-2的产生和 同工型特异性COX-2抑制剂最近已在临床上可用。