Mitochondrial oxidative stress: a target for treatment of doxorubicin-associated vascular endothelial dysfunction

项目摘要/摘要 这份F32申请的目的是为了支持扎卡里·克莱顿博士，他是一名有前途的第一年博士后 在道格拉斯·海尔斯博士的实验室里，进行原创研究和科学培训，这将 让他做好准备，成为一名独立的、由外界资助的翻译领域的调查员 心血管生理学旨在预防心血管疾病(CVD)。克莱顿博士将学到一种 各种新的技术、概念和专业技能，包括有重点的翻译培训 小鼠的临床前血管生理学研究。他提出的研究项目寻求(目标1)调查 最常用的蒽环类药物阿霉素(Doxo)的作用机制(S) 药物介导血管内皮细胞功能障碍，这是心血管疾病发展过程中的关键病理生理步骤。 他还将确定(目标2)是否有一种针对线粒体的翻译抗氧化剂疗法--米托喹酚 甲磺酸(MitoQ®)可恢复Doxo所致的幼年成年小鼠血管内皮功能障碍 治疗后不久；和b)中年小鼠(在青春期用多索多索治疗)对 接受DOXO治疗的中年儿童癌症幸存者。血管内皮细胞功能障碍通常由 内皮衍生扩张剂分子一氧化氮(NO)的生物利用度因过量而降低 产生超氧化物，它与NO反应。功能失调的线粒体是整体 超氧化物的产生，部分原因是抗氧化剂防御能力的补偿性增加不足。Doxo有 已有报道可降低血管内皮功能，但其潜在的机制和 治疗策略目前尚不清楚。在强劲的初步数据的指导下，克莱顿博士将进行调查 用体外“药物解剖”的方法探讨DOXO介导内皮功能障碍的机制(S) 技术，特别侧重于线粒体超氧化物在降低NO生物利用度中的作用(目的 1)。此外，克莱顿博士将寻求建立初步的(临床前)概念证明证据 补充线粒体特异性抗氧化剂MitoQ可以减轻Doxo诱导的内皮细胞 功能障碍(目标2)。总体而言，拟议的研究有可能解决2个重要的战略问题 NHLBI的研究重点：1)确定降低血管发病率和死亡率的最佳战略 儿童癌症幸存者的血管事件风险增加；2)确定治疗目标， 建立概念证明，并为研究新药应用开发数据，以使早期 将研究成果转化为临床应用。赞助商，海尔斯博士，是国际公认的 NIH资助的科学家在翻译生物医学研究方面有着成功的指导历史。 在他的指导下，以及咨询导师安东尼·多纳托、迈克尔·墨菲和朱迪思博士的指导下 坎皮西，克莱顿博士将能够顺利完成拟议的研究和培训计划，准备 他成功地成为了一名在翻译心血管生理学领域由外界资助的独立研究员。

PROJECT SUMMARY/ABSTRACT The purpose of this F32 application is to support Dr. Zachary Clayton, a promising first-year postdoctoral fellow in the laboratory of Dr. Douglas Seals, to conduct original research and scientific training that will prepare him to become an independent, extramurally-funded investigator in the field of translational cardiovascular physiology aimed at the prevention of cardiovascular diseases (CVD). Dr. Clayton will learn a variety of new technical, conceptual and professional skills, including focused training in translational preclinical vascular physiology research in mice. His proposed research project seeks to (Aim 1) investigate the mechanism(s) by which doxorubicin (DOXO), the most commonly used anthracycline-chemotherapy drug, mediates vascular endothelial dysfunction, a key pathophysiological step in the development of CVD. He also will determine (Aim 2) if a translational mitochondrial-targeted antioxidant therapy, Mitoquinol Mesylate (MitoQ®), can restore vascular endothelial dysfunction caused by DOXO in: a) young adult mice soon after treatment; and b) middle-aged mice (treated with DOXO in adolescence) to “model” effects on middle-aged DOXO-treated childhood cancer survivors. Endothelial dysfunction is typically mediated by reduced bioavailability of the endothelium-derived dilator molecule, nitric oxide (NO), as a result of excessive production of superoxide, which reacts with NO. Dysfunctional mitochondria are a major source of overall superoxide production, due in part to inadequate compensatory increases in antioxidant defenses. DOXO has been reported to decrease vascular endothelial function, but the underlying mechanisms and potential therapeutic strategies are currently unknown. Guided by strong preliminary data, Dr. Clayton will investigate the mechanism(s) by which DOXO mediates endothelial dysfunction, using ex vivo “pharmaco-dissection” techniques, specifically focusing on the role of mitochondrial superoxide in decreasing NO bioavailability (Aim 1). Furthermore, Dr. Clayton will seek to establish initial (preclinical) proof-in-concept evidence that oral supplementation of a mitochondrial-specific antioxidant, MitoQ, can mitigate DOXO-induced endothelial dysfunction (Aim 2). Overall the proposed research has the potential to address 2 important strategic research priorities of NHLBI: 1) determine the best strategy for reducing vascular morbidity and mortality in childhood cancer survivors who are at enhanced risk of vascular events; 2) identifying therapeutic targets, establishing proof of concept, and developing data for investigational new drug applications to enable early translation of research findings to clinical applications. The sponsor, Dr. Seals, is an internationally recognized and NIH funded scientist with a strong history of successful mentoring in translational biomedical research. With his guidance, and the guidance of consulting mentors Drs. Anthony Donato, Michael Murphy and Judith Campisi, Dr. Clayton will be able to successfully complete the proposed research and training plan, preparing him to succeed as an extramurally-funded independent investigator in translational cardiovascular physiology.