Protein Misfolding Diseases and Oxido-Reductive Pathways

描述 摘要 心力衰竭和几种神经退行性疾病的某些遗传模式的特征在于蛋白质错误折叠状态，其潜在机制和病理生理学知之甚少。有效的治疗主要是作为目标而存在，而不是作为临床实施。氧化应激引起的大分子损伤是思考许多疾病的必要条件。我们的实验室通过证明在人类中发现的表现出蛋白质折叠心肌病的小鼠心脏处于过度活跃的抗氧化系统的“还原应激”下，对这种范式提出了挑战。降低产生还原剂NADPH的葡萄糖-6-磷酸脱氢酶（G6 PD）的功能，通过改善还原性应激、侵略性蛋白质组形成、肥大、心力衰竭和死亡来“治愈”小鼠的疾病。该实验定义了一种新的因果机制，并暗示G6 PD是一种潜在的治疗靶点。我们假设应激反应和抗氧化途径经历了一个致病性转变，并因大分子应激（例如，错误折叠的蛋白质）。我们进一步提出，其他心脏和神经退行性疾病的结果从类似的致病性转变。我们的先锋奖提案旨在开发一个强大的实验平台，用于探索还原性应激疾病的机制。我们的工作将从在遗传上顺从的果蝇Drosophila melanogaster中模拟还原应激的研究，通过培养的小鼠和人类细胞，到整个小鼠，最后到我们开发诊断工具的患者。尖端成像技术将被开发用于监测活细胞和组织中的氧化还原对和毒性。果蝇的基因筛选将指导新基因的鉴定，并确定预防还原性应激疾病的潜在治疗化合物的效果。在小鼠中验证相互作用的基因和途径将为我们提供药理学的候选靶点。

DESCRIPTION Abstract Certain inherited modes of heart failure and several neurodegenerative diseases are characterized by protein misfolding states whose underlying mechanism(s) and pathophysiology are poorly understood. Effective therapies exist primarily as goals, not as clinical implementations. Macromolecular damage induced by oxidative stress is the sine qua non for thinking about many diseases. Our laboratory has challenged this paradigm by demonstrating that mouse hearts exhibiting protein-folding cardiomyopathy found in humans are under 'reductive stress' from an over-active antioxidative system. Decreasing the function of glucose-6-phosphate dehydrogenase (G6PD), which generates the reductant NADPH, "cures" the disease in mice by ameliorating reductive stress, aggresome formation, hypertrophy, heart failure and death. This experiment defines a novel causal mechanism and implicates G6PD as a potential therapeutic target. We hypothesize that stress response and anti-oxidative pathways undergo a pathogenic transition, and become dysregulated by macromolecular stresses (e.g., misfolded proteins). We further propose that other cardiac and neurodegenerative diseases result from similar pathogenic transition. Our Pioneer Award proposal is designed to develop a robust experimental platform for exploring the mechanisms of reductive stress disease. Our work will extend from studies that model reductive stress in the genetically amenable fruit fly Drosophila melanogaster, through cultured mouse and human cells, to whole mice, and finally into patients as we work to develop diagnostic tools. Cuttingedge imaging techniques will be developed for monitoring redox couples and toxicities in living cells and tissues. Genetic screens in Drosophila will guide the identification of new genes and determine the effects of potentially therapeutic compounds that prevent reductive stress disease. Validation in mice of interacting genes and pathways will provide us target candidates for pharmacolog