Reductive Stress Induces Proteotoxic Cardiac Disease

传统上，氧化应激被认为是心脏蛋白质质量控制（PQC）的病理学， 使抗氧化剂的治疗潜力合理化。然而，许多抗氧化剂的临床试验 补充剂未能产生积极的影响，相反，在各种器官中表现出不利的影响， 包括心血管系统中的那些。新出现的证据表明，还原应激（RS），也 称为抗氧化应激，可能导致ER应激和缺失/未折叠蛋白质积累。充分 理解RS介导的蛋白毒性的分子相互作用和心肌损伤的时间范围 经历从适应性到适应不良重塑的转变，关键是要确定分子 参与者、他们的动态相互作用，以及由此产生的顺序事件（例如，自噬）调节PQC。 最近，我们令人兴奋和新颖的临床观察揭示了慢性RS（cRS）的潜在联系。 人类心力衰竭（HF）的疾病进展。我们筛选了一组选定的HF患者（n=50，无 其他主要合并症）的外周血氧化还原状态;其中，一个子集（n=8）显示RS 条件我们提出的研究将需要利用蛋白质组学方法的翻译组件， 分子生物学，以更好地了解小鼠模型中RS的病因，并确定其与HF的相关性 患者我们的中心假设是cRS将改变蛋白质组特性（例如，蛋白质动力学和后 翻译修饰，或PTM）和损伤自噬信号传导，导致持续的蛋白毒性， 心脏功能障碍，从而在动物模型和人类心脏病中驱动适应不良的重塑。 我们提出了三个目标：目标1将确定改变的蛋白质动力学，重新分布的PTM， 自噬亚蛋白质组。我们将在控制和cRS中定义“缩减组签名” 表型目的2将研究cRS对自噬进行性损伤的影响， 随着时间的推移，心肌中的货物清除和蛋白毒性不足。我们将评估自噬体 形成，自噬通量和蛋白质折叠能力，并检查是否增强 自噬延迟和/或防止小鼠中的蛋白毒性。目的3将检查“氧化还原表型”， 使用基于HPLC的（a）GSH氧化还原比，（B）脂质过氧化， 和（c）总抗氧化能力，以及提取HF患者的分子“还原组特征”， RS使用计算平台来确定基本蛋白质组特征和调节途径。这 目的是建立RS假说在人类HF中的转化值。 我们已经组建了一个多学科团队（科学家和医生），他们在氧化还原方面拥有专业知识 生物学、生物化学、蛋白质组学和计算分析。RS的遗传小鼠模型， 技术平台，以及在小鼠和人类中评估RS的生化测定都建立在 我们的实验室我们期望圆满完成我们提出的目标。

Conventionally, oxidative stress is considered pathological to cardiac protein quality control (PQC), which rationalizes the therapeutic potential of antioxidants. However, many clinical trials of antioxidant supplementation failed to deliver a positive impact and, rather, demonstrated adverse effects in various organs, including those in the cardiovascular system. Emerging evidence suggests that reductive stress (RS), also known as antioxidative stress, may cause ER stress and accumulation of mis/unfolded proteins. To fully comprehend the molecular interplay underlying RS-mediated proteotoxicity and the time frame for myocardium experiencing a transition from adaptive to maladaptive remodeling, it is critical to identify the molecular participants, their dynamic interplay, and resulting sequential events (e.g., autophagy) that regulate PQC. Recently, our exciting and novel clinical observations revealed a link of chronic RS (cRS) underlying disease progression of human heart failure (HF). We screened a selected group of HF patients (n=50, without other major comorbidities) for their peripheral blood redox state; among them, a subset (n=8) displayed the RS condition. Our proposed study will entail a translational component utilizing proteomics approaches and molecular biology to better understand the etiology of RS in mouse models and to identify its relevance in HF patients. Our central hypothesis is that cRS will alter proteome properties (e.g., protein dynamics & post- translational modifications, or PTMs) and damage autophagy signaling, leading to persistent proteotoxicity and cardiac dysfunction, thereby driving maladaptive remodeling in animal models and in human heart diseases. We propose three aims: Aim 1 will determine altered protein dynamics, redistributed PTMs, and perturbed autophagy subproteome in RS conditions. We will define the “reductome signatures” in control and cRS phenotypes. Aim 2 will examine the impact of cRS on progressive damage of autophagy that may lead to insufficient cargo-clearance and proteotoxicity in the myocardium over time. We will assess autophagosome formation, autophagy flux, and protein folding capacity under cRS conditions and examine whether enhancing autophagy delays and/or prevents proteotoxicity in mice. Aim 3 will examine the “redox phenotype” in the peripheral blood of HF patients using HPLC based quantification of (a) GSH redox ratio, (b) lipid peroxidation, and (c) total antioxidant capacity, as well as extract the molecular “reductome signatures” in HF patients with RS using a computational platform to determine essential proteome features and regulatory pathways. This aim will establish a translational value for the RS hypothesis in human HF. We have assembled a multidisciplinary team (scientists & physicians) with documented expertise in redox biology, biochemistry, proteomics, and computational analyses. The genetic mouse models of RS, the technology platforms, and the biochemical assays to evaluate RS in mouse and in human are all established in our laboratories. We anticipate the successful completion of our proposed goals.