Reactive Inflammatory Species in Heart Failure

描述(申请人提供)：在容量超负荷的心脏中，一系列复杂的代偿事件会导致细胞外基质(ECM)重构和心肌细胞功能的变化，最终导致充血性心力衰竭(HF)。越来越多的证据表明，在终末期心力衰竭模型中，活性氧(ROS)和氮(RNS)物种统称为反应性炎症物种(RIS)，以及调节其生物利用度的酶与收缩衰竭和心肌结构损伤有关。然而，RIS与HF的时间进程之间的关系尚未得到广泛的研究。采用大鼠主动脉下腔静脉瘘(ACF)模型，在体内严格定义了3个关键的临床相关时间点：急性(2-5天)、慢性代偿期(4-8周)和慢性失代偿期(15-21周)。初步研究表明，在HF急性期，肌丝蛋白、基质降解酶和信号分子的酪氨酸硝化增加。在急性期和向失代偿性心衰过渡的过程中，也观察到RIS生成酶和抗氧化剂防御之间的失衡。此外，我们还发现RIS可引起成人心肌细胞收缩功能障碍。这导致假设RIS是不利的左心室重构和收缩功能障碍的重要中介，而收缩功能障碍是容量超负荷诱导的心衰发生和发展的基础。目的1将建立反应性炎性物质与容量超负荷所致心力衰竭的发生和进展之间的联系。RIS将使用微渗析、ESR(电子自旋共振)和标准生化分析相结合的方法进行测量。一系列药物干预和转基因方法(iNOS(-/-)、髓过氧化物酶(-/-)、超氧化物歧化酶(-/-))将被用来在体内操纵RIS水平。蛋白质组学方法将用于鉴定RIS调节的蛋白质。目的2探讨RIS参与ACF诱导的心衰左室重构的机制，特别是体内ECM周转和体外心脏成纤维细胞对基质金属蛋白酶(MMPs)活性的调节。AIM 3将使用视频边缘显微镜、荧光钙成像和免疫细胞化学来确定在HF进展过程中RIS易感性改变是否对心肌细胞有贡献。拟议的研究对于开发针对氧化剂诱导的损伤的治疗策略具有重要意义，并可能对HF的治疗具有重要意义。

DESCRIPTION (provided by applicant): In hearts with volume overload, a complex sequence of compensatory events result in a continual state of extra cellular matrix (ECM) remodeling and by changes in myocyte function and eventually leads to congestive heart failure (HF). Increasing evidence suggests that reactive oxygen (ROS) and nitrogen (RNS) species, collectively termed reactive inflammatory species (RIS), and the enzymes that regulate their bioavailability are associated with contractile failure and myocardial structural damage in end-stage HF models. However, the relationship between RIS and the temporal progression of HF has not been extensively studied. Using an aortocaval fistula (ACF) model in the rat, 3 key, clinically relevant, time points in the temporal progression of volume overload have been rigorously defined in vivo: acute (2-5 days), chronic compensated (4-8 weeks), and chronic decompensated (15-21 weeks). Preliminary studies indicate increased tyrosine nitration of myofilament proteins, matrix degrading enzymes and signaling molecules during the acute phase of HF. An imbalance between RIS generating enzymes and antioxidant defenses was also observed acute stage and during the transition to decompensated HF. Moreover, we have found that RIS cause contractile dysfunction in isolated adult cardiac myocytes. This led to the hypothesis that RIS are important mediators of adverse LV remodeling and contractile dysfunction that underlie the development and progression of volume overload-induced HF. Aim 1 will establish a link between reactive inflammatory species and the development and progression of volume overload-induced CHF. RIS will be measured using a combination of microdialysis, ESR (electron spin resonance) and standard biochemical assays. A series of pharmacological interventions and transgenic approaches (iNOS(-/-), myeloperoxidase (-/-), SOD overexpressors) will be used to manipulate RIS levels in vivo. A proteomics approach will used to identify RIS-modulated proteins. Aim 2 will determine the mechanisms by which RIS contribute to LV remodeling in ACF-induced HF, with particular focus on ECM turnover in vivo and the regulation matrix metalloproteinase (MMP) activation by cardiac fibroblasts in vitro. Aim 3 will use video edge microscopy, fluorescent Ca 2+ imaging and immunocytochemistry to determine whether altered susceptibility to RIS during HF progression contributes to cardiomyocyte. The proposed investigations are fundamentally important to the development of therapeutic strategies targeted to oxidant-induced injury and may have important implications in the treatment of HF.