Follistatin-like 1 and the cardiac secretome in human heart failure

描述(申请人提供)：对病理刺激作出反应的心肌肥大是不适应性心脏重塑的一个共同特征，最终导致收缩功能障碍、心力衰竭、左心室(LV)功能障碍和心肌病态。心肌细胞死亡是病理性心脏重塑的一个特征，调节细胞死亡途径是预防不良心脏重塑和症状性心力衰竭的合理策略。包括转化生长因子-2超家族蛋白在内的多种细胞因子/生长因子的失调参与了左心室收缩期心衰的复杂发病机制。卵泡抑素家族蛋白通常通过结合和修饰转化生长因子-2超家族成员来发挥作用。到目前为止，人们对卵泡抑素样蛋白在心力衰竭和心脏重塑中的作用知之甚少。我们的初步数据表明，在卵泡抑素分泌蛋白家族中，卵泡抑素样蛋白1(FSTL1)和卵泡抑素样蛋白3(Fst13)的转录本在小鼠肥厚和缺血心脏中显著上调，而不是卵泡抑素。更重要的是，我们的试点数据还显示，与对照组相比，伴左室收缩功能不全(左心功能受抑)的心肌病患者的血清FSTL1水平升高。此外，左心功能正常者的FSTL1水平降低。此外，体外实验数据还表明，FSTL1和FSTL3的作用相反：FSTL1保护缺氧/复氧心肌细胞的凋亡，而FSTL3促进心肌细胞的凋亡。这一建议的中心假设是，卵泡抑素分泌蛋白家族的成员FSTL1和FstL3在心力衰竭中有不同的模式，并在左心室收缩期心衰和心脏重构的发病机制中起作用。我们将探讨循环FSTL1和FSTL3水平与心脏重构的关系。在目标1中，我们将检验FSTL1和FSTL3水平在左收缩心力衰竭患者中发生改变并与心脏重构相关的假设。在左心室收缩功能不全患者中，细胞因子和生长因子增加，并与病理性心脏结构重构(超声心动图)和心肌细胞重构的生物标记物(如BNP)相关。在目标2中，我们将检验这一假设，即FSTL1和FSTL3水平的变化(在基线和一年之间)与疾病进展(由超声心动图上的左心室质量确定)和左心室收缩期心衰的BNP水平相关。这项工作可能有助于证实心脏分泌体在心脏不良重构中的作用，并可能为预防或治疗左心室收缩功能不全提供新的治疗靶点。与我的同事一起，这项拟议的研究将有助于更好地理解心脏分泌体在病理性心脏重构中的作用，以及它在心力衰竭心脏不良重构发病机制中的作用。 与公共卫生相关：心力衰竭是世界上最严重的公共卫生问题，仅在美国就有500多万人受到影响，是每年5.3万人死亡的主要原因。尽管应用了循证治疗和指南，但20年来心力衰竭的发病率并没有下降，而影响心力衰竭发病和进展的机制仍不完全清楚。心脏分泌的新因素可能在心脏本身对心力衰竭的反应中发挥着重要的病理生理学作用。

DESCRIPTION (provided by applicant): Cardiac hypertrophy in response to pathological stimuli represents a common feature of maladaptive cardiac remodeling, ultimately leading to the development of contractile dysfunction, heart failure, left ventricular (LV) dysfunction and a cardiomyopathic phenotype. Cardiomyocyte cell death is a feature of pathological cardiac remodeling, and modulating the cell death pathway represents a logical strategy to prevent adverse cardiac remodeling and symptomatic heart failure. Dysregulation of a number of cytokines/growth factors including the TGF-2 superfamily of proteins contributes to the complex pathogenesis of LV systolic heart failure. The follistatin family proteins generally function by binding to and modifying the members of the TGF-2 superfamily. To date, little is known about the role of follistatin-like proteins in heart failure and cardiac remodeling. Our pilot data demonstrate that among the follistatin family of secreted proteins, transcripts of follistatin-like 1 (Fstl1) and follistatin-like 3 (Fstl3), but not follistatin, are dramatically upregulated in murine hypertrophic and ischemic hearts. More importantly, our pilot data also shows increased serum Fstl1 levels in cardiomyopathy patients with LV systolic dysfunction (depressed LV function) compared to control subjects. Additionally Fstl1 levels were decreased in subjects whose LV function normalized. Furthermore in vitro pilot data also suggests opposing actions of Fstl1 and Fstl3: Fstl1 protects against apoptosis whereas Fstl3 promotes apoptosis in cardiac myocytes that have been subjected to hypoxia/reoxygenation. The central hypothesis of this proposal is that members of the follistatin family of secreted protein, Fstl1 and Fstl3, have distinct patterns in heart failure and contribute to the pathogenesis of LV systolic heart failure and cardiac remodeling. We will explore the relationship between circulating Fstl1 and Fstl3 levels and cardiac remodeling. In Aim 1 we will test the hypothesis that Fstl1 and Fstl3 levels are altered in LV systolic heart failure patients and are associated with cardiac remodeling. In patients with LV systolic dysfunction, cytokines and growth factors are increased and are associated with pathologic cardiac structural remodeling (by echocardiography) and a biomarker of cardiomyocyte remodeling (e.g., BNP). In Aim 2 we will test the hypothesis that changes in Fstl1 and Fstl3 levels (between baseline and at one year) are associated with disease progression (as determined by LV mass on echocardiography) and BNP levels in LV systolic heart failure. This work may lead to the verification of the role of the cardiac secretome in adverse cardiac remodeling, and could provide new therapeutic targets for prevention or treatment of LV systolic dysfunction. Together with my colleagues, the proposed study will lead to a better understanding of the cardiac secretome in pathological cardiac remodeling and its contribution to the pathogenesis of adverse cardiac remodeling in HF PUBLIC HEALTH RELEVANCE: Heart failure is the most significant public health problems in the world and in the United States alone, afflicts more than 5 million people and is the primary cause of 53,000 deaths annually. Despite the application of evidence-based therapies and the utilization of guidelines the incidence of HF has not declined for two decades while the mechanisms influencing the pathogenesis and progression of HF remain incompletely understood. Novel factors secreted by the heart likely plays an important pathophysiology role in how the heart itself responds to heart failure.