Biomarkers of Heart Regeneration

描述(申请人提供)：由于对人体心脏的损伤会导致不可逆转的心肌损失，心肌梗死等损伤通常会导致心力衰竭、心律失常的易感性和死亡。与之形成鲜明对比的是，斑马鱼能够通过心肌细胞的增殖来再生损伤后的功能性心肌。最近，在成年哺乳动物的心脏中发现了一种低级别的心肌细胞增殖。加强损伤后心脏再生的治疗是预防人类心力衰竭的有吸引力的策略。然而，促进再生的因素的补充尚不清楚。在这里，我们建议使用无偏见的蛋白质组图谱和细胞类型特异性基因表达图谱来识别协调斑马鱼心脏再生的细胞外因子。我们的初步工作已经确定脑利钠肽(NPPB)是一种与心脏再生在时空上相关的分泌因子。我们将利用Cre/Lox技术产生新的转基因鱼，有条件地在特定细胞系中过表达NPPB及其受体的显性阴性形式。这些实验将能够确定NPPB的自分泌和旁分泌作用，并作为未来工作的模板，以研究已确定的其他因素的作用机制。最后，我们将评估这些因素在再生的新生小鼠心脏和再生能力差的成年小鼠心脏受到损伤后的保守性。与成年小鼠心脏相比，新生小鼠心脏优先诱导的因子是心脏再生的候选生物标志物。然后，在斑马鱼和小鼠的心脏损伤后保守的心脏损伤和再生的标记物将在从心肌梗塞患者获得的血浆储存库中进行测量。标记物水平将被测试与人类心血管结果的关系。拟议的实验将确定协调斑马鱼心脏再生的因素和从治疗上增强哺乳动物心肌细胞增殖的潜在因素。此外，我们对具有再生的分泌因子的关注将有助于开发生物标记物工具箱，用于未来的流行病学研究，以了解再生在人类心血管疾病中的作用。在接下来的几年里，我希望成为一名独立的临床医生兼科学家，专注于心脏再生。我最终希望成为一名研究心脏稳态变化如何影响心血管疾病发展的知名研究员，特别是心力衰竭。概述的实验将为未来的机制工作提供基础，以更好地了解促进再生的因素，并为一套生物标记物了解心脏稳态如何影响梗死后的心血管结果提供基础。我的工作将由肯尼思·波斯博士指导，他是再生生物学的先驱和领导者。我们将与杜克临床研究所合作，为翻译研究职业生涯提供理想的培训体验。

DESCRIPTION (provided by applicant): Because injury to the human heart results in irreversible loss of myocardium, insults such as infarction often lead to heart failure, susceptibility to arrhythmia, and death. In stark contrast, zebrafish are able to regenerate functional myocardium following injury by cardiomyocyte proliferation. Recently, a low grade of cardiomyocyte proliferation has been described in the adult mammalian heart. Therapies to augment cardiac regeneration following injury are attractive strategies to prevent human heart failure. However, the complement of factors that facilitate regeneration are unknown. Here, we propose the use of unbiased proteomic profiling and cell- type specific gene expression profiling to identify the extracellular factors that orchestrate zebrafish heart regeneration. Our preliminar work has identified brain natriuretic peptide (nppb) as a secreted factor that is spatiotemporally related to heart regeneration. We will generate novel transgenic fish to conditionally overexpress nppb and a dominant negative form of its receptor in specific cell lineages using Cre/Lox technology. These experiments will allow for the determination of autocrine and paracrine roles for nppb and serve as a template for future work to study the mechanism of action for other factors identified. Finally, we will assess conservation of these factors followin injury to the regenerative neonatal mouse heart and the poorly- regenerative adult mouse heart. Factors preferentially induced in regenerating neonatal mouse hearts compared to adult mouse hearts represent candidate biomarkers for heart regeneration. Markers of cardiac injury and regeneration that are conserved following cardiac injury in zebrafish and mice will then be measured in a repository of plasma obtained from patients following myocardial infarction. Marker levels will be tested for relation to human cardiovascular outcomes. The proposed experiments will identify factors that coordinate zebrafish heart regeneration and potential factors to therapeutically augment mammalian cardiomyocyte proliferation. In addition, our focus on secreted factors with regeneration will contribute to the development of a biomarker toolbox for future epidemiologic studies to understand the role of regeneration in human cardiovascular disease. Over the next several years, I hope to become an independent clinician-scientist focusing on heart regeneration. I ultimately hope to become an established investigator studying how variation in cardiac homeostasis affects the development of cardiovascular disease, specifically heart failure. The outlined experiments will provide a foundation for future mechanistic work to better understand the factors the facilitate regeneration and for a set biomarkers to understand how cardiac homeostasis affects cardiovascular outcomes following infarction. My work will be mentored by Dr. Kenneth Poss, PhD, a pioneer and leader in regenerative biology. We will collaborate with the Duke Clinical Research Institute, allowing for the ideal training experience for a translational research career.