Modeling of subcellular signaling crosstalk in failing myocytes

项目摘要/摘要。 心力衰竭(HF)是一种快速增长的健康问题，其特征是心肌细胞离子电流 处理、收缩功能及其神经激素调节。心力衰竭的钠调节失调日益严重 被认为是心脏功能的一个主要但未被研究的方面，与异常收缩、代谢有关 不平衡和心律不齐。通过将实验和计算研究相结合，该项目旨在分析 定量计算了不同的钠通量对氢氟酸中钠离子排布的贡献，并从机理上进行了联系 细胞内钠对线粒体功能和细胞心律失常的调节失调。 集成了相互作用的生化和生物物理功能的定量系统模型有 对于从机制上理解复杂的临床综合征(如心衰)至关重要，它涉及多个 相互作用的系统。在这里，我们将开发第一个一体化的兔心室模型框架，包括 描述细胞内钠和钙的处理，钙/钙调蛋白依赖的生物化学详细模型 蛋白激酶II(CaMKII)和β-肾上腺素能信号通路、pH调节和线粒体功能。这个 后者将基于表征线粒体钙处理和产生反应性的实验数据 兔心肌细胞内的氧物种(ROS)。该综合模型将根据 广泛的实验数据，并用于研究Na，Ca，CaMKII，ROS和β-肾上腺素能信号转导 途径有助于(1)心衰的离子重塑，(2)细胞水平的心律失常的产生，以及(3) 代谢失衡。我们还将测试针对钠相关心律失常的治疗方法，通过特定的 抑制晚期钠电流、CaMKII或ROS。 我们的研究将为这些系统提供增强的数学模型，并为 药理策略的发展。此外，拟议的项目将大大有助于 申请人的个人和职业成长。第一阶段将提供无价的培训 机会，这将提高申请者在教师职位上的竞争力。事实上，建议的 研究计划将允许在心脏生理病理学方面获得广泛的跨学科背景， 完善计算技能，培训新的实验技术(例如，细胞培养和 转基因和共聚焦显微镜实验)。完成这项培训，在一名 建立的高度多学科的指导团队，将允许申请者多样化的研究目标和 方法从导师那里，为未来独立研究的发展奠定了基础 项目和提案。在项目第二阶段继续提供支持将确保-- 离开申请者的独立学术生涯。

PROJECT SUMMARY/ABSTRACT. Heart failure (HF) is a rapidly growing health problem characterized by alterations in myocyte ion currents, Ca handling, contractile function and their neurohormonal regulation. Na dysregulation in HF is increasingly appreciated as a major, yet understudied aspect of cardiac function, linked to abnormal contraction, metabolic imbalance, and arrhythmia. By combining experimental and computational studies, this project aims to analyze quantitatively the contribution of various Na fluxes to the Na derangements in HF, and to link mechanistically intracellular Na dysregulation to mitochondrial function and cellular arrhythmias. Quantitative systems models that integrate across interacting biochemical and biophysical functions are essential for a mechanistic understanding of a complex clinical syndrome such HF, which involves multiple interacting systems. Here, we will develop the first integrative rabbit ventricular modeling framework including descriptions of intracellular Na and Ca handling, biochemically detailed models of Ca/calmodulin-dependent protein kinase II (CaMKII) and β-adrenergic signaling pathways, pH regulation, and mitochondrial function. The latter will be based on experimental data characterizing mitochondrial Ca handling and production of reactive oxygen species (ROS) in rabbit ventricular myocytes. The comprehensive model will be validated against a broad set of experimental data, and used to investigate how Na, Ca, CaMKII, ROS, and β-adrenergic signaling pathways contribute to (1) ionic remodeling in HF, (2) arrhythmia generation at the cellular level, and (3) metabolic imbalance. We will also test therapeutic approaches that target Na-related arrhythmias by specific inhibition of late Na current, CaMKII or ROS. Our study will provide enhanced mathematical models of these systems and substantially inform the development of pharmacological strategies. Moreover, the proposed project will significantly contribute to the personal and professional growth of the applicant. The first phase will provide an invaluable training opportunity, which will enhance the applicant’s competitiveness for faculty positions. Indeed, the proposed research plan will allow for acquisition of a broad interdisciplinary background in cardiac physio-pathology, refinement of computational skills, and training in new experimental techniques (i.e., cell culture and transfection, and confocal microscopy experiments). Completion of this training, under the supervision of an established and highly multidisciplinary mentoring team, will allow the applicant to diversify research goals and methods from those of his mentors, laying the groundwork for the development of future independent research projects and proposals. Continuation of the support during the second phase of the project will ensure the kick- off of the applicant’s independent academic career.