VOLTAGE-CA DYNAMICS: CELL MODELS AND THERAPEUTICS

电压-CA 动力学：细胞模型和治疗

• 批准号: 7108464
• 负责人: JAMES M WEISS
• 金额: $ 49.89万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-10 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7108464
• 关键词: action potentials; biological signal transduction; calcium flux; calcium transporting ATPase; cardiovascular disorder therapy; disease /disorder model; disease /disorder prevention /control; heart electrical activity; heart failure; intracellular transport; laboratory rat; mathematical model; sudden cardiac death; therapy design /development; tissue /cell culture; transfection; two dimensional gel electrophoresis; ventricular fibrillation

In the diseased heart, the high risk of Sudden Cardiac Death has traditionally been ascribed to increased tissue heterogeneity associated with disease-related structural and electrical remodeling, which predisposes cardiac tissue to electrical wavebreak and ventricular fibrillation (VF). However, recent studies indicate that dynamic wave instability operates synergistically with pre-existing tissue heterogeneity to promote wavebreak. Dynamic wave stability is regulated by multiple factors, including electrical restitution, intracellular Ca (Cai) cycling, cardiac memory, and electrotonic currents. The goal of this project is to combine mathematical and experimental biology to develop novel therapeutics for VF, based on altering global voltage-Cai dynamics to increase wave stability. To develop this concept, the first goal is to overcome shortcomings of existing action potential (AP) models by incorporating realistic voltage-Cai cycling dynamics into AP models for normal and failing adult rabbit ventricular myocytes and neonatal rat ventricular myocytes, validated experimentally against patch clamp and Cai imaging data. The second aim is to explore interactions between voltage-Cai dynamics and tissue heterogeneity experimentally in the simplified 2D geometry of cultured neonatal rat ventricular tissue monolayers, complementing the theoretical studies in Project 2. The third aim is to use the developed AP models in combination with biological experiments to develop and evaluate specific molecular targets for suppressing wave instability driven by Vm-Cai cycling dynamics, in collaboration with Projects 2, 3 and 4. Based on preliminary studies showing that the L-type Ca current sits at a critical focal point controlling multiple aspects of dynamic wave stability, we will focus on modification of this current as the initial strategy. We will utilize mathematical modeling, patch clamp studies, optical mapping, and adenoviral gene transfer into cultured neonatal rat ventricular monolayers and, in collaboration with Project 3, intact rabbit hearts as a proof-of-concept strategy for gene therapy.

在患病的心中，传统上，心脏猝死的高风险被归因于 与疾病相关结构和电的组织异质性增加 重塑，使心脏组织易受电波和心室纤颤 （VF）。然而，最近的研究表明，动态波不稳定性与先前存在的组织异质性协同起作用，以促进波浪破裂。动态波稳定性由多种因素调节，包括电恢复，细胞​​内CA（CAI）循环，心脏记忆和电流电流。该项目的目的是将数学和实验生物学结合起来，以开发VF的新型治疗剂，以改变全局电压式动力学以提高波浪稳定性。为了发展这个概念，第一个目标是通过将逼真的电压循环动力学纳入AP模型中，以克服现有动作电位（AP）模型的缺点，以实现正常和失败的成年兔心室心肌细胞和新生儿大鼠心室心肌细胞，对Patch夹和CAI成像数据进行了实验性验证。第二个目的是探索在培养的新生儿大鼠心室组织单层的简化2D几何学中，在实验中探索电压-CAI动力学与组织异质性之间的相互作用，并补充了项目2中的理论研究。 将开发的AP模型与生物学实验结合使用，以开发和评估特定的分子靶标，以抑制由VM-CAI驱动的波不稳定性 自行车动力学与项目2、3和4合作。基于初步研究表明，L型CA电流位于控制动态波稳定性多个方面的关键焦点，我们将专注于将此电流作为初始策略的修改。我们将利用数学建模，斑块夹研究，光学映射和腺病毒基因转移到培养的新生大鼠心室单层中，并与项目3合作，完整的兔心脏作为基因疗法的概念验证策略。