Excitability Between Cardiac and Non-Cardiac Cells

心肌细胞和非心肌细胞之间的兴奋性

• 批准号: 6859539
• 负责人: Robin M Shaw
• 金额: $ 12.04万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-30 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6859539
• 关键词: action potentials; arrhythmia; cardiac myocytes; cell cell interaction; cell population study; cell transplantation; computer simulation; embryonic stem cell; fluorescent dye /probe; gap junctions; gene expression; genetically modified animals; heart electrical activity; heart ventricle; laboratory mouse; membrane channels; mixed tissue /cell culture; myoblasts; myocardium; single cell analysis; voltage /patch clamp

DESCRIPTION (provided by applicant): Cell transplantation of non-cardiac origin cells into myocardium is an attractive approach for restoring lost cardiac function, however, the electrical function of transplanted cells remains poorly understood. The transplanted cells are unlikely to communicate electrically as native cardiomyocytes do within the cardiac syncytium. In fact, the communication between cardiac and non-cardiac cells may be pro-arrhythmic, as preliminary reports have suggested. Thus, it is crucial to define the requirements for safe and effective electrical communication between transplanted non-cardiac cells and host cardiomyocytes. Cardiac excitability is determined by membrane ion channel activity and cell-to-cell coupling via cardiac gap junctions. Our preliminary studies indicate that primary cardiac cells can couple and electrically communicate with embryonic stem cell derived cardiomyocytes, but it is not clear that this communication is sufficient to be functional within a cardiac synctium. Our computer simulations have demonstrated that decreased gap junction coupling can lead to sustained ventricular arrhythmias. We are developing an in vitro experimental system in which labeled primary ventricular cardiomyocytes are co-cultured with embryonic stem cell derived cardiomyocytes and skeletal myocytes. We perform dual cell patch clamping to quantify the electrical communication between cell pairs and use these data with computer models to determine arrhythmogenic potential of regions of transplanted cells. As our preliminary data indicate that limited gap junction coupling can be arrhythmogenic, we will experimentally overexpress coupling protein and repeat assessment of coupling conductance and arrhythmogenesis. The proposed studies seek to establish the mechanisms of electrical communication between primary ventricular myocytes and putative candidates for cellular transplantation. The results will provide insight into the electrical impact of cells transplanted into ventricular myocardium, and lead to a therapeutic approach to decrease their arrhythmogenic behavior.

描述(由申请人提供)： 将非心脏来源的细胞移植到心肌中是一种有吸引力的恢复失去的心功能的方法，然而，移植细胞的电功能仍然知之甚少。移植的细胞不太可能像天然心肌细胞那样在心脏合体内进行电学交流。事实上，正如初步报道所表明的那样，心脏和非心脏细胞之间的通讯可能是促心律失常的。因此，确定移植的非心肌细胞和宿主心肌细胞之间安全有效的电通讯的要求是至关重要的。心脏的兴奋性是由膜离子通道活性和通过心脏缝隙连接的细胞与细胞的偶联决定的。我们的初步研究表明，原代心肌细胞可以与胚胎干细胞来源的心肌细胞偶联并进行电通讯，但目前尚不清楚这种通讯是否足以在心脏联合体中发挥作用。我们的计算机模拟表明，缝隙连接耦合的减少可以导致持续性的室性心律失常。我们正在开发一种体外实验系统，在该系统中标记的原代心肌细胞与胚胎干细胞来源的心肌细胞和骨骼肌细胞共同培养。我们执行双细胞膜片钳技术来量化细胞对之间的电通讯，并使用这些数据和计算机模型来确定移植细胞区域的心律失常潜能。由于我们的初步数据表明，有限缝隙连接偶联可能导致心律失常，我们将在实验中过表达偶联蛋白，并重复评估偶联电导和心律失常的发生。建议的研究试图建立原代心肌细胞和可能的细胞移植候选细胞之间的电通讯机制。这一结果将为深入了解细胞移植到心肌中的电学影响提供线索，并导致减少其心律失常行为的治疗方法。