Subcellular organization and Ca+2 signaling in heart failure

描述（由申请人提供）： Ca 2+信号传导功能障碍在许多情况下发生在心肌中，并且与 有不同的心脏病本项目旨在定量表征Ca 2 + 发生在心室肌细胞中的信号缺陷，并研究其原因。 功能障碍将对单个心室肌细胞进行共焦Ca 2+成像， 以高时间和空间分辨率测量Ca 2+火花和细胞Ca 2+信号。 细胞内Ca ~（2+）的光释放会迅速改变细胞内Ca ~（2+）的含量， 用全细胞膜片钳方法控制电位。计划中的实验将 揭示了Ca 2+电流、Ca 2+火花和Ca 2+的其他成分之间的联系 信号了 初步实验提出了一个中心假设： 兴奋-收缩偶联可能是Ca 2+信号转导缺陷的基础， 观察这种重塑可能涉及细胞骨架蛋白的重组， L型Ca 2+通道蛋白的定位和/或兰尼碱受体Ca 2+释放 通道或横小管的重组。为了研究这一假设， 小鼠、大鼠疾病模型和新的细胞培养方法将被用来检查 Ca 2+信号缺陷的分子原因。将进行具体实验， 表征细胞骨架元素在Ca 2+信号传导缺陷中的作用。 因此，计划的工作应该扩大我们对心脏中Ca 2+信号传导的理解， 阐明它如何在疾病中变得功能失调。此外，工作应提供 深入了解心脏细胞的亚细胞组织，并阐明 横小管、细胞骨架结构和电压门控和配体门控通道。

DESCRIPTION (provided by applicant): Ca2+ signaling dysfunction occurs in heart muscle under many conditions and is associated with diverse cardiac pathologies. This project seeks to characterize quantitatively Ca2+ signaling defects that occur in cardiac ventricular myocytes and to investigate the causes of the dysfunction. Confocal Ca2+ imaging of single ventricular myocytes will be carried out to measure Ca2+ sparks and the cellular Ca2+ signal at high temporal and spatial resolution. Intracellular Ca2+ will be rapidly changed by photorelease of caged Ca2+ while membrane potential is controlled with a whole cell patch clamp method. The planned experiments will reveal the links between the Ca2+ current, the Ca2+ sparks and other components of the Ca2+ signal. Preliminary experiments suggest a central hypothesis: a disruption of the machinery of excitation-contraction coupling may underlie the Ca2+ signaling defects that have been observed. Such remodeling may involve reorganization of the cytoskeletal proteins, altered positioning of L-type Ca2+ channel proteins and/or the ryanodine receptor Ca2+ release channels or re-organization of the transverse-tubules. To investigate the hypothesis, transgenic mice, rat models of disease and new cell culture methods will be used to examine the molecular causes of the Ca2+ signaling defects. Specific experiments will be carried out to characterize the role of cytoskeletal elements in the Ca2+ signaling defects. The planned work should therefore broaden our understanding of Ca2+ signaling in heart and clarify how it may become dysfunctional in disease. Additionally, the work should provide insight into the subcellular organization of the heart cell and illuminate the links between transverse tubules, cytoskeletal structures, and voltage- and ligand-gated channels.