Sachse Frank B, Savio-Galimberti Eleonora, Goldhaber Joshua I, Bridge John H B
Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA.
Pac Symp Biocomput. 2009:328-39. doi: 10.1142/9789812836939_0031.
Computational models of excitation-contraction (EC) coupling in myocytes are valuable tools for studying the signaling cascade that transduces transmembrane voltage into mechanical responses. A key component of these models is the appropriate description of structures involved in EC coupling, such as the sarcolemma and ion channels. This study aims at developing an approach for spatial reconstruction of these structures. We exemplified our approach by reconstructing clusters of ryanodine receptors (RyRs) together with the sarcolemma of rabbit ventricular myocytes. The reconstructions were based on dual labeling and three-dimensional (3D) confocal imaging of segments of fixed and permeabilized myocytes lying flat or on end. The imaging led to 3D stacks of cross-sections through myocytes. Methods of digital image processing were applied to deconvolve, filter and segment these stacks. Finally, we created point meshes representing RyR distributions together with volume and surface meshes of the sarcolemma. We suggest that these meshes are suitable for computational studies of structure-function relationships in EC coupling. We propose that this approach can be extended to reconstruct other structures and proteins involved in EC coupling.
心肌细胞兴奋-收缩（EC）偶联的计算模型是研究将跨膜电压转化为机械反应的信号级联反应的重要工具。这些模型的一个关键组成部分是对参与EC偶联的结构进行恰当描述，如肌膜和离子通道。本研究旨在开发一种对这些结构进行空间重建的方法。我们通过重建兔心室肌细胞的兰尼碱受体（RyR）簇以及肌膜来举例说明我们的方法。重建基于对平躺或直立的固定且透化的心肌细胞片段进行双标记和三维（3D）共聚焦成像。成像得到了穿过心肌细胞的3D横截面堆栈。应用数字图像处理方法对这些堆栈进行去卷积、滤波和分割。最后，我们创建了代表RyR分布的点网格以及肌膜的体积和表面网格。我们认为这些网格适用于EC偶联中结构-功能关系的计算研究。我们提出这种方法可以扩展到重建参与EC偶联的其他结构和蛋白质。
