Department of Physics, University of Maribor, Koroska cesta 160, SI-2000 Maribor, Slovenia.
Biophys Chem. 2010 May;148(1-3):42-50. doi: 10.1016/j.bpc.2010.02.006. Epub 2010 Feb 11.
Calcium signaling controls several essential physiological functions in different cell types. Hence, it is not surprising that different aspects of Ca(2+) dynamics are in the focus of in-depth and extensive investigations. Efforts concentrate on the development of proper theoretical models that would provide a unified description of Ca(2+) signaling. Remarkably, experimentally recorded Ca(2+) signals exhibit a rather large diversity, which can be observed irrespective of the cell type, measuring techniques, or the nature of the signal. Our goal in the present study therefore is to present a theoretical explanation for the variability observed in experiments, whereby we focus on caffeine-induced Ca(2+) responses in isolated airway myocytes. By employing a stochastic model, we first test whether the observed variability can be attributed to intrinsic fluctuations that are a common feature of biochemical reactions that govern Ca(2+) signalization. We find that stochastic effects, within ranges that correspond to actual conditions in the cell, are far too modest to explain the large diversity observed in experimental data. Foremost, we reveal that only cell variability in theoretical modeling can appropriately describe the observed diversity in single-cell responses.
钙信号控制着不同细胞类型中的几种基本生理功能。因此，不同方面的 Ca(2+)动力学成为深入广泛研究的焦点也就不足为奇了。研究工作集中在开发适当的理论模型上，这些模型将为 Ca(2+)信号提供统一的描述。值得注意的是，实验记录的 Ca(2+)信号表现出相当大的多样性，无论细胞类型、测量技术或信号性质如何，都可以观察到这种多样性。因此，我们在本研究中的目标是对实验中观察到的可变性提出理论解释，其中我们重点关注分离的气道平滑肌细胞中咖啡因诱导的 Ca(2+)反应。通过采用随机模型，我们首先测试观察到的可变性是否可以归因于内在波动，这是控制 Ca(2+)信号转导的生化反应的共同特征。我们发现，在与细胞内实际情况相对应的范围内，随机效应太小，无法解释实验数据中观察到的大的多样性。最重要的是，我们揭示了只有在理论建模中的细胞变异性才能适当地描述单个细胞反应中观察到的多样性。
