Korošak D, Postić S, Stožer A, Podobnik B, Rupnik M Slak
University of Maribor, Faculty of Medicine, Institute for Physiology, Maribor, Slovenia.
University of Maribor, Faculty of Civil Engineering, Transportation Engineering and Architecture, Maribor, Slovenia.
ArXiv. 2024 Oct 23:arXiv:2410.17756v1.
Calcium signals in pancreatic cells collectives show a sharp transition from uncorrelated to correlated state resembling a phase transition as the slowly increasing glucose concentration crosses the tipping point. However, the exact nature or the order of this phase transition is not well understood. Using confocal microscopy to record the collective calcium activation of cells in an intact islet under changing glucose concentration in increasing and then decreasing way, we first show that in addition to the sharp transition, the coordinated calcium response exhibits a hysteresis indicating a critical, first order transition. A network model of cells combining link selection and coordination mechanisms capture the observed hysteresis loop and the critical nature of the transition. Our results point towards the understanding the role of islets as tipping elements in the pancreas that interconnected by perfusion, diffusion and innervation cause the tipping dynamics and abrupt insulin release.
胰腺细胞集体中的钙信号显示出一种急剧转变，即随着葡萄糖浓度缓慢增加并越过临界点，从无关联状态转变为类似相变的关联状态。然而，这种相变的确切性质或顺序尚未得到很好的理解。我们使用共聚焦显微镜以先增加后降低的方式在变化的葡萄糖浓度下记录完整胰岛中细胞的集体钙激活情况，首先表明除了急剧转变外，协调的钙反应还表现出滞后现象，这表明存在临界的一级相变。结合连接选择和协调机制的细胞网络模型捕捉到了观察到的滞后环和转变的临界性质。我们的结果有助于理解胰岛作为胰腺中的临界点元件所起的作用，这些元件通过灌注、扩散和神经支配相互连接，从而导致临界点动态变化和胰岛素的突然释放。
