Fazekas Fruzsina, Vasbányai Lilla, Berekméri Eszter
Department of Zoology, University of Veterinary Medicine Budapest, Budapest, Hungary.
Retina Laboratory, Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary.
Biol Futur. 2025 Jun 29. doi: 10.1007/s42977-025-00270-6.
Intracellular calcium waves refer to the coordinated propagation of increased free calcium ion (Ca) concentration in the cytoplasm. Ca is one of the major intracellular second messengers which coordinates many cells function including gene transcription, division, and cell apoptosis. The spread of the ions in the cytoplasm is not the same in all cell types. Experiments indicate the strength of the stimuli, the site of the first Ca entry and the localization of the organelles influence the Ca propagation and may lead to functional compartmentalization. Polarized cells with complex anatomy already have anatomical subparts (like processes) which elevate the probability of the functional separation between the cell parts. Cells are stimulated at special parts where the receptors/channels are located. Ca enters the cell via ligand or voltage gated calcium channels, connexin channels from the neighboring cells or with the activation of G-protein coupled receptors which activate Ca release from the cytosolic Ca stores. The emptying stores may activate store-operated Ca channels, too. These local signals could globalize and elevate free Ca concentration in the cells. Smaller, more compact cells form a uniformly activated cell, however, in polarized cells this cannot happen in each time, leads to spatiotemporally different subpart activation. In this review, we discuss the main mechanisms of the cells which involved in Ca signaling and the possible methods how a single event (a Ca spike) can form slow intracellular Ca wave and globalized signal. Intracellular Ca waves were found in multiple cell types starting with simple egg cells. Here, we bring examples to anatomically more complex polarized cells with processes, but without excitability: the radial glia, astrocytes, Müller glia and osteocytes as a cell does not connect strongly to sensory-neural structures.
细胞内钙波是指细胞质中游离钙离子（Ca）浓度升高的协同传播。Ca是主要的细胞内第二信使之一，它协调许多细胞功能，包括基因转录、分裂和细胞凋亡。离子在细胞质中的扩散在所有细胞类型中并不相同。实验表明，刺激强度、首次Ca进入的部位以及细胞器的定位会影响Ca的传播，并可能导致功能区室化。具有复杂解剖结构的极化细胞已经有解剖学上的亚部分（如突起），这增加了细胞部分之间功能分离的可能性。细胞在受体/通道所在的特殊部位受到刺激。Ca通过配体门控或电压门控钙通道、来自相邻细胞的连接蛋白通道或通过激活G蛋白偶联受体进入细胞，这些受体激活胞质Ca储存中的Ca释放。排空储存也可能激活储存操纵的Ca通道。这些局部信号可以全局化并提高细胞内的游离Ca浓度。较小、更紧凑的细胞形成均匀激活的细胞，然而，在极化细胞中，这种情况并非每次都能发生，会导致时空上不同的亚部分激活。在这篇综述中，我们讨论了参与Ca信号传导的细胞的主要机制，以及单个事件（一个Ca尖峰）如何形成缓慢的细胞内Ca波和全局信号的可能方法。细胞内钙波在多种细胞类型中都有发现，从简单的卵细胞开始。在这里，我们以具有突起但无兴奋性的解剖学上更复杂的极化细胞为例：放射状胶质细胞、星形胶质细胞、穆勒胶质细胞和骨细胞，因为这些细胞与感觉神经结构的连接不紧密。
