Gosak Marko, Markovič Rene, Fajmut Aleš, Marhl Marko, Hawlina Marko, Andjelić Sofija
Institute of Physiology, Faculty of Medicine, University of Maribor, Slovenia.
Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia.
PLoS One. 2015 Dec 4;10(12):e0143781. doi: 10.1371/journal.pone.0143781. eCollection 2015.
In this work we investigated how modifications of the Ca2+ homeostasis in anterior lens epithelial cells (LECs) are associated with different types of cataract (cortical or nuclear) and how the progression of the cataract (mild or moderate) affects the Ca2+ signaling. We systematically analyzed different aspects of intra- and inter-cellular Ca2+ signaling in the human LECs, which are attached to surgically isolated lens capsule (LC), obtained during cataract surgery. We monitored the temporal and spatial changes in intracellular Ca2+ concentration after stimulation with acetylcholine by means of Fura-2 fluorescence captured with an inverted microscope. In our analysis we compared the features of Ca2+ signals in individual cells, synchronized activations, spatio-temporal grouping and the nature of intercellular communication between LECs. The latter was assessed by using the methodologies of the complex network theory. Our results point out that at the level of individual cells there are no significant differences when comparing the features of the signals with regard either to the type or the stage of the cataract. On the other hand, noticeable differences are observed at the multicellular level, despite inter-capsule variability. LCs associated with more developed cataracts were found to exhibit a slower collective response to stimulation, a less pronounced spatio-temporal clustering of LECs with similar signaling characteristics. The reconstructed intercellular networks were found to be sparser and more segregated than in LCs associated with mild cataracts. Moreover, we show that spontaneously active LECs often operate in localized groups with quite well aligned Ca2+ activity. The presence of spontaneous activity was also found to affect the stimulated Ca2+ responses of individual cells. Our findings indicate that the cataract progression entails the impairment of intercellular signaling thereby suggesting the functional importance of altered Ca2+ signaling of LECs in cataractogenesis.
在这项研究中，我们探究了前房晶状体上皮细胞（LECs）中Ca2+稳态的改变如何与不同类型的白内障（皮质性或核性）相关联，以及白内障的进展（轻度或中度）如何影响Ca2+信号传导。我们系统地分析了人类LECs中细胞内和细胞间Ca2+信号传导的不同方面，这些细胞附着于白内障手术中获取的手术分离晶状体囊（LC）。我们通过倒置显微镜捕获Fura-2荧光，监测乙酰胆碱刺激后细胞内Ca2+浓度的时空变化。在分析中，我们比较了单个细胞中Ca2+信号的特征、同步激活、时空分组以及LECs之间细胞间通讯的性质。后者通过复杂网络理论方法进行评估。我们的结果指出，在单个细胞水平上，比较信号特征时，无论是白内障的类型还是阶段，均无显著差异。另一方面，尽管囊间存在变异性，但在多细胞水平上观察到明显差异。与更严重白内障相关的LCs对刺激的集体反应较慢，具有相似信号特征的LECs的时空聚类不太明显。发现重建的细胞间网络比与轻度白内障相关的LCs更稀疏、更隔离。此外，我们表明自发活跃的LECs通常在局部群体中运作，其Ca2+活性相当一致。还发现自发活动的存在会影响单个细胞的刺激Ca2+反应。我们的研究结果表明，白内障进展会导致细胞间信号传导受损，从而表明LECs中Ca2+信号改变在白内障发生过程中的功能重要性。
