Department of Anatomy, Medical Theoretical Center, TU-Dresden, 01069 Dresden, Germany.
Center and Department of Biomedical Engineering/Unicamp, 13083-872 Campinas-SP, Brazil.
Front Biosci (Landmark Ed). 2022 Sep 29;27(9):273. doi: 10.31083/j.fbl2709273.
Studies show that electric fields are used as therapy during nerve and tissue injuries along with trans-retinal stimulation. However, cellular and molecular changes induced by such treatments remain largely unknown especially in retinal photoreceptor cells. studies show that direct current electric fields (dcEF) were known to influence cell division, polarity, shape, and motility. Here we could characterize for the first time the reactions of 661W, a retinal cone photoreceptor especially regarding organelle polarization, membrane polarization of mitochondria, O2 consumption, ATP/ADP ratio and gene expression.
The 661W cells were stimulated with a constant dcEF of field strength 5 V/cm during 30 min or 5 h depending on the parameters studied.
In response to dcEF, the cells aligned perpendicular to the field by forming a leading edge with extended membrane protrusions towards the cathode. Using immunofluorescence and live cell imaging, we show that the cell membrane depolarized at the cathodal side. The microtubules spread into the direction of migration. Also, the microtubule organization center re-oriented into this direction. Concomitantly with the microtubules, actin filaments reorganized in an asymmetrical fashion mainly at the cathodal side. The Golgi apparatus, which is involved in many steps of actin synthesis, moved to the cathodal side. In the last 2 h of the 5 h experiment, microtubules positioned themselves at the rear (anodal side), like the nucleus. The averaged displacement of the whole cells under dcEF was 155% of control for 3 V/cm and 235% for 5 V/cm. The average speed increased by 142% and 243% respectively. Inside the cells mitochondria moved to the cathodal side, where the energy consuming producing processes take place. In this line, we measured an increase in ATP production and O2 consumption. Mitochondrial calcium was found more on the anodal side, at the site of the nucleus with its calcium delivering endoplasmic reticulum. In addition, oxymetry studies reveal an increased ATP synthesis by 115.2% and oxygen consumption by 113.3% 3 h after dcEF stimulation. An analysis of differentially expressed genes by RNA sequencing revealed an upregulation of genes involved in cellular movement, cell to cell and intracellular signaling, molecular transport, assembly and organization.
The mechanisms found can enhance our understanding regarding the beneficial effects of EF treatment in retinal diseases.
研究表明，电场在神经和组织损伤以及视网膜刺激时被用作治疗手段。然而，这种治疗方法所引起的细胞和分子变化在很大程度上仍然未知，尤其是在视网膜光感受器细胞中。研究表明，直流电场（dcEF）已知会影响细胞分裂、极性、形状和运动。在这里，我们首次能够描述 661W（一种视网膜锥状光感受器）的反应，特别是关于细胞器极化、线粒体膜极化、O2 消耗、ATP/ADP 比和基因表达。
根据研究的参数，将 661W 细胞用强度为 5 V/cm 的恒定 dcEF 刺激 30 分钟或 5 小时。
对 dcEF 的反应是，细胞通过在阴极侧形成延伸的膜突起来垂直于电场排列，形成一个前沿。通过免疫荧光和活细胞成像，我们显示细胞在阴极侧去极化。微管向迁移方向扩散。此外，微管组织中心也向这个方向重新定向。与微管一起，肌动蛋白丝以不对称的方式重新排列，主要在阴极侧。高尔基体参与肌动蛋白合成的许多步骤，向阴极侧移动。在 5 小时实验的最后 2 小时，微管位于后部（阳极侧），就像细胞核一样。在 dcEF 下，整个细胞的平均位移为对照的 155%（3 V/cm）和 235%（5 V/cm）。平均速度分别增加了 142%和 243%。细胞内的线粒体向阴极侧移动，那里发生能量消耗的产生过程。在这方面，我们测量到 ATP 生成和 O2 消耗增加。线粒体钙位于阳极侧，在细胞核处，其钙输送内质网。此外，氧测量研究表明，dcEF 刺激 3 小时后，ATP 合成增加 115.2%，氧气消耗增加 113.3%。通过 RNA 测序对差异表达基因的分析显示，参与细胞运动、细胞间和细胞内信号转导、分子运输、组装和组织的基因上调。
发现的机制可以增强我们对 EF 治疗在视网膜疾病中的有益效果的理解。
