The strategy of using electrical stimulation (ES) to promote the neural differentiation and regeneration of injured nerves is proven feasible. Study of the possible molecular mechanisms in relation to this ES promotion effect should be helpful for understanding the phenomenon. In this study, it was identified that the neuronal differentiation of PC12 cells was enhanced when the electric field intensity was in the range of 30-80 mV/mm, and a lower or higher electric-field intensity displayed inferior effects. Under ES, however, levels of intracellular reactive oxygen species (ROS), intracellular Ca2+ dynamics, and expression of TREK-1 were measured as being gradually increasing alongside higher electric-field intensity. In trying to understand the relationship between the ES enhancement on differentiation and these variations in cell activities, parallel experiments were conducted by introducing exogeneous H2O2 into culture systems at different concentrations. Similarly, the effects of H2O2 concentration on the neuronal differentiation of PC12 cells, intracellular ROS and Ca2+ levels, and TREK-1 expression were systematically characterized. In comparative studies, it was found in two cases that ES of 50 mV/mm for 2 h/day and H2O2 of 5 μM in culture medium shared comparable results for intracellular ROS and Ca2+ levels and TREK-1 expression. Higher H2O2 concentrations (e.g., 10 and 20 μM) demonstrated adverse effects on cell differentiation and caused DNA damage. A stronger ES (e.g., 100 mV/mm), being associated with a higher intracellular ROS level, also resulted in weaker enhancement of the neuronal differentiation of PC12 cells. These facts suggested that the intracellular ROS generated under ES might be an intermediate signal transducer involved in cascade reactions relative to cell differentiation.

中文翻译：

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不同电场强度电刺激PC12细胞分化调控的研究。

事实证明，使用电刺激（ES）促进受损神经的神经分化和再生的策略是可行的。研究与这种ES促进作用有关的可能的分子机制应该有助于理解该现象。在这项研究中，已确定当电场强度在30-80 mV / mm的范围内时，PC12细胞的神经元分化会增强，而较低或较高的电场强度则显示出较差的效果。然而，在ES条件下，细胞内活性氧（ROS），细胞内Ca2 +动力学和TREK-1的表达水平随着电场强度的增加而逐渐增加。在试图了解ES对分化的增强与细胞活性的这些变化之间的关系时，通过将不同浓度的外源H2O2引入培养系统进行平行实验。同样，系统地表征了H2O2浓度对PC12细胞神经元分化，细胞内ROS和Ca2 +水平以及TREK-1表达的影响。在比较研究中，发现在两个案例中，培养基中2 h / day的ES为50 mV / mm，培养基中H2O2为5μM，在细胞内ROS和Ca2 +水平以及TREK-1表达方面具有可比的结果。较高的H2O2浓度（例如10和20μM）显示出对细胞分化的不利影响并引起DNA损伤。与较高的细胞内ROS水平相关的较强的ES（例如100mV / mm）也导致PC12细胞的神经元分化的增强较弱。