Department of Ultrasound, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Department of Neurology, The People's Hospital of Rongchang, Chongqing, China.
Epilepsy Res. 2022 May;182:106915. doi: 10.1016/j.eplepsyres.2022.106915. Epub 2022 Mar 30.
Epilepsy is a severe neurological and mental disorder, and not all patients adequately respond to the current treatments. Dynamin 1 plays a key role in synaptic endocytosis and the modulation of neurological function.
Cultured hippocampal neurons were used in the study. First, the viability of neurons was determined by the CCK-8 assay after culturing in magnesium-free medium, DMSO, dynasore (dynamin agonist), and PIP2 (dynamin antagonist). Then, the effect of dynasore on seizure activity was evaluated. Next, we tested the levels of phospho-dynamin 1/total dynamin 1 and dynamin 1 mRNA in the control group and four epilepsy groups. Moreover, the uptake of tetramethylrhodamine-dextran in the different groups was measured.
Dephospho-dynamin 1 expression was significantly increased in hyperexcitable neurons, while there was no change in total dynamin 1 level. The level of dephospho-dynamin 1 in hyperexcitable neurons was reduced when cultured with dynasore but increased with PIP2 treatment. Activity-dependent bulk endocytosis (ADBE) was upregulated in hyperexcitable neurons. Along with a decrease in dephospho-dynamin 1 level, ADBE was also downregulated with dynasore treatment, while PIP2 did not affect ABDE. The close link between the dephosphorylation status of dynamin 1 and ADBE suggests that ADBE activation depends on dynamin 1 dephosphorylation.
Dephospho-dynamin 1 triggers ADBE to meet the requirements of high-frequency discharges during epileptic seizures.
癫痫是一种严重的神经和精神疾病，并非所有患者对现有治疗均有充分反应。动力蛋白 1（Dynamin 1）在突触内吞作用和神经功能调节中发挥关键作用。
本研究采用培养的海马神经元。首先，在无镁培养基、DMSO、dynasore（动力蛋白激动剂）和 PIP2（动力蛋白拮抗剂）中培养神经元后，通过 CCK-8 测定法确定神经元活力。然后，评估 dynasore 对癫痫发作活动的影响。接下来，我们检测了对照组和四组癫痫模型中磷酸化动力蛋白 1/总动力蛋白 1和动力蛋白 1mRNA 的水平。此外，还测量了各组中四甲基罗丹明-葡聚糖的摄取量。
过度兴奋神经元中的去磷酸化动力蛋白 1表达明显增加，而总动力蛋白 1水平没有变化。用 dynasore 培养时，过度兴奋神经元中的去磷酸化动力蛋白 1水平降低，而用 PIP2 处理时则增加。活性依赖性大胞饮（ADBE）在过度兴奋神经元中上调。随着去磷酸化动力蛋白 1水平的降低，dynasore 处理也使 ADBE 下调，而 PIP2 则不影响 ADBE。动力蛋白 1去磷酸化状态与 ADBE 之间的紧密联系表明，ADBE 的激活取决于动力蛋白 1 的去磷酸化。
去磷酸化动力蛋白 1触发 ADBE 以满足癫痫发作期间高频放电的要求。
