The hyperpolarization-activated cyclic nucleotide-gated cation channel (HCN1) is predominantly located in key regions associated with epilepsy, such as the neocortex and hippocampus. Under normal physiological conditions, HCN1 plays a crucial role in the excitatory and inhibitory regulation of neuronal networks. In temporal lobe epilepsy, the expression of HCN1 is decreased in the hippocampi of both animal models and patients. However, whether HCN1 expression changes during epileptogenesis preceding spontaneous seizures remains unclear. The aim of this study was to determine whether the expression of HCN1 is altered during the epileptic prodromal phase, thereby providing evidence for its role in epileptogenesis. We utilized a cobalt wire-induced rat epilepsy model to observe changes in HCN1 during epileptogenesis and epilepsy. Additionally, we also compared HCN1 alterations in epileptogenic tissues between cobalt wire- and pilocarpine-induced epilepsy rat models. Long-term video EEG recordings were used to confirm seizures development. Transcriptional changes, translation, and distribution of HCN1 were assessed using high-throughput transcriptome sequencing, total protein extraction, membrane and cytoplasmic protein fractionation, western blotting, immunohistochemistry, and immunofluorescence techniques. In the cobalt wire-induced rat epilepsy model during the epileptogenesis phase, total mRNA and protein levels were downregulated. Specifically, the membrane expression of HCN1 was decreased, whereas cytoplasmic HCN1 expression showed no significant change. The distribution of HCN1 in the distal dendrites of neurons decreased. During the epilepsy period, similar HCN1 alterations were observed in the neocortex of rats with cobalt wire-induced epilepsy and hippocampus of rats with lithium pilocarpine-induced epilepsy, including downregulation of mRNA levels, decreased total protein expression, decreased membrane expression, and decreased distal dendrite expression. Alterations in HCN1 expression and distribution are involved in epileptogenesis beyond their association with seizure occurrence. Similarities in HCN1 alterations observed in epileptogenesis-related tissues from different models suggest a shared pathophysiological pathway in epileptogenesis involving HCN1 dysregulation. Therefore, the upregulation of HCN1 expression in neurons, maintenance of the HCN1 membrane, and distal dendrite distribution in neurons may represent promising disease-modifying strategies in epilepsy.

中文翻译：

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大鼠癫痫发生过程中 HCN1 表达和分布的变化


超极化激活的环核苷酸门控阳离子通道（HCN1）主要位于与癫痫相关的关键区域，例如新皮质和海马体。在正常生理条件下，HCN1在神经元网络的兴奋性和抑制性调节中发挥着至关重要的作用。在颞叶癫痫中，动物模型和患者海马中 HCN1 的表达均降低。然而，HCN1 表达在自发性癫痫发作之前的癫痫发生过程中是否发生变化仍不清楚。本研究的目的是确定HCN1的表达在癫痫前驱期是否发生改变，从而为其在癫痫发生中的作用提供证据。我们利用钴丝诱导的大鼠癫痫模型来观察癫痫发生和癫痫过程中HCN1的变化。此外，我们还比较了钴丝和毛果芸香碱诱导的癫痫大鼠模型致癫痫组织中 HCN1 的变化。长期视频脑电图记录用于确认癫痫发作的发展。使用高通量转录组测序、总蛋白提取、膜和细胞质蛋白分级分离、蛋白质印迹、免疫组织化学和免疫荧光技术评估 HCN1 的转录变化、翻译和分布。在钴丝诱导的大鼠癫痫模型中，在癫痫发生阶段，总 mRNA 和蛋白质水平下调。具体来说，HCN1的膜表达降低，而细胞质HCN1表达没有显着变化。 HCN1在神经元远端树突中的分布减少。 在癫痫期间，在钴丝诱发癫痫大鼠的新皮质和锂毛果芸香碱诱发癫痫大鼠的海马中观察到类似的HCN1改变，包括mRNA水平下调、总蛋白表达减少、膜表达减少和远端减少。树突表达。 HCN1 表达和分布的改变除了与癫痫发作的发生相关之外，还与癫痫发生有关。在不同模型的癫痫发生相关组织中观察到的 HCN1 改变的相似性表明，涉及 HCN1 失调的癫痫发生存在共同的病理生理学途径。因此，神经元中 HCN1 表达的上调、HCN1 膜的维持以及神经元中远端树突的分布可能代表了有希望的癫痫疾病缓解策略。