Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, 3584 CG Utrecht, The Netherlands.
Department of Physiology and Medical Physics.
J Neurosci. 2019 Jun 26;39(26):5064-5079. doi: 10.1523/JNEUROSCI.3014-18.2019. Epub 2019 Apr 23.
Mesial temporal lobe epilepsy (mTLE) is a chronic neurological disease characterized by recurrent seizures. The antiepileptic drugs currently available to treat mTLE are ineffective in one-third of patients and lack disease-modifying effects. miRNAs, a class of small noncoding RNAs which control gene expression at the post-transcriptional level, play a key role in the pathogenesis of mTLE and other epilepsies. Although manipulation of miRNAs at acute stages has been reported to reduce subsequent spontaneous seizures, it is uncertain whether targeting miRNAs at chronic stages of mTLE can also reduce seizures. Furthermore, the functional role and downstream targets of most epilepsy-associated miRNAs remain poorly understood. Here, we show that is selectively upregulated within neurons in epileptic brain and report that targeting using antagomirs after onset of spontaneous recurrent seizures can reduce seizure activity at the chronic stage of experimental mTLE in male mice. Further, by using an unbiased approach combining immunoprecipitation and RNA sequencing, we identify several novel neuronal targets of , including Mef2 proteins are key regulators of excitatory synapse density. Mef2a and show reciprocal expression regulation in human (of both sexes) and experimental TLE, and regulates dendritic spine number and type through Mef2. Together, our data show that is target for reducing seizure activity in chronic epilepsy, and that deregulation of in epilepsy may alter expression and thereby affect synaptic function and plasticity. miRNAs are post-transcriptional regulators of gene expression with roles in the pathogenesis of epilepsy. However, the precise mechanism of action and therapeutic potential of most epilepsy-associated miRNAs remain poorly understood. Our study reveals dramatic upregulation of the key neuronal miRNA in both experimental and human mesial temporal lobe epilepsy. Silencing in experimental temporal lobe epilepsy reduces seizure activity at the spontaneous recurrent seizure stage. These data support the exciting possibility that miRNAs can be targeted to combat seizures after spontaneous seizure activity has been established. Further, by using unbiased approaches novel neuronal targets of , including members of the Mef2 protein family, are identified that begin to explain how deregulation of may contribute to epilepsy.
内侧颞叶癫痫（mTLE）是一种慢性神经系统疾病，其特征是反复发作。目前用于治疗 mTLE 的抗癫痫药物在三分之一的患者中无效，并且缺乏疾病修饰作用。miRNA 是一类小的非编码 RNA，可在转录后水平控制基因表达，在 mTLE 和其他癫痫的发病机制中发挥关键作用。尽管已有报道称在急性阶段操纵 miRNA 可以减少随后的自发性癫痫发作，但尚不确定针对 mTLE 的慢性阶段的 miRNA 是否也可以减少癫痫发作。此外，大多数与癫痫相关的 miRNA 的功能作用和下游靶标仍知之甚少。在这里，我们显示在癫痫大脑中的神经元中选择性地上调，并报告说在自发性复发性癫痫发作后使用反义寡核苷酸靶向可以减少雄性小鼠实验性 mTLE 的慢性阶段的癫痫发作活动。此外，通过使用结合免疫沉淀和 RNA 测序的无偏方法，我们鉴定出几个新的神经元靶标，包括 Mef2 蛋白是兴奋性突触密度的关键调节因子。Mef2a 和 在人类（两性）和实验性 TLE 中表现出相互的表达调控，并且通过 Mef2 调节树突棘数量和类型。总之，我们的数据表明 是减少慢性癫痫中癫痫发作活动的靶标，并且癫痫症中 的失调可能改变 的表达，从而影响突触功能和可塑性。miRNA 是基因表达的转录后调节剂，在癫痫的发病机制中起作用。然而，大多数与癫痫相关的 miRNA 的精确作用机制和治疗潜力仍知之甚少。我们的研究揭示了关键神经元 miRNA 在实验性和人类内侧颞叶癫痫中均显著上调。沉默 在实验性颞叶癫痫中减少自发性癫痫发作阶段的癫痫发作活动。这些数据支持激动人心的可能性，即可以针对 miRNA 进行靶向治疗以对抗自发性癫痫发作活动建立后的癫痫发作。此外，通过使用无偏方法，鉴定出包括 Mef2 蛋白家族成员在内的 的新神经元靶标，开始解释 的失调如何导致癫痫。
