The Expression Alteration of BC1 RNA and its Interaction with Eukaryotic Translation Initiation Factor eIF4A Post-Status Epilepticus

Abnormal dendritic sprouting and synaptic remodelling are important pathological features of temporal lobe epilepsy. BC1 RNA is a translation repressor involved in the regulation of the dendritic protein synthesis and mRNA transport, which is essential for dendritic development and plasticity. The expression alteration of BC1 RNA in the pilocarpine induced epilepsy model remains unknown. It is unclear if the interactions between BC1 RNA and eukaryotic initiation factor 4A (eIF4A) exists in this model. The purpose of this study was to investigate the expression changes of BC1 RNA and its interactions with eIF4A post-status epilepticus (SE). Chloride lithium and pilocarpine were used to induce the SE rat model. Either a whole brain or hippocampus tissues were collected at different time points after SE. The expression patterns of BC1 was detected by qPCR and in situ hybridization. The levels of eIF4AI/II protein expression were analyzed via western blotting and immunohistochemistry. The BC1 RNA-eIF4AI/II interaction was determined by electrophoretic mobility shift assay (EMSA). We found that the BC1 RNA levels decreased in hippocampus 3d, 1w and 2w post-SE before the levels recovered. The eIF4AI/II began to rise 3d post-SE and reached the maximum level 1w post-SE. After 1w post-SE the levels decreased in the hippocampal CA1, CA3 and DG subregions. EMSA analysis showed that BC1 RNA specifically interacted with the eIF4AI/II. The BC1 RNA-eIF4AI/II complex reduced to the lowest level 1w post-SE. Our results suggested that BC1 has a negative regulatory correlation with eIF4AI/II, where BC1 RNA could be involved in epileptogenesis by regulating dendritic protein synthesis.     

Aucubin Alleviates Seizures Activity in Li-Pilocarpine-Induced Epileptic Mice: Involvement of Inhibition of Neuroinflammation and Regulation of Neurotransmission

Neuroinflammation and imbalance of neurotransmitters play pivotal roles in seizures and epileptogenesis. Aucubin (AU) is an iridoid glycoside derived from Eucommia ulmoides that possesses anti-inflammatory and neuroprotective effects. However, the anti-seizure effects of AU have not been reported so far. The present study was designed to investigate the effects of AU on pilocarpine (PILO) induced seizures and its role in the regulation of neuroinflammation and neurotransmission. We found that AU reduced seizure intensity and prolonged the latency of seizures. AU significantly attenuated the activation of astrocytes and microglia and reduced the levels of interleukine-1 beta (IL-1β), high mobility group box 1 (HMGB1), tumor necrosis factor-α (TNF-α). Furthermore, the contents of γ-aminobutyric acid (GABA) were increased while the levels of glutamate were decreased in the hippocampus with AU treatment. The expression of γ-aminobutyric acid type A receptor subunit α1 (GABA_ARα1) and glutamate transporter-1 (GLT-1) protein were up-regulated in AU treatment group. However, AU had no significant effect on N-methyl-d-aspartate receptor subunit 2B (NR2B) expression in status epilepticus (SE). In conclusion, our findings provide the first evidence that AU can exert anti-seizure effects by attenuating gliosis and regulating neurotransmission. The results suggest that AU may be developed as a drug candidate for the treatment of epilepsy.