Altered Norbin Expression in Patients with Epilepsy and a Rat Model.

Norbin is widely distributed in neuronal tissues, is a regulator of Ca2+/calmodulin-dependent protein kinase II (CaMKII) phosphorylation. Norbin is also an important endogenous modulator of metabotropic glutamate receptor 5 (mGluR5) signaling, and nervous system-specific homozygous gene disruptions, result in epileptic seizures. In this study, we aimed to investigate norbin expression patterns in epilepsy and to elucidate the relationships between norbin and mGluR5 and p-CaMKII in epilepsy. Double-immunolabeling, immunohistochemistry and immunoblotting studies showed that norbin was downregulated in the temporal neocortex of patients with temporal lobe epilepsy (TLE) compared with control subjects. Moreover, in a rat model of lithium chloride-pilocarpine-induced epilepsy, norbin expression began to decrease at 6 h after the onset of status epilepticus and remained at a low level until 60 days. In addition, p-CaMKII expression was significantly increased in both patients with TLE and in animal model. Norbin and mGluR5 were found to be co-expressed in neurons of epileptic tissues. Finally, norbin over-expression facilitated by injections of adeno-associated viral vector into the rat hippocampus increased latency and survival in the lithium chloride-pilocarpine model. Thus, our results indicate norbin participates in the pathogenesis of epilepsy, perhaps by modulating mGluR5 signaling, regulating CaMKII phosphorylation, and may exert antiepileptic effects.

Synthetic Isoliquiritigenin Inhibits Human Tongue Squamous Carcinoma Cells through Its Antioxidant Mechanism.

Isoliquiritigenin (ISL), a natural antioxidant, has antitumor activity in different types of cancer cells. However the antitumor effect of ISL on human tongue squamous carcinoma cells (TSCC) is not clear. Here we aimed to investigate the effects of synthetic isoliquiritigenin (S-ISL) on TSCC and elucidate the underlying mechanisms. S-ISL was synthesized and elucidated from its nuclear magnetic resonance spectrum and examined using high performance liquid chromatography. The effects of S-ISL on TSCC cells (Tca8113) were evaluated in relation to cell proliferation, apoptosis and adhesion, migration, and invasion using sulforhodamine B assay, fluorescence microscopy technique, flow cytometry (FCM) analysis, and Boyden chamber assay. The associated regulatory mechanisms were examined using FCM and fluorescence microscopy for intracellular reactive oxygen species (ROS) generation, Gelatin zymography assay for matrix metalloproteinase (MMP) activities, and Western blot for apoptosis regulatory proteins (Bcl-2 and Bax). Our data indicated that S-ISL inhibited Tca8113 cell proliferation, adhesion, migration, and invasion while promoting the cell apoptosis. Such effects were accompanied by downregulation of Bcl-2 and upregulation of Bax, reduction of MMP-2 and MMP-9 activities, and decreased ROS production. We conclude that S-ISL is a promising agent targeting TSCC through multiple anticancer effects, regulated by its antioxidant mechanism.

Plic-1, a new target in repressing epileptic seizure by regulation of GABAAR function in patients and a rat model of epilepsy.

Dysfunction of γ-aminobutyric acid A (GABAA) receptors (GABAARs) is a prominent factor affecting intractable epilepsy. Plic-1, an ubiquitin-like protein enriched in the inhibitory synapses connecting GABAARs and the ubiquitin protease system (UPS), plays a key role in the modification of GABAAR functions. However, the relationship between Plic-1 and epileptogenesis is not known. In the present study, we aimed to investigate Plic-1 levels in patients with temporal lobe epilepsy, as well as the role of Plic-1 in regulating onset and progression of epilepsy in animal models. We found that Plic-1 expression was significantly decreased in patients with epilepsy as well as pilocarpine- and pentylenetetrazol (PTZ)-induced rat epileptic models. Intrahippocampal injection of the PePα peptide, which disrupts Plic-1 binding to GABAARs, significantly shortened the latency of seizure onset, and increased the seizure severity and duration in these two epileptic models. Overexpressed Plic-1 through lentivirus transfection into a PTZ model resulted in a reduction in both seizure severity and generalized tonic-clonic seizure duration. Whole-cell clamp recordings revealed that the PePα peptide decreased miniature inhibitory postsynaptic currents (mIPSCs) whereas overexpressed Plic-1 increased mIPSCs in the pyramidal neurons of the hippocampus. These effects can be blocked by picrotoxin, a GABAAR inhibitor. Our results indicate that Plic-1 plays an important role in managing epileptic seizures by enhancing seizure inhibition through regulation of GABAARs at synaptic sites.

Altered expression of hypoxia-Inducible factor-1α participates in the epileptogenesis in animal models.

Although epilepsy is a common neurological disorder, its mechanism(s) are still not completely understood. Hypoxia can lead to neuronal cell death and angiogenesis, and the same mechanisms were also found in epilepsy. Hypoxia-inducible factor-1α (HIF-1α) is an important transcription protein that regulates gene expression in the brain and other tissues in response to decreases in oxygen availability. However, little is known regarding the expression of HIF-1α in the epileptic brain and whether HIF-1α interventions affect the epileptic process. The aims of this study are to investigate the expression profile of HIF-1α in rat models and to explore the role of HIF-1α in epilepsy. We performed Western blots and immunofluorescence in a lithium-pilocarpine rat epilepsy model. To determine the role of HIF-1α in epilepsy, we used the HIF-1α agonist DMOG and inhibitor KC7F2 to detect changes in the animal behavior in pentylenetetrazole (PTZ) and lithium-pilocarpine epilepsy models. The expression of HIF-1α was significantly increased after pilocarpine-induced status epilepticus. DMOG significantly prolonged the latent period in the PTZ kindling model and decreased the rate of spontaneous recurrent seizures during the chronic stage in the lithium-pilocarpine model. Conversely, the inhibitor KC7F2 produced an opposite behavioral change. Interestingly, both KC7F2 and DMOG had no effect on the acute stage of pilocarpine model and PTZ convulsive model. Our study suggests that upregulated HIF-1α may be involved in the process of epileptogenesis but not in the acute stage of epilepsy. The modulation of HIF-1α may offer a novel therapeutic target in epilepsy.

QPEEG analysis of the effects of sodium valproate on adult Chinese patients with generalized tonic-clonic seizures.

Objectives EEG effects of the sustained-release form of sodium valproate (SR-VPA) are unknown, although it is widely used in Chinese patients with generalized tonicclonic seizures (GTCS). Methods Fourteen newly diagnosed, untreated GTCS patients were recruited and treated with SR-VPA. Waking EEG was recorded and analyzed by way of quantitative pharmaco-electroencephalogram (QPEEG) analysis during the three-month follow-up. Results There was a statistically significant decrease in the absolute power of the delta band (P < 0.05), theta band (P < 0.03) and partial alpha-1 band (p < 0.05) with treatment compared to before treatment, while there was no significantly different absolute power between one-month and three-months after treatment. There was a strong correlation between the decrease in absolute power and the degree of the initial abnormality in all frequency bands. Two of 14 patients experienced seizures during the second month after initiation of SR-VPA therapy. Conclusions SR-VPA selectively decreased the activity of the abnormal EEG synchronization in a use-dependent manner. The reduced theta, delta, and partial alpha-1 absolute power may reflect or confirm the efficacy of SR-VPA on patients with GTCS.