-
Journal of Neuroinflammation Jan 2024Ferroptosis is an iron-dependent cell death mechanism involving the accumulation of lipid peroxides. As a critical regulator, glutathione peroxidase 4 (GPX4) has been...
Ferroptosis is an iron-dependent cell death mechanism involving the accumulation of lipid peroxides. As a critical regulator, glutathione peroxidase 4 (GPX4) has been demonstrated to be downregulated in epilepsy. However, the mechanism of ferroptosis in epilepsy remains unclear. In this study, bioinformatics analysis, analysis of epilepsy patient blood samples and cell and mouse experiments revealed strong associations among epilepsy, ferroptosis, microRNA-211-5p and purinergic receptor P2X 7 (P2RX7). P2RX7 is a nonselective ligand-gated homotrimeric cation channel, and its activation mainly increases neuronal activity during epileptic seizures. In our study, the upregulation of P2RX7 in epilepsy was attributed to the downregulation of microRNA (miR)-211-5p. Furthermore, P2RX7 has been found to regulate GPX4/HO-1 by alleviating lipid peroxidation induced by suppression of the MAPK/ERK signaling pathway in murine models. The dynamic decrease in miR-211-5p expression induces hypersynchronization and both nonconvulsive and convulsive seizures, and forebrain miR-211-5p suppression exacerbates long-lasting pentylenetetrazole-induced seizures. Additionally, in this study, induction of miR-211-5p expression or genetic-silencing of P2RX7 significantly reduced the seizure score and duration in murine models through the abovementioned pathways. These results suggest that the miR-211-5p/P2RX7 axis is a novel target for suppressing both ferroptosis and epilepsy.
Topics: Humans; Animals; Mice; Ferroptosis; Epilepsy; Oxidative Stress; Seizures; MicroRNAs; Receptors, Purinergic P2X7
PubMed: 38191407
DOI: 10.1186/s12974-023-03009-z -
Biomedicine & Pharmacotherapy =... Dec 2023A series of 3-aminopyrrolidine-2,5-dione derivatives was synthesized and tested for anticonvulsant activity. Succinimide derivatives were obtained from a simple...
A series of 3-aminopyrrolidine-2,5-dione derivatives was synthesized and tested for anticonvulsant activity. Succinimide derivatives were obtained from a simple solvent-based reaction and a mechanochemical aza-Michael reaction of maleimide or its N-substituted derivatives with selected amines. The structure of the compounds was confirmed by spectroscopic methods (NMR, FT-IR, HPLC, ESI-MS, EA and XRD for four compounds). The cytotoxic activity of the succinimide derivatives was evaluated using HepG2 cells for hepatocytotoxicity and SH-SY5Y cells for neurocytotoxicity. None of the studied compounds showed hepatocytotoxicity and two showed neurocytotoxicity. Initial anticonvulsant screening was performed in mice using the psychomotor seizure test (6 Hz, 32 mA). The selected compounds were evaluated in the following acute models of epilepsy: the maximal electroshock test, psychomotor seizure test (6 Hz, 44 mA), subcutaneous pentylenetetrazole seizure test, and acute neurotoxicity (rotarod test). The most active compound 3-((4-chlorophenyl)amino)pyrrolidine-2,5-dione revealed antiseizure activity in all seizure models (including pharmacoresistant seizures) and showed better median effective doses (ED) and protective index values than the reference compound, ethosuximide. Furthermore, 3-(benzylamino)pyrrolidine-2,5-dione and 3-(phenylamino)pyrrolidine-2,5-dione exhibited antiseizure activity in the 6 Hz and MES tests, and 3-(butylamino)-1-phenylpyrrolidine-2,5-dione and 3-(benzylamino)-1-phenylpyrrolidine-2,5-dione exhibited antiseizure activity in the 6 Hz test. All active compounds demonstrated low in vivo neurotoxicity in the rotarod test and yielded favourable protective indices.
Topics: Humans; Mice; Animals; Anticonvulsants; Spectroscopy, Fourier Transform Infrared; Neuroblastoma; Seizures; Ethosuximide; Pentylenetetrazole; Structure-Activity Relationship; Molecular Structure
PubMed: 37879208
DOI: 10.1016/j.biopha.2023.115749 -
Translational Research : the Journal of... Oct 2023The CLU rs11136000C mutation (CLU) is the third most common risk factor for Alzheimer's disease (AD). However, the mechanism by which CLU leads to abnormal GABAergic...
The CLU rs11136000C mutation (CLU) is the third most common risk factor for Alzheimer's disease (AD). However, the mechanism by which CLU leads to abnormal GABAergic signaling in AD is unclear. To address this question, this study establishes the first chimeric mouse model of CLU AD. Examination of grafted CLU medial ganglionic eminence progenitors (CLU hiMGEs) revealed increased GAD65/67 and a high frequency of spontaneous releasing events. CLU hiMGEs also impaired cognition in chimeric mice and caused AD-related pathologies. The expression of GABA A receptor, subunit alpha 2 (Gabrα2) was higher in chimeric mice. Interestingly, cognitive impairment in chimeric mice was reversed by treatment with pentylenetetrazole, which is a GABA A receptor inhibitor. Taken together, these findings shed light on the pathogenesis of CLU AD using a novel humanized animal model and suggest sphingolipid signaling over-activation as a potential mechanism of GABAergic signaling disorder.
Topics: Animals; Mice; Alzheimer Disease; Clusterin; Cognitive Dysfunction; Disease Models, Animal; Mutation; Receptors, GABA-A; Risk Factors; Humans
PubMed: 37211336
DOI: 10.1016/j.trsl.2023.05.003 -
International Journal of Molecular... Sep 2023Epilepsy is a chronic condition characterized by recurrent spontaneous seizures. The interaction between astrocytes and neurons has been suggested to play a role in the...
Epilepsy is a chronic condition characterized by recurrent spontaneous seizures. The interaction between astrocytes and neurons has been suggested to play a role in the abnormal neuronal activity observed in epilepsy. However, the exact way astrocytes influence neuronal activity in the epileptogenic brain remains unclear. Here, using the PTZ-induced kindling mouse model, we evaluated the interaction between astrocyte and synaptic function by measuring astrocytic Ca activity, neuronal excitability, and the excitatory/inhibitory balance in the hippocampus. Compared to control mice, hippocampal slices from PTZ-kindled mice displayed an increase in glial fibrillary acidic protein (GFAP) levels and an abnormal pattern of intracellular Ca-oscillations, characterized by an increased frequency of prolonged spontaneous transients. PTZ-kindled hippocampal slices also showed an increase in the E/I ratio towards excitation, likely resulting from an augmented release probability of excitatory inputs without affecting inhibitory synapses. Notably, the alterations in the release probability seen in PTZ-kindled slices can be recovered by reducing astrocyte hyperactivity with the reversible toxin fluorocitrate. This suggests that astroglial hyper-reactivity enhances excitatory synaptic transmission, thereby impacting the E/I balance in the hippocampus. Altogether, our findings support the notion that abnormal astrocyte-neuron interactions are pivotal mechanisms in epileptogenesis.
Topics: Mice; Animals; Pentylenetetrazole; Astrocytes; Epilepsy; Kindling, Neurologic; Seizures; Hippocampus
PubMed: 37833953
DOI: 10.3390/ijms241914506 -
BioRxiv : the Preprint Server For... Nov 2023Brain somatic variants in are associated with clinically drug-resistant epilepsy and developmental brain malformations, including mild malformation of cortical...
Brain somatic variants in are associated with clinically drug-resistant epilepsy and developmental brain malformations, including mild malformation of cortical development with oligodendroglial hyperplasia in epilepsy (MOGHE). encodes a uridine diphosphate galactose translocator that is essential for protein glycosylation; however, the neurodevelopmental mechanisms by which disruption leads to clinical and histopathological features remain unspecified. We hypothesized that focal knockout (KO) or knockdown (KD) of in the developing mouse cortex would disrupt cerebral cortical development through altered neuronal migration and cause changes in network excitability. We used electroporation (IUE) to introduce CRISPR/Cas9 and targeted guide RNAs or short-hairpin RNAs to achieve KO or KD, respectively, during early corticogenesis. Following KO or KD, we observed disrupted radial migration of transfected neurons evidenced by heterotopic cells located in lower cortical layers and in the sub-cortical white matter. KO in neurons did not induce changes in oligodendrocyte number, suggesting that the oligodendroglial hyperplasia observed in MOGHE originates from distinct cell autonomous effects. Spontaneous seizures were not observed, but intracranial EEG recordings after focal KO showed a reduced seizure threshold following pentylenetetrazol injection. These results demonstrate that KO or KD disrupts corticogenesis through altered neuronal migration.
PubMed: 38077069
DOI: 10.1101/2023.11.29.569243 -
CNS Neuroscience & Therapeutics Apr 2024Although programmed cell death protein 1 (PD-1) typically serves as a target for immunotherapies, a few recent studies have found that PD-1 is expressed in the nervous...
AIMS
Although programmed cell death protein 1 (PD-1) typically serves as a target for immunotherapies, a few recent studies have found that PD-1 is expressed in the nervous system and that neuronal PD-1 might play a crucial role in regulating neuronal excitability. However, whether brain-localized PD-1 is involved in seizures and epileptogenesis is still unknown and worthy of in-depth exploration.
METHODS
The existence of PD-1 in human neurons was confirmed by immunohistochemistry, and PD-1 expression levels were measured by real-time quantitative PCR (RT-qPCR) and western blotting. Chemoconvulsants, pentylenetetrazol (PTZ) and cyclothiazide (CTZ), were applied for the establishment of in vivo (rodents) and in vitro (primary hippocampal neurons) models of seizure, respectively. SHR-1210 (a PD-1 monoclonal antibody) and sodium stibogluconate (SSG, a validated inhibitor of SH2-containing protein tyrosine phosphatase-1 [SHP-1]) were administrated to investigate the impact of PD-1 pathway blockade on epileptic behaviors of rodents and epileptiform discharges of neurons. A miRNA strategy was applied to determine the impact of PD-1 knockdown on neuronal excitability. The electrical activities and sodium channel function of neurons were determined by whole-cell patch-clamp recordings. The interaction between PD-1 and α-6 subunit of human voltage-gated sodium channel (Nav1.6) was validated by performing co-immunostaining and co-immunoprecipitation (co-IP) experiments.
RESULTS
Our results reveal that PD-1 protein and mRNA levels were upregulated in lesion cores compared with perifocal tissues of surgically resected specimens from patients with intractable epilepsy. Furthermore, we show that anti-PD-1 treatment has anti-seizure effects both in vivo and in vitro. Then, we reveal that PD-1 blockade can alter the electrophysiological properties of sodium channels. Moreover, we reveal that PD-1 acts together with downstream SHP-1 to regulate sodium channel function and hence neuronal excitability. Further investigation suggests that there is a direct interaction between neuronal PD-1 and Nav1.6.
CONCLUSION
Our study reveals that neuronal PD-1 plays an important role in epilepsy and that anti-PD-1 treatment protects against seizures by suppressing sodium channel function, identifying anti-PD-1 treatment as a novel therapeutic strategy for epilepsy.
Topics: Humans; Epilepsy; Hippocampus; Programmed Cell Death 1 Receptor; Seizures; Sodium Channels; Antibodies, Monoclonal, Humanized; NAV1.6 Voltage-Gated Sodium Channel
PubMed: 37904722
DOI: 10.1111/cns.14504 -
PloS One 2023Phosphodiesterase 5 inhibitors (PDE5i) are the first line treatment for erectile dysfunction; however, several articles and case reports have shown central nervous...
BACKGROUND
Phosphodiesterase 5 inhibitors (PDE5i) are the first line treatment for erectile dysfunction; however, several articles and case reports have shown central nervous system effects, that can cause seizures in susceptible patients. This study aims to describe the changes caused by the use of Sildenafil and Tadalafil through the analysis of abnormalities expressed in the electrocorticogram (ECoG) of rats and evaluate the seizure threshold response and treatment of seizures with anticonvulsants.
MATERIALS AND METHODS
The study used 108 rats (Wistar). Before surgery for electrode placement in dura mater, the animals were randomly separated into 3 experiments for electrocorticogram analysis. Experiment 1: ECoG response to using PD5i (Sildenafil 20mg/kg and Tadalafil 2.6mg/kg p.o.). Experiment 2: ECoG response to the use of PD5i in association with Pentylenetetrazole (PTZ-30 mg/kg i.p.), a convulsive model. Experiment 3: ECoG response to anticonvulsant treatment (Phenytoin, Phenobarbital and Diazepam) of seizures induced by association IPDE5 + PTZ. All recordings were made thirty minutes after administration of the medication and analyzed for ten minutes, only once. We considered statistical significance level of *p<0.05, **p<0.01 and ***p < 0.001.
RESULTS
After administration of Sildenafil and Tadalafil, there were increases in the power of recordings in the frequency bands in oscillations in alpha (p = 0.0920) and beta (p = 0.602) when compared to the control group (p<0.001). After the use of Sildenafil and Tadalafil associated with PTZ, greater potency was observed in the recordings during seizures (p<0.001), however, the Sildenafil group showed greater potency when compared to Tadalafil (p<0.05). Phenobarbital and Diazepam showed a better response in controlling discharges triggered by the association between proconvulsant drugs.
CONCLUSIONS
PDE5i altered the ECoG recordings in the rats' motor cortexes, demonstrating cerebral asynchrony and potentiating the action of PTZ. These findings demonstrate that PDE5i can lower the seizure threshold.
Topics: Animals; Male; Rats; Anticonvulsants; Diazepam; Pentylenetetrazole; Phenobarbital; Phosphodiesterase 5 Inhibitors; Rats, Wistar; Seizures; Sildenafil Citrate; Tadalafil
PubMed: 38033148
DOI: 10.1371/journal.pone.0294754 -
International Immunopharmacology Mar 2024Epilepsy is a severe neurological disorder associated with substantial morbidity and mortality. Vanillin (Van) is a natural phenolic aldehyde with beneficial...
Ameliorative effects of vanillin against pentylenetetrazole-induced epilepsy and associated memory loss in mice: The role of Nrf2/HO-1/NQO1 and HMGB1/RAGE/TLR4/NFκB pathways.
BACKGROUND
Epilepsy is a severe neurological disorder associated with substantial morbidity and mortality. Vanillin (Van) is a natural phenolic aldehyde with beneficial pharmacological properties. This study investigated the neuroprotective effects of Van in epilepsy and elucidated its mechanism of action.
METHODS
Swiss albino mice were divided into the following five groups: "normal group", 0.9 % saline; "pentylenetetrazole (PTZ) group", intraperitoneal administration of 35 mg/kg PTZ on alternate days up to 42 days; and "PTZ + Van 20", "PTZ + Van 40", and "PTZ + sodium valproate (Val)" groups received PTZ injections in conjunction withVan 20 mg, Van 40 mg/kg, and Val 300 mg/kg, respectively. Behavioural tests and hippocampal histopathological analysis were performed in all groups. The Nrf2/HO-1/NQO1 and HMGB1/RAGE/TLR4/NFκB pathways, oxidative stress, neuro-inflammation, and apoptotic markers were analysed. Furthermore, brain acetylcholinesterase (AChE) activity and levels of dopamine (DA), gamma-aminobutyric acid GABA, and serotonin 5-HT were assessed.
RESULTS
Van prolonged seizure manifestations and improved electroencephalogram (EEG)criteriain conjunction with 100 mg/kg PTZ once daily. Van administration increased Nrf2/HO-1/NQO1 levels, with subsequent attenuation of malondialdehyde (MDA) and nitric oxide (NO) levels with elevated glutathione (GSH) levels and intensified superoxide dismutase (SOD) and catalase activities. Van reduced the gene and protein expression of HMGB1/RAGE/TLR4/NFκB and decreased the levels of inflammatory and apoptotic markers. In addition, Van reduced AChE activity, and elevated glial fibrillary acidic proteins (GFAP) increased neurotransmitter and brain-derived neurotrophic factors (BDNF).
CONCLUSION
By increasing Nrf2/HO-1/NQO1 levels and downregulating the HMGB1/RAGE/TLR4/ NFκB pathway, Van offered protection in PTZ-kindled mice with subsequent attenuation in lipid peroxidation, upregulation in antioxidant enzyme activities, and reduction in inflammation and apoptosis.
Topics: Mice; Animals; Pentylenetetrazole; NF-E2-Related Factor 2; Toll-Like Receptor 4; HMGB1 Protein; Acetylcholinesterase; Epilepsy; Antioxidants; Oxidative Stress; Memory Disorders; Glutathione; Inflammation; Benzaldehydes
PubMed: 38335655
DOI: 10.1016/j.intimp.2024.111657 -
Saudi Pharmaceutical Journal : SPJ :... Jan 2024Perampanel (PER), a novel 3rd-generation antiseizure drug that modulates altered post-synaptic glutamatergic storming by selectively inhibiting AMPA receptors, is...
Perampanel increases seizure threshold in pentylenetetrazole-kindled mice and improves behavioral dysfunctions by modifying mRNA expression levels of BDNF/TrkB and inflammatory markers.
Perampanel (PER), a novel 3rd-generation antiseizure drug that modulates altered post-synaptic glutamatergic storming by selectively inhibiting AMPA receptors, is recently approved to treat intractable forms of seizures. However, to date, presumably consequences of long-term PER therapy on the comorbid deleterious psychiatric disturbances and its correlation with neuroinflammatory parameters are not fully investigated in chronic models of epilepsy. Therefore, we investigated the real-time effect of PER on brain electroencephalographic (EEG) activity, behavioral alterations, redox balance, and relative mRNA expression in pentylenetetrazole (PTZ) induced kindling. Male BALB/c mice were pretreated with PER (0.125, 0.25, and 0.5 mg/kg) for 3 weeks and challenged with 11 injections of PTZ at the sub-threshold dose of 40 mg/kg every other day. vEEG from implanted cortical electrodes was monitored to elucidate seizure propagation and behavioral manifestations. Recorded EEG signals exhibited that PER 0.5 mg/kg pretreatment exceptionally impeded the onset of sharp epileptic spike-wave discharges and associated motor symptoms. Additionally, qEEG analysis showed that PER prevented alterations in absolute mean spectral power and reduced RMS amplitude of epileptogenic spikes vs PTZ control. Furthermore, our outcomes illustrated that PER dose-dependently attenuated PTZ-evoked anxiety-like behavior, memory deficits, and depressive-like behavior that was validated by a series of behavioral experiments. Moreover PER, significantly reduced lipid peroxidation, AChE, and increased levels of SOD and total thiol in the mice brain via AMPAR antagonism. Post-PTZ kindling provoked overstimulation of BDNF/TrkB signaling and increased release of pro-inflammatory cytokines that were reversed by PER with suppression of iNOS in brain immune cells. In conclusion, our findings highlight that PER might play an auspicious preventive role in the proepileptic transformation of brain circuits via suppression of BDNF/TrkB signaling and reduced transcriptional levels of neuroinflammatory markers leading to improvised epilepsy-induced neurobehavioral and neurochemical effects.
PubMed: 38226351
DOI: 10.1016/j.jsps.2023.101930 -
Frontiers in Immunology 2023Autoimmune encephalitis (AE) is a distinct neuro-immunological disorder associated with the production of autoantibodies against neuronal proteins responsible for...
OBJECTIVE
Autoimmune encephalitis (AE) is a distinct neuro-immunological disorder associated with the production of autoantibodies against neuronal proteins responsible for pharmacoresistant seizures, cognitive decline and behavioral problems. To establish the causal link between leucine-rich glioma inactivated 1 (LGI1) antibody and seizures, we developed an antibody-mediated AE rat model in which serum antibodies (IgG) obtained from blood samples of leucine-rich glioma inactivated 1 (LGI1) protein antibody (IgG) positive encephalitis patients were passively transferred into non-epileptic Wistar rats. Serum IgG of N-methyl-d-aspartate receptor (NMDAR) antibody positive patients were used as positive control since the pathogenicity of this antibody has been previously shown in animal models.
METHODS
Total IgG obtained from the pooled sera of NMDAR and LGI1-IgG positive patients with epileptic seizures and healthy subjects was applied chronically every other day for 11 days into the cerebral lateral ventricle. Spontaneous seizure development was followed by electroencephalography. Behavioral tests for memory and locomotor activity were applied before and after the antibody infusions. Then, pentylenetetrazol (PTZ) was administered intraperitoneally to evaluate seizure susceptibility. Immunohistochemistry processed for assessment of hippocampal astrocyte proliferation and expression intensity of target NMDAR and LGI1 antigens.
RESULTS
No spontaneous activity was observed during the antibody infusions. PTZ-induced seizure stage was significantly higher in the NMDAR-IgG and LGI1-IgG groups compared to control. Besides, memory deficits were observed in the NMDAR and LGI1-IgG groups. We observed enhanced astrocyte proliferation in NMDAR- and LGI1-IgG groups and reduced hippocampal NMDAR expression in NMDAR-IgG group.
SIGNIFICANCE
These findings suggest that neuronal surface auto-antibody administration induces seizure susceptibility and disturbed cognitive performance in the passive transfer rat model of LGI1 AE, which could be a potential model for understanding immune-mediated mechanisms underlying epileptogenesis and highlight the potential targets for immune-mediated seizures in AE patients.
Topics: Humans; Rats; Animals; Leucine; Rats, Wistar; Encephalitis; Seizures; Autoantibodies; Epilepsy; Autoimmune Diseases of the Nervous System; Immunoglobulin G; Glioma; Cognition
PubMed: 38035091
DOI: 10.3389/fimmu.2023.1268986