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BioRxiv : the Preprint Server For... Jun 2024ECHS1 Deficiency (ECHS1D) is a rare and devastating pediatric disease that currently has no defined treatments. This disorder results from missense loss-of-function...
ECHS1 Deficiency (ECHS1D) is a rare and devastating pediatric disease that currently has no defined treatments. This disorder results from missense loss-of-function mutations in the gene that result in severe developmental delays, encephalopathy, hypotonia, and early death. ECHS1 enzymatic activity is necessary for the beta-oxidation of fatty acids and the oxidation of branched-chain amino acids within the inner mitochondrial matrix. The pathogenesis of disease remains unknown, however it is hypothesized that disease is driven by an accumulation of toxic metabolites from impaired valine oxidation. To expand our knowledge on disease mechanisms, a novel mouse model of ECHS1D was generated that possesses a disease-associated knock-in (KI) allele and a knock-out (KO) allele. To investigate the behavioral phenotype, a battery of testing was performed at multiple time points, which included assessments of learning, motor function, endurance, sensory responses, and anxiety. Neurological abnormalities were assessed using wireless telemetry EEG recordings, pentylenetetrazol (PTZ) seizure induction, and immunohistochemistry. Metabolic perturbations were measured within the liver, serum, and brain using mass spectrometry and magnetic resonance spectroscopy. To test disease mechanisms, mice were subjected to disease pathway stressors and then survival, body weight gain, and epilepsy were assessed. Mice containing KI/KI or KI/KO alleles were viable with normal development and survival, and the presence of KI and KO alleles resulted in a significant reduction in ECHS1 protein. ECHS1D mice displayed reduced exercise capacity and pain sensation. EEG analysis revealed increased slow wave power that was associated with perturbations in sleep. ECHS1D mice had significantly increased epileptiform EEG discharges, and were sensitive to seizure induction, which resulted in death of 60% of ECHS1D mice. Under basal conditions, brain structure was grossly normal, although histological analysis revealed increased microglial activation in aged ECHS1D mice. Increased dietary valine only affected ECHS1D mice, which significantly exacerbated seizure susceptibility and resulted in death. Lastly, acute inflammatory challenge drove regression and early lethality in ECHS1D mice. In conclusion, we developed a novel model of ECHS1D that may be used to further knowledge on disease mechanisms and to develop therapeutics. Our data suggests altered metabolic signaling and inflammation may contribute to epilepsy in ECHS1D, and these alterations may be attributed to impaired valine metabolism.
PubMed: 38915588
DOI: 10.1101/2024.06.13.598697 -
ACS Omega Jun 2024Pentylenetetrazole (PTZ)-induced kindling is a broadly used experimental model to study the anticonvulsive potential of new and existing chemical moieties with the aim...
Pentylenetetrazole (PTZ)-induced kindling is a broadly used experimental model to study the anticonvulsive potential of new and existing chemical moieties with the aim of discovering drugs hindering seizure progression and associated neurological comorbidities. In the present study, the impact of brivaracetam (BRV) (10 and 20 mg/kg) as monotherapy as well as in combination with 0.25 mg/kg of perampanel (PRP) was investigated on seizure progression with simultaneous electroencephalographic changes in PTZ kindling mouse model. Subsequently, mice were experimentally analyzed for anxiety, cognition, and depression after which their brains were biochemically evaluated for oxidative stress. The outcomes demonstrated that BRV alone delayed the kindling process, but BRV + PRP combination significantly ( < 0.0001) protected the mice from seizures of higher severity and demonstrated an antikindling effect. The PTZ-kindled mice exhibited anxiety, memory impairment, and depression in behavioral tests, which were remarkably less ( < 0.001) in animals treated with drug combination (in a dose-dependent manner) as these mice explored central, illuminated, and exposed zones of open-field test, light/dark box, and elevated plus maze. Moreover, memory impairment was demonstrated by kindled mice, which was significantly ( < 0.001) protected by BRV + PRP as animal's spontaneous alteration, object discrimination, and step-through latencies were increased in various tests employed for the assessment of cognitive abilities. The brains of PTZ-kindled mice had increased malondialdehyde and reduced antioxidant enzymes while treatment with BRV + PRP combination prevented kindling-induced elevation in oxidative markers. The outcomes of this study demonstrate that combining the PRP at low dose augmented the antiseizure properties of BRV as both drugs when administered simultaneously hindered the process of kindling by reducing PTZ-induced excessive electrical activity and oxidative stress in the brain.
PubMed: 38911714
DOI: 10.1021/acsomega.4c00962 -
Neuroscience Letters Jun 2024Brain somatic variants in SLC35A2, an intracellular UDP-galactose transporter, are commonly identified mutations associated with drug-resistant neocortical epilepsy and...
Brain somatic variants in SLC35A2, an intracellular UDP-galactose transporter, are commonly identified mutations associated with drug-resistant neocortical epilepsy and developmental brain malformations, including focal cortical dysplasia type I and mild malformation of cortical development with oligodendroglial hyperplasia in epilepsy (MOGHE). However, the causal effects of altered SLC35A2 function on cortical development remain untested. We hypothesized that focal Slc35a2 knockout (KO) or knockdown (KD) in the developing mouse cortex would disrupt cortical development and change network excitability. Through two independent studies, we used in utero electroporation (IUE) to introduce CRISPR/Cas9/targeted guide RNAs or short-hairpin RNAs into the embryonic mouse brain at day 14.5-15.5 to achieve Slc35a2 KO or KD, respectively, from neural precursor cells. Slc35a2 KO or KD caused disrupted radial migration of electroporated neurons evidenced by heterotopic cells located in lower cortical layers and in the sub-cortical white matter. Slc35a2 KO in neurons did not induce changes in oligodendrocyte number, importantly suggesting that the oligodendroglial hyperplasia observed in MOGHE originates from distinct cell autonomous effects of Slc35a2 mutations. Adult KO mice were implanted with EEG electrodes for 72-hour continuous recording. Spontaneous seizures were not observed in focal Slc35a2 KO mice, but there was reduced seizure threshold following pentylenetetrazol injection. Here we demonstrate that focal Slc35a2 KO or KD in vivo disrupts corticogenesis through altered neuronal migration and that KO leads to reduced seizure threshold. Together these results demonstrate a direct causal role for SLC35A2 in cortical development.
PubMed: 38909838
DOI: 10.1016/j.neulet.2024.137881 -
Scientific Reports Jun 2024Glutamatergic neurotransmission and oxidative stress are involved in the pathophysiology of seizures. Some anticonvulsants exert their effects through modulation of...
Glutamatergic neurotransmission and oxidative stress are involved in the pathophysiology of seizures. Some anticonvulsants exert their effects through modulation of these pathways. Trigonelline (TRG) has been shown to possess various pharmacological effects like neuroprotection. Therefore, this study was performed to determine TRG's anticonvulsant effects, focusing on its potential effects on N-methyl-D-aspartate (NMDA) receptors, a type of glutamate receptor, and oxidative stress state in the prefrontal cortex (PFC) in PTZ-induced seizure in mice. Seventy-two male mice were randomly divided into nine groups. The groups included mice that received normal saline, TRG at doses of 10, 50, and 100 mg/kg, diazepam, NMDA (an agonist), ketamine (an antagonist), the effective dose of TRG with NMDA, as well as sub-effective dose of TRG with ketamine, respectively. All agents were administrated intraperitoneally 60 min before induction of seizures by PTZ. Latency to seizure, total antioxidant capacity (TAC), and malondialdehyde (MDA) levels in serum and PFC were measured. Furthermore, the gene expression of NR2A and NR2B, subunits of NMDA receptors, was measured in the PFC. TRG administration increased the latency to seizure onset and enhanced TAC while reducing MDA levels in both the PFC and serum. TRG also decreased the gene expression of NR2B in the PFC. Unexpectedly, the findings revealed that the concurrent administration of ketamine amplified, whereas NMDA mitigated, the impact of TRG on latency to seizure. Furthermore, NMDA diminished the positive effects of TRG on antioxidant capacity and oxidative stress, while ketamine amplified these beneficial effects, indicating a complex interaction between TRG and NMDA receptor modulation. In the gene expression of NMDA receptors, results showed that ketamine significantly decreased the gene expression of NR2B when co-administrated with a sub-effective dose of TRG. It was found that, at least partially, the anticonvulsant effect of TRG in PTZ-induced seizures in male mice was mediated by the attenuation of glutamatergic neurotransmission as well as the reduction of oxidative stress.
Topics: Animals; Receptors, N-Methyl-D-Aspartate; Oxidative Stress; Anticonvulsants; Mice; Male; Alkaloids; Seizures; Prefrontal Cortex; Malondialdehyde; Ketamine; Pentylenetetrazole; Antioxidants
PubMed: 38902338
DOI: 10.1038/s41598-024-65301-z -
Frontiers in Pharmacology 2024Patients with mutations that alter the function of the sodium channel present with a range of clinical features, including mild to severe seizures, developmental delay,...
Patients with mutations that alter the function of the sodium channel present with a range of clinical features, including mild to severe seizures, developmental delay, intellectual disability, autism, feeding dysfunction, motor impairment, and hypotonia. In an effort to identify compounds that could be potentially beneficial in associated epilepsy, Atkin et al. conducted an screen which resulted in the identification of 90 compounds that effectively reduced sodium influx into the cells expressing the human R1872Q mutation. The top compounds that emerged from this screen included amitriptyline, carvedilol, and nilvadipine. In the current study, we evaluated the ability of these three compounds to increase resistance to 6 Hz or pentylenetetrazole (PTZ)-induced seizures in wild-type CF1 mice and in a mouse line expressing the human R1620L mutation. We also evaluated the effects of fenfluramine administration, which was recently associated with a 60%-90% decrease in seizure frequency in three patients with -associated epilepsy. While amitriptyline, carvedilol, and fenfluramine provided robust protection against induced seizures in CF1 mice, only carvedilol was able to significantly increase resistance to 6 Hz- and PTZ-induced seizures in RL/+ mutants. These results provide support for further evaluation of carvedilol as a potential treatment for patients with mutations.
PubMed: 38895634
DOI: 10.3389/fphar.2024.1397225 -
Molecules (Basel, Switzerland) May 2024Epilepsy is a prevalent neurological disorder characterized by recurrent seizures. Validamycin A (VA) is an antibiotic fungicide that inhibits trehalase activity and is...
Epilepsy is a prevalent neurological disorder characterized by recurrent seizures. Validamycin A (VA) is an antibiotic fungicide that inhibits trehalase activity and is widely used for crop protection in agriculture. In this study, we identified a novel function of VA as a potential anti-seizure medication in a zebrafish epilepsy model. Electroencephalogram (EEG) analysis demonstrated that VA reduced pentylenetetrazol (PTZ)-induced seizures in the brains of larval and adult zebrafish. Moreover, VA reduced PTZ-induced irregular movement in a behavioral assessment of adult zebrafish. The developmental toxicity test showed no observable anatomical alteration when the zebrafish larvae were treated with VA up to 10 µM within the effective range. The median lethal dose of VA in adult zebrafish was > 14,000 mg/kg. These results imply that VA does not demonstrate observable toxicity in zebrafish at concentrations effective for generating anti-seizure activity in the EEG and alleviating abnormal behavior in the PTZ-induced epileptic model. Furthermore, the effectiveness of VA was comparable to that of valproic acid. These results indicate that VA may have a potentially safer anti-seizure profile than valproic acid, thus offering promising prospects for its application in agriculture and medicine.
Topics: Animals; Zebrafish; Anticonvulsants; Disease Models, Animal; Pentylenetetrazole; Epilepsy; Seizures; Electroencephalography; Valproic Acid; Larva; Brain; Inositol
PubMed: 38893448
DOI: 10.3390/molecules29112572 -
NPJ Science of Food Jun 2024Fermenting Chinese medicinal herbs could enhance their bioactivities. We hypothesized probiotic-fermented gastrodia elata Blume (GE) with better potential to alleviate...
Fermenting Chinese medicinal herbs could enhance their bioactivities. We hypothesized probiotic-fermented gastrodia elata Blume (GE) with better potential to alleviate insomnia than that of unfermented, thus the changes in chemical composition and the insomnia-alleviating effects and mechanisms of fermented GE on pentylenetetrazole (PTZ)-induced insomnia zebrafish were explored via high-performance liquid chromatography (HPLC) and mass spectroscopy-coupled HPLC (HPLC-MS), phenotypic, transcriptomic, and metabolomics analysis. The results demonstrated that probiotic fermented GE performed better than unfermented GE in increasing the content of chemical composition, reducing the displacement, average speed, and number of apoptotic cells in zebrafish with insomnia. Metabolomic investigation showed that the anti-insomnia effect was related to regulating the pathways of actin cytoskeleton and neuroactive ligand-receptor interactions. Transcriptomic and reverse transcription qPCR (RT-qPCR) analysis revealed that secondary fermentation liquid (SFL) significantly modulated the expression levels of neurod1, msh2, msh3, recql4, ercc5, rad5lc, and rev3l, which are mainly involved in neuron differentiation and DNA repair. Collectively, as a functional food, fermented GE possessed potential for insomnia alleviation.
PubMed: 38890318
DOI: 10.1038/s41538-024-00277-8 -
Brain, Behavior, and Immunity May 2024The purinergic ATP-gated P2X7 receptor (P2X7R) is increasingly recognized to contribute to pathological neuroinflammation and brain hyperexcitability. P2X7R expression...
BACKGROUND
The purinergic ATP-gated P2X7 receptor (P2X7R) is increasingly recognized to contribute to pathological neuroinflammation and brain hyperexcitability. P2X7R expression has been shown to be increased in the brain, including both microglia and neurons, in experimental models of epilepsy and patients. To date, the cell type-specific downstream effects of P2X7Rs during seizures remain, however, incompletely understood.
METHODS
Effects of P2X7R signaling on seizures and epilepsy were analyzed in induced seizure models using male mice including the kainic acid model of status epilepticus and pentylenetetrazole model and in male and female mice in a genetic model of Dravet syndrome. RNA sequencing was used to analyze P2X7R downstream signaling during seizures. To investigate the cell type-specific role of the P2X7R during seizures and epilepsy, we generated mice lacking exon 2 of the P2rx7 gene in either microglia (P2rx7:Cx3cr1-Cre) or neurons (P2rx7:Thy-1-Cre). To investigate the protective potential of overexpressing P2X7R in GABAergic interneurons, P2X7Rs were overexpressed using adeno-associated virus transduction under the mDlx promoter.
RESULTS
RNA sequencing of hippocampal tissue from wild-type and P2X7R knock-out mice identified both glial and neuronal genes, in particular genes involved in GABAergic signaling, under the control of the P2X7R following seizures. Mice with deleted P2rx7 in microglia displayed less severe acute seizures and developed a milder form of epilepsy, and microglia displayed an anti-inflammatory molecular profile. In contrast, mice lacking P2rx7 in neurons showed a more severe seizure phenotype when compared to epileptic wild-type mice. Analysis of single-cell expression data revealed that human P2RX7 expression is elevated in the hippocampus of patients with temporal lobe epilepsy in excitatory and inhibitory neurons. Functional studies determined that GABAergic interneurons display increased responses to P2X7R activation in experimental epilepsy. Finally, we show that viral transduction of P2X7R in GABAergic interneurons protects against evoked and spontaneous seizures in experimental temporal lobe epilepsy and in mice lacking Scn1a, a model of Dravet syndrome.
CONCLUSIONS
Our results suggest a dual and opposing action of P2X7R in epilepsy and suggest P2X7R overexpression in GABAergic interneurons as a novel therapeutic strategy for acquired and, possibly, genetic forms of epilepsy.
PubMed: 38777288
DOI: 10.1016/j.bbi.2024.05.023 -
Biomedicine & Pharmacotherapy =... Jun 2024Epilepsy is an abiding condition associated with recurrent seizure attacks along with associated neurological and psychological emanation owing to disparity of...
Ameliorative effect of Nyctanthes arbor-tristis L. by suppression of pentylenetetrazole-induced kindling in mice: An insight from EEG, neurobehavioral and in-silico studies.
Epilepsy is an abiding condition associated with recurrent seizure attacks along with associated neurological and psychological emanation owing to disparity of excitatory and inhibitory neurotransmission. The current study encompasses the assessment of the Nyctanthes arbor-tristis L. methanolic extract (Na.Cr) in the management of convulsive state and concomitant conditions owing to epilepsy. The latency of seizure incidence was assessed using pentylenetetrazol (PTZ) kindling models along with EEG in Na.Cr pretreated mice, trailed by behavior assessment (anxiety and memory), biochemical assay, histopathological alterations, chemical profiling through GCMS, and molecular docking. The chronic assessment of PTZ-induced kindled mice depicted salvation in a dose-related pattern and outcomes were noticeable with extract at 400 mg/kg. The extract at 400 mg/kg defends the progress of kindling seizures and associated EEG. Co-morbid conditions in mice emanating owing to epileptic outbreaks were validated by behavioral testing and the outcome depicted a noticeable defense related to anxiety (P<0.001) and cognitive deficit (P<0.001) at 400 mg/kg. The isolated brains were evaluated for oxidative stress and the outcome demonstrated a noticeable effect in a dose-dependent pattern. Treatment with Na.Cr. also preserved the brain from PTZ induced neuronal damage as indicated by histopathological analysis. Furthermore, the GCMS outcome predicted 28 compounds abundantly found in the plant. The results congregated in the current experiments deliver valued evidence about the defensive response apportioned by Na.Cr which might be due to decline in oxidative stress, AChE level, and GABAergic modulation. These activities may contribute to fundamental pharmacology and elucidate some mechanisms behind the activities of Nyctanthes arbor-tristis.
Topics: Animals; Pentylenetetrazole; Kindling, Neurologic; Mice; Plant Extracts; Male; Seizures; Electroencephalography; Anticonvulsants; Behavior, Animal; Molecular Docking Simulation; Computer Simulation; Disease Models, Animal; Oxidative Stress; Epilepsy
PubMed: 38776672
DOI: 10.1016/j.biopha.2024.116791 -
International Immunopharmacology Jun 2024Epilepsy is a chronic disabling disease poorly controlled by available antiseizure medications. Oridonin, a bioactive alkaloid with anti-inflammatory properties and...
BACKGROUND
Epilepsy is a chronic disabling disease poorly controlled by available antiseizure medications. Oridonin, a bioactive alkaloid with anti-inflammatory properties and neuroprotective effects, can inhibit the increased excitability of neurons caused by glutamate accumulation at the cellular level. However, whether oridonin affects neuronal excitability and whether it has antiepileptic potential has not been reported in animal models or clinical studies.
METHOD
Pentylenetetrazol was injected into mice to create a model of chronic epilepsy. Seizure severity was assessed using the Racine scale, and the duration and latency of seizures were observed. Abnormal neuronal discharge was detected using electroencephalography, and neuronal excitability was assessed using calcium imaging. Damage to hippocampal neurons was evaluated using Hematoxylin-Eosin and Nissl staining. The expression of the NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome and other pyroptosis-related proteins was determined using western blotting and immunofluorescence. A neuronal pyroptosis model was established using the supernatant of BV2 cells treated with lipopolysaccharide and adenosine triphosphate to stimulate hippocampal neurons.
RESULTS
Oridonin (1 and 5 mg/kg) reduced neuronal damage, increased the latency of seizures, and shortened the duration of fully kindled seizures in chronic epilepsy model mice. Oridonin decreased abnormal discharge during epileptic episodes and suppressed increased neuronal excitability. In vitro experiments showed that oridonin alleviated pyroptosis in hippocampal HT22 neurons.
CONCLUSION
Oridonin exerts neuroprotective effects by inhibiting pyroptosis through the NLRP3/caspase-1 pathway in chronic epilepsy model mice. It also reduces pyroptosis in hippocampal neurons in vitro, suggesting its potential as a therapy for epilepsy.
Topics: Animals; Diterpenes, Kaurane; NLR Family, Pyrin Domain-Containing 3 Protein; Neuroprotective Agents; Epilepsy; Pyroptosis; Mice; Anticonvulsants; Male; Hippocampus; Neurons; Disease Models, Animal; Pentylenetetrazole; Mice, Inbred C57BL; Inflammasomes; Cell Line; Seizures
PubMed: 38759374
DOI: 10.1016/j.intimp.2024.112247