Project description:Using microarray analyses and subsequent verification by RT-PCR, we studied the changes in gene expression in the inferior colliculus after an ictal event in one models of audiogenic epilepsy, genetic audiogenic seizure hamster (GASH:Sal). GASH:Sal, a hamster strain developed at the University of Salamanca, exhibits genetic audiogenic epilepsy similar to human Grand Mal epilepsy. GASH:Sal shows an autosomal recessive inheritance for susceptibility to audiogenic seizures, which manifest more severely in young animals; the seizure severity progressively declines with age. Genetic animal models of epilepsy are an important tool for further understanding the basic cellular mechanisms underlying epileptogenesis and for developing novel antiepileptic drugs. We conducted a comparative study of gene expression in the inferior colliculus, a nucleus that triggers audiogenic seizures, using two animal models, the Wistar audiogenic rat (WAR) and the genetic audiogenic seizure hamster (GASH:Sal). For this purpose, both models were subjected to auditory stimulation, and 60 minutes after stimulation, the inferior colliculi were collected. As a control, intact Wistar rats and Syrian hamsters were subjected to identical stimulation and tissue preparation protocols to those performed on the experimental animals.
Project description:Using microarray analyses and subsequent verification by RT-PCR, we studied the changes in gene expression in the inferior colliculus after an ictal event in one models of audiogenic epilepsy, genetic audiogenic seizure hamster (GASH:Sal). GASH:Sal, a hamster strain developed at the University of Salamanca, exhibits genetic audiogenic epilepsy similar to human Grand Mal epilepsy. GASH:Sal shows an autosomal recessive inheritance for susceptibility to audiogenic seizures, which manifest more severely in young animals; the seizure severity progressively declines with age. Genetic animal models of epilepsy are an important tool for further understanding the basic cellular mechanisms underlying epileptogenesis and for developing novel antiepileptic drugs. We conducted a comparative study of gene expression in the inferior colliculus, a nucleus that triggers audiogenic seizures, using two animal models, the Wistar audiogenic rat (WAR) and the genetic audiogenic seizure hamster (GASH:Sal). For this purpose, both models were subjected to auditory stimulation, and 60 minutes after stimulation, the inferior colliculi were collected. As a control, intact Wistar rats and Syrian hamsters were subjected to identical stimulation and tissue preparation protocols to those performed on the experimental animals. A total of 24 animals were used in this study according to the following distribution: 12 control Syrian hamsters (Mesocricetus auratus) and 12 GASH:Sal at 16 weeks of age and a body weight of approximately 60 g. Six animals Syrian and GASH:Sal hamsters, respectively, were exposed to auditory stimulation, and 60 min after the seizures, we harvested the IC for all gene expression analyses (stimulated Syrian hamsters and stimulated GASH:Sal hamsters). As controls, other six animals Syrian and GASH:Sal hamsters, respectively, were not exposed to the same stimulation (Syrian hamsters and GASH:Sal hamsters).
Project description:Using microarray analyses and subsequent verification by RT-PCR, we studied the changes in gene expression in the inferior colliculus after an ictal event in one models of audiogenic epilepsy, Wistar audigenic rat (WAR). WAR is a genetically selected strain susceptible to audiogenic seizures that was inbred in the School of Medicine of Ribeirão Preto (Brazil) beginning in 1990. This strain is a model of audiogenic idiopathic epilepsy that develops tonic-clonic generalized seizures. Genetic animal models of epilepsy are an important tool for further understanding the basic cellular mechanisms underlying epileptogenesis and for developing novel antiepileptic drugs. We conducted a comparative study of gene expression in the inferior colliculus, a nucleus that triggers audiogenic seizures, using two animal models, the Wistar audiogenic rat (WAR) and the genetic audiogenic seizure hamster (GASH:Sal). For this purpose, both models were subjected to auditory stimulation, and 60 minutes after stimulation, the inferior colliculi were collected. As a control, intact Wistar rats and Syrian hamsters were subjected to identical stimulation and tissue preparation protocols to those performed on the experimental animals.
Project description:The GASH/Sal hamster (Genetic audiogenic seizure, Salamanca) is a model of audiogenic seizures with the epileptogenic focus localized in the inferior colliculus (IC). The sound-induced seizures exhibit a short latency (7-9 seconds), which implies innate protein disturbances in the IC as a basis for seizure susceptibility and generation. Here, we aim to study the protein profile in the GASH/Sal IC in comparison to controls. Protein samples from the IC were processed for enzymatic digestion and then analyzed by mass spectrometry in Data-Independent Acquisition mode. After identifying the proteins using the UniProt database, we selected those with differential expression. We identified 5254 proteins, of which 184 were differentially expressed, 126 upregulated and 58 downregulated. Moreover, a small number of proteins were uniquely found in the GASH/Sal or the control. The resuls indicated a protein profile alteration in the epileptogenic nucleus that might underlie the innate occuring audiogenic seizures in the GASH/Sal model.
Project description:Using microarray analyses and subsequent verification by RT-PCR, we studied the changes in gene expression in the inferior colliculus after an ictal event in one models of audiogenic epilepsy, Wistar audigenic rat (WAR). WAR is a genetically selected strain susceptible to audiogenic seizures that was inbred in the School of Medicine of Ribeirão Preto (Brazil) beginning in 1990. This strain is a model of audiogenic idiopathic epilepsy that develops tonic-clonic generalized seizures. Genetic animal models of epilepsy are an important tool for further understanding the basic cellular mechanisms underlying epileptogenesis and for developing novel antiepileptic drugs. We conducted a comparative study of gene expression in the inferior colliculus, a nucleus that triggers audiogenic seizures, using two animal models, the Wistar audiogenic rat (WAR) and the genetic audiogenic seizure hamster (GASH:Sal). For this purpose, both models were subjected to auditory stimulation, and 60 minutes after stimulation, the inferior colliculi were collected. As a control, intact Wistar rats and Syrian hamsters were subjected to identical stimulation and tissue preparation protocols to those performed on the experimental animals. A total of 15 animals were used in this study according to the following distribution: 9 male WAR and 6 male control rats (Rattus norvegicus, Wistar albino, Charles River Laboratories) at 12 weeks of age and a body weight of approximately 230 g. The animals were exposed to auditory stimulation, and 60 min after the seizures, we harvested the IC for all gene expression analyses. As controls, normal Wistar rats were exposed to the same stimulation according to the identical procedure. For gene microarray (Rat Gene 1.0 ST), the rats were randomly divided into two groups, and we used both sides of the IC (ipsilateral and contralateral) from each animal: stimulated Wistar rats and stimulated WAR rats.
Project description:Absence epilepsy syndromes are part of the genetic generalized epilepsies, the pathogenesis of which remains poorly understood, although a polygenic architecture is presumed. Current focus on single molecule or gene identification to elucidate epileptogenic drivers is unable to fully cap-ture the complex dysfunctional interactions occurring at a genetic/proteomic/metabolomic level. Here, we employ a multi-omic, network-based approach to characterize the molecular signature associated with absence epilepsy-like phenotype seen in a well validated rat model of genetic generalized epilepsy with absence seizures. Electroencephalographic and behavioral data was collected from Genetic Absence Epilepsy Rats from Strasbourg (GAERS, n=6) and non-epileptic controls (NEC, n=6), followed by proteomic and metabolomic profiling of the cortical and tha-lamic tissue of rats from both groups. The general framework of weighted correlation network analysis was used to identify groups of highly correlated proteins and metabolites, which were then functionally annotated through joint pathway enrichment analysis. In both brain regions a large protein-metabolite module was found to be highly associated with the GAERS strain, ab-sence seizures and associated anxiety and depressive-like phenotype. Quantitative pathway analysis indicated enrichment in oxidative pathways and a downregulation of the lysine degra-dation pathway in both brain regions. GSTM1 and ALDH2 were identified as central regulatory hubs of the seizure-associated module in the somatosensory cortex and thalamus, respectively. These enzymes are involved in lysine degradation and play important roles in maintaining oxi-dative balance. We conclude that the dysregulated pathways identified in the seizure-associated module may be involved in the aetiology and maintenance of absence seizure activity. This dysregulated activity could potentially be modulated by targeting one or both central regulatory hubs.
Project description:This study was performed to test the hypothesis that systemic leukocyte gene expression has prognostic value differentiating low from high seizure frequency refractory temporal lobe epilepsy (TLE). A consecutive series of sixteen patients with refractory temporal lobe epilepsy was studied. Based on a median baseline seizure frequency of 2.0 seizures per month, low versus high seizure frequency was defined as < 2 seizures/month and > 2 seizures/month, respectively.
Project description:Epilepsy is a heterogenous group of disorders defined by recurrent seizure activity due to abnormal synchronized activity of neurons. A growing number of epilepsy cases are believed to be caused by genetic factors and copy number variants (CNV) contribute to up to 5% of epilepsy cases. However, CNVs in epilepsy are usually large deletions or duplications involving multiple neurodevelopmental genes. Here we identify focal amplifications of regulatory regions of receptor tyrosine kinase genes as a genetic abnormality in epileptogenic brains. Whole genome DNA methylation profiling identified three main clusters of which one showed strong association with receptor tyrosine kinase genes. By copy number analysis, we identified focal copy number gains involving EGFR and PDGFRA in brain tissue of patients who underwent seizure focus resection for treatment-resistant epilepsy. The dysplastic neurons showed marked overexpression of pEGFR and pPDGFRA, while glial and endothelial cells were negative. Sequencing and DNA methylation analysis revealed that enhancer regions of EGFR and PDGFRA gene promoter were amplified, while coding regions did not show copy number abnormalities or somatic mutations. Our results identify somatic focal copy number gains of noncoding regulatory regions in the brain as a previously unrecognized genetic driver in epilepsy. Somatic copy number aberrations of regulatory regions represent a mechanism of abnormal activation of receptor tyrosine kinase genes in epilepsy. Upregulated receptor tyrosine kinases provide a potential avenue for therapy in seizure disorders.
Project description:Epilepsy is characterized by hypersynchronous neuronal discharges, which are associated with an increased cerebral metabolic rate of oxygen and ATP demand. Uncontrolled seizure activity (status epilepticus) results in mitochondrial exhaustion and ATP depletion, which potentially generate energy mismatch and neuronal loss. Many cells can adapt to increased energy demand by increasing metabolic capacities. However, acute metabolic adaptation during epileptic activity and its relationship to chronic epilepsy remains poorly understood. We elicited seizure-like events (SLEs) in an in vitro model of status epilepticus for eight hours. Electrophysiological recording and tissue oxygen partial pressure recordings were performed. After eight hours of ongoing SLEs, we used proteomics-based kinetic modeling to evaluate changes in metabolic capacities. We compared our findings regarding acute metabolic adaptation to published proteomic and transcriptomic data from chronic epilepsy patients. Epileptic tissue acutely responded to uninterrupted SLEs by upregulating ATP production capacity. This was achieved by a coordinated increase in the abundance of proteins from the respiratory chain and oxidative phosphorylation system. In contrast, chronic epileptic tissue shows a 25-40% decrease in ATP production capacity. In summary, our study reveals that epilepsy leads to dynamic metabolic changes. Acute epileptic activity boosts ATP production, while chronic epilepsy reduces it significantly.