Global expression profiling of hippocampus in a mouse model for Mesio-Temporal Lobe Epilepsy
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE88992 | GEO | 2018/06/01
REPOSITORIES: GEO
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Project description:The epilepsies represent one of the most common neurological disorders. Mesial temporal lobe epilepsies (MTLE) are the most frequent form of partial epilepsies and display frequent resistance to anti-epileptic drugs thus representing a major health care problem. In TLE, the origin of seizure activity typically involves the hippocampal formation, which displays major neuropathological features, described with the term hippocampal sclerosis (HS). HS is the most frequent pathological substrate of refractory mesial temporal lobe epilepsy. Complex partial seizures (CPS) are the predominant seizure type associated with medial temporal lobe epilepsy. MTLE is commonly due to mesial temporal sclerosis (MTS). The biology underlying the epilepstic seizures and the transcriptome associated to the seizure in intractable medial temporal lobe epilepsy is ill understood. The aim of the study was to identify potential biomarkers that could identify epileptic seizure. Thus we performed transcriptome profiling of ten medial temporal lobe epilepsy cases which are resistant to the drug and underwent temporal lobectomy. The cases constitutes of patients with intractable complex partial seizure, treated medically and have undergone detailed presurgical evaluation and subjected to surgery for standard temporal lobectomy and amygdalo-hippocampectomy. The spiking areas identified after the electrocorticography will form the test tissues, which compared with the nonspiking areas removed during the surgery, from the same patient. This could probably form one of the appropriate controls, as test and control are from same patient, which eliminates the genome variations that could incur due to the comparison with the tissues from the another patient. Also this could get rid of expression changes due to the treatments undergone by the patient. We performed two color microarray wherein we labled seizure focus (spiking area) with Cy5 and non-seizure region tissues (non-spiking) with Cy3. As a strategy to test the possibility of potential diagnostic biomarkers we are intended to test the differentially regulated molecules in an independent set of epilepsy samples. Two color experiment
2012-12-01 | E-GEOD-25453 | biostudies-arrayexpress
Project description:The epilepsies represent one of the most common neurological disorders. Mesial temporal lobe epilepsies (MTLE) are the most frequent form of partial epilepsies and display frequent resistance to anti-epileptic drugs thus representing a major health care problem. In TLE, the origin of seizure activity typically involves the hippocampal formation, which displays major neuropathological features, described with the term hippocampal sclerosis (HS). HS is the most frequent pathological substrate of refractory mesial temporal lobe epilepsy. Complex partial seizures (CPS) are the predominant seizure type associated with medial temporal lobe epilepsy. MTLE is commonly due to mesial temporal sclerosis (MTS). The biology underlying the epilepstic seizures and the transcriptome associated to the seizure in intractable medial temporal lobe epilepsy is ill understood. The aim of the study was to identify potential biomarkers that could identify epileptic seizure. Thus we performed transcriptome profiling of ten medial temporal lobe epilepsy cases which are resistant to the drug and underwent temporal lobectomy. The cases constitutes of patients with intractable complex partial seizure, treated medically and have undergone detailed presurgical evaluation and subjected to surgery for standard temporal lobectomy and amygdalo-hippocampectomy. The spiking areas identified after the electrocorticography will form the test tissues, which compared with the nonspiking areas removed during the surgery, from the same patient. This could probably form one of the appropriate controls, as test and control are from same patient, which eliminates the genome variations that could incur due to the comparison with the tissues from the another patient. Also this could get rid of expression changes due to the treatments undergone by the patient. We performed two color microarray wherein we labled seizure focus (spiking area) with Cy5 and non-seizure region tissues (non-spiking) with Cy3. As a strategy to test the possibility of potential diagnostic biomarkers we are intended to test the differentially regulated molecules in an independent set of epilepsy samples.
2012-12-01 | GSE25453 | GEO
Project description:Mesial Temporal Lobe Epilepsy (MTLE) is a chronic disease characterized by recurrent unprovoked partial seizures. Current treatments lack long-term efficacy and typically act only to ameliorate the symptomology, rather than to modify the course of the disease. Chronic kainic acid (KA)-induced models of MTLE mimic prominent histopathological and electroencephalographic features of human MTLE, including hippocampal sclerosis, CA1 neuronal loss, astrogliosis, microgliosis, and electrographic hippocampal discharges. Here we examined the transcriptional profiles of the hippocampus of KA - vs sham-injected mice from epileptogenesis to the stabilization of spontaneous recurring seizures. KA (1 nmol) or saline (sham) was injected unilaterally into the dorsal hippocampus of 12 week old C57BL/6J mice, and the ipsilateral (IL) and contralateral (CL) hippocampi were isolated for whole-genome expression profiling (Illumina microarray) or immunohistochemistry 7, 28 and 60 d later. Differential gene expression analysis of the IL hippocampus indicated that 1349, 484, and 439 genes were significantly (fdr<0.05) altered in KA compared to sham at 7, 28 and 60 d, respectively. 108 genes were altered at all time-points assessed, while others were altered in a time-dependent manner, indicative of distinct hippocampal gene expression profiles across the course of disease. Ingenuity Pathway Analysis revealed that specific immune cell and inflammatory signaling pathways were upregulated at 7 and 28 d, in support of a role of neuroinflammation in the disease etiology. The top canonical pathways profile at 60 d was quite distinct from that at 7 and 28 d, although certain inflammatory pathways were still prevalent, indicative of pathways involved in the maintenance of the disease. Consistent with a role of neuroinflammation in MTLE, immunohistochemical analyses demonstrated time-dependent changes in both the intensity of immunoreactivity and number of Iba1- and GFAP-positive cells. To reveal gene networks not apparent with differential expression data alone, weighted gene co-expression analysis (WGCNA) was performed. A gene network that highly associated with 7 d IL-KA (but not 28 and 60 d) was identified, which may point to changes involved in the process of epileptogenesis. Another gene network revealed a group of genes highly associated with changes occurring at 28 and 60 d, but not 7 d, which may point to molecules involved in the generation of spontaneous recurring seizures. Collectively, results indicate that specific pathways, including many associated with neuroinflammation, are activated in a time-dependent manner in MTLE.
2016-09-30 | GSE73878 | GEO
Project description:Mesial temporal lobe epilepsy (MTLE) is the most common medically refractory epilepsy syndrome; kainic acid (KA) induced seizures have been studied as a MTLE model as limbic seizures produced by systemic injections of KA result in a distinctive pattern of neurodegeneration in the hippocampus that resembles human hippocampal sclerosis. In our "2-hit" seizure model, animals subjected to seizures during week 2 of life become more susceptible to seizures later in life and sustain extensive hippocampal neuronal injury after second KA seizures in adulthood. Using high-density oligonucleotide gene arrays, we began to elucidate the molecular basis of this priming effect of early-life seizures and of the age-specific neuroprotection against seizure-induced neuronal injury. We seek to identify target genes for epileptogenesis and cell death by selecting transcripts that are differentially regulated at various times in the P15 and P30 hippocampus. To screen for and identify candidate genes responsible for epileptogenesis and seizure-induced cell death. We hypothesize that active process of cell death signaling and long-term synaptic changes leading to chronic epilepsy is mediated by distinct transcriptional responses in mature brain that are different from those in immature brain. We will select for transcripts that are highly regulated at 1, 6, 24, 72 and 240 hours (h) after KA-induced seizures at P30 compared to P15. These differentially regulated genes will serve as potential target genes for therapeutic intervention. Highly regulated genes identified in our array analysis will then be confirmed by real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Causative roles of select genes will be directly tested by gene silencing using RNA interference technology or by gene delivery using viral vectors.
2008-06-11 | E-GEOD-1834 | biostudies-arrayexpress
Project description:Mesial temporal lobe epilepsy (MTLE) is the most common medically refractory epilepsy syndrome; kainic acid (KA) induced seizures have been studied as a MTLE model as limbic seizures produced by systemic injections of KA result in a distinctive pattern of neurodegeneration in the hippocampus that resembles human hippocampal sclerosis. In our "2-hit" seizure model, animals subjected to seizures during week 2 of life become more susceptible to seizures later in life and sustain extensive hippocampal neuronal injury after second KA seizures in adulthood. Using high-density oligonucleotide gene arrays, we began to elucidate the molecular basis of this priming effect of early-life seizures and of the age-specific neuroprotection against seizure-induced neuronal injury. We seek to identify target genes for epileptogenesis and cell death by selecting transcripts that are differentially regulated at various times in the P15 and P30 hippocampus. To screen for and identify candidate genes responsible for epileptogenesis and seizure-induced cell death. We hypothesize that active process of cell death signaling and long-term synaptic changes leading to chronic epilepsy is mediated by distinct transcriptional responses in mature brain that are different from those in immature brain. We will select for transcripts that are highly regulated at 1, 6, 24, 72 and 240 hours (h) after KA-induced seizures at P30 compared to P15. These differentially regulated genes will serve as potential target genes for therapeutic intervention. Highly regulated genes identified in our array analysis will then be confirmed by real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Causative roles of select genes will be directly tested by gene silencing using RNA interference technology or by gene delivery using viral vectors. Keywords: time-course
2004-10-14 | GSE1834 | GEO
Project description:Most patients with pharmacoresistant mesial temporal lobe epilepsy (MTLE) have hippocampal sclerosis on the postoperative histopathological examination. Although most patients with MTLE do not refer to a family history of the disease, familial forms of MTLE have been reported. We studied surgical specimens from patients with MTLE who had epilepsy surgery for medically intractable seizures. We assessed and compared messenger RNA (mRNA) expression profiles of the tissue lesion found in patients with familial MTLE (n = 3) and sporadic MTLE (n = 5). In addition, we used data from control hippocampi obtained from a public database (n = 7). We obtained expression profiles using the Human Genome U133 Plus 2.0 (Affymetrix) microarray platform. Overall, the molecular profile identified in familial MTLE was distinct from that found in sporadic MTLE. In the tissue of patients with familial MTLE, we found an over-representation of the biological pathways related to protein response, mRNA processing, and synaptic plasticity and function. In sporadic MTLE, the gene expression profile suggests that the inflammatory response is highly activated. We also found enrichment of gene sets involved in inflammatory cytokines and mediators and chemokine receptor pathways in both groups. However, in sporadic MTLE, we also found enrichment of epidermal growth factor signaling, prostaglandin synthesis and regulation, and microglia pathogen phagocytosis pathways. Furthermore, based on the gene expression signatures, we identified different potential compounds to treat patients with familial and sporadic MTLE. To our knowledge, this is the first study assessing the mRNA profile in surgical tissue obtained from patients with familial MTLE and comparing it with sporadic MTLE. Our results clearly show that, despite phenotypic similarities, both forms of MTLE present distinct molecular signatures, thus suggesting different underlying molecular mechanisms that may require distinct therapeutic approaches.
2022-05-09 | GSE202101 | GEO
Project description:Mesial temporal lobe epilepsy (MTLE) is the most common type of focal seizure disorder. In MTLE, seizures typically originate from a sclerotic hippocampus. Approximately one-third of patients do not respond to anti-seizure drugs and have few effective therapeutic options. Surgery to resect or ablate the affected temporal lobe is one such option, but it is not indicated or adequate for all individuals and can have adverse effects. Here, we report the development of an alternative cell therapy strategy for drug-resistant MTLE. The cell therapeutic is derived from a clinical-grade human embryonic stem cell line, and composed of cryopreserved post-mitotic medial ganglionic eminence (MGE)-type GABAergic inhibitory neurons of a predominantly pallial interneuron lineage. Single-dose intrahippocampal delivery of cryopreserved human pallial interneurons in a chronic mouse model of drug-resistant MTLE resulted in consistent and stable suppression of mesiotemporal seizures, with most animals becoming seizure-free. The grafted human interneurons distributed locally, matured, and persisted in the sclerotic hippocampus throughout the 8.5-month study. Pathological hallmarks of MTLE, such as hippocampal granule cell dispersion and sclerosis, were significantly reduced, and epileptic animal survival rates increased, after administration of the human interneurons. Suppression of seizure activity and amelioration of neuropathology were dose-dependent and suggested a broad therapeutic dosing range. No ectopic tissue or teratoma formation was detected after cell transplantation. Furthermore, behavioral abnormalities were not observed at any dose on a battery of assays. These findings support further development of human pallial MGE-type GABAergic interneuron cell therapy for the treatment of drug-resistant focal epilepsies.
2023-10-10 | GSE208672 | GEO
Project description:Hippocampal sclerosis (HS) is the most common neuropathological finding of medically intractable cases of mesial temporal lobe epilepsy (MTLE), the most common form of partial epilepsy. Within the dentate gyrus, HS may be associated with granule cell dispersion and aberrant mossy fiber sprouting, and these pathological changes are accompanied by a range of molecular changes. In this study, we analyzed the gene expression profiles of dentate granule cells of MTLE patients with and without HS to show that next-generation sequencing methods can produce interpretable genomic data from RNA collected from small homogenous cell populations and to shed light on the transcriptional changes associated with HS. 12 samples of dentate granule cells from patients with mesial tempora lobe epilepsy, 5 with hippocampal sclerosis and 7 without hippocampal sclerosis. 10 samples had replicates.
2016-06-29 | E-GEOD-71058 | biostudies-arrayexpress
Project description:Mesial temporal lobe epilepsy (mTLE) is a chronic neurological disease characterized by recurrent seizures. The pathogenic mechanisms underlying TLE involve defects in post-transcriptional regulation of gene expression. So far, transcriptome profiles from epileptic tissue have been performed using whole cells, thereby lacking information on RNA localization and function at a subcellular level. In this project, we set out to understand the compartment-specific total RNA profile of human mTLE tissue samples. For this, we had established a protocol to isolate cytoplasmic and nuclear compartments from human hippocampal tissue. Subcellular RNA was isolated from resected hippocampal (HC) and neo-cortical (Cx) tissue from mTLE no hippocampal sclerosis (non-HS) and mTLE HS International League Against Epilepsy (ILAE) Type 1 or mTLE+HS patients and postmortem control tissue. Later, we used total RNA sequencing (RNA-seq) to profile for the distinct RNA localization in mTLE in comparison to postmortem control tissue and identified disease related pathways in individual cell compartments. Here we report the total RNAseq (coding and non-coding) data.
2022-03-31 | GSE186334 | GEO
Project description:Early childhood convulsions have been correlated with hippocampal neuron loss in patients with intractable temporal lobe epilepsy. Using a "two-hit" rat seizure model, we have shown that animals subjected to kainate (KA)- or hypoxia-induced seizures during early postnatal period showed no cell death, yet sustained more extensive neuronal death after second seizures in adulthood. An early life seizure, without causing overt cellular injury, predisposes the brain to the damaging effect of seizures in later life. Cellular and molecular changes that accompany early seizures and that lead to subsequent epileptogenesis and increased susceptibility to seizure-induced neuronal injury, however, remain poorly understood. We propose to investigate age-specific, time-dependent changes in gene expression that may underlie this priming effect of early-life seizures. We will determine the sequence of gene expression pattern in the hippocampus at various times following KA induced seizures at postnatal day (P) 15. Previous studies have shown that AMPA receptor subtype of glutamate receptors play a crucial role in the age-specific vulnerability and in the long-term epileptogenic effects of perinatal hypoxia seizures. We found that AMPA receptor antagonists block the increased susceptibility caused by early life seizures to later seizures and seizure-induced brain damage. We hypothesize that an alteration of AMPA receptor composition is one of many changes caused by early-life seizures that leads to an increase in Ca2+ permeability, which then results in cascade of downstream events and modifies array of gene expression that promote epileptogenesis and susceptibility to neuronal death in later life. We will examine three time points: 1hr, 72 hr, and 15 days following systemic KA-induced seizures at P15 as we have previously observed structural changes within the hippocampus at these time points. Within an hour of KA seizures, a marked swelling of dendrites, disassembly of dendritic microtubules and glycogen depletion are observed by electron microscopy. Within 5 days, basal dendrites of CA3 hippocampal pyramidal neurons show abnormal spine morphology and decreased branching pattern. 15 days after the seizures, aberrant growth of mossy fibers in the CA3 stratum oriens is observed in animals exposed to KA. Ten hippocampi will be pooled from five animals treated with KA (3mg/kg i.p.) and from five littermate controls injected with PBS. Animals will be decapitated and hippocampi will be rapidly dissected from the brain, flash frozen in liquid nitrogen, and stored at -80C until extraction of total RNA, which will be sent to the center. We will provide 4 tissue samples-2 controls and 2 KA, each a pool of five animals - for each time points. Mixing tissues from multiple rats will normalize single nucleotide polymorphisms and tissue heterogeneity.
2008-06-11 | E-GEOD-1831 | biostudies-arrayexpress