Next Generation Sequencing (NGS) of miRNAs in rat hippocampal tissues
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ABSTRACT:
ORGANISM(S): Rattus norvegicus
PROVIDER: GSE124332 | GEO | 2020/03/31
REPOSITORIES: GEO
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Project description:Purpose: to evaluate changes in the transcriptome of hippocampal cells during the course of epileptogenesis, from the early events post status epilepticus (SE) to the onset of recurrent spontaneous seizures. Experimental Design: Gene expression profiling was analyzed in hippocampi of rats subjected to the pilocarpine model of epilepsy at different times during the course of epileptogenesis: 3 days post-SE (3D), 7 days post-SE (7D), and immediately (up to 12h) after the first spontaneous seizure (Chronic). All three pilocarpine subgroups had a corresponding age-matched control group (saline-treated rats), from which normal hippocampi samples were obtained at the same experimental time points. Independent microarray hybridizations were carried out for each sample (n = 5, per experimental group) with oligonucleotide microarrays covering 34,000 transcripts representing most of the known and predictive genes of the rat genome (CodeLink⢠Rat Whole Genome Bioarrays, GE Healthcare), following the manufacturerâs protocol. Results: differential expression of almost 1,400 genes was detected during the course of epileptogenesis, from the early events post status epilepticus (SE) to the onset of recurrent spontaneous seizures. Most of these genes are novel and displayed an up-regulation after SE. Noteworthy, a group of 128 genes functioning in neurogenesis, apoptosis, immune response, and intracellular signal transduction was found consistently hyper-expressed throughout epileptogenesis, indicating stable molecular alterations within the hippocampus. Those include modulation of the MAPK, Jak-STAT, PI3K, TGF-beta, and mTOR signaling pathways. Differential expression of genes from the p38 MAPK pathway, mediating inflammation and neurogenesis, was also confirmed by real-time PCR. These findings reveal dynamic molecular changes occurring in the hippocampus that may serve as a starting point for the generation of new hypothesis regarding the underlying mechanisms of epilepsy and for the designing of alternative therapeutic strategies. Keywords: gene expression changes during epileptogenesis. We performed a genome wide analysis of genes differentially expressed during epileptogenesis. Virtually, all possible changes in the rat transcriptome were monitored at distinct time points corresponding to the latent to chronic phase transition of the pilocarpine model of epilepsy, which is probably the most extensively studied chemically inductive model of TLE. Genes identified as being differentially expressed were classified based on their respective biological functions to envisage processes and pathways likely implicated in epileptogenesis, as well as their possible value as targets for therapy. Results were expressed as fold variation, and genes displaying greater than 2-fold changes in transcript abundance and p<0.01 were selected.
2010-02-09 | E-GEOD-14763 | biostudies-arrayexpress
Project description:Purpose: to evaluate changes in the transcriptome of hippocampal cells during the course of epileptogenesis, from the early events post status epilepticus (SE) to the onset of recurrent spontaneous seizures. Experimental Design: Gene expression profiling was analyzed in hippocampi of rats subjected to the pilocarpine model of epilepsy at different times during the course of epileptogenesis: 3 days post-SE (3D), 7 days post-SE (7D), and immediately (up to 12h) after the first spontaneous seizure (Chronic). All three pilocarpine subgroups had a corresponding age-matched control group (saline-treated rats), from which normal hippocampi samples were obtained at the same experimental time points. Independent microarray hybridizations were carried out for each sample (n = 5, per experimental group) with oligonucleotide microarrays covering 34,000 transcripts representing most of the known and predictive genes of the rat genome (CodeLink™ Rat Whole Genome Bioarrays, GE Healthcare), following the manufacturer’s protocol. Results: differential expression of almost 1,400 genes was detected during the course of epileptogenesis, from the early events post status epilepticus (SE) to the onset of recurrent spontaneous seizures. Most of these genes are novel and displayed an up-regulation after SE. Noteworthy, a group of 128 genes functioning in neurogenesis, apoptosis, immune response, and intracellular signal transduction was found consistently hyper-expressed throughout epileptogenesis, indicating stable molecular alterations within the hippocampus. Those include modulation of the MAPK, Jak-STAT, PI3K, TGF-beta, and mTOR signaling pathways. Differential expression of genes from the p38 MAPK pathway, mediating inflammation and neurogenesis, was also confirmed by real-time PCR. These findings reveal dynamic molecular changes occurring in the hippocampus that may serve as a starting point for the generation of new hypothesis regarding the underlying mechanisms of epilepsy and for the designing of alternative therapeutic strategies. Keywords: gene expression changes during epileptogenesis.
2010-02-09 | GSE14763 | GEO
Project description:Global expression profiling of epileptogenesis has been confounded by variability across laboratories, epilepsy models, tissue sampled and experimental platforms, with the result that very few genes demonstrate consistent expression changes. The present study minimizes these confounds by combining Affymetrix microarray datasets from seven laboratories, using three status epilepticus (SE) models of epilepsy in rats (pilocarpine, kainate, self-sustained SE or SSSE) and the rat kindling model. Total RNA was harvested from laser-captured dentate granule cells from 6 rats at three times during the early-to-mid latent phase that precedes epilepsy symptoms in the SE models (1, 3 and 10 days after SE), or 24 hr after the first stage 2, stage 4 and stage 5 seizure in the kindling model. Each epilepsy model was studied in two independent laboratories except SSSE. The initial goals of this study were to a) identify model-independent transcriptional changes in dentate granule cells that could point to novel intervention targets for epileptogenesis, b) characterize the basal transcriptional profile of dentate granule cells, and c) identify genes that have highly variable expression.
2013-06-08 | GSE47752 | GEO
Project description:Global expression profiling of epileptogenesis has been confounded by variability across laboratories, epilepsy models, tissue sampled and experimental platforms, with the result that very few genes demonstrate consistent expression changes. The present study minimizes these confounds by combining Affymetrix microarray datasets from seven laboratories, using three status epilepticus (SE) models of epilepsy in rats (pilocarpine, kainate, self-sustained SE or SSSE) and the rat kindling model. Total RNA was harvested from laser-captured dentate granule cells from 6 rats at three times during the early-to-mid latent phase that precedes epilepsy symptoms in the SE models (1, 3 and 10 days after SE), or 24 hr after the first stage 2, stage 4 and stage 5 seizure in the kindling model. Each epilepsy model was studied in two independent laboratories except SSSE. The initial goals of this study were to a) identify model-independent transcriptional changes in dentate granule cells that could point to novel intervention targets for epileptogenesis, b) characterize the basal transcriptional profile of dentate granule cells, and c) identify genes that have highly variable expression. Each experimental group consists of 6 rats (biological replicates) from one laboratory at a single time point, except for the SSSE group (6 at day 1 after SSSE, 5 controls and at day 3 after SSSE, 4 at day 10). Thus granule cells were harvested from 164 rats.
2013-06-08 | E-GEOD-47752 | biostudies-arrayexpress
Project description:Transient brain insults including status epilepticus (SE) can initiate a process termed ‘epileptogenesis’ that results in chronic temporal lobe epilepsy (TLE). As a consequence, the entire tri-synaptic circuit of the hippocampus is fundamentally impaired. A key role in epileptogenesis has been attributed to the CA1 region as the last relay station in the hippocampal circuit and as site of aberrant plasticity, e.g. mediated by acquired channelopathies. The transcriptional profiles of the distinct hippocampal neurons are highly dynamic during epileptogenesis. Here, we aimed to elucidate the early SE-elicited mRNA signature changes and the respective upstream regulatory cascades in CA1. RNA sequencing of CA1 was performed in the mouse pilocarpine-induced SE model at multiple time points ranging from 6 to 72 hours after the initial insult. Bioinformatics was used to decipher altered gene expression, signalling cascades and their corresponding cell type profiles. Robust transcriptomic changes were detected at 6h after SE and at subsequent time points during early epileptogenesis. Major differentially expressed mRNAs encoded primarily immediate early and excitability-related gene products, as well as genes encoding immune signalling factors.
2023-12-20 | GSE241219 | GEO
Project description:LEV is known to be involved in neuroprotection via anti-angiogenesis and anti-inflammatory activities against blood-brain barrier dysfunction in the acute phase of epileptogenesis after SE, but the mechanism remains unclear. The purpose of this study is to comprehensively examine the gene expression in hippocampus of LEV-treated and untreated pilocarpine induced (PILO-) SE mouse in order to understand the whole process of early epileptogenesis.
2022-06-09 | GSE205373 | GEO
Project description:Anti-epileptogenic agents that prevent the development of epilepsy following a brain insult remain the holy grail of epilepsy therapeutics. In order to identify such drugs, it is necessary to first understand the cellular and molecular events that underlie the epileptogenic process, from initial insult to the onset of spontaneous recurrent seizures. We have employed a label-free proteomic approach that allows quantification of large numbers of brain-expressed proteins in a single analysis in the well-established kainate (KA) mouse (C57BL/6J) model of epileptogenesis. In addition, we have incorporated two putative antiepileptogenic drugs, PSD95BP and 1400W, to give an insight into how such agents might ameliorate the epileptogenesis. The test drugs were administered at appropriate time-points after induction of status epilepticus (SE) and animals were euthanized at 7 days, their hippocampi removed, and subjected to LC-MS/MS analysis. A total of 2,579 proteins were identified; their normalized abundance was compared between treatment groups using ANOVA, with correction for multiple testing by false discovery rate. Significantly altered proteins were subjected to gene ontology analysis to look for enrichment of specific biological processes. KA-induced SE was most robustly associated with an increase in proteins involved in neuroinflammation, oxidative stress, cell-cell interactions and synaptic plasticity. Treatment with PSD95BP (Tat-NR2B9c) or an iNOS inhibitor, 1400W modulated several of these proteins. Our observations require validation in a larger-scale investigation, with candidate proteins explored in more detail. Nevertheless, this study has identified several mechanisms by which epilepsy might be developed and several targets for novel drug development.
2019-05-23 | PXD010986 | Pride
Project description:The molecular mechanism underlying the role of hippocampal hilar interneuron degeneration in temporal lobe epilepsy (TLE) remains unclear. Especially, very few studies have focused on the role of neuronal nitric oxide synthase (nNOS, encoded by Nos1) containing hilar interneurons in TLE. In the present study, Nos1 conditional knockout mice were constructed, and we found that selective deletion of Nos1 in hilar interneurons rather than dentate granular cells (DGCs) triggered epileptogenesis. The level of nNOS was downregulated in patients and mice with TLE. Nos1 deletion led to excessive epilepsy-like excitatory input circuit formation and hyperexcitation of DGCs. Replenishment of hilar nNOS protein blocked epileptogenic development and memory impairment in pilocarpine-induced TLE mice. Moreover, chronic treatment with DETA/NONOate, a slowly released exogenous nitric oxide (NO) donor, prevented aberrant neural circuits of DGCs and the consequent epileptogenesis without acute antiseizure effects. Therefore, we concluded that NO donor therapy may be a novel anti-epileptogenesis strategy, different from existing antiseizure medications (ASMs), for curing TLE.
2024-10-21 | GSE274303 | GEO
Project description:Analysis of the dentate gyrus of amygdala electrical stimulation model of temporal lobe epilepsy. Results provide insight into the molecular mechanism underlying epileptogenesis. This study was designed to estimate changes in miRNA expression levels after 7, 14, 30 and 90 days after electrical stimulation of amygdala as a model of temporal lobe epilepsy. The advantage of this study is time matched control (sham operated animals sacrificed at the same age as stimulated animals).
2013-08-14 | E-GEOD-49850 | biostudies-arrayexpress
Project description:miRNA array comparing the transcription profile of control rats and rats after intra-hippocampal pilocarpine-induced Status Epilepticus (PILO-SE).
2016-04-28 | E-MTAB-4633 | biostudies-arrayexpress