Project description:We performed gene expression profiling of FACS purified nuclei from hippocampal area CA1 from adult male mice (Calb1xTdtomato mice) subjected to kainic acid-induced status epilepticus (chronic epileptic phase) and control animals.
Project description:Temporal lobe epilepsy (TLE) can develop from alterations in hippocampal structure and circuit characteristics, and can be modeled in mice by administration of kainic acid (KA). Adult neurogenesis in the dentate gyrus (DG) contributes to hippocampal functions and has been reported to contribute to the development of TLE. Some of the phenotypical changes include neural stem and precursor cells (NPSC) apoptosis, shortly after their birth, before they produce hippocampal neurons. Here we explored these early phenotypical changes in the DG 3 days after systemic KA administration to mice. Our specific aim was to understand the molecular mechanisms underlying altered apoptosis levels in NSPC following KA-induced status epilepticus (KA-SE). Accordingly, we chose a multi-omics experimental setup and analyzed DG tissue samples using proteomics, transcriptomics and microRNA profiling techniques. We here present a description of how these date were obtained and provide them to others for further analysis and validation. This may help to further identify and characterize molecular mechanisms involved in the alterations induced shortly after KA-SE in the mouse DG. Total RNA obtained from dentate gyrus 72h after mice were subjected to repeated low dose kainic acid induced status epilepticus or saline i.p. injections
Project description:Temporal lobe epilepsy (TLE) can develop from alterations in hippocampal structure and circuit characteristics, and can be modeled in mice by administration of kainic acid (KA). Adult neurogenesis in the dentate gyrus (DG) contributes to hippocampal functions and has been reported to contribute to the development of TLE. Some of the phenotypical changes include neural stem and precursor cells (NPSC) apoptosis, shortly after their birth, before they produce hippocampal neurons. Here we explored these early phenotypical changes in the DG 3 days after systemic KA administration to mice. Our specific aim was to understand the molecular mechanisms underlying altered apoptosis levels in NSPC following KA-induced status epilepticus (KA-SE). Accordingly, we chose a multi-omics experimental setup and analyzed DG tissue samples using proteomics, transcriptomics and microRNA profiling techniques. We here present a description of how these date were obtained and provide them to others for further analysis and validation. This may help to further identify and characterize molecular mechanisms involved in the alterations induced shortly after KA-SE in the mouse DG. Total RNA obtained from dentate gyrus 72h after mice were subjected to repeated low dose kainic acid induced status epilepticus or saline i.p. injections
Project description:miRNA array comparing the transcription profile of control rats and rats after intra-hippocampal pilocarpine-induced Status Epilepticus (PILO-SE).
Project description:We explored the microRNA expression profile in mice lacking the P2X7 receptor before and after seizures. Genome-wide microRNA profiling was performed using hippocampi from wild-type and P2X7 knock-out mice following status epilepticus induced by intraamygdala kainic acid. This revealed that genetic deletion of the P2X7 receptor results in distinct patterns of microRNA expression. Specifically, we found that in vehicle-injected control mice the lack of P2X7 resulted in the up-regulation of 50 microRNAs and down-regulation of 35 microRNAs. Post-status epilepticus, P2X7 deficiency let to the up-regulation of 44 microRNAs while 13 microRNAs were down-regulated. Moreover, there was only limited overlap between identified P2X7-dependent microRNAs between control conditions and post-status epilepticus, suggesting P2X7 regulating the expression of different microRNAs during normal physiology and pathology. Bioinformatics analysis found that genes targeted via P2X7-dependent microRNAs were particularly overrepresented within pathways involved in intracellular signalling, inflammation and cell death, processes repeatedly linked to P2X7. Moreover, whereas genes involved in signalling pathways and inflammation were common among up-and down-regulated P2X7-dependent miRNAs during physiological and pathological conditions, genes associated with cell death seemed to be restricted to up-regulated miRNAs during both physiological conditions and post-status epilepticus. Taken together, our results demonstrate that P2X7 impacts on the expression profile of microRNAs in the brain, thereby possibly contributing to both the maintenance of normal cellular homeostasis and pathological processes.
Project description:The aim of this work was to identify mRNA expression changes in the ipsilateral hippocampus in the intraamygdala kainic acid (KA) mouse model of status epilepticus. In this model, status epilepticus (prolonged damaging seizures) are triggered by an intraamygdala KA injection. All mice develop epilepsy after a short latency period of 3-5 days. For our experiments, 10-week old mice with a C57BL/6 background were either injected with intraamygdala KA (n = 18) or vehicle (PBS, n = 18). Mice were sacrificed 8 hours following status epilepticus (acute pathology) or 14 days post-status epilepticus (timepoint at which all mice suffer from chronic epilepsy) and ipsilateral hippocampi were quickly dissected and pooled into 3 groups (n = 3 per pooled sample).
Project description:Here, we characterised the effects of experimental status epilepticus on the expression of exosome biosynthesis components and analysed microRNA content in exosome-enriched fractions prepared from the mouse hippocampus. Status epilepticus induced by unilateral intra-amygdala kainic acid resulted in acute subfield-specific, bi-directional changes in transcripts associated with exosome biosynthesis including up-regulation of ESCRT–dependent and –independent pathways. Increased expression of exosome components including Alix were detectable in samples obtained two weeks after status epilepticus and changes occurred in both the ipsilateral and contralateral hippocampus. Small RNAseq analysis of exosome-enriched fractions prepared using two different techniques detected a rich diversity of conserved microRNAs and determined status epilepticus selectively alters microRNA contents, including upregulation of the glia-enriched miR-21a-3p. We also characterized editing sites of the exosome-enriched miRNAs and found six exosome-enriched miRNAs that were Adenosine-to-Inosine (ADAR) edited with the majority of the editing events predicted to occur within miRNA seed regions. However, the prevalence of these editing events was not altered by status epilepticus. These studies demonstrate status epilepticus alters the exosome pathway and its microRNA content, but not editing patterns.
Project description:Status Epilepticus (SE) is an abnormally prolonged seizure that results from either a failure of mechanisms that terminate seizures or from initiating mechanisms that inherently lead to prolonged seizures. Here we report an unbiased analysis of the hippocampal transcriptome of mice with targeted disruption of Dio2 in the astrocytes (Astro-D2KO mouse) undergoing 3 h SE.