Project description:Maladaptive upregulation of aminoprocalcitonin fuels seizure self-sustaining by boosting energy supply in refractory status epilepticus
Project description:miRNA array comparing the transcription profile of control rats and rats after intra-hippocampal pilocarpine-induced Status Epilepticus (PILO-SE).
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: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:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
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: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: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.