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.
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.
Project description:The phosphorylation-based signalling and protein changes occurring in the early phases after a pathophysiological insult, like status epilepticus (SE), have not been detailed. In a companion project, the hippocampi of mice treated with pilocarpine and diazepam were examined by tandem mass tag (TMT11plex) mass spectrometry at 4 and 24 h post-status epilepticus (PXD038241). In the accompanying article, the results implicated posttranscriptional regulatory proteins as early targets of increased phosphorylation. Also, the major targets of decreased phosphorylation at 4 h and 24 h were a subset of post synaptic density scaffold proteins, ion channels and neurotransmitter receptors. Here, the earlier work is repeated on protein and phosphorylation site targets representative of the important SE-dependent changes using parallel reaction monitoring (PRM), supporting the main findings.
Project description:The phosphorylation-based signalling and protein changes occurring in the early phases after a pathophysiological insult, like status epilepticus, have not been detailed. To this end, the hippocampi of mice treated with pilocarpine and diazepam were examined by mass spectrometry at 4 and 24 h post-status epilepticus at vast depth using the tandem mass tag 11-plex system. In the accompanying article, the results implicated posttranscriptional regulatory proteins as early targets of increased phosphorylation. Also, the major targets of decreased phosphorylation at 4 h and 24 h were a subset of post synaptic density scaffold proteins, ion channels and neurotransmitter receptors. Many proteins targeted by dephosphorylation at 4 h also had decreased protein abundance at 24 h, indicating a phosphatase-mediated weakening of synapses.
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:Immunoprecipitation of Upf1-bound RNA from the cytoplasmic and synaptosomal compartments followed by RNA sequencing identified unique populations of NMD-associated transcripts and altered levels after status epilepticus.
Project description:These series contains the controls and the experimental arrays used to map IS5 elements in the E.coli isolates in group A and B. Group A isolates were later named "Motile" isolates, and Group B named "NonMotile. Keywords: parallel sample
Project description:MicroRNAs (miRNAs) are small and endogenously expressed non-coding RNAs that negatively regulate the expression of protein-coding genes at the translational level. Emerging evidence suggests that miRNAs play critical roles in central nervous system under physiological and pathological conditions. However, their expression and functions in status epilepticus (SE) have not been well characterized thus far. Here, we characterized miRNA expression profile in rat hippocampus at 24 hours following SE induced by amygdala stimulation. Hippocampus miRNA profiles of experimental group and control group were generated by deep sequencing, using Hiseq 2000.
Project description:Micorarray analysis was performed on RNA samples from hippocampal cultures infected with either Ad-aCaN or Ad-LacZ or uninfected. Each sample was applied to its own GeneChip (Rat RG-U34A; n=7-9 chips/group). Chips were then processed and scanned using Agilent Affymetrix GeneArray Scanner. MAS5 was used to determine signal intensity and presence/absence calls for the data. Keywords = bioinformatics Keywords = gene expression Keywords = calcineurin Keywords = calcium Keywords = Alzheimer's Keywords = inflamation Keywords = Adenovirus Keywords = astrocytes Keywords = microarray Keywords: parallel sample