Project description:Febrile seizures are the most prevalent type of seizures among children up to 5 years of age (2-4% of Western-European children). Complex febrile seizures are associated with an increased risk to develop temporal lobe epilepsy. To investigate short- and long-term effects of experimental febrile seizures (eFS), we induced eFS in highly febrile convulsion-susceptible C57BL/6J mice at post-natal day 10 by exposure to hyperthermia (HT) and compared them to normotherm-exposed (NT) mice. We detected structural re-organization in the hippocampus 14 days after eFS. To identify molecular candidates, which entrain this structural re-organization, we investigated temporal changes in mRNA expression profiles eFS 1 hour to 56 days after eFS. We identified 931 regulated genes and profiled several candidates using in situ hybridization and histology at 3 and 14 days after eFS. This is the first study to report genome-wide transcriptome analysis after eFS in mice. We identify temporal regulation of multiple processes, such as stress-, immune- and inflammatory responses, glia activation, glutamate-glutamine cycle and myelination. Identification of the short- and long-term changes after eFS is important to elucidate the mechanisms contributing to epileptogenesis. Acute, short-, and long-term effects of prolonged febrile seizures on gene expression were investigated in whole hippocampal samples. Samples were taken from C57BL/6J animals one hour (HT n = 8, NT n = 8), three days (HT n = 6, NT n = 6), fourteen days (HT n = 6, NT n = 6), and fifty-six days (HT n = 6, NT n = 6) after HT. Two-channel oligonucleotide microarray analysis was performed with an NT and HT sample on the same chip, including a dye-swap (technical replicate). 3 failed hybridizations were omitted from further analysis.
Project description:Febrile seizures are the most prevalent type of seizures among children up to 5 years of age (2-4% of Western-European children). Complex febrile seizures are associated with an increased risk to develop temporal lobe epilepsy. To investigate short- and long-term effects of experimental febrile seizures (eFS), we induced eFS in highly febrile convulsion-susceptible C57BL/6J mice at post-natal day 10 by exposure to hyperthermia (HT) and compared them to normotherm-exposed (NT) mice. We detected structural re-organization in the hippocampus 14 days after eFS. To identify molecular candidates, which entrain this structural re-organization, we investigated temporal changes in mRNA expression profiles eFS 1 hour to 56 days after eFS. We identified 931 regulated genes and profiled several candidates using in situ hybridization and histology at 3 and 14 days after eFS. This is the first study to report genome-wide transcriptome analysis after eFS in mice. We identify temporal regulation of multiple processes, such as stress-, immune- and inflammatory responses, glia activation, glutamate-glutamine cycle and myelination. Identification of the short- and long-term changes after eFS is important to elucidate the mechanisms contributing to epileptogenesis.
Project description:We analyzed the transcriptomic profile of CA3 explants surgically obtained from patients with refractory MTLE (mesial temporal lobe epilepsy) and HS (hippocampal sclerosis) in order to investigate if the initial precipitating injury (IPI) influences the molecular mechanisms underlying this condition. CA3 transcriptomic profile was found to be significantly different in cases with prolonged febrile seizures as the IPI (identified here as FS) when compared to correspondent data from cases without febrile seizure history (NFS). CA3 transcriptomic profiles of FS and NFS were compared in order to identify differentially expressed transcripts
Project description:We analyzed the transcriptomic profile of CA3 explants surgically obtained from patients with refractory MTLE (mesial temporal lobe epilepsy) and HS (hippocampal sclerosis) in order to investigate if the initial precipitating injury (IPI) influences the molecular mechanisms underlying this condition. CA3 transcriptomic profile was found to be significantly different in cases with prolonged febrile seizures as the IPI (identified here as FS) when compared to correspondent data from cases without febrile seizure history (NFS).
Project description:Prolonged febrile seizures history (FH) in early childhood is associated with refractory temporal lobe epilepsy (RTLE). FH-RTLE patients may have early (E, before 4 YOA) or late (L, mid-adolescence, early adult life) disease onset. In order to investigate molecular mechanisms underlying E and L forms we compared differentially expressed (DE) and complete (CO) transcriptional networks from hippocampal CA3 explants obtained from E and L patients.
Project description:Adult neurogenesis continuously contributes new neurons to hippocampal circuits and the programmed death of a subset of immature cells provides a primary mechanism controlling this contribution. Epileptic seizures induce strong structural changes in the hippocampus, including the induction of adult neurogenesis, changes in gene expression and mitochondrial dysfunction, which may all contribute to epileptogenesis. However, a possible interplay between this factors remains largely unexplored. Here, we investigated gene expression changes in the hippocampal dentate gyrus shortly after prolonged seizures induced by kainic acid, focusing on mitochondrial functions. Using comparative proteomics, we identified networks of proteins differentially expressed shortly after seizure induction, including members of the BCL2 family and other mitochondrial proteins. Within these networks, we report for the first time that the atypical BCL2 protein BCL2L13 controls caspase-3 activity and cytochrome C release in neural stem/progenitor cells. This work has been published in Sci Rep. 2015 Jul 24;5:12448. doi: 10.1038/srep12448.
Project description:This SuperSeries is composed of the following subset Series:; GSE1831: Temporal analysis of P15 hippocampus in kainate-induced seizures. Koh-2K08NS002068-04; GSE1834: Temporal analysis of hippocampus in kainate-induced seizures. Koh-7K08NS002068-05-3 Experiment Overall Design: Refer to individual Series
Project description:Sudden unexplained death in childhood (SUDC) is death of a child over one year of age that is unexplained after review of clinical history, circumstances of death, and complete autopsy with ancillary testing. Multiple etiologies may cause SUDC, with parallels to sudden unexpected death in epilepsy (SUDEP) in SUDC with a history of febrile seizures, suggesting possible abnormalities in hippocampus and cortex. To identify molecular signaling pathways underlying SUDC, we performed label-free quantitative mass spectrometry on microdissected frontal cortex, hippocampal dentate gyrus (DG), and cornu ammonis (CA1-3) in SUDC (n=19) and pediatric control cases (n=19) with an explained cause of death.
