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: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:This study sought to investigate temporal changes in hippocampal gene co-expression networks during the development of rats submitted to hyperthermic seizures
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: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:Febrile seizures (FS) are the most common type of seizures in young children. Complex FS are a risk factor for mesial temporal lobe epilepsy (mTLE). Twin studies and mutations in families with complex epilepsy syndromes including FS, indicate a genetic contribution to FS susceptibility. By employing a phenotype driven genetic strategy using consomics we mapped a quantitative trait locus (QTL) for hyperthermia-induced FS susceptibility on mouse chromosome 1. Signal Recognition Particle 9 (Srp9) in the QTL was differentially expressed between parental strains, and its binding partner Srp14 was co-identified as a strong candidate gene in another FS susceptibility QTL. The SRP complex plays a key role in the synthesis of membrane proteins, such as glutamate receptors. In vivo knock-down of brain Srp9 or inhibition of protein synthesis reduced FS susceptibility. The mouse strain (CSS1) with reduced Srp9 expression and FS susceptibility, exhibited reduced hippocampal AMPA and NMDA currents. Down-regulation of Srp9 in hippocampal neurons reduced surface expression of AMPA receptor subunit GluA1. Consistent with a role of SRP9 in human FS, we detected increased hippocampal SRP9 expression in mTLE patients with antecedent FS. Comparing mTLE patients and healthy controls we found an association of a SRP9 promoter SNP (rs12403575 G/A) with FS and mTLE, which was replicated in FS patients. Our findings identify SRP9 as a novel FS susceptibility gene and implicate ER-dependent protein synthesis and glutamate receptor expression in the mechanism.
