Project description:The human neocortex is composed of dozens to hundreds of distinct cell types, whose gene expression patterns maintain the balanced electric signaling during all the life. Although the brain has shown a high adaptive capacity to tolerate disruptions, some alterations in these genetic programs can contribute to the pathogenesis of various neurological disorders, including epilepsy, autism spectrum disorder, Alzheimer’s disease, and Parkinson’s disease. Genetic factors are especially implicated in a specific form known as refractory or drug-resistant epilepsy (DRE), which is diagnosed when two or more antiepileptic treatment regimens fail to control seizures. In this study, we investigated the cellular and molecular landscape of DRE using brain tissue from five pediatric Colombian patients. Six samples collected during surgical resection were analyzed using single-cell RNA sequencing (scRNA-seq) and long-read genome sequencing (PacBio HiFi). We identified differentially expressed genes (DEGs) across distinct cell types, integrating transcriptomic data with single nucleotide polymorphisms (SNPs), insertions, deletions, and structural variants. Functional enrichment analysis revealed glial-driven dysregulation of synaptic signaling, impaired glial–neuronal communication, and altered expression of transporters and calcium signaling genes. Notably, aberrant activation of taste receptors in neurons was associated with neuroinflammatory processes. These findings suggest that DRE arises from complex, cell-type-specific disruptions that compromise network stability and seizure control.
2025-08-04 | GSE302285 | GEO
Project description:Genomics of Refractory Epilepsy (RE) patients in Colombia.
Project description:Introduction: The relationship between epilepsy and cognitive dysfunction has been investigated in canines, and memory impairment was prevalent in dogs with epilepsy. There is some evidence that canines with epilepsy have greater amyloid-β (Aβ) accumulation and neuronal degeneration than healthy controls. The present study investigated plasma Aβ42 levels and performed proteomic profiling in dogs with refractory epilepsy and healthy dogs. Methods: In total, eight dogs, including four healthy dogs and four dogs with epilepsy, were included in the study. Blood samples were collected to analyze Aβ42 levels and perform proteomic profiling. Changes in the plasma proteomic profiles of dogs were determined by nano LC-MS/MS. Results and discussion: The plasma Aβ42 level was significantly higher in dogs with epilepsy (99 pg/mL) than in healthy dogs (5.9 pg/mL). In total, 155 proteins were identified, and of these, the expression of 40 proteins was altered in epilepsy. Among these proteins, which are linked to neurodegenerative diseases, 10 (25%) were downregulated in dogs with epilepsy, whereas 12 (30%) were upregulated. The expression of the acute phase proteins haptoglobin and α2-macroglobulin significantly differed between the groups. Complement factor H and ceruloplasmin were only detected in epilepsy dogs, suggesting that neuroinflammation plays a role in epileptic seizures. Gelsolin, which is involved in cellular processes and cytoskeletal organization, was only detected in healthy dogs. Gene Ontology annotation revealed that epilepsy can potentially interfere with biological processes, including cellular processes, localization, and responses to stimuli. Seizures compromised key molecular functions, including catalytic activity, molecular function regulation, and binding. Defense/immunity proteins were most significantly modified during the development of epilepsy. In Kyoto Encyclopedia of Genes and Genomes pathway analysis, complement and coagulation cascades were the most relevant signaling pathways affected by seizures. The findings suggested that haptoglobin, ceruloplasmin, α2-macroglobulin, complement factor H, and gelsolin play roles in canine epilepsy and Aβ levels based on proteomic profiling. These proteins could represent diagnostic biomarkers that, after clinical validation, could be used in veterinary practice as well as proteins relevant to disease response pathways. To determine the precise mechanisms underlying these relationships and their implications in canine epilepsy, additional research is required.
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:The role of human glia in many neurological disorders is still poorly understood due to the lack of tools that reliably isolate specific glial subpopulations from bulk tissue, directly from their native niche. To better understand the contributions of glial pathology in human epilepsy, we developed and validated a novel sorting strategy that simultaneously isolates nuclei populations of astrocytes (PAX6+), oligodendroglial progenitors (OPCs) (OLIG2+) and neurons (NEUN+) from non-pathological fresh-frozen human postmortem temporal neocortex brain tissue (TL Control) and then employed it, in combination with single cell RNA-seq, to characterize the cell-type specific transcriptome alterations in epilepsy temporal neocortex derived from fresh surgical material in patients with medically refractory temporal lobe epilepsy (TLE).
Project description:This study was performed to test the hypothesis that systemic leukocyte gene expression has prognostic value differentiating low from high seizure frequency refractory temporal lobe epilepsy (TLE). A consecutive series of sixteen patients with refractory temporal lobe epilepsy was studied. Based on a median baseline seizure frequency of 2.0 seizures per month, low versus high seizure frequency was defined as < 2 seizures/month and > 2 seizures/month, respectively.
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:MicroRNAs (miRNAs) have been found to participate in the pathogenesis of several neurological diseases including epilepsy. To date, the expression and functions of miRNAs in chronic temporal lobe epilepsy (TLE), the most common type of refractory epilepsy in adults, have not been well characterized. Here, we adopted high-throughput sequencing to investigate miRNA expression profile in a chronic TLE model induced by amygdala stimulation
Project description:Temporal lobe epilepsy is one of the most common refractory epilepsies in the world. Epilepsy progression is controlled through the expression of epilepsy permissive genes, ultimately resulting in a hyperexcitable network and spontaneous seizures. DNA methylation has been explored as a potential epigenetic regulatory mechanism of gene expression in epilepsy, however, the role of 5-hydroxymethylcytosine (5-hmC) has been underexplored to date. 5-hmC is a stable epigenetic mark most abundantly expressed in the brain. In this study, we show that 5-hmC but not 5-methylcytosine (5-mC) is lost in temporal lobe epilepsy. Using 5-hmC meDIP-sequencing, we characterized epileptic 5-hmC distribution in the rat kainic acid model of temporal lobe epilepsy. We identified the correlation of 5-hmC loss and gain with epilepsy-associated gene ontology pathways and implicate the potential involvement of multiple cell types with 5-hmC regulation of temporal lobe epilepsy. Overall, we show that 5-hmC has the potential to be a crucial regulator of epilepsy and epileptic gene expression and are the first to characterize the genomic distribution of 5-hmC in a model of epilepsy.
Project description:Most humans are infected with Epstein-Barr virus (EBV), a cancer-causing virus. While EBV generally persists silently in B lymphocytes, periodic lytic (re-)activation of latent virus is central to its life cycle and to most EBV-related diseases. However, a substantial fraction of EBV-infected B cells and tumor cells in a population is refractory to lytic activation. This resistance to lytic activation directly and profoundly impacts viral persistence and effectiveness of oncolytic therapy for EBV+ cancers. To identify the mechanisms that underlie susceptibility to EBV-lytic activation, we used host protein-expression profiling of separated-lytic and -refractory cells.