Project description:Mesial temporal lobe epilepsy (MTLE) is the most common type of focal seizure disorder. In MTLE, seizures typically originate from a sclerotic hippocampus. Approximately one-third of patients do not respond to anti-seizure drugs and have few effective therapeutic options. Surgery to resect or ablate the affected temporal lobe is one such option, but it is not indicated or adequate for all individuals and can have adverse effects. Here, we report the development of an alternative cell therapy strategy for drug-resistant MTLE. The cell therapeutic is derived from a clinical-grade human embryonic stem cell line, and composed of cryopreserved post-mitotic medial ganglionic eminence (MGE)-type GABAergic inhibitory neurons of a predominantly pallial interneuron lineage. Single-dose intrahippocampal delivery of cryopreserved human pallial interneurons in a chronic mouse model of drug-resistant MTLE resulted in consistent and stable suppression of mesiotemporal seizures, with most animals becoming seizure-free. The grafted human interneurons distributed locally, matured, and persisted in the sclerotic hippocampus throughout the 8.5-month study. Pathological hallmarks of MTLE, such as hippocampal granule cell dispersion and sclerosis, were significantly reduced, and epileptic animal survival rates increased, after administration of the human interneurons. Suppression of seizure activity and amelioration of neuropathology were dose-dependent and suggested a broad therapeutic dosing range. No ectopic tissue or teratoma formation was detected after cell transplantation. Furthermore, behavioral abnormalities were not observed at any dose on a battery of assays. These findings support further development of human pallial MGE-type GABAergic interneuron cell therapy for the treatment of drug-resistant focal epilepsies.
Project description:We identified diffuse lesions made of BRAF V600E-mutant CD34-immunopositive stellar cells in human samples resected to cure drug-resistant focal epilepsy. We performed single-nuclei RNAseq 5' 10X on three human brain samples (two BRAF mutant samples and one BRAF wildtype sample as control) in order to identify the molecular phenotype of CD34+ cells.
Project description:Gene regulatory elements such as enhancers dynamically regulate gene expression in a tissue-specific manner. However, the transcriptional regulatory elements during human inhibitory interneuron differentiation and their role in neurodevelopmental disorders are unknown. Here, we generate gene regulatory element maps of human inhibitory-like interneurons derived from embryonic stem cells (H9-ESC), permitting large-scale annotation of previously uncharacterized regulatory elements relevant to inhibitory interneuron differentiation. Our analyses identify neuronal progenitor enhancers that likely regulate the expression of transcription factors that are essential for interneuron differentiation. Focusing on dynamic changes in chromatin organization, FOXG1 and ZEB2, where the chromatin organization is changed in interneuron progenitors compared to different stages during the differentiation. Using 4C-seq and an in vivo enhancer assay, we characterized neuronal enhancers at the FOXG1 locus that interact with the FOXG1 promoter region and showed activity patterns that resemble FOXG1 expression. Using CRISPR/Cas9 genome editing, we deleted FOXG1 enhancer/s that reduced FOXG1 expression in glioblastoma cells and altered cell proliferation. Furthermore, a microdeletion proximal to FOXG1 encompassing these neuronal FOXG1 enhancers was found in a patient with Rett-like syndrome, supporting the role of FOXG1 enhancers in this syndrome. Thus, our study elucidates the gene regulatory networks of human inhibitory interneurons. Furthermore, it provides a framework for understanding the impact of non-coding regulatory elements during inhibitory interneuron differentiation, and highlights novel mechanisms underlying neurodevelopmental disorders.
Project description:Analysis of biopsy hippocampal tissue of patients with pharmacoresistant temporal lobe epilepsy (TLE) undergoing neurosurgical removal of the epileptogenic focus for seizure control. Chronic TLE goes along with focal hyperexcitability. Results provide insight into molecular mechanisms that may play a role in seizure propensity 150 human hippocampus samples
Project description:Analysis of biopsy hippocampal tissue of patients with pharmacoresistant temporal lobe epilepsy (TLE) undergoing neurosurgical removal of the epileptogenic focus for seizure control. Chronic TLE goes along with focal hyperexcitability. Results provide insight into molecular mechanisms that may play a role in seizure propensity
Project description:CpG methylation analysis of MeDIP DNA using Agilent Human DNA methylation Microarray slides (G4495A, AMADID 023795) Using methylated DNA immunoprecipitation microarray (MeDIP-chip) and Agilent Human DNA methylation Microarray slides (G4495A, AMADID 023795) we report genomic methylation signatures of tissues resected from Mesial temporal epilepsy (MTLE) and Focal cortical dysplasia (FCD) type II patients undergoing surgery. Control samples were obtained from the non-epileptic post mortem cases without any brain pathology
Project description:Inhibitory GABAergic interneurons originate in the embryonic medial ganglionic eminence (MGE) and control network activity in the neocortex. Dysfunction of these cells is believed to lead to runaway excitation underlying seizure-based neurological disorders such as epilepsy, autism and schizophrenia. Despite their importance in heath and disease, our knowledge about the development of this diverse neuronal population remains incomplete. Here we conducted single cell RNA sequencing (scRNA-seq) of human fetal MGE from 10 to 15 weeks post conception. These MGE tissues are composed of largely cycling progenitors and immature post-mitotic interneurons with characteristic regional marker expression. Analysis of integrated human and mouse MGE data revealed species conserved transcriptomic profiles and regulatory program. Moreover, we identified novel candidate transcription regulators for human interneuron differentiation. These findings provide a framework for in vitro modelling of interneuron development and strategy for potentially enhance interneurons production from human pluripotent stem cells.
Project description:Explore DNA methylation in focal amygdala stimulation model of epilepsy and its relationship to gene expression. Examination of methylation changes in stimulated rats compared to sham operated animals in focal amygdala stimulation model of epilepsy.