Development of an antiseizure drug screening platform for Dravet syndrome at the NINDS contract site for the Epilepsy Therapy Screening Program.
Ontology highlight
ABSTRACT: Objective
Dravet syndrome (DS) is a rare but catastrophic genetic epilepsy, with 80% of patients carrying a mutation in the SCN1A gene. Currently, no antiseizure drug (ASD) exists that adequately controls seizures. In the clinic, individuals with DS often present first with a febrile seizure and, subsequently, generalized tonic-clonic seizures that can continue throughout life. To facilitate the development of ASDs for DS, the contract site of the National Institute of Neurological Disorders and Stroke (NINDS) Epilepsy Therapy Screening Program (ETSP) has evaluated a mouse model of DS using the conditional knock-in Scn1aA1783V/WT mouse.Methods
Survival rates and temperature thresholds for Scn1aA1783V/WT were determined. Prototype ASDs were administered via intraperitoneal injections at the time-to-peak effect, which was previously determined, prior to the induction of hyperthermia-induced seizures. ASDs were considered effective if they significantly increased the temperature at which Scn1aA1783V/WT mice had seizures.Results
Approximately 50% of Scn1aA1783V/WT survive to adulthood and all have hyperthermia-induced seizures. The results suggest that hyperthermia-induced seizures in this model of DS are highly refractory to a battery of ASDs. Exceptions were clobazam, tiagabine, levetiracetam, and the combination of clobazam and valproic acid with add-on stiripentol, which elevated seizure thresholds.Significance
Overall, the data demonstrate that the proposed model for DS is suitable for screening novel compounds for the ability to block hyperthermia-induced seizures and that heterozygous mice can be evaluated repeatedly over the course of several weeks, allowing for higher throughput screening.
SUBMITTER: Pernici CD
PROVIDER: S-EPMC8360068 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:ObjectiveEpilepsy treatment falls short in ~30% of cases. A better understanding of epilepsy pathophysiology can guide rational drug development in this difficult to treat condition. We tested a low-cost, drug-repositioning strategy to identify candidate epilepsy drugs that are already FDA-approved and might be immediately tested in epilepsy patients who require new therapies.MethodsBiopsies of spiking and nonspiking hippocampal brain tissue from six patients with unilateral mesial temporal lobe epilepsy were analyzed by RNA-Seq. These profiles were correlated with transcriptomes from cell lines treated with FDA-approved drugs, identifying compounds which were tested for therapeutic efficacy in a zebrafish seizure assay.ResultsIn spiking versus nonspiking biopsies, RNA-Seq identified 689 differentially expressed genes, 148 of which were previously cited in articles mentioning seizures or epilepsy. Differentially expressed genes were highly enriched for protein-protein interactions and formed three clusters with associated GO-terms including myelination, protein ubiquitination, and neuronal migration. Among the 184 compounds, a zebrafish seizure model tested the therapeutic efficacy of doxycycline, metformin, nifedipine, and pyrantel tartrate, with metformin, nifedipine, and pyrantel tartrate all showing efficacy.InterpretationThis proof-of-principle analysis suggests our powerful, rapid, cost-effective approach can likely be applied to other hard-to-treat diseases.
| S-EPMC6389756 | biostudies-literature
Project description:The ketogenic diet (KD) is an anticonvulsant treatment that has been used to manage medically-intractable epilepsies. The KD requires 10-12 days to become maximally effective, suggesting that changes in gene expression are involved in its anticonvulsant action. Using the Affymetrix rat arrays (RAE230A), 6 control samples and 5 KD samples were run. Keywords: other
2004-03-29 | GSE1155 | GEO
Project description:Severe myoclonic epilepsy of infancy (SMEI), or Dravet syndrome (DS), is a catastrophic pediatric epilepsy with severe intellectual disability, impaired social development, and persistent drug-resistant seizures. One of its primary monogenic causes is a mutation in SCN1A (Nav1.1), a type I voltage-gated sodium channel. In mice, Nav1.1 mutation is associated with reduced sodium current, altered interneuron firing, cognitive deficits, autistic-like traits and seizures. Here we describe a larval zebrafish Nav1.1 mutant that recapitulates salient features of the human SCN1A mutation phenotype. Between three and seven days post-fertilization, Nav1.1 mutants exhibit spontaneous abnormal electrographic activity, hyperactivity and convulsive behaviors. Transcriptomic analysis of Nav1.1 mutants was remarkable for the relatively small fraction of genes that were differentially expressed (~2%) and the lack of compensatory changes in expression for other SCN subunits. Pharmacological studies confirmed an antiepileptic action for the ketogenic diet, benzodiazepine, valproate, potassium bromide and stiripentol in Nav1.1 mutants; acetazolamide, phenytoin, ethosuximide had no effect, carbamazepine and vigabatrin made seizures worse. Using this mutant, we screened a chemical library of 320 compounds and identified four compounds that reduced spontaneous seizure-like behavior and one compound (clemizole) that inhibited convulsive behavior and electrographic seizures. Drug-resistant scn1a zebrafish mutants described here represent a new direction in modeling pediatric epilepsy and could be used to identify novel lead compounds for DS patients 4 Control sibling samples (sample= 10 pooled larvae) and 4 Nav1.1 mutants (sample= 10 pooled larvae) were collected at 6 dpf (days post fertilization). The Nav1.1 mutants were selected based on phenotype (dark color).
2014-01-04 | E-GEOD-43312 | biostudies-arrayexpress
Project description:Severe myoclonic epilepsy of infancy (SMEI), or Dravet syndrome (DS), is a catastrophic pediatric epilepsy with severe intellectual disability, impaired social development, and persistent drug-resistant seizures. One of its primary monogenic causes is a mutation in SCN1A (Nav1.1), a type I voltage-gated sodium channel. In mice, Nav1.1 mutation is associated with reduced sodium current, altered interneuron firing, cognitive deficits, autistic-like traits and seizures. Here we describe a larval zebrafish Nav1.1 mutant that recapitulates salient features of the human SCN1A mutation phenotype. Between three and seven days post-fertilization, Nav1.1 mutants exhibit spontaneous abnormal electrographic activity, hyperactivity and convulsive behaviors. Transcriptomic analysis of Nav1.1 mutants was remarkable for the relatively small fraction of genes that were differentially expressed (~2%) and the lack of compensatory changes in expression for other SCN subunits. Pharmacological studies confirmed an antiepileptic action for the ketogenic diet, benzodiazepine, valproate, potassium bromide and stiripentol in Nav1.1 mutants; acetazolamide, phenytoin, ethosuximide had no effect, carbamazepine and vigabatrin made seizures worse. Using this mutant, we screened a chemical library of 320 compounds and identified four compounds that reduced spontaneous seizure-like behavior and one compound (clemizole) that inhibited convulsive behavior and electrographic seizures. Drug-resistant scn1a zebrafish mutants described here represent a new direction in modeling pediatric epilepsy and could be used to identify novel lead compounds for DS patients
2014-01-04 | GSE43312 | GEO
Project description:ObjectiveTo gather real-world evidence on antiseizure medications (ASMs) treatment patterns and related outcomes in patients with drug-resistant focal epilepsy.MethodsMedical insurance claims from the start of 2014 till the end of 2019 were used. Patient selection criteria included International Classification of Diseases (ICD) codes followed by documented ASM use. Baseline patient demographics along with ASM and rescue medication use patterns and related patient outcome were documented for first (index) ASM regimen. Patients who failed the first regimen and then failed the second regimen were considered drug resistant. Multivariate analyses were performed to identify risks and other characteristics for positive or negative treatment outcomes.ResultsStudy cohort consisted of 46 474 patients with a mean age of 47.23 (SD: 16.94). Levetiracetam was the most first-encountered ASM (37.94%). At baseline, 87.14% were treated with ASMs prior to having study-confirmed diagnoses. Mental comorbidities were present in 37.86% of patients. After first-year ASM treatment, 34.61% of patients persisted on their index regimen and 5.91% were seizure-free. Patients failing first ASM regimen numbered 12 868 (27.69%). Drug-resistant patients who failed first and then second ASM regimens numbered 6335 (49.23%). Percentages of patients who had successful second treatment and seizure-free were 21.32 and 3.65, respectively. Initiating patients on lamotrigine or carbamazepine (relative to levetiracetam), baseline use of index ASM, rescue medications, and older age or male gender all lowered the risk for treatment failure. Having higher comorbidity, comorbid mental illness, headache, or neoplasty increased such a risk. Baseline use of index ASM, depressive episode, or anxiety disorder all entailed higher risk of failing second ASM treatment.SignificanceOverall, reported findings indicated that patient history at baseline and the early selection of an ASM all influenced treatment outcomes. Findings pointed to the complex nature of ASM treatment in drug-resistant focal epilepsy patients calling for additional research to identify the optimal treatment to achieve beneficial patient outcomes.
| S-EPMC10690664 | biostudies-literature
Project description:ImportanceThere is little evidence to guide the choice of antiseizure medication (ASM) for patients with poststroke epilepsy. Theoretical concerns about detrimental effects of ASMs on survival exist. Enzyme-inducing drugs could interfere with secondary stroke prevention. The US Food and Drug Administration recently issued a safety announcement about the potential proarrhythmic properties of lamotrigine.ObjectiveTo investigate whether mortality varies with specific ASMs among patients with poststroke epilepsy.Design, setting, and participantsA cohort study was conducted using individual-level data from linked registers on all adults in Sweden with acute stroke from July 1, 2005, to December 31, 2010, and subsequent onset of epilepsy before December 31, 2014. A total of 2577 patients receiving continuous ASM monotherapy were eligible for the study. Data were analyzed between May 27, 2019, and April 8, 2021.ExposuresThe dispensed ASM (Anatomical Therapeutic Chemical code N03A) determined exposure status, and the first dispensation date marked the start of treatment.Main outcomes and measuresThe primary outcome, all-cause death, was analyzed using Cox proportional hazards regression with carbamazepine as the reference. Cardiovascular death (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes I0-I99 as the underlying cause) was assessed using Fine-Gray competing risk regression models.ResultsA total of 2577 patients (1400 men [54%]; median age, 78 years [IQR, 69-85 years]) were included. The adjusted hazard ratio of all-cause death compared with carbamazepine was 0.72 (95% CI, 0.60-0.86) for lamotrigine, 0.96 (95% CI, 0.80-1.15) for levetiracetam, 1.40 (95% CI, 1.23-1.59) for valproic acid, 1.16 (95% CI, 0.88-1.51) for phenytoin, and 1.16 (95% CI, 0.81-1.66) for oxcarbazepine. The adjusted hazard ratio of cardiovascular death compared with carbamazepine was 0.76 (95% CI, 0.61-0.95) for lamotrigine, 0.77 (95% CI, 0.60-0.99) for levetiracetam, 1.40 (95% CI, 1.19-1.64) for valproic acid, 1.02 (95% CI, 0.71-1.47) for phenytoin, and 0.71 (95% CI, 0.42-1.18) for oxcarbazepine.Conclusions and relevanceThis cohort study's findings suggest differences in survival between patients treated with different ASMs for poststroke epilepsy. Patients receiving lamotrigine monotherapy had significantly lower mortality compared with those receiving carbamazepine. The opposite applied to patients prescribed valproic acid, who had a higher risk of cardiovascular and all-cause death. Levetiracetam was associated with a reduced risk of cardiovascular death compared with carbamazepine, but there was no significant difference in overall mortality.
| S-EPMC8669603 | biostudies-literature
Project description:BackgroundNeuroprotection for Parkinson's disease (PD) remains elusive. Biomarkers hold the promise of removing roadblocks to therapy development. The National Institute of Neurological Disorders and Stroke has therefore established the Parkinson's Disease Biomarkers Program to promote discovery of PD biomarkers for use in phase II and III clinical trials.MethodsUsing a novel consortium design, the Parkinson's Disease Biomarker Program is focused on the development of clinical and laboratory-based biomarkers for PD diagnosis, progression, and prognosis. Standardized operating procedures and pooled reference samples were created to allow cross-project comparisons and assessment of batch effects. A web-based Data Management Resource facilitates rapid sharing of data and biosamples across the research community for additional biomarker projects.ResultsEleven consortium projects are ongoing, seven of which recruit participants and obtain biosamples. As of October 2014, 1,082 participants have enrolled (620 PD, 101 with other causes of parkinsonism, 23 essential tremor, and 338 controls), 1,040 of whom have at least one biosample. Six thousand eight hundred ninety-eight total biosamples are available from baseline, 6-, 12-, and 18-month visits: 1,006 DNA, 1,661 RNA, 1,419 whole blood, 1,382 plasma, 1,200 serum, and 230 cerebrospinal fluid (CSF). Quality control analysis of plasma, serum, and CSF samples indicates that almost all samples are high quality (24 of 2,812 samples exceed acceptable hemoglobin levels).ConclusionsBy making samples and data widely available, using stringent operating procedures based on existing standards, hypothesis testing for biomarker discovery, and providing a resource that complements existing programs, the Parkinson's Disease Biomarker Program will accelerate the pace of PD biomarker research. © 2015 International Parkinson and Movement Disorder Society.
| S-EPMC4824671 | biostudies-literature
Project description:The zebrafish model has emerged as a reference tool for phenotypic drug screening. An increasing number of molecules have been brought from bench to bedside thanks to zebrafish-based assays over the last decade. The high homology between the zebrafish and the human genomes facilitates the generation of zebrafish lines carrying loss-of-function mutations in disease-relevant genes; nonetheless, even using this alternative model, the establishment of isogenic mutant lines requires a long generation time and an elevated number of animals. In this study, we developed a zebrafish-based high-throughput platform for the generation of F0 knock-out (KO) models and the screening of neuroactive compounds. We show that the simultaneous inactivation of a reporter gene (tyrosinase) and a second gene of interest allows the phenotypic selection of F0 somatic mutants (crispants) carrying the highest rates of mutations in both loci. As a proof of principle, we targeted genes associated with neurodevelopmental disorders and we efficiently generated de facto F0 mutants in seven genes involved in childhood epilepsy. We employed a high-throughput multiparametric behavioral analysis to characterize the response of these KO models to an epileptogenic stimulus, making it possible to employ kinematic parameters to identify seizure-like events. The combination of these co-injection, screening and phenotyping methods allowed us to generate crispants recapitulating epilepsy features and to test the efficacy of compounds already during the first days post fertilization. Since the strategy can be applied to a wide range of indications, this study paves the ground for high-throughput drug discovery and promotes the use of zebrafish in personalized medicine and neurotoxicity assessment.
| S-EPMC10931767 | biostudies-literature
Project description:Epilepsy is a common chronic neurological disease affecting almost 3 million people in the United States and 50 million people worldwide. Despite availability of more than two dozen FDA-approved anti-epileptic drugs (AEDs), one-third of patients fail to receive adequate seizure control. Specifically, pediatric genetic epilepsies are often the most severe, debilitating and pharmaco-resistant forms of epilepsy. Epileptic syndromes share a common symptom of unprovoked seizures. While some epilepsies/forms of epilepsy are the result of acquired insults such as head trauma, febrile seizure, or viral infection, others have a genetic basis. The discovery of epilepsy associated genes suggests varied underlying pathologies and opens the door for development of new "personalized" treatment options for each genetic epilepsy. Among these, Dravet syndrome (DS) has received substantial attention for both the pre-clinical and early clinical development of novel therapeutics. Despite these advances, there is no FDA-approved treatment for DS. Over 80% of patients diagnosed with DS carry a de novo mutation within the voltage-gated sodium channel gene SCN1A and these patients suffer with drug resistant and life-threatening seizures. Here we will review the preclinical animal models for DS featuring inactivation of SCN1A (including zebrafish and mice) with an emphasis on seizure phenotypes and behavioral comorbidities. Because many drugs fail somewhere between initial preclinical discovery and clinical trials, it is equally important that we understand how these models respond to known AEDs. As such, we will also review the available literature and recent drug screening efforts using these models with a focus on assay protocols and predictive pharmacological profiles. Validation of these preclinical models is a critical step in our efforts to efficiently discover new therapies for these patients. The behavioral and electrophysiological drug screening assays in zebrafish will be discussed in detail including specific examples from our laboratory using a zebrafish scn1 mutant and a summary of the nearly 3000 drugs screened to date. As the discovery and development phase rapidly moves from the lab-to-the-clinic for DS, it is hoped that this preclinical strategy offers a platform for how to approach any genetic epilepsy.
| S-EPMC5994396 | biostudies-literature
Project description:ObjectiveAtaluren is a compound that reads through premature stop codons and increases protein expression by increasing translation without modifying transcription or mRNA stability. We investigated the safety and efficacy of ataluren in children with nonsense variants causing Dravet Syndrome (DS) and CDKL5 Deficiency Syndrome (CDD).MethodsThis single-center double-blind, placebo-controlled crossover trial randomized subjects to receive ataluren or placebo for 12 weeks (period 1), a 4-week washout, then another 12-week treatment (period 2). The primary outcome was ataluren's safety profile. The secondary outcome measures were (1) changes in convulsive and/or drop seizure frequency and (2) changes in minor seizure types during ataluren treatment compared to placebo. Exploratory objectives assessed changes in cognitive, motor, and behavioral function as well as quality of life during ataluren therapy.ResultsWe enrolled seven subjects with DS and eight subjects with CDD. Three treatment-related adverse events (AE) occurred during the blinded phases. Two subjects withdrew due to AE. Ataluren was not effective in reducing seizure frequency or improving cognitive, motor, or behavioral function or quality of life in subjects with either DS or CDD due to nonsense variants. Limitations included a small sample size and 12-week treatment phase, possibly too short to identify a disease-modifying effect.SignificanceThere was no difference between ataluren and placebo; ataluren is not an effective therapy for seizures or other disorders in children with DS or CDD due to nonsense variants. There were no drug-related serious AE during the double-blind period, consistent with ataluren's favorable safety profile in larger studies. (Funded by Epilepsy Foundation, Dravet Syndrome Foundation, Finding A Cure for Seizures and Epilepsy and PTC Therapeutics, Inc.; ClinicalTrials.gov number, NCT02758626).
| S-EPMC7951093 | biostudies-literature