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Lian J, Lin Z, Li X, Chen G, Wu D. Different dosage regimens of zuranolone in the treatment of major depressive disorder: A meta-analysis of randomized controlled trials. J Affect Disord 2024; 354:206-215. [PMID: 38479510 DOI: 10.1016/j.jad.2024.03.057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 02/06/2024] [Accepted: 03/09/2024] [Indexed: 03/21/2024]
Abstract
OBJECTIVE To investigate the efficacy and safety of different dosage regimens of zuranolone in the treatment of patients with major depressive disorder (MDD). METHODS PubMed, Embase, The Cochrane Library and other databases were searched from inception until July 2019. Randomized controlled trials (RCTs) related to the efficacy and safety of zuranolone in the treatment of MDD were included. The data were extracted independently by 2 investigators and assessed the study quality by the Cochrane risk-of-bias tool. The primary outcome includes the 17-item HAMILTON total score (HAMD-17) and the incidence of adverse events (AEs). RESULTS Six high-quality RCTs with 1593 patients were finally included in our analysis. Zuranolone group achieve a notable treatment effect at day15 in HAMD-17 compared with placebo group (MD = -2.69, 95 % CI: -4.45 to -0.94, P < 0.05). For safety, no significant differences existed in the proportion of patients with AEs between zuranolone with placebo (RR = 1.25, 95 % CI: 0.99 to 1.58, P = 0.06). CONCLUSION Zuranolone has a significant efficacy in improving depressive symptoms in the short term and is positively correlated with the dosage administered. However, the efficacy of zuranolone decreased significantly when the time of administration was extended. Zuranolone demonstrated a controllable safety issue. But adverse effects increased as the dose of zuranolone was gradually increased to 50 mg.
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Affiliation(s)
- Jinrong Lian
- Department of Clinical Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Zhimin Lin
- Department of Clinical Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Xiang Li
- Department of Clinical Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Gang Chen
- Department of Clinical Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China.
| | - Depei Wu
- Department of Clinical Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China.
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2
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Mich JK, Ryu J, Wei AD, Gore BB, Guo R, Bard AM, Martinez RA, Bishaw Y, Luber E, Oliveira Santos LM, Miranda N, Ramirez JM, Ting JT, Lein ES, Levi BP, Kalume FK. AAV-mediated interneuron-specific gene replacement for Dravet syndrome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.15.571820. [PMID: 38168178 PMCID: PMC10760176 DOI: 10.1101/2023.12.15.571820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Dravet syndrome (DS) is a devastating developmental epileptic encephalopathy marked by treatment-resistant seizures, developmental delay, intellectual disability, motor deficits, and a 10-20% rate of premature death. Most DS patients harbor loss-of-function mutations in one copy of SCN1A , which has been associated with inhibitory neuron dysfunction. Here we developed an interneuron-targeting AAV human SCN1A gene replacement therapy using cell class-specific enhancers. We generated a split-intein fusion form of SCN1A to circumvent AAV packaging limitations and deliver SCN1A via a dual vector approach using cell class-specific enhancers. These constructs produced full-length Na V 1.1 protein and functional sodium channels in HEK293 cells and in brain cells in vivo . After packaging these vectors into enhancer-AAVs and administering to mice, immunohistochemical analyses showed telencephalic GABAergic interneuron-specific and dose-dependent transgene biodistribution. These vectors conferred strong dose-dependent protection against postnatal mortality and seizures in two DS mouse models carrying independent loss-of-function alleles of Scn1a, at two independent research sites, supporting the robustness of this approach. No mortality or toxicity was observed in wild-type mice injected with single vectors expressing either the N-terminal or C-terminal halves of SCN1A , or the dual vector system targeting interneurons. In contrast, nonselective neuronal targeting of SCN1A conferred less rescue against mortality and presented substantial preweaning lethality. These findings demonstrate proof-of-concept that interneuron-specific AAV-mediated SCN1A gene replacement is sufficient for significant rescue in DS mouse models and suggest it could be an effective therapeutic approach for patients with DS.
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3
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Suvekbala V, Ramachandran H, Veluchamy A, Mascarenhas MAB, Ramprasath T, Nair MKC, Garikipati VNS, Gundamaraju R, Subbiah R. The Promising Epigenetic Regulators for Refractory Epilepsy: An Adventurous Road Ahead. Neuromolecular Med 2022:10.1007/s12017-022-08723-0. [DOI: 10.1007/s12017-022-08723-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 07/13/2022] [Indexed: 10/14/2022]
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4
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Balan I, Aurelian L, Williams KS, Campbell B, Meeker RB, Morrow AL. Inhibition of human macrophage activation via pregnane neurosteroid interactions with toll-like receptors: Sex differences and structural requirements. Front Immunol 2022; 13:940095. [PMID: 35967446 PMCID: PMC9373802 DOI: 10.3389/fimmu.2022.940095] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 07/07/2022] [Indexed: 11/13/2022] Open
Abstract
We recently discovered that (3α,5α)3-hydroxypregnan-20-one (allopregnanolone) inhibits pro-inflammatory toll-like receptor (TLR) activation and cytokine/chemokine production in mouse macrophage RAW264.7 cells. The present studies evaluate neurosteroid actions upon TLR activation in human macrophages from male and female healthy donors. Buffy coat leukocytes were obtained from donors at the New York Blood Center (http://nybloodcenter.org/), and peripheral blood mononuclear cells were isolated and cultured to achieve macrophage differentiation. TLR4 and TLR7 were activated by lipopolysaccharide (LPS) or imiquimod in the presence/absence of allopregnanolone or related neurosteroids and pro-inflammatory markers were detected by ELISA or western blotting. Cultured human monocyte-derived-macrophages exhibited typical morphology, a mixed immune profile of both inflammatory and anti-inflammatory markers, with no sex difference at baseline. Allopregnanolone inhibited TLR4 activation in male and female donors, preventing LPS-induced elevations of TNF-α, MCP-1, pCREB and pSTAT1. In contrast, 3α,5α-THDOC and SGE-516 inhibited the TLR4 pathway activation in female, but not male donors. Allopregnanolone completely inhibited TLR7 activation by imiquimod, blocking IL-1-β, IL-6, pSTAT1 and pIRF7 elevations in females only. 3α,5α-THDOC and SGE-516 partially inhibited TLR7 activation, only in female donors. The results indicate that allopregnanolone inhibits TLR4 and TLR7 activation in cultured human macrophages resulting in diminished cytokine/chemokine production. Allopregnanolone inhibition of TLR4 activation was found in males and females, but inhibition of TLR7 signals exhibited specificity for female donors. 3α,5α-THDOC and SGE-516 inhibited TLR4 and TLR7 pathways only in females. These studies demonstrate anti-inflammatory effects of allopregnanolone in human macrophages for the first time and suggest that inhibition of pro-inflammatory cytokines/chemokines may contribute to its therapeutic actions.
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Affiliation(s)
- Irina Balan
- Department of Psychiatry, Department of Pharmacology, Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, NC, United States
| | - Laure Aurelian
- Stanford University School of Medicine, Stanford, CA, United States
| | - Kimberly S. Williams
- Department of Neurology, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, NC, United States
| | - Brian Campbell
- Translational Sciences, Sage Therapeutics Inc., Cambridge, MA, United States
| | - Rick B. Meeker
- Department of Neurology, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, NC, United States
| | - A. Leslie Morrow
- Department of Psychiatry, Department of Pharmacology, Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, NC, United States
- *Correspondence: A. Leslie Morrow,
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Goisis RC, Chiavegato A, Gomez-Gonzalo M, Marcon I, Requie LM, Scholze P, Carmignoto G, Losi G. GABA tonic currents and glial cells are altered during epileptogenesis in a mouse model of Dravet syndrome. Front Cell Neurosci 2022; 16:919493. [PMID: 35936501 PMCID: PMC9350930 DOI: 10.3389/fncel.2022.919493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 06/28/2022] [Indexed: 11/17/2022] Open
Abstract
Dravet Syndrome (DS) is a rare autosomic encephalopathy with epilepsy linked to Nav1.1 channel mutations and defective GABAergic signaling. Effective therapies for this syndrome are lacking, urging a better comprehension of the mechanisms involved. In a recognized mouse model of DS, we studied GABA tonic current, a form of inhibition largely neglected in DS, in brain slices from developing mice before spontaneous seizures are reported. In neurons from the temporal cortex (TeCx) and CA1 region, GABA tonic current was reduced in DS mice compared to controls, while in the entorhinal cortex (ECx) it was not affected. In this region however allopregnanonole potentiation of GABA tonic current was reduced in DS mice, suggesting altered extrasynaptic GABAA subunits. Using THIP as a selective agonist, we found reduced δ subunit mediated tonic currents in ECx of DS mice. Unexpectedly in the dentate gyrus (DG), a region with high δ subunit expression, THIP-evoked currents in DS mice were larger than in controls. An immunofluorescence study confirmed that δ subunit expression was reduced in ECx and increased in DG of DS mice. Finally, considering the importance of neuroinflammation in epilepsy and neurodevelopmental disorders, we evaluated classical markers of glia activation. Our results show that DS mice have increased Iba1 reactivity and GFAP expression in both ECx and DG, compared to controls. Altogether we report that before spontaneous seizures, DS mice develop significant alterations of GABA tonic currents and glial cell activation. Understanding all the mechanisms involved in these alterations during disease maturation and progression may unveil new therapeutic targets.
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Affiliation(s)
- Rosa Chiara Goisis
- Department of Biomedical Science, University of Padua, Padua, Italy
- Neuroscience Institute, National Research Council (IN-CNR), Padua, Italy
| | - Angela Chiavegato
- Neuroscience Institute, National Research Council (IN-CNR), Padua, Italy
| | - Marta Gomez-Gonzalo
- Department of Biomedical Science, University of Padua, Padua, Italy
- Neuroscience Institute, National Research Council (IN-CNR), Padua, Italy
| | - Iacopo Marcon
- Department of Biomedical Science, University of Padua, Padua, Italy
| | | | - Petra Scholze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Giorgio Carmignoto
- Department of Biomedical Science, University of Padua, Padua, Italy
- Neuroscience Institute, National Research Council (IN-CNR), Padua, Italy
| | - Gabriele Losi
- Department of Biomedical Science, University of Padua, Padua, Italy
- Neuroscience Institute, National Research Council (IN-CNR), Padua, Italy
- *Correspondence: Gabriele Losi
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Tanenhaus A, Stowe T, Young A, McLaughlin J, Aeran R, Lin IW, Li J, Hosur R, Chen M, Leedy J, Chou T, Pillay S, Vila MC, Kearney JA, Moorhead M, Belle A, Tagliatela S. Cell-Selective Adeno-Associated Virus-Mediated SCN1A Gene Regulation Therapy Rescues Mortality and Seizure Phenotypes in a Dravet Syndrome Mouse Model and Is Well Tolerated in Nonhuman Primates. Hum Gene Ther 2022; 33:579-597. [PMID: 35435735 PMCID: PMC9242722 DOI: 10.1089/hum.2022.037] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Dravet syndrome (DS) is a developmental and epileptic encephalopathy caused by monoallelic loss-of-function variants in the SCN1A gene. SCN1A encodes for the alpha subunit of the voltage-gated type I sodium channel (NaV1.1), the primary voltage-gated sodium channel responsible for generation of action potentials in GABAergic inhibitory interneurons. In these studies, we tested the efficacy of an adeno-associated virus serotype 9 (AAV9) SCN1A gene regulation therapy, AAV9-REGABA-eTFSCN1A, designed to target transgene expression to GABAergic inhibitory neurons and reduce off-target expression within excitatory cells, in the Scn1a+/- mouse model of DS. Biodistribution and preliminary safety were evaluated in nonhuman primates (NHPs). AAV9-REGABA-eTFSCN1A was engineered to upregulate SCN1A expression levels within GABAergic inhibitory interneurons to correct the underlying haploinsufficiency and circuit dysfunction. A single bilateral intracerebroventricular (ICV) injection of AAV9-REGABA-eTFSCN1A in Scn1a+/- postnatal day 1 mice led to increased SCN1A mRNA transcripts, specifically within GABAergic inhibitory interneurons, and NaV1.1 protein levels in the brain. This was associated with a significant decrease in the occurrence of spontaneous and hyperthermia-induced seizures, and prolonged survival for over a year. In NHPs, delivery of AAV9-REGABA-eTFSCN1A by unilateral ICV injection led to widespread vector biodistribution and transgene expression throughout the brain, including key structures involved in epilepsy and cognitive behaviors, such as hippocampus and cortex. AAV9-REGABA-eTFSCN1A was well tolerated, with no adverse events during administration, no detectable changes in clinical observations, no adverse findings in histopathology, and no dorsal root ganglion-related toxicity. Our results support the clinical development of AAV9-REGABA-eTFSCN1A (ETX101) as an effective and targeted disease-modifying approach to SCN1A+ DS.
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Affiliation(s)
- Annie Tanenhaus
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Timothy Stowe
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Andrew Young
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - John McLaughlin
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Rangoli Aeran
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - I. Winnie Lin
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Jianmin Li
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | | | - Ming Chen
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Jennifer Leedy
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Tiffany Chou
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Sirika Pillay
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | | | - Jennifer A. Kearney
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Martin Moorhead
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Archana Belle
- Encoded Therapeutics, Inc., South San Francisco, California, USA
| | - Stephanie Tagliatela
- Encoded Therapeutics, Inc., South San Francisco, California, USA.,Correspondence: Stephanie Tagliatela, Encoded Therapeutics, Inc., 341 Oyster Point Boulevard, South San Francisco, CA 94080, USA.
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7
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Cerne R, Lippa A, Poe MM, Smith JL, Jin X, Ping X, Golani LK, Cook JM, Witkin JM. GABAkines - Advances in the discovery, development, and commercialization of positive allosteric modulators of GABA A receptors. Pharmacol Ther 2022; 234:108035. [PMID: 34793859 PMCID: PMC9787737 DOI: 10.1016/j.pharmthera.2021.108035] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 11/08/2021] [Indexed: 12/25/2022]
Abstract
Positive allosteric modulators of γ-aminobutyric acid-A (GABAA) receptors or GABAkines have been widely used medicines for over 70 years for anxiety, epilepsy, sleep, and other disorders. Traditional GABAkines like diazepam have safety and tolerability concerns that include sedation, motor-impairment, respiratory depression, tolerance and dependence. Multiple GABAkines have entered clinical development but the issue of side-effects has not been fully solved. The compounds that are presently being developed and commercialized include several neuroactive steroids (an allopregnanolone formulation (brexanolone), an allopregnanolone prodrug (LYT-300), Sage-324, zuranolone, and ganaxolone), the α2/3-preferring GABAkine, KRM-II-81, and the α2/3/5-preferring GABAkine PF-06372865 (darigabat). The neuroactive steroids are in clinical development for post-partum depression, intractable epilepsy, tremor, status epilepticus, and genetic epilepsy disorders. Darigabat is in development for epilepsy and anxiety. The imidazodiazepine, KRM-II-81 is efficacious in animal models for the treatment of epilepsy and post-traumatic epilepsy, acute and chronic pain, as well as anxiety and depression. The efficacy of KRM-II-81 in models of pharmacoresistant epilepsy, preventing the development of seizure sensitization, and in brain tissue of intractable epileptic patients bodes well for improved therapeutics. Medicinal chemistry efforts are also ongoing to identify novel and improved GABAkines. The data document gaps in our understanding of the molecular pharmacology of GABAkines that drive differential pharmacological profiles, but emphasize advancements in the ability to successfully utilize GABAA receptor potentiation for therapeutic gain in neurology and psychiatry.
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Affiliation(s)
- Rok Cerne
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent, Indianapolis, IN USA,Faculty of Medicine, University of Ljubljana, Zaloška cesta 4, Ljubljana, Slovenia.,RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA,Department of Anatomy and Cell Biology, Indiana University/Purdue University, Indianapolis, IN, USA
| | - Arnold Lippa
- RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA
| | | | - Jodi L. Smith
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent, Indianapolis, IN USA
| | - Xiaoming Jin
- Department of Anatomy and Cell Biology, Indiana University/Purdue University, Indianapolis, IN, USA
| | - Xingjie Ping
- Department of Anatomy and Cell Biology, Indiana University/Purdue University, Indianapolis, IN, USA
| | - Lalit K. Golani
- Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - James M. Cook
- RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA,Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Jeffrey M. Witkin
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent, Indianapolis, IN USA,RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA,Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
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8
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Hawkins NA, Jurado M, Thaxton TT, Duarte SE, Barse L, Tatsukawa T, Yamakawa K, Nishi T, Kondo S, Miyamoto M, Abrahams BS, During MJ, Kearney JA. Soticlestat, a novel cholesterol 24-hydroxylase inhibitor, reduces seizures and premature death in Dravet syndrome mice. Epilepsia 2021; 62:2845-2857. [PMID: 34510432 PMCID: PMC9291096 DOI: 10.1111/epi.17062] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/23/2021] [Accepted: 08/23/2021] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Dravet syndrome is a severe developmental and epileptic encephalopathy (DEE) most often caused by de novo pathogenic variants in SCN1A. Individuals with Dravet syndrome rarely achieve seizure control and have significantly elevated risk for sudden unexplained death in epilepsy (SUDEP). Heterozygous deletion of Scn1a in mice (Scn1a+/- ) recapitulates several core phenotypes, including temperature-dependent and spontaneous seizures, SUDEP, and behavioral abnormalities. Furthermore, Scn1a+/- mice exhibit a similar clinical response to standard anticonvulsants. Cholesterol 24-hydroxlase (CH24H) is a brain-specific enzyme responsible for cholesterol catabolism. Recent research has indicated the therapeutic potential of CH24H inhibition for diseases associated with neural excitation, including seizures. METHODS In this study, the novel compound soticlestat, a CH24H inhibitor, was administered to Scn1a+/- mice to investigate its ability to improve Dravet-like phenotypes in this preclinical model. RESULTS Soticlestat treatment reduced seizure burden, protected against hyperthermia-induced seizures, and completely prevented SUDEP in Scn1a+/- mice. Video-electroencephalography (EEG) analysis confirmed the ability of soticlestat to reduce occurrence of electroclinical seizures. SIGNIFICANCE This study demonstrates that soticlestat-mediated inhibition of CH24H provides therapeutic benefit for the treatment of Dravet syndrome in mice and has the potential for treatment of DEEs.
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Affiliation(s)
- Nicole A Hawkins
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Manuel Jurado
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Tyler T Thaxton
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Samantha E Duarte
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Levi Barse
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Tetsuya Tatsukawa
- Laboratory for Neurogenetics, RIKEN Brain Science Institute, Wako, Japan
| | - Kazuhiro Yamakawa
- Laboratory for Neurogenetics, RIKEN Brain Science Institute, Wako, Japan
| | - Toshiya Nishi
- Neuroscience Drug Discovery Unit, Takeda Pharmaceutical Ltd, Fujisawa, Japan
| | - Shinichi Kondo
- Neuroscience Drug Discovery Unit, Takeda Pharmaceutical Ltd, Fujisawa, Japan
| | - Maki Miyamoto
- Neuroscience Drug Discovery Unit, Takeda Pharmaceutical Ltd, Fujisawa, Japan
| | | | | | - Jennifer A Kearney
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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Martin P, Reeder T, Sourbron J, de Witte PAM, Gammaitoni AR, Galer BS. An Emerging Role for Sigma-1 Receptors in the Treatment of Developmental and Epileptic Encephalopathies. Int J Mol Sci 2021; 22:8416. [PMID: 34445144 PMCID: PMC8395113 DOI: 10.3390/ijms22168416] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/30/2021] [Accepted: 08/03/2021] [Indexed: 12/14/2022] Open
Abstract
Developmental and epileptic encephalopathies (DEEs) are complex conditions characterized primarily by seizures associated with neurodevelopmental and motor deficits. Recent evidence supports sigma-1 receptor modulation in both neuroprotection and antiseizure activity, suggesting that sigma-1 receptors may play a role in the pathogenesis of DEEs, and that targeting this receptor has the potential to positively impact both seizures and non-seizure outcomes in these disorders. Recent studies have demonstrated that the antiseizure medication fenfluramine, a serotonin-releasing drug that also acts as a positive modulator of sigma-1 receptors, reduces seizures and improves everyday executive functions (behavior, emotions, cognition) in patients with Dravet syndrome and Lennox-Gastaut syndrome. Here, we review the evidence for sigma-1 activity in reducing seizure frequency and promoting neuroprotection in the context of DEE pathophysiology and clinical presentation, using fenfluramine as a case example. Challenges and opportunities for future research include developing appropriate models for evaluating sigma-1 receptors in these syndromic epileptic conditions with multisystem involvement and complex clinical presentation.
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Affiliation(s)
- Parthena Martin
- Zogenix, Inc., Emeryville, CA 94608, USA; (P.M.); (T.R.); (A.R.G.)
| | - Thadd Reeder
- Zogenix, Inc., Emeryville, CA 94608, USA; (P.M.); (T.R.); (A.R.G.)
| | - Jo Sourbron
- University Hospital KU Leuven, 3000 Leuven, Belgium;
| | - Peter A. M. de Witte
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences at KU Leuven, 3000 Leuven, Belgium;
| | | | - Bradley S. Galer
- Zogenix, Inc., Emeryville, CA 94608, USA; (P.M.); (T.R.); (A.R.G.)
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10
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Pernici CD, Mensah JA, Dahle EJ, Johnson KJ, Handy L, Buxton L, Smith MD, West PJ, Metcalf CS, Wilcox KS. Development of an antiseizure drug screening platform for Dravet syndrome at the NINDS contract site for the Epilepsy Therapy Screening Program. Epilepsia 2021; 62:1665-1676. [PMID: 34002394 PMCID: PMC8360068 DOI: 10.1111/epi.16925] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 04/25/2021] [Accepted: 04/27/2021] [Indexed: 02/06/2023]
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.
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Affiliation(s)
- Chelsea D. Pernici
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Jeffrey A. Mensah
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - E. Jill Dahle
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Kristina J. Johnson
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
| | - Laura Handy
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
| | - Lauren Buxton
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Misty D. Smith
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Peter J. West
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Cameron S. Metcalf
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Karen S. Wilcox
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
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Abstract
Pathogenic variants in epilepsy genes result in a spectrum of clinical severity. One source of phenotypic heterogeneity is modifier genes that affect expressivity of a primary pathogenic variant. Mouse epilepsy models also display varying degrees of clinical severity on different genetic backgrounds. Mice with heterozygous deletion of Scn1a (Scn1a+/−) model Dravet syndrome, a severe epilepsy most often caused by SCN1A haploinsufficiency. Scn1a+/− mice recapitulate features of Dravet syndrome, including spontaneous seizures, sudden death, and cognitive/behavioral deficits. Scn1a+/− mice maintained on the 129S6/SvEvTac (129) strain have normal lifespan and no spontaneous seizures. In contrast, admixture with C57BL/6J (B6) results in epilepsy and premature lethality. We previously mapped Dravet Survival Modifier loci (Dsm1-Dsm5) responsible for strain-dependent differences in survival. Gabra2, encoding the GABAA α2 subunit, was nominated as a candidate modifier at Dsm1. Direct measurement of GABAA receptors found lower abundance of α2-containing receptors in hippocampal synapses of B6 mice relative to 129. We also identified a B6-specific single nucleotide deletion within Gabra2 that lowers mRNA and protein by nearly 50%. Repair of this deletion reestablished normal levels of Gabra2 expression. In this study, we used B6 mice with a repaired Gabra2 allele to evaluate Gabra2 as a genetic modifier of severity in Scn1a+/− mice. Gabra2 repair restored transcript and protein expression, increased abundance of α2-containing GABAA receptors in hippocampal synapses, and rescued epilepsy phenotypes of Scn1a+/− mice. These findings validate Gabra2 as a genetic modifier of Dravet syndrome, and support enhancing function of α2-containing GABAA receptors as treatment strategy for Dravet syndrome.
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12
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Mantegazza M, Cestèle S, Catterall WA. Sodium channelopathies of skeletal muscle and brain. Physiol Rev 2021; 101:1633-1689. [PMID: 33769100 DOI: 10.1152/physrev.00025.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Voltage-gated sodium channels initiate action potentials in nerve, skeletal muscle, and other electrically excitable cells. Mutations in them cause a wide range of diseases. These channelopathy mutations affect every aspect of sodium channel function, including voltage sensing, voltage-dependent activation, ion conductance, fast and slow inactivation, and both biosynthesis and assembly. Mutations that cause different forms of periodic paralysis in skeletal muscle were discovered first and have provided a template for understanding structure, function, and pathophysiology at the molecular level. More recent work has revealed multiple sodium channelopathies in the brain. Here we review the well-characterized genetics and pathophysiology of the periodic paralyses of skeletal muscle and then use this information as a foundation for advancing our understanding of mutations in the structurally homologous α-subunits of brain sodium channels that cause epilepsy, migraine, autism, and related comorbidities. We include studies based on molecular and structural biology, cell biology and physiology, pharmacology, and mouse genetics. Our review reveals unexpected connections among these different types of sodium channelopathies.
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Affiliation(s)
- Massimo Mantegazza
- Université Cote d'Azur, Valbonne-Sophia Antipolis, France.,CNRS UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne-Sophia Antipolis, France.,INSERM, Valbonne-Sophia Antipolis, France
| | - Sandrine Cestèle
- Université Cote d'Azur, Valbonne-Sophia Antipolis, France.,CNRS UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne-Sophia Antipolis, France
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13
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Miziak B, Czuczwar S. Advances in the design and discovery of novel small molecule drugs for the treatment of Dravet Syndrome. Expert Opin Drug Discov 2020; 16:579-593. [PMID: 33275464 DOI: 10.1080/17460441.2021.1857722] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Introduction: Dravet syndrome (severe myoclonic epilepsy in infancy) begins in the first year of life characterized by generalized or unilateral clonic seizures that are frequently triggered by high fever. A subsequent worsening stage occurs (in years 1-4 of life) and seizure activity is accompanied by disturbed psychomotor development. The third stage of the disease, known as the 'stabilization phase,' is associated with seizures and intellectual impairment. Of note, a mutation in the voltage-gated sodium-channel gene α 1 subunit (SCN1A) has been found in around 85% of patients with Dravet syndrome.Areas covered: The authors review the current treatment strategies as well as potential drugs in the initial stages of clinical evaluation. The authors also review drugs with protective activity in mice models of Dravet syndrome.Expert opinion: Experimental data and results from initial clinical studies have brought attention to several drugs with various mechanisms of action including: ataluren (a suppressant of premature stop codons; under clinical evaluation), EPX-100, EPX-200, fenfluramine (serotonin modulators), soticlestat (an 24-hydroxylase cholesterol enzyme inhibitor), SPN-817 (an inhibitor of acetylcholinesterase), verapamil (a voltage-dependent calcium channel inhibitor) and STK-001 (an antisense oligonucleotide). The latter is scheduled for clinical evaluation.
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Affiliation(s)
- Barbara Miziak
- Department of Pathophysiology, Medical University of Lublin, Lublin, Poland
| | - Stanisław Czuczwar
- Department of Pathophysiology, Medical University of Lublin, Lublin, Poland
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14
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Bialer M, Johannessen SI, Koepp MJ, Levy RH, Perucca E, Perucca P, Tomson T, White HS. Progress report on new antiepileptic drugs: A summary of the Fifteenth Eilat Conference on New Antiepileptic Drugs and Devices (EILAT XV). II. Drugs in more advanced clinical development. Epilepsia 2020; 61:2365-2385. [PMID: 33165915 DOI: 10.1111/epi.16726] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/20/2020] [Accepted: 09/21/2020] [Indexed: 12/16/2022]
Abstract
The Fifteenth Eilat Conference on New Antiepileptic Drugs and Devices (EILAT XV) was held as a fully virtual conference from July 27 to July 30, 2020 for the sessions on drugs, and on August 3, 2020 for the sessions on devices. A total of 534 delegates from 63 countries attended lectures and interactive discussions, representing a broad range of disciplines from basic science, clinical research, and clinical care. This progress report provides summaries of recent findings on investigational compounds for which preclinical data as well as data from patient studies were presented. The report includes the following five compounds: anakinra, cenobamate, CVL-865, fenfluramine, and ganaxolone, all with novel modes of action compared to more established antiepileptic drugs. Some of these compounds demonstrated promising results in placebo-controlled phase 3 trials, and two have recently received approval from the US Food and Drug Administration (FDA). These include cenobamate, which was approved by the FDA on November 21, 2019 for the treatment of partial onset (focal) seizures in adults, and fenfluramine oral solution, which was approved by the FDA on June 25, 2020 for the treatment of seizures associated with Dravet syndrome in patients 2 years and older.
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Affiliation(s)
- Meir Bialer
- Faculty of Medicine, School of Pharmacy and David R. Bloom Center for Pharmacy, Institute for Drug Research, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Svein I Johannessen
- National Center for Epilepsy, Sandvika, Norway.,Department of Pharmacology, Oslo University Hospital, Oslo, Norway
| | - Matthias J Koepp
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK
| | - René H Levy
- Department of Pharmaceutics and Neurological Surgery, University of Washington, Seattle, WA, USA
| | - Emilio Perucca
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy.,IRCCS Mondino Foundation, Pavia, Italy
| | - Piero Perucca
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Department of Medicine and Neurology, Royal Melbourne Hospital, University of Melbourne, Melbourne, Victoria, Australia.,Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
| | - Torbjörn Tomson
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - H Steve White
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA, USA
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15
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Althaus AL, Ackley MA, Belfort GM, Gee SM, Dai J, Nguyen DP, Kazdoba TM, Modgil A, Davies PA, Moss SJ, Salituro FG, Hoffmann E, Hammond RS, Robichaud AJ, Quirk MC, Doherty JJ. Preclinical characterization of zuranolone (SAGE-217), a selective neuroactive steroid GABA A receptor positive allosteric modulator. Neuropharmacology 2020; 181:108333. [PMID: 32976892 PMCID: PMC8265595 DOI: 10.1016/j.neuropharm.2020.108333] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 08/26/2020] [Accepted: 09/18/2020] [Indexed: 01/04/2023]
Abstract
Zuranolone (SAGE-217) is a novel, synthetic, clinical stage neuroactive steroid GABAA receptor positive allosteric modulator designed with the pharmacokinetic properties to support oral daily dosing. In vitro, zuranolone enhanced GABAA receptor current at nine unique human recombinant receptor subtypes, including representative receptors for both synaptic (γ subunit-containing) and extrasynaptic (δ subunit-containing) configurations. At a representative synaptic subunit configuration, α1β2γ2, zuranolone potentiated GABA currents synergistically with the benzodiazepine diazepam, consistent with the non-competitive activity and distinct binding sites of the two classes of compounds at synaptic receptors. In a brain slice preparation, zuranolone produced a sustained increase in GABA currents consistent with metabotropic trafficking of GABAA receptors to the cell surface. In vivo, zuranolone exhibited potent activity, indicating its ability to modulate GABAA receptors in the central nervous system after oral dosing by protecting against chemo-convulsant seizures in a mouse model and enhancing electroencephalogram β-frequency power in rats. Together, these data establish zuranolone as a potent and efficacious neuroactive steroid GABAA receptor positive allosteric modulator with drug-like properties and CNS exposure in preclinical models. Recent clinical data support the therapeutic promise of neuroactive steroid GABAA receptor positive modulators for treating mood disorders; brexanolone is the first therapeutic approved specifically for the treatment of postpartum depression. Zuranolone is currently under clinical investigation for the treatment of major depressive episodes in major depressive disorder, postpartum depression, and bipolar depression.
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Affiliation(s)
- Alison L Althaus
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA.
| | - Michael A Ackley
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Gabriel M Belfort
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Steven M Gee
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Jing Dai
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - David P Nguyen
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Tatiana M Kazdoba
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Amit Modgil
- Department of Neuroscience, Tufts University, Boston, MA, USA
| | - Paul A Davies
- Department of Neuroscience, Tufts University, Boston, MA, USA
| | - Stephen J Moss
- Department of Neuroscience, Tufts University, Boston, MA, USA
| | - Francesco G Salituro
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Ethan Hoffmann
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Rebecca S Hammond
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Albert J Robichaud
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - Michael C Quirk
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
| | - James J Doherty
- Research and Nonclinical Development, Sage Therapeutics, Inc., Cambridge, MA, USA
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16
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Hatini PG, Commons KG. A 5-HT 1D -receptor agonist protects Dravet syndrome mice from seizure and early death. Eur J Neurosci 2020; 52:4370-4374. [PMID: 32394465 DOI: 10.1111/ejn.14776] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/20/2020] [Accepted: 05/03/2020] [Indexed: 12/27/2022]
Abstract
Mutations in the SCN1A gene encoding the Nav1.1 sodium channel cause several forms of epilepsy, the most severe is Dravet syndrome (DS). DS patients are at high risk for sudden death and seizures are often triggered by fever or hyperthermia. To improve understanding of how serotonergic ligands might influence DS in this study, we tested several drugs for their effect on hyperthermia-induced seizure using a mouse model of DS consisting of a heterozygous loss of function of Scn1A. We found that a mixed 5-HT2A/2C receptor agonist had no effect while a mixed 5-HT1B/D receptor agonist had a modest effect reducing the severity of seizures. Hypothesizing selective agonists may be more effective, we tested selective 5-HT1B and 5-HT1D receptor agonists, CP-93129 and GR-46611, respectively. Of these GR-46611 significantly increased the threshold of hyperthermia-induced seizure and lowered seizure severity. Given chronically at 1 mg kg-1 day-1 , GR-46611 also significantly improved survival of DS mice. Thus, 5-HT1D -receptors may represent a meaningful target for pharmacotherapy for DS with potential relevance for related forms of epilepsy, particularly those with a known sensory trigger such as heat.
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Affiliation(s)
- Paul G Hatini
- Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, USA
| | - Kathryn G Commons
- Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts, USA
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17
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Martin P, de Witte PAM, Maurice T, Gammaitoni A, Farfel G, Galer B. Fenfluramine acts as a positive modulator of sigma-1 receptors. Epilepsy Behav 2020; 105:106989. [PMID: 32169824 DOI: 10.1016/j.yebeh.2020.106989] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/10/2020] [Accepted: 02/17/2020] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Adjunctive fenfluramine hydrochloride, classically described as acting pharmacologically through a serotonergic mechanism, has demonstrated a unique and robust clinical response profile with regard to its magnitude, consistency, and durability of effect on seizure activity in patients with pharmacoresistant Dravet syndrome. Recent findings also support long-term improvements in executive functions (behavior, emotion, cognition) in these patients. The observed clinical profile is inconsistent with serotonergic activity alone, as other serotonergic medications have not been demonstrated to have these clinical effects. This study investigated a potential role for σ1 receptor activity in complementing fenfluramine's serotonergic pharmacology. METHODS Radioligand binding assays tested the affinity of fenfluramine for 47 receptors associated with seizures in the literature, including σ receptors. Cellular function assays tested fenfluramine and norfenfluramine (its major metabolite) activity at various receptors, including adrenergic, muscarinic, and serotonergic receptors. The σ1 receptor activity was assessed by the mouse vas deferens isometric twitch and by an assay of dissociation of the σ1 receptor from the endoplasmic reticulum stress protein binding immunoglobulin protein (BiP). In vivo mouse models assessed fenfluramine activity at σ1 receptors in ameliorating dizocilpine-induced learning deficits in spatial and nonspatial memory tasks, alone or in combination with the reference σ1 receptor agonist PRE-084. RESULTS Fenfluramine and norfenfluramine bound ≥30% to β2-adrenergic, muscarinic M1, serotonergic 5-HT1A, and σ receptors, as well as sodium channels, with a Ki between 266 nM (σ receptors) and 17.5 μM (β-adrenergic receptors). However, only σ1 receptor isometric twitch assays showed a positive functional response, with weak stimulation by fenfluramine and inhibition by norfenfluramine. Fenfluramine, but not the 5-HT2C agonist lorcaserin, showed a positive modulation of the PRE-084-induced dissociation of σ1 protein from BiP. Fenfluramine also showed dose-dependent antiamnesic effects against dizocilpine-induced learning deficits in spontaneous alternation and passive avoidance responses, which are models of σ1 activation. Moreover, low doses of fenfluramine synergistically potentiated the low-dose effect of PRE-084, confirming a positive modulatory effect at the σ1 receptor. Finally, all in vivo effects were blocked by the σ1 receptor antagonist NE-100. SIGNIFICANCE Fenfluramine demonstrated modulatory activity at σ1 receptors in vitro and in vivo in addition to its known serotonergic activity. These studies identify a possible new σ1 receptor mechanism underpinning fenfluramine's central nervous system effects, which may contribute to its antiseizure activity in Dravet syndrome and positive effects observed on executive functions in clinical studies.
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Affiliation(s)
| | - Peter A M de Witte
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.
| | - Tangui Maurice
- MMDN, University of Montpellier, INSERM, EPHE, UMR_S1198, Montpellier, France.
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18
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Kang SK, Hawkins NA, Kearney JA. C57BL/6J and C57BL/6N substrains differentially influence phenotype severity in the Scn1a +/- mouse model of Dravet syndrome. Epilepsia Open 2019; 4:164-169. [PMID: 30868126 PMCID: PMC6398090 DOI: 10.1002/epi4.12287] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/05/2018] [Accepted: 11/13/2018] [Indexed: 01/01/2023] Open
Abstract
Many disease-relevant phenotypes modeled in inbred mice have been shown to be strain-dependent, indicating the important influence of genetic background on disease phenotypes. Although C57BL/6 mice are one of the most commonly used inbred strains in laboratory research, there are multiple substrains (eg, B6J vs B6N) that have been separated for more than 50 years. Thus, understanding the substrain differences is important for scientific rigor and reproducibility. In this study, seizure susceptibility, spontaneous seizures, and survival were compared between Scn1a +/- mice on (C57BL/6J × 129S6/SvEvTac)F1 (F1J) vs (C57BL/6N × 129S6/SvEvTac)F1 (F1N) strain backgrounds. F1N.Scn1a +/- mice were more susceptible to hyperthermia-induced seizures, yet had milder spontaneous seizures and improved survival relative to F1J.Scn1a +/- mice. Our results indicate that choice of C57BL/6 substrain may significantly alter disease phenotypes and should be considered carefully in experimental design using the Scn1a +/- Dravet mouse model, as well as other mouse models of epilepsy.
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Affiliation(s)
- Seok K. Kang
- Interdepartmental Neuroscience ProgramFeinberg School of MedicineNorthwestern UniversityChicagoIllinois
| | - Nicole A. Hawkins
- Department of PharmacologyFeinberg School of MedicineNorthwestern UniversityChicagoIllinois
| | - Jennifer A. Kearney
- Interdepartmental Neuroscience ProgramFeinberg School of MedicineNorthwestern UniversityChicagoIllinois
- Department of PharmacologyFeinberg School of MedicineNorthwestern UniversityChicagoIllinois
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19
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Melón L, Hammond R, Lewis M, Maguire J. A Novel, Synthetic, Neuroactive Steroid Is Effective at Decreasing Depression-Like Behaviors and Improving Maternal Care in Preclinical Models of Postpartum Depression. Front Endocrinol (Lausanne) 2018; 9:703. [PMID: 30532739 PMCID: PMC6265503 DOI: 10.3389/fendo.2018.00703] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 11/08/2018] [Indexed: 12/21/2022] Open
Abstract
Preclinical testing of treatments for postpartum depression (PPD) has been limited due to the lack of available animal models of such a complex disorder. To address this limitation, our laboratory has generated unique preclinical mouse models that exhibit abnormal postpartum behaviors. Mice with a loss or reduction in the expression of the GABAA receptor (GABAAR) δ subunit (Gabrd -/- or Gabrd +/-, respectively) and mice that lack the K+/Cl- co-transporter, KCC2, specifically in corticotropin-releasing hormone (CRH) neurons (KCC2/Crh mice) exhibit depression-like behaviors restricted to the postpartum period and deficits in maternal care, which serve as useful tools for testing novel therapeutic compounds. Utilizing these preclinical models, we tested the ability of a novel, synthetic, neuroactive steroid developed by SAGE Therapeutics, SGE-516, to improve abnormal postpartum behaviors. Gabrd -/-, Gabrd +/-, and KCC2/Crh dams treated with SGE-516 (450 mg/kg chow) during late pregnancy exhibit a decrease in depression-like behaviors and improvements in maternal care at 48 h postpartum. Interestingly, acute treatment with SGE-516 also exhibits robust therapeutic effects in these preclinical PPD models. We previously discovered abnormal stress reactivity associated with hypothalamic-pituitary-adrenal (HPA) axis dysregulation associated with depression-like behaviors in the preclinical PPD models, evident from an increase in stress-induced corticosterone levels and dephosphorylation and downregulation of KCC2 in the paraventricular nucleus of the hypothalamus (PVN) during the peripartum period. Here we demonstrated that SGE-516 treatment is sufficient to prevent the stress-induced increase in corticosterone and dephosphorylation and downregulation of KCC2 in the PVN. In contrast, and consistent with the distinct pharmacology of SGE-516 compared to benzodiazepines, treatment with clobazam (250 mg/kg chow) did not alter the depression-like phenotype or deficits in maternal care observed in these preclinical models of PPD. These findings are consistent with the positive double-blind, randomized, placebo-controlled trial findings of a similar compound, brexanolone, in the treatment of patients with postpartum depression. Further, these findings validate the use of these preclinical models of PPD for screening novel compounds for the treatment of postpartum depression.
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Affiliation(s)
- Laverne Melón
- TEACRS Program, Tufts University School of Medicine, Boston, MA, United States
| | | | - Mike Lewis
- SAGE Therapeutics, Cambridge, MA, United States
| | - Jamie Maguire
- Neuroscience Department, Tufts University School of Medicine, Boston, MA, United States
- *Correspondence: Jamie Maguire
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