1
|
Downs J, Jacoby P, Specchio N, Cross H, Amin S, Bahi-Buisson N, Rajaraman R, Suter B, Devinsky O, Aimetti A, Busse G, Olson HE, Demarest S, Benke TA, Pestana-Knight E. Effects of ganaxolone on non-seizure outcomes in CDKL5 Deficiency Disorder: Double-blind placebo-controlled randomized trial. Eur J Paediatr Neurol 2024; 51:140-146. [PMID: 38959712 PMCID: PMC11283350 DOI: 10.1016/j.ejpn.2024.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 04/22/2024] [Accepted: 06/16/2024] [Indexed: 07/05/2024]
Abstract
CDKL5 deficiency disorder (CDD) is a rare developmental and epileptic encephalopathy. Ganaxolone, a neuroactive steroid, reduces the frequency of major motor seizures in children with CDD. This analysis explored the effect of ganaxolone on non-seizure outcomes. Children (2-19 years) with genetically confirmed CDD and ≥ 16 major motor seizures per month were enrolled in a double-blind randomized placebo-controlled trial. Ganaxolone or placebo was administered three times daily for 17 weeks. Behaviour was measured with the Anxiety, Depression and Mood Scale (ADAMS), daytime sleepiness with the Child Health Sleep Questionnaire, and quality of life with the Quality of Life Inventory-Disability (QI-Disability) scale. Scores were compared using ANOVA, adjusted for age, sex, number of anti-seizure mediations, baseline 28-day major motor seizure frequency, baseline developmental skills, and behaviour, sleep or quality of life scores. 101 children with CDD (39 clinical sites, 8 countries) were randomized. Median (IQR) age was 6 (3-10) years, 79.2 % were female, and 50 received ganaxolone. After 17 weeks of treatment, Manic/Hyperactive scores (mean difference 1.27, 95%CI -2.38,-0.16) and Compulsive Behaviour scores (mean difference 0.58, 95%CI -1.14,-0.01) were lower (improved) in the ganaxolone group compared with the placebo group. Daytime sleepiness scores were similar between groups. The total change in QOL score for children in the ganaxolone group was 2.6 points (95%CI -1.74,7.02) higher (improved) than in the placebo group but without statistical significance. Along with better seizure control, children who received ganaxolone had improved behavioural scores in select domains compared to placebo.
Collapse
Affiliation(s)
- J Downs
- Telethon Kids Institute, The University of Western Australia, Australia; Curtin School of Allied Health, Curtin University, Perth, Australia.
| | - P Jacoby
- Telethon Kids Institute, The University of Western Australia, Australia
| | - N Specchio
- Rare and Complex Epilepsy Unit, Department of Neuroscience, Bambino Gesù Children's Hospital IRCCS, Full Member of European Reference Network EpiCARE, Rome, Italy
| | - H Cross
- UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - S Amin
- Department of Paediatric Neurology, Bristol Royal Hospital for Children, Bristol, United Kingdom
| | - N Bahi-Buisson
- Pediatric Neurology, Necker Enfants Malades, Université de Paris, Paris, France
| | - R Rajaraman
- Division of Pediatric Neurology, David Geffen School of Medicine and UCLA Mattel Children's Hospital, Los Angeles, CA, USA
| | - B Suter
- Pediatrics & Neurology, Baylor College of Medicine & Texas Children's Hospital, Houston, USA
| | - O Devinsky
- Department of Neurology, New York University, New York, NY, USA
| | | | - G Busse
- Marinus Pharmaceuticals, Inc, USA
| | - H E Olson
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - S Demarest
- University of Colorado, Department of Pediatrics and Neurology, Children's Hospital Colorado, Aurora, CO, USA
| | - T A Benke
- Depts of Pediatrics, Pharmacology, Neurology and Otolaryngology, University of Colorado School of Medicine/Children's Hospital Colorado, Aurora, CO, USA
| | - E Pestana-Knight
- Charles Shor Epilepsy Center, Cleveland Clinic Neurological Institute, Cleveland, OH, USA
| |
Collapse
|
2
|
Huie EZ, Yang X, Rioult-Pedotti MS, Naik M, Huang YWA, Silverman JL, Marshall J. Peptidomimetic inhibitors targeting TrkB/PSD-95 signaling improves cognition and seizure outcomes in an Angelman Syndrome mouse model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.07.597833. [PMID: 38895218 PMCID: PMC11185757 DOI: 10.1101/2024.06.07.597833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Angelman syndrome (AS) is a rare genetic neurodevelopmental disorder with profoundly debilitating symptoms with no FDA-approved cure or therapeutic. Brain-derived neurotrophic factor (BDNF), and its receptor TrkB, have a well-established role as regulators of synaptic plasticity, dendritic outgrowth, dendritic spine formation and maintenance. Previously, we reported that the association of PSD-95 with TrkB is critical for intact BDNF signaling in the AS mouse model, as illustrated by attenuated PLCγ and PI3K signaling and intact MAPK pathway signaling. These data suggest that drugs tailored to enhance the TrkB-PSD-95 interaction may provide a novel approach for the treatment of AS and a variety of NDDs. To evaluate this critical interaction, we synthesized a class of high-affinity PSD-95 ligands that bind specifically to the PDZ3 domain of PSD-95, denoted as Syn3 peptidomimetic ligands. We evaluated Syn3 and its analog D-Syn3 (engineered using dextrorotary (D)-amino acids) in vivo using the Ube3a exon 2 deletion mouse model of AS. Following systemic administration of Syn3 and D-Syn3, we demonstrated improvement in the seizure domain of AS. Learning and memory using the novel object recognition assay also illustrated improved cognition following Syn3 and D-Syn3, along with restored long-term potentiation. Finally, D-Syn3 treated mice showed a partial rescue in motor learning. Neither Syn3 nor D-Syn3 improved gross exploratory locomotion deficits, nor gait impairments that have been well documented in the AS rodent models. These findings highlight the need for further investigation of this compound class as a potential therapeutic for AS and other genetic NDDs.
Collapse
|
3
|
Fitzgerald PJ. Neural hyperexcitability in Angelman syndrome: Genetic factors and pharmacologic treatment approaches. Epilepsy Res 2024; 200:107286. [PMID: 38217951 DOI: 10.1016/j.eplepsyres.2024.107286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 12/18/2023] [Accepted: 01/02/2024] [Indexed: 01/15/2024]
Abstract
Angelman syndrome (AS) is a rare neurodevelopmental disorder that is typically caused by deletion or a loss-of-function mutation of the maternal copy of the ubiquitin ligase E3A (UBE3A) gene. The disorder is characterized by severe intellectual disability, deficits in speech, motor abnormalities, altered electroencephalography (EEG) activity, spontaneous epileptic seizures, sleep disturbances, and a happy demeanor with frequent laughter. Regarding electrophysiologic abnormalities in particular, enhanced delta oscillatory power and an elevated excitatory/inhibitory (E/I) ratio have been documented in AS, with E/I ratio especially studied in rodent models. These electrophysiologic characteristics appear to relate with the greatly elevated rates of epilepsy in individuals with AS, and associated hypersynchronous neural activity. Here we briefly review findings on EEG, E/I ratio, and epileptic seizures in AS, including data from rodent models of the disorder. We summarize pharmacologic approaches that have been used to treat behavioral aspects of AS, including neuropsychiatric phenomena and sleep disturbances, as well as seizures in the context of the disorder. Antidepressants such as SSRIs and atypical antipsychotics are among the medications that have been used behaviorally, whereas anticonvulsant drugs such as valproic acid and lamotrigine have frequently been used to control seizures in AS. We end by suggesting novel uses for some existing pharmacologic agents in AS, including noradrenergic transmission reducing drugs (alpha2 agonists, beta blockers, alpha1 antagonists) and cholinesterase inhibitors, where these various classes of drugs may have the ability to ameliorate both behavioral disturbances and seizures.
Collapse
Affiliation(s)
- Paul J Fitzgerald
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, USA.
| |
Collapse
|
4
|
Neff MJ, Reddy DS. Long-Term Neuropsychiatric Developmental Defects after Neonatal Organophosphate Exposure: Mitigation by Synthetic Neurosteroids. J Pharmacol Exp Ther 2024; 388:451-468. [PMID: 37863488 PMCID: PMC10806574 DOI: 10.1124/jpet.123.001763] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 07/25/2023] [Accepted: 07/31/2023] [Indexed: 10/22/2023] Open
Abstract
Children are much more susceptible to the neurotoxic effects of organophosphate (OP) pesticides and nerve agents than adults. OP poisoning in children leads to acute seizures and neuropsychiatric sequela, including the development of long-term disabilities and cognitive impairments. Despite these risks, there are few chronic rodent models that use pediatric OP exposure for studying neurodevelopmental consequences and interventions. Here, we investigated the protective effect of the neurosteroid ganaxolone (GX) on the long-term developmental impact of neonatal exposure to the OP compound, diisopropyl-fluorophosphate (DFP). Pediatric postnatal day-28 rats were acutely exposed to DFP, and at 3 and 10 months after exposure, they were evaluated using a series of cognitive and behavioral tests with or without the postexposure treatment of GX. Analysis of the neuropathology was performed after 10 months. DFP-exposed animals displayed significant long-term deficits in mood, anxiety, depression, and aggressive traits. In spatial and nonspatial cognitive tests, they displayed striking impairments in learning and memory. Analysis of brain sections showed significant loss of neuronal nuclei antigen(+) principal neurons, parvalbumin(+) inhibitory interneurons, and neurogenesis, along with increased astrogliosis, microglial neuroinflammation, and mossy fiber sprouting. These detrimental neuropathological changes are consistent with behavioral dysfunctions. In the neurosteroid GX-treated cohort, behavioral and cognitive deficits were significantly reduced and were associated with strong protection against long-term neuroinflammation and neurodegeneration. In conclusion, this pediatric model replicates the salient features of children exposed to OPs, and the protective outcomes from neurosteroid intervention support the viability of developing this strategy for mitigating the long-term effects of acute OP exposure in children. SIGNIFICANCE STATEMENT: An estimated 3 million organophosphate exposures occur annually worldwide, with children comprising over 30% of all victims. Our understanding of the neurodevelopmental consequences in children exposed to organophosphates is limited. Here, we investigated the long-term impact of neonatal exposure to diisopropyl-fluorophosphate in pediatric rats. Neurosteroid treatment protected against major deficits in behavior and memory and was well correlated with neuropathological changes. Overall, this pediatric model is helpful to screen novel therapies to mitigate long-term developmental deficits of organophosphate exposure.
Collapse
Affiliation(s)
- Michael James Neff
- Department of Neuroscience and Experimental Therapeutics (M.J.N., D.S.R.) and Institute of Pharmacology and Neurotherapeutics (M.J.N., D.S.R.), School of Medicine, Texas A&M University Health Science Center, Bryan, Texas
| | - Doodipala Samba Reddy
- Department of Neuroscience and Experimental Therapeutics (M.J.N., D.S.R.) and Institute of Pharmacology and Neurotherapeutics (M.J.N., D.S.R.), School of Medicine, Texas A&M University Health Science Center, Bryan, Texas
| |
Collapse
|
5
|
Perucca E, Bialer M, White HS. New GABA-Targeting Therapies for the Treatment of Seizures and Epilepsy: I. Role of GABA as a Modulator of Seizure Activity and Recently Approved Medications Acting on the GABA System. CNS Drugs 2023; 37:755-779. [PMID: 37603262 PMCID: PMC10501955 DOI: 10.1007/s40263-023-01027-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/06/2023] [Indexed: 08/22/2023]
Abstract
γ-Aminobutyric acid (GABA) is the most prevalent inhibitory neurotransmitter in the mammalian brain and has been found to play an important role in the pathogenesis or the expression of many neurological diseases, including epilepsy. Although GABA can act on different receptor subtypes, the component of the GABA system that is most critical to modulation of seizure activity is the GABAA-receptor-chloride (Cl-) channel complex, which controls the movement of Cl- ions across the neuronal membrane. In the mature brain, binding of GABA to GABAA receptors evokes a hyperpolarising (anticonvulsant) response, which is mediated by influx of Cl- into the cell driven by its concentration gradient between extracellular and intracellular fluid. However, in the immature brain and under certain pathological conditions, GABA can exert a paradoxical depolarising (proconvulsant) effect as a result of an efflux of chloride from high intracellular to lower extracellular Cl- levels. Extensive preclinical and clinical evidence indicates that alterations in GABAergic inhibition caused by drugs, toxins, gene defects or other disease states (including seizures themselves) play a causative or contributing role in facilitating or maintaning seizure activity. Conversely, enhancement of GABAergic transmission through pharmacological modulation of the GABA system is a major mechanism by which different antiseizure medications exert their therapeutic effect. In this article, we review the pharmacology and function of the GABA system and its perturbation in seizure disorders, and highlight how improved understanding of this system offers opportunities to develop more efficacious and better tolerated antiseizure medications. We also review the available data for the two most recently approved antiseizure medications that act, at least in part, through GABAergic mechanisms, namely cenobamate and ganaxolone. Differences in the mode of drug discovery, pharmacological profile, pharmacokinetic properties, drug-drug interaction potential, and clinical efficacy and tolerability of these agents are discussed.
Collapse
Affiliation(s)
- Emilio Perucca
- Department of Medicine (Austin Health), The University of Melbourne, Melbourne, VIC, Australia.
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.
- Melbourne Brain Centre, 245 Burgundy Street, Heidelberg, VIC, 3084, Australia.
| | - Meir Bialer
- Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
- David R. Bloom Center for Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - H Steve White
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA, USA
| |
Collapse
|
6
|
Martinez LA, Born HA, Harris S, Regnier-Golanov A, Grieco JC, Weeber EJ, Anderson AE. Quantitative EEG Analysis in Angelman Syndrome: Candidate Method for Assessing Therapeutics. Clin EEG Neurosci 2023; 54:203-212. [PMID: 33203220 DOI: 10.1177/1550059420973095] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The goal of these studies was to use quantitative (q)EEG techniques on data from children with Angelman syndrome (AS) using spectral power analysis, and to evaluate this as a potential biomarker and quantitative method to evaluate therapeutics. Although characteristic patterns are evident in visual inspection, using qEEG techniques has the potential to provide quantitative evidence of treatment efficacy. We first assessed spectral power from baseline EEG recordings collected from children with AS compared to age-matched neurotypical controls, which corroborated the previously reported finding of increased total power driven by elevated delta power in children with AS. We then retrospectively analyzed data collected during a clinical trial evaluating the safety and tolerability of minocycline (3 mg/kg/d) to compare pretreatment recordings from children with AS (4-12 years of age) to EEG activity at the end of treatment and following washout for EEG spectral power and epileptiform events. At baseline and during minocycline treatment, the AS subjects demonstrated increased delta power; however, following washout from minocycline treatment the AS subjects had significantly reduced EEG spectral power and epileptiform activity. Our findings support the use of qEEG analysis in evaluating AS and suggest that this technique may be useful to evaluate therapeutic efficacy in AS. Normalizing EEG power in AS therefore may become an important metric in screening therapeutics to gauge overall efficacy. As therapeutics transition from preclinical to clinical studies, it is vital to establish outcome measures that can quantitatively evaluate putative treatments for AS and neurological disorders with distinctive EEG patterns.
Collapse
Affiliation(s)
- Luis A Martinez
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,The Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.,The Gordon and Mary Cain Pediatric Neurology Research Foundation Laboratories, Texas Children's Hospital, Houston, TX, USA
| | - Heather A Born
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,The Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.,The Gordon and Mary Cain Pediatric Neurology Research Foundation Laboratories, Texas Children's Hospital, Houston, TX, USA
| | - Sarah Harris
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,The Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.,The Gordon and Mary Cain Pediatric Neurology Research Foundation Laboratories, Texas Children's Hospital, Houston, TX, USA
| | - Angelique Regnier-Golanov
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,The Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.,The Gordon and Mary Cain Pediatric Neurology Research Foundation Laboratories, Texas Children's Hospital, Houston, TX, USA
| | - Joseph C Grieco
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Edwin J Weeber
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Anne E Anderson
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,The Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.,The Gordon and Mary Cain Pediatric Neurology Research Foundation Laboratories, Texas Children's Hospital, Houston, TX, USA.,Departments of Neuroscience and Neurology, Baylor College of Medicine, Houston, TX, USA
| |
Collapse
|
7
|
Miller SL, Bennet L, Sutherland AE, Pham Y, McDonald C, Castillo‐Melendez M, Allison BJ, Mihelakis J, Nitsos I, Boyd BJ, Hirst JJ, Walker DW, Hunt RW, Jenkin G, Wong F, Malhotra A, Fahey MC, Yawno T. Ganaxolone versus Phenobarbital for Neonatal Seizure Management. Ann Neurol 2022; 92:1066-1079. [PMID: 36054160 PMCID: PMC9828769 DOI: 10.1002/ana.26493] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 01/12/2023]
Abstract
OBJECTIVE Seizures are more common in the neonatal period than at any other stage of life. Phenobarbital is the first-line treatment for neonatal seizures and is at best effective in approximately 50% of babies, but may contribute to neuronal injury. Here, we assessed the efficacy of phenobarbital versus the synthetic neurosteroid, ganaxolone, to moderate seizure activity and neuropathology in neonatal lambs exposed to perinatal asphyxia. METHODS Asphyxia was induced via umbilical cord occlusion in term lambs at birth. Lambs were treated with ganaxolone (5mg/kg/bolus then 5mg/kg/day for 2 days) or phenobarbital (20mg/kg/bolus then 5mg/kg/day for 2 days) at 6 hours. Abnormal brain activity was classified as stereotypic evolving (SE) seizures, epileptiform discharges (EDs), and epileptiform transients (ETs) using continuous amplitude-integrated electroencephalographic recordings. At 48 hours, lambs were euthanized for brain pathology. RESULTS Asphyxia caused abnormal brain activity, including SE seizures that peaked at 18 to 20 hours, EDs, and ETs, and induced neuronal degeneration and neuroinflammation. Ganaxolone treatment was associated with an 86.4% reduction in the number of seizures compared to the asphyxia group. The total seizure duration in the asphyxia+ganaxolone group was less than the untreated asphyxia group. There was no difference in the number of SE seizures between the asphyxia and asphyxia+phenobarbital groups or duration of SE seizures. Ganaxolone treatment, but not phenobarbital, reduced neuronal degeneration within hippocampal CA1 and CA3 regions, and cortical neurons, and ganaxolone reduced neuroinflammation within the thalamus. INTERPRETATION Ganaxolone provided better seizure control than phenobarbital in this perinatal asphyxia model and was neuroprotective for the newborn brain, affording a new therapeutic opportunity for treatment of neonatal seizures. ANN NEUROL 2022;92:1066-1079.
Collapse
Affiliation(s)
- Suzanne L. Miller
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Laura Bennet
- Department of PhysiologyUniversity of AucklandAucklandNew Zealand
| | - Amy E. Sutherland
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Yen Pham
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Courtney McDonald
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Margie Castillo‐Melendez
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Beth J. Allison
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Jamie Mihelakis
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Ilias Nitsos
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Ben J. Boyd
- Monash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVictoriaAustralia
| | - Jonathan J. Hirst
- School of Biomedical Sciences and Pharmacy, University of NewcastleNewcastleNew South WalesAustralia
| | - David W. Walker
- School of Health and Biomedical Sciences, RMIT UniversityBundooraVictoriaAustralia
| | - Rodney W. Hunt
- Department of PaediatricsMonash UniversityClaytonVictoriaAustralia
| | - Graham Jenkin
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Flora Wong
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia,School of Health and Biomedical Sciences, RMIT UniversityBundooraVictoriaAustralia,Department of PaediatricsMonash UniversityClaytonVictoriaAustralia
| | - Atul Malhotra
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia,Department of PaediatricsMonash UniversityClaytonVictoriaAustralia,Monash Children's HospitalClaytonVictoriaAustralia
| | - Michael C. Fahey
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia,Department of PaediatricsMonash UniversityClaytonVictoriaAustralia,Monash Children's HospitalClaytonVictoriaAustralia
| | - Tamara Yawno
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia,Department of PaediatricsMonash UniversityClaytonVictoriaAustralia
| |
Collapse
|
8
|
Samanta D. Pharmacotherapeutic management of seizures in patients with Angleman syndrome. Expert Opin Pharmacother 2022; 23:1511-1522. [PMID: 35862628 DOI: 10.1080/14656566.2022.2105141] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Approximately 80-90% of patients with Angelman syndrome (AS) develop childhood-onset intractable seizures with major negative impact on the quality of life.Thus adequate management of seizures is the most critical priority to improve health-related quality of life in children with AS. AREAS COVERED The primary focus of the review is on pharmacotherapeutic management of seizures. The first part of the review briefly discusses epileptogenesis and polymorphic seizure phenotypes associated with AS to understand pharmacotherapeutic decision-making better. Next, the review explores individual antiseizure medicines (ASMs) and their potential therapeutic utility. Lastly, some future and emerging treatment options are discussed that can transform the management of seizures in patients with AS. EXPERT OPINION Evidence for treating seizures in AS mainly derives from low-quality studies. Levetiracetam and clobazam are the most commonly used ASMs. Although the potential utility of several other ASMs(valproate, topiramate, lamotrigine, ethosuximide, clonazepam) has been well documented for some time, the treatment landscape may rapidly evolve due to the availability of newer and better tolerated ASMs(cannabidiol oil, brivaracetam, perampanel). In addition, a better understanding of the underlying pathogenesis and the development of molecular therapeutics offer hope for precision therapies for seizures.
Collapse
Affiliation(s)
- Debopam Samanta
- Child Neurology Section, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Dodge A, Morrill N, Weeber EJ, Nash KR. Recovery of Angelman syndrome rat deficits with UBE3A protein supplementation. Mol Cell Neurosci 2022; 120:103724. [DOI: 10.1016/j.mcn.2022.103724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 03/03/2022] [Accepted: 03/23/2022] [Indexed: 11/27/2022] Open
|
11
|
Cosgrove JA, Kelly LK, Kiffmeyer EA, Kloth AD. Sex-dependent influence of postweaning environmental enrichment in Angelman syndrome model mice. Brain Behav 2022; 12:e2468. [PMID: 34985196 PMCID: PMC8865162 DOI: 10.1002/brb3.2468] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 11/09/2021] [Accepted: 12/12/2021] [Indexed: 12/31/2022] Open
Abstract
INTRODUCTION Angelman syndrome (AS) is a rare neurodevelopmental disorder caused by mutation or loss of UBE3A and marked by intellectual disability, ataxia, autism-like symptoms, and other atypical behaviors. One route to treatment may lie in the role that environment plays early in postnatal life. Environmental enrichment (EE) is one manipulation that has shown therapeutic potential in preclinical models of many brain disorders, including neurodevelopmental disorders. Here, we examined whether postweaning EE can rescue behavioral phenotypes in Ube3a maternal deletion mice (AS mice), and whether any improvements are sex-dependent. METHODS Male and female mice (C57BL/6J Ube3atm1Alb mice and wild-type (WT) littermates; ≥10 mice/group) were randomly assigned to standard housing (SH) or EE at weaning. EE had a larger footprint, a running wheel, and a variety of toys that promoted foraging, burrowing, and climbing. Following 6 weeks of EE, animals were submitted to a battery of tests that reliably elicit behavioral deficits in AS mice, including rotarod, open field, marble burying, and forced swim; weights were also monitored. RESULTS In male AS-EE mice, we found complete restoration of motor coordination, marble burying, and forced swim behavior to the level of WT-SH mice. We also observed a complete normalization of exploratory distance traveled in the open field, but we found no rescue of vertical behavior or center time. AS-EE mice also had weights comparable to WT-SH mice. Intriguingly, in the female AS-EE mice, we found a failure of EE to rescue the same behavioral deficits relative to female WT-SH mice. CONCLUSIONS Environmental enrichment is an effective route to correcting the most penetrant phenotypes in male AS mice but not female AS mice. This finding has important implications for the translatability of early behavioral intervention for AS patients, most importantly the potential dependency of treatment response on sex.
Collapse
Affiliation(s)
- Jameson A. Cosgrove
- Department of BiologyAugustana University2001 S. Summit AvenueSioux FallsSouth DakotaUSA
| | - Lauren K. Kelly
- Department of BiologyAugustana University2001 S. Summit AvenueSioux FallsSouth DakotaUSA
| | - Elizabeth A. Kiffmeyer
- Department of BiologyAugustana University2001 S. Summit AvenueSioux FallsSouth DakotaUSA
| | - Alexander D. Kloth
- Department of BiologyAugustana University2001 S. Summit AvenueSioux FallsSouth DakotaUSA
| |
Collapse
|
12
|
Diviccaro S, Cioffi L, Falvo E, Giatti S, Melcangi RC. Allopregnanolone: An overview on its synthesis and effects. J Neuroendocrinol 2022; 34:e12996. [PMID: 34189791 PMCID: PMC9285581 DOI: 10.1111/jne.12996] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 05/20/2021] [Accepted: 05/26/2021] [Indexed: 12/23/2022]
Abstract
Allopregnanolone, a 3α,5α-progesterone metabolite, acts as a potent allosteric modulator of the γ-aminobutyric acid type A receptor. In the present review, the synthesis of this neuroactive steroid occurring in the nervous system is discussed with respect to physiological and pathological conditions. In addition, its physiological and neuroprotective effects are also reported. Interestingly, the levels of this neuroactive steroid, as well as its effects, are sex-dimorphic, suggesting a possible gender medicine based on this neuroactive steroid for neurological disorders. However, allopregnanolone presents low bioavailability and extensive hepatic metabolism, limiting its use as a drug. Therefore, synthetic analogues or a different therapeutic strategy able to increase allopregnanolone levels have been proposed to overcome any pharmacokinetic issues.
Collapse
Affiliation(s)
- Silvia Diviccaro
- Dipartimento di Scienze Farmacologiche e BiomolecolariUniversità degli Studi di MilanoMilanoItaly
| | - Lucia Cioffi
- Dipartimento di Scienze Farmacologiche e BiomolecolariUniversità degli Studi di MilanoMilanoItaly
| | - Eva Falvo
- Dipartimento di Scienze Farmacologiche e BiomolecolariUniversità degli Studi di MilanoMilanoItaly
| | - Silvia Giatti
- Dipartimento di Scienze Farmacologiche e BiomolecolariUniversità degli Studi di MilanoMilanoItaly
| | - Roberto Cosimo Melcangi
- Dipartimento di Scienze Farmacologiche e BiomolecolariUniversità degli Studi di MilanoMilanoItaly
| |
Collapse
|
13
|
The imidazodiazepine, KRM-II-81: An example of a newly emerging generation of GABAkines for neurological and psychiatric disorders. Pharmacol Biochem Behav 2022; 213:173321. [PMID: 35041859 DOI: 10.1016/j.pbb.2021.173321] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 12/21/2021] [Accepted: 12/30/2021] [Indexed: 02/07/2023]
Abstract
GABAkines, or positive allosteric modulators of γ-aminobutyric acid-A (GABAA) receptors, are used for the treatment of anxiety, epilepsy, sleep, and other disorders. The search for improved GABAkines, with reduced safety liabilities (e.g., dependence) or side-effect profiles (e.g., sedation) constituted multiple discovery and development campaigns that involved a multitude of strategies over the past century. Due to the general lack of success in the development of new GABAkines, there had been a decades-long draught in bringing new GABAkines to market. Recently, however, there has been a resurgence of efforts to bring GABAkines to patients, the FDA approval of the neuroactive steroid brexanolone for post-partum depression in 2019 being the first. Other neuroactive steroids are in various stages of clinical development (ganaxolone, zuranolone, LYT-300, Sage-324, PRAX 114, and ETX-155). These GABAkines and non-steroid compounds (GRX-917, a TSPO binding site ligand), darigabat (CVL-865), an α2/3/5-preferring GABAkine, SAN711, an α3-preferring GABAkine, and the α2/3-preferring GABAkine, KRM-II-81, bring new therapeutic promise to this highly utilized medicinal target in neurology and psychiatry. Herein, we also discuss possible conditions that have enabled the transition to a new age of GABAkines. We highlight the pharmacology of KRM-II-81 that has the most preclinical data reported. KRM-II-81 is the lead compound in a new series of orally bioavailable imidazodiazepines entering IND-enabling safety studies. KRM-II-81 has a preclinical profile predicting efficacy against pharmacoresistant epilepsies, traumatic brain injury, and neuropathic pain. KRM-II-81 also produces anxiolytic- and antidepressant-like effects in rodent models. Other key features of the pharmacology of this compound are its low sedation rate, lack of tolerance development, and the ability to prevent the development of seizure sensitization.
Collapse
|
14
|
Excessive Laughter-like Vocalizations, Microcephaly, and Translational Outcomes in the Ube3a Deletion Rat Model of Angelman Syndrome. J Neurosci 2021; 41:8801-8814. [PMID: 34475199 PMCID: PMC8528495 DOI: 10.1523/jneurosci.0925-21.2021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 08/23/2021] [Accepted: 08/26/2021] [Indexed: 02/06/2023] Open
Abstract
Angelman syndrome (AS) is a rare genetic neurodevelopmental disorder characterized by intellectual disabilities, motor and balance deficits, impaired communication, and a happy, excitable demeanor with frequent laughter. We sought to elucidate a preclinical outcome measure in male and female rats that addressed communication abnormalities of AS and other neurodevelopmental disorders in which communication is atypical and/or lack of speech is a core feature. We discovered, and herein report for the first time, excessive laughter-like 50 kHz ultrasonic emissions in the Ube3a mat-/pat+ rat model of AS, which suggests an excitable, playful demeanor and elevated positive affect, similar to the demeanor of individuals with AS. Also in line with the AS phenotype, Ube3a mat-/pat+ rats demonstrated aberrant social interactions with a novel partner, distinctive gait abnormalities, impaired cognition, an underlying LTP deficit, and profound reductions in brain volume. These unique, robust phenotypes provide advantages compared with currently available mouse models and will be highly valuable as outcome measures in the evaluation of therapies for AS.SIGNIFICANCE STATEMENT Angelman syndrome (AS) is a severe neurogenetic disorder for which there is no cure, despite decades of research using mouse models. This study used a recently developed rat model of AS to delineate disease-relevant outcome measures to facilitate therapeutic development. We found the rat to be a strong model of AS, offering several advantages over mouse models by exhibiting numerous AS-relevant phenotypes, including overabundant laughter-like vocalizations, reduced hippocampal LTP, and volumetric anomalies across the brain. These findings are unconfounded by detrimental motor abilities and background strain, issues plaguing mouse models. This rat model represents an important advancement in the field of AS, and the outcome metrics reported herein will be central to the therapeutic pipeline.
Collapse
|
15
|
Elgersma Y, Sonzogni M. UBE3A reinstatement as a disease-modifying therapy for Angelman syndrome. Dev Med Child Neurol 2021; 63:802-807. [PMID: 33543479 PMCID: PMC8248324 DOI: 10.1111/dmcn.14831] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/19/2021] [Indexed: 01/08/2023]
Abstract
Half a century ago, Harry Angelman reported three patients with overlapping clinical features, now well known as Angelman syndrome. Angelman syndrome is caused by mutations affecting the maternally inherited UBE3A gene, which encodes an E3-ubiquitin ligase that is critical for typical postnatal brain development. Emerging evidence indicates that UBE3A plays a particularly important role in the nucleus. However, the critical substrates that are controlled by UBE3A remain elusive, which hinders the search for effective treatments. Moreover, given the multitude of signalling mechanisms that are derailed, it is unlikely that targeting a single pathway is going to be very effective. Therefore, expectations are very high for approaches that aim to restore UBE3A protein levels. A particular promising strategy is an antisense oligonucleotide approach, which activates the silenced paternal UBE3A gene. When successful, such treatments potentially offer a disease-modifying therapy for Angelman syndrome and several other neurodevelopmental disorders. What this paper adds Loss of UBE3A affects multiple signalling pathways in the brain. Emerging evidence suggests that UBE3A plays a critical role in the cell nucleus. Trials using antisense oligonucleotides to restore UBE3A levels are continuing.
Collapse
Affiliation(s)
- Ype Elgersma
- Department of Neuroscience, Erasmus University Medical Center, Rotterdam, the Netherlands
- Deptartment of Clinical Genetics, Erasmus University Medical Center, Rotterdam, the Netherlands
- The ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus MC, Rotterdam, the Netherlands
| | - Monica Sonzogni
- Department of Neuroscience, Erasmus University Medical Center, Rotterdam, the Netherlands
- The ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus MC, Rotterdam, the Netherlands
| |
Collapse
|
16
|
Adhikari A, Copping NA, Beegle J, Cameron DL, Deng P, O'Geen H, Segal DJ, Fink KD, Silverman JL, Anderson JS. Functional rescue in an Angelman syndrome model following treatment with lentivector transduced hematopoietic stem cells. Hum Mol Genet 2021; 30:1067-1083. [PMID: 33856035 PMCID: PMC8188406 DOI: 10.1093/hmg/ddab104] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 12/14/2022] Open
Abstract
Angelman syndrome (AS) is a rare neurodevelopmental disorder characterized by impaired communication skills, ataxia, motor and balance deficits, intellectual disabilities, and seizures. The genetic cause of AS is the neuronal loss of UBE3A expression in the brain. A novel approach, described here, is a stem cell gene therapy which uses lentivector-transduced hematopoietic stem and progenitor cells to deliver functional UBE3A to affected cells. We have demonstrated both the prevention and reversal of AS phenotypes upon transplantation and engraftment of human CD34+ cells transduced with a Ube3a lentivector in a novel immunodeficient Ube3amat−/pat+ IL2rg−/y mouse model of AS. A significant improvement in motor and cognitive behavioral assays as well as normalized delta power measured by electroencephalogram was observed in neonates and adults transplanted with the gene modified cells. Human hematopoietic profiles observed in the lymphoid organs by detection of human immune cells were normal. Expression of UBE3A was detected in the brains of the adult treatment group following immunohistochemical staining illustrating engraftment of the gene-modified cells expressing UBE3A in the brain. As demonstrated with our data, this stem cell gene therapy approach offers a promising treatment strategy for AS, not requiring a critical treatment window.
Collapse
Affiliation(s)
- Anna Adhikari
- Department of Psychiatry and Behavioral Sciences, MIND Institute, University of California Davis School of Medicine, Sacramento, CA 95817, USA
| | - Nycole A Copping
- Department of Psychiatry and Behavioral Sciences, MIND Institute, University of California Davis School of Medicine, Sacramento, CA 95817, USA
| | - Julie Beegle
- Stem Cell Program, Department of Internal Medicine, University of California Davis School of Medicine, Sacramento, CA 95817, USA
| | - David L Cameron
- Stem Cell Program, Department of Neurology, Institute for Regenerative Cures, University of California Davis School of Medicine, Sacramento, CA 95817, USA
| | - Peter Deng
- Stem Cell Program, Department of Neurology, Institute for Regenerative Cures, University of California Davis School of Medicine, Sacramento, CA 95817, USA
| | - Henriette O'Geen
- Department of Biochemistry and Medical Microbiology, UC Davis Genome Center, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - David J Segal
- Department of Biochemistry and Medical Microbiology, UC Davis Genome Center, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Kyle D Fink
- Stem Cell Program, Department of Neurology, Institute for Regenerative Cures, University of California Davis School of Medicine, Sacramento, CA 95817, USA
| | - Jill L Silverman
- Department of Psychiatry and Behavioral Sciences, MIND Institute, University of California Davis School of Medicine, Sacramento, CA 95817, USA
| | - Joseph S Anderson
- Stem Cell Program, Department of Internal Medicine, University of California Davis School of Medicine, Sacramento, CA 95817, USA
| |
Collapse
|
17
|
Egawa K, Nakakubo S, Kimura S, Goto T, Manabe A, Shiraishi H. Flurothyl-induced seizure paradigm revealed higher seizure susceptibility in middle-aged Angelman syndrome mouse model. Brain Dev 2021; 43:515-520. [PMID: 33408038 DOI: 10.1016/j.braindev.2020.12.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/24/2020] [Accepted: 12/17/2020] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Epilepsy is one of the main clinical problems in Angelman syndrome (AS). Seizures typically start in early childhood then decrease or are often alleviated by young adulthood. Several studies using AS model mice showed comparable seizure susceptibility during young adulthood. In contrast, the course of epilepsy post young adulthood differs from persistently relieved to rerising among reports. To elucidate this, we evaluated the seizure susceptibility of AS model mice of two different ages. METHODS Mice lacking maternal Ube3a gene (Ube3am-/p+) of C57BL/6 background or their littermate wild type (WT) were divided into two groups by age, 2 to 3 months (2-3 M) and 6 to 12 months (6-12 M), corresponding to adolescent to young adult aged and middle aged humans, respectively. Seizure susceptibility was evaluated by flurothyl inhalation or intraperitoneal injection of pentylenetetrazole (PTZ IP)-induced acute seizure protocol. RESULTS In the flurothyl-induced seizure paradigm, the latency to seizure occurrence had a significant interaction with genotype and age. Post-hoc analysis revealed that the latency was significantly shorter at 6-12 M than at 2-3 M in Ube3am-/p+ mice, and in Ube3am-/p+ mice than in WT mice at 6-12 M. No significant interaction or difference was observed by PTZ IP. CONCLUSION The flurothyl-induced seizure paradigm revealed that seizure susceptibility of Ube3am-/p+ mice increased with age, similar to clinical studies reporting the reappearance of epilepsy in older age. The flurothyl-induced seizure paradigm applied to middle-aged Ube3am-/p+ mice could be a suitable protocol for screening drugs against seizures in AS.
Collapse
Affiliation(s)
- Kiyoshi Egawa
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan
| | - Sachiko Nakakubo
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan
| | - Shuhei Kimura
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan
| | - Takeru Goto
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan
| | - Atsushi Manabe
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan
| | - Hideaki Shiraishi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan.
| |
Collapse
|
18
|
Lattanzi S, Riva A, Striano P. Ganaxolone treatment for epilepsy patients: from pharmacology to place in therapy. Expert Rev Neurother 2021; 21:1317-1332. [PMID: 33724128 DOI: 10.1080/14737175.2021.1904895] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Introduction: Nonsulfated neurosteroids can provide phasic and tonic inhibition through activation of synaptic and extra-synaptic γ-aminobutyric acid (GABA)A receptors, exhibiting a greater potency for the latter. These actions occur by interacting with modulatory sites that are distinct from those bound by benzodiazepines and barbiturates. Ganaxolone (GNX) is a synthetic analog of the endogenous neurosteroid allopregnanolone and a member of a novel class of neuroactive steroids called epalons.Areas covered: The authors review the pharmacology of GNX, summarize the main clinical evidence about its antiseizure efficacy and tolerability, and suggest implications for clinical practice and future research.Expert opinion: The clinical development of GNX is mainly oriented to target unmet needs and focused on status epilepticus and rare genetic epilepsies that have few or no treatment options.The availability of oral and intravenous formulations allows reaching adult and pediatric patients in acute and chronic care settings. Further evidence will complement the understanding of the potentialities of GNX and possibly lead to indications for use in clinical practice.
Collapse
Affiliation(s)
- Simona Lattanzi
- Neurological Clinic, Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
| | - Antonella Riva
- Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, "G. Gaslini" Institute, University of Genoa, Genova, Italy
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, "G. Gaslini" Institute, University of Genoa, Genova, Italy
| |
Collapse
|
19
|
Copping NA, Silverman JL. Abnormal electrophysiological phenotypes and sleep deficits in a mouse model of Angelman Syndrome. Mol Autism 2021; 12:9. [PMID: 33549123 PMCID: PMC7866697 DOI: 10.1186/s13229-021-00416-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 01/18/2021] [Indexed: 01/17/2023] Open
Abstract
Background Angelman Syndrome (AS) is a rare genetic disorder characterized by impaired communication, motor and balance deficits, intellectual disabilities, recurring seizures and abnormal sleep patterns. The genetic cause of AS is neuronal-specific loss of expression of UBE3A (ubiquitin-protein ligase E6-AP), an imprinted gene. Seizure and sleep disorders are highly prevalent (> 80%) in the AS population. The present experiments were designed to identify translational, neurophysiological outcome measures in a model of AS. Methods We used the exon-2 deletion mouse (Ube3a-del) on a C57BL/6J background to assess seizure, sleep and electrophysiological phenotypes. Seizure susceptibility has been reported in Ube3a-del mice with a variety of seizure induction methods. Here, we provoked seizures by a single high-dose injection of 80 mg/kg pentylenetetrazole. Novel experiments included the utilization of wireless telemetry devices to acquire global electroencephalogram (EEG) and neurophysiological data on electrographic seizures, power spectra, light–dark cycles, sleep stages and sleep spindles in Ube3a-del and WT mice. Results Ube3a-del mice exhibited reduced seizure threshold compared to WT. EEG illustrated that Ube3a-del mice had increased epileptiform spiking activity and delta power, which corroborates findings from other laboratories and recapitulates clinical reports in AS. This is the first report to use a cortical surface-based recording by a wireless telemetry device over tethered/fixed head-mount depth recordings. Less time in both paradoxical and slow-wave sleep, longer latencies to paradoxical sleep stages and total less sleep time in Ube3a-del mice were observed compared to WT. For the first time, we detected fewer sleep spindles in the AS mouse model. Limitations This study was limited to the exon 2 deletion mouse model, and future work will investigate the rat model of AS, containing a complete Ube3a deletion and pair EEG with behavior. Conclusions Our data enhance rigor and translatability as our study provides important corroboration of previous reports on epileptiform and elevated delta power. For the first time we report neurophysiological phenotypes collected via translational methodology. Furthermore, this is the first report of reduced sleep spindles, a critical marker of memory consolidation during sleep, in an AS model. Our results are useful outcomes for therapeutic testing.
Collapse
Affiliation(s)
- N A Copping
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Room 1001B, Research II Building 96, 4625 2nd Avenue, Sacramento, CA, 95817, USA
| | - J L Silverman
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Room 1001B, Research II Building 96, 4625 2nd Avenue, Sacramento, CA, 95817, USA.
| |
Collapse
|
20
|
Samanta D. Epilepsy in Angelman syndrome: A scoping review. Brain Dev 2021; 43:32-44. [PMID: 32893075 PMCID: PMC7688500 DOI: 10.1016/j.braindev.2020.08.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 08/17/2020] [Accepted: 08/17/2020] [Indexed: 12/30/2022]
Abstract
Angelman Syndrome (AS) is characterized by severe developmental delays including marked speech impairment, movement abnormalities(ataxia, tremor), and unique behaviors such as frequent laughter and is caused by dysfunctional maternal UBE3A gene (maternal 15q11-13 deletions, maternal specific UBE3A mutation, uniparental disomy, and imprinting defect). Intractable epileptic seizures since early childhood with characteristic EEG abnormalities are present in 80-90% patients with AS. Underlying pathophysiology may involve neocortical and thalamocortical hyperexcitability secondary to severe reduction of GABAergic input, as well as dysfunctional synaptic plasticity, deficient synaptogenesis, and neuronal morphological immaturity. The onset of epilepsy is most prevalent between 1 and 3 years of age; however, approximately 25% of patients developed epilepsy before one year of age. Various types of generalized seizures are most prevalent, with most common types are myoclonic and atypical absence.More than 95% of epilepsy patients may have daily seizures at least for a limited time during early childhood, and two-third patients develop disabling seizures. Fever provoked seizures, and frequent occurrence of nonconvulsive status epilepticus are two unique features. Seizures are frequently pharmacoresistant. Considering underlying prominent GABAergic dysfunction, clinicians had used AEDs that target GABAergic signaling such as valproate, phenobarbital, and clonazepam as first-line therapies for AS. However, due to the unfavorable side effect profile of these AEDs, a recent treatment approach involves priority use of levetiracetam, clobazam, topiramate, lamotrigine, ethosuximide, VNS, and carbohydrate-restricted diets. Besides symptomatic management, there has been recent progress to find a curative treatment with the following approaches: 1. Gene/protein replacement therapy (Adeno and lentiviral vector therapy to deliver a gene or secretory protein); 2. Activation of the intact but silent paternal copy of UBE3A (antisense oligonucleotide therapy and artificial transcription factors); and 3. Downstream therapies (OV101/gaboxadol, ketone supplement, novel compounds/peptides, anti-inflammatory/regenerative therapy).
Collapse
Affiliation(s)
- Debopam Samanta
- Child Neurology Section, Department of Pediatrics, University of Arkansas for Medical Sciences, Debopam Samanta 1 Children's Way, Little Rock, AR 72202, USA.
| |
Collapse
|
21
|
Cruz E, Descalzi G, Steinmetz A, Scharfman HE, Katzman A, Alberini CM. CIM6P/IGF-2 Receptor Ligands Reverse Deficits in Angelman Syndrome Model Mice. Autism Res 2021; 14:29-45. [PMID: 33108069 PMCID: PMC8579913 DOI: 10.1002/aur.2418] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 09/16/2020] [Accepted: 10/09/2020] [Indexed: 11/12/2022]
Abstract
Angelman syndrome (AS), a genetic disorder that primarily affects the nervous system, is characterized by delayed development, intellectual disability, severe speech impairment, and problems with movement and balance (ataxia). Most affected children also have recurrent seizures (epilepsy). No existing therapies are capable of comprehensively treating the deficits in AS; hence, there is an urgent need to identify new treatments. Here we show that insulin-like growth factor 2 (IGF-2) and mannose-6-phosphate (M6P), ligands of two independent binding sites of the cation-independent M6P/IGF-2 receptor (CIM6P/IGF-2R), reverse most major deficits of AS modeled in mice. Subcutaneous injection of IGF-2 or M6P in mice modeling AS restored cognitive impairments as assessed by measurements of contextual and recognition memories, motor deficits assessed by rotarod and hindlimb clasping, and working memory/flexibility measured by Y-maze. IGF-2 also corrected deficits in marble burying and significantly attenuated acoustically induced seizures. An observational battery of tests confirmed that neither ligand changed basic functions including physical characteristics, general behavioral responses, and sensory reflexes, indicating that they are relatively safe. Our data provide strong preclinical evidence that targeting CIM6P/IGF-2R is a promising approach for developing novel therapeutics for AS. LAY SUMMARY: There is no effective treatment for the neurodevelopmental disorder Angelman syndrome (AS). Using a validated AS mouse model, the Ube3am-/p+ , in this study we show that systemic administration of ligands of the cation independent mannose-6-phosphate receptor, also known as insulin-like growth factor 2 receptor (CIM6P/IGF-2R) reverses cognitive impairment, motor deficits, as well as seizures associated with AS. Thus, ligands that activate the CIM6P/IGF-2R may represent novel, potential therapeutic targets for AS.
Collapse
Affiliation(s)
- Emmanuel Cruz
- Center for Neural Science, New York University, New York, New York, USA
| | - Giannina Descalzi
- Center for Neural Science, New York University, New York, New York, USA
| | - Adam Steinmetz
- Center for Neural Science, New York University, New York, New York, USA
| | - Helen E Scharfman
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, USA
- Department of Neuroscience and Physiology, New York University Langone Health, New York, New York, USA
- Department of Psychiatry, New York University Langone Health, New York, New York, USA
| | - Aaron Katzman
- Center for Neural Science, New York University, New York, New York, USA
| | | |
Collapse
|
22
|
Dutta R, Crawley JN. Behavioral Evaluation of Angelman Syndrome Mice at Older Ages. Neuroscience 2020; 445:163-171. [PMID: 31730795 PMCID: PMC7214203 DOI: 10.1016/j.neuroscience.2019.10.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 10/15/2019] [Accepted: 10/16/2019] [Indexed: 12/20/2022]
Abstract
Angelman syndrome is a neurodevelopmental disorder presenting with severe deficits in motor, speech, and cognitive abilities. The primary genetic cause of Angelman syndrome is a maternally transmitted mutation in the Ube3a gene, which has been successfully modeled in Ube3a mutant mice. Phenotypes have been extensively reported in young adult Ube3a mice. Because symptoms continue throughout life in Angelman syndrome, we tested multiple behavioral phenotypes of male Ube3a mice and WT littermate controls at older adult ages. Social behaviors on both the 3-chambered social approach and male-female social interaction tests showed impairments in Ube3a at 12 months of age. Anxiety-related scores on both the elevated plus-maze and the light ↔ dark transitions assays indicated anxiety-like phenotypes in 12 month old Ube3a mice. Open field locomotion parameters were consistently lower at 12 months. Reduced general exploratory locomotion at this age prevented the interpretation of an anxiety-like phenotype, and likely impacted social tasks. Robust phenotypes in middle-aged Ube3a mice appear to result from continued motor decline. Motor deficits may provide the best outcome measures for preclinical testing of pharmacological targets, towards reductions of symptoms in adults with Angelman syndrome.
Collapse
Affiliation(s)
- Rebecca Dutta
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA 95817, USA
| | - Jacqueline N Crawley
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA 95817, USA.
| |
Collapse
|
23
|
Schultz MN, Crawley JN. Evaluation of a TrkB agonist on spatial and motor learning in the Ube3a mouse model of Angelman syndrome. Learn Mem 2020; 27:346-354. [PMID: 32817301 PMCID: PMC7433657 DOI: 10.1101/lm.051201.119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 02/11/2020] [Indexed: 12/21/2022]
Abstract
Angelman syndrome is a rare neurodevelopmental disorder caused by a mutation in the maternal allele of the gene Ube3a The primary symptoms of Angelman syndrome are severe cognitive deficits, impaired motor functions, and speech disabilities. Analogous phenotypes have been detected in young adult Ube3a mice. Here, we investigate cognitive phenotypes of Ube3a mice as compared to wild-type littermate controls at an older adult age. Water maze spatial learning, swim speed, and rotarod motor coordination and balance were impaired at 6 mo of age, as predicted. Based on previous findings of reduced brain-derived neurotrophic factor in Ube3a mice, a novel therapeutic target, the TrkB agonist 7,8-DHF, was interrogated. Semichronic daily treatment with 7,8-DHF, 5 mg/kg i.p., did not significantly improve the impairments in performance during the acquisition of the water maze hidden platform location in Ube3a mice, after training with either massed or spaced trials, and had no effect on the swim speed and rotarod deficits. Robust behavioral phenotypes in middle-aged Ube3a mice appear to result from continued motor decline. Our results suggest that motor deficits could offer useful outcome measures for preclinical testing of many pharmacological targets, with the goal of reducing symptoms in adults with Angelman syndrome.
Collapse
Affiliation(s)
- Maria N Schultz
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, California 95821, USA
| | - Jacqueline N Crawley
- MIND Institute, Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, California 95821, USA
| |
Collapse
|
24
|
Saravanapandian V, Frohlich J, Hipp JF, Hyde C, Scheffler AW, Golshani P, Cook EH, Reiter LT, Senturk D, Jeste SS. Properties of beta oscillations in Dup15q syndrome. J Neurodev Disord 2020; 12:22. [PMID: 32791992 PMCID: PMC7425173 DOI: 10.1186/s11689-020-09326-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 07/30/2020] [Indexed: 11/21/2022] Open
Abstract
Background Duplications of 15q11.2-q13.1 (Dup15q syndrome) are highly penetrant for autism, intellectual disability, hypotonia, and epilepsy. The 15q region harbors genes critical for brain development, particularly UBE3A and a cluster of gamma-aminobutyric acid type A receptor (GABAAR) genes. We recently described an electrophysiological biomarker of the syndrome, characterized by excessive beta oscillations (12–30 Hz), resembling electroencephalogram (EEG) changes induced by allosteric modulation of GABAARs. In this follow-up study, we tested a larger cohort of children with Dup15q syndrome to comprehensively examine properties of this EEG biomarker that would inform its use in future clinical trials, specifically, its (1) relation to basic clinical features, such as age, duplication type, and epilepsy; (2) relation to behavioral characteristics, such as cognition and adaptive function; (3) stability over time; and (4) reproducibility of the signal in clinical EEG recordings. Methods We computed EEG power and beta peak frequency (BPF) in a cohort of children with Dup15q syndrome (N = 41, age range 9–189 months). To relate EEG parameters to clinical (study 1) and behavioral features (study 2), we examined age, duplication type, epilepsy, cognition, and daily living skills (DLS) as predictors of beta power and BPF. To evaluate stability over time (study 3), we derived the intraclass correlation coefficients (ICC) from beta power and BPF computed from children with multiple EEG recordings (N = 10, age range 18–161 months). To evaluate reproducibility in a clinical setting (study 4), we derived ICCs from beta power computed from children (N = 8, age range 19–96 months), who had undergone both research EEG and clinical EEG. Results The most promising relationships between EEG and clinical traits were found using BPF. BPF was predicted both by epilepsy status (R2 = 0.11, p = 0.038) and the DLS component of the Vineland Adaptive Behavior Scale (R2 = 0.17, p = 0.01). Beta power and peak frequency showed high stability across repeated visits (beta power ICC = 0.93, BPF ICC = 0.92). A reproducibility analysis revealed that beta power estimates are comparable between research and clinical EEG (ICC = 0.94). Conclusions In this era of precision health, with pharmacological and neuromodulatory therapies being developed and tested for specific genetic etiologies of neurodevelopmental disorders, quantification and examination of mechanistic biomarkers can greatly improve clinical trials. To this end, the robust beta oscillations evident in Dup15q syndrome are clinically reproducible and stable over time. With future preclinical and computational studies that will help disentangle the underlying mechanism, it is possible that this biomarker could serve as a robust measure of drug target engagement or a proximal outcome measure in future disease modifying intervention trials.
Collapse
Affiliation(s)
- Vidya Saravanapandian
- Center for Autism Research and Treatment, Semel Institute for Neuroscience, University of California Los Angeles, Los Angeles, CA, 90024, USA.
| | - Joel Frohlich
- Center for Autism Research and Treatment, Semel Institute for Neuroscience, University of California Los Angeles, Los Angeles, CA, 90024, USA.,Roche Pharma Research and Early Development, Neuroscience, Ophthalmology and Rare Diseases, Roche Innovation Center Basel, Basel, Switzerland.,Department of Psychology, University of California Los Angeles, 3423 Franz Hall, Los Angeles, CA, 90095, USA
| | - Joerg F Hipp
- Roche Pharma Research and Early Development, Neuroscience, Ophthalmology and Rare Diseases, Roche Innovation Center Basel, Basel, Switzerland
| | - Carly Hyde
- Center for Autism Research and Treatment, Semel Institute for Neuroscience, University of California Los Angeles, Los Angeles, CA, 90024, USA
| | - Aaron W Scheffler
- Department of Biostatistics, University of California Los Angeles School of Public Health, Room 21-254C CHS, Los Angeles, CA, 90095, USA
| | - Peyman Golshani
- Department of Neurology and Semel Institute for Neuroscience, David Geffen School of Medicine, 710 Westwood Plaza, Los Angeles, CA, 90095, USA.,West Los Angeles VA Medical Center, 11301 Wilshire Blvd, Los Angeles, CA, 90073, USA
| | - Edwin H Cook
- Department of Psychiatry, University of Illinois at Chicago, 1747 W Roosevelt Road, Chicago, IL, 60608, USA
| | - Lawrence T Reiter
- Department of Neurology, Pediatrics and Anatomy & Neurobiology, The University of Tennessee Health Science Center, 855 Monroe Ave., Link, Memphis, TN, 415, USA
| | - Damla Senturk
- Department of Biostatistics, University of California Los Angeles School of Public Health, Room 21-254C CHS, Los Angeles, CA, 90095, USA
| | - Shafali S Jeste
- Center for Autism Research and Treatment, Semel Institute for Neuroscience, University of California Los Angeles, Los Angeles, CA, 90024, USA
| |
Collapse
|
25
|
Yang X. Characterizing spine issues: If offers novel therapeutics to Angelman syndrome. Dev Neurobiol 2020; 80:200-209. [PMID: 32378784 DOI: 10.1002/dneu.22757] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 05/01/2020] [Indexed: 12/28/2022]
Abstract
Angelman syndrome (AS) is a rare neurodevelopmental disorder characterized by severe mental retardation, microcephaly, speech impairment, frequent epilepsy, EEG abnormalities, ataxic movements, tongue protrusion, bursts of laughter, sleep abruptions, and hyperactivity. AS results from loss of function of the imprinted UBE3A (ubiquitin-protein ligase E3A) gene on chromosome 15q11-q13, including a mutation on the maternal allele of Ube3a, a large deletion of the maternally inherited chromosomal region 15q11-13, paternal uniparental disomy of chromosome 15q11-13, or an imprinting defect. The Ube3a maternal deleted mouse model recaptured the major phenotypes of AS patients include seizure, learning and memory impairments, sleep disturbance, and motor problems. Owing to the activity-dependent structural and functional plasticity, dendritic spines are believed as the basic subcellular compartment for learning and memory and the sites where LTP and LTD are induced. Defects of spine formation and dynamics are common among several neurodevelopmental disorders and neuropsychiatric disorders including AS and reflect the underlying synaptopathology, which drives clinically relevant behavioral deficits. This review will summarize the impaired spine density, morphology, and synaptic plasticity in AS and propose that future explorations on spine dynamics and synaptic plasticity may help develop novel interventions and therapy for neurodevelopmental disorders like AS.
Collapse
Affiliation(s)
- Xin Yang
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China
| |
Collapse
|
26
|
Giatti S, Diviccaro S, Falvo E, Garcia-Segura LM, Melcangi RC. Physiopathological role of the enzymatic complex 5α-reductase and 3α/β-hydroxysteroid oxidoreductase in the generation of progesterone and testosterone neuroactive metabolites. Front Neuroendocrinol 2020; 57:100836. [PMID: 32217094 DOI: 10.1016/j.yfrne.2020.100836] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/04/2020] [Accepted: 03/18/2020] [Indexed: 12/22/2022]
Abstract
The enzymatic complex 5α-reductase (5α-R) and 3α/3β-hydroxysteroid oxidoreductase (HSOR) is expressed in the nervous system, where it transforms progesterone (PROG) and testosterone (T) into neuroactive metabolites. These metabolites regulate myelination, brain maturation, neurotransmission, reproductive behavior and the stress response. The expression of 5α-R and 3α-HSOR and the levels of PROG and T reduced metabolites show regional and sex differences in the nervous system and are affected by changing physiological conditions as well as by neurodegenerative and psychiatric disorders. A decrease in their nervous tissue levels may negatively impact the course and outcome of some pathological events. However, in other pathological conditions their increased levels may have a negative impact. Thus, the use of synthetic analogues of these steroids or 5α-R modulation have been proposed as therapeutic approaches for several nervous system pathologies. However, further research is needed to fully understand the consequences of these manipulations, in particular with 5α-R inhibitors.
Collapse
Affiliation(s)
- Silvia Giatti
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Silvia Diviccaro
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Eva Falvo
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Luis Miguel Garcia-Segura
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain; Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - Roberto Cosimo Melcangi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy.
| |
Collapse
|
27
|
Yang X. Towards an understanding of Angelman syndrome in mice studies. J Neurosci Res 2019; 98:1162-1173. [PMID: 31867793 DOI: 10.1002/jnr.24576] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 11/28/2019] [Accepted: 12/04/2019] [Indexed: 12/13/2022]
Abstract
Angelman syndrome (AS) is a rare neurodevelopmental disorder characterized by severe mental retardation, absence of speech, abnormal motor coordination, abnormal EEG, and spontaneous seizure. AS is caused by a deficiency in the ubiquitin ligase E3A (Ube3a) gene product, known to play a dual role as both ubiquitin ligase and transcription coactivator. In AS animal models, multiple Ube3a substrates are accumulated in neurons. So far, studies in mouse models have either aimed at re-expressing Ube3a or manipulating downstream signaling pathways. Reintroducing Ube3a in AS mice showed promising results but may have two caveats. First, it may cause an overdosage in the Ube3a expression, which in turn is known to contribute to autism spectrum disorders. Second, in mutation cases, the exogenous Ube3a may have to compete with the mutated endogenous form. Such two caveats left spaces for developing therapies or interventions directed to targets downstream Ube3a. Notably, Ube3a expression is dynamically regulated by neuronal activity and plays a crucial role in synaptic plasticity. The abnormal synaptic plasticity uncovered in AS mice has been frequently rescued, but circuits symptoms like seizure are resistant to treatment. Future investigations are needed to further clarify the function (s) of Ube3a during development. Here I reviewed the recently identified major Ube3a substrates and signaling pathways involved in AS pathology, the Ube3a expression, imprinting and evolution, the AS mouse models that have been generated and inspired therapeutic potentials, and finally proposed some future explorations to better understand the AS pathology.
Collapse
Affiliation(s)
- Xin Yang
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China
| |
Collapse
|
28
|
Shaw JC, Berry MJ, Dyson RM, Crombie GK, Hirst JJ, Palliser HK. Reduced Neurosteroid Exposure Following Preterm Birth and Its' Contribution to Neurological Impairment: A Novel Avenue for Preventative Therapies. Front Physiol 2019; 10:599. [PMID: 31156466 PMCID: PMC6529563 DOI: 10.3389/fphys.2019.00599] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 04/26/2019] [Indexed: 12/21/2022] Open
Abstract
Children born preterm are at an increased risk of developing cognitive problems and neuro-behavioral disorders such as attention deficit hyperactivity disorder (ADHD) and anxiety. Whilst neonates born at all gestational ages, even at term, can experience poor cognitive outcomes due to birth-complications such as birth asphyxia, it is becoming widely known that children born preterm in particular are at significant risk for learning difficulties with an increased utilization of special education resources, when compared to their healthy term-born peers. Additionally, those born preterm have evidence of altered cerebral myelination with reductions in white matter volumes of the frontal cortex, hippocampus and cerebellum evident on magnetic resonance imaging (MRI). This disruption to myelination may underlie some of the pathophysiology of preterm-associated brain injury. Compared to a fetus of the same post-conceptional age, the preterm newborn loses access to in utero factors that support and promote healthy brain development. Furthermore, the preterm ex utero environment is hostile to the developing brain with a myriad of environmental, biochemical and excitotoxic stressors. Allopregnanolone is a key neuroprotective fetal neurosteroid which has promyelinating effects in the developing brain. Preterm birth leads to an abrupt loss of the protective effects of allopregnanolone, with a dramatic drop in allopregnanolone concentrations in the preterm neonatal brain compared to the fetal brain. This occurs in conjunction with reduced myelination of the hippocampus, subcortical white matter and cerebellum; thus, damage to neurons, astrocytes and especially oligodendrocytes of the developing nervous system can occur in the vulnerable developmental window prior to term as a consequence reduced allopregnanolone. In an effort to prevent preterm-associated brain injury a number of therapies have been considered, but to date, other than antenatal magnesium sulfate and corticosteroid therapy, none have become part of standard clinical care for vulnerable infants. Therefore, there remains an urgent need for improved therapeutic options to prevent brain injury in preterm neonates. The actions of the placentally derived neurosteroid allopregnanolone on GABAA receptor signaling has a major role in late gestation neurodevelopment. The early loss of this intrauterine neurotrophic support following preterm birth may be pivotal to development of neurodevelopmental morbidity. Thus, restoring the in utero neurosteroid environment for preterm neonates may represent a new and clinically feasible treatment option for promoting better trajectories of myelination and brain development, and therefore reducing neurodevelopmental disorders in children born preterm.
Collapse
Affiliation(s)
- Julia C. Shaw
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, NSW, Australia
- Mothers and Babies Research Centre, Hunter Medical Research Institute, University of Newcastle, Newcastle, NSW, Australia
| | - Mary J. Berry
- Department of Paediatrics and Child Health, University of Otago, Wellington, Wellington, New Zealand
- Centre for Translational Physiology, University of Otago, Wellington, Wellington, New Zealand
| | - Rebecca M. Dyson
- Department of Paediatrics and Child Health, University of Otago, Wellington, Wellington, New Zealand
- Centre for Translational Physiology, University of Otago, Wellington, Wellington, New Zealand
| | - Gabrielle K. Crombie
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, NSW, Australia
- Mothers and Babies Research Centre, Hunter Medical Research Institute, University of Newcastle, Newcastle, NSW, Australia
| | - Jonathan J. Hirst
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, NSW, Australia
- Mothers and Babies Research Centre, Hunter Medical Research Institute, University of Newcastle, Newcastle, NSW, Australia
| | - Hannah K. Palliser
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, NSW, Australia
- Mothers and Babies Research Centre, Hunter Medical Research Institute, University of Newcastle, Newcastle, NSW, Australia
| |
Collapse
|
29
|
Ratner MH, Kumaresan V, Farb DH. Neurosteroid Actions in Memory and Neurologic/Neuropsychiatric Disorders. Front Endocrinol (Lausanne) 2019; 10:169. [PMID: 31024441 PMCID: PMC6465949 DOI: 10.3389/fendo.2019.00169] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 02/28/2019] [Indexed: 12/24/2022] Open
Abstract
Memory dysfunction is a symptomatic feature of many neurologic and neuropsychiatric disorders; however, the basic underlying mechanisms of memory and altered states of circuitry function associated with disorders of memory remain a vast unexplored territory. The initial discovery of endogenous neurosteroids triggered a quest to elucidate their role as neuromodulators in normal and diseased brain function. In this review, based on the perspective of our own research, the advances leading to the discovery of positive and negative neurosteroid allosteric modulators of GABA type-A (GABAA), NMDA, and non-NMDA type glutamate receptors are brought together in a historical and conceptual framework. We extend the analysis toward a state-of-the art view of how neurosteroid modulation of neural circuitry function may affect memory and memory deficits. By aggregating the results from multiple laboratories using both animal models for disease and human clinical research on neuropsychiatric and age-related neurodegenerative disorders, elements of a circuitry level view begins to emerge. Lastly, the effects of both endogenously active and exogenously administered neurosteroids on neural networks across the life span of women and men point to a possible underlying pharmacological connectome by which these neuromodulators might act to modulate memory across diverse altered states of mind.
Collapse
|
30
|
Copping NA, Christian SGB, Ritter DJ, Islam MS, Buscher N, Zolkowska D, Pride MC, Berg EL, LaSalle JM, Ellegood J, Lerch JP, Reiter LT, Silverman JL, Dindot SV. Neuronal overexpression of Ube3a isoform 2 causes behavioral impairments and neuroanatomical pathology relevant to 15q11.2-q13.3 duplication syndrome. Hum Mol Genet 2017; 26:3995-4010. [PMID: 29016856 PMCID: PMC5886211 DOI: 10.1093/hmg/ddx289] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 06/21/2017] [Accepted: 07/10/2017] [Indexed: 01/07/2023] Open
Abstract
Maternally derived copy number gains of human chromosome 15q11.2-q13.3 (Dup15q syndrome or Dup15q) cause intellectual disability, epilepsy, developmental delay, hypotonia, speech impairments, and minor dysmorphic features. Dup15q syndrome is one of the most common and penetrant chromosomal abnormalities observed in individuals with autism spectrum disorder (ASD). Although ∼40 genes are located in the 15q11.2-q13.3 region, overexpression of the ubiquitin-protein E3A ligase (UBE3A) gene is thought to be the predominant molecular cause of the phenotypes observed in Dup15q syndrome. The UBE3A gene demonstrates maternal-specific expression in neurons and loss of maternal UBE3A causes Angelman syndrome, a neurodevelopmental disorder with some overlapping neurological features to Dup15q. To directly test the hypothesis that overexpression of UBE3A is an important underlying molecular cause of neurodevelopmental dysfunction, we developed and characterized a mouse overexpressing Ube3a isoform 2 in excitatory neurons. Ube3a isoform 2 is conserved between mouse and human and known to play key roles in neuronal function. Transgenic mice overexpressing Ube3a isoform 2 in excitatory forebrain neurons exhibited increased anxiety-like behaviors, learning impairments, and reduced seizure thresholds. However, these transgenic mice displayed normal social approach, social interactions, and repetitive motor stereotypies that are relevant to ASD. Reduced forebrain, hippocampus, striatum, amygdala, and cortical volume were also observed. Altogether, these findings show neuronal overexpression of Ube3a isoform 2 causes phenotypes translatable to neurodevelopmental disorders.
Collapse
Affiliation(s)
- Nycole A Copping
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | | | - Dylan J Ritter
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
- Texas A&M, College Station, TX, USA
| | - M Saharul Islam
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Nathalie Buscher
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Dorota Zolkowska
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Michael C Pride
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Elizabeth L Berg
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Janine M LaSalle
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Jacob Ellegood
- The Hospital for Sick Children, Mouse Imaging Centre, Toronto, ON, Canada
| | - Jason P Lerch
- The Hospital for Sick Children, Mouse Imaging Centre, Toronto, ON, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Lawrence T Reiter
- Departments of Neurology, Pediatrics and Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jill L Silverman
- MIND Institute, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | | |
Collapse
|
31
|
Shaw JC, Palliser HK, Dyson RM, Berry MJ, Hirst JJ. Disruptions to the cerebellar GABAergic system in juvenile guinea pigs following preterm birth. Int J Dev Neurosci 2017; 65:1-10. [PMID: 29024720 DOI: 10.1016/j.ijdevneu.2017.10.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 10/05/2017] [Accepted: 10/06/2017] [Indexed: 10/18/2022] Open
Abstract
BACKGROUND Children that are born preterm are at an increased risk of developing cognitive problems and behavioural disorders, such as attention deficit hyperactivity disorder (ADHD). There is increasing interest in the role of the cerebellum in these processes and the potential involvement of GABAergic pathways in neurodevelopmental disorders. We propose that preterm birth, and the associated loss of the trophic intrauterine environment, alters the development of the cerebellum, contributing to ongoing neurobehavioral disorders. METHODS Guinea pigs were delivered preterm (GA62) or spontaneously at term (GA69), and tissues collected at corrected postnatal day (PND) 28. Neurodevelopmental and GABAergic markers myelin basic protein (MBP), neuronal nuclei (NeuN), calbindin (Purkinje cells), and GAD67 (GABA synthesis enzyme) were analysed in cerebellar lobules IX and X by immunohistochemistry. Protein expression of GAD67 and GAT1 (GABA transporter enzyme) were quantified by western blot, whilst neurosteroid-sensitive GABAA receptor subunits were measured by RT-PCR. RESULTS MBP immunostaining was increased in lobule IX of preterm males, and reduced in lobule X of preterm females when compared to their term counterparts. GAD67 staining was decreased in lobule IX and X of the preterm males, but only in lobule X of the preterm females compared to term cohorts for each sex. Internal granule cell layer width of lobule X was decreased in preterm cohorts of both sexes compared to terms. There were no differences between gestational age groups for NeuN staining, GAD67 and GAT1 protein expression as measured by western blotting, or GABAA receptor subunits as measured by RT-PCR between preterm and term for either sex. CONCLUSIONS The present findings suggest that components of the cerebellar GABAergic system of the ex-preterm cerebellum are disrupted. The higher expression of myelin in the preterm males may be due to a deficit in axonal pruning, whereas females have a deficit in myelination at 28 corrected days of age. Together these ongoing alterations may contribute to the neurodevelopmental and behavioural disorders observed in those born preterm.
Collapse
Affiliation(s)
- Julia C Shaw
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, Australia; Mothers and Babies Research Centre, Hunter Medical Research Institute, Australia.
| | - Hannah K Palliser
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, Australia; Mothers and Babies Research Centre, Hunter Medical Research Institute, Australia
| | - Rebecca M Dyson
- Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand; Centre for Translational Physiology, University of Otago, Wellington, New Zealand
| | - Mary J Berry
- Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand; Centre for Translational Physiology, University of Otago, Wellington, New Zealand
| | - Jonathan J Hirst
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, Australia; Mothers and Babies Research Centre, Hunter Medical Research Institute, Australia
| |
Collapse
|