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Glinton KE, Gijavanekar C, Rajagopal A, Mackay LP, Martin KA, Pearl PL, Gibson KM, Wilson TA, Sutton VR, Elsea SH. Succinic semialdehyde dehydrogenase deficiency: a metabolic and genomic approach to diagnosis. Front Genet 2024; 15:1405468. [PMID: 39011401 PMCID: PMC11247174 DOI: 10.3389/fgene.2024.1405468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 05/02/2024] [Indexed: 07/17/2024] Open
Abstract
Genomic sequencing offers an untargeted, data-driven approach to genetic diagnosis; however, variants of uncertain significance often hinder the diagnostic process. The discovery of rare genomic variants without previously known functional evidence of pathogenicity often results in variants being overlooked as potentially causative, particularly in individuals with undifferentiated phenotypes. Consequently, many neurometabolic conditions, including those in the GABA (gamma-aminobutyric acid) catabolism pathway, are underdiagnosed. Succinic semialdehyde dehydrogenase deficiency (SSADHD, OMIM #271980) is a neurometabolic disorder in the GABA catabolism pathway. The disorder is due to bi-allelic pathogenic variants in ALDH5A1 and is usually characterized by moderate-to-severe developmental delays, hypotonia, intellectual disability, ataxia, seizures, hyperkinetic behavior, aggression, psychiatric disorders, and sleep disturbances. In this study, we utilized an integrated approach to diagnosis of SSADHD by examining molecular, clinical, and metabolomic data from a single large commercial laboratory. Our analysis led to the identification of 16 patients with likely SSADHD along with three novel variants. We also showed that patients with this disorder have a clear metabolomic signature that, along with molecular and clinical findings, may allow for more rapid and efficient diagnosis. We further surveyed all available pathogenic/likely pathogenic variants and used this information to estimate the global prevalence of this disease. Taken together, our comprehensive analysis allows for a global approach to the diagnosis of SSADHD and provides a pathway to improved diagnosis and potential incorporation into newborn screening programs. Furthermore, early diagnosis facilitates referral to genetic counseling, family support, and access to targeted treatments-taken together, these provide the best outcomes for individuals living with either GABA-TD or SSADHD, as well as other rare conditions.
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Affiliation(s)
- Kevin E. Glinton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Charul Gijavanekar
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Abbhirami Rajagopal
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Laura P. Mackay
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Kirt A. Martin
- NeoGenomics Laboratories, Aliso Viejo, CA, United States
| | - Phillip L. Pearl
- Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States
| | - K. Michael Gibson
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, United States
| | - Theresa A. Wilson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - V. Reid Sutton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Baylor Genetics Laboratories, Houston, TX, United States
| | - Sarah H. Elsea
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Baylor Genetics Laboratories, Houston, TX, United States
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Tokatly Latzer I, Bertoldi M, Blau N, DiBacco ML, Elsea SH, García-Cazorla À, Gibson KM, Gropman AL, Hanson E, Hoffman C, Jeltsch K, Juliá-Palacios N, Knerr I, Lee HHC, Malaspina P, McConnell A, Opladen T, Oppebøen M, Rotenberg A, Walterfang M, Wang-Tso L, Wevers RA, Roullet JB, Pearl PL. Consensus guidelines for the diagnosis and management of succinic semialdehyde dehydrogenase deficiency. Mol Genet Metab 2024; 142:108363. [PMID: 38452608 PMCID: PMC11073920 DOI: 10.1016/j.ymgme.2024.108363] [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: 11/17/2023] [Revised: 02/27/2024] [Accepted: 02/29/2024] [Indexed: 03/09/2024]
Abstract
Succinic semialdehyde dehydrogenase deficiency (SSADHD) (OMIM #271980) is a rare autosomal recessive metabolic disorder caused by pathogenic variants of ALDH5A1. Deficiency of SSADH results in accumulation of γ-aminobutyric acid (GABA) and other GABA-related metabolites. The clinical phenotype of SSADHD includes a broad spectrum of non-pathognomonic symptoms such as cognitive disabilities, communication and language deficits, movement disorders, epilepsy, sleep disturbances, attention problems, anxiety, and obsessive-compulsive traits. Current treatment options for SSADHD remain supportive, but there are ongoing attempts to develop targeted genetic therapies. This study aimed to create consensus guidelines for the diagnosis and management of SSADHD. Thirty relevant statements were initially addressed by a systematic literature review, resulting in different evidence levels of strength according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria. The highest level of evidence (level A), based on randomized controlled trials, was unavailable for any of the statements. Based on cohort studies, Level B evidence was available for 12 (40%) of the statements. Thereupon, through a process following the Delphi Method and directed by the Appraisal of Guidelines for Research and Evaluation (AGREE II) criteria, expert opinion was sought, and members of an SSADHD Consensus Group evaluated all the statements. The group consisted of neurologists, epileptologists, neuropsychologists, neurophysiologists, metabolic disease specialists, clinical and biochemical geneticists, and laboratory scientists affiliated with 19 institutions from 11 countries who have clinical experience with SSADHD patients and have studied the disorder. Representatives from parent groups were also included in the Consensus Group. An analysis of the survey's results yielded 25 (83%) strong and 5 (17%) weak agreement strengths. These first-of-their-kind consensus guidelines intend to consolidate and unify the optimal care that can be provided to individuals with SSADHD.
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Affiliation(s)
- Itay Tokatly Latzer
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; School of Medicine, Faculty of Medicine and Health Sciences, Tel-Aviv University, Tel Aviv, Israel.
| | - Mariarita Bertoldi
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Italy.
| | - Nenad Blau
- Division of Metabolism, University Children's Hospital, Zürich, Switzerland; Children's Research Center, University Children's Hospital Zurich, Switzerland.
| | - Melissa L DiBacco
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Sarah H Elsea
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Àngels García-Cazorla
- Neurometabolic Unit, Neurology Department, Institut de Recerca, Hospital Sant Joan de Déu, Barcelona, Spain.
| | - K Michael Gibson
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, USA.
| | - Andrea L Gropman
- Division of Neurogenetics and Neurodevelopmental Disabilities, Children's National Hospital, Washington, D.C, USA.
| | - Ellen Hanson
- Human Neurobehavioral Core, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, MA 02115, USA.
| | | | - Kathrin Jeltsch
- Heidelberg University, Medical Faculty Heidelberg, Center for Pediatric and Adolescent Medicine, Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg, Germany.
| | - Natalia Juliá-Palacios
- Neurometabolic Unit, Neurology Department, Institut de Recerca, Hospital Sant Joan de Déu, Barcelona, Spain.
| | - Ina Knerr
- National Centre for Inherited Metabolic Disorders, Children's Health Ireland, Temple Street, Dublin, Ireland.
| | - Henry H C Lee
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA.
| | - Patrizia Malaspina
- Department of Biology, Tor Vergata University, Via della Ricerca Scientifica s.n.c., Rome 00133, Italy.
| | | | - Thomas Opladen
- Heidelberg University, Medical Faculty Heidelberg, Center for Pediatric and Adolescent Medicine, Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg, Germany.
| | | | - Alexander Rotenberg
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA.
| | - Mark Walterfang
- Neuropsychiatry, Royal Melbourne Hospital, Melbourne, Australia; Department of Psychiatry, University of Melbourne, Melbourne, Australia; Florey Institute of Neuroscience and Mental Health, Melbourne, Australia; Department of Health and Medical Sciences, Edith Cowan University, Perth, Australia.
| | - Lee Wang-Tso
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan
| | - Ron A Wevers
- Translational Metabolic Laboratory, Department Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands.
| | - Jean-Baptiste Roullet
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, USA.
| | - Phillip L Pearl
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
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Lee HHC, McGinty GE, Pearl PL, Rotenberg A. Understanding the Molecular Mechanisms of Succinic Semialdehyde Dehydrogenase Deficiency (SSADHD): Towards the Development of SSADH-Targeted Medicine. Int J Mol Sci 2022; 23:2606. [PMID: 35269750 PMCID: PMC8910003 DOI: 10.3390/ijms23052606] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 11/21/2022] Open
Abstract
Succinic semialdehyde dehydrogenase deficiency (SSADHD) is a rare genetic disorder caused by inefficient metabolic breakdown of the major inhibitory neurotransmitter, γ-aminobutyric acid (GABA). Pathologic brain accumulation of GABA and γ-hydroxybutyrate (GHB), a neuroactive by-product of GABA catabolism, leads to a multitude of molecular abnormalities beginning in early life, culminating in multifaceted clinical presentations including delayed psychomotor development, intellectual disability, hypotonia, and ataxia. Paradoxically, over half of patients with SSADHD also develop epilepsy and face a significant risk of sudden unexpected death in epilepsy (SUDEP). Here, we review some of the relevant molecular mechanisms through which impaired synaptic inhibition, astrocytic malfunctions and myelin defects might contribute to the complex SSADHD phenotype. We also discuss the gaps in knowledge that need to be addressed for the implementation of successful gene and enzyme replacement SSADHD therapies. We conclude with a description of a novel SSADHD mouse model that enables 'on-demand' SSADH restoration, allowing proof-of-concept studies to fine-tune SSADH restoration in preparation for eventual human trials.
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Affiliation(s)
- Henry H. C. Lee
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA 02115, USA; (G.E.M.); (A.R.)
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Gabrielle E. McGinty
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA 02115, USA; (G.E.M.); (A.R.)
| | - Phillip L. Pearl
- Division of Epilepsy & Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Boston, MA 02115, USA;
| | - Alexander Rotenberg
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA 02115, USA; (G.E.M.); (A.R.)
- Division of Epilepsy & Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Boston, MA 02115, USA;
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Tsuboyama M, Liu J, Kaye H, DiBacco M, Pearl PL, Rotenberg A. Transcranial Magnetic Stimulation in Succinic Semialdehyde Dehydrogenase Deficiency: A Measure of Maturational Trajectory of Cortical Excitability. J Child Neurol 2021; 36:1169-1176. [PMID: 34058900 PMCID: PMC8630082 DOI: 10.1177/08830738211008735] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Succinic semialdehyde dehydrogenase deficiency (SSADHD) is a disorder of GABA degradation with use-dependent downregulation of postsynaptic GABAA/B receptors. We aim to measure the resulting cortical excitation: inhibition ratio using transcranial magnetic stimulation. METHODS In this single-center observational study, 18 subjects with SSADHD and 8 healthy controls underwent transcranial magnetic stimulation. Resting motor threshold, cortical silent period, and long-interval intracortical inhibition were measured in both groups. Resting motor threshold in focal epilepsy patients from an institutional transcranial magnetic stimulation database were also included. RESULTS SSADHD subjects had higher resting motor threshold than healthy controls but lower relative to focal epilepsy patients. Resting motor threshold decreased with age in all groups. Cortical silent period was longer in SSADHD subjects than in healthy controls. No difference was detected in long-interval intracortical inhibition between the 2 groups. CONCLUSION Findings suggest abnormal corticospinal tract physiology in SSADHD, but with preserved developmental trajectory for corticospinal tract maturation. Defining features of these transcranial magnetic stimulation metrics in SSADHD will be better elucidated through this ongoing longitudinal study.
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Affiliation(s)
- Melissa Tsuboyama
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, 1862Boston Children's Hospital, Boston, MA, USA
| | - Jingjing Liu
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, 1862Boston Children's Hospital, Boston, MA, USA.,F.M. Kirby Neurobiology Center, 1862Boston Children's Hospital, Boston, MA, USA
| | - Harper Kaye
- 12259Boston University School of Medicine, Behavioral Neuroscience Program, Boston, MA, USA
| | - Melissa DiBacco
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, 1862Boston Children's Hospital, Boston, MA, USA
| | - Phillip L Pearl
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, 1862Boston Children's Hospital, Boston, MA, USA
| | - Alexander Rotenberg
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, 1862Boston Children's Hospital, Boston, MA, USA.,F.M. Kirby Neurobiology Center, 1862Boston Children's Hospital, Boston, MA, USA.,Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA, USA
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Schreiber JM, Wiggs E, Cuento R, Norato G, Dustin IH, Rolinski R, Austermuehle A, Zhou X, Inati SK, Gibson KM, Pearl PL, Theodore WH. A Randomized Controlled Trial of SGS-742, a γ-aminobutyric acid B (GABA-B) Receptor Antagonist, for Succinic Semialdehyde Dehydrogenase Deficiency. J Child Neurol 2021; 36:1189-1199. [PMID: 34015244 PMCID: PMC8605041 DOI: 10.1177/08830738211012804] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We examined safety, tolerability, and efficacy of SGS-742, a γ-aminobutyric acid B (GABA-B) receptor antagonist, in patients with succinic semialdehyde dehydrogenase deficiency. This was a single-center randomized, double-blind crossover phase II clinical trial of SGS-742 versus placebo in patients with succinic semialdehyde dehydrogenase deficiency. Procedures included transcranial magnetic stimulation and the Adaptive Behavior Assessment Scale. Nineteen subjects were consented and enrolled; the mean age was 14.0 ± 7.5 years and 11 (58%) were female. We did not find a significant effect of SGS-742 on the Adaptive Behavior Assessment Scale score, motor threshold, and paired-pulse stimulation. The difference in recruitment curve slopes between treatment groups was 0.003 (P = .09). There was no significant difference in incidence of adverse effects between drug and placebo arms. SGS-742 failed to produce improved cognition and normalization of cortical excitability as measured by the Adaptive Behavior Assessment Scale and transcranial magnetic stimulation. Our data do not support the current use of SGS-742 in succinic semialdehyde dehydrogenase deficiency.Trial registry number NCT02019667. Phase 2 Clinical Trial of SGS-742 Therapy in Succinic Semialdehyde Dehydrogenase Deficiency. https://clinicaltrials.gov/ct2/show/NCT02019667.
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Affiliation(s)
- John M. Schreiber
- NINDS NIH, Clinical Epilepsy Section, Bethesda, MD, USA
- Children’s National Hospital, Division of Epilepsy, Neurophysiology, and Critical Care Neurology, Washington, DC, USA
| | - Edythe Wiggs
- NINDS NIH, Office of the Clinical Director, Bethesda, MD, USA
| | - Rose Cuento
- NINDS NIH, Office of the Clinical Director, Bethesda, MD, USA
- NINDS NIH, Clinical Trials Unit, Bethesda, MD, USA
| | - Gina Norato
- NINDS NIH, Office of the Clinical Director, Bethesda, MD, USA
| | | | | | | | | | - Sara K. Inati
- NINDS NIH, Office of the Clinical Director, Bethesda, MD, USA
| | - K. Michael Gibson
- Washington State University, College of Pharmacy and Pharmaceutical Sciences, Department of Pharmacotherapy, Spokane, WA, USA
| | - Phillip L. Pearl
- Boston Children’s Hospital, Department of Epilepsy and Clinical Neurophysiology, Boston, MA, USA
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Ahmadi ZZ, DiBacco ML, Pearl PL. Speech Motor Function and Auditory Perception in Succinic Semialdehyde Dehydrogenase Deficiency: Toward Pre-Supplementary Motor Area (SMA) and SMA-Proper Dysfunctions. J Child Neurol 2021; 36:1210-1217. [PMID: 33757330 DOI: 10.1177/08830738211001210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study reviews the fundamental roles of pre-supplementary motor area (SMA) and SMA-proper responsible for speech-motor functions and auditory perception in succinic semialdehyde dehydrogenase (SSADH) deficiency. We comprehensively searched the databases of PubMed, Google Scholar, and the electronic journals Springer, PreQuest, and Science Direct associated with keywords SSADHD, SMA, auditory perception, speech, and motor with AND operator. Transcranial magnetic stimulation emerged for assessing excitability/inhibitory M1 functions, but its role in pre-SMA and SMA proper dysfunction remains unknown. There was a lack of data on resting-state and task-based functional magnetic resonance imaging (MRI), with a focus on passive and active tasks for both speech and music, in terms of analysis of SMA-related cortex and its connections. Children with SSADH deficiency likely experience a dysfunction in connectivity between SMA portions with cortical and subcortical areas contributing to disabilities in speech-motor functions and auditory perception. Early diagnosis of auditory-motor disabilities in children with SSADH deficiency by neuroimaging techniques invites opportunities for utilizing sensory-motor integration as future interventional strategies.
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Affiliation(s)
- Zohreh Ziatabar Ahmadi
- Department of Speech Therapy, School of Rehabilitation, Babol University of Medical Sciences, Babol, I.R. Iran
| | - Melissa L DiBacco
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Phillip L Pearl
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Walters DC, Lawrence R, Kirby T, Ahrendsen JT, Anderson MP, Roullet JB, Murphy EJ, Gibson KM. Postmortem Analyses in a Patient With Succinic Semialdehyde Dehydrogenase Deficiency (SSADHD): II. Histological, Lipid, and Gene Expression Outcomes in Regional Brain Tissue. J Child Neurol 2021; 36:1177-1188. [PMID: 33557678 PMCID: PMC8349921 DOI: 10.1177/0883073820987742] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
This study has extended previous metabolic measures in postmortem tissues (frontal and parietal lobes, pons, cerebellum, hippocampus, and cerebral cortex) obtained from a 37-year-old male patient with succinic semialdehyde dehydrogenase deficiency (SSADHD) who expired from SUDEP (sudden unexplained death in epilepsy). Histopathologic characterization of fixed cortex and hippocampus revealed mild to moderate astrogliosis, especially in white matter. Analysis of total phospholipid mass in all sections of the patient revealed a 61% increase in cortex and 51% decrease in hippocampus as compared to (n = 2-4) approximately age-matched controls. Examination of mass and molar composition of major phospholipid classes showed decreases in phospholipids enriched in myelin, such as phosphatidylserine, sphingomyelin, and ethanolamine plasmalogen. Evaluation of gene expression (RT2 Profiler PCR Arrays, GABA, glutamate; Qiagen) revealed dysregulation in 14/15 GABAA receptor subunits in cerebellum, parietal, and frontal lobes with the most significant downregulation in ∊, θ, ρ1, and ρ2 subunits (7.7-9.9-fold). GABAB receptor subunits were largely unaffected, as were ionotropic glutamate receptors. The metabotropic glutamate receptor 6 was consistently downregulated (maximum 5.9-fold) as was the neurotransmitter transporter (GABA), member 13 (maximum 7.3-fold). For other genes, consistent dysregulation was seen for interleukin 1β (maximum downregulation 9.9-fold) and synuclein α (maximal upregulation 6.5-fold). Our data provide unique insight into SSADHD brain function, confirming astrogliosis and lipid abnormalities previously observed in the null mouse model while highlighting long-term effects on GABAergic/glutamatergic gene expression in this disorder.
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Affiliation(s)
- DC Walters
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA
| | - R Lawrence
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND
| | - T Kirby
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA
| | - JT Ahrendsen
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - MP Anderson
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - J-B Roullet
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA
| | - EJ Murphy
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND
| | - KM Gibson
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA,Correspondence: Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Health Sciences Building Room 210C, Washington State University, 412 E. Spokane Falls Boulevard, Spokane, WA 99202-2131; phone 509-358-7954; fax 508-358-7667;
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Pearl PL, DiBacco ML, Papadelis C, Opladen T, Hanson E, Roullet JB, Gibson KM. Succinic Semialdehyde Dehydrogenase Deficiency: Review of the Natural History Study. J Child Neurol 2021; 36:1153-1161. [PMID: 33393837 PMCID: PMC8254814 DOI: 10.1177/0883073820981262] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The SSADHD Natural History Study was initiated in 2019 to define the natural course and identify biomarkers correlating with severity. METHODS The study is conducted by 4 institutions: BCH (US clinical), WSU (bioanalytical core), USF (biostatistical core), and Heidelberg (iNTD), with support from the family advocacy group (SSADH Association). Recruitment goals were to study 20 patients on-site at BCH, 10 with iNTD, and 25 as a standard-of care cohort. RESULTS At this half-way point of this longitudinal study, 28 subjects have been recruited (57% female, mean 9 years, range 18 months-40 years). Epilepsy is present in half and increases in incidence and severity, as do psychiatric symptoms, in adolescence and adulthood. The average Full Scale IQ (FSIQ) was 53 (Verbal score of 56, Non Verbal score of 49), and half scored as having ASD. Although there was no correlation between gene variant and phenotypic severity, there were extreme cases of lowest functioning in one individual and highest in another that may have genotype-phenotype correlation. The most common EEG finding was mild background slowing with rare epileptiform activity, whereas high-density EEG and magnetoencephalography showed reduction in the gamma frequency band consistent with GABAergic dysfunction. MR spectroscopy showed elevations in the GABA/NAA ratio in all regions studied with no crossover between subjects and controls. CONCLUSIONS The SSADH Natural History Study is providing a unique opportunity to study the complex pathophysiology longitudinally and derive electrophysiologic, neuroimaging, and laboratory data for correlation and to serve as biomarkers for clinical trials and prognostic assessments in this ultra-rare inherited disorder of GABA metabolism.
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Affiliation(s)
- Phillip L Pearl
- Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA
| | - Melissa L DiBacco
- Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA
| | - Christos Papadelis
- Jane and John Justin Neuroscience Center, Cook Children’s Health Care System, 1500 Cooper Street, Fort Worth, TX 76104, USA; Department of Pediatrics, TCU and UNTHSC School of Medicine, Fort Worth, TX, USA; Laboratory of Children’s Brain Dynamics, Division of Newborn Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Thomas Opladen
- Department of Child Neurology and Metabolic Disorders, University Children’s Hospital, Heidelberg, Germany
| | - Ellen Hanson
- Neurodevelopmental Core, Boston Children’s Hospital, Harvard Medical School, Boston, MA
| | - Jean-Baptiste Roullet
- College of Pharmacy, Department of Pharmacotherapy, Washington State University, Spokane, WA
| | - K. Michael Gibson
- College of Pharmacy, Department of Pharmacotherapy, Washington State University, Spokane, WA
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DiBacco ML, Pop A, Salomons GS, Hanson E, Roullet JB, Gibson KM, Pearl PL. Novel ALDH5A1 variants and genotype: Phenotype correlation in SSADH deficiency. Neurology 2020; 95:e2675-e2682. [PMID: 32887777 DOI: 10.1212/wnl.0000000000010730] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 06/04/2020] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE To determine genotype-phenotype correlation in succinic semialdehyde dehydrogenase (SSADH) deficiency. METHODS ALDH5A1 variants were studied with phenotype correlation in the SSADH natural history study. Assignment of gene variant pathogenicity was based on in silico testing and in vitro enzyme activity after site-directed mutagenesis and expression in HEK293 cells. Phenotypic scoring used a Clinical Severity Score (CSS) designed for the natural history study. RESULTS Twenty-four patients were enrolled (10 male, 14 female, median age 8.2 years). There were 24 ALDH5A1 variants, including 7 novel pathogenic variants: 2 missense, 3 splice site, and 2 frameshift. Four previously reported variants were identified in >5% of unrelated families. There was a correlation with age and presence (p = 0.003) and severity (p = 0.002) of epilepsy and with obsessive-compulsive disorder (OCD) (p = 0.016). The median IQ score was 53 (Q25-Q75, 49-61). There was no overall correlation between the gene variants and the CSS, although a novel missense variant was associated with the mildest phenotype by CSS in the only patient with a normal IQ, whereas a previously reported variant was consistently associated with the most severe phenotype. CONCLUSIONS Seven novel pathogenic and one previously unpublished benign ALDH5A1 variants were detected. There is an age-dependent association with worsening of epilepsy and presence of OCD in SSADH deficiency. Overall, there does not appear to be a correlation between genotype and phenotypic severity in this cohort of 24 patients. We did find a suspected correlation between a novel pathogenic missense variant and high functionality, and a previously reported pathogenic missense variant and maximal severity.
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Affiliation(s)
- Melissa L DiBacco
- From the Department of Neurology (M.L.D., P.L.P.) and Neurodevelopmental Core (E.H.), Boston Children's Hospital, Harvard Medical School, MA; Metabolic Unit, Department of Clinical Chemistry, Vrije Universiteit Amsterdam (A.P., G.S.S.), and Department of Genetic Metabolic Diseases, Emma Children's Hospital, University of Amsterdam (G.S.S.), Amsterdam Neuroscience and Amsterdam Gastroenterology & Metabolism, Amsterdam University Medical Centers, the Netherlands; and College of Pharmacy, Department of Pharmacotherapy (J.-B.R., K.M.G.), Washington State University, Spokane
| | - Ana Pop
- From the Department of Neurology (M.L.D., P.L.P.) and Neurodevelopmental Core (E.H.), Boston Children's Hospital, Harvard Medical School, MA; Metabolic Unit, Department of Clinical Chemistry, Vrije Universiteit Amsterdam (A.P., G.S.S.), and Department of Genetic Metabolic Diseases, Emma Children's Hospital, University of Amsterdam (G.S.S.), Amsterdam Neuroscience and Amsterdam Gastroenterology & Metabolism, Amsterdam University Medical Centers, the Netherlands; and College of Pharmacy, Department of Pharmacotherapy (J.-B.R., K.M.G.), Washington State University, Spokane
| | - Gajja S Salomons
- From the Department of Neurology (M.L.D., P.L.P.) and Neurodevelopmental Core (E.H.), Boston Children's Hospital, Harvard Medical School, MA; Metabolic Unit, Department of Clinical Chemistry, Vrije Universiteit Amsterdam (A.P., G.S.S.), and Department of Genetic Metabolic Diseases, Emma Children's Hospital, University of Amsterdam (G.S.S.), Amsterdam Neuroscience and Amsterdam Gastroenterology & Metabolism, Amsterdam University Medical Centers, the Netherlands; and College of Pharmacy, Department of Pharmacotherapy (J.-B.R., K.M.G.), Washington State University, Spokane
| | - Ellen Hanson
- From the Department of Neurology (M.L.D., P.L.P.) and Neurodevelopmental Core (E.H.), Boston Children's Hospital, Harvard Medical School, MA; Metabolic Unit, Department of Clinical Chemistry, Vrije Universiteit Amsterdam (A.P., G.S.S.), and Department of Genetic Metabolic Diseases, Emma Children's Hospital, University of Amsterdam (G.S.S.), Amsterdam Neuroscience and Amsterdam Gastroenterology & Metabolism, Amsterdam University Medical Centers, the Netherlands; and College of Pharmacy, Department of Pharmacotherapy (J.-B.R., K.M.G.), Washington State University, Spokane
| | - Jean-Baptiste Roullet
- From the Department of Neurology (M.L.D., P.L.P.) and Neurodevelopmental Core (E.H.), Boston Children's Hospital, Harvard Medical School, MA; Metabolic Unit, Department of Clinical Chemistry, Vrije Universiteit Amsterdam (A.P., G.S.S.), and Department of Genetic Metabolic Diseases, Emma Children's Hospital, University of Amsterdam (G.S.S.), Amsterdam Neuroscience and Amsterdam Gastroenterology & Metabolism, Amsterdam University Medical Centers, the Netherlands; and College of Pharmacy, Department of Pharmacotherapy (J.-B.R., K.M.G.), Washington State University, Spokane
| | - K Michael Gibson
- From the Department of Neurology (M.L.D., P.L.P.) and Neurodevelopmental Core (E.H.), Boston Children's Hospital, Harvard Medical School, MA; Metabolic Unit, Department of Clinical Chemistry, Vrije Universiteit Amsterdam (A.P., G.S.S.), and Department of Genetic Metabolic Diseases, Emma Children's Hospital, University of Amsterdam (G.S.S.), Amsterdam Neuroscience and Amsterdam Gastroenterology & Metabolism, Amsterdam University Medical Centers, the Netherlands; and College of Pharmacy, Department of Pharmacotherapy (J.-B.R., K.M.G.), Washington State University, Spokane
| | - Phillip L Pearl
- From the Department of Neurology (M.L.D., P.L.P.) and Neurodevelopmental Core (E.H.), Boston Children's Hospital, Harvard Medical School, MA; Metabolic Unit, Department of Clinical Chemistry, Vrije Universiteit Amsterdam (A.P., G.S.S.), and Department of Genetic Metabolic Diseases, Emma Children's Hospital, University of Amsterdam (G.S.S.), Amsterdam Neuroscience and Amsterdam Gastroenterology & Metabolism, Amsterdam University Medical Centers, the Netherlands; and College of Pharmacy, Department of Pharmacotherapy (J.-B.R., K.M.G.), Washington State University, Spokane.
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10
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Brown M, Turgeon C, Rinaldo P, Pop A, Salomons GS, Roullet J, Gibson KM. Longitudinal metabolomics in dried bloodspots yields profiles informing newborn screening for succinic semialdehyde dehydrogenase deficiency. JIMD Rep 2020; 53:29-38. [PMID: 32395407 PMCID: PMC7203655 DOI: 10.1002/jmd2.12075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 08/12/2019] [Accepted: 08/13/2019] [Indexed: 12/23/2022] Open
Abstract
Analyses of 19 amino acids, 38 acylcarnitines, and 3 creatine analogues (https://clir.mayo.edu) were implemented to test the hypothesis that succinic semialdehyde dehydrogenase deficiency (SSADHD) could be identified in dried bloodspots (DBS) using currently available newborn screening methodology. The study population included 17 post-newborn SSADHD DBS (age range 0.8-38 years; median, 8.2 years; 10 M; controls, 129-353 age-matched individuals, mixed gender) and 10 newborn SSADHD DBS (including first and second screens from 3 of 7 patients). Low (informative) markers in post-newborn DBS included C2- and C4-OH carnitines, ornithine, histidine and creatine, with no gender differences. For newborn DBS, informative markers included C2-, C3-, C4- and C4-OH carnitines, creatine and ornithine. Of these, only creatine demonstrated a significant change with age, revealing an approximate 4-fold decrease. We conclude that quantitation of short-chain acylcarnitines, creatine, and ornithine provides a newborn DBS profile with potential as a first tier screening tool for early detection of SSADHD. This first tier evaluation can be readily verified using a previously described second tier liquid chromatography-tandem mass spectrometry method for γ-hydroxybutyric acid in the same DBS. More extensive evaluation of this first/second tier screening approach is needed in a larger population.
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Affiliation(s)
- Madalyn Brown
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical SciencesWashington State UniversitySpokaneWashington
| | - Coleman Turgeon
- Mayo Clinic, Department of Laboratory Medicine and PathologyRochesterMinnesota
| | - Piero Rinaldo
- Mayo Clinic, Department of Laboratory Medicine and PathologyRochesterMinnesota
| | - Ana Pop
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical CentersVrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & MetabolismAmsterdamThe Netherlands
| | - Gajja S. Salomons
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical CentersVrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & MetabolismAmsterdamThe Netherlands
- Department of Genetic Metabolic Diseases, Amsterdam University Medical CentersUniversity of Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & MetabolismAmsterdamThe Netherlands
| | - Jean‐Baptiste Roullet
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical SciencesWashington State UniversitySpokaneWashington
| | - K. Michael Gibson
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical SciencesWashington State UniversitySpokaneWashington
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11
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Didiasova M, Banning A, Brennenstuhl H, Jung-Klawitter S, Cinquemani C, Opladen T, Tikkanen R. Succinic Semialdehyde Dehydrogenase Deficiency: An Update. Cells 2020; 9:cells9020477. [PMID: 32093054 PMCID: PMC7072817 DOI: 10.3390/cells9020477] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 02/14/2020] [Accepted: 02/17/2020] [Indexed: 02/06/2023] Open
Abstract
Succinic semialdehyde dehydrogenase deficiency (SSADH-D) is a genetic disorder that results from the aberrant metabolism of the neurotransmitter γ-amino butyric acid (GABA). The disease is caused by impaired activity of the mitochondrial enzyme succinic semialdehyde dehydrogenase. SSADH-D manifests as varying degrees of mental retardation, autism, ataxia, and epileptic seizures, but the clinical picture is highly heterogeneous. So far, there is no approved curative therapy for this disease. In this review, we briefly summarize the molecular genetics of SSADH-D, the past and ongoing clinical trials, and the emerging features of the molecular pathogenesis, including redox imbalance and mitochondrial dysfunction. The main aim of this review is to discuss the potential of further therapy approaches that have so far not been tested in SSADH-D, such as pharmacological chaperones, read-through drugs, and gene therapy. Special attention will also be paid to elucidating the role of patient advocacy organizations in facilitating research and in the communication between researchers and patients.
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Affiliation(s)
- Miroslava Didiasova
- Institute of Biochemistry, Medical Faculty, University of Giessen, Friedrichstrasse 24, 35392 Giessen, Germany; (M.D.); (A.B.)
| | - Antje Banning
- Institute of Biochemistry, Medical Faculty, University of Giessen, Friedrichstrasse 24, 35392 Giessen, Germany; (M.D.); (A.B.)
| | - Heiko Brennenstuhl
- Division of Neuropediatrics and Metabolic Medicine, Department of General Pediatrics, University Children’s Hospital Heidelberg, 69120 Heidelberg, Germany; (H.B.); (S.J.-K.); (T.O.)
| | - Sabine Jung-Klawitter
- Division of Neuropediatrics and Metabolic Medicine, Department of General Pediatrics, University Children’s Hospital Heidelberg, 69120 Heidelberg, Germany; (H.B.); (S.J.-K.); (T.O.)
| | | | - Thomas Opladen
- Division of Neuropediatrics and Metabolic Medicine, Department of General Pediatrics, University Children’s Hospital Heidelberg, 69120 Heidelberg, Germany; (H.B.); (S.J.-K.); (T.O.)
| | - Ritva Tikkanen
- Institute of Biochemistry, Medical Faculty, University of Giessen, Friedrichstrasse 24, 35392 Giessen, Germany; (M.D.); (A.B.)
- Correspondence: ; Tel.: +49-641-9947-420
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12
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Brown M, Turgeon C, Rinaldo P, Roullet JB, Gibson KM. Temporal metabolomics in dried bloodspots suggests multipathway disruptions in aldh5a1 -/- mice, a model of succinic semialdehyde dehydrogenase deficiency. Mol Genet Metab 2019; 128:397-408. [PMID: 31699650 DOI: 10.1016/j.ymgme.2019.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 08/26/2019] [Accepted: 10/05/2019] [Indexed: 02/08/2023]
Abstract
Succinic semialdehyde dehydrogenase (SSADH) deficiency (SSADHD; OMIM 271980) is a rare disorder featuring accumulation of neuroactive 4-aminobutyric acid (GABA; γ-aminobutyric acid, derived from glutamic acid) and 4-hydroxybutyric acid (γ-hydroxybutyric acid; GHB, a short-chain fatty acid analogue of GABA). Elevated GABA is predicted to disrupt the GABA shunt linking GABA transamination to the Krebs cycle and maintaining the balance of excitatory:inhibitory neurotransmitters. Similarly, GHB (or a metabolite) is predicted to impact β-oxidation flux. We explored these possibilities employing temporal metabolomics of dried bloodspots (DBS), quantifying amino acids, acylcarnitines, and guanidino- metabolites, derived from aldh5a1+/+, aldh5a1+/- and aldh5a1-/- mice (aldehyde dehydrogenase 5a1 = SSADH) at day of life (DOL) 20 and 42 days. At DOL 20, aldh5a1-/- mice had elevated C6 dicarboxylic (adipic acid) and C14 carnitines and threonine, combined with a significantly elevated ratio of threonine/[aspartic acid + alanine], in comparison to aldh5a1+/+ mice. Conversely, at DOL 42 aldh5a1-/- mice manifested decreased short chain carnitines (C0-C6), valine and glutamine, in comparison to aldh5a1+/+ mice. Guanidino species, including creatinine, creatine and guanidinoacetic acid, evolved from normal levels (DOL 20) to significantly decreased values at DOL 42 in aldh5a1-/- as compared to aldh5a1+/+ mice. Our results provide a novel temporal snapshot of the evolving metabolic profile of aldh5a1-/- mice while highlighting new pathomechanisms in SSADHD.
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Affiliation(s)
- Madalyn Brown
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, United States of America
| | - Coleman Turgeon
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States of America
| | - Piero Rinaldo
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States of America
| | - Jean-Baptiste Roullet
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, United States of America
| | - K Michael Gibson
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, United States of America.
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13
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Roles of taurine in cognitive function of physiology, pathologies and toxication. Life Sci 2019; 231:116584. [DOI: 10.1016/j.lfs.2019.116584] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/09/2019] [Accepted: 06/17/2019] [Indexed: 11/23/2022]
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14
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In vitro modeling of experimental succinic semialdehyde dehydrogenase deficiency (SSADHD) using brain-derived neural stem cells. PLoS One 2017; 12:e0186919. [PMID: 29053743 PMCID: PMC5650182 DOI: 10.1371/journal.pone.0186919] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Accepted: 10/10/2017] [Indexed: 12/23/2022] Open
Abstract
We explored the utility of neural stem cells (NSCs) as an in vitro model for evaluating preclinical therapeutics in succinic semialdehyde dehydrogenase-deficient (SSADHD) mice. NSCs were obtained from aldh5a1+/+ and aldh5a1-/- mice (aldh5a1 = aldehyde dehydrogenase 5a1 = SSADH). Multiple parameters were evaluated including: (1) production of GHB (γ-hydroxybutyrate), the biochemical hallmark of SSADHD; (2) rescue from cell death with the dual mTOR (mechanistic target of rapamycin) inhibitor, XL-765, an agent previously shown to rescue aldh5a1-/- mice from premature lethality; (3) mitochondrial number, total reactive oxygen species, and mitochondrial superoxide production, all previously documented as abnormal in aldh5a1-/- mice; (4) total ATP levels and ATP consumption; and (5) selected gene expression profiles associated with epilepsy, a prominent feature in both experimental and human SSADHD. Patterns of dysfunction were observed in all of these parameters and mirrored earlier findings in aldh5a1-/- mice. Patterns of dysregulated gene expression between hypothalamus and NSCs centered on ion channels, GABAergic receptors, and inflammation, suggesting novel pathomechanisms as well as a developmental ontogeny for gene expression potentially associated with the murine epileptic phenotype. The NSC model of SSADHD will be valuable in providing a first-tier screen for centrally-acting therapeutics and prioritizing therapeutic concepts of preclinical animal studies applicable to SSADHD.
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Vogel KR, Arning E, Bottiglieri T, Gibson KM. Multicompartment analysis of protein-restricted phenylketonuric mice reveals amino acid imbalances in brain. J Inherit Metab Dis 2017; 40:227-235. [PMID: 27761676 DOI: 10.1007/s10545-016-9984-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 09/12/2016] [Accepted: 09/18/2016] [Indexed: 02/05/2023]
Abstract
BACKGROUND The mainstay of therapy for phenylketonuria (PKU) remains dietary protein restriction. Developmental and neurocognitive outcomes for patients, however, remain suboptimal. We tested the hypothesis that mice with PKU receiving protein-restricted diets would reveal disruptions of brain amino acids that shed light on these neurocognitive deficits. METHOD Phenylalanine hydroxylase-deficient (PKU) mice and parallel controls (both wild-type and heterozygous) were fed custom diets containing 18, 6, and 4 % protein for 3 weeks, after which tissues (brain, liver, sera) were collected for amino acid analysis profiling. RESULTS Phenylalanine (phe) was increased in all tissues (p < 0.0001) of PKU mice and improved with protein restriction. In sera, decreased tyrosine (p < 0.01) was corrected (defined as not significantly different from the level in control mice receiving 18 % chow) with protein restriction, whereas protein restriction significantly increased many other amino acids. A similar trend for increased amino acid levels with protein restriction was also observed in liver. In brain, the effects of protein restriction on large neutral amino acids (LNAAs) were variable, with some deficit correction (threonine, methionine, glutamine) and no correction of tyrosine under any dietary paradigm. Protein restriction (4 % diet) in PKU mice significantly decreased lysine, arginine, taurine, glutamate, asparagine, and serine which had been comparable to control mice under 18 % protein intake. CONCLUSION Depletion of taurine, glutamate, and serine in the brain of PKU mice with dietary protein restriction may provide new insight into neurocognitive deficits of PKU.
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Affiliation(s)
- Kara R Vogel
- Division of Experimental and Systems Pharmacology, College of Pharmacy, Washington State University, Pharmaceutical and Biomedical Sciences Building, Room 347, 412 E. Spokane Falls Blvd, Spokane, WA, 99204, USA
| | - Erland Arning
- Kimberly H. Courtwright and Joseph W. Summers Institute of Metabolic Disease, Baylor Research Institute, Dallas, TX, USA
| | - Teodoro Bottiglieri
- Kimberly H. Courtwright and Joseph W. Summers Institute of Metabolic Disease, Baylor Research Institute, Dallas, TX, USA
| | - K Michael Gibson
- Division of Experimental and Systems Pharmacology, College of Pharmacy, Washington State University, Pharmaceutical and Biomedical Sciences Building, Room 347, 412 E. Spokane Falls Blvd, Spokane, WA, 99204, USA.
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Vogel KR, Ainslie GR, Roullet JB, McConnell A, Gibson KM. In vitro toxicological evaluation of NCS-382, a high-affinity antagonist of γ-hydroxybutyrate (GHB) binding. Toxicol In Vitro 2017; 40:196-202. [PMID: 28119166 DOI: 10.1016/j.tiv.2017.01.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 01/16/2017] [Accepted: 01/19/2017] [Indexed: 12/17/2022]
Abstract
γ-Hydroxybutyric acid (GHB), a minor metabolite of the inhibitory neurotransmitter GABA, can accumulate to significant concentrations in the heritable disorder of GABA degradation, succinic semialdehyde dehydrogenase (SSADH) deficiency (SSADHD). Moreover, GHB may be employed in therapeutic settings (treatment of narcolepsy), as well as instances of illicit activity, including acquaintance sexual assault and the induction of euphoria. High-affinity binding sites for GHB in the brain have been identified, although the absolute identity of these receptors remains unclear. Pharmacological antagonism of GHB binding may have multiple instances of therapeutic relevance. The high affinity GHB receptor antagonist, NCS-382 (6,7,8,9-tetrahydro-5-hydroxy-5H-benzo-cyclohept-6-ylideneacetic acid) has not been piloted in humans. To address the potential clinical utility of NCS-382, we have piloted initial studies of its toxicology in HepG2 and primary hepatocyte cells. At high dose (0.5mM), NCS-382 showed no capacity for inhibition of microsomal CYPs (CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6 and 3A4) and minimal potential for activation of xenobiotic nuclear receptors. Additional cellular integrity and functional assays (viability, oxidative stress, apoptosis, ATP production) revealed little evidence for cytotoxicity, and a low degree of dysregulation of >370 genes actively engaged in the mediation of cellular toxicity. In vitro testing indicates a low probability of cellular toxicity associated with NCS-382.
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Affiliation(s)
- K R Vogel
- Department of Pharmacotherapy, College of Pharmacy, Washington State University, Spokane, WA, United States
| | - G R Ainslie
- Department of Pharmacotherapy, College of Pharmacy, Washington State University, Spokane, WA, United States
| | - J-B Roullet
- Department of Pharmacotherapy, College of Pharmacy, Washington State University, Spokane, WA, United States
| | | | - K M Gibson
- Department of Pharmacotherapy, College of Pharmacy, Washington State University, Spokane, WA, United States.
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