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Schoeler NE, Marston L, Lyons L, Halsall S, Jain R, Titre-Johnson S, Balogun M, Heales SJR, Eaton S, Orford M, Neal E, Reilly C, Eltze C, Stephen E, Mallick AA, O'Callaghan F, Agrawal S, Parker A, Kirkpatrick M, Brunklaus A, McLellan A, McCullagh H, Samanta R, Kneen R, Tan HJ, Devlin A, Prasad M, Rattihalli R, Basu H, Desurkar A, Williams R, Fallon P, Nazareth I, Freemantle N, Cross JH. Classic ketogenic diet versus further antiseizure medicine in infants with drug-resistant epilepsy (KIWE): a UK, multicentre, open-label, randomised clinical trial. Lancet Neurol 2023; 22:1113-1124. [PMID: 37977712 DOI: 10.1016/s1474-4422(23)00370-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 08/08/2023] [Accepted: 09/21/2023] [Indexed: 11/19/2023]
Abstract
BACKGROUND Many infancy-onset epilepsies have poor prognosis for seizure control and neurodevelopmental outcome. Ketogenic diets can improve seizures in children older than 2 years and adults who are unresponsive to antiseizure medicines. We aimed to establish the efficacy of a classic ketogenic diet at reducing seizure frequency compared with further antiseizure medicine in infants with drug-resistant epilepsy. METHODS In this phase 4, open-label, multicentre, randomised clinical trial, infants aged 1-24 months with drug-resistant epilepsy (defined as four or more seizures per week and two or more previous antiseizure medications) were recruited from 19 hospitals in the UK. Following a 1-week or 2-week observation period, participants were randomly assigned using a computer-generated schedule, without stratification, to either a classic ketogenic diet or a further antiseizure medication for 8 weeks. Treatment allocation was masked from research nurses involved in patient care, but not from participants. The primary outcome was the median number of seizures per day, recorded during weeks 6-8. All analyses were by modified intention to treat, which included all participants with available data. Participants were followed for up to 12 months. All serious adverse events were recorded. The trial is registered with the European Union Drug Regulating Authorities Clinical Trials Database (2013-002195-40). The trial was terminated early before all participants had reached 12 months of follow-up because of slow recruitment and end of funding. FINDINGS Between Jan 1, 2015, and Sept 30, 2021, 155 infants were assessed for eligibility, of whom 136 met inclusion criteria and were randomly assigned; 75 (55%) were male and 61 (45%) were female. 78 infants were assigned to a ketogenic diet and 58 to antiseizure medication, of whom 61 and 47, respectively, had available data and were included in the modifified intention-to-treat analysis at week 8. The median number of seizures per day during weeks 6-8, accounting for baseline rate and randomised group, was similar between the ketogenic diet group (5 [IQR 1-16]) and antiseizure medication group (3 [IQR 2-11]; IRR 1·33, 95% CI 0·84-2·11). A similar number of infants with at least one serious adverse event was reported in both groups (40 [51%] of 78 participants in the ketogenic diet group and 26 [45%] of 58 participants in the antiseizure medication group). The most common serious adverse events were seizures in both groups. Three infants died during the trial, all of whom were randomly assigned a ketogenic diet: one child (who also had dystonic cerebral palsy) was found not breathing at home; one child died suddenly and unexpectedly at home; and one child went into cardiac arrest during routine surgery under anaesthetic. The deaths were judged unrelated to treatment by local principal investigators and confirmed by the data safety monitoring committee. INTERPRETATION In this phase 4 trial, a ketogenic diet did not differ in efficacy and tolerability to a further antiseizure medication, and it appears to be safe to use in infants with drug-resistant epilepsy. A ketogenic diet could be a treatment option in infants whose seizures continue despite previously trying two antiseizure medications. FUNDING National Institute for Health and Care Research.
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Affiliation(s)
- Natasha E Schoeler
- Developmental Neurosciences Research and Teaching Department, University College London Great Ormond Street Institute of Child Health, London, UK; Dietetics, Great Ormond Street Hospital for Children, London, UK
| | - Louise Marston
- Department of Primary Care and Population Health, University College London, London, UK; PRIMENT Clinical Trials Unit, University College London, London, UK
| | - Laura Lyons
- Developmental Neurosciences Research and Teaching Department, University College London Great Ormond Street Institute of Child Health, London, UK
| | - Sally Halsall
- Developmental Neurosciences Research and Teaching Department, University College London Great Ormond Street Institute of Child Health, London, UK
| | - Ruchika Jain
- Developmental Neurosciences Research and Teaching Department, University College London Great Ormond Street Institute of Child Health, London, UK
| | - Siobhan Titre-Johnson
- Developmental Neurosciences Research and Teaching Department, University College London Great Ormond Street Institute of Child Health, London, UK
| | - Maryam Balogun
- Developmental Neurosciences Research and Teaching Department, University College London Great Ormond Street Institute of Child Health, London, UK
| | - Simon J R Heales
- Genetics and Genomic Medicine, University College London Great Ormond Street Institute of Child Health, London, UK
| | - Simon Eaton
- Stem Cells and Regenerative Medicine Section, University College London Great Ormond Street Institute of Child Health, London, UK
| | - Michael Orford
- Genetics and Genomic Medicine, University College London Great Ormond Street Institute of Child Health, London, UK
| | - Elizabeth Neal
- Developmental Neurosciences Research and Teaching Department, University College London Great Ormond Street Institute of Child Health, London, UK
| | - Colin Reilly
- Research Department, Young Epilepsy, Lingfield, Surrey, UK
| | - Christin Eltze
- Paediatric Neurosciences, Great Ormond Street Hospital for Children, London, UK
| | - Elma Stephen
- Child Neurology Service, Royal Aberdeen Children's Hospital, Aberdeen, UK
| | - Andrew A Mallick
- Department of Paediatric Neurology, Bristol Royal Hospital for Children, Bristol, UK
| | - Finbar O'Callaghan
- Developmental Neurosciences Research and Teaching Department, University College London Great Ormond Street Institute of Child Health, London, UK
| | - Shakti Agrawal
- Department of Neurology, Birmingham Children's Hospital, Birmingham, UK
| | - Alasdair Parker
- Clinical Medical School, University of Cambridge, Cambridge, UK
| | | | - Andreas Brunklaus
- Paediatric Neurosciences Unit, Royal Hospital for Children, Glasgow, UK
| | - Ailsa McLellan
- Department of Paediatric Neurosciences, Royal Hospital for Sick Children, Edinburgh, UK
| | - Helen McCullagh
- Department of Paediatric Neurology, Leeds Children's Hospital, Leeds, UK
| | - Rajib Samanta
- Department of Paediatric Neurology, University Hospital of Leicester, Leicester, UK
| | - Rachel Kneen
- Department of Neurology, Alder Hey Children's Hospital, Liverpool, UK
| | - Hui Jeen Tan
- Department of Paediatric Neurology, Royal Manchester Children's Hospital, Manchester, UK
| | - Anita Devlin
- Department of Paediatric Neurology, Great North Children's Hospital, Newcastle, UK
| | - Manish Prasad
- Department of Paediatric Neurology, Queens Medical Centre, Nottingham, UK
| | - Rohini Rattihalli
- Department of Paediatric Neurology, Oxford University Hospitals, Oxford, UK
| | - Helen Basu
- Department of Paediatric Neurology, Royal Preston Hospital, Preston, UK
| | - Archana Desurkar
- Neurology Department, Sheffield Children's Hospital, Sheffield, UK
| | - Ruth Williams
- Children's Neurosciences Centre, Evelina London Children's Hospital, London, UK
| | - Penny Fallon
- Department of Paediatric Neurology, St George's Hospital, London, UK
| | - Irwin Nazareth
- PRIMENT Clinical Trials Unit, University College London, London, UK
| | - Nick Freemantle
- Institute of Clinical Trials and Methodology, University College London, London, UK
| | - J Helen Cross
- Developmental Neurosciences Research and Teaching Department, University College London Great Ormond Street Institute of Child Health, London, UK; Paediatric Neurosciences, Great Ormond Street Hospital for Children, London, UK.
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Schoeler NE, Orford M, Vivekananda U, Simpson Z, Van de Bor B, Smith H, Balestrini S, Rutherford T, Brennan E, McKenna J, Lambert B, Barker T, Jackson R, Williams RSB, Sisodiya SM, Eaton S, Heales SJR, Cross JH, Walker MC. K.Vita: a feasibility study of a blend of medium chain triglycerides to manage drug-resistant epilepsy. Brain Commun 2021; 3:fcab160. [PMID: 34729477 PMCID: PMC8557697 DOI: 10.1093/braincomms/fcab160] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/18/2021] [Accepted: 05/25/2021] [Indexed: 11/14/2022] Open
Abstract
This prospective open-label feasibility study aimed to evaluate acceptability, tolerability and compliance with dietary intervention with K.Vita, a medical food containing a unique ratio of decanoic acid to octanoic acid, in individuals with drug-resistant epilepsy. Adults and children aged 3-18 years with drug-resistant epilepsy took K.Vita daily whilst limiting high-refined sugar food and beverages. K.Vita was introduced incrementally with the aim of achieving ≤35% energy requirements for children or 240 ml for adults. Primary outcome measures were assessed by study completion, participant diary, acceptability questionnaire and K.Vita intake. Reduction in seizures or paroxysmal events was a secondary outcome. 23/35 (66%) children and 18/26 (69%) adults completed the study; completion rates were higher when K.Vita was introduced more gradually. Gastrointestinal disturbances were the primary reason for discontinuation, but symptoms were similar to those reported from ketogenic diets and incidence decreased over time. At least three-quarters of participants/caregivers reported favourably on sensory attributes of K.Vita, such as taste, texture and appearance, and ease of use. Adults achieved a median intake of 240 ml K.Vita, and children 120 ml (19% daily energy). Three children and one adult had ß-hydroxybutyrate >1 mmol/l. There was 50% (95% CI 39-61%) reduction in mean frequency of seizures/events. Reduction in seizures or paroxysmal events correlated significantly with blood concentrations of medium chain fatty acids (C10 and C8) but not ß-hydroxybutyrate. K.Vita was well accepted and tolerated. Side effects were mild and resolved with dietetic support. Individuals who completed the study complied with K.Vita and additional dietary modifications. Dietary intervention had a beneficial effect on frequency of seizures or paroxysmal events, despite absent or very low levels of ketosis. We suggest that K.Vita may be valuable to those with drug-resistant epilepsy, particularly those who cannot tolerate or do not have access to ketogenic diets, and may allow for more liberal dietary intake compared to ketogenic diets, with mechanisms of action perhaps unrelated to ketosis. Further studies of effectiveness of K.Vita are warranted.
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Affiliation(s)
- Natasha E Schoeler
- UCL Great Ormond Street Institute of Child Health, London, UK.,Great Ormond Street Hospital for Children, London, UK
| | - Michael Orford
- UCL Great Ormond Street Institute of Child Health, London, UK
| | - Umesh Vivekananda
- National Hospital for Neurology and Neurosurgery, London, UK.,UCL Queen Square Institute of Neurology, London, UK
| | - Zoe Simpson
- Great Ormond Street Hospital for Children, London, UK
| | | | - Hannah Smith
- Great Ormond Street Hospital for Children, London, UK
| | - Simona Balestrini
- UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Chalfont-St-Peter, UK
| | | | | | | | | | - Tom Barker
- Vitaflo (International) Ltd, Liverpool, UK
| | | | - Robin S B Williams
- Department of Biological Sciences, Royal Holloway University of London, Surrey, UK
| | - Sanjay M Sisodiya
- UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Chalfont-St-Peter, UK
| | - Simon Eaton
- UCL Great Ormond Street Institute of Child Health, London, UK
| | - Simon J R Heales
- UCL Great Ormond Street Institute of Child Health, London, UK.,Great Ormond Street Hospital for Children, London, UK.,National Hospital for Neurology and Neurosurgery, London, UK.,UCL Queen Square Institute of Neurology, London, UK
| | - J Helen Cross
- UCL Great Ormond Street Institute of Child Health, London, UK
| | - Matthew C Walker
- National Hospital for Neurology and Neurosurgery, London, UK.,UCL Queen Square Institute of Neurology, London, UK
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3
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Rossignoli G, Krämer K, Lugarà E, Alrashidi H, Pope S, De La Fuente Barrigon C, Barwick K, Bisello G, Ng J, Counsell J, Lignani G, Heales SJR, Bertoldi M, Barral S, Kurian MA. Aromatic l-amino acid decarboxylase deficiency: a patient-derived neuronal model for precision therapies. Brain 2021; 144:2443-2456. [PMID: 33734312 PMCID: PMC8418346 DOI: 10.1093/brain/awab123] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 01/25/2021] [Accepted: 02/08/2021] [Indexed: 11/13/2022] Open
Abstract
Aromatic l-amino acid decarboxylase (AADC) deficiency is a complex inherited neurological disorder of monoamine synthesis which results in dopamine and serotonin deficiency. The majority of affected individuals have variable, though often severe cognitive and motor delay, with a complex movement disorder and high risk of premature mortality. For most, standard pharmacological treatment provides only limited clinical benefit. Promising gene therapy approaches are emerging, though may not be either suitable or easily accessible for all patients. To characterize the underlying disease pathophysiology and guide precision therapies, we generated a patient-derived midbrain dopaminergic neuronal model of AADC deficiency from induced pluripotent stem cells. The neuronal model recapitulates key disease features, including absent AADC enzyme activity and dysregulated dopamine metabolism. We observed developmental defects affecting synaptic maturation and neuronal electrical properties, which were improved by lentiviral gene therapy. Bioinformatic and biochemical analyses on recombinant AADC predicted that the activity of one variant could be improved by l-3,4-dihydroxyphenylalanine (l-DOPA) administration; this hypothesis was corroborated in the patient-derived neuronal model, where l-DOPA treatment leads to amelioration of dopamine metabolites. Our study has shown that patient-derived disease modelling provides further insight into the neurodevelopmental sequelae of AADC deficiency, as well as a robust platform to investigate and develop personalized therapeutic approaches.
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Affiliation(s)
- Giada Rossignoli
- Developmental Neurosciences, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
- Biological Chemistry, NBM Department, University of Verona, 37134 Verona, Italy
| | - Karolin Krämer
- Developmental Neurosciences, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Eleonora Lugarà
- Clinical and Experimental Epilepsy, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Haya Alrashidi
- Genetics and Genomic Medicine, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Simon Pope
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | | | - Katy Barwick
- Developmental Neurosciences, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Giovanni Bisello
- Biological Chemistry, NBM Department, University of Verona, 37134 Verona, Italy
| | - Joanne Ng
- Developmental Neurosciences, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
- Gene Transfer Technology Group, EGA-Institute for Women's Health, University College London, London WC1E 6HU, UK
| | - John Counsell
- Developmental Neurosciences, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Gabriele Lignani
- Clinical and Experimental Epilepsy, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Simon J R Heales
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
- Centre for Inborn Errors of Metabolism, GOS Institute of Child Health, UniversCity College London, London WC1N 1EH, UK
| | - Mariarita Bertoldi
- Biological Chemistry, NBM Department, University of Verona, 37134 Verona, Italy
- Correspondence may also be addressed to: Prof Mariarita Bertoldi Department of Neuroscience, Biomedicine and Movement Sciences Biological Chemistry Section, Room 1.24 Strada le Grazie 8, 37134 Verona, Italy E-mail:
| | - Serena Barral
- Developmental Neurosciences, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Manju A Kurian
- Developmental Neurosciences, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
- Department of Neurology, Great Ormond Street Hospital, London WC1N 3JH, UK
- Correspondence to: Prof Manju Kurian Zayed Centre for Research UCL Great Ormond Street Institute of Child Health 20 Guilford St, London WC1N 1DZ, UK E-mail:
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4
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Ng J, Barral S, De La Fuente Barrigon C, Lignani G, Erdem FA, Wallings R, Privolizzi R, Rossignoli G, Alrashidi H, Heasman S, Meyer E, Ngoh A, Pope S, Karda R, Perocheau D, Baruteau J, Suff N, Antinao Diaz J, Schorge S, Vowles J, Marshall LR, Cowley SA, Sucic S, Freissmuth M, Counsell JR, Wade-Martins R, Heales SJR, Rahim AA, Bencze M, Waddington SN, Kurian MA. Gene therapy restores dopamine transporter expression and ameliorates pathology in iPSC and mouse models of infantile parkinsonism. Sci Transl Med 2021; 13:eaaw1564. [PMID: 34011628 PMCID: PMC7612279 DOI: 10.1126/scitranslmed.aaw1564] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 08/20/2020] [Accepted: 02/20/2021] [Indexed: 12/11/2022]
Abstract
Most inherited neurodegenerative disorders are incurable, and often only palliative treatment is available. Precision medicine has great potential to address this unmet clinical need. We explored this paradigm in dopamine transporter deficiency syndrome (DTDS), caused by biallelic loss-of-function mutations in SLC6A3, encoding the dopamine transporter (DAT). Patients present with early infantile hyperkinesia, severe progressive childhood parkinsonism, and raised cerebrospinal fluid dopamine metabolites. The absence of effective treatments and relentless disease course frequently leads to death in childhood. Using patient-derived induced pluripotent stem cells (iPSCs), we generated a midbrain dopaminergic (mDA) neuron model of DTDS that exhibited marked impairment of DAT activity, apoptotic neurodegeneration associated with TNFα-mediated inflammation, and dopamine toxicity. Partial restoration of DAT activity by the pharmacochaperone pifithrin-μ was mutation-specific. In contrast, lentiviral gene transfer of wild-type human SLC6A3 complementary DNA restored DAT activity and prevented neurodegeneration in all patient-derived mDA lines. To progress toward clinical translation, we used the knockout mouse model of DTDS that recapitulates human disease, exhibiting parkinsonism features, including tremor, bradykinesia, and premature death. Neonatal intracerebroventricular injection of human SLC6A3 using an adeno-associated virus (AAV) vector provided neuronal expression of human DAT, which ameliorated motor phenotype, life span, and neuronal survival in the substantia nigra and striatum, although off-target neurotoxic effects were seen at higher dosage. These were avoided with stereotactic delivery of AAV2.SLC6A3 gene therapy targeted to the midbrain of adult knockout mice, which rescued both motor phenotype and neurodegeneration, suggesting that targeted AAV gene therapy might be effective for patients with DTDS.
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Affiliation(s)
- Joanne Ng
- Gene Transfer Technology Group, EGA-Institute for Women's Health, University College London, London, WC1E 6HX, UK
- Developmental Neurosciences, Zayed Centre for Research into Rare Disease in Children, GOS-Institute of Child Health, University College London, London, WC1N 1DZ, UK
| | - Serena Barral
- Developmental Neurosciences, Zayed Centre for Research into Rare Disease in Children, GOS-Institute of Child Health, University College London, London, WC1N 1DZ, UK.
| | | | - Gabriele Lignani
- Clinical and Experimental Epilepsy, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Fatma A Erdem
- Developmental Neurosciences, Zayed Centre for Research into Rare Disease in Children, GOS-Institute of Child Health, University College London, London, WC1N 1DZ, UK
- Institute of Pharmacology and Gaston H. Glock Laboratories for Exploratory Drug Research, Centre of Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Rebecca Wallings
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Riccardo Privolizzi
- Gene Transfer Technology Group, EGA-Institute for Women's Health, University College London, London, WC1E 6HX, UK
- Developmental Neurosciences, Zayed Centre for Research into Rare Disease in Children, GOS-Institute of Child Health, University College London, London, WC1N 1DZ, UK
| | - Giada Rossignoli
- Developmental Neurosciences, Zayed Centre for Research into Rare Disease in Children, GOS-Institute of Child Health, University College London, London, WC1N 1DZ, UK
| | - Haya Alrashidi
- Genetics and Genomic Medicine, GOS-Institute of Child Health, University College London, London, WC1N 1EH, UK
| | - Sonja Heasman
- Developmental Neurosciences, Zayed Centre for Research into Rare Disease in Children, GOS-Institute of Child Health, University College London, London, WC1N 1DZ, UK
| | - Esther Meyer
- Developmental Neurosciences, Zayed Centre for Research into Rare Disease in Children, GOS-Institute of Child Health, University College London, London, WC1N 1DZ, UK
| | - Adeline Ngoh
- Developmental Neurosciences, Zayed Centre for Research into Rare Disease in Children, GOS-Institute of Child Health, University College London, London, WC1N 1DZ, UK
| | - Simon Pope
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Rajvinder Karda
- Gene Transfer Technology Group, EGA-Institute for Women's Health, University College London, London, WC1E 6HX, UK
| | - Dany Perocheau
- Gene Transfer Technology Group, EGA-Institute for Women's Health, University College London, London, WC1E 6HX, UK
| | - Julien Baruteau
- Gene Transfer Technology Group, EGA-Institute for Women's Health, University College London, London, WC1E 6HX, UK
- Genetics and Genomic Medicine, GOS-Institute of Child Health, University College London, London, WC1N 1EH, UK
| | - Natalie Suff
- Gene Transfer Technology Group, EGA-Institute for Women's Health, University College London, London, WC1E 6HX, UK
- Department of Women and Children's Health, King's College London, London, WC2R 2LS, UK
| | - Juan Antinao Diaz
- Gene Transfer Technology Group, EGA-Institute for Women's Health, University College London, London, WC1E 6HX, UK
| | - Stephanie Schorge
- Clinical and Experimental Epilepsy, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
- Pharmacology, School of Pharmacy, University College London, London, WC1N 1AX, UK
| | - Jane Vowles
- James Martin Stem Cell Facility, Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE, UK
| | - Lucy R Marshall
- Infection, Immunity, Inflammation, GOS-Institute of Child Health, University College London, London, WC1N 1EH, UK
| | - Sally A Cowley
- James Martin Stem Cell Facility, Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE, UK
| | - Sonja Sucic
- Institute of Pharmacology and Gaston H. Glock Laboratories for Exploratory Drug Research, Centre of Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Michael Freissmuth
- Institute of Pharmacology and Gaston H. Glock Laboratories for Exploratory Drug Research, Centre of Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - John R Counsell
- Developmental Neurosciences, GOS-Institute of Child Health, University College London, London, WC1N 1EH, UK
| | - Richard Wade-Martins
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Simon J R Heales
- Genetics and Genomic Medicine, GOS-Institute of Child Health, University College London, London, WC1N 1EH, UK
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Ahad A Rahim
- Pharmacology, School of Pharmacy, University College London, London, WC1N 1AX, UK
| | - Maximilien Bencze
- Developmental Neurosciences, GOS-Institute of Child Health, University College London, London, WC1N 1EH, UK
- University Paris Est Creteil, INSERM, IMRB, 94000 Creteil, France
| | - Simon N Waddington
- Gene Transfer Technology Group, EGA-Institute for Women's Health, University College London, London, WC1E 6HX, UK.
- Wits/SAMRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, University of the Witwatersrand, 2193 Johannesburg, South Africa
| | - Manju A Kurian
- Developmental Neurosciences, Zayed Centre for Research into Rare Disease in Children, GOS-Institute of Child Health, University College London, London, WC1N 1DZ, UK
- Department of Neurology, Great Ormond Street Hospital for Children, London, WC1N 3JH, UK
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Wainwright L, Hargreaves IP, Georgian AR, Turner C, Dalton RN, Abbott NJ, Heales SJR, Preston JE. CoQ 10 Deficient Endothelial Cell Culture Model for the Investigation of CoQ 10 Blood-Brain Barrier Transport. J Clin Med 2020; 9:jcm9103236. [PMID: 33050406 PMCID: PMC7601674 DOI: 10.3390/jcm9103236] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/02/2020] [Accepted: 10/06/2020] [Indexed: 12/31/2022] Open
Abstract
Primary coenzyme Q10 (CoQ10) deficiency is unique among mitochondrial respiratory chain disorders in that it is potentially treatable if high-dose CoQ10 supplements are given in the early stages of the disease. While supplements improve peripheral abnormalities, neurological symptoms are only partially or temporarily ameliorated. The reasons for this refractory response to CoQ10 supplementation are unclear, however, a contributory factor may be the poor transfer of CoQ10 across the blood-brain barrier (BBB). The aim of this study was to investigate mechanisms of CoQ10 transport across the BBB, using normal and pathophysiological (CoQ10 deficient) cell culture models. The study identifies lipoprotein-associated CoQ10 transcytosis in both directions across the in vitro BBB. Uptake via SR-B1 (Scavenger Receptor) and RAGE (Receptor for Advanced Glycation Endproducts), is matched by efflux via LDLR (Low Density Lipoprotein Receptor) transporters, resulting in no "net" transport across the BBB. In the CoQ10 deficient model, BBB tight junctions were disrupted and CoQ10 "net" transport to the brain side increased. The addition of anti-oxidants did not improve CoQ10 uptake to the brain side. This study is the first to generate in vitro BBB endothelial cell models of CoQ10 deficiency, and the first to identify lipoprotein-associated uptake and efflux mechanisms regulating CoQ10 distribution across the BBB. The results imply that the uptake of exogenous CoQ10 into the brain might be improved by the administration of LDLR inhibitors, or by interventions to stimulate luminal activity of SR-B1 transporters.
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Affiliation(s)
- Luke Wainwright
- UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK;
| | - Iain P. Hargreaves
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London WC1N 3BG, UK;
- Department of Pharmacy and Biomolecular Science, Liverpool John Moores University, Liverpool L3 5UA, UK
| | - Ana R. Georgian
- School of Cancer and Pharmaceutical Sciences, King’s College London, London SE1 9NH, UK; (A.R.G.); (N.J.A.)
| | - Charles Turner
- Evelina London Children’s Hospital, Guy’s and St. Thomas’ NHS Foundation Trust, London SE1 7EH, UK; (C.T.); (R.N.D.)
| | - R. Neil Dalton
- Evelina London Children’s Hospital, Guy’s and St. Thomas’ NHS Foundation Trust, London SE1 7EH, UK; (C.T.); (R.N.D.)
| | - N. Joan Abbott
- School of Cancer and Pharmaceutical Sciences, King’s College London, London SE1 9NH, UK; (A.R.G.); (N.J.A.)
| | - Simon J. R. Heales
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London WC1N 3BG, UK;
- UCL Great Ormond Street Institute of Child Health, University College London, London WC1E 6BT, UK;
| | - Jane E. Preston
- School of Cancer and Pharmaceutical Sciences, King’s College London, London SE1 9NH, UK; (A.R.G.); (N.J.A.)
- Correspondence: ; Tel.: +44-207-848-4881
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Lambert JRA, Howe SJ, Rahim AA, Burke DG, Heales SJR. Inhibition of Mitochondrial Complex I Impairs Release of α-Galactosidase by Jurkat Cells. Int J Mol Sci 2019; 20:E4349. [PMID: 31491876 PMCID: PMC6770804 DOI: 10.3390/ijms20184349] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 09/03/2019] [Indexed: 12/20/2022] Open
Abstract
Fabry disease (FD) is caused by mutations in the GLA gene that encodes lysosomal α-galactosidase-A (α-gal-A). A number of pathogenic mechanisms have been proposed and these include loss of mitochondrial respiratory chain activity. For FD, gene therapy is beginning to be applied as a treatment. In view of the loss of mitochondrial function reported in FD, we have considered here the impact of loss of mitochondrial respiratory chain activity on the ability of a GLA lentiviral vector to increase cellular α-gal-A activity and participate in cross correction. Jurkat cells were used in this study and were exposed to increasing viral copies. Intracellular and extracellular enzyme activities were then determined; this in the presence or absence of the mitochondrial complex I inhibitor, rotenone. The ability of cells to take up released enzyme was also evaluated. Increasing transgene copies was associated with increasing intracellular α-gal-A activity but this was associated with an increase in Km. Release of enzyme and cellular uptake was also demonstrated. However, in the presence of rotenone, enzyme release was inhibited by 37%. Excessive enzyme generation may result in a protein with inferior kinetic properties and a background of compromised mitochondrial function may impair the cross correction process.
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Affiliation(s)
- Jonathan R A Lambert
- Enzyme Unit Great Ormond Street Hospital, London WC1N 3JH, UK.
- University College London Great Ormond Street Institute of Child Health London, London WC1N 1EH, UK.
| | - Steven J Howe
- University College London Great Ormond Street Institute of Child Health London, London WC1N 1EH, UK.
| | - Ahad A Rahim
- University College London School of Pharmacy, University College London, London WC1N 1AX, UK.
| | - Derek G Burke
- Enzyme Unit Great Ormond Street Hospital, London WC1N 3JH, UK.
- University College London Great Ormond Street Institute of Child Health London, London WC1N 1EH, UK.
| | - Simon J R Heales
- Enzyme Unit Great Ormond Street Hospital, London WC1N 3JH, UK.
- University College London Great Ormond Street Institute of Child Health London, London WC1N 1EH, UK.
- Neurometabolic Unit, National Hospital, London WC1N 3BG, UK.
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7
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Chelban V, Wilson MP, Warman Chardon J, Vandrovcova J, Zanetti MN, Zamba‐Papanicolaou E, Efthymiou S, Pope S, Conte MR, Abis G, Liu Y, Tribollet E, Haridy NA, Botía JA, Ryten M, Nicolaou P, Minaidou A, Christodoulou K, Kernohan KD, Eaton A, Osmond M, Ito Y, Bourque P, Jepson JEC, Bello O, Bremner F, Cordivari C, Reilly MM, Foiani M, Heslegrave A, Zetterberg H, Heales SJR, Wood NW, Rothman JE, Boycott KM, Mills PB, Clayton PT, Houlden H. PDXK mutations cause polyneuropathy responsive to pyridoxal 5'-phosphate supplementation. Ann Neurol 2019; 86:225-240. [PMID: 31187503 PMCID: PMC6772106 DOI: 10.1002/ana.25524] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 06/05/2019] [Accepted: 06/07/2019] [Indexed: 12/30/2022]
Abstract
OBJECTIVE To identify disease-causing variants in autosomal recessive axonal polyneuropathy with optic atrophy and provide targeted replacement therapy. METHODS We performed genome-wide sequencing, homozygosity mapping, and segregation analysis for novel disease-causing gene discovery. We used circular dichroism to show secondary structure changes and isothermal titration calorimetry to investigate the impact of variants on adenosine triphosphate (ATP) binding. Pathogenicity was further supported by enzymatic assays and mass spectroscopy on recombinant protein, patient-derived fibroblasts, plasma, and erythrocytes. Response to supplementation was measured with clinical validated rating scales, electrophysiology, and biochemical quantification. RESULTS We identified biallelic mutations in PDXK in 5 individuals from 2 unrelated families with primary axonal polyneuropathy and optic atrophy. The natural history of this disorder suggests that untreated, affected individuals become wheelchair-bound and blind. We identified conformational rearrangement in the mutant enzyme around the ATP-binding pocket. Low PDXK ATP binding resulted in decreased erythrocyte PDXK activity and low pyridoxal 5'-phosphate (PLP) concentrations. We rescued the clinical and biochemical profile with PLP supplementation in 1 family, improvement in power, pain, and fatigue contributing to patients regaining their ability to walk independently during the first year of PLP normalization. INTERPRETATION We show that mutations in PDXK cause autosomal recessive axonal peripheral polyneuropathy leading to disease via reduced PDXK enzymatic activity and low PLP. We show that the biochemical profile can be rescued with PLP supplementation associated with clinical improvement. As B6 is a cofactor in diverse essential biological pathways, our findings may have direct implications for neuropathies of unknown etiology characterized by reduced PLP levels. ANN NEUROL 2019;86:225-240.
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Affiliation(s)
- Viorica Chelban
- Department of Neuromuscular DiseasesUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
- Department of Neurology and NeurosurgeryInstitute of Emergency MedicineChisinauMoldova
| | - Matthew P. Wilson
- Genetics and Genomic MedicineUniversity College London Great Ormond Street Institute of Child HealthLondonUnited Kingdom
| | - Jodi Warman Chardon
- Department of Medicine (Neurology)University of OttawaOttawaOntarioCanada
- Ottawa Hospital Research InstituteOttawaOntarioCanada
- Children's Hospital of Eastern Ontario Research Institute, University of OttawaOttawaOntarioCanada
| | - Jana Vandrovcova
- Department of Neuromuscular DiseasesUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
| | - M. Natalia Zanetti
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
| | - Eleni Zamba‐Papanicolaou
- Cyprus Institute of Neurology and GeneticsNicosiaCyprus
- Cyprus School of Molecular MedicineNicosiaCyprus
| | - Stephanie Efthymiou
- Department of Neuromuscular DiseasesUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
| | - Simon Pope
- Neurometabolic Unit, National Hospital for Neurology and NeurosurgeryLondonUnited Kingdom
| | - Maria R. Conte
- Randall Centre of Cell and Molecular Biophysics, School of Basic and Medical BiosciencesKing's College LondonLondonUnited Kingdom
| | - Giancarlo Abis
- Randall Centre of Cell and Molecular Biophysics, School of Basic and Medical BiosciencesKing's College LondonLondonUnited Kingdom
| | - Yo‐Tsen Liu
- Department of NeurologyNeurological Institute, Taipei Veterans General HospitalTaipeiTaiwan
- National Yang‐Ming University School of MedicineTaipeiTaiwan
- Institute of Brain Science, National Yang‐Ming UniversityTaipeiTaiwan
| | - Eloise Tribollet
- Department of Neuromuscular DiseasesUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
| | - Nourelhoda A. Haridy
- Department of Neuromuscular DiseasesUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
- Department of Neurology and PsychiatryAssiut University Hospital, Faculty of MedicineAsyutEgypt
| | - Juan A. Botía
- Reta Lila Weston Research LaboratoriesUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
- Department of Information and Communications EngineeringUniversity of MurciaMurciaSpain
| | - Mina Ryten
- Reta Lila Weston Research LaboratoriesUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
- Department of Medical & Molecular GeneticsKing's College London, Guy's HospitalLondonUnited Kingdom
| | - Paschalis Nicolaou
- Cyprus Institute of Neurology and GeneticsNicosiaCyprus
- Cyprus School of Molecular MedicineNicosiaCyprus
| | - Anna Minaidou
- Cyprus Institute of Neurology and GeneticsNicosiaCyprus
- Cyprus School of Molecular MedicineNicosiaCyprus
| | - Kyproula Christodoulou
- Cyprus Institute of Neurology and GeneticsNicosiaCyprus
- Cyprus School of Molecular MedicineNicosiaCyprus
| | - Kristin D. Kernohan
- Children's Hospital of Eastern Ontario Research Institute, University of OttawaOttawaOntarioCanada
- Newborn Screening Ontario, Children's Hospital of Eastern OntarioOttawaOntarioCanada
| | - Alison Eaton
- Children's Hospital of Eastern Ontario Research Institute, University of OttawaOttawaOntarioCanada
| | - Matthew Osmond
- Children's Hospital of Eastern Ontario Research Institute, University of OttawaOttawaOntarioCanada
| | - Yoko Ito
- Children's Hospital of Eastern Ontario Research Institute, University of OttawaOttawaOntarioCanada
| | - Pierre Bourque
- Department of Medicine (Neurology)University of OttawaOttawaOntarioCanada
- Ottawa Hospital Research InstituteOttawaOntarioCanada
| | - James E. C. Jepson
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
| | - Oscar Bello
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
| | - Fion Bremner
- Neuro‐ophthalmology DepartmentNational Hospital for Neurology and NeurosurgeryLondonUnited Kingdom
| | - Carla Cordivari
- Clinical Neurophysiology DepartmentNational Hospital for Neurology and NeurosurgeryLondonUnited Kingdom
| | - Mary M. Reilly
- Department of Neuromuscular DiseasesUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
| | - Martha Foiani
- Clinical Neurophysiology DepartmentNational Hospital for Neurology and NeurosurgeryLondonUnited Kingdom
- Department of Neurodegenerative DiseaseUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
| | - Amanda Heslegrave
- Department of Neurodegenerative DiseaseUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
- UK Dementia Research Institute at University College LondonLondonUnited Kingdom
| | - Henrik Zetterberg
- Department of Neurodegenerative DiseaseUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
- UK Dementia Research Institute at University College LondonLondonUnited Kingdom
- Clinical Neurochemistry LaboratorySahlgrenska University HospitalMölndalSweden
- Department of Psychiatry and NeurochemistryInstitute of Neuroscience and Physiology, Sahlgrenska Academy at University of GothenburgMölndalSweden
| | - Simon J. R. Heales
- Neurometabolic Unit, National Hospital for Neurology and NeurosurgeryLondonUnited Kingdom
| | - Nicholas W. Wood
- Department of Neuromuscular DiseasesUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
- Neurogenetics LaboratoryNational Hospital for Neurology and NeurosurgeryLondonUnited Kingdom
| | - James E. Rothman
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
- Department of Cell BiologyYale School of MedicineNew HavenCT
| | - Kym M. Boycott
- Children's Hospital of Eastern Ontario Research Institute, University of OttawaOttawaOntarioCanada
| | - Philippa B. Mills
- Genetics and Genomic MedicineUniversity College London Great Ormond Street Institute of Child HealthLondonUnited Kingdom
| | - Peter T. Clayton
- Genetics and Genomic MedicineUniversity College London Great Ormond Street Institute of Child HealthLondonUnited Kingdom
| | - Henry Houlden
- Department of Neuromuscular DiseasesUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
- Neurogenetics LaboratoryNational Hospital for Neurology and NeurosurgeryLondonUnited Kingdom
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Papandreou A, Rahman S, Fratter C, Ng J, Meyer E, Carr LJ, Champion M, Clarke A, Gissen P, Hemingway C, Hussain N, Jayawant S, King MD, Lynch BJ, Mewasingh L, Patel J, Prabhakar P, Neergheen V, Pope S, Heales SJR, Poulton J, Kurian MA. Correction to: Spectrum of movement disorders and neurotransmitter abnormalities in paediatric POLG disease. J Inherit Metab Dis 2018; 41:1299-1301. [PMID: 30456588 PMCID: PMC6828478 DOI: 10.1007/s10545-018-0247-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Due to a typesetting error the wrong Table 2 was used. The correct Table 2 is shown here.
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Affiliation(s)
- A Papandreou
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, 30 Guildford Street, London, WC1N 1EH, UK
- Department of Neurology, Great Ormond Street Hospital for Children, London, UK
- Genetics and Genomics Medicine Programme, UCL Great Ormond Street Institute of Child Health, London, UK
| | - S Rahman
- Mitochondrial Research Group, Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Metabolic Department, Great Ormond Street Hospital for Children, London, UK
| | - C Fratter
- Oxford Medical Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - J Ng
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, 30 Guildford Street, London, WC1N 1EH, UK
| | - E Meyer
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, 30 Guildford Street, London, WC1N 1EH, UK
| | - L J Carr
- Department of Neurology, Great Ormond Street Hospital for Children, London, UK
| | - M Champion
- Department of Inherited Metabolic Disease, Evelina London Children's Hospital, London, UK
| | - A Clarke
- Paediatric Neurology Department, St George's University Hospital, London, UK
| | - P Gissen
- Genetics and Genomics Medicine Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Metabolic Department, Great Ormond Street Hospital for Children, London, UK
- UCL-MRC Laboratory of Molecular Cell Biology, London, UK
| | - C Hemingway
- Department of Neurology, Great Ormond Street Hospital for Children, London, UK
| | - N Hussain
- Department of Paediatric Neurology, University Hospital of Leicester, Leicester, UK
| | - S Jayawant
- Department of Paediatric Neurology, John Radcliffe Hospital, Oxford, UK
| | - M D King
- Department of Paediatric Neurology and Clinical Neurophysiology, Children's University Hospital, Temple Street, Dublin, Ireland
| | - B J Lynch
- Department of Neurology and Clinical Neurophysiology, Children's University Hospital, Temple Street, Dublin, Ireland
| | - L Mewasingh
- Department of Paediatric Neurology, Imperial College Healthcare NHS Trust, London, UK
| | - J Patel
- Department of Paediatric Neurology, Bristol Royal Hospital for Children, Bristol, UK
| | - P Prabhakar
- Department of Neurology, Great Ormond Street Hospital for Children, London, UK
| | - V Neergheen
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK
| | - S Pope
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK
| | - S J R Heales
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK
- Department of Paediatric Laboratory Medicine, Great Ormond Street Hospital for Children, London, UK
| | - J Poulton
- Nuffield Department of Women's and Reproductive Health, University of Oxford, The Women's Centre, Oxford, UK
| | - Manju A Kurian
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, 30 Guildford Street, London, WC1N 1EH, UK.
- Department of Neurology, Great Ormond Street Hospital for Children, London, UK.
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9
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Papandreou A, Rahman S, Fratter C, Ng J, Meyer E, Carr LJ, Champion M, Clarke A, Gissen P, Hemingway C, Hussain N, Jayawant S, King MD, Lynch BJ, Mewasingh L, Patel J, Prabhakar P, Neergheen V, Pope S, Heales SJR, Poulton J, Kurian MA. Spectrum of movement disorders and neurotransmitter abnormalities in paediatric POLG disease. J Inherit Metab Dis 2018; 41:1275-1283. [PMID: 30167885 PMCID: PMC6326959 DOI: 10.1007/s10545-018-0227-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 06/15/2018] [Accepted: 06/26/2018] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To describe the spectrum of movement disorders and cerebrospinal fluid (CSF) neurotransmitter profiles in paediatric patients with POLG disease. METHODS We identified children with genetically confirmed POLG disease, in whom CSF neurotransmitter analysis had been undertaken. Clinical data were collected retrospectively. CSF neurotransmitter levels were compared to both standardised age-related reference ranges and to non-POLG patients presenting with status epilepticus. RESULTS Forty-one patients with POLG disease were identified. Almost 50% of the patients had documented evidence of a movement disorder, including non-epileptic myoclonus, choreoathetosis and ataxia. CSF neurotransmitter analysis was undertaken in 15 cases and abnormalities were seen in the majority (87%) of cases tested. In many patients, distinctive patterns were evident, including raised neopterin, homovanillic acid and 5-hydroxyindoleacetic acid levels. CONCLUSIONS Children with POLG mutations can manifest with a wide spectrum of abnormal movements, which are often prominent features of the clinical syndrome. Underlying pathophysiology is probably multifactorial, and aberrant monoamine metabolism is likely to play a role.
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Affiliation(s)
- A Papandreou
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, 30 Guildford Street, London, WC1N 1EH, UK
- Department of Neurology, Great Ormond Street Hospital for Children, London, UK
- Genetics and Genomics Medicine Programme, UCL Great Ormond Street Institute of Child Health, London, UK
| | - S Rahman
- Mitochondrial Research Group, Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Metabolic Department, Great Ormond Street Hospital for Children, London, UK
| | - C Fratter
- Oxford Medical Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - J Ng
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, 30 Guildford Street, London, WC1N 1EH, UK
| | - E Meyer
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, 30 Guildford Street, London, WC1N 1EH, UK
| | - L J Carr
- Department of Neurology, Great Ormond Street Hospital for Children, London, UK
| | - M Champion
- Department of Inherited Metabolic Disease, Evelina London Children's Hospital, London, UK
| | - A Clarke
- Paediatric Neurology Department, St George's University Hospital, London, UK
| | - P Gissen
- Genetics and Genomics Medicine Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Metabolic Department, Great Ormond Street Hospital for Children, London, UK
- UCL-MRC Laboratory of Molecular Cell Biology, London, UK
| | - C Hemingway
- Department of Neurology, Great Ormond Street Hospital for Children, London, UK
| | - N Hussain
- Department of Paediatric Neurology, University Hospital of Leicester, Leicester, UK
| | - S Jayawant
- Department of Paediatric Neurology, John Radcliffe Hospital, Oxford, UK
| | - M D King
- Department of Paediatric Neurology and Clinical Neurophysiology, Children's University Hospital, Temple Street, Dublin, Ireland
| | - B J Lynch
- Department of Neurology and Clinical Neurophysiology, Children's University Hospital, Temple Street, Dublin, Ireland
| | - L Mewasingh
- Department of Paediatric Neurology, Imperial College Healthcare NHS Trust, London, UK
| | - J Patel
- Department of Paediatric Neurology, Bristol Royal Hospital for Children, Bristol, UK
| | - P Prabhakar
- Department of Neurology, Great Ormond Street Hospital for Children, London, UK
| | - V Neergheen
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK
| | - S Pope
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK
| | - S J R Heales
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK
- Department of Paediatric Laboratory Medicine, Great Ormond Street Hospital for Children, London, UK
| | - J Poulton
- Nuffield Department of Women's and Reproductive Health, University of Oxford, The Women's Centre, Oxford, UK
| | - Manju A Kurian
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, 30 Guildford Street, London, WC1N 1EH, UK.
- Department of Neurology, Great Ormond Street Hospital for Children, London, UK.
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10
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Augustin K, Khabbush A, Williams S, Eaton S, Orford M, Cross JH, Heales SJR, Walker MC, Williams RSB. Mechanisms of action for the medium-chain triglyceride ketogenic diet in neurological and metabolic disorders. Lancet Neurol 2017; 17:84-93. [PMID: 29263011 DOI: 10.1016/s1474-4422(17)30408-8] [Citation(s) in RCA: 245] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 11/03/2017] [Accepted: 11/20/2017] [Indexed: 12/16/2022]
Abstract
High-fat, low-carbohydrate diets, known as ketogenic diets, have been used as a non-pharmacological treatment for refractory epilepsy. A key mechanism of this treatment is thought to be the generation of ketones, which provide brain cells (neurons and astrocytes) with an energy source that is more efficient than glucose, resulting in beneficial downstream metabolic changes, such as increasing adenosine levels, which might have effects on seizure control. However, some studies have challenged the central role of ketones because medium-chain fatty acids, which are part of a commonly used variation of the diet (the medium-chain triglyceride ketogenic diet), have been shown to directly inhibit AMPA receptors (glutamate receptors), and to change cell energetics through mitochondrial biogenesis. Through these mechanisms, medium-chain fatty acids rather than ketones are likely to block seizure onset and raise seizure threshold. The mechanisms underlying the ketogenic diet might also have roles in other disorders, such as preventing neurodegeneration in Alzheimer's disease, the proliferation and spread of cancer, and insulin resistance in type 2 diabetes. Analysing medium-chain fatty acids in future ketogenic diet studies will provide further insights into their importance in modified forms of the diet. Moreover, the results of these studies could facilitate the development of new pharmacological and dietary therapies for epilepsy and other disorders.
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Affiliation(s)
- Katrin Augustin
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, UK
| | - Aziza Khabbush
- UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Sophie Williams
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK
| | - Simon Eaton
- UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Michael Orford
- UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - J Helen Cross
- Neurosciences Unit, UCL Institute of Child Health, University College London, London, UK
| | - Simon J R Heales
- UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Matthew C Walker
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK
| | - Robin S B Williams
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, UK.
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Wilson MP, Footitt EJ, Papandreou A, Uudelepp ML, Pressler R, Stevenson DC, Gabriel C, McSweeney M, Baggot M, Burke D, Stödberg T, Riney K, Schiff M, Heales SJR, Mills KA, Gissen P, Clayton PT, Mills PB. An LC-MS/MS-Based Method for the Quantification of Pyridox(am)ine 5'-Phosphate Oxidase Activity in Dried Blood Spots from Patients with Epilepsy. Anal Chem 2017; 89:8892-8900. [PMID: 28782931 PMCID: PMC5588098 DOI: 10.1021/acs.analchem.7b01358] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We report the development of a rapid, simple, and robust LC-MS/MS-based enzyme assay using dried blood spots (DBS) for the diagnosis of pyridox(am)ine 5'-phosphate oxidase (PNPO) deficiency (OMIM 610090). PNPO deficiency leads to potentially fatal early infantile epileptic encephalopathy, severe developmental delay, and other features of neurological dysfunction. However, upon prompt treatment with high doses of vitamin B6, affected patients can have a normal developmental outcome. Prognosis of these patients is therefore reliant upon a rapid diagnosis. PNPO activity was quantified by measuring pyridoxal 5'-phosphate (PLP) concentrations in a DBS before and after a 30 min incubation with pyridoxine 5'-phosphate (PNP). Samples from 18 PNPO deficient patients (1 day-25 years), 13 children with other seizure disorders receiving B6 supplementation (1 month-16 years), and 37 child hospital controls (5 days-15 years) were analyzed. DBS from the PNPO-deficient samples showed enzyme activity levels lower than all samples from these two other groups as well as seven adult controls; no false positives or negatives were identified. The method was fully validated and is suitable for translation into the clinical diagnostic arena.
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Affiliation(s)
- Matthew P Wilson
- Genetics and Genomic Medicine, UCL GOS Institute of Child Health , 30 Guilford Street, London WC1N 1EH, United Kingdom
| | | | - Apostolos Papandreou
- Genetics and Genomic Medicine, UCL GOS Institute of Child Health , 30 Guilford Street, London WC1N 1EH, United Kingdom
| | - Mari-Liis Uudelepp
- Genetics and Genomic Medicine, UCL GOS Institute of Child Health , 30 Guilford Street, London WC1N 1EH, United Kingdom
| | | | | | | | | | | | | | - Tommy Stödberg
- Neuropediatric Unit, Karolinska University Hospital , Stockholm SE-171 76, Sweden
| | - Kate Riney
- Neurosciences Unit, The Lady Cilento Children's Hospital , 501 Stanley Street, South Brisbane, Queensland 4101, Australia
| | - Manuel Schiff
- Reference Center for Inborn Errors of Metabolism, Robert Debré University Hospital , APHP, Paris 75019, France
| | - Simon J R Heales
- Genetics and Genomic Medicine, UCL GOS Institute of Child Health , 30 Guilford Street, London WC1N 1EH, United Kingdom.,Neurometabolic Unit, National Hospital for Neurology and Neurosurgery , Queen Square, London WC1N 3BG, United Kingdom
| | - Kevin A Mills
- Genetics and Genomic Medicine, UCL GOS Institute of Child Health , 30 Guilford Street, London WC1N 1EH, United Kingdom
| | - Paul Gissen
- Genetics and Genomic Medicine, UCL GOS Institute of Child Health , 30 Guilford Street, London WC1N 1EH, United Kingdom
| | - Peter T Clayton
- Genetics and Genomic Medicine, UCL GOS Institute of Child Health , 30 Guilford Street, London WC1N 1EH, United Kingdom
| | - Philippa B Mills
- Genetics and Genomic Medicine, UCL GOS Institute of Child Health , 30 Guilford Street, London WC1N 1EH, United Kingdom
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Khabbush A, Orford M, Tsai YC, Rutherford T, O'Donnell M, Eaton S, Heales SJR. Neuronal decanoic acid oxidation is markedly lower than that of octanoic acid: A mechanistic insight into the medium-chain triglyceride ketogenic diet. Epilepsia 2017; 58:1423-1429. [PMID: 28682459 DOI: 10.1111/epi.13833] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2017] [Indexed: 12/16/2022]
Abstract
OBJECTIVE The medium-chain triglyceride (MCT) ketogenic diet contains both octanoic (C8) and decanoic (C10) acids. The diet is an effective treatment for pharmacoresistant epilepsy. Although the exact mechanism for its efficacy is not known, it is emerging that C10, but not C8, interacts with targets that can explain antiseizure effects, for example, peroxisome proliferator-activated receptor-γ (eliciting mitochondrial biogenesis and increased antioxidant status) and the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor. For such effects to occur, significant concentrations of C10 are likely to be required in the brain. METHODS To investigate how this might occur, we measured the β-oxidation rate of 13 C-labeled C8 and C10 in neuronal SH-SY5Y cells using isotope-ratio mass spectrometry. The effects of carnitine palmitoyltransferase I (CPT1) inhibition, with the CPT1 inhibitor etomoxir, on C8 and C10 β-oxidation were also investigated. RESULTS Both fatty acids were catabolized, as judged by 13 CO2 release. However, C10 was β-oxidized at a significantly lower rate, 20% that of C8. This difference was explained by a clear dependence of C10 on CPT1 activity, which is low in neurons, whereas 66% of C8 β-oxidation was independent of CPT1. In addition, C10 β-oxidation was decreased further in the presence of C8. SIGNIFICANCE It is concluded that, because CPT1 is poorly expressed in the brain, C10 is relatively spared from β-oxidation and can accumulate. This is further facilitated by the presence of C8 in the MCT ketogenic diet, which has a sparing effect upon C10 β-oxidation.
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Affiliation(s)
- Aziza Khabbush
- Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Michael Orford
- Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Yi-Chen Tsai
- Division of Colorectal Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | | | | | - Simon Eaton
- Paediatric Surgery, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Simon J R Heales
- Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
- Chemical Pathology, Great Ormond Street for Children Hospital NHS Foundation Trust, London, United Kingdom
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, London, United Kingdom
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13
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Schoeler NE, Bell G, Yuen A, Kapelner AD, Heales SJR, Cross JH, Sisodiya S. An examination of biochemical parameters and their association with response to ketogenic dietary therapies. Epilepsia 2017; 58:893-900. [PMID: 28369834 DOI: 10.1111/epi.13729] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2017] [Indexed: 12/25/2022]
Abstract
OBJECTIVE In the absence of specific metabolic disorders, accurate predictors of response to ketogenic dietary therapies (KDTs) for treating epilepsy are largely unknown. We hypothesized that specific biochemical parameters would be associated with the effectiveness of KDT in humans with epilepsy. The parameters tested were β-hydroxybutyrate, acetoacetate, nonesterified fatty acids, free and acylcarnitine profile, glucose, and glucose-ketone index (GKI). METHODS Biochemical results from routine blood tests conducted at baseline prior to initiation of KDT and at 3-month follow-up were obtained from 13 adults and 215 children with KDT response data from participating centers. One hundred thirty-two (57%) of 228 participants had some data at both baseline and 3 months; 52 (23%) of 228 had data only at baseline; 22 (10%) of 228 had data only at 3 months; and 22 (10%) of 228 had no data. KDT response was defined as ≥50% seizure reduction at 3-month follow-up. RESULTS Acetyl carnitine at baseline was significantly higher in responders (p < 0.007). It was not associated with response at 3-month follow-up. There was a trend for higher levels of free carnitine and other acylcarnitine esters at baseline and at 3-month follow-up in KDT responders. There was also a trend for greater differences in levels of propionyl carnitine and in β-hydroxybutyrate measured at baseline and 3-month follow-up in KDT responders. No other biochemical parameters were associated with response at any time point. SIGNIFICANCE Our finding that certain carnitine fractions, in particular baseline acetyl carnitine, are positively associated with greater efficacy of KDT is consistent with the theory that alterations in energy metabolism may play a role in the mechanisms of action of KDT.
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Affiliation(s)
- Natasha E Schoeler
- UCL Great Ormond Street Institute of Child Health, London, United Kingdom.,Department of Clinical and Experimental Epilepsy, NIHR University College London Hospitals Biomedical Research Centre, UCL Institute of Neurology, London, United Kingdom
| | - Gail Bell
- Epilepsy Society, Chalfont St Peter, United Kingdom
| | - Alan Yuen
- Epilepsy Society, Chalfont St Peter, United Kingdom
| | - Adam D Kapelner
- Department of Mathematics, Queens College, The City University of New York (CUNY), New York, New York, U.S.A
| | - Simon J R Heales
- Genetics and Genomic Medicine, UCL Institute of Child Health, London, United Kingdom.,Chemical Pathology, Great Ormond Street Hospital for Children, London, United Kingdom.,Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - J Helen Cross
- UCL Great Ormond Street Institute of Child Health, London, United Kingdom.,Great Ormond Street Hospital for Children, London, United Kingdom.,Young Epilepsy, Lingfield, United Kingdom
| | - Sanjay Sisodiya
- Department of Clinical and Experimental Epilepsy, NIHR University College London Hospitals Biomedical Research Centre, UCL Institute of Neurology, London, United Kingdom.,Epilepsy Society, Chalfont St Peter, United Kingdom
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14
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Kanabus M, Fassone E, Hughes SD, Bilooei SF, Rutherford T, Donnell MO, Heales SJR, Rahman S. The pleiotropic effects of decanoic acid treatment on mitochondrial function in fibroblasts from patients with complex I deficient Leigh syndrome. J Inherit Metab Dis 2016; 39:415-426. [PMID: 27080638 PMCID: PMC4851692 DOI: 10.1007/s10545-016-9930-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 03/10/2016] [Accepted: 03/16/2016] [Indexed: 11/07/2022]
Abstract
There is growing interest in the use of the ketogenic diet (KD) to treat inherited metabolic diseases including mitochondrial disorders. However, neither the mechanism whereby the diet may be working, nor if it could benefit all patients with mitochondrial disease, is known. This study focusses on decanoic acid (C10), a component of the medium chain triglyceride KD, and a ligand for the nuclear receptor PPAR-γ known to be involved in mitochondrial biogenesis. The effects of C10 were investigated in primary fibroblasts from a cohort of patients with Leigh syndrome (LS) caused by nuclear-encoded defects of respiratory chain complex I, using mitochondrial respiratory chain enzyme assays, gene expression microarray, qPCR and flow cytometry. Treatment with C10 increased citrate synthase activity, a marker of cellular mitochondrial content, in 50 % of fibroblasts obtained from individuals diagnosed with LS in a PPAR-γ-mediated manner. Gene expression analysis and qPCR studies suggested that treating cells with C10 supports fatty acid metabolism, through increasing ACADVL and CPT1 expression, whilst downregulating genes involved in glucose metabolism (PDK3, PDK4). PCK2, involved in blocking glucose metabolism, was upregulated, as was CAT, encoding catalase. Moreover, treatment with C10 also decreased oxidative stress in complex I deficient (rotenone treated) cells. However, since not all cells from subjects with LS appeared to respond to C10, prior cellular testing in vitro could be employed as a means for selecting individuals for subsequent clinical studies involving C10 preparations.
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Affiliation(s)
- Marta Kanabus
- Genetics and Genomic Medicine, UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, UK
| | - Elisa Fassone
- Genetics and Genomic Medicine, UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, UK
| | - Sean David Hughes
- Genetics and Genomic Medicine, UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, UK
- Chemical Pathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, WC1N 3JH, UK
| | - Sara Farahi Bilooei
- Genetics and Genomic Medicine, UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, UK
| | | | | | - Simon J R Heales
- Genetics and Genomic Medicine, UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, UK
- Chemical Pathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, WC1N 3JH, UK
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, London, WC1N 3BG, UK
| | - Shamima Rahman
- Genetics and Genomic Medicine, UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, UK.
- Metabolic Department, Great Ormond Street Hospital Foundation Trust, London, WC1N 3JH, UK.
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15
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16
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Montioli R, Paiardini A, Kurian MA, Dindo M, Rossignoli G, Heales SJR, Pope S, Voltattorni CB, Bertoldi M. The novel R347g pathogenic mutation of aromatic amino acid decarboxylase provides additional molecular insights into enzyme catalysis and deficiency. Biochim Biophys Acta 2016; 1864:676-682. [PMID: 26994895 DOI: 10.1016/j.bbapap.2016.03.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 03/15/2016] [Accepted: 03/15/2016] [Indexed: 10/22/2022]
Abstract
We report here a clinical case of a patient with a novel mutation (Arg347→Gly) in the gene encoding aromatic amino acid decarboxylase (AADC) that is associated with AADC deficiency. The variant R347G in the purified recombinant form exhibits, similarly to the pathogenic mutation R347Q previously studied, a 475-fold drop of kcat compared to the wild-type enzyme. In attempting to unravel the reason(s) for this catalytic defect, we have carried out bioinformatics analyses of the crystal structure of AADC-carbidopa complex with the modelled catalytic loop (residues 328-339). Arg347 appears to interact with Phe103, as well as with both Leu333 and Asp345. We have then prepared and characterized the artificial F103L, R347K and D345A mutants. F103L, D345A and R347K exhibit about 13-, 97-, and 345-fold kcat decrease compared to the wild-type AADC, respectively. However, unlike F103L, the R347G, R347K and R347Q mutants as well as the D345A variant appear to be more defective in catalysis than in protein folding. Moreover, the latter mutants, unlike the wild-type protein and the F103L variant, share a peculiar binding mode of dopa methyl ester consisting of formation of a quinonoid intermediate. This finding strongly suggests that their catalytic defects are mainly due to a misplacement of the substrate at the active site. Taken together, our results highlight the importance of the Arg347-Leu333-Asp345 hydrogen-bonds network in the catalysis of AADC and reveal the molecular basis for the pathogenicity of the variants R347. Following the above results, a therapeutic treatment for patients bearing the mutation R347G is proposed.
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Affiliation(s)
- Riccardo Montioli
- Department of Neurosciences, Biomedicine and Movement, University of Verona, Verona, Italy
| | - Alessandro Paiardini
- Department of Biology and Biotechnology "Charles Darwin", La Sapienza University of Roma, Roma, Italy
| | - Manju A Kurian
- Developmental Neurosciences, UCL-Institute of Child Health, London, UK; Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Mirco Dindo
- Department of Neurosciences, Biomedicine and Movement, University of Verona, Verona, Italy
| | - Giada Rossignoli
- Department of Neurosciences, Biomedicine and Movement, University of Verona, Verona, Italy
| | - Simon J R Heales
- Clinical Chemistry, Great Ormond Street Hospital, London, UK; Neurometabolic Unit, National Hospital of Neurology and Neurosurgery, UK
| | - Simon Pope
- Neurometabolic Unit, National Hospital of Neurology and Neurosurgery, UK
| | | | - Mariarita Bertoldi
- Department of Neurosciences, Biomedicine and Movement, University of Verona, Verona, Italy.
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17
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Bowron A, Honeychurch J, Williams M, Tsai-Goodman B, Clayton N, Jones L, Shortland GJ, Qureshi SA, Heales SJR, Steward CG. Erratum to: Barth syndrome without tetralinoleoyl cardiolipin deficiency: a possible ameliorated phenotype. J Inherit Metab Dis 2016; 39:151. [PMID: 26373950 PMCID: PMC4969951 DOI: 10.1007/s10545-015-9891-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Ann Bowron
- Department of Clinical Biochemistry, University Hospitals Bristol NHS Trust, Bristol, BS2 8HW, UK.
- NHS Barth Syndrome Service, Bristol Royal Hospital for Children, University Hospitals Bristol NHS Trust, Bristol, BS2 8BJ, UK.
- School of Cellular & Molecular Medicine, School of Medical Sciences, University Walk, Bristol, BS8 1TD, UK.
| | - Julie Honeychurch
- Bristol Genetics Laboratory, North Bristol NHS Trust, Bristol, BS10 5NB, UK
| | - Maggie Williams
- Bristol Genetics Laboratory, North Bristol NHS Trust, Bristol, BS10 5NB, UK
| | - Beverley Tsai-Goodman
- NHS Barth Syndrome Service, Bristol Royal Hospital for Children, University Hospitals Bristol NHS Trust, Bristol, BS2 8BJ, UK
- Department of Paediatric Cardiology, Bristol Royal Hospital for Children, University Hospitals Bristol NHS Trust, Bristol, BS2 8BJ, UK
| | - Nicol Clayton
- NHS Barth Syndrome Service, Bristol Royal Hospital for Children, University Hospitals Bristol NHS Trust, Bristol, BS2 8BJ, UK
| | - Lucy Jones
- NHS Barth Syndrome Service, Bristol Royal Hospital for Children, University Hospitals Bristol NHS Trust, Bristol, BS2 8BJ, UK
| | - Graham J Shortland
- Department of Metabolic Disease, University Hospitals Wales, Cardiff, CF14 4XW, UK
| | - Shakeel A Qureshi
- Department of Paediatric Cardiology, Evelina Children's Hospital, Guy's and St Thomas' NHS Foundation Trust, London, SE1 7EH, UK
| | - Simon J R Heales
- Department of Chemical Pathology, Great Ormond Street Hospital NHS Foundation Trust, London, WC1N 3JH, UK
- University College London Institute of Child Health, London, WC1N 1EH, UK
| | - Colin G Steward
- NHS Barth Syndrome Service, Bristol Royal Hospital for Children, University Hospitals Bristol NHS Trust, Bristol, BS2 8BJ, UK
- School of Cellular & Molecular Medicine, School of Medical Sciences, University Walk, Bristol, BS8 1TD, UK
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18
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Bowron A, Honeychurch J, Williams M, Tsai-Goodman B, Clayton N, Jones L, Shortland GJ, Qureshi SA, Heales SJR, Steward CG. Barth syndrome without tetralinoleoyl cardiolipin deficiency: a possible ameliorated phenotype. J Inherit Metab Dis 2015; 38:279-86. [PMID: 25112388 PMCID: PMC4341014 DOI: 10.1007/s10545-014-9747-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 07/08/2014] [Accepted: 07/15/2014] [Indexed: 12/01/2022]
Abstract
Barth syndrome (BTHS) is an X-linked disorder characterised by cardiac and skeletal myopathy, growth delay, neutropenia and 3-methylglutaconic aciduria (3-MGCA). Patients have TAZ gene mutations which affect metabolism of cardiolipin, resulting in low tetralinoleoyl cardiolipin (CL(4)), an increase in its precursor, monolysocardiolipin (MLCL), and an increased MLCL/CL(4) ratio. During development of a diagnostic service for BTHS, leukocyte CL(4) was measured in 156 controls and 34 patients with genetically confirmed BTHS. A sub-group of seven subjects from three unrelated families was identified with leukocyte CL(4) concentrations within the control range. This had led to initial false negative disease detection in two of these patients. MLCL/CL(4) in this subgroup was lower than in other BTHS patients but higher than controls, with no overlap between the groups. TAZ gene mutations in these families are all predicted to be pathological. This report describes the clinical histories of these seven individuals with an atypical phenotype: some features were typical of BTHS (five have had cardiomyopathy, one family has a history of male infant deaths, three have growth delay and five have 3-MGCA) but none has persistent neutropenia, five have excellent exercise tolerance and two adults are asymptomatic. This report also emphasises the importance of measurement of MLCL/CL(4) ratio rather than CL(4) alone in the biochemical diagnosis of the BTHS.
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Affiliation(s)
- Ann Bowron
- Department of Clinical Biochemistry, University Hospitals Bristol NHS Trust, Bristol, BS2 8HW, UK,
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19
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Abstract
Coenzyme Q10 (CoQ10) deficiency appears to have a particularly heterogeneous clinical presentation. However, there appear to be 5 recognisable clinical phenotypes: encephalomyopathy, severe infantile multisystemic disease, nephropathy, cerebellar ataxia, and isolated myopathy. However, although useful, clinical symptoms alone are insufficient for the definitive diagnosis of CoQ10 deficiency which relies upon biochemical assessment of tissue CoQ10 status. In this article, we review the biochemical methods used in the diagnosis of human CoQ10 deficiency and indicate the most appropriate tissues for this evaluation.
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Affiliation(s)
- Delia Yubero
- Clinical Biochemistry Department, Hospital Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain
| | - Raquel Montero
- Clinical Biochemistry Department, Hospital Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain
| | - Rafael Artuch
- Clinical Biochemistry Department, Hospital Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain
| | - John M Land
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK
| | - Simon J R Heales
- Chemical Pathology, Great Ormond Street Childrens Hospital, London, UK
| | - Iain P Hargreaves
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK
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20
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Hansen FH, Skjørringe T, Yasmeen S, Arends NV, Sahai MA, Erreger K, Andreassen TF, Holy M, Hamilton PJ, Neergheen V, Karlsborg M, Newman AH, Pope S, Heales SJR, Friberg L, Law I, Pinborg LH, Sitte HH, Loland C, Shi L, Weinstein H, Galli A, Hjermind LE, Møller LB, Gether U. Missense dopamine transporter mutations associate with adult parkinsonism and ADHD. J Clin Invest 2014; 124:3107-20. [PMID: 24911152 DOI: 10.1172/jci73778] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 04/24/2014] [Indexed: 11/17/2022] Open
Abstract
Parkinsonism and attention deficit hyperactivity disorder (ADHD) are widespread brain disorders that involve disturbances of dopaminergic signaling. The sodium-coupled dopamine transporter (DAT) controls dopamine homeostasis, but its contribution to disease remains poorly understood. Here, we analyzed a cohort of patients with atypical movement disorder and identified 2 DAT coding variants, DAT-Ile312Phe and a presumed de novo mutant DAT-Asp421Asn, in an adult male with early-onset parkinsonism and ADHD. According to DAT single-photon emission computed tomography (DAT-SPECT) scans and a fluoro-deoxy-glucose-PET/MRI (FDG-PET/MRI) scan, the patient suffered from progressive dopaminergic neurodegeneration. In heterologous cells, both DAT variants exhibited markedly reduced dopamine uptake capacity but preserved membrane targeting, consistent with impaired catalytic activity. Computational simulations and uptake experiments suggested that the disrupted function of the DAT-Asp421Asn mutant is the result of compromised sodium binding, in agreement with Asp421 coordinating sodium at the second sodium site. For DAT-Asp421Asn, substrate efflux experiments revealed a constitutive, anomalous efflux of dopamine, and electrophysiological analyses identified a large cation leak that might further perturb dopaminergic neurotransmission. Our results link specific DAT missense mutations to neurodegenerative early-onset parkinsonism. Moreover, the neuropsychiatric comorbidity provides additional support for the idea that DAT missense mutations are an ADHD risk factor and suggests that complex DAT genotype and phenotype correlations contribute to different dopaminergic pathologies.
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21
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Duberley KE, Heales SJR, Abramov AY, Chalasani A, Land JM, Rahman S, Hargreaves IP. Effect of Coenzyme Q10 supplementation on mitochondrial electron transport chain activity and mitochondrial oxidative stress in Coenzyme Q10 deficient human neuronal cells. Int J Biochem Cell Biol 2014; 50:60-3. [PMID: 24534273 DOI: 10.1016/j.biocel.2014.02.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 01/28/2014] [Accepted: 02/07/2014] [Indexed: 10/25/2022]
Abstract
Primary Coenzyme Q10 (CoQ10) deficiency is an autosomal recessive disorder with a heterogeneous clinical presentation. Common presenting features include both muscle and neurological dysfunction. Muscle abnormalities can improve, both clinically and biochemically following CoQ10 supplementation, however neurological symptoms are only partially ameliorated. At present, the reasons for the refractory nature of the neurological dysfunction remain unknown. In order to investigate this at the biochemical level we evaluated the effect of CoQ10 treatment upon a previously established neuronal cell model of CoQ10 deficiency. This model was established by treatment of human SH-SY5Y neuronal cells with 1 mM para-aminobenzoic acid (PABA) which induced a 54% decrease in cellular CoQ10 status. CoQ10 treatment (2.5 μM) for 5 days significantly (p<0.0005) decreased the level of mitochondrial superoxide in the CoQ10 deficient neurons. In addition, CoQ10 treatment (5 μM) restored mitochondrial membrane potential to 90% of the control level. However, CoQ10 treatment (10 μM) was only partially effective at restoring mitochondrial electron transport chain (ETC) enzyme activities. ETC complexes II/III activity was significantly (p<0.05) increased to 82.5% of control levels. ETC complexes I and IV activities were restored to 71.1% and 77.7%, respectively of control levels. In conclusion, the results of this study have indicated that although mitochondrial oxidative stress can be attenuated in CoQ10 deficient neurons following CoQ10 supplementation, ETC enzyme activities appear partially refractory to treatment. Accordingly, treatment with >10 μM CoQ10 may be required to restore ETC enzyme activities to control level. Accordingly, these results have important implication for the treatment of the neurological presentations of CoQ10 deficiency and indicate that high doses of CoQ10 may be required to elicit therapeutic efficacy.
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Affiliation(s)
- K E Duberley
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - S J R Heales
- Neurometabolic Unit, National Hospital, London, UK; Department of Clinical Pathology and Metabolic Unit, Great Ormond Street Hospital for Children, London, UK
| | - A Y Abramov
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - A Chalasani
- Neurometabolic Unit, National Hospital, London, UK
| | - J M Land
- Neurometabolic Unit, National Hospital, London, UK
| | - S Rahman
- Metabolic Unit, Great Ormond Street Hospital for Children, London, UK
| | - I P Hargreaves
- Neurometabolic Unit, National Hospital, London, UK; Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK.
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22
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Hughes SD, Kanabus M, Anderson G, Hargreaves IP, Rutherford T, O'Donnell M, Cross JH, Rahman S, Eaton S, Heales SJR. The ketogenic diet component decanoic acid increases mitochondrial citrate synthase and complex I activity in neuronal cells. J Neurochem 2014; 129:426-33. [PMID: 24383952 DOI: 10.1111/jnc.12646] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 12/10/2013] [Accepted: 12/30/2013] [Indexed: 11/28/2022]
Abstract
The Ketogenic diet (KD) is an effective treatment with regards to treating pharmaco-resistant epilepsy. However, there are difficulties around compliance and tolerability. Consequently, there is a need for refined/simpler formulations that could replicate the efficacy of the KD. One of the proposed hypotheses is that the KD increases cellular mitochondrial content which results in elevation of the seizure threshold. Here, we have focussed on the medium-chain triglyceride form of the diet and the observation that plasma octanoic acid (C8) and decanoic acid (C10) levels are elevated in patients on the medium-chain triglyceride KD. Using a neuronal cell line (SH-SY5Y), we demonstrated that 250-μM C10, but not C8, caused, over a 6-day period, a marked increase in the mitochondrial enzyme, citrate synthase along with complex I activity and catalase activity. Increased mitochondrial number was also indicated by electron microscopy. C10 is a reported peroxisome proliferator activator receptor γ agonist, and the use of a peroxisome proliferator activator receptor γ antagonist was shown to prevent the C10-mediated increase in mitochondrial content and catalase. C10 may mimic the mitochondrial proliferation associated with the KD and raises the possibility that formulations based on this fatty acid could replace a more complex diet. We propose that decanoic acid (C10) results in increased mitochondrial number. Our data suggest that this may occur via the activation of the PPARγ receptor and its target genes involved in mitochondrial biogenesis. This finding could be of significant benefit to epilepsy patients who are currently on a strict ketogenic diet. Evidence that C10 on its own can modulate mitochondrial number raises the possibility that a simplified and less stringent C10-based diet could be developed.
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Affiliation(s)
- Sean David Hughes
- Clinical and Molecular Genetics Unit, UCL Institute of Child Health, London, UK; Chemical Pathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
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23
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Bowron A, Frost R, Powers VEC, Thomas PH, Heales SJR, Steward CG. Diagnosis of Barth syndrome using a novel LC-MS/MS method for leukocyte cardiolipin analysis. J Inherit Metab Dis 2013; 36:741-6. [PMID: 23109063 DOI: 10.1007/s10545-012-9552-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 10/08/2012] [Accepted: 10/10/2012] [Indexed: 11/28/2022]
Abstract
Barth syndrome (BTHS) is an X-linked disorder characterised by cardiomyopathy, skeletal myopathy, growth retardation, neutropenia and 3-methylglutaconic aciduria. It is caused by mutations in the TAZ gene which codes for tafazzin, a protein with acyl transferase activity involved in synthesis of cardiolipin. Monolysocardiolipin (MLCL) is an intermediate in this process. Diagnosis of BTHS is difficult, as clinical and biochemical features are variable and numerous TAZ mutations have been described. These factors, together with lack of a straightforward diagnostic test are thought to have contributed to under-diagnosis of the condition. A novel method for cardiolipin analysis by reversed-phase ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) is reported which is less complicated and faster than previously described methods and uses a readily available sample type. The equipment, reagents and expertise required are found in most clinical laboratories performing metabolic investigations. Leukocytes were prepared from whole blood, phospholipids extracted and tetralinoleyl cardiolipin (CL4) and MLCL analysed by UPLC-MS/MS. Reference values were derived from analysis of 76 control and 23 BTHS samples as follows: CL4 in controls >132 (95 % CI 100-169), BTHS <30.2 (21.3-40.4) pmol/mg protein; MLCL/CL4 ratio in controls <0.006 (0.004-0.009) and >2.52 (1.51-4.22) in BTHS patients. We describe an improved method for CL4 and MLCL/CL4 analysis which can be incorporated into the routine work of a clinical biochemistry laboratory. It shows 100 % sensitivity and specificity for BTHS, making it a suitable diagnostic test.
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Affiliation(s)
- Ann Bowron
- Department of Clinical Biochemistry, Bristol Royal Infirmary, University Hospitals Bristol NHS Foundation Trust, Bristol BS2 8HW, UK.
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24
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Duberley KEC, Hargreaves IP, Chaiwatanasirikul KA, Heales SJR, Land JM, Rahman S, Mills K, Eaton S. Coenzyme Q10 quantification in muscle, fibroblasts and cerebrospinal fluid by liquid chromatography/tandem mass spectrometry using a novel deuterated internal standard. Rapid Commun Mass Spectrom 2013; 27:924-930. [PMID: 23592193 DOI: 10.1002/rcm.6529] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 01/29/2013] [Accepted: 01/31/2013] [Indexed: 06/02/2023]
Abstract
RATIONALE Neurological dysfunction is common in primary coenzyme Q10 (2,3-dimethoxy, 5-methyl, 6-polyisoprene parabenzoquinone; CoQ10 ; ubiquinone) deficiencies, the most readily treatable subgroup of mitochondrial disorders. Therapeutic benefit from CoQ10 supplementation has also been noted in other neurodegenerative diseases. CoQ10 can be measured by high-performance liquid chromatography (HPLC) in plasma, muscle or leucocytes; however, there is no reliable method to quantify CoQ10 in cerebrospinal fluid (CSF). Additionally, many methods use CoQ9 , an endogenous ubiquinone in humans, as an internal standard. METHODS Deuterated CoQ10 (d6 -CoQ10 ) was synthesised by a novel, simple, method. Total CoQ10 was measured by liquid chromatography/tandem mass spectrometry (LC/MS/MS) using d6 -CoQ10 as internal standard and 5 mM methylamine as an ion-pairing reagent. Chromatography was performed using a Hypsersil GOLD C4 column (150 × 3 mm, 3 µm). RESULTS CoQ10 levels were linear over a concentration range of 0-200 nM (R(2) = 0.9995). The lower limit of detection was 2 nM. The inter-assay coefficient of variation (CV) was 3.6% (10 nM) and 4.3% (20 nM), and intra-assay CV 3.4% (10 nM) and 3.6% (20 nM). Reference ranges were established for CoQ10 in CSF (5.7-8.7 nM; n = 17), fibroblasts (57.0-121.6 pmol/mg; n = 50) and muscle (187.3-430.1 pmol/mg; n = 15). CONCLUSIONS Use of d6 -CoQ10 internal standard has enabled the development of a sensitive LC/MS/MS method to accurately determine total CoQ10 levels. Clinical applications of CSF CoQ10 determination include identification of patients with cerebral CoQ10 deficiency, and monitoring CSF CoQ10 levels following supplementation.
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Affiliation(s)
- Kate E C Duberley
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
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25
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Heales SJR, Bolaños JP. Professor John B. Clark, Bsc PhD DSc: a neurochemistry pioneer and true gentleman. J Neurochem 2013. [DOI: 10.1111/jnc.12238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Simon J. R. Heales
- UCL; Institute of Child Health and Great Ormond Street Hospital for Children; London UK
| | - Juan P. Bolaños
- Institute of Functional Biology and Genomics; University of Salamanca-CSIC; Salamanca Spain
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26
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Gegg ME, Burke D, Heales SJR, Cooper JM, Hardy J, Wood NW, Schapira AHV. Glucocerebrosidase deficiency in substantia nigra of parkinson disease brains. Ann Neurol 2012; 72:455-63. [PMID: 23034917 PMCID: PMC3638323 DOI: 10.1002/ana.23614] [Citation(s) in RCA: 422] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Objective Mutations in the glucocerebrosidase gene (GBA) represent a significant risk factor for developing Parkinson disease (PD). We investigated the enzymatic activity of glucocerebrosidase (GCase) in PD brains carrying heterozygote GBA mutations (PD+GBA) and sporadic PD brains. Methods GCase activity was measured using a fluorescent assay in cerebellum, frontal cortex, putamen, amygdala, and substantia nigra of PD+GBA (n = 9–14) and sporadic PD brains (n = 12–14). Protein expression of GCase and other lysosomal proteins was determined by western blotting. The relation between GCase, α-synuclein, and mitochondria function was also investigated in vitro. Results A significant decrease in GCase activity was observed in all PD+GBA brain areas except the frontal cortex. The greatest deficiency was in the substantia nigra (58% decrease; p < 0.01). GCase activity was also significantly decreased in the substantia nigra (33% decrease; p < 0.05) and cerebellum (24% decrease; p < 0.05) of sporadic PD brains. GCase protein expression was lower in PD+GBA and PD brains, whereas increased C/EBP homologous protein and binding immunoglobulin protein levels indicated that the unfolded protein response was activated. Elevated α-synuclein levels or PTEN-induced putative kinase 1 deficiency in cultured cells had a significant effect on GCase protein levels. Interpretation GCase deficiency in PD brains with GBA mutations is a combination of decreased catalytic activity and reduced protein levels. This is most pronounced in the substantia nigra. Biochemical changes involved in PD pathogenesis affect wild-type GCase protein expression in vitro, and these could be contributing factors to the GCase deficiency observed in sporadic PD brains. ANN NEUROL 2012;72:455–463.
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Affiliation(s)
- Matthew E Gegg
- Department of Clinical Neurosciences, University College London Institute of Neurology
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27
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Heales SJR, Menzes A, Davey GP. Depletion of glutathione does not affect electron transport chain complex activity in brain mitochondria: Implications for Parkinson disease and postmortem studies. Free Radic Biol Med 2011; 50:899-902. [PMID: 21145387 DOI: 10.1016/j.freeradbiomed.2010.11.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 11/05/2010] [Accepted: 11/30/2010] [Indexed: 01/07/2023]
Abstract
Glutathione is an important antioxidant in the brain that appears to be decreased, in conjunction with mitochondrial complex I activity, in Parkinson disease patients. In postmortem analysis, measurement of glutathione levels and complex I activity can be delayed up to 20h. We investigated whether depletion of glutathione in the preweanling rat induces a reduction in complex I activity in brain mitochondria and the effects that postmortem delay has on glutathione levels and electron transport chain activity. After injection with the glutamate-cysteine ligase inhibitor, buthionine sulfoximine (L-BSO), glutathione levels were decreased by 53% compared to the control values in whole-brain homogenates. During postmortem delay of 24h, in which animals were kept at 4°C, the levels of glutathione decreased in the control group by 58% and in the L-BSO-treated group by 79%. However, during this period, there were no changes in mitochondrial electron transport chain complex I, II-III, or IV activity in either group. These results suggest that a preexisting deficiency of glutathione or a loss of glutathione during postmortem delay does not influence mitochondrial respiratory chain activity in the brain.
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Affiliation(s)
- Simon J R Heales
- Clinical and Molecular Genetics Unit, University College London Institute of Child Health, London WC1N 1EH, UK
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28
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Ling H, Polke JM, Sweeney MG, Haworth A, Sandford CA, Heales SJR, Wood NW, Davis MB, Lees AJ. An intragenic duplication in guanosine triphosphate cyclohydrolase-1 gene in a dopa-responsive dystonia family. Mov Disord 2011; 26:905-9. [PMID: 21287604 DOI: 10.1002/mds.23593] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 11/16/2010] [Accepted: 11/22/2010] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Autosomal dominant dopa-responsive dystonia is commonly caused by mutations in the guanosine triphosphate cyclohydrolase-1 gene. METHODS We report a British family that has been followed for more than 20 years in which no mutations were previously identified. RESULTS Reanalysis of this pedigree detected a duplication of guanosine triphosphate cyclohydrolase-1 exon 2 in affected family members. mRNA analysis showed a mutant transcript with a tandem exon 2 duplication. Four family members developed dopa-responsive dystonia, with onset in their late teens, and subsequently developed restless leg syndrome and migraine. CONCLUSIONS This is the first report of an intragenic guanosine triphosphate cyclohydrolase-1 duplication in a dopa-responsive dystonia family.
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Affiliation(s)
- Helen Ling
- Reta Lila Weston Institute of Neurological Studies, Institute of Neurology, University College London, London, United Kingdom
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29
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Ioannou N, Hargreaves IP, Allen G, Duberley K, Land JM, Heales SJR. Bezafibrate induced increase in mitochondrial electron transport chain complex IV activity in human astrocytoma cells: Implications for mitochondrial cytopathies and neurodegenerative diseases. Biofactors 2010; 36:468-73. [PMID: 20872762 DOI: 10.1002/biof.120] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Accepted: 07/10/2010] [Indexed: 01/08/2023]
Abstract
Mitochondrial encephalomyopathies resulting from electron transport chain (ETC) dysfunction can present with a wide spectrum of clinical manifestations having significant neuropathology and a progressive nature. Despite advances in diagnosis of ETC disorders, treatment still remains inadequate. A recent study in fibroblasts and myoblasts revealed the ability of fibrate treatment to correct ETC enzyme deficiencies. Therefore, fibrates may represent potential therapeutic agents to correct the neurological ETC impairment responsible for the encephalopathic presentation of these disorders. Consequently, this study assessed the effect of bezafibrate on human astrocytoma (HA) 1321N cell ETC activity and coenzyme Q(10) (CoQ(10) ) status. HA cells were incubated for 72 H with 300 μM or 500 μM bezafibrate and for 7 days with only 500 μM bezafibrate. A significant effect on ETC activity was observed after 7 days incubation with 500 μM bezafibrate yielding a 130% (P < 0.05) increase in complex IV activity, accompanied by a 33% (P < 0.05) increase in cellular ATP level and a 25% (P < 0.001) decrease in extracellular lactate/pyruvate ratio compared to control levels. Following 7 days culture with bezafibrate, the CoQ(10) status of the HA cells appeared to increase although this was not found to be significant. The results of this study have indicated evidence of a bezafibrate induced increase in ETC complex IV activity. Further studies are required to assess the ability of bezafibrate treatment to correct neurological ETC impairment in available animal models of ETC dysfunction before the therapeutic efficacy of this pharmacological agent can be further considered in the treatment of the encephalopathic presentation of ETC disorders.
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Affiliation(s)
- Nicola Ioannou
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
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30
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Duncan AJ, Hargreaves IP, Damian MS, Land JM, Heales SJR. Decreased ubiquinone availability and impaired mitochondrial cytochrome oxidase activity associated with statin treatment. Toxicol Mech Methods 2010; 19:44-50. [PMID: 19778232 DOI: 10.1080/15376510802305047] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
In order to investigate the potential involvement of mitochondrial electron transport chain (ETC) dysfunction in myotoxicity associated with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor (statin) treatment, assessment was made of ETC activity and ubiquinone status in two patients experiencing myopathy following treatment with simvastatin (40 mg/day) and cyclosporin (patient 1) and simvastatin (40 mg/day) and itraconazole (patient 2). Analysis of skeletal muscle biopsies revealed a decreased ubiquinone status (77 and 132; reference range: 140-580 pmol/mg) and cytochrome oxidase (complex IV) activity (0.006 and 0.007 reference range: 0.014-0.034). To assess statin treatment in the absence of possible pharmacological interference from cyclosporin or itraconazole, primary astrocytes were cultured with lovastatin (100 microM). Lovastatin treatment resulted in a decrease in ubiquinone (97.9 +/- 14.9; control: 202.9 +/- 18.4 pmol/mg; p < 0.05), and complex IV activity (0.008 +/- 0.001; control: 0.011 +/- 0.001; p < 0.05) relative to control. These data, coupled with the patient findings, indicate a possible association between statin treatment, decreased ubiquinone status, and loss of complex IV activity.
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Affiliation(s)
- Andrew J Duncan
- Department of Molecular Neuroscience, UCL Institute of Neurology, London WC1N 1BG, UK
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31
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Allen GFG, Neergheen V, Oppenheim M, Fitzgerald JC, Footitt E, Hyland K, Clayton PT, Land JM, Heales SJR. Pyridoxal 5'-phosphate deficiency causes a loss of aromatic L-amino acid decarboxylase in patients and human neuroblastoma cells, implications for aromatic L-amino acid decarboxylase and vitamin B(6) deficiency states. J Neurochem 2010; 114:87-96. [PMID: 20403077 DOI: 10.1111/j.1471-4159.2010.06742.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pyridoxal 5'-phosphate, the active form of vitamin B(6), is an essential cofactor for multiple enzymes, including aromatic l-amino acid decarboxylase that catalyses the final stage in the production of the neurotransmitters dopamine and serotonin. In two patients with inherited disorders of vitamin B(6) metabolism, we observed reductions in plasma aromatic l-amino acid decarboxylase activity. In one patient, this change was related to an increase in K(m) for pyridoxal 5'-phosphate. Furthermore, pyridoxal 5'-phosphate-deficient human SH-SY5Y neuroblastoma cells were found to exhibit reduced levels of aromatic l-amino acid decarboxylase activity and protein but with no alteration in expression. Further reductions in activity and protein were observed with the addition of the vitamin B(6) antagonist 4-deoxypyridoxine, which also reduced aromatic l-amino acid decarboxylase mRNA levels. Neither pyridoxal 5'-phosphate deficiency nor the addition of 4-deoxypyridoxine affected aromatic l-amino acid decarboxylase stability over 8 h with protein synthesis inhibited. Increasing extracellular availability of pyridoxal 5'-phosphate was not found to have any significant effect on intracellular pyridoxal 5'-phosphate concentrations or on aromatic l-amino acid decarboxylase. These findings suggest that maintaining adequate pyridoxal 5'-phosphate availability may be important for optimal treatment of aromatic l-amino acid decarboxylase deficiency and l-dopa-responsive conditions.
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Affiliation(s)
- George F G Allen
- Department of Molecular Neuroscience, UCL Institute of Neurology, London WC1N 3BG, UK.
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32
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Bolaños JP, Heales SJR. Persistent mitochondrial damage by nitric oxide and its derivatives: neuropathological implications. Front Neuroenergetics 2010; 2:1. [PMID: 20162100 PMCID: PMC2822548 DOI: 10.3389/neuro.14.001.2010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Accepted: 01/18/2010] [Indexed: 12/31/2022]
Abstract
Approximately 15 years ago we reported that cytochrome c oxidase (CcO) was persistently inhibited as a consequence of endogenous induction and activation of nitric oxide (•NO) synthase-2 (NOS2) in astrocytes. Furthermore, the reactive nitrogen species implicated was peroxynitrite. In contrast to the reversible inhibition by •NO, which occurs rapidly, in competition with O2, and has signaling regulatory implications, the irreversible CcO damage by peroxynitrite is progressive in nature and follows and/or is accompanied by damage to other key mitochondrial bioenergetic targets. In purified CcO it has been reported that the irreversible inhibition occurs through a mechanism involving damage of the heme a3-CuB binuclear center leading to an increase in the Km for oxygen. Astrocyte survival, as a consequence of peroxynitrite exposure, is preserved due to their robust bioenergetic and antioxidant defense mechanisms. However, by releasing peroxynitrite to the neighboring neurons, whose antioxidant defense can, under certain conditions, be fragile, activated astrocytes trigger bioenergetic stress leading to neuronal cell death. Thus, such irreversible inhibition of CcO by peroxynitrite may be a plausible mechanism for the neuronal death associated with neurodegenerative diseases, in which the activation of astrocytes plays a crucial role.
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Affiliation(s)
- Juan P Bolaños
- Department of Biochemistry and Molecular Biology, Institute of Neurosciences of Castilla- Leon, University of Salamanca Salamanca, Spain
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Rodriguez-Cuenca S, Cochemé HM, Logan A, Abakumova I, Prime TA, Rose C, Vidal-Puig A, Smith AC, Rubinsztein DC, Fearnley IM, Jones BA, Pope S, Heales SJR, Lam BYH, Neogi SG, McFarlane I, James AM, Smith RAJ, Murphy MP. Consequences of long-term oral administration of the mitochondria-targeted antioxidant MitoQ to wild-type mice. Free Radic Biol Med 2010; 48:161-72. [PMID: 19854266 DOI: 10.1016/j.freeradbiomed.2009.10.039] [Citation(s) in RCA: 164] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 09/02/2009] [Accepted: 10/17/2009] [Indexed: 12/01/2022]
Abstract
The mitochondria-targeted quinone MitoQ protects mitochondria in animal studies of pathologies in vivo and is being developed as a therapy for humans. However, it is unclear whether the protective action of MitoQ is entirely due to its antioxidant properties, because long-term MitoQ administration may alter whole-body metabolism and gene expression. To address this point, we administered high levels of MitoQ orally to wild-type C57BL/6 mice for up to 28 weeks and investigated the effects on whole-body physiology, metabolism, and gene expression, finding no measurable deleterious effects. In addition, because antioxidants can act as pro-oxidants under certain conditions in vitro, we examined the effects of MitoQ administration on markers of oxidative damage. There were no changes in the expression of mitochondrial or antioxidant genes as assessed by DNA microarray analysis. There were also no increases in oxidative damage to mitochondrial protein, DNA, or cardiolipin, and the activities of mitochondrial enzymes were unchanged. Therefore, MitoQ does not act as a pro-oxidant in vivo. These findings indicate that mitochondria-targeted antioxidants can be safely administered long-term to wild-type mice.
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Affiliation(s)
- Sergio Rodriguez-Cuenca
- Department of Clinical Biochemistry, University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Cambridge CB2 0QQ, UK
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Shelley P, Martin-Gronert MS, Rowlerson A, Poston L, Heales SJR, Hargreaves IP, McConnell JM, Ozanne SE, Fernandez-Twinn DS. Altered skeletal muscle insulin signaling and mitochondrial complex II-III linked activity in adult offspring of obese mice. Am J Physiol Regul Integr Comp Physiol 2009; 297:R675-81. [PMID: 19535678 DOI: 10.1152/ajpregu.00146.2009] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We recently reported insulin resistance in adult offspring of obese C57BL/6J mice. We have now evaluated whether parameters of skeletal muscle structure and function may play a role in insulin resistance in this model of developmental programming. Obesity was induced in female mice by feeding a highly palatable sugar and fat-rich diet for 6 wk prior to pregnancy, and during pregnancy and lactation. Offspring of obese dams were weaned onto standard laboratory chow. At 3 mo of age, skeletal muscle insulin signaling protein expression, mitochondrial electron transport chain activity (ETC), muscle fiber type, fiber density, and fiber cross-sectional area were compared with that of offspring of control dams weaned onto the chow diet. Female offspring of obese dams demonstrated decreased skeletal muscle expression of p110beta, the catalytic subunit of PI3K (P < 0.01), as well as reduced Akt phosphorylation at Serine residue 473 compared with control offspring. Male offspring of obese dams demonstrated increased skeletal muscle Akt2 and PKCzeta expression (P < 0.01; P < 0.001, respectively). A decrease in mitochondrial-linked complex II-III was observed in male offspring of obese dams (P < 0.01), which was unrelated to CoQ deficiency. This was not observed in females. There were no differences in muscle fiber density between offspring of obese dams and control offspring in either sex. Sex-related alterations in key insulin-signaling proteins and in mitochondrial ETC may contribute to a state of insulin resistance in offspring of obese mice.
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Affiliation(s)
- Piran Shelley
- Division of Reproduction and Endocrinology, King's College London, St. Thomas's Hospital, London, UK
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35
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Kurian MA, Zhen J, Cheng SY, Li Y, Mordekar SR, Jardine P, Morgan NV, Meyer E, Tee L, Pasha S, Wassmer E, Heales SJR, Gissen P, Reith MEA, Maher ER. Homozygous loss-of-function mutations in the gene encoding the dopamine transporter are associated with infantile parkinsonism-dystonia. J Clin Invest 2009; 119:1595-603. [PMID: 19478460 DOI: 10.1172/jci39060] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Accepted: 04/08/2009] [Indexed: 11/17/2022] Open
Abstract
Genetic variants of the SLC6A3 gene that encodes the human dopamine transporter (DAT) have been linked to a variety of neuropsychiatric disorders, particularly attention deficit hyperactivity disorder. In addition, the homozygous Slc6a3 knockout mouse displays a hyperactivity phenotype. Here, we analyzed 2 unrelated consanguineous families with infantile parkinsonism-dystonia (IPD) syndrome and identified homozygous missense SLC6A3 mutations (p.L368Q and p.P395L) in both families. Functional studies demonstrated that both mutations were loss-of-function mutations that severely reduced levels of mature (85-kDa) DAT while having a differential effect on the apparent binding affinity of dopamine. Thus, in humans, loss-of-function SLC6A3 mutations that impair DAT-mediated dopamine transport activity are associated with an early-onset complex movement disorder. Identification of the molecular basis of IPD suggests SLC6A3 as a candidate susceptibility gene for other movement disorders associated with parkinsonism and/or dystonic features.
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Affiliation(s)
- Manju A Kurian
- Department of Medical and Molecular Genetics, University of Birmingham School of Medicine, Institute of Biomedical Research, Birmingham, United Kingdom
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Allen GFG, Land JM, Heales SJR. A new perspective on the treatment of aromatic L-amino acid decarboxylase deficiency. Mol Genet Metab 2009; 97:6-14. [PMID: 19231266 DOI: 10.1016/j.ymgme.2009.01.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 01/16/2009] [Accepted: 01/16/2009] [Indexed: 11/26/2022]
Abstract
The final step in production of the neurotransmitters dopamine and serotonin is catalyzed by aromatic l-amino acid decarboxylase (AADC). AADC deficiency is a debilitating genetic condition that results in a deficit in these neurotransmitters, and manifests in infancy as a severe movement disorder with developmental delay. Response to current treatments is often disappointing. We have reviewed the literature to look for improvements to the current treatment strategy and also for new directions for AADC deficiency treatment. There may be differences in the mode of action, side-effect risk and effectiveness between different dopamine agonists and monoamine oxidase inhibitors currently used for AADC deficiency treatment. The range of these drugs used requires re-evaluation as some may have greater efficacy than others. Pyridoxal 5'-phosphate, the AADC cofactor may stabilize AADC and could increase AADC activity. Pyridoxal 5'-phosphate could have advantages as a treatment instead of pyridoxine. Atypical neuroleptics and peripheral AADC inhibitors both increase AADC activity in vivo and could be a future direction for AADC deficiency treatment and related conditions. Parkinson's disease gene therapy to deliver and express the human AADC gene in striatum is being tested in humans. Consequently gene therapy for AADC deficiency could be a realistic aim however an animal model of AADC deficiency is important for further progression.
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Affiliation(s)
- George F G Allen
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square House, Queen Square, London WC1N 3BG, UK.
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Oppenheim MLS, Hargreaves IP, Pope S, Land JM, Heales SJR. Mitochondrial cytochrome c release: a factor to consider in mitochondrial disease? J Inherit Metab Dis 2009; 32:269-73. [PMID: 19169843 DOI: 10.1007/s10545-009-1061-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Revised: 12/19/2008] [Accepted: 12/22/2008] [Indexed: 10/21/2022]
Abstract
The pathogenesis of mitochondrial disorders has largely focused on the impairment of cellular energy metabolism. However, mitochondrial dysfunction has also been implicated as a factor in the initiation of apoptosis due to the translocation of cytochrome c, from mitochondria to the cytosol, and the subsequent cleavage of pro-caspase 3. In this study, we determined the cytochrome c content of cytosols (skeletal muscle) prepared from 22 patients with evidence of compromised mitochondrial electron transport chain enzyme activity and 26 disease controls. The cytochrome c content of the mitochondrial electron transport chain-deficient group was found to be significantly (p < 0.02) elevated when compared with the control group (63.7 +/- 15.5 versus 27.7 +/- 2.5 ng/mg protein). Furthermore, a relationship between the cytosolic cytochrome c content of skeletal muscle and complex I and complex IV activities was demonstrated. Such data raise the possibility that mitochondrial cytochrome c release may be a feature of mitochondrial disorders, particularly for those patients with marked deficiencies of respiratory chain enzymes. Whether initiation of apoptosis occurs as a direct consequence of this cytochrome c release has not been fully evaluated here. However, for one patient with the greatest documented cytosolic cytochrome c content, caspase 3 could be demonstrated in the cytosolic preparation. Further work is required in order to establish whether a relationship also exists between caspase 3 formation and the magnitude of respiratory chain deficiency.
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Affiliation(s)
- M L S Oppenheim
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
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38
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Stanyer L, Jorgensen W, Hori O, Clark JB, Heales SJR. Inactivation of brain mitochondrial Lon protease by peroxynitrite precedes electron transport chain dysfunction. Neurochem Int 2008; 53:95-101. [PMID: 18598728 DOI: 10.1016/j.neuint.2008.06.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Revised: 05/30/2008] [Accepted: 06/02/2008] [Indexed: 12/01/2022]
Abstract
The accumulation of oxidatively modified proteins has been shown to be a characteristic feature of many neurodegenerative disorders and its regulation requires efficient proteolytic processing. One component of the mitochondrial proteolytic system is Lon, an ATP-dependent protease that has been shown to degrade oxidatively modified aconitase in vitro and may thus play a role in defending against the accumulation of oxidized matrix proteins in mitochondria. Using an assay system that allowed us to distinguish between basal and ATP-stimulated Lon protease activity, we have shown in isolated non-synaptic rat brain mitochondria that Lon protease is highly susceptible to oxidative inactivation by peroxynitrite (ONOO(-)). This susceptibility was more pronounced with regard to ATP-stimulated activity, which was inhibited by 75% in the presence of a bolus addition of 1mM ONOO(-), whereas basal unstimulated activity was inhibited by 45%. Treatment of mitochondria with a range of peroxynitrite concentrations (10-1000 microM) revealed that a decline in Lon protease activity preceded electron transport chain (ETC) dysfunction (complex I, II-III and IV) and that ATP-stimulated activity was approximately fivefold more sensitive than basal Lon protease activity. Furthermore, supplementation of mitochondrial matrix extracts with reduced glutathione, following ONOO(-) exposure, resulted in partial restoration of basal and ATP-stimulated activity, thus suggesting possible redox regulation of this enzyme complex. Taken together these findings suggest that Lon protease may be particularly vulnerable to inactivation in conditions associated with GSH depletion and elevated oxidative stress.
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Affiliation(s)
- Lee Stanyer
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London, UK.
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39
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Pope SAS, Milton R, Heales SJR. Astrocytes protect against copper-catalysed loss of extracellular glutathione. Neurochem Res 2008; 33:1410-8. [PMID: 18335314 DOI: 10.1007/s11064-008-9602-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Accepted: 01/23/2008] [Indexed: 10/22/2022]
Abstract
Glutathione (GSH) is one of the major antioxidants in the brain. GSH is secreted by astrocytes and this extracellular GSH is used by neurones to maintain and increase their intracellular GSH levels. For efficient GSH trafficking between astrocytes and neurones, GSH needs to be maintained in the reduced form. In model systems, GSH trafficking has been shown to be essential for neuroprotection against a variety of stress conditions. Previously we and others have shown that GSH and thiols are unstable in cell culture media and are easily oxidised. In the present study it is shown that nanomolar concentrations of copper (II) ions can cause decay of GSH in cell culture media. Increased free or redox active copper has been implicated in a variety of diseases and degradation of extracellular GSH is a possible mechanism by which it exerts its harmful effects. Rat astrocytes, a human astrocytoma cell line and astrocyte-conditioned media, in the absence of cells, are able to retard this copper-catalysed decay of GSH and maintain GSH in its reduced form. The protective effect of astrocytes appears to be a combination of copper removing and antioxidant mechanisms. The importance of these protective mechanisms is discussed with regards to neurodegenerative diseases.
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Affiliation(s)
- Simon A S Pope
- Division of Neurochemistry, Department of Molecular Neuroscience, Institute of Neurology, University College London, London WC1N 3BG, UK.
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40
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Lam AAJ, Heales SJR. Nitric oxide accelerates the degradation of tetrahydrobiopterin but not total neopterin in cerebrospinal fluid; potential implications for the assessment of tetrahydrobiopterin metabolism. Ann Clin Biochem 2007; 44:394-6. [PMID: 17594789 DOI: 10.1258/000456307780945741] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Assessment of total neopterin and tetrahydrobioterin (BH4) concentrations in cerebrospinal fluid (CSF) can be used to identify potential disorders of BH4 biosynthesis. In this study, we demonstrate that exposure of CSF to nitric oxide leads to an accelerated degradation of BH4 but does not affect the total neopterin concentration. These data suggest that in those conditions associated with increased nitric oxide formation, perturbation of the total neopterin to BH4 ratio could occur. Under such circumstances a putative diagnosis of a defect in BH4 biosynthesis may erroneously be proposed. Assessment of central nitric oxide generation may therefore be a useful adjunct to the determination of CSF pterin status.
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Affiliation(s)
- A A J Lam
- Neurometabolic Unit, National Hospital, Queen Square & Department of Molecular Neuroscience Institute of Neurology (UCL), Queen Square, London, UK
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41
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Foxton RH, Land JM, Heales SJR. Tetrahydrobiopterin availability in Parkinson's and Alzheimer's disease; potential pathogenic mechanisms. Neurochem Res 2007; 32:751-6. [PMID: 17191137 DOI: 10.1007/s11064-006-9201-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Accepted: 10/11/2006] [Indexed: 10/23/2022]
Abstract
Within the central nervous system, tetrahydrobiopterin (BH4) is an essential cofactor for dopamine and serotonin synthesis. In addition, BH4 is now established to be an essential cofactor for all isoforms of nitric oxide synthase (NOS). Inborn errors of metabolism affecting BH4 availability are well documented and the clinical presentation can be attributed to a paucity of dopamine, serotonin, and nitric oxide (NO) generation. In this article, we have focussed upon the sensitivity of BH4 to oxidative catabolism and the observation that when BH4 is limiting some cellular sources of NOS may generate superoxide whilst other BH4 saturated NOS enzymes may be generating NO. Such a scenario could favor peroxynitrite generation. If peroxynitrite is not scavenged, e.g., by antioxidants such as reduced glutathione, irreversible damage to critical cellular enzymes could ensue. Such targets include components of the mitochondrial electron transport chain, alpha ketoglutarate dehydrogenase and possibly pyruvate dehydrogenase. Such a cascade of events is hypothesized, in this article, to occur in neurodegenerative conditions such as Parkinson's and Alzheimer's disease.
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Affiliation(s)
- Richard H Foxton
- Department of Molecular Neuroscience, Institute of Neurology, Queen Square, London, WC1N 3BG, UK
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42
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Lam AAJ, Hyland K, Heales SJR. Tetrahydrobiopterin availability, nitric oxide metabolism and glutathione status in the hph-1 mouse; implications for the pathogenesis and treatment of tetrahydrobiopterin deficiency states. J Inherit Metab Dis 2007; 30:256-62. [PMID: 17242981 DOI: 10.1007/s10545-006-0502-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2006] [Revised: 12/13/2006] [Accepted: 12/18/2006] [Indexed: 01/23/2023]
Abstract
Tetrahydrobiopterin (BH4) is an essential cofactor for all isoforms of nitric oxide synthase. While it is well established that BH4 deficiency states are associated with impairment of dopamine, serotonin and phenylalanine metabolism, less is known with regard to the effects of deficiency of the cofactor upon nitric oxide (NO) metabolism. In this study, we have evaluated the effects of partial BH4 deficiency upon (a) tissue availability of the antioxidant glutathione, (b) basal NO production and (c) NO generation following exposure to lipopolysaccharide (LPS), which is known to increase expression of the inducible form of nitric oxide synthase. Using the hph-1 mouse, which displays a partial BH4 deficiency owing to impaired activity of GTP cyclohydrolase, we report decreased levels of glutathione in brain and kidney and evidence for decreased basal generation of nitric oxide in the periphery (as judged by the plasma nitrate plus nitrite concentration). Following LPS administration, peripheral NO generation increases. However, the concentration of plasma nitrate plus nitrite achieved was significantly decreased in the hph-1 mouse. Furthermore, LPS administration caused loss of glutathione in both wild-type and hph-1 liver and kidney. It is concluded that cofactor replacement, sufficient to fully correct a cellular BH4 deficiency, may be of benefit to patients with inborn errors of BH4 metabolism.
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Affiliation(s)
- A A J Lam
- Department of Molecular Neuroscience, Institute of Neurology, London, UK
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43
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Hargreaves IP, Duncan AJ, Wu L, Agrawal A, Land JM, Heales SJR. Inhibition of mitochondrial complex IV leads to secondary loss complex II-III activity: implications for the pathogenesis and treatment of mitochondrial encephalomyopathies. Mitochondrion 2007; 7:284-7. [PMID: 17395552 DOI: 10.1016/j.mito.2007.02.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2006] [Revised: 01/23/2007] [Accepted: 02/02/2007] [Indexed: 11/26/2022]
Abstract
Mitochondrial encephalomyopathies, arising from deficiencies of the electron transport chain (ETC) give rise to a wide clinical spectrum of presentation and are often progressive in nature. The aetiology of mitochondrial encephalomyopathies have yet to be fully elucidated, however, a successive loss of ETC function may contribute to the progressive nature of these disorders. The possibility arises that as a consequence of a primary impairment of ETC activity, secondary damage to the ETC may occur. In order to investigate this hypothesis, we established a model of cytochrome oxidase (Complex IV) deficiency in cultured human astrocytoma 1321N cells. Potassium cyanide (KCN, 1mM) resulted in a sustained 50% (p<0.01) loss of complex IV. At 24h activities of the other ETC complexes were unaffected. However, at 72h significant loss of succinate-cytochrome c reductase (complex II-III) activity expressed as a ratio to the mitochondrial marker, citrate synthase was observed. (KCN treated; 0.065+/-0.011 vs controls; 0.118+/-0.017 mean+/-SEM, n=8, p<0.05). These results provide a possible mechanism for the progressive nature of ETC defects and why in some patients multiple patterns of ETC deficiencies can be demonstrated.
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Affiliation(s)
- I P Hargreaves
- Neurometabolic Unit, National Hospital and Department of Molecular Neuroscience, Institute of Neurology, Queen Square, London WC1N 3BG, UK.
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44
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Loupatty FJ, Clayton PT, Ruiter JPN, Ofman R, Ijlst L, Brown GK, Thorburn DR, Harris RA, Duran M, Desousa C, Krywawych S, Heales SJR, Wanders RJA. Mutations in the gene encoding 3-hydroxyisobutyryl-CoA hydrolase results in progressive infantile neurodegeneration. Am J Hum Genet 2007; 80:195-9. [PMID: 17160907 PMCID: PMC1785315 DOI: 10.1086/510725] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2006] [Accepted: 10/31/2006] [Indexed: 11/03/2022] Open
Abstract
Only a single patient with 3-hydroxyisobutyryl-CoA hydrolase deficiency has been described in the literature, and the molecular basis of this inborn error of valine catabolism has remained unknown until now. Here, we present a second patient with 3-hydroxyisobutyryl-CoA hydrolase deficiency, who was identified through blood spot acylcarnitine analysis showing persistently increased levels of hydroxy-C(4)-carnitine. Both patients manifested hypotonia, poor feeding, motor delay, and subsequent neurological regression in infancy. Additional features in the newly identified patient included episodes of ketoacidosis and Leigh-like changes in the basal ganglia on a magnetic resonance imaging scan. In cultured skin fibroblasts from both patients, the 3-hydroxyisobutyryl-CoA hydrolase activity was deficient, and virtually no 3-hydroxyisobutyryl-CoA hydrolase protein could be detected by western blotting. Molecular analysis in both patients uncovered mutations in the HIBCH gene, including one missense mutation in a conserved part of the protein and two mutations affecting splicing. A carefully interpreted acylcarnitine profile will allow more patients with 3-hydroxyisobutyryl-CoA hydrolase deficiency to be diagnosed.
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Affiliation(s)
- Ference J Loupatty
- Department of Clinical Chemistry and Pediatrics, Emma Children's Hospital, Amsterdam, The Netherlands
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45
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Land JM, Heales SJR, Duncan AJ, Hargreaves IP. Some Observations upon Biochemical Causes of Ataxia and a New Disease Entity Ubiquinone, CoQ10 Deficiency. Neurochem Res 2006; 32:837-43. [PMID: 17186372 DOI: 10.1007/s11064-006-9222-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2006] [Accepted: 11/06/2006] [Indexed: 11/29/2022]
Abstract
Some hereditary ataxias are treatable and the insight required for this has come from an in depth knowledge of the phenotypes and clinical biochemistry of the conditions. This has required both fundamental and translational clinical research. Prof John Blass was fortunate to begin his career at what we can now recognise as a golden era for such studies and he worked upon two important conditions; Refsum's disease and Friedreich's ataxia. More recently the mitochondrial encephalomyopathies have been described and similar investigative work has been undertaken upon them. Ubiquinone, CoQ(10), deficiency is the most recently recognised encephalomyopathy and is itself treatable. Though rare, it is becoming increasingly recognised and patients are benefiting from the same scholarly approach to its investigation as was afforded Refsums' disease and Friedreich's ataxia.
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Affiliation(s)
- John M Land
- Neurometabolic Unit Box 105, National Hospital for Neurology & Neurosurgery, Queen Square, London, WC1N 3BG, UK.
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46
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Laube GF, Shah V, Stewart VC, Hargreaves IP, Haq MR, Heales SJR, van't Hoff WG. Glutathione depletion and increased apoptosis rate in human cystinotic proximal tubular cells. Pediatr Nephrol 2006; 21:503-9. [PMID: 16508773 DOI: 10.1007/s00467-006-0005-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2005] [Revised: 09/26/2005] [Accepted: 09/28/2005] [Indexed: 12/17/2022]
Abstract
We have determined levels of glutathione (GSH), ATP, mitochondrial complex activity and apoptosis rate in proximal tubular cells (PTCs) exfoliated from urine in cystinotic (n=9) and control (n=9) children. Intracellular GSH was significantly depleted in cystinotic PTCs compared with controls (6.8 nmol GSH/mg protein vs 11.8 nmol GSH/mg protein; P<0.001), but there were no significant differences in mitochondrial complex activities or ATP levels under basal conditions. Cystinotic PTCs showed significantly increased apoptosis rate. After PTCs had been stressed by hypoxia, there was further depletion of GSH in cystinotic and control PTCs (2.4 nmol GSH/mg protein vs 7.2 nmol GSH/mg protein; P<0.001). Hypoxic stress led to increased complex I and complex IV activities in control but not in cystinotic PTCs. ATP levels were significantly reduced in cystinotic PTCs after hypoxic stress (12.2 nmol/mg protein vs 26.9 nmol/mg protein; P<0.001). GSH depletion occurs in this in vitro model of cystinotic PTCs, is exaggerated by hypoxic stress and may contribute to reduced ATP and failure to increase complex I/IV activities. Apoptotic rate is also increased, and these mechanisms may contribute to cellular dysfunction in cultured, human cystinotic PTCs.
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Affiliation(s)
- Guido F Laube
- Nephro-urology Unit, Institute of Child Health, University College London Medical School, London, UK.
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47
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Duncan AJ, Heales SJR, Mills K, Eaton S, Land JM, Hargreaves IP. Determination of Coenzyme Q10 Status in Blood Mononuclear Cells, Skeletal Muscle, and Plasma by HPLC with Di-Propoxy-Coenzyme Q10 as an Internal Standard. Clin Chem 2005; 51:2380-2. [PMID: 16306103 DOI: 10.1373/clinchem.2005.054643] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Andrew J Duncan
- Division of Neurochemistry, Institute of Neurology, London, UK
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48
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Jacobson J, Duchen MR, Hothersall J, Clark JB, Heales SJR. Induction of mitochondrial oxidative stress in astrocytes by nitric oxide precedes disruption of energy metabolism. J Neurochem 2005; 95:388-95. [PMID: 16104850 DOI: 10.1111/j.1471-4159.2005.03374.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Inhibition of the mitochondrial electron transport chain (ETC) ultimately limits ATP production and depletes cellular ATP. However, the individual complexes of the ETC in brain mitochondria need to be inhibited by approximately 50% before causing significant depression of ATP synthesis. Moreover, the ETC is the key site for the production of intracellular reactive oxygen species (ROS) and inhibition of one or more of the complexes of the ETC may increase the rate of mitochondrial ROS generation. We asked whether partial inhibition of the ETC, to a degree insufficient to perturb oxidative phosphorylation, might nonetheless induce ROS production. Chronic increase in mitochondrial ROS might then cause oxidative damage to the ETC sufficient to produce prolonged changes in ETC function and so compound the defect. We show that the exposure of astrocytes in culture to low concentrations of nitric oxide (NO) induces an increased rate of O2*- generation that outlasts the presence of NO. No effect was seen on oxygen consumption, lactate or ATP content over the 4-6 h that the cells were exposed to NO. These data suggest that partial ETC inhibition by NO may initially cause oxidative stress rather than ATP depletion, and this may subsequently induce irreversible changes in ETC function providing the basis for a cycle of damage.
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Affiliation(s)
- Jake Jacobson
- Miriam Marks Division of Neurochemistry, Institute of Neurology, Department of Biology, University College London, London, UK.
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49
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Gegg ME, Clark JB, Heales SJR. Co-culture of neurones with glutathione deficient astrocytes leads to increased neuronal susceptibility to nitric oxide and increased glutamate-cysteine ligase activity. Brain Res 2005; 1036:1-6. [PMID: 15725395 DOI: 10.1016/j.brainres.2004.11.064] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2004] [Revised: 11/08/2004] [Accepted: 11/30/2004] [Indexed: 01/22/2023]
Abstract
The antioxidant glutathione (GSH) plays an important role in protecting the mitochondrial electron transport chain (ETC) from damage by oxidative stress in astrocytes and neurones. Neurones co-cultured with astrocytes have greater GSH levels, compared to neurones cultured alone, leading to the hypothesis that astrocytes play a key role in brain GSH metabolism by supplying essential GSH precursors to neurones. A previous study has postulated that damage to the ETC following exposure to reactive nitrogen species (RNS) is less in co-cultured neurones, compared to neurones cultured alone, because of the greater GSH levels in the former cells. To investigate this further, primary culture rat neurones were co-cultured with either rat astrocytes activated with IFN-gamma and LPS to produce NO, or NO-generating astrocytes that had been depleted of intracellular GSH by 87% following incubation with the GSH synthesis inhibitor L-buthionine-S,R-sulfoximine (L-BSO). Neurones incubated with NO-generating astrocytes depleted of GSH were unable to elevate GSH levels, unlike neurones co-cultured with NO-generating astrocytes. Complexes II + III and IV of the neuronal ETC were significantly inhibited following exposure to NO-generating astrocytes depleted of GSH. No ETC damage was observed in neurones co-cultured with NO-generating astrocytes. Although neurones co-cultured with GSH depleted astrocytes did not increase cellular GSH levels, the activity of glutamate cysteine ligase (GCL), the rate-limiting enzyme of GSH synthesis, was increased by 218%, compared to neurones cultured with control astrocytes. This suggests that neuronal GCL activity could be modulated when GSH metabolism is inhibited in neighboring astrocytes.
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Affiliation(s)
- M E Gegg
- Cellular Therapy, Institute of Ophthalmology, University College London, London EC1V 9EL, UK.
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50
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Mills PB, Surtees RAH, Champion MP, Beesley CE, Dalton N, Scambler PJ, Heales SJR, Briddon A, Scheimberg I, Hoffmann GF, Zschocke J, Clayton PT. Neonatal epileptic encephalopathy caused by mutations in the PNPO gene encoding pyridox(am)ine 5′-phosphate oxidase. Hum Mol Genet 2005; 14:1077-86. [PMID: 15772097 DOI: 10.1093/hmg/ddi120] [Citation(s) in RCA: 197] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In the mouse, neurotransmitter metabolism can be regulated by modulation of the synthesis of pyridoxal 5'-phosphate and failure to maintain pyridoxal phosphate (PLP) levels results in epilepsy. This study of five patients with neonatal epileptic encephalopathy suggests that the same is true in man. Cerebrospinal fluid and urine analyses indicated reduced activity of aromatic L-amino acid decarboxylase and other PLP-dependent enzymes. Seizures ceased with the administration of PLP, having been resistant to treatment with pyridoxine, suggesting a defect of pyridox(am)ine 5'-phosphate oxidase (PNPO). Sequencing of the PNPO gene identified homozygous missense, splice site and stop codon mutations. Expression studies in Chinese hamster ovary cells showed that the splice site (IVS3-1g>a) and stop codon (X262Q) mutations were null activity mutations and that the missense mutation (R229W) markedly reduced pyridox(am)ine phosphate oxidase activity. Maintenance of optimal PLP levels in the brain may be important in many neurological disorders in which neurotransmitter metabolism is disturbed (either as a primary or as a secondary phenomenon).
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Affiliation(s)
- Philippa B Mills
- Institute of Child Health, University College London with Great Ormond Street Hospital for Children, NHS Trust, London WC1N 1EH, UK
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