1
|
Toomey CE, Heywood WE, Evans JR, Lachica J, Pressey SN, Foti SC, Al Shahrani M, D’Sa K, Hargreaves IP, Heales S, Orford M, Troakes C, Attems J, Gelpi E, Palkovits M, Lashley T, Gentleman SM, Revesz T, Mills K, Gandhi S. Mitochondrial dysfunction is a key pathological driver of early stage Parkinson's. Acta Neuropathol Commun 2022; 10:134. [PMID: 36076304 PMCID: PMC9461181 DOI: 10.1186/s40478-022-01424-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 08/09/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The molecular drivers of early sporadic Parkinson's disease (PD) remain unclear, and the presence of widespread end stage pathology in late disease masks the distinction between primary or causal disease-specific events and late secondary consequences in stressed or dying cells. However, early and mid-stage Parkinson's brains (Braak stages 3 and 4) exhibit alpha-synuclein inclusions and neuronal loss along a regional gradient of severity, from unaffected-mild-moderate-severe. Here, we exploited this spatial pathological gradient to investigate the molecular drivers of sporadic PD. METHODS We combined high precision tissue sampling with unbiased large-scale profiling of protein expression across 9 brain regions in Braak stage 3 and 4 PD brains, and controls, and verified these results using targeted proteomic and functional analyses. RESULTS We demonstrate that the spatio-temporal pathology gradient in early-mid PD brains is mirrored by a biochemical gradient of a changing proteome. Importantly, we identify two key events that occur early in the disease, prior to the occurrence of alpha-synuclein inclusions and neuronal loss: (i) a metabolic switch in the utilisation of energy substrates and energy production in the brain, and (ii) perturbation of the mitochondrial redox state. These changes may contribute to the regional vulnerability of developing alpha-synuclein pathology. Later in the disease, mitochondrial function is affected more severely, whilst mitochondrial metabolism, fatty acid oxidation, and mitochondrial respiration are affected across all brain regions. CONCLUSIONS Our study provides an in-depth regional profile of the proteome at different stages of PD, and highlights that mitochondrial dysfunction is detectable prior to neuronal loss, and alpha-synuclein fibril deposition, suggesting that mitochondrial dysfunction is one of the key drivers of early disease.
Collapse
Affiliation(s)
- Christina E. Toomey
- Queen Square Brain Bank for Neurological Disorders, UCL Queen Square Institute of Neurology, London, UK
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
- The Francis Crick Institute, London, UK
| | - Wendy E. Heywood
- Translational Mass Spectrometry Research Group, Genetic & Genomic Medicine, Institute of Child Health, UCL, London, UK
| | - James R. Evans
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
- The Francis Crick Institute, London, UK
| | - Joanne Lachica
- Queen Square Brain Bank for Neurological Disorders, UCL Queen Square Institute of Neurology, London, UK
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| | - Sarah N. Pressey
- Queen Square Brain Bank for Neurological Disorders, UCL Queen Square Institute of Neurology, London, UK
| | - Sandrine C. Foti
- Queen Square Brain Bank for Neurological Disorders, UCL Queen Square Institute of Neurology, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Mesfer Al Shahrani
- National Hospital for Neurology and Neurosurgery & Neurometabolic Unit, UCL Great Ormond Street Institute of Child Health, London, UK
- College of Applied Medical Sciences, King Khalid University, Abha, Saudi Arabia
| | - Karishma D’Sa
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
- The Francis Crick Institute, London, UK
| | - Iain P. Hargreaves
- National Hospital for Neurology and Neurosurgery & Neurometabolic Unit, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Simon Heales
- National Hospital for Neurology and Neurosurgery & Neurometabolic Unit, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Michael Orford
- National Hospital for Neurology and Neurosurgery & Neurometabolic Unit, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Claire Troakes
- London Neurodegenerative Diseases Brain Bank, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Johannes Attems
- Newcastle Brain Tissue Resource, Institute of Neuroscience and Newcastle University Institute for Ageing, Newcastle upon Tyne, UK
| | - Ellen Gelpi
- Neurological Tissue Bank, University of Barcelona, Barcelona, Spain
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Miklos Palkovits
- Human Brain Tissue Bank, Budapest, Semmelweis University, Budapest, Hungary
| | - Tammaryn Lashley
- Queen Square Brain Bank for Neurological Disorders, UCL Queen Square Institute of Neurology, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | | | - Tamas Revesz
- Queen Square Brain Bank for Neurological Disorders, UCL Queen Square Institute of Neurology, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Kevin Mills
- Translational Mass Spectrometry Research Group, Genetic & Genomic Medicine, Institute of Child Health, UCL, London, UK
| | - Sonia Gandhi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
- The Francis Crick Institute, London, UK
| |
Collapse
|
2
|
Dobrowolski SF, Phua YL, Vockley J, Goetzman E, Blair HC. Phenylketonuria oxidative stress and energy dysregulation: Emerging pathophysiological elements provide interventional opportunity. Mol Genet Metab 2022; 136:111-117. [PMID: 35379539 PMCID: PMC9832337 DOI: 10.1016/j.ymgme.2022.03.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 03/24/2022] [Accepted: 03/25/2022] [Indexed: 01/13/2023]
Abstract
Phenylalanine hydroxylase (PAH) deficient phenylketonuria (PKU) is rightfully considered the paradigm treatable metabolic disease. Dietary substrate restriction (i.e. phenylalanine (Phe) restriction) was applied >60 years ago and remains the primary PKU management means. The traditional model of PKU neuropathophysiology dictates blood Phe over-representation directs asymmetric blood:brain barrier amino acid transport through the LAT1 transporter with subsequent increased cerebral Phe concentration and low concentrations of tyrosine (Tyr), tryptophan (Trp), leucine (Leu), valine (Val), and isoleucine (Ile). Low Tyr and Trp concentrations generate secondary serotonergic and dopaminergic neurotransmitter paucities, widely attributed as drivers of PKU neurologic phenotypes. White matter disease, a central PKU characteristic, is ascribed to Phe-mediated tissue toxicity. Impaired cerebral protein synthesis, by reduced concentrations of non-Phe large neutral amino acids, is another cited pathological mechanism. The PKU amino acid transport model suggests Phe management should be more efficacious than is realized, as even early identified, continuously treated patients that retain therapy compliance into adulthood, demonstrate neurologic disease elements. Reduced cerebral metabolism was an early-recognized element of PKU pathology. Legacy data (late 1960's to mid-1970's) determined the Phe catabolite phenylpyruvate inhibits mitochondrial pyruvate transport. Respirometry of Pahenu2 cerebral mitochondria have attenuated respiratory chain complex 1 induction in response to pyruvate substrate, indicating reduced energy metabolism. Oxidative stress is intrinsic to PKU and Pahenu2 brain tissue presents increased reactive oxygen species. Phenylpyruvate inhibits glucose-6-phosphate dehydrogenase that generates reduced niacinamide adenine dinucleotide phosphate the obligatory cofactor of glutathione reductase. Pahenu2 brain tissue metabolomics identified increased oxidized glutathione and glutathione disulfide. Over-represented glutathione disulfide argues for reduced glutathione reductase activity secondary to reduced NADPH. Herein, we review evidence of energy and oxidative stress involvement in PKU pathology. Data suggests energy deficit and oxidative stress are features of PKU pathophysiology, providing intervention-amenable therapeutic targets to ameliorate disease elements refractory to standard of care.
Collapse
Affiliation(s)
- Steven F Dobrowolski
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America.
| | - Yu Leng Phua
- Division of Medical Genetics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Jerry Vockley
- Division of Medical Genetics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Eric Goetzman
- Division of Medical Genetics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Harry C Blair
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America; Veteran's Affairs Medical Center, Pittsburgh, PA, United States of America
| |
Collapse
|
3
|
Bortoluzzi VT, Dutra Filho CS, Wannmacher CMD. Oxidative stress in phenylketonuria-evidence from human studies and animal models, and possible implications for redox signaling. Metab Brain Dis 2021; 36:523-543. [PMID: 33580861 DOI: 10.1007/s11011-021-00676-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 01/24/2021] [Indexed: 01/11/2023]
Abstract
Phenylketonuria (PKU) is one of the commonest inborn error of amino acid metabolism. Before mass neonatal screening was possible, and the success of introducing diet therapy right after birth, the typical clinical finds in patients ranged from intellectual disability, epilepsy, motor deficits to behavioral disturbances and other neurological and psychiatric symptoms. Since early diagnosis and treatment became widespread, usually only those patients who do not strictly follow the diet present psychiatric, less severe symptoms such as anxiety, depression, sleep pattern disturbance, and concentration and memory problems. Despite the success of low protein intake in preventing otherwise severe outcomes, PKU's underlying neuropathophysiology remains to be better elucidated. Oxidative stress has gained acceptance as a disturbance implicated in the pathogenesis of PKU. The conception of oxidative stress has evolved to comprehend how it could interfere and ultimately modulate metabolic pathways regulating cell function. We summarize the evidence of oxidative damage, as well as compromised antioxidant defenses, from patients, animal models of PKU, and in vitro experiments, discussing the possible clinical significance of these findings. There are many studies on oxidative stress and PKU, but only a few went further than showing macromolecular damage and disturbance of antioxidant defenses. In this review, we argue that these few studies may point that oxidative stress may also disturb redox signaling in PKU, an aspect few authors have explored so far. The reported effect of phenylalanine on the expression or activity of enzymes participating in metabolic pathways known to be responsive to redox signaling might be mediated through oxidative stress.
Collapse
Affiliation(s)
- Vanessa Trindade Bortoluzzi
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600-Anexo, Porto Alegre, RS, CEP 90.035-003, Brazil.
| | - Carlos Severo Dutra Filho
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600-Anexo, Porto Alegre, RS, CEP 90.035-003, Brazil
| | - Clovis Milton Duval Wannmacher
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600-Anexo, Porto Alegre, RS, CEP 90.035-003, Brazil
| |
Collapse
|
4
|
Turton N, Rutherford T, Thijssen D, Hargreaves IP. Putative adjunct therapies to target mitochondrial dysfunction and oxidative stress in phenylketonuria, lysosomal storage disorders and peroxisomal disorders. Expert Opin Orphan Drugs 2020. [DOI: 10.1080/21678707.2020.1850254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Affiliation(s)
- Nadia Turton
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| | - Tricia Rutherford
- Department of research and development, Vitaflo International Ltd, Liverpool, UK
| | - Dick Thijssen
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| | - Iain P Hargreaves
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| |
Collapse
|
5
|
Said RS, Mohamed HA, Kamal MM. Coenzyme Q10 mitigates ionizing radiation-induced testicular damage in rats through inhibition of oxidative stress and mitochondria-mediated apoptotic cell death. Toxicol Appl Pharmacol 2019; 383:114780. [PMID: 31618661 DOI: 10.1016/j.taap.2019.114780] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 10/05/2019] [Accepted: 10/10/2019] [Indexed: 12/24/2022]
Abstract
Radiotherapy is a common treatment modality for cancer patients; however, its use is limited by decreasing the probability of fertility in male cancer survivors. Therefore, this study aimed to define the capability of coenzyme Q10 (CoQ10), a potent stimulator of mitochondrial function, in attenuating ionizing radiation (IR)-induced spermatogenesis impairments. Male Sprague Dawley rats were exposed to a single dose of ϒ-rays (10 Gy) and/or treated with CoQ10 (10 mg/kg, orally, for 2 consecutive weeks). IR mediated irregular seminiferous tubules, which were emerged with typical morphological characteristics of apoptosis, and nuclear condensation, while CoQ10 significantly preserved the testicular structure and maintained spermatogenesis, which was displayed by higher levels of serum estradiol and testosterone. CoQ10 remarkably augmented sperm count, motility, and viability while diminished the rate of sperm-defects relatively to their counterparts after IR exposure. CoQ10 modulations in reproductive parameters were underpinned by attenuating IR-induced oxidative stress as evidenced by decreasing lipid peroxidation and increasing the antioxidant enzymes glutathione peroxidase and glutathione-s-transferase activities, and glutathione level. Supporting the involvement of CoQ10 in the anti-apoptotic response, the reduced mRNA expression levels of p53, Puma, and Bax accompanied by the increased Bcl-2 mRNA expression were observed. Subsequently, CoQ10 ameliorated the mitochondria dependent apoptotic pathway through diminishing Bax/Bcl-2 ratio, caspase-3 protein expression, and DNA fragmentation in testes of irradiated rats. Taken together, our findings showed that CoQ10 conserved against IR-induced steroidogenesis disruption through subsiding mitochondria-mediated oxidative stress injury in germinal cells.
Collapse
Affiliation(s)
- Riham S Said
- Drug Radiation Research Department, National Center for Radiation Research & Technology, Atomic Energy Authority, Cairo, Egypt.
| | - Heba A Mohamed
- Drug Radiation Research Department, National Center for Radiation Research & Technology, Atomic Energy Authority, Cairo, Egypt
| | - Mohamed M Kamal
- Pharmacology and Biochemistry Department, Faculty of Pharmacy, The British University in Egypt (BUE), Cairo, Egypt; Biochemistry Department, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| |
Collapse
|
6
|
Stepien KM, Heaton R, Rankin S, Murphy A, Bentley J, Sexton D, Hargreaves IP. Evidence of Oxidative Stress and Secondary Mitochondrial Dysfunction in Metabolic and Non-Metabolic Disorders. J Clin Med 2017; 6:E71. [PMID: 28753922 PMCID: PMC5532579 DOI: 10.3390/jcm6070071] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/07/2017] [Accepted: 07/14/2017] [Indexed: 01/07/2023] Open
Abstract
Mitochondrial dysfunction and oxidative stress have been implicated in the pathogenesis of a number of diseases and conditions. Oxidative stress occurs once the antioxidant defenses of the body become overwhelmed and are no longer able to detoxify reactive oxygen species (ROS). The ROS can then go unchallenged and are able to cause oxidative damage to cellular lipids, DNA and proteins, which will eventually result in cellular and organ dysfunction. Although not always the primary cause of disease, mitochondrial dysfunction as a secondary consequence disease of pathophysiology can result in increased ROS generation together with an impairment in cellular energy status. Mitochondrial dysfunction may result from either free radical-induced oxidative damage or direct impairment by the toxic metabolites which accumulate in certain metabolic diseases. In view of the importance of cellular antioxidant status, a number of therapeutic strategies have been employed in disorders associated with oxidative stress with a view to neutralising the ROS and reactive nitrogen species implicated in disease pathophysiology. Although successful in some cases, these adjunct therapies have yet to be incorporated into the clinical management of patients. The purpose of this review is to highlight the emerging evidence of oxidative stress, secondary mitochondrial dysfunction and antioxidant treatment efficacy in metabolic and non-metabolic diseases in which there is a current interest in these parameters.
Collapse
Affiliation(s)
- Karolina M Stepien
- The Mark Holland Metabolic Unit Salford Royal NHS Foundation Trust Stott Lane, Salford M6 8HD, UK.
| | - Robert Heaton
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK.
| | - Scott Rankin
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK.
| | - Alex Murphy
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK.
| | - James Bentley
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK.
| | - Darren Sexton
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK.
| | - Iain P Hargreaves
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK.
| |
Collapse
|
7
|
A Multiplatform Metabolomics Approach to Characterize Plasma Levels of Phenylalanine and Tyrosine in Phenylketonuria. JIMD Rep 2016; 32:69-79. [PMID: 27300702 PMCID: PMC5362559 DOI: 10.1007/8904_2016_568] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 04/15/2016] [Accepted: 04/18/2016] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Different pathophysiological mechanisms have been described in phenylketonuria (PKU) but the indirect metabolic consequences of metabolic disorders caused by elevated Phe or low Tyr concentrations remain partially unknown. We used a multiplatform metabolomics approach to evaluate the metabolic signature associated with Phe and Tyr. MATERIAL AND METHODS We prospectively included 10 PKU adult patients and matched controls. We analysed the metabolome profile using GC-MS (urine), amino-acid analyzer (urine and plasma) and nuclear magnetic resonance spectroscopy (urine). We performed a multivariate analysis from the metabolome (after exclusion of Phe, Tyr and directly derived metabolites) to explain plasma Phe and Tyr concentrations, and the clinical status. Finally, we performed a univariate analysis of the most discriminant metabolites and we identified the associated metabolic pathways. RESULTS We obtained a metabolic pattern from 118 metabolites and we built excellent multivariate models to explain Phe, Tyr concentrations and PKU diagnosis. Common metabolites of these models were identified: Gln, Arg, succinate and alpha aminobutyric acid. Univariate analysis showed an inverse correlation between Arg, alpha aminobutyric acid and Phe and a positive correlation between Arg, succinate, Gln and Tyr (p < 0.0003). Thus, we highlighted the following pathways: Arg and Pro, Ala, Asp and Glu metabolism. DISCUSSION We obtain a specific metabolic signature related to Tyr and Phe concentrations. We confirmed the involvement of different pathophysiological mechanisms previously described in PKU such as protein synthesis, energetic metabolism and oxidative stress. The metabolomics approach is relevant to explore PKU pathogenesis.
Collapse
|
8
|
Rajakulendran S, Pitceathly RDS, Taanman JW, Costello H, Sweeney MG, Woodward CE, Jaunmuktane Z, Holton JL, Jacques TS, Harding BN, Fratter C, Hanna MG, Rahman S. A Clinical, Neuropathological and Genetic Study of Homozygous A467T POLG-Related Mitochondrial Disease. PLoS One 2016; 11:e0145500. [PMID: 26735972 PMCID: PMC4703200 DOI: 10.1371/journal.pone.0145500] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 12/06/2015] [Indexed: 02/06/2023] Open
Abstract
Mutations in the nuclear gene POLG (encoding the catalytic subunit of DNA polymerase gamma) are an important cause of mitochondrial disease. The most common POLG mutation, A467T, appears to exhibit considerable phenotypic heterogeneity. The mechanism by which this single genetic defect results in such clinical diversity remains unclear. In this study we evaluate the clinical, neuropathological and mitochondrial genetic features of four unrelated patients with homozygous A467T mutations. One patient presented with the severe and lethal Alpers-Huttenlocher syndrome, which was confirmed on neuropathology, and was found to have a depletion of mitochondrial DNA (mtDNA). Of the remaining three patients, one presented with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS), one with a phenotype in the Myoclonic Epilepsy, Myopathy and Sensory Ataxia (MEMSA) spectrum and one with Sensory Ataxic Neuropathy, Dysarthria and Ophthalmoplegia (SANDO). All three had secondary accumulation of multiple mtDNA deletions. Complete sequence analysis of muscle mtDNA using the MitoChip resequencing chip in all four cases demonstrated significant variation in mtDNA, including a pathogenic MT-ND5 mutation in one patient. These data highlight the variable and overlapping clinical and neuropathological phenotypes and downstream molecular defects caused by the A467T mutation, which may result from factors such as the mtDNA genetic background, nuclear genetic modifiers and environmental stressors.
Collapse
Affiliation(s)
- Sanjeev Rajakulendran
- UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery and the MRC Centre for Neuromuscular Diseases, Queen Square, London WC1N 3BG, United Kingdom
| | - Robert D. S. Pitceathly
- UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, United Kingdom and Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London SE5 8AF, United Kingdom
| | - Jan-Willem Taanman
- Department of Clinical Neurosciences, UCL Institute of Neurology, London NW3 2PF, United Kingdom
| | - Harry Costello
- Mitochondrial Research Group, Genetics and Genomic Medicine, UCL Institute of Child Health, London WC1N 1EH, United Kingdom
| | - Mary G. Sweeney
- Department of Neurogenetics, UCL Institute of Neurology and National Hospital for Neurology, Queen Square, London WC1N 3BG, United Kingdom
| | - Cathy E. Woodward
- Department of Neurogenetics, UCL Institute of Neurology and National Hospital for Neurology, Queen Square, London WC1N 3BG, United Kingdom
| | - Zane Jaunmuktane
- Division of Neuropathology, UCL Institute of Neurology and National Hospital for Neurology, Queen Square, London WC1N 3BG, United Kingdom
| | - Janice L. Holton
- Division of Neuropathology, UCL Institute of Neurology and National Hospital for Neurology, Queen Square, London WC1N 3BG, United Kingdom
| | - Thomas S. Jacques
- Developmental Biology and Cancer Programme, UCL Institute of Child Health and Department of Histopathology, Great Ormond Street Hospital for Children Foundation Trust, London WC1N 1EH, United Kingdom
| | - Brian N. Harding
- Division of Neuropathology, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Carl Fratter
- Oxford Medical Genetics Laboratories, Oxford University Hospitals NHS Trust, Churchill Hospital, Oxford OX3 7LE, United Kingdom
| | - Michael G. Hanna
- UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery and the MRC Centre for Neuromuscular Diseases, Queen Square, London WC1N 3BG, United Kingdom
| | - Shamima Rahman
- Mitochondrial Research Group, Genetics and Genomic Medicine, UCL Institute of Child Health, London WC1N 1EH, United Kingdom
- Metabolic Unit, Great Ormond Street Hospital, London WC1N 3JH, United Kingdom
- * E-mail:
| |
Collapse
|
9
|
Schuck PF, Malgarin F, Cararo JH, Cardoso F, Streck EL, Ferreira GC. Phenylketonuria Pathophysiology: on the Role of Metabolic Alterations. Aging Dis 2015; 6:390-9. [PMID: 26425393 DOI: 10.14336/ad.2015.0827] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 08/27/2015] [Indexed: 11/01/2022] Open
Abstract
Phenylketonuria (PKU) is an inborn error of phenylalanine (Phe) metabolism caused by the deficiency of phenylalanine hydroxylase. This deficiency leads to the accumulation of Phe and its metabolites in tissues and body fluids of PKU patients. The main signs and symptoms are found in the brain but the pathophysiology of this disease is not well understood. In this context, metabolic alterations such as oxidative stress, mitochondrial dysfunction, and impaired protein and neurotransmitters synthesis have been described both in animal models and patients. This review aims to discuss the main metabolic disturbances reported in PKU and relate them with the pathophysiology of this disease. The elucidation of the pathophysiology of brain damage found in PKU patients will help to develop better therapeutic strategies to improve quality of life of patients affected by this condition.
Collapse
Affiliation(s)
- Patrícia Fernanda Schuck
- 1 Laboratório de Erros Inatos do Metabolismo, Unidade Acadêmica de Ciências da Saúde, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil
| | - Fernanda Malgarin
- 1 Laboratório de Erros Inatos do Metabolismo, Unidade Acadêmica de Ciências da Saúde, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil
| | - José Henrique Cararo
- 1 Laboratório de Erros Inatos do Metabolismo, Unidade Acadêmica de Ciências da Saúde, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil
| | - Fabiola Cardoso
- 2 Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Emilio Luiz Streck
- 3 Laboratório de Bioenergética, Unidade Acadêmica de Ciências da Saúde, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil
| | - Gustavo Costa Ferreira
- 2 Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| |
Collapse
|
10
|
Rocha JC, Martins MJ. Oxidative stress in phenylketonuria: future directions. J Inherit Metab Dis 2012; 35:381-98. [PMID: 22116469 DOI: 10.1007/s10545-011-9417-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 10/24/2011] [Accepted: 10/28/2011] [Indexed: 01/11/2023]
Abstract
Phenylketonuria represents the most prevalent inborn error of amino acid metabolism. In early diagnosed patients adequate and continued dietary treatment results in a good neurologic outcome. Natural protein and phenylalanine-restricted diet, even if rich in fruits and vegetables, represents a serious risk for nutritional deficiencies, albeit universally accepted. In the last few years, a growing number of reports have been describing oxidative stress as a concern in phenylketonuric patients. The diet itself includes good sources of dietary antioxidants (phytochemicals, some vitamins and minerals) but also a risk factor for some deficiencies (selenium, zinc, ubiquinone-10 and L-carnitine). Additionally, the extreme stringency of the diet may impose a reduced synthesis of endogenous antioxidants (like ubiquinone-10 and glutathione). Furthermore, increased phenylalanine levels, and its metabolites, may enhance the endogenous synthesis of reactive species and free radicals and/or interfere with the endogenous synthesis of enzymatic antioxidants (like glutathione peroxidase). Therefore, oxidative stress will probably increase, mainly in late diagnosed patients or in those with bad metabolic control. Considering the known association between oxidative stress, obesity and cardiovascular disease, it seems advisable to look further to the impact of oxidative stress on body macromolecules and structures (like lipoprotein oxidation), especially in phenylketonuric patients with late diagnosis or bad metabolic control, in order to prevent future increased risks. Recommendations for PKU patient's clinical follow-up improvement and educational goals are included.
Collapse
Affiliation(s)
- Júlio César Rocha
- Centro de Genética Médica Jacinto de Magalhães - INSA, IP, Praça Pedro Nunes, 88, 4099-028 Porto, Portugal.
| | | |
Collapse
|
11
|
Coenzyme q10 ameliorates ultraviolet B irradiation induced cell death through inhibition of mitochondrial intrinsic cell death pathway. Int J Mol Sci 2011; 12:8302-15. [PMID: 22174665 PMCID: PMC3233471 DOI: 10.3390/ijms12118302] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 10/08/2011] [Accepted: 11/21/2011] [Indexed: 12/13/2022] Open
Abstract
Ultraviolet B (UVB) induces cell death by increasing free radical production, activating apoptotic cell death pathways and depolarizing mitochondrial membrane potential. Coenzyme Q10 (CoQ10), an essential cofactor in the mitochondrial electron transport chain, serves as a potent antioxidant in the mitochondria. The aim of the present study is to establish whether CoQ10 is capable of protecting neuronal cells against UVB-induced damage. Murine hippocampal HT22 cells were treated with 0.01, 0.1 or 1 μM of CoQ10 3 or 24 h prior to the cells being exposed to UVB irradiation. The CoQ10 concentrations were maintained during irradiation and 24 h post-UVB. Cell viability was assessed by counting viable cells and MTT conversion assay. Superoxide production and mitochondrial membrane potential were measured using fluorescent probes. Levels of cleaved caspase-9, caspase-3, and apoptosis-inducing factor (AIF) were detected using immunocytochemistry and Western blotting. The results showed that UVB irradiation decreased cell viability and such damaging effect was associated with increased superoxide production, mitochondrial depolarization, and activation of caspase-9 and caspase-3. Treatment with CoQ10 at three different concentrations started 24 h before UVB exposure significantly increased the cell viability. The protective effect of CoQ10 was associated with reduction in superoxide production, normalization of mitochondrial membrane potential and inhibition of caspase-9 and caspase-3 activation. It is concluded that the neuroprotective effect of CoQ10 results from inhibiting oxidative stress and blocking caspase-3 dependent cell death pathway.
Collapse
|
12
|
Kyprianou N, Murphy E, Lee P, Hargreaves I. Assessment of mitochondrial respiratory chain function in hyperphenylalaninaemia. J Inherit Metab Dis 2009; 32:289-96. [PMID: 19277893 DOI: 10.1007/s10545-009-1080-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Revised: 01/12/2009] [Accepted: 01/14/2009] [Indexed: 11/30/2022]
Abstract
Phenylketonuria (PKU) is an autosomal recessive disorder resulting in neurological and intellectual disability when untreated. However, even in treated patients there may be residual neurological impairment such as tremor. It has been suggested that the hyperphenylalaninaemia in patients with PKU reduces complex I (NADH:ubiquinone reductase) activity of the mitochondrial respiratory chain (MRC) and/or biosynthesis of coenzyme Q(10) (CoQ(10)), which acts as an electron carrier in the MRC, leading to impaired energy metabolism in the brain of patients with PKU and hence the neurological pathology. The aim of this study was to elucidate the mechanism of phenylalanine (Phe) toxicity on the MRC. We compared mean plasma and blood-spot Phe and mononuclear CoQ(10) levels in 17 patients with PKU and a tremor compared to 22 patients without tremor. Human 1321N1 astrocytoma cells were exposed to hyperphenylalaninaemia by the addition of 300 or 900 micromol/L of Phe to the cell culture medium. Following 96 h of culture we measured complex I and citrate synthase activities and CoQ(10) level. Results showed no significant difference in Phe or CoQ(10) levels in patients with tremor compared to those without tremor. Further, hyperphenylalaninaemia did not cause a significant reduction in complex I activity or CoQ(10) biosynthesis, even when taking into account the mitochondrial enrichment of the cell samples by expressing complex I and CoQ(10) as a ratio to citrate synthase. In conclusion, the results of this study suggest that hyperphenylalaninaemia does not contribute to the pathophysiology of PKU by causing a decrease in MRC complex I activity and/or CoQ(10) biosynthesis.
Collapse
|
13
|
Hargreaves IP. Coenzyme Q10 in phenylketonuria and mevalonic aciduria. Mitochondrion 2007; 7 Suppl:S175-80. [PMID: 17442628 DOI: 10.1016/j.mito.2007.02.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Revised: 02/01/2007] [Accepted: 02/18/2007] [Indexed: 10/23/2022]
Abstract
Mevalonic aciduria (MVA) and phenylketonuria (PKU) are inborn errors of metabolism caused by deficiencies in the enzymes mevalonate kinase and phenylalanine 4-hydroxylase, respectively. Despite numerous studies the factors responsible for the pathogenicity of these disorders remain to be fully characterised. In common with MVA, a deficit in coenzyme Q10 (CoQ10) concentration has been implicated in the pathophysiology of PKU. In MVA the decrease in CoQ10 concentration may be attributed to a deficiency in mevalonate kinase, an enzyme common to both CoQ10 and cholesterol synthesis. However, although dietary sources of cholesterol cannot be excluded, the low/normal cholesterol levels in MVA patients suggests that some other factor may also be contributing to the decrease in CoQ10.The main factor associated with the low CoQ10 level of PKU patients is purported to be the elevated phenylalanine level. Phenylalanine has been shown to inhibit the activities of both 3-hydroxy-3-methylglutaryl-CoA reductase and mevalonate-5-pyrophosphate decarboxylase, enzymes common to both cholesterol and CoQ10 biosynthesis. Although evidence of a lowered plasma/serum CoQ10 level has been reported in MVA and PKU, few studies have assessed the intracellular CoQ10 concentration of patients. Plasma/serum CoQ10 is influenced by dietary intake as well as its lipoprotein content and therefore may be limited as a means of assessing intracellular CoQ10 concentration. Whether the pathogenesis of MVA and PKU are related to a loss of CoQ10 has yet to be established and further studies are required to assess the intracellular CoQ10 concentration of patients before this relationship can be confirmed or refuted.
Collapse
Affiliation(s)
- Iain P Hargreaves
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK.
| |
Collapse
|
14
|
Abstract
The HMG-CoA reductase inhibitors, also known as statins, have an enviable safety profile; however, myotoxicity and to a lesser extent hepatotoxicity have been noted in some patients following treatment. Statins target several tissues, depending upon their lipophilicity, where they competitively inhibit HMG-CoA reductase, the rate-limiting enzyme for mevalonic acid synthesis and subsequently cholesterol biosynthesis. HMG-CoA reductase is also the first committed rate-limiting step for the synthesis of a range of other compounds including steroid hormones and ubidecarenone (ubiquinone), otherwise known as coenzyme Q(10) (CoQ(10)). Recent interest has focused on the possible role CoQ(10) deficiency may have in the pathophysiology of the rare adverse effects of statin treatment. Currently, there is insufficient evidence from human studies to link statin therapy unequivocally to pathologically significantly decreased tissue CoQ(10) levels. Although statin treatment has been reported to lower plasma/serum CoQ(10) status, few human studies have assessed tissue CoQ(10) status. The plasma/serum CoQ(10) level is influenced by a number of physiological factors and, therefore, has limited value as a means of assessing intracellular CoQ(10) status. In those limited studies that have assessed the effect of statin treatment upon tissue CoQ(10) levels, none have shown evidence of a fall in CoQ(10) levels. This may reflect the doses of statins used, since many appear to have been used at doses below those recommended for their maximum therapeutic effects. Moreover, the poor bioavailability in those peripheral tissues tested may not reflect the effects the agents are having in liver and muscle, the tissues commonly affected in those patients who do not tolerate statins. This article reviews the biochemistry of CoQ(10), its role in cellular metabolism and the available evidence linking possible CoQ(10) deficiency to statin therapy.
Collapse
Affiliation(s)
- Iain P Hargreaves
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK.
| | | | | | | |
Collapse
|
15
|
Silver RC. Conducting research after the 9/11 terrorist attacks: Challenges and results. ACTA ACUST UNITED AC 2004. [DOI: 10.1037/1091-7527.22.1.47] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
16
|
Artuch R, Vilaseca MA, Lambruschini N, Campistol J. Coenzyme-Q(10) concentration in human phenylketonuria. J Inherit Metab Dis 2003; 26:821-3; author response 823. [PMID: 14765535 DOI: 10.1023/b:boli.0000010007.16830.0b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|