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Wu Q, Ren Q, Meng J, Gao WJ, Chang YZ. Brain Iron Homeostasis and Mental Disorders. Antioxidants (Basel) 2023; 12:1997. [PMID: 38001850 PMCID: PMC10669508 DOI: 10.3390/antiox12111997] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 10/30/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
Iron plays an essential role in various physiological processes. A disruption in iron homeostasis can lead to severe consequences, including impaired neurodevelopment, neurodegenerative disorders, stroke, and cancer. Interestingly, the link between mental health disorders and iron homeostasis has not received significant attention. Therefore, our understanding of iron metabolism in the context of psychological diseases is incomplete. In this review, we aim to discuss the pathologies and potential mechanisms that relate to iron homeostasis in associated mental disorders. We propose the hypothesis that maintaining brain iron homeostasis can support neuronal physiological functions by impacting key enzymatic activities during neurotransmission, redox balance, and myelination. In conclusion, our review highlights the importance of investigating the relationship between trace element nutrition and the pathological process of mental disorders, focusing on iron. This nutritional perspective can offer valuable insights for the clinical treatment of mental disorders.
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Affiliation(s)
- Qiong Wu
- Hebei Key Laboratory of Chinese Medicine Research on Cardio-Cerebrovascular Disease, Hebei University of Chinese Medicine, Shijiazhuang 050200, China;
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, The Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, No. 20 Nan’erhuan Eastern Road, Shijiazhuang 050024, China; (Q.R.); (J.M.)
| | - Qiuyang Ren
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, The Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, No. 20 Nan’erhuan Eastern Road, Shijiazhuang 050024, China; (Q.R.); (J.M.)
| | - Jingsi Meng
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, The Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, No. 20 Nan’erhuan Eastern Road, Shijiazhuang 050024, China; (Q.R.); (J.M.)
| | - Wei-Juan Gao
- Hebei Key Laboratory of Chinese Medicine Research on Cardio-Cerebrovascular Disease, Hebei University of Chinese Medicine, Shijiazhuang 050200, China;
| | - Yan-Zhong Chang
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, The Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, No. 20 Nan’erhuan Eastern Road, Shijiazhuang 050024, China; (Q.R.); (J.M.)
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2
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Lotan A, Luza S, Opazo CM, Ayton S, Lane DJR, Mancuso S, Pereira A, Sundram S, Weickert CS, Bousman C, Pantelis C, Everall IP, Bush AI. Perturbed iron biology in the prefrontal cortex of people with schizophrenia. Mol Psychiatry 2023; 28:2058-2070. [PMID: 36750734 PMCID: PMC10575779 DOI: 10.1038/s41380-023-01979-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 01/10/2023] [Accepted: 01/20/2023] [Indexed: 02/09/2023]
Abstract
Despite loss of grey matter volume and emergence of distinct cognitive deficits in young adults diagnosed with schizophrenia, current treatments for schizophrenia do not target disruptions in late maturational reshaping of the prefrontal cortex. Iron, the most abundant transition metal in the brain, is essential to brain development and function, but in excess, it can impair major neurotransmission systems and lead to lipid peroxidation, neuroinflammation and accelerated aging. However, analysis of cortical iron biology in schizophrenia has not been reported in modern literature. Using a combination of inductively coupled plasma-mass spectrometry and western blots, we quantified iron and its major-storage protein, ferritin, in post-mortem prefrontal cortex specimens obtained from three independent, well-characterised brain tissue resources. Compared to matched controls (n = 85), among schizophrenia cases (n = 86) we found elevated tissue iron, unlikely to be confounded by demographic and lifestyle variables, by duration, dose and type of antipsychotic medications used or by copper and zinc levels. We further observed a loss of physiologic age-dependent iron accumulation among people with schizophrenia, in that the iron level among cases was already high in young adulthood. Ferritin, which stores iron in a redox-inactive form, was paradoxically decreased in individuals with the disorder. Such iron-ferritin uncoupling could alter free, chemically reactive, tissue iron in key reasoning and planning areas of the young-adult schizophrenia cortex. Using a prediction model based on iron and ferritin, our data provide a pathophysiologic link between perturbed cortical iron biology and schizophrenia and indicate that achievement of optimal cortical iron homeostasis could offer a new therapeutic target.
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Affiliation(s)
- Amit Lotan
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, 3010, Australia
- Department of Psychiatry and the Biological Psychiatry Laboratory, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Sandra Luza
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, 3010, Australia
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne & Melbourne Health, Carlton, VIC, Australia
| | - Carlos M Opazo
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, 3010, Australia.
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne & Melbourne Health, Carlton, VIC, Australia.
| | - Scott Ayton
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Darius J R Lane
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Serafino Mancuso
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne & Melbourne Health, Carlton, VIC, Australia
| | - Avril Pereira
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, 3010, Australia
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne & Melbourne Health, Carlton, VIC, Australia
| | - Suresh Sundram
- Department of Psychiatry, School of Clinical Sciences, Monash University, Melbourne, VIC, Australia
- Mental Health Program, Monash Health, Melbourne, VIC, Australia
| | - Cynthia Shannon Weickert
- Schizophrenia Research Laboratory, Neuroscience Research Australia, Randwick, NSW, Australia
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Chad Bousman
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne & Melbourne Health, Carlton, VIC, Australia
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Departments of Medical Genetics, Psychiatry, Physiology & Pharmacology, University of Calgary, Calgary, AB, Canada
- The Cooperative Research Centre (CRC) for Mental Health, Melbourne, VIC, Australia
| | - Christos Pantelis
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne & Melbourne Health, Carlton, VIC, Australia
- North Western Mental Health, Melbourne, VIC, Australia
| | - Ian P Everall
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne & Melbourne Health, Carlton, VIC, Australia
- North Western Mental Health, Melbourne, VIC, Australia
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Ashley I Bush
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, 3010, Australia.
- The Cooperative Research Centre (CRC) for Mental Health, Melbourne, VIC, Australia.
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3
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Dong S, Gu G, Lin T, Wang Z, Li J, Tan K, Nieh JC. An inhibitory signal associated with danger reduces honeybee dopamine levels. Curr Biol 2023; 33:2081-2087.e4. [PMID: 37059097 DOI: 10.1016/j.cub.2023.03.072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/20/2023] [Accepted: 03/24/2023] [Indexed: 04/16/2023]
Abstract
Positive and negative experiences can alter animal brain dopamine levels.1 When first arriving at a rewarding food source or beginning to waggle dance and recruit nestmates to food, honeybees have increased brain dopamine levels, indicating a desire for food.2 We provide the first evidence that an inhibitory signal, the stop signal, which counters waggle dancing and is triggered by negative events at the food source, can decrease head dopamine levels and dancing, independent of the dancer having any negative experiences. The hedonic value of food can therefore be depressed simply by the receipt of an inhibitory signal. Increasing the brain dopamine levels reduced the aversive effects of an attack, increasing the time that bees spent subsequently feeding and waggle dancing and decreasing their stop signaling and time spent in the hive. Because honeybees regulate food recruitment and its inhibition at the colony level, these results highlight the complex integration of colony information with a basic and highly conserved neural mechanism in mammals and insects.2 VIDEO ABSTRACT.
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Affiliation(s)
- Shihao Dong
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650000, China
| | - Gaoying Gu
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tao Lin
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650000, China
| | - Ziqi Wang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianjun Li
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650000, China
| | - Ken Tan
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650000, China.
| | - James C Nieh
- School of Biological Sciences, Department of Ecology, Behavior, and Evolution, University of California, San Diego, La Jolla, CA 92093, USA.
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4
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Fitzpatrick PF. The aromatic amino acid hydroxylases: Structures, catalysis, and regulation of phenylalanine hydroxylase, tyrosine hydroxylase, and tryptophan hydroxylase. Arch Biochem Biophys 2023; 735:109518. [PMID: 36639008 DOI: 10.1016/j.abb.2023.109518] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 01/01/2023] [Accepted: 01/06/2023] [Indexed: 01/12/2023]
Abstract
The aromatic amino acid hydroxylases phenylalanine hydroxylase, tyrosine hydroxylase, and tryptophan hydroxylase are non-heme iron enzymes that catalyze key physiological reactions. This review discusses the present understanding of the common catalytic mechanism of these enzymes and recent advances in understanding the relationship between their structures and their regulation.
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Affiliation(s)
- Paul F Fitzpatrick
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, 78229, USA.
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5
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Ravanfar P, Syeda WT, Jayaram M, Rushmore RJ, Moffat B, Lin AP, Lyall AE, Merritt AH, Yaghmaie N, Laskaris L, Luza S, Opazo CM, Liberg B, Chakravarty MM, Devenyi GA, Desmond P, Cropley VL, Makris N, Shenton ME, Bush AI, Velakoulis D, Pantelis C. In Vivo 7-Tesla MRI Investigation of Brain Iron and Its Metabolic Correlates in Chronic Schizophrenia. SCHIZOPHRENIA (HEIDELBERG, GERMANY) 2022; 8:86. [PMID: 36289238 PMCID: PMC9605948 DOI: 10.1038/s41537-022-00293-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Brain iron is central to dopaminergic neurotransmission, a key component in schizophrenia pathology. Iron can also generate oxidative stress, which is one proposed mechanism for gray matter volume reduction in schizophrenia. The role of brain iron in schizophrenia and its potential link to oxidative stress has not been previously examined. In this study, we used 7-Tesla MRI quantitative susceptibility mapping (QSM), magnetic resonance spectroscopy (MRS), and structural T1 imaging in 12 individuals with chronic schizophrenia and 14 healthy age-matched controls. In schizophrenia, there were higher QSM values in bilateral putamen and higher concentrations of phosphocreatine and lactate in caudal anterior cingulate cortex (caCC). Network-based correlation analysis of QSM across corticostriatal pathways as well as the correlation between QSM, MRS, and volume, showed distinct patterns between groups. This study introduces increased iron in the putamen in schizophrenia in addition to network-wide disturbances of iron and metabolic status.
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Affiliation(s)
- Parsa Ravanfar
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia.
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
| | - Warda T Syeda
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia
| | - Mahesh Jayaram
- Department of Psychiatry, The University of Melbourne and Melbourne Health, Parkville, Australia
| | - R Jarrett Rushmore
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Center for Morphometric Analysis (CMA), Massachusetts General Hospital, Charlestown, MA, USA
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, USA
| | - Bradford Moffat
- Melbourne Brain Centre Imaging Unit, Department of Radiology, University of Melbourne, Parkville, VIC, Australia
| | - Alexander P Lin
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Amanda E Lyall
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Antonia H Merritt
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia
| | - Negin Yaghmaie
- Melbourne Brain Centre Imaging Unit, Department of Radiology, University of Melbourne, Parkville, VIC, Australia
- Department of Biomedical Engineering, The University of Melbourne, Parkville, VIC, Australia
| | - Liliana Laskaris
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia
| | - Sandra Luza
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia
- Melbourne Dementia Research Centre, The Florey Institute of Neuroscience & Mental Health, and The University of Melbourne, Parkville, VIC, Australia
| | - Carlos M Opazo
- Melbourne Dementia Research Centre, The Florey Institute of Neuroscience & Mental Health, and The University of Melbourne, Parkville, VIC, Australia
| | - Benny Liberg
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - M Mallar Chakravarty
- Cerebral Imaging Center, Douglas Research Centre, Montreal, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
- Department of Biomedical Engineering, McGill University, Montreal, QC, Canada
| | - Gabriel A Devenyi
- Cerebral Imaging Center, Douglas Research Centre, Montreal, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Patricia Desmond
- Department of Radiology, Royal Melbourne Hospital, University of Melbourne, Parkville, VIC, Australia
| | - Vanessa L Cropley
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia
| | - Nikos Makris
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Center for Morphometric Analysis (CMA), Massachusetts General Hospital, Charlestown, MA, USA
| | - Martha E Shenton
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Ashley I Bush
- Melbourne Dementia Research Centre, The Florey Institute of Neuroscience & Mental Health, and The University of Melbourne, Parkville, VIC, Australia
| | - Dennis Velakoulis
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia
- Neuropsychiatry, The Royal Melbourne Hospital, Parkville, VIC, Australia
| | - Christos Pantelis
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia.
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia.
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6
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Berthou C, Iliou JP, Barba D. Iron, neuro‐bioavailability and depression. EJHAEM 2022; 3:263-275. [PMID: 35846210 PMCID: PMC9175715 DOI: 10.1002/jha2.321] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 10/05/2021] [Accepted: 10/05/2021] [Indexed: 12/14/2022]
Abstract
Medical management of iron deficiency (ID) requires to consider its consequences in biochemical and physiological plural functions, beyond heme/hemoglobin disrupted synthesis. Fatigue, muscle weakness, reduced exercise capacity, changes in thymia and modified emotional behaviors are the commonest symptoms integrated in the history of ID, dependent or not of the hemoglobin concentration. The relationship between depression and absolute ID (AID) is a condition which is often unrecognized. Neuro‐bioavailability and brain capture of blood iron are necessary for an appropriate synthesis of neurotransmitters (serotonin, dopamine, noradrenaline). These neurotransmitters, involved in emotional behaviors, depend on neuron aromatic hydoxylases functioning with iron as essential cofactor. Noradrenaline also has impact on neuroplasticity via brain‐derived neurotrophic factor (BDNF), which is key for prefrontal and hippocampus neurons playing a role in depression. Establishing the formal relationship between depression and AID remains difficult. Intracerebral reduced iron is still hard to quantify by neuroimaging and single‐photon emission computed tomography (SPECT) now tends to explore the neurotransmission pathways. AID has to be looked for and identified in the context of depression, major episode or resistant to conventional treatment such as serotonin reuptake inhibitor, and even in the absence of anemia, microcytosis or hypochromia (non‐anemic ID). Confronted to brain imaging, blood iron status evaluation is indicated, especially in depressed, treatment‐resistant, iron‐deficient young women. In patients suffering from depression, increase in the prevalence of AID should be considered, in order to deliver a suitable treatment, considering both anti‐depressive program and iron supplementation if AID.
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Affiliation(s)
- Christian Berthou
- Department of Immuno‐Hematology INSERM UMR 12 27 LBAI University Brest Brest France
| | | | - Denis Barba
- Health and Medical Center Le Guilvinec France
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7
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Bueno-Carrasco MT, Cuéllar J, Flydal MI, Santiago C, Kråkenes TA, Kleppe R, López-Blanco JR, Marcilla M, Teigen K, Alvira S, Chacón P, Martinez A, Valpuesta JM. Structural mechanism for tyrosine hydroxylase inhibition by dopamine and reactivation by Ser40 phosphorylation. Nat Commun 2022; 13:74. [PMID: 35013193 PMCID: PMC8748767 DOI: 10.1038/s41467-021-27657-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 12/03/2021] [Indexed: 12/15/2022] Open
Abstract
Tyrosine hydroxylase (TH) catalyzes the rate-limiting step in the biosynthesis of dopamine (DA) and other catecholamines, and its dysfunction leads to DA deficiency and parkinsonisms. Inhibition by catecholamines and reactivation by S40 phosphorylation are key regulatory mechanisms of TH activity and conformational stability. We used Cryo-EM to determine the structures of full-length human TH without and with DA, and the structure of S40 phosphorylated TH, complemented with biophysical and biochemical characterizations and molecular dynamics simulations. TH presents a tetrameric structure with dimerized regulatory domains that are separated 15 Å from the catalytic domains. Upon DA binding, a 20-residue α-helix in the flexible N-terminal tail of the regulatory domain is fixed in the active site, blocking it, while S40-phosphorylation forces its egress. The structures reveal the molecular basis of the inhibitory and stabilizing effects of DA and its counteraction by S40-phosphorylation, key regulatory mechanisms for homeostasis of DA and TH. Tyrosine hydroxylase (TH) catalyzes the rate-limiting step in the synthesis of the catecholamine neurotransmitters and hormones dopamine (DA), adrenaline and noradrenaline. Here, the authors present the cryo-EM structures of full-length human TH in the apo form and bound with DA, as well as the structure of Ser40 phosphorylated TH, and discuss the inhibitory and stabilizing effects of DA on TH and its counteraction by Ser40-phosphorylation.
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Affiliation(s)
| | - Jorge Cuéllar
- Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain.
| | - Marte I Flydal
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - César Santiago
- Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
| | | | - Rune Kleppe
- Norwegian Centre for Maritime and Diving Medicine, Department of Occupational Medicine, Haukeland University Hospital, Bergen, Norway
| | | | | | - Knut Teigen
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Sara Alvira
- Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain.,School of Biochemistry, University of Bristol, Bristol, BS8 1TD, UK
| | - Pablo Chacón
- Instituto de Química Física Rocasolano (IQFR-CSIC), Madrid, Spain
| | - Aurora Martinez
- Department of Biomedicine, University of Bergen, Bergen, Norway.
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8
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Cannon Homaei S, Barone H, Kleppe R, Betari N, Reif A, Haavik J. ADHD symptoms in neurometabolic diseases: Underlying mechanisms and clinical implications. Neurosci Biobehav Rev 2021; 132:838-856. [PMID: 34774900 DOI: 10.1016/j.neubiorev.2021.11.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/09/2021] [Accepted: 11/09/2021] [Indexed: 12/16/2022]
Abstract
Neurometabolic diseases (NMDs) are typically caused by genetic abnormalities affecting enzyme functions, which in turn interfere with normal development and activity of the nervous system. Although the individual disorders are rare, NMDs are collectively relatively common and often lead to lifelong difficulties and high societal costs. Neuropsychiatric manifestations, including ADHD symptoms, are prominent in many NMDs, also when the primary biochemical defect originates in cells and tissues outside the nervous system. ADHD symptoms have been described in phenylketonuria, tyrosinemias, alkaptonuria, succinic semialdehyde dehydrogenase deficiency, X-linked ichthyosis, maple syrup urine disease, and several mitochondrial disorders, but are probably present in many other NMDs and may pose diagnostic and therapeutic challenges. Here we review current literature linking NMDs with ADHD symptoms. We cite emerging evidence that many NMDs converge on common neurochemical mechanisms that interfere with monoamine neurotransmitter synthesis, transport, metabolism, or receptor functions, mechanisms that are also considered central in ADHD pathophysiology and treatment. Finally, we discuss the therapeutic implications of these findings and propose a path forward to increase our understanding of these relationships.
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Affiliation(s)
- Selina Cannon Homaei
- Division of Psychiatry, Haukeland University Hospital, Norway; Department of Biomedicine, University of Bergen, Norway.
| | - Helene Barone
- Regional Resource Center for Autism, ADHD, Tourette Syndrome and Narcolepsy, Western Norway, Division of Psychiatry, Haukeland University Hospital, Norway.
| | - Rune Kleppe
- Division of Psychiatry, Haukeland University Hospital, Norway; Norwegian Centre for Maritime and Diving Medicine, Department of Occupational Medicine, Haukeland University Hospital, Norway.
| | - Nibal Betari
- Department of Biomedicine, University of Bergen, Norway.
| | - Andreas Reif
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital Frankfurt, Frankfurt am Main, Germany.
| | - Jan Haavik
- Division of Psychiatry, Haukeland University Hospital, Norway; Department of Biomedicine, University of Bergen, Norway.
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9
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Surowka AD, Czyzycki M, Ziomber-Lisiak A, Migliori A, Szczerbowska-Boruchowska M. On 2D-FTIR-XRF microscopy - A step forward correlative tissue studies by infrared and hard X-ray radiation. Ultramicroscopy 2021; 232:113408. [PMID: 34706307 DOI: 10.1016/j.ultramic.2021.113408] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 09/14/2021] [Accepted: 10/03/2021] [Indexed: 11/28/2022]
Abstract
Correlative Fourier Transform Infra-Red (FTIR) and hard X-Ray Fluorescence (XRF) microscopy studies of thin biological samples have recently evolved as complementary methods for biochemical fingerprinting of animal/human tissues. These are seen particularly useful for tracking the mechanisms of neurological diseases, i.e., in Alzheimer/Parkinson disease, in the brain where mishandling of trace metals (Fe, Cu, Zn) seems to be often associated with ongoing damage to molecular components via, among others, oxidative/reductive stress neurotoxicity. Despite substantial progress in state-of-the-art detection and data analysis methods, combined FTIR-XRF experiments have never benefited from correlation and co-localization analysis of molecular moieties and chemical elements, respectively. We here propose for the first time a completely novel data analysis pipeline, utilizing the idea of 2D correlation spectrometry for brain tissue analysis. In this paper, we utilized combined benchtop FTIR - synchrotron XRF mapping experiments on thin brain samples mounted on polypropylene membranes. By implementing our recently developed Multiple Linear Regression Multi-Reference (MLR-MR) algorithm, along with advanced image processing, artifact-free 2D FTIR-XRF spectra could be obtained by mitigating the impact of spectral artifacts, such as Etalon fringes and mild scattering Mie-like signatures, in the FTIR data. We demonstrated that the method is a powerful tool for co-localizing and correlating molecular arrangements and chemical elements (and vice versa) using visually attractive 2D correlograms. Moreover, the methods' applicability for fostering the identification of distinct (biological) materials, involving chemical elements and molecular arrangements, is also shown. Taken together, the 2D FTIR-XRF method opens up for new measures for in-situ investigating hidden complex biochemical correlations, and yet unraveled mechanisms in a biological sample. This step seems crucial for developing new strategies for facilitating the research on the interaction of metals/nonmetals with organic components. This is particularly important for enhancing our understanding of the diseases associated with metal/nonmetal mishandling.
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Affiliation(s)
- Artur D Surowka
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. A. Mickiewicza 30, Krakow 30-059, Poland.
| | - Mateusz Czyzycki
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. A. Mickiewicza 30, Krakow 30-059, Poland; Laboratory for Applications of Synchrotron Radiation, Karlsruhe Institute of Technology, Kaiser Str. 12, Karlsruhe 76131, Germany; Nuclear Science and Instrumentation Laboratory, International Atomic Energy Agency (IAEA) Laboratories, Seibersdorf, Austria
| | - Agata Ziomber-Lisiak
- Department of Pathophysiology, Jagiellonian University, Medical College, Czysta 18, Krakow 31-121, Poland
| | - Alessandro Migliori
- Nuclear Science and Instrumentation Laboratory, International Atomic Energy Agency (IAEA) Laboratories, Seibersdorf, Austria
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10
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Discovery and biological characterization of a novel scaffold for potent inhibitors of peripheral serotonin synthesis. Future Med Chem 2020; 12:1461-1474. [DOI: 10.4155/fmc-2020-0127] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Aim: Tryptophan hydroxylase 1 (TPH1) catalyzes serotonin synthesis in peripheral tissues. Selective TPH1 inhibitors may be useful for treating disorders related to serotonin dysregulation. Results & methodology: Screening using a thermal shift assay for TPH1 binders yielded Compound 1 (2-(4-methylphenyl)-1,2-benzisothiazol-3(2 H)-one), which showed high potency (50% inhibition at 98 ± 30 nM) and selectivity for inhibiting TPH over related aromatic amino acid hydroxylases in enzyme activity assays. Structure–activity relationships studies revealed several analogs of 1 showing comparable potency. Kinetic studies suggested a noncompetitive mode of action of 1, with regards to tryptophan and tetrahydrobiopterin. Computational docking studies and live cell assays were also performed. Conclusion: This TPH1 inhibitor scaffold may be useful for developing new therapeutics for treating elevated peripheral serotonin.
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11
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Vasquez V, Mitra J, Wang H, Hegde PM, Rao KS, Hegde ML. A multi-faceted genotoxic network of alpha-synuclein in the nucleus and mitochondria of dopaminergic neurons in Parkinson's disease: Emerging concepts and challenges. Prog Neurobiol 2020; 185:101729. [PMID: 31863801 PMCID: PMC7098698 DOI: 10.1016/j.pneurobio.2019.101729] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 10/15/2019] [Accepted: 11/18/2019] [Indexed: 02/06/2023]
Abstract
α-Synuclein is a hallmark amyloidogenic protein component of the Lewy bodies (LBs) present in dopaminergic neurons affected by Parkinson's disease (PD). Despite an enormous increase in emerging knowledge, the mechanism(s) of α-synuclein neurobiology and crosstalk among pathological events that are critical for PD progression remains enigmatic, creating a roadblock for effective intervention strategies. One confounding question is about the potential link between α-synuclein toxicity and genome instability in PD. We previously reported that pro-oxidant metal ions, together with reactive oxygen species (ROS), act as a "double whammy" in dopaminergic neurons by not only inducing genome damage but also inhibiting their repair. Our recent studies identified a direct role for chromatin-bound, oxidized α-synuclein in the induction of DNA strand breaks, which raised the question of a paradoxical role for α-synuclein's DNA binding in neuroprotection versus neurotoxicity. Furthermore, recent advances in our understanding of α-synuclein mediated mitochondrial dysfunction warrants revisiting the topics of α-synuclein pathophysiology in order to devise and assess the efficacy of α-synuclein-targeted interventions. In this review article, we discuss the multi-faceted neurotoxic role of α-synuclein in the nucleus and mitochondria with a particular emphasis on the role of α-synuclein in DNA damage/repair defects. We utilized a protein-DNA binding simulation to identify potential residues in α-synuclein that could mediate its binding to DNA and may be critical for its genotoxic functions. These emerging insights and paradigms may guide new drug targets and therapeutic modalities.
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Affiliation(s)
- Velmarini Vasquez
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, 77030, USA; Centre for Neuroscience, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, City of Knowledge, Panama
| | - Joy Mitra
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - Haibo Wang
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, 77030, USA; Center for Neuroregeneration, Department of Neurosurgery, Methodist Neurological Institute, Institute of Academic Medicine, Houston Methodist Hospital, Houston, TX, 77030, USA
| | - Pavana M Hegde
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - K S Rao
- Centre for Neuroscience, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, City of Knowledge, Panama
| | - Muralidhar L Hegde
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, 77030, USA; Center for Neuroregeneration, Department of Neurosurgery, Methodist Neurological Institute, Institute of Academic Medicine, Houston Methodist Hospital, Houston, TX, 77030, USA; Weill Cornell Medical College of Cornell University, New York, 10065, USA.
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12
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Lang JA, Smaller KA. Orall-tyrosine supplementation augments the vasoconstriction response to whole-body cooling in older adults. Exp Physiol 2017; 102:835-844. [DOI: 10.1113/ep086329] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/03/2017] [Indexed: 11/08/2022]
Affiliation(s)
- James A. Lang
- Department of Physical Therapy; Des Moines University; Des Moines IA 50312 USA
| | - Kevin A. Smaller
- Department of Neuroscience; Drake University; Des Moines IA 50311 USA
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13
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Nagatsu T, Nagatsu I. Tyrosine hydroxylase (TH), its cofactor tetrahydrobiopterin (BH4), other catecholamine-related enzymes, and their human genes in relation to the drug and gene therapies of Parkinson's disease (PD): historical overview and future prospects. J Neural Transm (Vienna) 2016; 123:1255-1278. [PMID: 27491309 DOI: 10.1007/s00702-016-1596-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 07/14/2016] [Indexed: 12/21/2022]
Abstract
Tyrosine hydroxylase (TH), which was discovered at the National Institutes of Health (NIH) in 1964, is a tetrahydrobiopterin (BH4)-requiring monooxygenase that catalyzes the first and rate-limiting step in the biosynthesis of catecholamines (CAs), such as dopamine, noradrenaline, and adrenaline. Since deficiencies of dopamine and noradrenaline in the brain stem, caused by neurodegeneration of dopamine and noradrenaline neurons, are mainly related to non-motor and motor symptoms of Parkinson's disease (PD), we have studied human CA-synthesizing enzymes [TH; BH4-related enzymes, especially GTP-cyclohydrolase I (GCH1); aromatic L-amino acid decarboxylase (AADC); dopamine β-hydroxylase (DBH); and phenylethanolamine N-methyltransferase (PNMT)] and their genes in relation to PD in postmortem brains from PD patients, patients with CA-related genetic diseases, mice with genetically engineered CA neurons, and animal models of PD. We purified all human CA-synthesizing enzymes, produced their antibodies for immunohistochemistry and immunoassay, and cloned all human genes, especially the human TH gene and the human gene for GCH1, which synthesizes BH4 as a cofactor of TH. This review discusses the historical overview of TH, BH4-, and other CA-related enzymes and their genes in relation to the pathophysiology of PD, the development of drugs, such as L-DOPA, and future prospects for drug and gene therapy for PD, especially the potential of induced pluripotent stem (iPS) cells.
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Affiliation(s)
- Toshiharu Nagatsu
- Department of Pharmacology, School of Medicine, Fujita Health University, Toyoake, Aichi, 470-1192, Japan.
- Department of Brain Functions, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Aichi, 464-8601, Japan.
| | - Ikuko Nagatsu
- Department of Anatomy, School of Medicine, Fujita Health University, Toyoake, 470-1192, Japan
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14
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Krzyaniak MD, Eser BE, Ellis HR, Fitzpatrick PF, McCracken J. Pulsed EPR study of amino acid and tetrahydropterin binding in a tyrosine hydroxylase nitric oxide complex: evidence for substrate rearrangements in the formation of the oxygen-reactive complex. Biochemistry 2013; 52:8430-41. [PMID: 24168553 DOI: 10.1021/bi4010914] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tyrosine hydroxylase is a nonheme iron enzyme found in the nervous system that catalyzes the hydroxylation of tyrosine to form l-3,4-dihydroxyphenylalanine, the rate-limiting step in the biosynthesis of the catecholamine neurotransmitters. Catalysis requires the binding of three substrates: tyrosine, tetrahydrobiopterin, and molecular oxygen. We have used nitric oxide as an O₂ surrogate to poise Fe(II) at the catalytic site in an S = 3/2, {FeNO}⁷ form amenable to EPR spectroscopy. ²H-electron spin echo envelope modulation was then used to measure the distance and orientation of specifically deuterated substrate tyrosine and cofactor 6-methyltetrahydropterin with respect to the magnetic axes of the {FeNO}⁷ paramagnetic center. Our results show that the addition of tyrosine triggers a conformational change in the enzyme that reduces the distance from the {FeNO}⁷ center to the closest deuteron on 6,7-²H-6-methyltetrahydropterin from >5.9 Å to 4.4 ± 0.2 Å. Conversely, the addition of 6-methyltetrahydropterin to enzyme samples treated with 3,5-²H-tyrosine resulted in reorientation of the magnetic axes of the S = 3/2, {FeNO}⁷ center with respect to the deuterated substrate. Taken together, these results show that the coordination of both substrate and cofactor direct the coordination of NO to Fe(II) at the active site. Parallel studies of a quaternary complex of an uncoupled tyrosine hydroxylase variant, E332A, show no change in the hyperfine coupling to substrate tyrosine and cofactor 6-methyltetrahydropterin. Our results are discussed in the context of previous spectroscopic and X-ray crystallographic studies done on tyrosine hydroxylase and phenylalanine hydroxylase.
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Affiliation(s)
- Matthew D Krzyaniak
- Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States
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15
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Effect of ascorbic acid deficiency on catecholamine synthesis in adrenal glands of SMP30/GNL knockout mice. Eur J Nutr 2013; 53:177-85. [DOI: 10.1007/s00394-013-0515-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2012] [Accepted: 03/06/2013] [Indexed: 12/13/2022]
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16
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Roberts KM, Fitzpatrick PF. Mechanisms of tryptophan and tyrosine hydroxylase. IUBMB Life 2013; 65:350-7. [PMID: 23441081 DOI: 10.1002/iub.1144] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 01/02/2013] [Indexed: 11/11/2022]
Abstract
The aromatic amino acid hydroxylases tryptophan hydroxylase and tyrosine hydroxylase are responsible for the initial steps in the formation of serotonin and the catecholamine neurotransmitters, respectively. Both enzymes are nonheme iron-dependent monooxygenases that catalyze the insertion of one atom of molecular oxygen onto the aromatic ring of their amino acid substrates, using a tetrahydropterin as a two electron donor to reduce the second oxygen atom to water. This review discusses the current understanding of the catalytic mechanism of these two enzymes. The reaction occurs as two sequential half reactions: a reaction between the active site iron, oxygen, and the tetrahydropterin to form a reactive Fe(IV) O intermediate and hydroxylation of the amino acid by the Fe(IV) O. The mechanism of formation of the Fe(IV) O is unclear; however, considerable evidence suggests the formation of an Fe(II) -peroxypterin intermediate. The amino acid is hydroxylated by the Fe(IV) O intermediate in an electrophilic aromatic substitution mechanism.
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Affiliation(s)
- Kenneth M Roberts
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78228, USA
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17
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Singh M, Murthy V, Ramassamy C. Neuroprotective mechanisms of the standardized extract of Bacopa monniera in a paraquat/diquat-mediated acute toxicity. Neurochem Int 2013; 62:530-9. [PMID: 23402822 DOI: 10.1016/j.neuint.2013.01.030] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 01/23/2013] [Accepted: 01/30/2013] [Indexed: 12/28/2022]
Abstract
Parkinson's disease (PD) is one of the most common age related neurodegenerative disease and affects millions of people worldwide. Strong evidence suggests a role for oxidative stress and mitochondrial dysfunctions in the pathogenesis of PD. Recent epidemiologic and toxicological studies have shown that environmental factors, especially herbicides such as paraquat and diquat represent one of the primary classes of neurotoxic agents associated with PD. The objective of our study was to investigate the neuroprotective effects of the standardized extract of Bacopa monniera (BM) against paraquat/diquat-induced toxicity and to elucidate the mechanisms underlying this protection. Our results showed that a pre-treatment with the BM extract, from 20.0μg/ml, protected the rat dopaminergic PC12 cell line against paraquat/diquat-induced toxicity in various cell survival assays. We demonstrated that BM pre-treatment, from 5.0μg/ml, could prevent the generation of intracellular reactive oxygen species (ROS), decreased mitochondrial superoxide levels and depolarized the mitochondria. BM pre-treatment also increased tyrosine hydroxylase (TH) levels and antioxidant defense systems such as γ-glutamylcysteine synthetase (γ-GCS) and thioredoxin1 (Trx1) levels. Furthermore, BM pre-treatment prevented the activation of Akt and heat shock protein90 (HSP90) proteins. Thus, our findings demonstrated that BM can protect PC12 cells through modulating cellular redox pathways which are altered in PD and could have a therapeutic application in the prevention of PD.
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Affiliation(s)
- Manjeet Singh
- INRS - Institut Armand Frappier, Quebec, Canada H7V 1B7
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18
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Philmus B, Abdelwahed S, Williams HJ, Fenwick MK, Ealick SE, Begley TP. Identification of the product of toxoflavin lyase: degradation via a Baeyer-Villiger oxidation. J Am Chem Soc 2012; 134:5326-30. [PMID: 22304755 PMCID: PMC3332044 DOI: 10.1021/ja211759n] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Toxoflavin (an azapteridine) is degraded to a single product by toxoflavin lyase (TflA) in a reaction dependent on reductant, Mn(II), and oxygen. The isolated product was fully characterized by NMR and MS and was identified as a triazine in which the pyrimidine ring was oxidatively degraded. A mechanism for toxoflavin degradation based on the identification of the enzymatic product and the recently determined crystal structure of toxoflavin lyase is proposed.
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Affiliation(s)
- Benjamin Philmus
- Dept. of Chemistry, Texas A&M University, College Station, TX 77843
- Dept. of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
| | - Sameh Abdelwahed
- Dept. of Chemistry, Texas A&M University, College Station, TX 77843
- Dept. of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
| | - Howard J. Williams
- Dept. of Chemistry, Texas A&M University, College Station, TX 77843
- Dept. of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
| | - Michael K. Fenwick
- Dept. of Chemistry, Texas A&M University, College Station, TX 77843
- Dept. of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
| | - Steven E. Ealick
- Dept. of Chemistry, Texas A&M University, College Station, TX 77843
- Dept. of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
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19
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Fitzpatrick PF. Allosteric regulation of phenylalanine hydroxylase. Arch Biochem Biophys 2012; 519:194-201. [PMID: 22005392 PMCID: PMC3271142 DOI: 10.1016/j.abb.2011.09.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Revised: 09/27/2011] [Accepted: 09/28/2011] [Indexed: 10/16/2022]
Abstract
The liver enzyme phenylalanine hydroxylase is responsible for conversion of excess phenylalanine in the diet to tyrosine. Phenylalanine hydroxylase is activated by phenylalanine; this activation is inhibited by the physiological reducing substrate tetrahydrobiopterin. Phosphorylation of Ser16 lowers the concentration of phenylalanine for activation. This review discusses the present understanding of the molecular details of the allosteric regulation of the enzyme.
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Affiliation(s)
- Paul F Fitzpatrick
- Department of Biochemistry and Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, TX 78229-3900, USA.
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20
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Wang S, Lasagna M, Daubner SC, Reinhart GD, Fitzpatrick PF. Fluorescence spectroscopy as a probe of the effect of phosphorylation at serine 40 of tyrosine hydroxylase on the conformation of its regulatory domain. Biochemistry 2011; 50:2364-70. [PMID: 21302933 DOI: 10.1021/bi101844p] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Phosphorylation of Ser40 in the regulatory domain of tyrosine hydroxylase activates the enzyme by increasing the rate constant for dissociation of inhibitory catecholamines from the active site by 3 orders of magnitude. To probe the changes in the structure of the N-terminal domain upon phosphorylation, individual phenylalanine residues at positions 14, 34, and 74 were replaced with tryptophan in a form of the protein in which the endogenous tryptophans had all been mutated to phenylalanine (W(3)F TyrH). The steady-state fluorescence anisotropy of F74W W(3)F TyrH was unaffected by phosphorylation, but the anisotropies of both F14W and F34W W(3)F TyrH increased significantly upon phosphorylation. The fluorescence of the single tryptophan residue at position 74 was less readily quenched by acrylamide than those at the other two positions; fluorescence increased the rate constant for quenching of the residues at positions 14 and 34 but did not affect that for the residue at position 74. Frequency domain analyses were consistent with phosphorylation having no effect on the amplitude of the rotational motion of the indole ring at position 74, resulting in a small increase in the rotational motion of the residue at position 14 and resulting in a larger increase in the rotational motion of the residue at position 34. These results are consistent with the local environment at position 74 being unaffected by phosphorylation, that at position 34 becoming much more flexible upon phosphorylation, and that at position 14 becoming slightly more flexible upon phosphorylation. The results support a model in which phosphorylation at Ser40 at the N-terminus of the regulatory domain causes a conformational change to a more open conformation in which the N-terminus of the protein no longer inhibits dissociation of a bound catecholamine from the active site.
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Affiliation(s)
- Shanzhi Wang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
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21
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Pavon JA, Eser B, Huynh MT, Fitzpatrick PF. Single turnover kinetics of tryptophan hydroxylase: evidence for a new intermediate in the reaction of the aromatic amino acid hydroxylases. Biochemistry 2010; 49:7563-71. [PMID: 20687613 DOI: 10.1021/bi100744r] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Tryptophan hydroxylase (TrpH) uses a non-heme mononuclear iron center to catalyze the tetrahydropterin-dependent hydroxylation of tryptophan to 5-hydroxytryptophan. The reactions of the TrpH.Fe(II), TrpH.Fe(II).tryptophan, TrpH.Fe(II).6MePH(4).tryptophan, and TrpH.Fe(II).6MePH(4).phenylalanine complexes with O(2) were monitored by stopped-flow absorbance spectroscopy and rapid quench methods. The second-order rate constant for the oxidation of TrpH.Fe(II) has a value of 104 M(-1) s(-1) irrespective of the presence of tryptophan. Stopped-flow absorbance analyses of the reaction of the TrpH.Fe(II).6MePH(4).tryptophan complex with oxygen are consistent with the initial step being reversible binding of oxygen, followed by the formation with a rate constant of 65 s(-1) of an intermediate I that has maximal absorbance at 420 nm. The rate constant for decay of I, 4.4 s(-1), matches that for formation of the 4a-hydroxypterin product monitored at 248 nm. Chemical-quench analyses show that 5-hydroxytryptophan forms with a rate constant of 1.3 s(-1) and that overall turnover is limited by a subsequent slow step, presumably product release, with a rate constant of 0.2 s(-1). All of the data with tryptophan as substrate can be described by a five-step mechanism. In contrast, with phenylalanine as substrate, the reaction can be described by three steps: a second-order reaction with oxygen to form I, decay of I as tyrosine forms, and slow product release.
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Affiliation(s)
- Jorge Alex Pavon
- Department of Biochemistry and Biophysics, Texas A&M University, College Station,Texas 77843-2128, USA
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22
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Holowatz LA, Kenney WL. Peripheral mechanisms of thermoregulatory control of skin blood flow in aged humans. J Appl Physiol (1985) 2010; 109:1538-44. [PMID: 20413421 DOI: 10.1152/japplphysiol.00338.2010] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Human skin blood flow is controlled via dual innervation from the sympathetic nervous system. Reflex cutaneous vasoconstriction and vasodilation are both impaired with primary aging, rendering the aged more vulnerable to hypothermia and cardiovascular complications from heat-related illness. Age-related alterations in the thermoregulatory control of skin blood flow occur at multiple points along the efferent arm of the reflex, including 1) diminished sympathetic outflow, 2) altered presynaptic neurotransmitter synthesis, 3) reduced vascular responsiveness, and 4) impairments in downstream (endothelial and vascular smooth muscle) second-messenger signaling. This mechanistic review highlights some of the recent findings in the area of aging and the thermoregulatory control of skin blood flow.
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Affiliation(s)
- Lacy A Holowatz
- Department of Kinesiology, The Pennsylvania State University, Noll Laboratory, University Park, PA 16802, USA.
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23
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Eser BE, Fitzpatrick PF. Measurement of intrinsic rate constants in the tyrosine hydroxylase reaction. Biochemistry 2010; 49:645-52. [PMID: 20025246 DOI: 10.1021/bi901874e] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Tyrosine hydroxylase (TyrH) is a pterin-dependent mononuclear non-heme aromatic amino acid hydroxylase that catalyzes the conversion of tyrosine to dihydroxyphenylalanine (DOPA). Chemical quench analyses of the enzymatic reaction show a burst of DOPA formation, followed by a linear rate equal to the k(cat) value at both 5 and 30 degrees C. The effects of increasing solvent viscosity confirm that k(cat) is approximately 84% limited by diffusion, most probably due to slow product release, and that tyrosine has a commitment to catalysis of 0.45. The effect of viscosity on the k(cat)/K(m) for 6-methyltetrahydropterin is greater than the theoretical limit, consistent with the coupling of pterin binding to the movement of a surface loop. The absorbance changes in the spectrum of the tetrahydropterin during the first turnover, the kinetics of DOPA formation during the first turnover, and the previously described kinetics for formation and decay of the Fe(IV)O intermediate [Eser, B. E., Barr, E. W., Frantom, P. A., Saleh, L., Bollinger, J. M., Jr., Krebs, C., and Fitzpatrick, P. F. (2007) J. Am. Chem. Soc. 129, 11334-11335] were analyzed globally, yielding a single set of rate constants for the TyrH reaction. Reversible binding of oxygen is followed by formation of Fe(IV)O and 4a-hydroxypterin with a rate constant of 13 s(-1) at 5 degrees C. Transfer of oxygen from Fe(IV)O to tyrosine to form DOPA follows with a rate constant of 22 s(-1). Release of DOPA and/or the 4a-hydroxypterin with a rate constant of 0.86 s(-1) completes the turnover.
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Affiliation(s)
- Bekir E Eser
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
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24
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Chow MS, Eser BE, Wilson SA, Hodgson KO, Hedman B, Fitzpatrick PF, Solomon EI. Spectroscopy and kinetics of wild-type and mutant tyrosine hydroxylase: mechanistic insight into O2 activation. J Am Chem Soc 2009; 131:7685-98. [PMID: 19489646 DOI: 10.1021/ja810080c] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Tyrosine hydroxylase (TH) is a pterin-dependent nonheme iron enzyme that catalyzes the hydroxylation of L-tyr to L-DOPA in the rate-limiting step of catecholamine neurotransmitter biosynthesis. We have previously shown that the Fe(II) site in phenylalanine hydroxylase (PAH) converts from six-coordinate (6C) to five-coordinate (5C) only when both substrate + cofactor are bound. However, steady-state kinetics indicate that TH has a different co-substrate binding sequence (pterin + O(2) + L-tyr) than PAH (L-phe + pterin + O(2)). Using X-ray absorption spectroscopy (XAS), and variable-temperature-variable-field magnetic circular dichroism (VTVH MCD) spectroscopy, we have investigated the geometric and electronic structure of the wild-type (WT) TH and two mutants, S395A and E332A, and their interactions with substrates. All three forms of TH undergo 6C --> 5C conversion with tyr + pterin, consistent with the general mechanistic strategy established for O(2)-activating nonheme iron enzymes. We have also applied single-turnover kinetic experiments with spectroscopic data to evaluate the mechanism of the O(2) and pterin reactions in TH. When the Fe(II) site is 6C, the two-electron reduction of O(2) to peroxide by Fe(II) and pterin is favored over individual one-electron reactions, demonstrating that both a 5C Fe(II) and a redox-active pterin are required for coupled O(2) reaction. When the Fe(II) is 5C, the O(2) reaction is accelerated by at least 2 orders of magnitude. Comparison of the kinetics of WT TH, which produces Fe(IV)=O + 4a-OH-pterin, and E332A TH, which does not, shows that the E332 residue plays an important role in directing the protonation of the bridged Fe(II)-OO-pterin intermediate in WT to productively form Fe(IV)=O, which is responsible for hydroxylating L-tyr to L-DOPA.
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Affiliation(s)
- Marina S Chow
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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25
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Wang S, Sura GR, Dangott LJ, Fitzpatrick PF. Identification by hydrogen/deuterium exchange of structural changes in tyrosine hydroxylase associated with regulation. Biochemistry 2009; 48:4972-9. [PMID: 19371093 PMCID: PMC2730116 DOI: 10.1021/bi9004254] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The activity of tyrosine hydroxylase is regulated by reversible phosphorylation of serine residues in an N-terminal regulatory domain and catecholamine inhibition at the active site. Catecholamines such as dopamine bind very tightly to the resting enzyme; phosphorylation of Ser40 decreases the affinity for catecholamines by 3 orders of magnitude. The effects of dopamine binding and phosphorylation of Ser40 on the kinetics of deuterium incorporation into peptide bonds were examined by mass spectrometry. When dopamine is bound, three peptic peptides show significantly slower deuterium incorporation, 35-41 and 42-71 in the regulatory domain and 295-299 in the catalytic domain. In the phosphorylated enzyme, peptide 295-299 shows more rapid incorporation of deuterium, while 35-41 and 42-71 can not be detected. These results are consistent with tyrosine hydroxylase existing in two different conformations. In the closed conformation, the regulatory domain lies across the active site loop containing residues 295-298; this is stabilized when dopamine is bound in the active site. In the open conformation, the regulatory domain has moved out of the active site, allowing substrate access; this conformation is favored by phosphorylation of Ser40.
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Affiliation(s)
- Shanzhi Wang
- Departments of Biochemistry and Biophysics Texas A&M University, College Station TX 77843-2128
| | - Giri R. Sura
- Departments of Biochemistry and Biophysics Texas A&M University, College Station TX 77843-2128
| | - Lawrence J. Dangott
- Protein Chemistry Laboratory Texas A&M University, College Station TX 77843-2128
| | - Paul F. Fitzpatrick
- Departments of Biochemistry and Biophysics Texas A&M University, College Station TX 77843-2128
- Department of Chemistry Texas A&M University, College Station TX 77843-2128
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Otero GA, Pliego-Rivero FB, Porcayo-Mercado R, Mendieta-Alcántara G. Working memory impairment and recovery in iron deficient children. Clin Neurophysiol 2008; 119:1739-1746. [DOI: 10.1016/j.clinph.2008.04.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 03/20/2008] [Accepted: 04/12/2008] [Indexed: 10/21/2022]
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Scholz J, Toska K, Luborzewski A, Maass A, Schünemann V, Haavik J, Moser A. Endogenous tetrahydroisoquinolines associated with Parkinson's disease mimic the feedback inhibition of tyrosine hydroxylase by catecholamines. FEBS J 2008; 275:2109-21. [PMID: 18355318 DOI: 10.1111/j.1742-4658.2008.06365.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
N-methyl-norsalsolinol and related tetrahydroisoquinolines accumulate in the nigrostriatal system of the human brain and are increased in the cerebrospinal fluid of patients with Parkinson's disease. We show here that 6,7-dihydroxylated tetrahydroisoquinolines such as N-methyl-norsalsolinol inhibit tyrosine hydroxylase, the key enzyme in dopamine synthesis, by imitating the mechanisms of catecholamine feedback regulation. Docked into a model of the enzyme's active site, 6,7-dihydroxylated tetrahydroisoquinolines were ligated directly to the iron in the catalytic center, occupying the same position as the catecholamine inhibitor dopamine. In this position, the ligands competed with the essential tetrahydropterin cofactor for access to the active site. Electron paramagnetic resonance spectroscopy revealed that, like dopamine, 6,7-dihydroxylated tetrahydroisoquinolines rapidly convert the catalytic iron to a ferric (inactive) state. Catecholamine binding increases the thermal stability of tyrosine hydroxylase and improves its resistance to proteolysis. We observed a similar effect after incubation with N-methyl-norsalsolinol or norsalsolinol. Following an initial rapid decline in tyrosine hydroxylation, the residual activity remained stable for 5 h at 37 degrees C. Phosphorylation by protein kinase A facilitates the release of bound catecholamines and is the most prominent mechanism of tyrosine hydroxylase reactivation. Protein kinase A also fully restored enzyme activity after incubation with N-methyl-norsalsolinol, demonstrating that tyrosine hydroxylase inhibition by 6,7-dihydroxylated tetrahydroisoquinolines mimics all essential aspects of catecholamine end-product regulation. Increased levels of N-methyl-norsalsolinol and related tetrahydroisoquinolines are therefore likely to accelerate dopamine depletion in Parkinson's disease.
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Affiliation(s)
- Joachim Scholz
- Neurochemistry Research Group, Department of Neurology, University of Lübeck, Germany.
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Eser BE, Barr EW, Frantom PA, Saleh L, Bollinger JM, Krebs C, Fitzpatrick PF. Direct spectroscopic evidence for a high-spin Fe(IV) intermediate in tyrosine hydroxylase. J Am Chem Soc 2007; 129:11334-5. [PMID: 17715926 PMCID: PMC2860260 DOI: 10.1021/ja074446s] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Bekir E Eser
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
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Kaushik P, Gorin F, Vali S. Dynamics of tyrosine hydroxylase mediated regulation of dopamine synthesis. J Comput Neurosci 2007; 22:147-60. [PMID: 17053993 DOI: 10.1007/s10827-006-0004-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Revised: 08/02/2006] [Accepted: 08/02/2006] [Indexed: 02/02/2023]
Abstract
Tyrosine hydroxylase's catalysis of tyrosine to dihydroxyphenylalanine (DOPA) is the highly regulated, rate-limiting step catalyzing the synthesis of the catecholamine neurotransmitter dopamine. Phosphorylation, cofactor-mediated regulation, and the cell's redox status, have been shown to regulate the enzyme's activity. This paper incorporates these regulatory mechanisms into an integrated dynamic model that is capable of demonstrating relative rates of dopamine synthesis under various physiological conditions. Most of the kinetic equations and substrate parameters used in the model correspond with published experimental data, while a few which were not available in literature have been optimized based on explicit assumptions. This kinetic pathway model permits a comparison of the relative regulatory contributions made by variations in substrate, phosphorylation, and redox status on enzymatic activity and permits predictions of potential disease states. For example, the model correctly predicts the recent observation that individuals with haemochromatosis and having excessive iron accumulation are at increased risk for acquiring Parkinsonism, a defect in neuronal dopamine synthesis (Bartzokis et al., 2004; Costello et al., 2004). Alpha synuclein mediated regulation of tyrosine hydroxylase has also been incorporated in the model, allowing an insight into the overexpression and aggregation of alpha synuclein in Parkinson's disease.
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Affiliation(s)
- Poorvi Kaushik
- Cellworks Group Inc., 13962 Pierce Road, Saratoga, CA 95070, USA
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Lim ECH, Seet RCS. Can botulinum toxin put the restless legs syndrome to rest? Med Hypotheses 2007; 69:497-501. [PMID: 17363179 DOI: 10.1016/j.mehy.2007.01.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2007] [Accepted: 01/19/2007] [Indexed: 11/15/2022]
Abstract
The restless legs syndrome (RLS), affecting between 3% and 15% of the population, is characterised by an urge to move the legs during wakefulness, associated with a range of unpleasant sensory symptoms, especially when sitting or lying down at night. The symptoms can even be painful, and lead to sleep disturbances and depression. RLS is treated with dopaminergic agents, anticonvulsants, opioids, clonidine and benzodiazepines. In a small percentage of cases, RLS is refractory to treatment, requiring combination therapy. Botulinum toxin (BTX), derived from the exotoxin of Clostridium botulinum, cleaves soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, causing chemodenervation of cholinergic neurons. BTX has been demonstrated to ameliorate pain syndromes, possibly by reducing peripheral and central sensitization to pain. We postulate that BTX can be injected subcutaneously to the lower limbs to effect amelioration of the symptoms of RLS.
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Affiliation(s)
- Erle C H Lim
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, National University Hospital, Singapore.
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Sura GR, Lasagna M, Gawandi V, Reinhart GD, Fitzpatrick PF. Effects of ligands on the mobility of an active-site loop in tyrosine hydroxylase as monitored by fluorescence anisotropy. Biochemistry 2006; 45:9632-8. [PMID: 16878998 PMCID: PMC2031214 DOI: 10.1021/bi060754b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Fluorescence anisotropy has been used to monitor the effect of ligands on a mobile loop over the active site of tyrosine hydroxylase. Phe184 in the center of the loop was mutated to tryptophan, and the three native tryptophan residues were mutated to phenylalanine to form an enzyme with a single tryptophan residue in the mobile loop. The addition of 6-methyl-5-deazatetrahydropterin to the enzyme resulted in a significant increase in the fluorescence anisotropy. The addition of phenylalanine did not result in a significant change in the anisotropy in the presence or absence of the deazapterin. The K(d) value for the deazapterin was unaffected by the presence of phenylalanine. Qualitatively similar results were obtained with apoenzyme, except that the addition of phenylalanine led to a slight decrease in anisotropy. Frequency-domain lifetime measurements showed that the distribution of lifetimes was unaffected by both the amino acid and deazapterin. Frequency-domain anisotropy analyses were consistent with a decrease in the motion of the sole tryptophan in the presence of the deazapterin. This could be modeled as a decrease in the cone angle for the indole ring of about 12 degrees . The data are consistent with a model in which binding of a tetrahydropterin results in a change in the conformation of the surface loop required for proper formation of the amino acid binding site.
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Affiliation(s)
- Giri R Sura
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128, USA
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Abstract
Brain iron uptake is regulated by the expression of transferrin receptor 1 in endothelial cells of the blood-brain barrier. Transferrin-bound iron in the systemic circulation is endocytosed by brain endothelial cells, and elemental iron is released to brain interstitial fluid, likely by the iron exporter, ferroportin. Transferrin synthesized by oligodendrocytes in the brain binds much of the iron that traverses the blood-brain barrier after oxidation of the iron, most likely by a glycophosphosinositide-linked ceruloplasmin found in astrocytic foot processes that ensheathe brain endothelial cells. Neurons acquire iron from diferric transferrin, but it is less clear how glial cells acquire iron. In aging mammals, iron accumulates in the basal ganglia, and iron accumulation is believed to contribute to neurodegenerative diseases, including Parkinson and Alzheimer disease. Here we consider the possibility that iron accumulations, which are often thought to facilitate free radical generation and oxidative damage, may contain insoluble iron that is unavailable for cellular use, and the pathology associated with iron accumulations may result from functional iron deficiency in some diseases.
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Affiliation(s)
- Tracey A Rouault
- Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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