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Tai MDS, Gamiz-Arco G, Martinez A. Dopamine synthesis and transport: current and novel therapeutics for parkinsonisms. Biochem Soc Trans 2024; 52:1275-1291. [PMID: 38813865 DOI: 10.1042/bst20231061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 05/13/2024] [Accepted: 05/13/2024] [Indexed: 05/31/2024]
Abstract
Parkinsonism is the primary type of movement disorder in adults, encompassing a set of clinical symptoms, including rigidity, tremors, dystonia, bradykinesia, and postural instability. These symptoms are primarily caused by a deficiency in dopamine (DA), an essential neurotransmitter in the brain. Currently, the DA precursor levodopa (synthetic L-DOPA) is the standard medication to treat DA deficiency, but it only addresses symptoms rather than provides a cure. In this review, we provide an overview of disorders associated with DA dysregulation and deficiency, particularly Parkinson's disease and rare inherited disorders leading predominantly to dystonia and/or parkinsonism, even in childhood. Although levodopa is relatively effective for the management of motor dysfunctions, it is less effective for severe forms of parkinsonism and is also associated with side effects and a loss of efficacy over time. We present ongoing efforts to reinforce the effect of levodopa and to develop innovative therapies that target the underlying pathogenic mechanisms affecting DA synthesis and transport, increasing neurotransmission through disease-modifying approaches, such as cell-based therapies, nucleic acid- and protein-based biologics, and small molecules.
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Affiliation(s)
| | - Gloria Gamiz-Arco
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway
| | - Aurora Martinez
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway
- K.G. Jebsen Center for Translational Research in Parkinson's Disease, University of Bergen, 5020 Bergen, Norway
- Neuro-SysMed, Department of Neurology, Haukeland University Hospital, 5021 Bergen, Norway
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2
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Jung-Klawitter S, Richter P, Yuan Y, Welzel K, Kube M, Bähr S, Leibner A, Flory E, Opladen T. Tyrosine hydroxylase variants influence protein expression, cellular localization, stability, enzymatic activity and the physical interaction between tyrosine hydroxylase and GTP cyclohydrolase 1. J Inherit Metab Dis 2024; 47:517-532. [PMID: 38084654 DOI: 10.1002/jimd.12690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 10/17/2023] [Accepted: 11/03/2023] [Indexed: 05/16/2024]
Abstract
Tyrosine hydroxylase (TH) is the rate-limiting enzyme in dopamine biosynthesis catalyzing the tetrahydrobiopterin (BH4)-dependent hydroxylation of tyrosine to L-DOPA. Here, we analyzed 25 TH variants associated with various degrees of dopa-responsive dystonia and evaluate the effect of each variant on protein stability, activity and cellular localization. Furthermore, we investigated the physical interaction between TH and human wildtype (wt) GTP cyclohydrolase 1 (GTPCH) and the effect of variants on this interaction. Our in vitro results classify variants according to their resistance to proteinase K digestion into three groups (stable, intermediate, unstable). Based on their cellular localization, two groups of variants can be identified, variant group one with cytoplasmic distribution and variant group two forming aggregates. These aggregates do not correlate with loss of enzymatic activity but nevertheless might be a good target for molecular chaperones. Unfortunately, no obvious correlation between the half-life of a variant and its enzymatic activity or between solubility, stability and enzymatic activity of a given variant could be found. Excitingly, some variants disrupt the physical interaction between TH and human wildtype GTPCH, thereby interfering with enzymatic activity and offering new druggable targets for therapy. Taken together, our results highlight the importance of an in-depth molecular analysis of each variant in order to be able to classify groups of disease variants and to find specific therapies for each subgroup. Stand-alone in silico analyses predict less precise the effect of specific variants and should be combined with other in vitro analyses in cellular model systems.
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Affiliation(s)
- Sabine Jung-Klawitter
- Medical Faculty, Center for Child and Adolescent Medicine, Pediatric Clinic I, Section of Neuropediatrics and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
| | - Petra Richter
- Medical Faculty, Center for Child and Adolescent Medicine, Pediatric Clinic I, Section of Neuropediatrics and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
| | - Yuheng Yuan
- Medical Faculty, Center for Child and Adolescent Medicine, Pediatric Clinic I, Section of Neuropediatrics and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
| | - Karin Welzel
- Division of Hematology, Cell and Gene Therapy, Paul-Ehrlich-Institute, Langen, Germany
| | - Marie Kube
- Institute of Molecular Biology, Mainz, Germany
| | - Stella Bähr
- Medical Faculty, Center for Child and Adolescent Medicine, Pediatric Clinic I, Section of Neuropediatrics and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
| | - Alexander Leibner
- Medical Faculty, Center for Child and Adolescent Medicine, Pediatric Clinic I, Section of Neuropediatrics and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
| | - Egbert Flory
- Division of Hematology, Cell and Gene Therapy, Paul-Ehrlich-Institute, Langen, Germany
| | - Thomas Opladen
- Medical Faculty, Center for Child and Adolescent Medicine, Pediatric Clinic I, Section of Neuropediatrics and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
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Cronin SJF. New role for GCH1 in cancer. TRANSLATIONAL BREAST CANCER RESEARCH : A JOURNAL FOCUSING ON TRANSLATIONAL RESEARCH IN BREAST CANCER 2024; 5:16. [PMID: 38751681 PMCID: PMC11093062 DOI: 10.21037/tbcr-23-53] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Accepted: 01/24/2024] [Indexed: 05/18/2024]
Affiliation(s)
- Shane J F Cronin
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
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Pardridge WM. Treatment of Parkinson's disease with biologics that penetrate the blood-brain barrier via receptor-mediated transport. Front Aging Neurosci 2023; 15:1276376. [PMID: 38035276 PMCID: PMC10682952 DOI: 10.3389/fnagi.2023.1276376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 10/27/2023] [Indexed: 12/02/2023] Open
Abstract
Parkinson's disease (PD) is characterized by neurodegeneration of nigral-striatal neurons in parallel with the formation of intra-neuronal α-synuclein aggregates, and these processes are exacerbated by neuro-inflammation. All 3 components of PD pathology are potentially treatable with biologics. Neurotrophins, such as glial derived neurotrophic factor or erythropoietin, can promote neural repair. Therapeutic antibodies can lead to disaggregation of α-synuclein neuronal inclusions. Decoy receptors can block the activity of pro-inflammatory cytokines in brain. However, these biologic drugs do not cross the blood-brain barrier (BBB). Biologics can be made transportable through the BBB following the re-engineering of the biologic as an IgG fusion protein, where the IgG domain targets an endogenous receptor-mediated transcytosis (RMT) system within the BBB, such as the insulin receptor or transferrin receptor. The receptor-specific antibody domain of the fusion protein acts as a molecular Trojan horse to ferry the biologic into brain via the BBB RMT pathway. This review describes the re-engineering of all 3 classes of biologics (neurotrophins, decoy receptor, therapeutic antibodies) for BBB delivery and treatment of PD. Targeting the RMT pathway at the BBB also enables non-viral gene therapy of PD using lipid nanoparticles (LNP) encapsulated with plasmid DNA encoding therapeutic genes. The surface of the lipid nanoparticle is conjugated with a receptor-specific IgG that triggers RMT of the LNP across the BBB in vivo.
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Ze LJ, Xu P, Wu JJ, Jin L, Ali Anjum A, Li GQ. Disruption of tetrahydrobiopterin (BH4) biosynthesis pathway affects cuticle pigmentation in Henosepilachna vigintioctopunctata. JOURNAL OF INSECT PHYSIOLOGY 2023; 144:104457. [PMID: 36427533 DOI: 10.1016/j.jinsphys.2022.104457] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 11/18/2022] [Accepted: 11/19/2022] [Indexed: 06/16/2023]
Abstract
Tetrahydrobiopterin (BH4) is produced from guanosine triphosphate (GTP) under catalyzation of GTP cyclohydrolase I (GTPCH), 6-pyruvoyltetrahydropterin synthase (PTPS) and sepiapterin reductase (SR), among others. In Drosophila melanogaster, BH4 and other pteridines are required for cuticle tanning and eye pigmentation. In this study, two Hvgtpch (Hvgtpch-a and Hvgtpch-b), an Hvptps and an Hvsr transcripts were identified in a serious defoliator Henosepilachna vigintioctopunctata. Hvgtpch-a and Hvgtpch-b were highly expressed just before and/or right after the molt, in contrast to Hvptps and Hvsr. RNA interference (RNAi) by injection of a dsgtpch targeting the common fragment of Hvgtpch-a and Hvgtpch-b into the third instar larvae caused albino fourth-instar larvae and pupae. Around 80% of the Hvgtpch RNAi larvae failed to pupate. The remaining 20% of Hvgtpch RNAi pupated beetles did not completely remove the larval/pupal exuviae after emerged as adults and eventually died. Depletion of Hvgtpch at the fourth instar stage resulted in under-pigmented pupae and adults, with significantly low pupation and emergence rates. The Hvgtpch RNAi adults rarely moved and fed on plant leaves; they died within a week after emergence. Silence of Hvptps or Hvsr at the third- and fourth-instar stages led to similar but less serious phenotypes, with lowest influence in the Hvsr RNAi ladybirds. Moreover, RNAi of Hvgtpch, Hvptps or Hvsr did not affect coloration of the larval ocelli and pupal/adult compound eyes. Therefore, our results demonstrated that pteridines are involved in melanin formation but not in eye pigmentation in H. vigintioctopunctata. Moreover, our findings will enable the development of a dsgtpch-based pesticide to control H. vigintioctopunctata larvae.
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Affiliation(s)
- Long-Ji Ze
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests/State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
| | - Ping Xu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests/State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
| | - Jian-Jian Wu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests/State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
| | - Lin Jin
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests/State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
| | - Ahmad Ali Anjum
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests/State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
| | - Guo-Qing Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests/State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
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Rosikon KD, Bone MC, Lawal HO. Regulation and modulation of biogenic amine neurotransmission in Drosophila and Caenorhabditis elegans. Front Physiol 2023; 14:970405. [PMID: 36875033 PMCID: PMC9978017 DOI: 10.3389/fphys.2023.970405] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 01/23/2023] [Indexed: 02/18/2023] Open
Abstract
Neurotransmitters are crucial for the relay of signals between neurons and their target. Monoamine neurotransmitters dopamine (DA), serotonin (5-HT), and histamine are found in both invertebrates and mammals and are known to control key physiological aspects in health and disease. Others, such as octopamine (OA) and tyramine (TA), are abundant in invertebrates. TA is expressed in both Caenorhabditis elegans and Drosophila melanogaster and plays important roles in the regulation of essential life functions in each organism. OA and TA are thought to act as the mammalian homologs of epinephrine and norepinephrine respectively, and when triggered, they act in response to the various stressors in the fight-or-flight response. 5-HT regulates a wide range of behaviors in C. elegans including egg-laying, male mating, locomotion, and pharyngeal pumping. 5-HT acts predominantly through its receptors, of which various classes have been described in both flies and worms. The adult brain of Drosophila is composed of approximately 80 serotonergic neurons, which are involved in modulation of circadian rhythm, feeding, aggression, and long-term memory formation. DA is a major monoamine neurotransmitter that mediates a variety of critical organismal functions and is essential for synaptic transmission in invertebrates as it is in mammals, in which it is also a precursor for the synthesis of adrenaline and noradrenaline. In C. elegans and Drosophila as in mammals, DA receptors play critical roles and are generally grouped into two classes, D1-like and D2-like based on their predicted coupling to downstream G proteins. Drosophila uses histamine as a neurotransmitter in photoreceptors as well as a small number of neurons in the CNS. C. elegans does not use histamine as a neurotransmitter. Here, we review the comprehensive set of known amine neurotransmitters found in invertebrates, and discuss their biological and modulatory functions using the vast literature on both Drosophila and C. elegans. We also suggest the potential interactions between aminergic neurotransmitters systems in the modulation of neurophysiological activity and behavior.
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Affiliation(s)
- Katarzyna D Rosikon
- Neuroscience Program, Department of Biological Sciences, Delaware State University, Dover, DE, United States
| | - Megan C Bone
- Neuroscience Program, Department of Biological Sciences, Delaware State University, Dover, DE, United States
| | - Hakeem O Lawal
- Neuroscience Program, Department of Biological Sciences, Delaware State University, Dover, DE, United States
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Larbalestier H, Keatinge M, Watson L, White E, Gowda S, Wei W, Koler K, Semenova SA, Elkin AM, Rimmer N, Sweeney ST, Mazzolini J, Sieger D, Hide W, McDearmid J, Panula P, MacDonald RB, Bandmann O. GCH1 Deficiency Activates Brain Innate Immune Response and Impairs Tyrosine Hydroxylase Homeostasis. J Neurosci 2022; 42:702-716. [PMID: 34876467 PMCID: PMC8805627 DOI: 10.1523/jneurosci.0653-21.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 10/08/2021] [Accepted: 11/03/2021] [Indexed: 11/21/2022] Open
Abstract
The Parkinson's disease (PD) risk gene GTP cyclohydrolase 1 (GCH1) catalyzes the rate-limiting step in tetrahydrobiopterin (BH4) synthesis, an essential cofactor in the synthesis of monoaminergic neurotransmitters. To investigate the mechanisms by which GCH1 deficiency may contribute to PD, we generated a loss of function zebrafish gch1 mutant (gch1-/-), using CRISPR/Cas technology. gch1-/- zebrafish develop marked monoaminergic neurotransmitter deficiencies by 5 d postfertilization (dpf), movement deficits by 8 dpf and lethality by 12 dpf. Tyrosine hydroxylase (Th) protein levels were markedly reduced without loss of ascending dopaminergic (DAergic) neurons. L-DOPA treatment of gch1-/- larvae improved survival without ameliorating the motor phenotype. RNAseq of gch1-/- larval brain tissue identified highly upregulated transcripts involved in innate immune response. Subsequent experiments provided morphologic and functional evidence of microglial activation in gch1-/- The results of our study suggest that GCH1 deficiency may unmask early, subclinical parkinsonism and only indirectly contribute to neuronal cell death via immune-mediated mechanisms. Our work highlights the importance of functional validation for genome-wide association studies (GWAS) risk factors and further emphasizes the important role of inflammation in the pathogenesis of PD.SIGNIFICANCE STATEMENT Genome-wide association studies have now identified at least 90 genetic risk factors for sporadic Parkinson's disease (PD). Zebrafish are an ideal tool to determine the mechanistic role of genome-wide association studies (GWAS) risk genes in a vertebrate animal model. The discovery of GTP cyclohydrolase 1 (GCH1) as a genetic risk factor for PD was counterintuitive, GCH1 is the rate-limiting enzyme in the synthesis of dopamine (DA), mutations had previously been described in the non-neurodegenerative movement disorder dopa-responsive dystonia (DRD). Rather than causing DAergic cell death (as previously hypothesized by others), we now demonstrate that GCH1 impairs tyrosine hydroxylase (Th) homeostasis and activates innate immune mechanisms in the brain and provide evidence of microglial activation and phagocytic activity.
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Affiliation(s)
- Hannah Larbalestier
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, United Kingdom
- Bateson Centre, Firth Court, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Marcus Keatinge
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, United Kingdom
- Bateson Centre, Firth Court, University of Sheffield, Sheffield S10 2TN, United Kingdom
- Centre for Discovery Brain Sciences, Chancellor's Building, The University of Edinburgh, Edinburgh EH16 4SB, United Kingdom
| | - Lisa Watson
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, United Kingdom
- Bateson Centre, Firth Court, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Emma White
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, United Kingdom
- Bateson Centre, Firth Court, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Siri Gowda
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, United Kingdom
- Bateson Centre, Firth Court, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Wenbin Wei
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, United Kingdom
| | - Katjusa Koler
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, United Kingdom
| | - Svetlana A Semenova
- Department of Anatomy, University of Helsinki, Helsinki, Finland, 00014
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland 20892
| | - Adam M Elkin
- Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Neal Rimmer
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester LE1 7RH, United Kingdom
| | - Sean T Sweeney
- Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Julie Mazzolini
- Centre for Discovery Brain Sciences, Chancellor's Building, The University of Edinburgh, Edinburgh EH16 4SB, United Kingdom
| | - Dirk Sieger
- Centre for Discovery Brain Sciences, Chancellor's Building, The University of Edinburgh, Edinburgh EH16 4SB, United Kingdom
| | - Winston Hide
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, United Kingdom
- Department of Pathology, Beth Israel Medical Center, Boston, Massachusetts 02215
- Harvard Medical School, Boston, Massachusetts 02115
| | - Jonathan McDearmid
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester LE1 7RH, United Kingdom
| | - Pertti Panula
- Department of Anatomy, University of Helsinki, Helsinki, Finland, 00014
| | - Ryan B MacDonald
- Bateson Centre, Firth Court, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Oliver Bandmann
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, United Kingdom
- Bateson Centre, Firth Court, University of Sheffield, Sheffield S10 2TN, United Kingdom
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Kleppe R, Waheed Q, Ruoff P. DOPA Homeostasis by Dopamine: A Control-Theoretic View. Int J Mol Sci 2021; 22:12862. [PMID: 34884667 PMCID: PMC8657751 DOI: 10.3390/ijms222312862] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/23/2021] [Accepted: 11/23/2021] [Indexed: 12/24/2022] Open
Abstract
Dopamine (DA) is an important signal mediator in the brain as well as in the periphery. The term "dopamine homeostasis" occasionally found in the literature refers to the fact that abnormal DA levels can be associated with a variety of neuropsychiatric disorders. An analysis of the negative feedback inhibition of tyrosine hydroxylase (TH) by DA indicates, with support from the experimental data, that the TH-DA negative feedback loop has developed to exhibit 3,4-dihydroxyphenylalanine (DOPA) homeostasis by using DA as a derepression regulator. DA levels generally decline when DOPA is removed, for example, by increased oxidative stress. Robust DOPA regulation by DA further implies that maximum vesicular DA levels are established, which appear necessary for a reliable translation of neural activity into a corresponding chemical transmitter signal. An uncontrolled continuous rise (windup) in DA occurs when Levodopa treatment exceeds a critical dose. Increased oxidative stress leads to the successive breakdown of DOPA homeostasis and to a corresponding reduction in DA levels. To keep DOPA regulation robust, the vesicular DA loading requires close to zero-order kinetics combined with a sufficiently high compensatory flux provided by TH. The protection of DOPA and DA due to a channeling complex is discussed.
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Affiliation(s)
- Rune Kleppe
- Norwegian Center for Maritime and Diving Medicine, Haukeland University Hospital, 5021 Bergen, Norway;
| | - Qaiser Waheed
- Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, 4021 Stavanger, Norway;
| | - Peter Ruoff
- Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, 4021 Stavanger, Norway;
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Personalized Medicine to Improve Treatment of Dopa-Responsive Dystonia-A Focus on Tyrosine Hydroxylase Deficiency. J Pers Med 2021; 11:jpm11111186. [PMID: 34834538 PMCID: PMC8625014 DOI: 10.3390/jpm11111186] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 11/25/2022] Open
Abstract
Dopa-responsive dystonia (DRD) is a rare movement disorder associated with defective dopamine synthesis. This impairment may be due to the fact of a deficiency in GTP cyclohydrolase I (GTPCHI, GCH1 gene), sepiapterin reductase (SR), tyrosine hydroxylase (TH), or 6-pyruvoyl tetrahydrobiopterin synthase (PTPS) enzyme functions. Mutations in GCH1 are most frequent, whereas fewer cases have been reported for individual SR-, PTP synthase-, and TH deficiencies. Although termed DRD, a subset of patients responds poorly to L-DOPA. As this is regularly observed in severe cases of TH deficiency (THD), there is an urgent demand for more adequate or personalized treatment options. TH is a key enzyme that catalyzes the rate-limiting step in catecholamine biosynthesis, and THD patients often present with complex and variable phenotypes, which results in frequent misdiagnosis and lack of appropriate treatment. In this expert opinion review, we focus on THD pathophysiology and ongoing efforts to develop novel therapeutics for this rare disorder. We also describe how different modeling approaches can be used to improve genotype to phenotype predictions and to develop in silico testing of treatment strategies. We further discuss the current status of mathematical modeling of catecholamine synthesis and how such models can be used together with biochemical data to improve treatment of DRD patients.
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Khairallah A, Ross CJ, Tastan Bishop Ö. GTP Cyclohydrolase I as a Potential Drug Target: New Insights into Its Allosteric Modulation via Normal Mode Analysis. J Chem Inf Model 2021; 61:4701-4719. [PMID: 34450011 DOI: 10.1021/acs.jcim.1c00898] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Guanosine triphosphate (GTP) cyclohydrolase I (GCH1) catalyzes the conversion of GTP into dihydroneopterin triphosphate (DHNP). DHNP is the first intermediate of the folate de novo biosynthesis pathway in prokaryotic and lower eukaryotic microorganisms and the tetrahydrobiopterin (BH4) biosynthesis pathway in higher eukaryotes. The de novo folate biosynthesis provides essential cofactors for DNA replication, cell division, and synthesis of key amino acids in rapidly replicating pathogen cells, such as Plasmodium falciparum (P. falciparum), a causative agent of malaria. In eukaryotes, the product of the BH4 biosynthesis pathway is essential for the production of nitric oxide and several neurotransmitter precursors. An increased copy number of the malaria parasite P. falciparum GCH1 gene has been reported to influence antimalarial antifolate drug resistance evolution, whereas mutations in the human GCH1 are associated with neuropathic and inflammatory pain disorders. Thus, GCH1 stands as an important and attractive drug target for developing therapeutics. The GCH1 intrinsic dynamics that modulate its activity remains unclear, and key sites that exert allosteric effects across the structure are yet to be elucidated. This study employed the anisotropic network model to analyze the intrinsic motions of the GCH1 structure alone and in complex with its regulatory partner protein. We showed that the GCH1 tunnel-gating mechanism is regulated by a global shear motion and an outward expansion of the central five-helix bundle. We further identified hotspot residues within sites of structural significance for the GCH1 intrinsic allosteric modulation. The obtained results can provide a solid starting point to design novel antineuropathic treatments for humans and novel antimalarial drugs against the malaria parasite P. falciparum GCH1 enzyme.
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Affiliation(s)
- Afrah Khairallah
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown 6140, South Africa
| | - Caroline J Ross
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown 6140, South Africa
| | - Özlem Tastan Bishop
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown 6140, South Africa
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Dalvi-Garcia F, Fonseca LL, Vasconcelos ATR, Hedin-Pereira C, Voit EO. A model of dopamine and serotonin-kynurenine metabolism in cortisolemia: Implications for depression. PLoS Comput Biol 2021; 17:e1008956. [PMID: 33970902 PMCID: PMC8136856 DOI: 10.1371/journal.pcbi.1008956] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 05/20/2021] [Accepted: 04/10/2021] [Indexed: 12/31/2022] Open
Abstract
A major factor contributing to the etiology of depression is a neurochemical imbalance of the dopaminergic and serotonergic systems, which is caused by persistently high levels of circulating stress hormones. Here, a computational model is proposed to investigate the interplay between dopaminergic and serotonergic-kynurenine metabolism under cortisolemia and its consequences for the onset of depression. The model was formulated as a set of nonlinear ordinary differential equations represented with power-law functions. Parameter values were obtained from experimental data reported in the literature, biological databases, and other general information, and subsequently fine-tuned through optimization. Model simulations predict that changes in the kynurenine pathway, caused by elevated levels of cortisol, can increase the risk of neurotoxicity and lead to increased levels of 3,4-dihydroxyphenylaceltahyde (DOPAL) and 5-hydroxyindoleacetaldehyde (5-HIAL). These aldehydes contribute to alpha-synuclein aggregation and may cause mitochondrial fragmentation. Further model analysis demonstrated that the inhibition of both serotonin transport and kynurenine-3-monooxygenase decreased the levels of DOPAL and 5-HIAL and the neurotoxic risk often associated with depression. The mathematical model was also able to predict a novel role of the dopamine and serotonin metabolites DOPAL and 5-HIAL in the ethiology of depression, which is facilitated through increased cortisol levels. Finally, the model analysis suggests treatment with a combination of inhibitors of serotonin transport and kynurenine-3-monooxygenase as a potentially effective pharmacological strategy to revert the slow-down in monoamine neurotransmission that is often triggered by inflammation.
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Affiliation(s)
- Felipe Dalvi-Garcia
- Bioinformatics Lab, National Laboratory for Scientific Computing, Petrópolis, Rio de Janeiro, Brazil
- School of Medicine and Surgery, Federal University of the State of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luis L. Fonseca
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Ana Tereza R. Vasconcelos
- Bioinformatics Lab, National Laboratory for Scientific Computing, Petrópolis, Rio de Janeiro, Brazil
| | - Cecilia Hedin-Pereira
- Center of Health Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
- Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Eberhard O. Voit
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
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12
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Varghaei P, Yoon G, Estiar MA, Veyron S, Leveille E, Dupré N, Trempe JF, Rouleau GA, Gan-Or Z. GCH1 mutations in hereditary spastic paraplegia. Clin Genet 2021; 100:51-58. [PMID: 33713342 DOI: 10.1111/cge.13955] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 03/02/2021] [Accepted: 03/05/2021] [Indexed: 01/09/2023]
Abstract
GCH1 mutations have been associated with dopa-responsive dystonia (DRD), Parkinson's disease (PD) and tetrahydrobiopterin (BH4 )-deficient hyperphenylalaninemia B. Recently, GCH1 mutations have been reported in five patients with hereditary spastic paraplegia (HSP). Here, we analyzed a total of 400 HSP patients (291 families) from different centers across Canada by whole exome sequencing (WES). Three patients with heterozygous GCH1 variants were identified: monozygotic twins with a p.(Ser77_Leu82del) variant, and a patient with a p.(Val205Glu) variant. The former variant is predicted to be likely pathogenic and the latter is pathogenic. The three patients presented with childhood-onset lower limb spasticity, hyperreflexia and abnormal plantar responses. One of the patients had diurnal fluctuations, and none had parkinsonism or dystonia. Phenotypic differences between the monozygotic twins were observed, who responded well to levodopa treatment. Pathway enrichment analysis suggested that GCH1 shares processes and pathways with other HSP-associated genes, and structural analysis of the variants indicated a disruptive effect. In conclusion, GCH1 mutations may cause HSP; therefore, we suggest a levodopa trial in HSP patients and including GCH1 in the screening panels of HSP genes. Clinical differences between monozygotic twins suggest that environmental factors, epigenetics, and stochasticity could play a role in the clinical presentation.
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Affiliation(s)
- Parizad Varghaei
- Division of Experimental Medicine, Department of Medicine, McGill University, Montreal, Quebec, Canada.,Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Grace Yoon
- Divisions of Neurology and Clinical and Metabolic Genetics, Department of Pediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Canada
| | - Mehrdad A Estiar
- Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.,Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Simon Veyron
- Department of Pharmacology & Therapeutics and Centre de Recherche en Biologie Structurale - FRQS, McGill University, Montréal, Canada
| | - Etienne Leveille
- Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Nicolas Dupré
- Axe Neurosciences, CHU de Québec-Université Laval, Quebec City, Québec, Canada.,Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, Quebec, Canada
| | - Jean-François Trempe
- Department of Pharmacology & Therapeutics and Centre de Recherche en Biologie Structurale - FRQS, McGill University, Montréal, Canada
| | - Guy A Rouleau
- Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.,Department of Human Genetics, McGill University, Montreal, Quebec, Canada.,Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Ziv Gan-Or
- Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.,Department of Human Genetics, McGill University, Montreal, Quebec, Canada.,Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
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13
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Velvet Antler Methanol Extracts Ameliorate Parkinson's Disease by Inhibiting Oxidative Stress and Neuroinflammation: From C. elegans to Mice. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:8864395. [PMID: 33505591 PMCID: PMC7811427 DOI: 10.1155/2021/8864395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 11/15/2020] [Accepted: 12/03/2020] [Indexed: 01/03/2023]
Abstract
Velvet antler is the traditional tonic food or medicine used in East Asia for treating aging-related diseases. Herein, we try to dissect the pharmacology of methanol extracts (MEs) of velvet antler on Parkinson's disease (PD). Caenorhabditis elegans studies showed that MEs decreased the aggregation of α-synuclein and protected oxidative stress-induced DAergic neuron degeneration. In vitro cellular data indicated that MEs suppressed the LPS-induced MAPKs and NF-κB activation, therefore inhibiting overproduction of reactive oxygen species, nitric oxide, tumor necrosis factor-α, and interleukin-6; blocking microglia activation; and protecting DAergic neurons from the microglia-mediated neurotoxicity. In vivo MPTP-induced PD mouse investigations found that MEs prevented MPTP-induced neuron loss in the substantia nigra and improved the behavioral rotating rod performance in MPTP-treated mice by increasing the expression level of tyrosine hydroxylase (TH) and downregulating α-synuclein protein expression. In all, these results demonstrate that MEs ameliorate PD by inhibiting oxidative stress and neuroinflammation.
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14
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Dunkley PR, Dickson PW. Tyrosine hydroxylase phosphorylation
in vivo. J Neurochem 2019; 149:706-728. [DOI: 10.1111/jnc.14675] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 01/23/2019] [Accepted: 01/29/2019] [Indexed: 12/31/2022]
Affiliation(s)
- Peter R. Dunkley
- The School of Biomedical Sciences and Pharmacy and The Hunter Medical Research Institute The University of Newcastle University Drive Callaghan NSW Australia
| | - Phillip W. Dickson
- The School of Biomedical Sciences and Pharmacy and The Hunter Medical Research Institute The University of Newcastle University Drive Callaghan NSW Australia
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15
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Lu L, Jia H, Gao G, Duan C, Ren J, Li Y, Yang H. Pink1 Regulates Tyrosine Hydroxylase Expression and Dopamine Synthesis. J Alzheimers Dis 2018; 63:1361-1371. [DOI: 10.3233/jad-170832] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Lingling Lu
- Department of Neurobiology, Capital Medical University, Center of Parkinson’s Disease, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Beijing, China
| | - Huanzhen Jia
- Department of Neurobiology, Capital Medical University, Center of Parkinson’s Disease, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Beijing, China
| | - Ge Gao
- Department of Neurobiology, Capital Medical University, Center of Parkinson’s Disease, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Beijing, China
| | - Chunli Duan
- Department of Neurobiology, Capital Medical University, Center of Parkinson’s Disease, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Beijing, China
| | - Jing Ren
- Department of Neurobiology, Capital Medical University, Center of Parkinson’s Disease, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Beijing, China
| | - Yi Li
- Department of Neurobiology, Capital Medical University, Center of Parkinson’s Disease, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Beijing, China
| | - Hui Yang
- Department of Neurobiology, Capital Medical University, Center of Parkinson’s Disease, Beijing Institute for Brain Disorders, Beijing Center of Neural Regeneration and Repair, Key Laboratory for Neurodegenerative Diseases of the Ministry of Education, Beijing, China
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16
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Sulzer D, Cragg SJ, Rice ME. Striatal dopamine neurotransmission: regulation of release and uptake. ACTA ACUST UNITED AC 2016; 6:123-148. [PMID: 27141430 DOI: 10.1016/j.baga.2016.02.001] [Citation(s) in RCA: 236] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Dopamine (DA) transmission is governed by processes that regulate release from axonal boutons in the forebrain and the somatodendritic compartment in midbrain, and by clearance by the DA transporter, diffusion, and extracellular metabolism. We review how axonal DA release is regulated by neuronal activity and by autoreceptors and heteroreceptors, and address how quantal release events are regulated in size and frequency. In brain regions densely innervated by DA axons, DA clearance is due predominantly to uptake by the DA transporter, whereas in cortex, midbrain, and other regions with relatively sparse DA inputs, the norepinephrine transporter and diffusion are involved. We discuss the role of DA uptake in restricting the sphere of influence of DA and in temporal accumulation of extracellular DA levels upon successive action potentials. The tonic discharge activity of DA neurons may be translated into a tonic extracellular DA level, whereas their bursting activity can generate discrete extracellular DA transients.
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Affiliation(s)
- David Sulzer
- Depts of Psychiatry, Neurology, & Pharmacology, NY State Psychiatric Institute, Columbia University, New York, NY, USA
| | - Stephanie J Cragg
- Dept Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Margaret E Rice
- Depts of Neurosurgery & Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA
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17
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Stewart HJ, Ralph GS, Fong-Wong L, Strickland I, McCloskey L, Barnes L, Blount I, Wells O, Truran CJM, Kingsman AJ, Palfi S, Mitrophanous KA. Optimizing Transgene Configuration and Protein Fusions to Maximize Dopamine Production for the Gene Therapy of Parkinson's Disease. HUM GENE THER CL DEV 2016; 27:100-10. [PMID: 27470285 DOI: 10.1089/humc.2016.056] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Pharmacological dopamine replacement therapies provide the most well-established treatments for Parkinson's disease (PD). However, these long-term treatments can lead to motor complications and off-target effects. ProSavin(®), a lentiviral vector (LV)-based gene therapy approach aimed at restoring local and continuous dopamine production, through delivery of three enzymes in the dopamine biosynthesis pathway, was demonstrated to be safe and well-tolerated in a phase I/II clinical study of patients with advanced PD. Although improvements in motor behaviour were observed, the data indicated that higher levels of dopamine replacement might be required to maximize benefit. We attempted to increase production of dopamine, and its precursor L-Dopa in LV-transduced cells, by optimizing the gene order in the ProSavin expression cassette, and by creating fusions of two or three of the transgenes, using linker sequences. In vitro analysis showed that several gene arrangements provided significantly increased dopamine and/or L-Dopa production compared with ProSavin, and that LV titers and transgene expression were not affected by introducing gene fusions. One vector, equine infectious anemia virus (EIAV)-TCiA, was selected for further characterization and showed significant improvements in dopamine and L-Dopa production compared with ProSavin, in human neuronal cells. Further characterization of EIAV-TCiA demonstrated expression of all three dopamine enzymes in vivo and faithful delivery and integration of the expected gene expression cassette within the genome of target cells, as assessed by Northern and Southern blotting. In conclusion, we have developed a novel LV vector with an increased capacity for L-Dopa and dopamine production compared with the current ProSavin vector. Clinical evaluation of this vector will be performed to assess the benefits in patients with PD.
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Affiliation(s)
| | - G Scott Ralph
- 1 Oxford BioMedica (UK) Ltd. , Oxford, United Kingdom
| | - Liang Fong-Wong
- 2 Henry Wellcome L.I.N.E., University of Bristol , Bristol BS1 3NY, United Kingdom
| | - Iain Strickland
- 2 Henry Wellcome L.I.N.E., University of Bristol , Bristol BS1 3NY, United Kingdom
| | | | - Lucy Barnes
- 1 Oxford BioMedica (UK) Ltd. , Oxford, United Kingdom
| | - Ian Blount
- 1 Oxford BioMedica (UK) Ltd. , Oxford, United Kingdom
| | - Owen Wells
- 1 Oxford BioMedica (UK) Ltd. , Oxford, United Kingdom
| | | | | | - Stéphane Palfi
- 3 AP-HP, Groupe Hospitalier Henri-Mondor, DHU PePsy, Neurochirurgie, INSERM IMRB U955 eq.14, Université Paris Est Créteil (UPEC) , Faculté de Médecine, Creteil, F-94010, France
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18
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Parra LA, Baust TB, Smith AD, Jaumotte JD, Zigmond MJ, Torres S, Leak RK, Pino JA, Torres GE. The Molecular Chaperone Hsc70 Interacts with Tyrosine Hydroxylase to Regulate Enzyme Activity and Synaptic Vesicle Localization. J Biol Chem 2016; 291:17510-22. [PMID: 27365397 DOI: 10.1074/jbc.m116.728782] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Indexed: 12/25/2022] Open
Abstract
We previously reported that the vesicular monoamine transporter 2 (VMAT2) is physically and functionally coupled with Hsc70 as well as with the dopamine synthesis enzymes tyrosine hydroxylase (TH) and aromatic amino acid decarboxylase, providing a novel mechanism for dopamine homeostasis regulation. Here we expand those findings to demonstrate that Hsc70 physically and functionally interacts with TH to regulate the enzyme activity and synaptic vesicle targeting. Co-immunoprecipitation assays performed in brain tissue and heterologous cells demonstrated that Hsc70 interacts with TH and aromatic amino acid decarboxylase. Furthermore, in vitro binding assays showed that TH directly binds the substrate binding and carboxyl-terminal domains of Hsc70. Immunocytochemical studies indicated that Hsc70 and TH co-localize in midbrain dopaminergic neurons. The functional significance of the Hsc70-TH interaction was then investigated using TH activity assays. In both dopaminergic MN9D cells and mouse brain synaptic vesicles, purified Hsc70 facilitated an increase in TH activity. Neither the closely related protein Hsp70 nor the unrelated Hsp60 altered TH activity, confirming the specificity of the Hsc70 effect. Overexpression of Hsc70 in dopaminergic MN9D cells consistently resulted in increased TH activity whereas knockdown of Hsc70 by short hairpin RNA resulted in decreased TH activity and dopamine levels. Finally, in cells with reduced levels of Hsc70, the amount of TH associated with synaptic vesicles was decreased. This effect was rescued by addition of purified Hsc70. Together, these data demonstrate a novel interaction between Hsc70 and TH that regulates the activity and localization of the enzyme to synaptic vesicles, suggesting an important role for Hsc70 in dopamine homeostasis.
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Affiliation(s)
| | | | - Amanda D Smith
- Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
| | - Juliann D Jaumotte
- Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
| | - Michael J Zigmond
- Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
| | - Soledad Torres
- the Centro de Investigación y Modelamiento de Fenómenos Aleatorios Valparaíso, Faculty of Engineering, Universidad de Valparaíso, 2362905 Valparaíso, Chile
| | - Rehana K Leak
- the Division of Pharmaceutical Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282, and
| | - Jose A Pino
- the Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Gonzalo E Torres
- the Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, Florida 32610
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19
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Chen P, Wang J, Li H, Li Y, Chen P, Li T, Chen X, Xiao J, Zhang L. Role of GTP-CHI links PAH and TH in melanin synthesis in silkworm, Bombyx mori. Gene 2015; 567:138-45. [PMID: 25958343 DOI: 10.1016/j.gene.2015.03.043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 03/19/2015] [Accepted: 03/20/2015] [Indexed: 10/23/2022]
Abstract
In insects, pigment patterns are formed by melanin, ommochromes, and pteridines. Here, the effects of pteridine synthesis on melanin formation were studied using 4th instar larvae of a wild-type silkworm strain, dazao (Bombyx mori), with normal color and markings. Results from injected larvae and in vitro integument culture indicated that decreased activity of guanosine triphosphate cyclohydrolase I (GTP-CH I, a rate-limiting enzyme for pteridine synthesis), lowers BH4 (6R-l-erythro-5,6,7,8-tetrahydrobiopterin, a production correlated with GTP-CH I activity) levels and eliminates markings and coloration. The conversion of phenylalanine and tyrosine to melanin was prevented when GTP-CH I was inhibited. When BH4 was added, phenylalanine was converted to tyrosine, and the tyrosine concentration increased. Tyrosine was then converted to melanin to create normal markings and coloration. Decreasing GTP-CH I activity did not affect L-DOPA (3,4-l-dihydroxyphenylalanine). GTP-CH I affected melanin synthesis by generating the BH4 used in two key reaction steps: (1) conversion of phenylalanine to tyrosine by PAH (phenylalanine hydroxylase) and (2) conversion of tyrosine to L-DOPA by TH (tyrosine hydroxylase). Expression profiles of BmGTPCH Ia, BmGTPCH Ib, BmTH, and BmPAH in the integument were consistent with the current findings.
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Affiliation(s)
- Ping Chen
- College of Biotechnology, Southwest University, Chongqing 400716, China.
| | - Jiying Wang
- College of Biotechnology, Southwest University, Chongqing 400716, China
| | - Haiyin Li
- College of Biotechnology, Southwest University, Chongqing 400716, China
| | - Yan Li
- College of Biotechnology, Southwest University, Chongqing 400716, China
| | - Peng Chen
- College of Biotechnology, Southwest University, Chongqing 400716, China
| | - Tian Li
- College of Biotechnology, Southwest University, Chongqing 400716, China
| | - Xi Chen
- College of Biotechnology, Southwest University, Chongqing 400716, China
| | - Junjie Xiao
- College of Biotechnology, Southwest University, Chongqing 400716, China
| | - Liang Zhang
- College of Biotechnology, Southwest University, Chongqing 400716, China
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20
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Neuroprotective effects of 5-(4-hydroxy-3-dimethoxybenzylidene)-thiazolidinone in MPTP induced Parkinsonism model in mice. Neuropharmacology 2015; 93:209-18. [PMID: 25680233 DOI: 10.1016/j.neuropharm.2015.01.030] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 01/19/2015] [Accepted: 01/26/2015] [Indexed: 01/08/2023]
Abstract
Parkinson's disease (PD) is a neurological disorder characterized by degeneration of nigrostriatal dopaminergic (DAergic) system. Present treatment targeting to DAergic system solely ameliorated the symptoms but failed to retard the DAergic neuron degeneration, therefore new therapeutic methods aiming at preventing or delaying the neurodegenerative process are urgently needed. In the present study, we found that 5-(4-hydroxy-3-dimethoxybenzylidene)-2-thioxo-4-thiazolidinone (RD-1), a compound derived from rhodanine, protected DAergicneurons from neurotoxicity of MPTP/MPP(+). Firstly, RD-1 significantly improved the locomotor ability in the MPTP mice model, and elevated the tyrosine hydroxylase (TH) positive cell numbers in substantianigra pars compacta (SNpc) and the integrated optical density (IOD) of TH-positive nerve fibers in striatum respectively. Since mitochondrial dysfunction plays an important role in pathogenesis of PD, thereby we investigated the molecular mechanisms of RD-1 against MPTP/MPP(+) neurotoxicity, focusing on its effects on the mitochondrial dysfunction. Immunoblotting analysis showed that RD-1 significantly elevated the Parkin and Miro2 expression levels in acute MPTP treated mice, and improved mitochondrial membrane potential and ATP synthesis in MPP(+)-treated Neuro-2a cells. Moreover, RD-1attenuated impaired mitochondrial transport and vesicle release dysfunction evoked by MPP(+) cytotoxicity in cultured primary mesencephalic neurons. Taken together, these results indicate that improving the mitochondrial dysfunction may be a good choice to delay the neurodegenerative progression commonly associated with PD.
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21
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RETRACTED ARTICLE: Association of Catechol-O-methyltransferase val/met polymorphism with cognitive function in Gilles de la Tourette syndrome patients. Neurol Sci 2014; 36:561-70. [DOI: 10.1007/s10072-014-1992-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 10/27/2014] [Indexed: 10/24/2022]
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22
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Complex molecular regulation of tyrosine hydroxylase. J Neural Transm (Vienna) 2014; 121:1451-81. [PMID: 24866693 DOI: 10.1007/s00702-014-1238-7] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 05/04/2014] [Indexed: 12/16/2022]
Abstract
Tyrosine hydroxylase, the rate-limiting enzyme in catecholamine biosynthesis, is strictly controlled by several interrelated regulatory mechanisms. Enzyme synthesis is controlled by epigenetic factors, transcription factors, and mRNA levels. Enzyme activity is regulated by end-product feedback inhibition. Phosphorylation of the enzyme is catalyzed by several protein kinases and dephosphorylation is mediated by two protein phosphatases that establish a sensitive process for regulating enzyme activity on a minute-to-minute basis. Interactions between tyrosine hydroxylase and other proteins introduce additional layers to the already tightly controlled production of catecholamines. Tyrosine hydroxylase degradation by the ubiquitin-proteasome coupled pathway represents yet another mechanism of regulation. Here, we revisit the myriad mechanisms that regulate tyrosine hydroxylase expression and activity and highlight their physiological importance in the control of catecholamine biosynthesis.
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23
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Ata B, Tulandi T. Pathophysiology of ovarian hyperstimulation syndrome and strategies for its prevention and treatment. ACTA ACUST UNITED AC 2014. [DOI: 10.1586/eog.09.10] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Meiser J, Weindl D, Hiller K. Complexity of dopamine metabolism. Cell Commun Signal 2013; 11:34. [PMID: 23683503 PMCID: PMC3693914 DOI: 10.1186/1478-811x-11-34] [Citation(s) in RCA: 414] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 05/10/2013] [Indexed: 01/15/2023] Open
Abstract
: Parkinson's disease (PD) coincides with a dramatic loss of dopaminergic neurons within the substantia nigra. A key player in the loss of dopaminergic neurons is oxidative stress. Dopamine (DA) metabolism itself is strongly linked to oxidative stress as its degradation generates reactive oxygen species (ROS) and DA oxidation can lead to endogenous neurotoxins whereas some DA derivatives show antioxidative effects. Therefore, DA metabolism is of special importance for neuronal redox-homeostasis and viability.In this review we highlight different aspects of dopamine metabolism in the context of PD and neurodegeneration. Since most reviews focus only on single aspects of the DA system, we will give a broader overview by looking at DA biosynthesis, sequestration, degradation and oxidation chemistry at the metabolic level, as well as at the transcriptional, translational and posttranslational regulation of all enzymes involved. This is followed by a short overview of cellular models currently used in PD research. Finally, we will address the topic from a medical point of view which directly aims to encounter PD.
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Affiliation(s)
- Johannes Meiser
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 7, avenue des Hauts-Fourneaux, L-4362 Esch-Belval, Luxembourg
| | - Daniel Weindl
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 7, avenue des Hauts-Fourneaux, L-4362 Esch-Belval, Luxembourg
| | - Karsten Hiller
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 7, avenue des Hauts-Fourneaux, L-4362 Esch-Belval, Luxembourg
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25
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Bisaglia M, Greggio E, Beltramini M, Bubacco L. Dysfunction of dopamine homeostasis: clues in the hunt for novel Parkinson's disease therapies. FASEB J 2013; 27:2101-10. [PMID: 23463698 DOI: 10.1096/fj.12-226852] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Parkinson's disease is the second most common neurodegenerative disorder and, at present, has no cure. Both environmental and genetic factors have been implicated in the etiology of the disease; however, the pathogenic pathways leading to neuronal degeneration are still unclear. Parkinson's disease is characterized by the preferential death of a subset of neurons in the mesencephalon that use dopamine as neurotransmitter for synaptic communication. Dopamine is a highly reactive molecule that can lead to cytotoxicity if not properly stored and metabolized. Targeting any of the pathways that tightly control this neurotransmitter holds great therapeutic expectations. In this article we present a comprehensive overview of the cellular pathways that control dopamine fate and discuss potential therapeutic approaches to counteract or slow Parkinson's disease onset and progression.
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Affiliation(s)
- Marco Bisaglia
- Molecular Physiology and Biophysics Unit, Department of Biology, University of Padova, Padua, Italy.
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26
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Caldwell KA, Shu Y, Roberts NB, Caldwell GA, O’Donnell JM. Invertebrate models of dystonia. Curr Neuropharmacol 2013; 11:16-29. [PMID: 23814534 PMCID: PMC3580786 DOI: 10.2174/157015913804999504] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2012] [Revised: 06/02/2012] [Accepted: 07/03/2012] [Indexed: 01/15/2023] Open
Abstract
The neurological movement disorder dystonia is an umbrella term for a heterogeneous group of related conditions where at least 20 monogenic forms have been identified. Despite the substantial advances resulting from the identification of these loci, the function of many DYT gene products remains unclear. Comparative genomics using simple animal models to examine the evolutionarily conserved functional relationships with monogenic dystonias represents a rapid route toward a comprehensive understanding of these movement disorders. Current studies using the invertebrate animal models Caenorhabditis elegans and Drosophila melanogaster are uncovering cellular functions and mechanisms associated with mutant forms of the well-conserved gene products corresponding to DYT1, DYT5a, DYT5b, and DYT12 dystonias. Here we review recent findings from the invertebrate literature pertaining to molecular mechanisms of these gene products, torsinA, GTP cyclohydrolase I, tyrosine hydroxylase, and the alpha subunit of Na+/K ATPase, respectively. In each study, the application of powerful genetic tools developed over decades of intensive work with both of these invertebrate systems has led to mechanistic insights into these human disorders. These models are particularly amenable to large-scale genetic screens for modifiers or additional alleles, which are bolstering our understanding of the molecular functions associated with these gene products. Moreover, the use of invertebrate models for the evaluation of DYT genetic loci and their genetic interaction networks has predictive value and can provide a path forward for therapeutic intervention.
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Affiliation(s)
- Kim A Caldwell
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA
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27
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Du J, Teng RJ, Lawrence M, Guan T, Xu H, Ge Y, Shi Y. The protein partners of GTP cyclohydrolase I in rat organs. PLoS One 2012; 7:e33991. [PMID: 22479495 PMCID: PMC3313957 DOI: 10.1371/journal.pone.0033991] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Accepted: 02/22/2012] [Indexed: 02/03/2023] Open
Abstract
Objective GTP cyclohydrolase I (GCH1) is the rate-limiting enzyme for tetrahydrobiopterin biosynthesis and has been shown to be a promising therapeutic target in ischemic heart disease, hypertension, atherosclerosis and diabetes. The endogenous GCH1-interacting partners have not been identified. Here, we determined endogenous GCH1-interacting proteins in rat. Methods and Results A pulldown and proteomics approach were used to identify GCH1 interacting proteins in rat liver, brain, heart and kidney. We demonstrated that GCH1 interacts with at least 17 proteins including GTP cyclohydrolase I feedback regulatory protein (GFRP) in rat liver by affinity purification followed by proteomics and validated six protein partners in liver, brain, heart and kidney by immunoblotting. GCH1 interacts with GFRP and very long-chain specific acyl-CoA dehydrogenase in the liver, tubulin beta-2A chain in the liver and brain, DnaJ homolog subfamily A member 1 and fatty aldehyde dehydrogenase in the liver, heart and kidney and eukaryotic translation initiation factor 3 subunit I (EIF3I) in all organs tested. Furthermore, GCH1 associates with mitochondrial proteins and GCH1 itself locates in mitochondria. Conclusion GCH1 interacts with proteins in an organ dependant manner and EIF3I might be a general regulator of GCH1. Our finding indicates GCH1 might have broader functions beyond tetrahydrobiopterin biosynthesis.
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Affiliation(s)
- Jianhai Du
- Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- * E-mail: (JD); (YS)
| | - Ru-Jeng Teng
- Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Matt Lawrence
- Human Proteomics Program and Department of Physiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Tongju Guan
- Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Hao Xu
- Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Ying Ge
- Human Proteomics Program and Department of Physiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Yang Shi
- Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Patient Centered Research, Aurora Health Care, Milwaukee, Wisconsin, United States of America
- * E-mail: (JD); (YS)
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Neckameyer WS, Bhatt P. Neurotrophic actions of dopamine on the development of a serotonergic feeding circuit in Drosophila melanogaster. BMC Neurosci 2012; 13:26. [PMID: 22413901 PMCID: PMC3364880 DOI: 10.1186/1471-2202-13-26] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 03/13/2012] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND In the fruit fly, Drosophila melanogaster, serotonin functions both as a neurotransmitter to regulate larval feeding, and in the development of the stomatogastric feeding circuit. There is an inverse relationship between neuronal serotonin levels during late embryogenesis and the complexity of the serotonergic fibers projecting from the larval brain to the foregut, which correlate with perturbations in feeding, the functional output of the circuit. Dopamine does not modulate larval feeding, and dopaminergic fibers do not innervate the larval foregut. Since dopamine can function in central nervous system development, separate from its role as a neurotransmitter, the role of neuronal dopamine was assessed on the development, and mature function, of the 5-HT larval feeding circuit. RESULTS Both decreased and increased neuronal dopamine levels in late embryogenesis during development of this circuit result in depressed levels of larval feeding. Perturbations in neuronal dopamine during this developmental period also result in greater branch complexity of the serotonergic fibers innervating the gut, as well as increased size and number of the serotonin-containing vesicles along the neurite length. This neurotrophic action for dopamine is modulated by the D2 dopamine receptor expressed during late embryogenesis in central 5-HT neurons. Animals carrying transgenic RNAi constructs to knock down both dopamine and serotonin synthesis in the central nervous system display normal feeding and fiber architecture. However, disparate levels of neuronal dopamine and serotonin during development of the circuit result in abnormal gut fiber architecture and feeding behavior. CONCLUSIONS These results suggest that dopamine can exert a direct trophic influence on the development of a specific neural circuit, and that dopamine and serotonin may interact with each other to generate the neural architecture necessary for normal function of the circuit.
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Affiliation(s)
- Wendi S Neckameyer
- Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, 1402 South Grand Boulevard, Saint Louis, Missouri 63104, USA
| | - Parag Bhatt
- Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, 1402 South Grand Boulevard, Saint Louis, Missouri 63104, USA
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29
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Wang Z, Ferdousy F, Lawal H, Huang Z, Daigle JG, Izevbaye I, Doherty O, Thomas J, Stathakis DG, O'Donnell JM. Catecholamines up integrates dopamine synthesis and synaptic trafficking. J Neurochem 2011; 119:1294-305. [PMID: 21985068 DOI: 10.1111/j.1471-4159.2011.07517.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The highly reactive nature of dopamine renders dopaminergic neurons vulnerable to oxidative damage. We recently demonstrated that loss-of-function mutations in the Drosophila gene Catecholamines up (Catsup) elevate dopamine pools but, paradoxically, also confer resistance to paraquat, an herbicide that induces oxidative stress-mediated toxicity in dopaminergic neurons. We now report a novel association of the membrane protein, Catsup, with GTP cyclohydrolase rate-limiting enzyme for tetrahydrobiopterin (BH(4)) biosynthesis and tyrosine hydroxylase, rate-limiting enzyme for dopamine biosynthesis, which requires BH(4) as a cofactor. Loss-of-function Catsup mutations cause dominant hyperactivation of both enzymes. Elevated dopamine levels in Catsup mutants coincide with several distinct characteristics, including hypermobility, minimal basal levels of 3,4-dihydroxy-phenylacetic acid, an oxidative metabolite of dopamine, and resistance to the vesicular monoamine transporter inhibitor, reserpine, suggesting that excess dopamine is synaptically active and that Catsup functions in the regulation of synaptic vesicle loading and release of dopamine. We conclude that Catsup regulates and links the dopamine synthesis and transport networks.
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Affiliation(s)
- Zhe Wang
- Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama 35487, USA
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30
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Abstract
Understanding and consequently treating neuropathic pain effectively is a challenge for modern medicine, as unlike inflammation, which can be controlled relatively well, chronic pain due to nerve injury is refractory to most current therapeutics. Here we define a target pathway for a new class of analgesics, tetrahydrobiopterin (BH4) synthesis and metabolism. BH4 is an essential co-factor in the synthesis of serotonin, dopamine, epinephrine, norepinephrine and nitric oxide and as a result, its availability influences many systems, including neurons. Following peripheral nerve damage, levels of BH4 are dramatically increased in sensory neurons, consequently this has a profound effect on the physiology of these cells, causing increased activity and pain hypersensitivity. These changes are principally due to the upregulation of the rate limiting enzyme for BH4 synthesis GTP Cyclohydrolase 1 (GCH1). A GCH1 pain-protective haplotype which decreases pain levels in a variety of settings, by reducing the levels of endogenous activation of this enzyme, has been characterized in humans. Here we define the control of BH4 homeostasis and discuss the consequences of large perturbations within this system, both negatively via genetic mutations and after pathological increases in the production of this cofactor that result in chronic pain. We explain the nature of the GCH1 reduced-function haplotype and set out the potential for a ' BH4 blocking' drug as a novel analgesic.
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Affiliation(s)
- Alban Latremoliere
- F.M. Kirby Neurobiology Center, Children’s Hospital Boston, Harvard Medical School, 3 Blackfan Circle, CLS 12260, Boston, MA 02115, USA
| | - Michael Costigan
- F.M. Kirby Neurobiology Center, Children’s Hospital Boston, Harvard Medical School, 3 Blackfan Circle, CLS 12260, Boston, MA 02115, USA
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31
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Abstract
BH4 (6R-L-erythro-5,6,7,8-tetrahydrobiopterin) is an essential cofactor of a set of enzymes that are of central metabolic importance, including four aromatic amino acid hydroxylases, alkylglycerol mono-oxygenase and three NOS (NO synthase) isoenzymes. Consequently, BH4 is present in probably every cell or tissue of higher organisms and plays a key role in a number of biological processes and pathological states associated with monoamine neurotransmitter formation, cardiovascular and endothelial dysfunction, the immune response and pain sensitivity. BH4 is formed de novo from GTP via a sequence of three enzymatic steps carried out by GTP cyclohydrolase I, 6-pyruvoyltetrahydropterin synthase and sepiapterin reductase. An alternative or salvage pathway involves dihydrofolate reductase and may play an essential role in peripheral tissues. Cofactor regeneration requires pterin-4a-carbinolamine dehydratase and dihydropteridine reductase, except for NOSs, in which the BH4 cofactor undergoes a one-electron redox cycle without the need for additional regeneration enzymes. With regard to the regulation of cofactor biosynthesis, the major controlling point is GTP cyclohydrolase I. BH4 biosynthesis is controlled in mammals by hormones and cytokines. BH4 deficiency due to autosomal recessive mutations in all enzymes, except for sepiapterin reductase, has been described as a cause of hyperphenylalaninaemia. A major contributor to vascular dysfunction associated with hypertension, ischaemic reperfusion injury, diabetes and others, appears to be an effect of oxidized BH4, which leads to an increased formation of oxygen-derived radicals instead of NO by decoupled NOS. Furthermore, several neurological diseases have been suggested to be a consequence of restricted cofactor availability, and oral cofactor replacement therapy to stabilize mutant phenylalanine hydroxylase in the BH4-responsive type of hyperphenylalaninaemia has an advantageous effect on pathological phenylalanine levels in patients.
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Affiliation(s)
- Ernst R Werner
- Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck A-6020, Austria
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32
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Abbas CA, Sibirny AA. Genetic control of biosynthesis and transport of riboflavin and flavin nucleotides and construction of robust biotechnological producers. Microbiol Mol Biol Rev 2011; 75:321-60. [PMID: 21646432 PMCID: PMC3122625 DOI: 10.1128/mmbr.00030-10] [Citation(s) in RCA: 239] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Riboflavin [7,8-dimethyl-10-(1'-d-ribityl)isoalloxazine, vitamin B₂] is an obligatory component of human and animal diets, as it serves as the precursor of flavin coenzymes, flavin mononucleotide, and flavin adenine dinucleotide, which are involved in oxidative metabolism and other processes. Commercially produced riboflavin is used in agriculture, medicine, and the food industry. Riboflavin synthesis starts from GTP and ribulose-5-phosphate and proceeds through pyrimidine and pteridine intermediates. Flavin nucleotides are synthesized in two consecutive reactions from riboflavin. Some microorganisms and all animal cells are capable of riboflavin uptake, whereas many microorganisms have distinct systems for riboflavin excretion to the medium. Regulation of riboflavin synthesis in bacteria occurs by repression at the transcriptional level by flavin mononucleotide, which binds to nascent noncoding mRNA and blocks further transcription (named the riboswitch). In flavinogenic molds, riboflavin overproduction starts at the stationary phase and is accompanied by derepression of enzymes involved in riboflavin synthesis, sporulation, and mycelial lysis. In flavinogenic yeasts, transcriptional repression of riboflavin synthesis is exerted by iron ions and not by flavins. The putative transcription factor encoded by SEF1 is somehow involved in this regulation. Most commercial riboflavin is currently produced or was produced earlier by microbial synthesis using special selected strains of Bacillus subtilis, Ashbya gossypii, and Candida famata. Whereas earlier RF overproducers were isolated by classical selection, current producers of riboflavin and flavin nucleotides have been developed using modern approaches of metabolic engineering that involve overexpression of structural and regulatory genes of the RF biosynthetic pathway as well as genes involved in the overproduction of the purine precursor of riboflavin, GTP.
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Affiliation(s)
| | - Andriy A. Sibirny
- Institute of Cell Biology, NAS of Ukraine, Lviv 79005, Ukraine
- University of Rzeszow, Rzeszow 35-601, Poland
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33
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Divergence in enzyme regulation between Caenorhabditis elegans and human tyrosine hydroxylase, the key enzyme in the synthesis of dopamine. Biochem J 2011; 434:133-41. [DOI: 10.1042/bj20101561] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
TH (tyrosine hydroxylase) is the rate-limiting enzyme in the synthesis of catecholamines. The cat-2 gene of the nematode Caenorhabditis elegans is expressed in mechanosensory dopaminergic neurons and has been proposed to encode a putative TH. In the present paper, we report the cloning of C. elegans full-length cat-2 cDNA and a detailed biochemical characterization of the encoded CAT-2 protein. Similar to other THs, C. elegans CAT-2 is composed of an N-terminal regulatory domain followed by a catalytic domain and a C-terminal oligomerization domain and shows high substrate specificity for L-tyrosine. Like hTH (human TH), CAT-2 is tetrameric and is phosphorylated at Ser35 (equivalent to Ser40 in hTH) by PKA (cAMP-dependent protein kinase). However, CAT-2 is devoid of characteristic regulatory mechanisms present in hTH, such as negative co-operativity for the cofactor, substrate inhibition or feedback inhibition exerted by catecholamines, end-products of the pathway. Thus TH activity in C. elegans displays a weaker regulation in comparison with the human orthologue, resembling a constitutively active enzyme. Overall, our data suggest that the intricate regulation characteristic of mammalian TH might have evolved from more simple models to adjust to the increasing complexity of the higher eukaryotes neuroendocrine systems.
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Daubner SC, Le T, Wang S. Tyrosine hydroxylase and regulation of dopamine synthesis. Arch Biochem Biophys 2010; 508:1-12. [PMID: 21176768 DOI: 10.1016/j.abb.2010.12.017] [Citation(s) in RCA: 623] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 12/13/2010] [Accepted: 12/15/2010] [Indexed: 01/22/2023]
Abstract
Tyrosine hydroxylase is the rate-limiting enzyme of catecholamine biosynthesis; it uses tetrahydrobiopterin and molecular oxygen to convert tyrosine to DOPA. Its amino terminal 150 amino acids comprise a domain whose structure is involved in regulating the enzyme's activity. Modes of regulation include phosphorylation by multiple kinases at four different serine residues, and dephosphorylation by two phosphatases. The enzyme is inhibited in feedback fashion by the catecholamine neurotransmitters. Dopamine binds to TyrH competitively with tetrahydrobiopterin, and interacts with the R domain. TyrH activity is modulated by protein-protein interactions with enzymes in the same pathway or the tetrahydrobiopterin pathway, structural proteins considered to be chaperones that mediate the neuron's oxidative state, and the protein that transfers dopamine into secretory vesicles. TyrH is modified in the presence of NO, resulting in nitration of tyrosine residues and the glutathionylation of cysteine residues.
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Affiliation(s)
- S Colette Daubner
- Department of Biological Sciences, St. Mary's University, San Antonio, TX 78228, USA.
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35
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Higgins CE, Gross SS. The N-terminal peptide of mammalian GTP cyclohydrolase I is an autoinhibitory control element and contributes to binding the allosteric regulatory protein GFRP. J Biol Chem 2010; 286:11919-28. [PMID: 21163945 DOI: 10.1074/jbc.m110.196204] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
GTP cyclohydrolase I (GTPCH) is the rate-limiting enzyme for biosynthesis of tetrahydrobiopterin (BH4), an obligate cofactor for NO synthases and aromatic amino acid hydroxylases. BH4 can limit its own synthesis by triggering decameric GTPCH to assemble in an inhibitory complex with two GTPCH feedback regulatory protein (GFRP) pentamers. Subsequent phenylalanine binding to the GTPCH·GFRP inhibitory complex converts it to a stimulatory complex. An N-terminal inhibitory peptide in GTPCH may also contribute to autoregulation of GTPCH activity, but mechanisms are undefined. To characterize potential regulatory actions of the N-terminal peptide in rat GTPCH, we expressed, purified, and characterized a truncation mutant, devoid of 45 N-terminal amino acids (Δ45-GTPCH) and contrasted its catalytic and GFRP binding properties to wild type GTPCH (wt-GTPCH). Contrary to prior reports, we show that GFRP binds wt-GTPCH in the absence of any small molecule effector, resulting in allosteric stimulation of GTPCH activity: a 20% increase in Vmax, 50% decrease in KmGTP, and increase in Hill coefficient to 1.6, from 1.0. These features of GFRP-stimulated wt-GTPCH activity were phenocopied by Δ45-GTPCH in the absence of bound GFRP. Addition of GFRP to Δ45-GTPCH failed to elicit complex formation or a substantial further increase in GTPCH catalytic activity. Expression of Δ45-GTPCH in HEK-293 cells elicited 3-fold greater BH4 accumulation than an equivalent of wt-GTPCH. Together, results indicate that the N-terminal peptide exerts autoinhibitory control over rat GTPCH and is required for GFRP binding on its own. Displacement of the autoinhibitory peptide provides a molecular mechanism for physiological up-regulation of GTPCH activity.
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Affiliation(s)
- Christina E Higgins
- Department of Pharmacology, Weill Medical College of Cornell University, New York, NY 10021, USA
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36
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Cartier EA, Parra LA, Baust TB, Quiroz M, Salazar G, Faundez V, Egaña L, Torres GE. A biochemical and functional protein complex involving dopamine synthesis and transport into synaptic vesicles. J Biol Chem 2009; 285:1957-66. [PMID: 19903816 DOI: 10.1074/jbc.m109.054510] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Synaptic transmission depends on neurotransmitter pools stored within vesicles that undergo regulated exocytosis. In the brain, the vesicular monoamine transporter-2 (VMAT(2)) is responsible for the loading of dopamine (DA) and other monoamines into synaptic vesicles. Prior to storage within vesicles, DA synthesis occurs at the synaptic terminal in a two-step enzymatic process. First, the rate-limiting enzyme tyrosine hydroxylase (TH) converts tyrosine to di-OH-phenylalanine. Aromatic amino acid decarboxylase (AADC) then converts di-OH-phenylalanine into DA. Here, we provide evidence that VMAT(2) physically and functionally interacts with the enzymes responsible for DA synthesis. In rat striata, TH and AADC co-immunoprecipitate with VMAT(2), whereas in PC 12 cells, TH co-immunoprecipitates with the closely related VMAT(1) and with overexpressed VMAT(2). GST pull-down assays further identified three cytosolic domains of VMAT(2) involved in the interaction with TH and AADC. Furthermore, in vitro binding assays demonstrated that TH directly interacts with VMAT(2). Additionally, using fractionation and immunoisolation approaches, we demonstrate that TH and AADC associate with VMAT(2)-containing synaptic vesicles from rat brain. These vesicles exhibited specific TH activity. Finally, the coupling between synthesis and transport of DA into vesicles was impaired in the presence of fragments involved in the VMAT(2)/TH/AADC interaction. Taken together, our results indicate that DA synthesis can occur at the synaptic vesicle membrane, where it is physically and functionally coupled to VMAT(2)-mediated transport into vesicles.
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Affiliation(s)
- Etienne A Cartier
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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High dose cabergoline in management of ovarian hyperstimulation syndrome. Fertil Steril 2009; 92:1168.e1-1168.e4. [PMID: 19539908 DOI: 10.1016/j.fertnstert.2009.05.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2009] [Revised: 05/06/2009] [Accepted: 05/07/2009] [Indexed: 01/11/2023]
Abstract
OBJECTIVE To describe a case of moderate ovarian hyperstimulation syndrome (OHSS) that was treated with high dose cabergoline. DESIGN Case report. SETTING Private assisted reproduction center. PATIENT(S) A 29-year-old woman who developed early moderate OHSS despite preventive cabergoline administration (0.5 mg/day) following controlled ovarian hyperstimulation for IVF treatment. INTERVENTION(S) Cabergoline dose was increased to 1 mg/day upon diagnosis of OHSS on the second day after oocyte collection and embryo transfer was postponed to the fifth day after oocyte collection. MAIN OUTCOME MEASURE(S) Resolution of OHSS and achievement of healthy live birth. RESULT(S) OHSS resolved rapidly despite occurrence of pregnancy and patient delivered a healthy boy at term. CONCLUSION(S) The higher cabergoline dose might have prevented an increase in the severity of OHSS and its prolongation following occurrence of pregnancy. Randomized controlled trials assessing the efficacy and safety of different doses and durations of cabergoline administration in both prophylactic and therapeutic settings are required.
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Chiarini A, Armato U, Pacchiana R, Dal Pra I. Proteomic analysis of GTP cyclohydrolase 1 multiprotein complexes in cultured normal adult human astrocytes under both basal and cytokine-activated conditions. Proteomics 2009; 9:1850-60. [PMID: 19294699 DOI: 10.1002/pmic.200800561] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Indexed: 12/28/2022]
Abstract
GTP cyclohydrolase 1 (GCH1) is the rate-limiting enzyme of a metabolic pathway synthesizing tetrahydrobiopterin (BH(4)), the cofactor dimerizing and activating inducible nitric oxide synthase (NOS-2). GCH1 protein expression and enzyme activity are minimal in cultured, phenotypically stable, untreated normal adult human astrocytes (NAHA), but are strongly induced, together with NOS-2, by a mixture of three proinflammatory cytokines (IL-1beta, TNF-alpha, and IFN-gamma--the CM-trio) released by microglia under brain-damaging conditions. The resulting hyper-production of NO severely harms neurons. In this study, using MALDI-TOF/MS, PMF, Western immunoblotting (WB), and antibody microarrays we identified several proteins coimmunoprecipitating with GCH1. Under basal conditions, GCH1 was associated with various adaptor/regulator molecules involved in G-protein-coupled receptors signalling, protein serine/threonine phosphatase 2Cbeta (PP2Cbeta), and serine-threonine kinases like Ca(2+) calmodulin kinases (CaMKs), casein kinases (CKs), cAMP-dependent kinases (PKAs), and mitogen-activated protein kinases (MAPKs). Exposure to the three cytokines' mixture (CM-trio) significantly changed, within the 48-72 h required for the induction and activation of GCH1, the levels and identities of some of the 0 h-associated proteins: after 72 h CK-IIalpha tended to dissociate from, whereas MAPK12 and JNK3 were strongly associated with fully active GCH1. These findings provide a first enticing glimpse into the intricate mechanisms regulating GCH1 activation by proinflammatory cytokines in NAHA, and may have therapeutic implications.
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Affiliation(s)
- Anna Chiarini
- Department of Biomedical and Surgical Sciences, Histology and Embryology Unit, University of Verona Medical School, Verona, Italy.
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