1
|
Chaudhary D, Chong F, Neupane T, Choi J, Jee JG. New Inhibitors of Laccase and Tyrosinase by Examination of Cross-Inhibition between Copper-Containing Enzymes. Int J Mol Sci 2021; 22:13661. [PMID: 34948458 DOI: 10.3390/ijms222413661] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/17/2021] [Accepted: 12/17/2021] [Indexed: 11/23/2022] Open
Abstract
Coppers play crucial roles in the maintenance homeostasis in living species. Approximately 20 enzyme families of eukaryotes and prokaryotes are known to utilize copper atoms for catalytic activities. However, small-molecule inhibitors directly targeting catalytic centers are rare, except for those that act against tyrosinase and dopamine-β-hydroxylase (DBH). This study tested whether known tyrosinase inhibitors can inhibit the copper-containing enzymes, ceruloplasmin, DBH, and laccase. While most small molecules minimally reduced the activities of ceruloplasmin and DBH, aside from known inhibitors, 5 of 28 tested molecules significantly inhibited the function of laccase, with the Ki values in the range of 15 to 48 µM. Enzyme inhibitory kinetics classified the molecules as competitive inhibitors, whereas differential scanning fluorimetry and fluorescence quenching supported direct bindings. To the best of our knowledge, this is the first report on organic small-molecule inhibitors for laccase. Comparison of tyrosinase and DBH inhibitors using cheminformatics predicted that the presence of thione moiety would suffice to inhibit tyrosinase. Enzyme assays confirmed this prediction, leading to the discovery of two new dual tyrosinase and DBH inhibitors.
Collapse
|
2
|
Osorio-Forero A, Cardis R, Vantomme G, Guillaume-Gentil A, Katsioudi G, Devenoges C, Fernandez LMJ, Lüthi A. Noradrenergic circuit control of non-REM sleep substates. Curr Biol 2021; 31:5009-5023.e7. [PMID: 34648731 DOI: 10.1016/j.cub.2021.09.041] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 08/09/2021] [Accepted: 09/15/2021] [Indexed: 12/13/2022]
Abstract
To understand what makes sleep vulnerable in disease, it is useful to look at how wake-promoting mechanisms affect healthy sleep. Wake-promoting neuronal activity is inhibited during non-rapid-eye-movement sleep (NREMS). However, sensory vigilance persists in NREMS in animals and humans, suggesting that wake promotion could remain functional. Here, we demonstrate that consolidated mouse NREMS is a brain state with recurrent fluctuations of the wake-promoting neurotransmitter noradrenaline on the ∼50-s timescale in the thalamus. These fluctuations occurred around mean noradrenaline levels greater than the ones of quiet wakefulness, while noradrenaline (NA) levels declined steeply in REMS. They coincided with a clustering of sleep spindle rhythms in the forebrain and with heart-rate variations, both of which are correlates of sensory arousability. We addressed the origins of these fluctuations by using closed-loop optogenetic locus coeruleus (LC) activation or inhibition timed to moments of low and high spindle activity during NREMS. We could suppress, lock, or entrain sleep-spindle clustering and heart-rate variations, suggesting that both fore- and hindbrain-projecting LC neurons show coordinated infraslow activity variations in natural NREMS. Noradrenergic modulation of thalamic, but not cortical, circuits was required for sleep-spindle clustering and involved NA release into primary sensory and reticular thalamic nuclei that activated both α1- and β-adrenergic receptors to cause slowly decaying membrane depolarizations. Noradrenergic signaling by LC constitutes a vigilance-promoting mechanism that renders mammalian NREMS vulnerable to disruption on the close-to-minute timescale through sustaining thalamocortical and autonomic sensory arousability. VIDEO ABSTRACT.
Collapse
Affiliation(s)
- Alejandro Osorio-Forero
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland
| | - Romain Cardis
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland
| | - Gil Vantomme
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland
| | - Aurélie Guillaume-Gentil
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland
| | - Georgia Katsioudi
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland
| | - Christiane Devenoges
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland
| | - Laura M J Fernandez
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland
| | - Anita Lüthi
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland.
| |
Collapse
|
3
|
Sun Z, Bo Q, Mao Z, Li F, He F, Pao C, Li W, He Y, Ma X, Wang C. Reduced Plasma Dopamine-β-Hydroxylase Activity Is Associated With the Severity of Bipolar Disorder: A Pilot Study. Front Psychiatry 2021; 12:566091. [PMID: 33995135 PMCID: PMC8115127 DOI: 10.3389/fpsyt.2021.566091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 03/29/2021] [Indexed: 12/11/2022] Open
Abstract
Dopamine-β-hydroxylase (DβH) is an enzyme converting dopamine to norepinephrine, a key neurotransmitter in mood disorders, such as major depressive disorder (MDD) and bipolar disorder (BD). Due to overlapping symptomology of unipolar and bipolar depression, the present study attempted to explorer if the plasma DβH activity could discriminate the depressive episodes of BD from MDD. The aim of this study was to compare the plasma DβH activity among MDD patients (n = 104), BD patients (n = 101), and healthy controls (n = 160). Clinical characteristics and cognitive function were assessed using the Young Mania Rating Scale (YMRS), Hamilton Depression Scale (HAM-D), Hamilton Anxiety Scale (HAM-A), Patient Health Questionnaire-9 (PHQ-9), and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Our data showed a lower plasma DβH activity in patients with BD, not MDD, than that in controls. For the BD patients, the plasma DβH activities were negatively correlated with HAM-D scores and HAM-A scores. However, there was no significant correlation between plasma DβH activity and severity of depressive symptoms in MDD patients. No significant correlation between DβH activities and cognitive assessments neither in BD nor in MDD patients. The present study provides evidence that BD is associated with decreased circulating DβH activity.
Collapse
Affiliation(s)
- Zuoli Sun
- The National Clinical Research Center for Mental Disorders and Beijing Key Laboratory of Mental Disorders and Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Qijing Bo
- The National Clinical Research Center for Mental Disorders and Beijing Key Laboratory of Mental Disorders and Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Zhen Mao
- The National Clinical Research Center for Mental Disorders and Beijing Key Laboratory of Mental Disorders and Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Feng Li
- The National Clinical Research Center for Mental Disorders and Beijing Key Laboratory of Mental Disorders and Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Fan He
- The National Clinical Research Center for Mental Disorders and Beijing Key Laboratory of Mental Disorders and Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Christine Pao
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Wenbiao Li
- The National Clinical Research Center for Mental Disorders and Beijing Key Laboratory of Mental Disorders and Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China
| | - Yi He
- The National Clinical Research Center for Mental Disorders and Beijing Key Laboratory of Mental Disorders and Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Xin Ma
- The National Clinical Research Center for Mental Disorders and Beijing Key Laboratory of Mental Disorders and Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Chuanyue Wang
- The National Clinical Research Center for Mental Disorders and Beijing Key Laboratory of Mental Disorders and Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| |
Collapse
|
4
|
Schmidt K, Ralle M, Schaffer T, Jayakanthan S, Bari B, Muchenditsi A, Lutsenko S. ATP7A and ATP7B copper transporters have distinct functions in the regulation of neuronal dopamine-β-hydroxylase. J Biol Chem 2018; 293:20085-20098. [PMID: 30341172 DOI: 10.1074/jbc.ra118.004889] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/17/2018] [Indexed: 01/06/2023] Open
Abstract
The copper (Cu) transporters ATPase copper-transporting alpha (ATP7A) and ATPase copper-transporting beta (ATP7B) are essential for the normal function of the mammalian central nervous system. Inactivation of ATP7A or ATP7B causes the severe neurological disorders, Menkes disease and Wilson disease, respectively. In both diseases, Cu imbalance is associated with abnormal levels of the catecholamine-type neurotransmitters dopamine and norepinephrine. Dopamine is converted to norepinephrine by dopamine-β-hydroxylase (DBH), which acquires its essential Cu cofactor from ATP7A. However, the role of ATP7B in catecholamine homeostasis is unclear. Here, using immunostaining of mouse brain sections and cultured cells, we show that DBH-containing neurons express both ATP7A and ATP7B. The two transporters are located in distinct cellular compartments and oppositely regulate the export of soluble DBH from cultured neuronal cells under resting conditions. Down-regulation of ATP7A, overexpression of ATP7B, and pharmacological Cu depletion increased DBH retention in cells. In contrast, ATP7B inactivation elevated extracellular DBH. Proteolytic processing and the specific activity of exported DBH were not affected by changes in ATP7B levels. These results establish distinct regulatory roles for ATP7A and ATP7B in neuronal cells and explain, in part, the lack of functional compensation between these two transporters in human disorders of Cu imbalance.
Collapse
Affiliation(s)
- Katharina Schmidt
- From the Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Martina Ralle
- the Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon 97239
| | - Thomas Schaffer
- the Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland 21205, and
| | - Samuel Jayakanthan
- From the Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Bilal Bari
- the Department of Neuroscience, Brain Science Institute, Johns Hopkins University, Baltimore, Maryland 21205
| | - Abigael Muchenditsi
- From the Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Svetlana Lutsenko
- From the Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205,.
| |
Collapse
|
5
|
Mohammed M, Kulasekara K, Ootsuka Y, Blessing WW. Locus coeruleus noradrenergic innervation of the amygdala facilitates alerting-induced constriction of the rat tail artery. Am J Physiol Regul Integr Comp Physiol 2016; 310:R1109-19. [PMID: 27101292 DOI: 10.1152/ajpregu.00058.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 04/11/2016] [Indexed: 02/08/2023]
Abstract
The amygdala, innervated by the noradrenergic locus coeruleus, processes salient environmental events. α2-adrenoceptor-stimulating drugs (clonidine-like agents) suppress the behavioral and physiological components of the response to salient events. Activation of sympathetic outflow to the cutaneous vascular bed is part of the physiological response to salience-mediated activation of the amygdala. We have determined whether acute systemic and intra-amygdala administration of clonidine, and chronic immunotoxin-mediated destruction of the noradrenergic innervation of the amygdala, impairs salience-related vasoconstrictor episodes in the tail artery of conscious freely moving Sprague-Dawley rats. After acute intraperitoneal injection of clonidine (10, 50, and 100 μg/kg), there was a dose-related decrease in the reduction in tail blood flow elicited by alerting stimuli, an effect prevented by prior administration of the α2-adrenergic blocking drug idazoxan (1 mg/kg ip or 75 nmol bilateral intra-amygdala). A dose-related decrease in alerting-induced tail artery vasoconstriction was also observed after bilateral intra-amygdala injection of clonidine (5, 10, and 20 nmol in 200 nl), an effect substantially prevented by prior bilateral intra-amygdala injection of idazoxan. Intra-amygdala injection of idazoxan by itself did not alter tail artery vasoconstriction elicited by alerting stimuli. Intra-amygdala injection of saporin coupled to antibodies to dopamine-β-hydroxylase (immunotoxin) destroyed the noradrenergic innervation of the amygdala and the parent noradrenergic neurons in the locus coeruleus. The reduction in tail blood flow elicited by standardized alerting stimuli was substantially reduced in immunotoxin-treated rats. Thus, inhibiting the release of noradrenaline within the amygdala reduces activation of the sympathetic outflow to the vascular beds elicited by salient events.
Collapse
Affiliation(s)
- Mazher Mohammed
- Centre for Neuroscience, Department of Human Physiology, Flinders University, Adelaide, South Australia, Australia
| | - Keerthi Kulasekara
- Centre for Neuroscience, Department of Human Physiology, Flinders University, Adelaide, South Australia, Australia
| | - Youichirou Ootsuka
- Centre for Neuroscience, Department of Human Physiology, Flinders University, Adelaide, South Australia, Australia
| | - William W Blessing
- Centre for Neuroscience, Department of Human Physiology, Flinders University, Adelaide, South Australia, Australia
| |
Collapse
|
6
|
Reyes BAS, Heldt NA, Mackie K, Van Bockstaele EJ. Ultrastructural evidence for synaptic contacts between cortical noradrenergic afferents and endocannabinoid-synthesizing post-synaptic neurons. Neuroscience 2015; 303:323-37. [PMID: 26162236 PMCID: PMC4542008 DOI: 10.1016/j.neuroscience.2015.07.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 06/12/2015] [Accepted: 07/01/2015] [Indexed: 01/31/2023]
Abstract
Endocannabinoids (eCBs) are involved in a myriad of physiological processes that are mediated through the activation of cannabinoid receptors, which are ubiquitously distributed within the nervous system. One neurochemical target at which cannabinoids interact to have global effects on behavior is brain noradrenergic circuitry. We, and others, have previously shown that CB type 1 receptors (CB1r) are positioned to pre-synaptically modulate norepinephrine (NE) release in the rat frontal cortex (FC). Diacylglycerol lipase (DGL) is a key enzyme in the biosynthesis of the endocannabinoid 2-arachidonoylglycerol (2-AG). While DGL-α is expressed in the FC in the rat brain, it is not known whether noradrenergic afferents target neurons expressing synthesizing enzymes for the endocannabinoid, 2-AG. In the present study, we employed high-resolution neuroanatomical approaches to better define cellular sites for interactions between noradrenergic afferents and FC neurons expressing DGL-α. Immunofluorescence microscopy showed close appositions between processes containing the norepinephrine transporter (NET) or dopamine-β-hydroxylase (DβH) and cortical neurons expressing DGL-α-immunoreactivity. Ultrastructural analysis using immunogold-silver labeling for DGL-α and immunoperoxidase labeling for NET or DβH confirmed that NET-labeled axon terminals were directly apposed to FC somata and dendritic processes that exhibited DGL-α-immunoreactivity. Finally, tissue sections were processed for immunohistochemical detection of DGL-α, CB1r and DβH. Triple label immunofluorescence revealed that CB1r and DβH were co-localized in common cellular profiles and these were in close association with DGL-α. Taken together, these data provide anatomical evidence for direct synaptic associations between noradrenergic afferents and cortical neurons exhibiting endocannabinoid synthesizing machinery.
Collapse
Affiliation(s)
- B A S Reyes
- Department of Pharmacology and Physiology, College of Medicine, Drexel University, Philadelphia, PA 19102, United States.
| | - N A Heldt
- Department of Pharmacology and Physiology, College of Medicine, Drexel University, Philadelphia, PA 19102, United States
| | - K Mackie
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, United States
| | - E J Van Bockstaele
- Department of Pharmacology and Physiology, College of Medicine, Drexel University, Philadelphia, PA 19102, United States
| |
Collapse
|
7
|
Abstract
Monoaminergic brainstem systems have widespread projections that participate in many central processes and, when dysregulated, contribute to a plethora of neuropsychiatric and neurodegenerative disorders. Synapses are the foundation of these neuronal circuits, and their local dysfunction results in global aberrations leading to pathophysiological disease states. This review focuses on the locus coeruleus (LC) norepinephrine (NE) brainstem system and its underappreciated role in Alzheimer's disease (AD). Amyloid beta (Aβ), a peptide that accumulates aberrantly in AD has recently been implicated as a modulator of neuronal excitability at the synapse. Evidence is presented showing that disruption of the LC-NE system at a synaptic and circuit level during early stages of AD, due to conditions such as chronic stress, can potentially lead to amyloid accumulation and contribute to the progression of this neurodegenerative disorder. Additional factors that impact neurodegeneration include neuroinflammation, and network de-synchronization. Consequently, targeting the LC-NE system may have significant therapeutic potential for AD, as it may facilitate modulation of Aβ production, curtail neuroinflammation, and prevent sleep and behavioral disturbances that often lead to negative patient outcomes.
Collapse
Affiliation(s)
- Jennifer A Ross
- Department of Pharmacology and Physiology, College of Medicine, Drexel University, Philadelphia, PA 19102
| | - Paul McGonigle
- Department of Pharmacology and Physiology, College of Medicine, Drexel University, Philadelphia, PA 19102
| | - Elisabeth J Van Bockstaele
- Department of Pharmacology and Physiology, College of Medicine, Drexel University, Philadelphia, PA 19102
| |
Collapse
|
8
|
Pellegrino MJ, Habecker BA. STAT3 integrates cytokine and neurotrophin signals to promote sympathetic axon regeneration. Mol Cell Neurosci 2013; 56:272-82. [PMID: 23831387 DOI: 10.1016/j.mcn.2013.06.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 06/06/2013] [Accepted: 06/25/2013] [Indexed: 12/31/2022] Open
Abstract
The transcription factor STAT3 has been implicated in axon regeneration. Here we investigate a role for STAT3 in sympathetic nerve sprouting after myocardial infarction (MI) - a common injury in humans. We show that NGF stimulates serine phosphorylation (S727) of STAT3 in sympathetic neurons via ERK1/2, in contrast to cytokine phosphorylation of Y705. Maximal sympathetic axon regeneration in vitro requires phosphorylation of both S727 and Y705. Furthermore, cytokine signaling is necessary for NGF-induced sympathetic nerve sprouting in the heart after MI. Transfection studies in neurons lacking STAT3 suggest two independent pools of STAT3, phosphorylated on either S727 or Y705, that regulate sympathetic regeneration via both transcriptional and non-transcriptional means. Additional data identify STAT3-microtubule interactions that may complement the well-characterized role of STAT3 stimulating regeneration associated genes. These data show that STAT3 is critical for sympathetic axon regeneration in vitro and in vivo, and identify a novel non-transcriptional mode of action.
Collapse
Affiliation(s)
- Michael J Pellegrino
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, OR 97239, USA
| | | |
Collapse
|
9
|
Fan Y, Huang J, Duffourc M, Kao RL, Ordway GA, Huang R, Zhu MY. Transcription factor Phox2 upregulates expression of norepinephrine transporter and dopamine β-hydroxylase in adult rat brains. Neuroscience 2011; 192:37-53. [PMID: 21763404 PMCID: PMC3166407 DOI: 10.1016/j.neuroscience.2011.07.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 07/05/2011] [Accepted: 07/06/2011] [Indexed: 01/22/2023]
Abstract
Degeneration of the noradrenergic locus coeruleus (LC) in aging and neurodegenerative diseases is well documented. Slowing or reversing this effect may have therapeutic implications. Phox2a and Phox2b are homeodomain transcriptional factors that function as determinants of the noradrenergic phenotype during embryogenesis. In the present study, recombinant lentiviral eGFP-Phox2a and -Phox2b (vPhox2a and vPhox2b) were constructed to study the effects of Phox2a/2b over-expression on dopamine β-hydroxylase (DBH) and norepinephrine transporter (NET) levels in central noradrenergic neurons. Microinjection of vPhox2 into the LC of adult rats significantly increased Phox2 mRNA levels in the LC region. Over-expression of either Phox2a or Phox2b in the LC was paralleled by significant increases in mRNA and protein levels of DBH and NET in the LC. Similar increases in DBH and NET protein levels were observed in the hippocampus following vPhox2 microinjection. In the frontal cortex, only NET protein levels were significantly increased by vPhox2 microinjection. Over-expression of Phox2 genes resulted in a significant increase in BrdU-positive cells in the hippocampal dentate gyrus. The present study demonstrates an upregulatory effect of Phox2a and Phox2b on the expression of DBH and NET in noradrenergic neurons of rat brains, an effect not previously shown in adult animals. Phox2 genes may play an important role in maintaining the function of the noradrenergic neurons after birth, and regulation of Phox2 gene expression may have therapeutic utility in aging or disorders involving degeneration of noradrenergic neurons.
Collapse
Affiliation(s)
- Yan Fan
- Department of Pharmacology, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
- Department of Biochemistry and Molecular Biology, Soochow University School of Medicine, Suzhou, China
| | - Jingjing Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Michelle Duffourc
- Department of Pharmacology, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Race L. Kao
- Department of Surgery, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Gregory A. Ordway
- Department of Pharmacology, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Rui Huang
- Department of Biochemistry and Molecular Biology, Soochow University School of Medicine, Suzhou, China
| | - Meng-Yang Zhu
- Department of Pharmacology, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| |
Collapse
|
10
|
Rahman MK, Rahman F, Rahman T, Kato T. Dopamine-β-Hydroxylase (DBH), Its Cofactors and Other Biochemical Parameters in the Serum of Neurological Patients in Bangladesh. Int J Biomed Sci 2009; 5:395-401. [PMID: 23675164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Accepted: 08/20/2009] [Indexed: 11/12/2022]
Abstract
Dopamine-β-hydroxylase (DBH) is a neurotransmitter synthesizing enzyme which catalyzes the formation of norepinephrine from dopamine. In this study, we measured the level of DBH activity in the serum of patients of three different age groups (8-14 yrs, 20-40 yrs and 45-60 yrs) suffering from neurological diseases. Serum DBH activity was measured in 38 neurological patients and 38 normal individuals in order to determine significant variables for its potential use to diagnose the neurological patients. It was found that the DBH activity decreased in the patients of all age groups. A considerable decrease in activity was observed in the patients of 8-14 yrs age group (14.2 nmoles/min/ml in patients compared to the normal value of 22.6). A significant decrease in activity was found in the 20-40 yrs age group (23.4 nmoles/min/ml in patients compared to the normal value of 33.0). The decrease in DBH activity was also found in the patients of 45-60 yrs age group but to a lesser extent (26.4 nmoles/min/ml in the patients compared to the normal value of 30.2). The kinetic studies of DBH exhibited an increase of Km value and a decrease in Vmax in the neurological patients. Serum copper and ascorbic acid levels (cofactors of DBH) were found to be decreased in neurological patients and hence are in agreement with the decrease in DBH activity in these patients. Other parameters such as glucose and cholesterol levels increased, protein and zinc levels decreased and ALT, AST, creatinine and urea content remained nearly unchanged in the patients' serum.
Collapse
|
11
|
Goswami U, Basu S, Khastgir U, Kumar U, Chandrasekaran R, Gangadhar BN, Sagar R, Bapna JS, Channabasavanna SM, Moore PB, Ferrier IN. Neurobiological characterization of bipolar affective disorders : a focus on tardive dyskinesia and soft neurological signs in relation to serum dopamine Beta hydroxylase activity. Indian J Psychiatry 1998; 40:201-11. [PMID: 21494474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In this study, the prognostic determinants were investigated involving bipolar patients classified into two groups-one with favourable course and outcome, and the other with clearly unfavourable prognosis, based on certain recommended criteria, with intermediate prognosis were excluded. As compared to the poor prognosis group, the good prognosis group had lower social dysfunctions, lower ratings on psychopathotogy fewer indicators of neurodysfunction in form of neurological soft signs (NSS) and tardive dyskinesia (TD). The poor prognosis group was characterized by: (i) older age at onset; (ii) more manic than depressive episodes (5:1) and (HI) lower levels of serum dopamine-β-hydroxylase activity (DBH). The association between poor prognosis bipolar disorder having neuroleptic intolerance (TD and NSS) with low serum DBH, suggests that it is genetically governed. Further research in this direction seems in order, particularly the follow up of first episode manic disorders.
Collapse
|
12
|
Stanley WC, Li B, Bonhaus DW, Johnson LG, Lee K, Porter S, Walker K, Martinez G, Eglen RM, Whiting RL, Hegde SS. Catecholamine modulatory effects of nepicastat (RS-25560-197), a novel, potent and selective inhibitor of dopamine-beta-hydroxylase. Br J Pharmacol 1997; 121:1803-9. [PMID: 9283721 PMCID: PMC1564872 DOI: 10.1038/sj.bjp.0701315] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
1. Inhibitory modulation of sympathetic nerve function may have a favourable impact on the progression of congestive heart failure. Nepicastat is a novel inhibitor of dopamine-beta-hydroxylase, the enzyme which catalyses the conversion of dopamine to noradrenaline in sympathetic nerves. The in vitro pharmacology and in vivo catecholamine modulatory effects of nepicastat were investigated in the present study. 2. Nepicastat produced concentration-dependent inhibition of bovine (IC50 = 8.5 +/- 0.8 nM) and human (IC50 = 9.0 +/- 0.8 nM) dopamine-beta-hydroxylase. The corresponding R-enantiomer (RS-25560-198) was approximately 2-3 fold less potent than nepicastat. Nepicastat had negligible affinity (> 10 microM) for twelve other enzymes and thirteen neurotransmitter receptors. 3. Administration of nepicastat to spontaneously hypertensive rats (SHRs) (three consecutive doses of either 3, 10, 30 or 100 mg kg-1, p.o.; 12 h apart) or beagle dogs (0.05, 0.5, 1.5 or 5 mg kg-1, p.o.; b.i.d., for 5 days) produced dose-dependent decreases in noradrenaline content, increases in dopamine content and increases in dopamine/noradrenaline ratio in the artery (mesenteric or renal), left ventricle and cerebral cortex. At the highest dose studied, the decreases in tissue noadrenaline were 47%, 35% and 42% (in SHRs) and 88%, 91% and 96% (in dogs) in the artery, left ventricle and cerebral cortex, respectively. When tested at 30 mg kg-1, p.o., in SHRs, nepicastat produced significantly greater changes in noradrenaline and dopamine content, as compared to the R-enantiomer (RS-25560-198), in the mesenteric artery and left ventricle. 4. Administration of nepicastat (2 mg kg-1, b.i.d, p.o.) to beagle dogs for 15 days produced significant decreases in plasma concentrations of noradrenaline and increases in plasma concentrations of dopamine and dopamine/noradrenaline ratio. The peak reduction (52%) in plasma concentration of noradrenaline and the peak increase (646%) in plasma concentration of dopamine were observed on day-6 and day-7 of dosing, respectively. 5. The findings of this study suggest that nepicastat is a potent, selective and orally active inhibitor of dopamine-beta-hydroxylase which produces gradual modulation of the sympathetic nervous system by inhibiting the biosynthesis of noradrenaline. This drug may, therefore, be of value in the treatment of cardiovascular disorders associated with over-activation of the sympathetic nervous system, such as congestive heart failure.
Collapse
Affiliation(s)
- W C Stanley
- Center for Biological Research, Roche Bioscience, Palo Alto, CA-94304, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Tiveron MC, Hirsch MR, Brunet JF. The expression pattern of the transcription factor Phox2 delineates synaptic pathways of the autonomic nervous system. J Neurosci 1996; 16:7649-60. [PMID: 8922421 PMCID: PMC6579082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Many transcription factors, and most prominently among them, homeodomain proteins, are expressed in specific groups of cells in the developing nervous system in patterns that suggest their involvement in neural fate determination. How various aspects of neural identity are controlled by such transcription factors, or sets of them, is still mostly unknown. It has been shown previously that Phox2 is such a homeodomain protein, expressed exclusively in differentiated groups of neurons or their precursors, and that its expression correlated with that of the noradrenaline synthesis enzyme dopamine-beta-hydroxylase. Here we confirm this striking correlation at the single-cell level with the use of an anti-Phox2 antibody. Moreover, we uncover a second, nonmutually exclusive correlative clue to the Phox2 expression pattern: a high proportion of Phox2-expressing cells are involved in, or located in areas involved in, synaptic circuits, i.e., that of the medullary control reflexes of autonomic functions. This suggests that Phox2 could be involved in the establishment of these circuits.
Collapse
Affiliation(s)
- M C Tiveron
- Institut de Biologie du Développement de Marseille, Centre National dela Recherche Scientifique--Institut National de la Santé et de la Recherche Médicale--Université de la Mediterranée, Marseille, France
| | | | | |
Collapse
|
14
|
Teitelman G, Baker H, Joh TH, Reis DJ. Appearance of catecholamine-synthesizing enzymes during development of rat sympathetic nervous system: possible role of tissue environment. Proc Natl Acad Sci U S A 1979; 76:509-13. [PMID: 34153 PMCID: PMC382971 DOI: 10.1073/pnas.76.1.509] [Citation(s) in RCA: 101] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
We sought to determine, in rat embryo, when and at what site in their migration cells derived from the neural crest differentiate into sympathetic neuroblasts. This has been accomplished by immunocytochemical detection, within the cells, of the enzymes catalyzing catecholamine biosynthesis-tyrosine hydroxylase [TH; tyrosine 3-monooxygenase, L-tyrosine, tetrahydropteridine:oxygen oxidoreductase (3-hydroxylating), EC 1.14.16.2] dopamine-beta-hydroxylase [DBH; 3,4-dihydroxyphenylethylamine,ascorbate:oxygen oxidoreductase (beta-hydroxylating), EC 1.14.17.1)]-and, as a marker of prospective adrenal medullary cells, the enzyme phenylethanolamine N-methyltransferase (PNMT; S-adenosyl-L-methionine:phenylethanolamine N-methyltransferase, EC 2.1.1.28). TH and DBH, not detected in the neural crest, appear almost simultaneously in cells of the thoracic sympathetic ganglia in 11-day-old embryos, and in abdominal and lumbar ganglia 1-2 days later, thereby exhibiting a characteristic rostral-caudal gradient of differentiation. Cells stained for TH and DBH are seen in the gut wall from day 11 to day 14, but not thereafter. Cells stained for TH and DBH appear in the adrenal anlage at day 15. However, PNMT is not detected in the adrenal until day 17 of development, and is present only in the sympathoblasts in contact with the adrenal cortex. Treatment of pregnant rats with dexamethasone failed to accelerate the appearance of PNMT in the embryo or to initiate its expression in cells of other sympathetic organs. We conclude that neural crest cells express a noradrenergic phenotype only after leaving the neural crest and that these cells are labile with respect to their neurotransmitter and are capable of transformation in response to environmental stimuli.
Collapse
|