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Hernández-Hernández E, Ledesma-Corvi S, Yáñez-Gómez F, Garau C, Gálvez-Melero L, Bagán A, Escolano C, García-Fuster MJ. Sex differences in the antidepressant-like response and molecular events induced by the imidazoline-2 receptor agonist CR4056 in rats. Pharmacol Biochem Behav 2023; 223:173527. [PMID: 36781025 DOI: 10.1016/j.pbb.2023.173527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 02/08/2023] [Accepted: 02/08/2023] [Indexed: 02/13/2023]
Abstract
In searching for novel targets to design antidepressants, among the characterized imidazoline receptors (IR), I2 receptors are an innovative therapeutical approach since they are dysregulated in major depressive disorder and by classical antidepressant treatments. In fact, several I2 agonists have been characterized for their antidepressant-like potential, but the results in terms of efficacy were mixed and exclusively reported in male rodents. Since there are well-known sex differences in antidepressant-like efficacy, this study characterized the potential effects induced by two I2 drugs, CR4056 (i.e., most promising drug already in phase II clinical trial for its analgesic properties) and B06 (a compound from a new family of bicyclic α-iminophosphonates) under the stress of the forced-swim test in male and female rats exposed to early-life stress. Moreover, some hippocampal neuroplasticity markers related to the potential effects observed were also evaluated (i.e., FADD, p-ERK/ERK, mBDNF, cell proliferation: Ki-67 + cells). The main results replicated the only prior study reporting the efficacy of CR4056 in male rats, while providing new data on its efficacy in females, which was clearly dependent on prior early-life stress exposure. Moreover, B06 showed no antidepressant-like effects in male or female rats. Finally, CR4056 increased FADD content and decreased cell proliferation in hippocampus, without affecting p-ERK/t-ERK ratio and/or mBDNF content. Interestingly, these effects were exclusively observed in female rats, and independently of early-life conditions, suggesting some distinctive molecular underpinnings participating in the therapeutic response of CR4056 for both sexes. In conjunction, these results present CR4056 with an antidepressant-like potential, especially in female rats exposed to stress early in life, together with some neuronal correlates described in the context of these behavioral changes in females.
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Affiliation(s)
- Elena Hernández-Hernández
- IUNICS, University of the Balearic Islands, Palma, Spain; Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
| | - Sandra Ledesma-Corvi
- IUNICS, University of the Balearic Islands, Palma, Spain; Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
| | - Fernando Yáñez-Gómez
- IUNICS, University of the Balearic Islands, Palma, Spain; Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
| | - Celia Garau
- IUNICS, University of the Balearic Islands, Palma, Spain; Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
| | - Laura Gálvez-Melero
- IUNICS, University of the Balearic Islands, Palma, Spain; Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
| | - Andrea Bagán
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Barcelona, Spain
| | - Carmen Escolano
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Barcelona, Spain
| | - M Julia García-Fuster
- IUNICS, University of the Balearic Islands, Palma, Spain; Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain.
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2
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Bagán A, Morales-García JA, Griñán-Ferré C, Díaz C, Pérez del Palacio J, Ramos MC, Vicente F, Pérez B, Brea J, Loza MI, Pallàs M, Escolano C. Insights into the Pharmacokinetics and In Vitro Cell-Based Studies of the Imidazoline I 2 Receptor Ligand B06. Int J Mol Sci 2022; 23:ijms23105408. [PMID: 35628219 PMCID: PMC9141032 DOI: 10.3390/ijms23105408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 05/06/2022] [Accepted: 05/06/2022] [Indexed: 02/01/2023] Open
Abstract
The impact of neurodegenerative diseases (ND) is becoming unbearable for humankind due to their vast prevalence and the lack of efficacious treatments. In this scenario, we focused on imidazoline I2 receptors (I2-IR) that are widely distributed in the brain and are altered in patients with brain disorders. We took the challenge of modulating I2-IR by developing structurally new molecules, in particular, a family of bicyclic α-iminophosphonates, endowed with high affinity and selectivity to these receptors. Treatment of two murine models, one for age-related cognitive decline and the other for Alzheimer's disease (AD), with representative compound B06 ameliorated their cognitive impairment and improved their behavioural condition. Furthermore, B06 revealed beneficial in vitro ADME-Tox properties. The pharmacokinetics (PK) and metabolic profile are reported to de-risk B06 for progressing in the preclinical development. To further characterize the pharmacological properties of B06, we assessed its neuroprotective properties and beneficial effect in an in vitro model of Parkinson's disease (PD). B06 rescued the human dopaminergic cell line SH-SY5Y from death after treatment with 6-hydroxydopamine (6-OHDA) and showed a crucial anti-inflammatory effect in a cellular model of neuroinflammation. This research reveals B06 as a putative candidate for advancing in the difficult path of drug discovery and supports the modulation of I2-IR as a fresh approach for the therapy of ND.
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Affiliation(s)
- Andrea Bagán
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, Institute of Biomedicine (IBUB), University of Barcelona, 08028 Barcelona, Spain;
| | - José A. Morales-García
- The Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Department of Cell Biology, School of Medicine, Complutense University (UCM), 28040 Madrid, Spain;
| | - Christian Griñán-Ferré
- Pharmacology Section, Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, Institut de Neurociències, University of Barcelona, 08028 Barcelona, Spain; (C.G.-F.); (M.P.)
| | - Caridad Díaz
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Avda. del Conocimiento 34, 18016 Armilla, Spain; (C.D.); (J.P.d.P.); (M.C.R.); (F.V.)
| | - José Pérez del Palacio
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Avda. del Conocimiento 34, 18016 Armilla, Spain; (C.D.); (J.P.d.P.); (M.C.R.); (F.V.)
| | - Maria C. Ramos
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Avda. del Conocimiento 34, 18016 Armilla, Spain; (C.D.); (J.P.d.P.); (M.C.R.); (F.V.)
| | - Francisca Vicente
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Avda. del Conocimiento 34, 18016 Armilla, Spain; (C.D.); (J.P.d.P.); (M.C.R.); (F.V.)
| | - Belén Pérez
- Department of Pharmacology, Therapeutic and Toxicology, Autonomous University of Barcelona, 08193 Barcelona, Spain;
| | - José Brea
- Innopharma Screening Platform, BioFarma Research Group, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidad de Santiago de Compostela, 15706 Santiago de Compostela, Spain; (J.B.); (M.I.L.)
| | - María Isabel Loza
- Innopharma Screening Platform, BioFarma Research Group, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidad de Santiago de Compostela, 15706 Santiago de Compostela, Spain; (J.B.); (M.I.L.)
| | - Mercè Pallàs
- Pharmacology Section, Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, Institut de Neurociències, University of Barcelona, 08028 Barcelona, Spain; (C.G.-F.); (M.P.)
| | - Carmen Escolano
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, Institute of Biomedicine (IBUB), University of Barcelona, 08028 Barcelona, Spain;
- Correspondence:
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Benzofuranyl-2-imidazoles as imidazoline I 2 receptor ligands for Alzheimer's disease. Eur J Med Chem 2021; 222:113540. [PMID: 34118720 DOI: 10.1016/j.ejmech.2021.113540] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/26/2021] [Accepted: 05/10/2021] [Indexed: 12/29/2022]
Abstract
Recent findings unveil the pharmacological modulation of imidazoline I2 receptors (I2-IR) as a novel strategy to face unmet medical neurodegenerative diseases. In this work, we report the chemical characterization, three-dimensional quantitative structure-activity relationship (3D-QSAR) and ADMET in silico of a family of benzofuranyl-2-imidazoles that exhibit affinity against human brain I2-IR and most of them have been predicted to be brain permeable. Acute treatment in mice with 2-(2-benzofuranyl)-2-imidazole, known as LSL60101 (garsevil), showed non-warning properties in the ADMET studies and an optimal pharmacokinetic profile. Moreover, LSL60101 induced hypothermia in mice while decreased pro-apoptotic FADD protein in the hippocampus. In vivo studies in the familial Alzheimer's disease 5xFAD murine model with the representative compound, revealed significant decreases in the protein expression levels of antioxidant enzymes superoxide dismutase and glutathione peroxidase in hippocampus. Overall, LSL60101 plays a neuroprotective role by reducing apoptosis and modulating oxidative stress.
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Evaluating the effects of 2-BFI and tracizoline, two potent I2-imidazoline receptor agonists, on cognitive performance and affect in middle-aged rats. Naunyn Schmiedebergs Arch Pharmacol 2021; 394:989-996. [DOI: 10.1007/s00210-020-02042-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/13/2020] [Indexed: 01/01/2023]
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Astroglial tracer BU99008 detects multiple binding sites in Alzheimer's disease brain. Mol Psychiatry 2021; 26:5833-5847. [PMID: 33888872 PMCID: PMC8758481 DOI: 10.1038/s41380-021-01101-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/17/2021] [Accepted: 04/01/2021] [Indexed: 12/15/2022]
Abstract
With reactive astrogliosis being established as one of the hallmarks of Alzheimer's disease (AD), there is high interest in developing novel positron emission tomography (PET) tracers to detect early astrocyte reactivity. BU99008, a novel astrocytic PET ligand targeting imidazoline-2 binding sites (I2BS) on astrocytes, might be a suitable candidate. Here we demonstrate for the first time that BU99008 could visualise reactive astrogliosis in postmortem AD brains and propose a multiple binding site [Super-high-affinity (SH), High-affinity (HA) and Low-affinity (LA)] model for BU99008, I2BS specific ligands (2-BFI and BU224) and deprenyl in AD and control (CN) brains. The proportion (%) and affinities of these sites varied significantly between the BU99008, 2-BFI, BU224 and deprenyl in AD and CN brains. Regional binding studies demonstrated significantly higher 3H-BU99008 binding in AD brain regions compared to CN. Comparative autoradiography studies reinforced these findings, showing higher specific binding for 3H-BU99008 than 3H-Deprenyl in sporadic AD brain compared to CN, implying that they might have different targets. The data clearly shows that BU99008 could detect I2BS expressing reactive astrocytes with good selectivity and specificity and hence be a potential attractive clinical astrocytic PET tracer for gaining further insight into the role of reactive astrogliosis in AD.
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Mirzaei N, Mota BC, Birch AM, Davis N, Romero-Molina C, Katsouri L, Palmer EOC, Golbano A, Riggall LJ, Nagy I, Tyacke R, Nutt DJ, Sastre M. Imidazoline ligand BU224 reverses cognitive deficits, reduces microgliosis and enhances synaptic connectivity in a mouse model of Alzheimer's disease. Br J Pharmacol 2020; 178:654-671. [PMID: 33140839 DOI: 10.1111/bph.15312] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND AND PURPOSE Activation of type 2 imidazoline receptors has been shown to exhibit neuroprotective properties including anti-apoptotic and anti-inflammatory effects, suggesting a potential therapeutic value in Alzheimer's disease (AD). Here, we explored the effects of the imidazoline-2 ligand BU224 in a model of amyloidosis. EXPERIMENTAL APPROACH Six-month-old female transgenic 5XFAD and wild-type (WT) mice were treated intraperitoneally with 5-mg·kg-1 BU224 or vehicle twice a day for 10 days. Behavioural tests were performed for cognitive functions and neuropathological changes were investigated by immunohistochemistry, Western blot, elisa and qPCR. Effects of BU224 on amyloid precursor protein (APP) processing, spine density and calcium imaging were analysed in brain organotypic cultures and N2a cells. KEY RESULTS BU224 treatment attenuated spatial and perirhinal cortex-dependent recognition memory deficits in 5XFAD mice. Fear-conditioning testing revealed that BU224 also improved both associative learning and hippocampal- and amygdala-dependent memory in transgenic but not in WT mice. In the brain, BU224 reduced levels of the microglial marker Iba1 and pro-inflammatory cytokines IL-1β and TNF-α and increased the expression of astrocytic marker GFAP in 5XFAD mice. These beneficial effects were not associated with changes in amyloid pathology, neuronal apoptosis, mitochondrial density, oxidative stress or autophagy markers. Interestingly, ex vivo and in vitro studies suggested that BU224 treatment increased the size of dendritic spines and induced a threefold reduction in amyloid-β (Aβ)-induced functional changes in NMDA receptors. CONCLUSION AND IMPLICATIONS Sub-chronic treatment with BU224 restores memory and reduces inflammation in transgenic AD mice, at stages when animals display severe pathology.
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Affiliation(s)
- Nazanin Mirzaei
- Department of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - Bibiana C Mota
- Department of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - Amy M Birch
- Department of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - Nicola Davis
- Department of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - Carmen Romero-Molina
- Department of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - Loukia Katsouri
- Department of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - Emily O C Palmer
- Department of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - Arantxa Golbano
- Institute of Neurosciences, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Laura J Riggall
- Department of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - Istvan Nagy
- Department of Surgery and Cancer, Imperial College London, Chelsea and Westminster Hospital, London, UK
| | - Robin Tyacke
- Department of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - David J Nutt
- Department of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - Magdalena Sastre
- Department of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
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7
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Rahangdale S, Fating R, Gajbhiye M, Kapse M, Inamdar N, Kotagale N, Umekar M, Taksande B. Involvement of agmatine in antidepressant-like effect of HMG-CoA reductase inhibitors in mice. Eur J Pharmacol 2020; 892:173739. [PMID: 33220274 DOI: 10.1016/j.ejphar.2020.173739] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/28/2020] [Accepted: 11/04/2020] [Indexed: 02/06/2023]
Abstract
3-Hydroxy-3-methyl-glutaryl-co-enzyme-A (HMG-CoA) reductase inhibitors (statins) are popularly used for the treatment of obesity and hypercholesterolemia with established safety profile. Statins exhibits a wide range of neurobehavioral effects in addition to their peripheral actions, and may be beneficial in treatment of psychiatric conditions. Present study investigated the role of agmatine and imidazoline receptors in antidepressant-like effect of statins in mouse forced swimming test (FST). The antidepressant-like effect of atorvastatin (5 mg/kg, p.o.) and simvastatin (10 mg/kg, p.o.) was potentiated by pretreatment with agmatine (5 mg/kg, i.p.) as well as the drugs known to increase endogenous agmatine levels in brain viz., L-arginine (40 μg/mouse, i.c.v.), an agmatine biosynthetic precursor; arcaine (50 μg/mouse, i.c.v), agmatinase inhibitor; and aminoguanidine (6.5 μg/mouse, i.c.v.), a diamine oxidase inhibitor. Further, both the statins increased agmatine levels within hippocampus and prefrontal cortex. Conversely, prior administration of I1 receptor antagonist, efaroxan (1 mg/kg, i.p.) and I2 receptor antagonist, idazoxan (0.25 mg/kg, i.p.) blocked the antidepressant-like effect of statins and their synergistic combination with agmatine. These results demonstrate the involvement of agmatine and imidazoline receptors in antidepressant-like effect of statins and suggest as a potential therapeutic target for the treatment of depressive disorders.
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Affiliation(s)
- Sandip Rahangdale
- Division of Neuroscience, Department of Pharmacology, Smt. Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur, M.S, 441 002, India
| | - Rajshree Fating
- Division of Neuroscience, Department of Pharmacology, Smt. Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur, M.S, 441 002, India
| | - Mona Gajbhiye
- Division of Neuroscience, Department of Pharmacology, Smt. Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur, M.S, 441 002, India
| | - Mona Kapse
- Division of Neuroscience, Department of Pharmacology, Smt. Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur, M.S, 441 002, India
| | - Nazma Inamdar
- Government College of Pharmacy, Kathora Naka, VMV Road, Amravati, M.S, 444604, India
| | - Nandkishor Kotagale
- Division of Neuroscience, Department of Pharmacology, Smt. Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur, M.S, 441 002, India; Government College of Pharmacy, Kathora Naka, VMV Road, Amravati, M.S, 444604, India
| | - Milind Umekar
- Division of Neuroscience, Department of Pharmacology, Smt. Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur, M.S, 441 002, India
| | - Brijesh Taksande
- Division of Neuroscience, Department of Pharmacology, Smt. Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur, M.S, 441 002, India.
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8
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Kotagale N, Dixit M, Garmelwar H, Bhondekar S, Umekar M, Taksande B. Agmatine reverses memory deficits induced by Aβ1–42 peptide in mice: A key role of imidazoline receptors. Pharmacol Biochem Behav 2020; 196:172976. [DOI: 10.1016/j.pbb.2020.172976] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/19/2020] [Accepted: 06/21/2020] [Indexed: 12/13/2022]
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9
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Hernández-Hernández E, García-Sevilla JA, García-Fuster MJ. Exploring the antidepressant-like potential of the selective I2-imidazoline receptor ligand LSL 60101 in adult male rats. Pharmacol Rep 2020; 73:288-295. [DOI: 10.1007/s43440-020-00148-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/06/2020] [Accepted: 07/24/2020] [Indexed: 12/11/2022]
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10
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Amelioration of BPSD-Like Phenotype and Cognitive Decline in SAMP8 Mice Model Accompanied by Molecular Changes after Treatment with I 2-Imidazoline Receptor Ligand MCR5. Pharmaceutics 2020; 12:pharmaceutics12050475. [PMID: 32456135 PMCID: PMC7285228 DOI: 10.3390/pharmaceutics12050475] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 05/19/2020] [Accepted: 05/22/2020] [Indexed: 12/21/2022] Open
Abstract
Behavioural and psychological symptoms of dementia (BPSD), including fear-anxiety- and depressive-like behaviour, are present in Alzheimer's disease (AD), together with memory decline. I2-imidazoline receptors (I2-IRs) have been associated with neuropsychiatric and neurodegenerative disorders, further, I2-IR ligands have demonstrated a neuroprotective role in the central nervous system (CNS). In this study, we assessed the effect of the I2-IR ligand MCR5 on both cognitive and non-cognitive symptoms in the Senescence accelerated mice prone 8 (SAMP8) mouse model. Oral administration of I2-IR ligand MCR5 (5 mg/kg/day for four weeks) in 10-month SAMP8 mice ameliorated both BPSD-like phenotype and cognitive decline by attenuating depressive-like behaviour, reducing fear-anxiety-like behaviour and improving cognitive performance using different tasks. Interaction of I2-IR ligand MCR5 with serotoninergic system did not account for behavioural or cognitive improvement, although changes in molecular pathways underlying depression and anxiety phenotype were observed. MCR5 increased levels of p-AKT, phosphorylated glycogen synthase kinase 3 β (GSK3β) at Ser9 and phosphorylated mammalian target of rapamycin complex 1 (mTORC1) levels in SAMP8 treated mice compared to SAMP8 control. Moreover, MCR5 treatment altered N-methyl-d-aspartate receptor (NMDA) 2B phosphorylation, and decreased the protein levels of phosphorylated cyclin-dependent kinase 5 (p-CDK5) and dopamine- and cyclic adenosine monophosphate (cAMP)-regulated phosphoprotein of Mr 32 kDa phosphorylated at Thr75 (p-DARPP32), with a parallel increase in protein kinase A (PKA) and p-cAMP response element-binding (pCREB) levels. Consistent with these changes MCR5 attenuated neuroinflammation by decreasing expression of pro-inflammatory markers such as Tumor necrosis factor-alpha (Tnf-α), Interleukin 1β (Il-1β), Interleukin 6 (Il-6), and promoted synaptic plasticity by increasing levels of postsynaptic density protein 95 (PSD95) as well as ameliorating tropomyosin-related kinase B (TrkB) and nerve growth factor receptor (NGFR) signalling. Collectively, these results increase the potential of highly selective I2-IR ligands as therapeutic agents in age-related BPSD and cognitive alterations.
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11
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Abás S, Rodríguez-Arévalo S, Bagán A, Griñán-Ferré C, Vasilopoulou F, Brocos-Mosquera I, Muguruza C, Pérez B, Molins E, Luque FJ, Pérez-Lozano P, de Jonghe S, Daelemans D, Naesens L, Brea J, Loza MI, Hernández-Hernández E, García-Sevilla JA, García-Fuster MJ, Radan M, Djikic T, Nikolic K, Pallàs M, Callado LF, Escolano C. Bicyclic α-Iminophosphonates as High Affinity Imidazoline I2 Receptor Ligands for Alzheimer’s Disease. J Med Chem 2020; 63:3610-3633. [DOI: 10.1021/acs.jmedchem.9b02080] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Sònia Abás
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Sergio Rodríguez-Arévalo
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Andrea Bagán
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Christian Griñán-Ferré
- Pharmacology Section, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institut de Neurociències, University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Foteini Vasilopoulou
- Pharmacology Section, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institut de Neurociències, University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Iria Brocos-Mosquera
- Department of Pharmacology, and Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, University of the Basque Country, UPV/EHU, E-48940 Leioa, Bizkaia, Spain
| | - Carolina Muguruza
- Department of Pharmacology, and Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, University of the Basque Country, UPV/EHU, E-48940 Leioa, Bizkaia, Spain
| | - Belén Pérez
- Department of Pharmacology, Therapeutic and Toxicology, Autonomous University of Barcelona, E-08193 Barcelona, Spain
| | - Elies Molins
- Institut de Ciència de Materials de Barcelona (CSIC), Campus UAB, E-08193 Cerdanyola, Spain
| | - F. Javier Luque
- Department of Nutrition, Food Sciences and Gastronomy, School of Pharmacy and Food Sciences, Institute of Biomedicine (IBUB), and Institute of Theoretical and Computational Chemistry (IQTCUB), University of Barcelona, E-08921 Santa Coloma de Gramanet, Spain
| | - Pilar Pérez-Lozano
- Unit of Pharmaceutical Technology, Pharmacy and Pharmaceutical Technology, and Physical Chemistry Department, Faculty of Pharmacy and Food Sciences, University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Steven de Jonghe
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
| | - Dirk Daelemans
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
| | - Lieve Naesens
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
| | - José Brea
- Innopharma screening platform, BioFarma research group, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - M. Isabel Loza
- Innopharma screening platform, BioFarma research group, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Elena Hernández-Hernández
- IUNICS University of the Balearic Islands (UIB), and Health Research Institute of the Balearic Islands (IdISBa), Cra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - Jesús A. García-Sevilla
- IUNICS University of the Balearic Islands (UIB), and Health Research Institute of the Balearic Islands (IdISBa), Cra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - M. Julia García-Fuster
- IUNICS University of the Balearic Islands (UIB), and Health Research Institute of the Balearic Islands (IdISBa), Cra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - Milica Radan
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11000 Belgrade, Serbia
| | - Teodora Djikic
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11000 Belgrade, Serbia
| | - Katarina Nikolic
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11000 Belgrade, Serbia
| | - Mercè Pallàs
- Pharmacology Section, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institut de Neurociències, University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Luis F. Callado
- Department of Pharmacology, and Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, University of the Basque Country, UPV/EHU, E-48940 Leioa, Bizkaia, Spain
| | - Carmen Escolano
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
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12
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Griñán-Ferré C, Vasilopoulou F, Abás S, Rodríguez-Arévalo S, Bagán A, Sureda FX, Pérez B, Callado LF, García-Sevilla JA, García-Fuster MJ, Escolano C, Pallàs M. Behavioral and Cognitive Improvement Induced by Novel Imidazoline I 2 Receptor Ligands in Female SAMP8 Mice. Neurotherapeutics 2019; 16:416-431. [PMID: 30460457 PMCID: PMC6554384 DOI: 10.1007/s13311-018-00681-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
As populations increase their life expectancy, age-related neurodegenerative disorders such as Alzheimer's disease have become more common. I2-Imidazoline receptors (I2-IR) are widely distributed in the central nervous system, and dysregulation of I2-IR in patients with neurodegenerative diseases has been reported, suggesting their implication in cognitive impairment. This evidence indicates that high-affinity selective I2-IR ligands potentially contribute to the delay of neurodegeneration. In vivo studies in the female senescence accelerated mouse-prone 8 mice have shown that treatment with I2-IR ligands, MCR5 and MCR9, produce beneficial effects in behavior and cognition. Changes in molecular pathways implicated in oxidative stress, inflammation, synaptic plasticity, and apoptotic cell death were also studied. Furthermore, treatments with these I2-IR ligands diminished the amyloid precursor protein processing pathway and increased Aβ degrading enzymes in the hippocampus of SAMP8 mice. These results collectively demonstrate the neuroprotective role of these new I2-IR ligands in a mouse model of brain aging through specific pathways and suggest their potential as therapeutic agents in brain disorders and age-related neurodegenerative diseases.
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Affiliation(s)
- Christian Griñán-Ferré
- Pharmacology Section, Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institut de Neurociències, University of Barcelona, Av. Joan XXIII, 27-31, 08028, Barcelona, Spain
| | - Foteini Vasilopoulou
- Pharmacology Section, Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institut de Neurociències, University of Barcelona, Av. Joan XXIII, 27-31, 08028, Barcelona, Spain
| | - Sònia Abás
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Joan XXIII, 27-31, 08028, Barcelona, Spain
| | - Sergio Rodríguez-Arévalo
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Joan XXIII, 27-31, 08028, Barcelona, Spain
| | - Andrea Bagán
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Joan XXIII, 27-31, 08028, Barcelona, Spain
| | - Francesc X Sureda
- Pharmacology Unit, Faculty of Medicine and Health Sciences, University of Rovira and Virgili, C./St. Llorenç 21, 43201, Reus, Tarragona, Spain
| | - Belén Pérez
- Departament of Pharmacology, Therapeutic and Toxicology, Autonomous University of Barcelona, 08193, Barcelona, Spain
| | - Luis F Callado
- Department of Pharmacology, University of the Basque Country, UPV/EHU, 48940, Leioa, Bizkaia, Spain
- Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Leioa, Spain
| | - Jesús A García-Sevilla
- Laboratory of Neuropharmacology, IUNICS and IdISBa, University of the Balearic Islands (UIB), Cra. Valldemossa km 7.5, 07122, Palma de Mallorca, Spain
| | - M Julia García-Fuster
- Laboratory of Neuropharmacology, IUNICS and IdISBa, University of the Balearic Islands (UIB), Cra. Valldemossa km 7.5, 07122, Palma de Mallorca, Spain
| | - Carmen Escolano
- Laboratory of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Av. Joan XXIII, 27-31, 08028, Barcelona, Spain
| | - Mercè Pallàs
- Pharmacology Section, Department of Pharmacology, Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences, and Institut de Neurociències, University of Barcelona, Av. Joan XXIII, 27-31, 08028, Barcelona, Spain.
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13
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Tyacke RJ, Myers JFM, Venkataraman A, Mick I, Turton S, Passchier J, Husbands SM, Rabiner EA, Gunn RN, Murphy PS, Parker CA, Nutt DJ. Evaluation of 11C-BU99008, a PET Ligand for the Imidazoline 2 Binding Site in Human Brain. J Nucl Med 2018; 59:1597-1602. [PMID: 29523627 DOI: 10.2967/jnumed.118.208009] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 02/21/2018] [Indexed: 11/16/2022] Open
Abstract
The imidazoline2 binding site (I2BS) is thought to be expressed in glia and implicated in the regulation of glial fibrillary acidic protein. A PET ligand for this target would be important for the investigation of neurodegenerative and neuroinflammatory diseases. 11C-BU99008 has previously been identified as a putative PET radioligand. Here, we present the first in vivo characterization of this PET radioligand in humans and assess its test-retest reproducibility. Methods: Fourteen healthy male volunteers underwent dynamic PET imaging with 11C-BU99008 and arterial sampling. Six subjects were used in a test-retest assessment, and 8 were used in a pharmacologic evaluation, undergoing a second or third heterologous competition scan with the mixed I2BS/α2-adrenoceptor drug idazoxan (n = 8; 20, 40, 60, and 80 mg) and the mixed irreversible monoamine oxidase type A/B inhibitor isocarboxazid (n = 4; 50 mg). Regional time-activity data were generated from arterial plasma input functions corrected for metabolites using the most appropriate model to derive the outcome measure VT (regional distribution volume). All image processing and kinetic analyses were performed in MIAKAT. Results: Brain uptake of 11C-BU99008 was good, with reversible kinetics and a heterogeneous distribution consistent with known I2BS expression. Model selection criteria indicated that the 2-tissue-compartment model was preferred. VT estimates were high in the striatum (105 ± 21 mL⋅cm-3), medium in the cingulate cortex (62 ± 10 mL⋅cm-3), and low in the cerebellum (41 ± 7 mL⋅cm-3). Test-retest reliability was reasonable. The uptake was dose-dependently reduced throughout the brain by pretreatment with idazoxan, with an average block across all regions of about 60% (VT, ∼30 mL⋅cm-3) at the highest dose (80 mg). The median effective dose for idazoxan was 28 mg. Uptake was not blocked by pretreatment with the monoamine oxidase inhibitor isocarboxazid. Conclusion:11C-BU99008 in human PET studies demonstrates good brain delivery, reversible kinetics, heterogeneous distribution, specific binding signal consistent with I2BS distribution, and good test-retest reliability.
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Affiliation(s)
- Robin J Tyacke
- Neuropsychopharmacology Unit, Centre for Academic Psychiatry, Division of Brain Sciences, Imperial College London, London, United Kingdom
| | - Jim F M Myers
- Neuropsychopharmacology Unit, Centre for Academic Psychiatry, Division of Brain Sciences, Imperial College London, London, United Kingdom
| | - Ashwin Venkataraman
- Neuropsychopharmacology Unit, Centre for Academic Psychiatry, Division of Brain Sciences, Imperial College London, London, United Kingdom
| | - Inge Mick
- Neuropsychopharmacology Unit, Centre for Academic Psychiatry, Division of Brain Sciences, Imperial College London, London, United Kingdom
| | - Samuel Turton
- Neuropsychopharmacology Unit, Centre for Academic Psychiatry, Division of Brain Sciences, Imperial College London, London, United Kingdom
| | - Jan Passchier
- Imanova Limited, Imperial College London, London, United Kingdom
| | - Stephen M Husbands
- Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
| | | | - Roger N Gunn
- Imanova Limited, Imperial College London, London, United Kingdom
- Restorative Neurosciences, Imperial College London, London, United Kingdom; and
| | - Philip S Murphy
- Experimental Medicine Imaging, GlaxoSmithKline Research and Development Limited, Stevenage, United Kingdom
| | - Christine A Parker
- Neuropsychopharmacology Unit, Centre for Academic Psychiatry, Division of Brain Sciences, Imperial College London, London, United Kingdom
- Experimental Medicine Imaging, GlaxoSmithKline Research and Development Limited, Stevenage, United Kingdom
| | - David J Nutt
- Neuropsychopharmacology Unit, Centre for Academic Psychiatry, Division of Brain Sciences, Imperial College London, London, United Kingdom
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14
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Agmatine: multifunctional arginine metabolite and magic bullet in clinical neuroscience? Biochem J 2017; 474:2619-2640. [DOI: 10.1042/bcj20170007] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 05/23/2017] [Accepted: 05/25/2017] [Indexed: 12/12/2022]
Abstract
Agmatine, the decarboxylation product of arginine, was largely neglected as an important player in mammalian metabolism until the mid-1990s, when it was re-discovered as an endogenous ligand of imidazoline and α2-adrenergic receptors. Since then, a wide variety of agmatine-mediated effects have been observed, and consequently agmatine has moved from a wallflower existence into the limelight of clinical neuroscience research. Despite this quantum jump in scientific interest, the understanding of the anabolism and catabolism of this amine is still vague. The purification and biochemical characterization of natural mammalian arginine decarboxylase and agmatinase still are open issues. Nevertheless, the agmatinergic system is currently one of the most promising candidates in order to pharmacologically interfere with some major diseases of the central nervous system, which are summarized in the present review. Particularly with respect to major depression, agmatine, its derivatives, and metabolizing enzymes show great promise for the development of an improved treatment of this common disease.
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15
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Abás S, Erdozain AM, Keller B, Rodríguez-Arévalo S, Callado LF, García-Sevilla JA, Escolano C. Neuroprotective Effects of a Structurally New Family of High Affinity Imidazoline I 2 Receptor Ligands. ACS Chem Neurosci 2017; 8:737-742. [PMID: 28029766 DOI: 10.1021/acschemneuro.6b00426] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The imidazoline I2 receptors (I2-IRs) are widely distributed in the brain, and I2-IR ligands may have therapeutic potential as neuroprotective agents. Since structural data for I2-IR remains unknown, the discovery of selective I2-IR ligands devoid of α2-adrenoceptor (α2-AR) affinity is likely to provide valuable tools in defining the pharmacological characterization of these receptors. We report the pharmacological characterization of a new family of (2-imidazolin-4-yl)phosphonates. Radioligand binding studies showed that they displayed a higher affinity for I2-IRs than idazoxan, and high I2/α2 selectivity. In vivo studies in mice showed that acute treatments with 1b and 2c significantly increased p-FADD/FADD ratio (an index of cell survival) in the hippocampus when compared with vehicle-treated controls. Additionally, acute and repeated treatments with 2c, but not with 1b, markedly reduced hippocampal p35 cleavage into neurotoxic p25. The present results indicate a neuroprotective potential of (2-imidazolin-4-yl)phosphonates acting at I2-IRs.
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Affiliation(s)
- Sònia Abás
- Laboratory
of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology,
Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences,
and Institute of Biomedicine (IBUB), University of Barcelona, Av. Joan XXIII 27-31, E-08028 Barcelona, Spain
| | - Amaia M. Erdozain
- Department
of Pharmacology, University of the Basque Country, UPV/EHU, E-48940 Leioa, Bizkaia, Spain
- Centro
de Investigación Biomédica en Red de Salud Mental, CIBERSAM
| | - Benjamin Keller
- Laboratory
of Neuropharmacology, IUNICS/IdISPa, University of the Balearic Islands (UIB), Cra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - Sergio Rodríguez-Arévalo
- Laboratory
of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology,
Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences,
and Institute of Biomedicine (IBUB), University of Barcelona, Av. Joan XXIII 27-31, E-08028 Barcelona, Spain
| | - Luis F. Callado
- Department
of Pharmacology, University of the Basque Country, UPV/EHU, E-48940 Leioa, Bizkaia, Spain
- Centro
de Investigación Biomédica en Red de Salud Mental, CIBERSAM
| | - Jesús A. García-Sevilla
- Laboratory
of Neuropharmacology, IUNICS/IdISPa, University of the Balearic Islands (UIB), Cra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - Carmen Escolano
- Laboratory
of Medicinal Chemistry (Associated Unit to CSIC), Department of Pharmacology,
Toxicology and Medicinal Chemistry, Faculty of Pharmacy and Food Sciences,
and Institute of Biomedicine (IBUB), University of Barcelona, Av. Joan XXIII 27-31, E-08028 Barcelona, Spain
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16
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Keller B, García-Sevilla JA. Dysregulation of IRAS/nischarin and other potential I 1-imidazoline receptors in major depression postmortem brain: Downregulation of basal contents by antidepressant drug treatments. J Affect Disord 2017; 208:646-652. [PMID: 27836117 DOI: 10.1016/j.jad.2016.10.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 09/28/2016] [Accepted: 10/16/2016] [Indexed: 11/16/2022]
Abstract
BACKGROUND Major depressive disorder (MDD) has been associated with altered brain densities of imidazoline receptors (I1-IR and I2-IR types). METHODS The contents of potential I1-IR IRAS/nischarin (167kDa) and, for comparison, those of I1- (85kDa) and I2- (45kDa and 30kDa) IR proteins were quantified by western blotting in postmortem prefrontal cortex (PFC/BA9) of antidepressant-free ([MDD(-)], n=9) and antidepressant-treated ([MDD(+)], n=12) subjects and matched controls (n=19). RESULTS In MDD, regardless of antidepressant treatment (n=21), IRAS/nischarin was not altered in PFC/BA9. However, the content of IRAS/nischarin was found modestly and not significantly increased (+19%, p=0.075) in MDD(-) and significantly decreased (-24%, p=0.001) in MDD(+), revealing that basal I1-IR content was downregulated by antidepressants. Putative 85kDa I1-IR was upregulated (+35%, p=0.035) in MDD(-) but it was not reduced (-14%, p=0.37) in MDD(+). There was a positive correlation (r=0.33, p=0.037, n=40) between the contents of IRAS/nischarin and 85kDa IR proteins in PFC/BA9 (control and MDD subjects). In MDD and regardless of antidepressants, the content of cortical 45kDa I2-IR was increased (+31%, p=0.006) and that of 30kDa I2-IR decreased (-14%, p=0.002), indicating basal dysregulations of these potential IRs. LIMITATIONS MDD(+) subjects had been treated with a variety of antidepressant drugs. The results must be understood in the context of suicide victims with MDD. CONCLUSIONS The dysregulation of IRAS/nischarin in depressed brains is a major novel finding that supports a role of this potential I1-IR in the neurobiology of MDD and in the molecular mechanisms of antidepressant drugs.
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Affiliation(s)
- Benjamin Keller
- Laboratori de Neurofarmacologia, IUNICS/IdISPa, Universitat de les Illes Balears (UIB), Palma de Mallorca, Spain; Redes Temáticas de Investigación Cooperativa en Salud-Red de Trastornos Adictivos (RETICS-RTA), ISCIII, Madrid, Spain
| | - Jesús A García-Sevilla
- Laboratori de Neurofarmacologia, IUNICS/IdISPa, Universitat de les Illes Balears (UIB), Palma de Mallorca, Spain; Redes Temáticas de Investigación Cooperativa en Salud-Red de Trastornos Adictivos (RETICS-RTA), ISCIII, Madrid, Spain.
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17
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Kawamura K, Shimoda Y, Yui J, Zhang Y, Yamasaki T, Wakizaka H, Hatori A, Xie L, Kumata K, Fujinaga M, Ogawa M, Kurihara Y, Nengaki N, Zhang MR. A useful PET probe [ 11C]BU99008 with ultra-high specific radioactivity for small animal PET imaging of I 2-imidazoline receptors in the hypothalamus. Nucl Med Biol 2016; 45:1-7. [PMID: 27835825 DOI: 10.1016/j.nucmedbio.2016.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 10/14/2016] [Accepted: 10/24/2016] [Indexed: 01/23/2023]
Abstract
INTRODUCTION A positron emission tomography (PET) probe with ultra-high specific radioactivity (SA) enables measuring high receptor specific binding in brain regions by avoiding mass effect of the PET probe itself. It has been reported that PET probe with ultra-high SA can detect small change caused by endogenous or exogenous ligand. Recently, Kealey et al. developed [11C]BU99008, a more potent PET probe for I2-imidazoline receptors (I2Rs) imaging, with a conventional SA (mean 76GBq/μmol) showed higher specific binding in the brain. Here, to detect small change of specific binding for I2Rs caused by endogenous or exogenous ligand in an extremely small region, such as hypothalamus in the brain, we synthesized and evaluated [11C]BU99008 with ultra-high SA as a useful PET probe for small-animal PET imaging of I2Rs. METHODS [11C]BU99008 was prepared by [11C]methylation of N-desmethyl precursor with [11C]methyl iodide. Biodistribution, metabolite analysis, and brain PET studies were conducted in rats. RESULTS [11C]BU99008 with ultra-high SA in the range of 5400-16,600GBq/μmol were successfully synthesized (n=7), and had appropriate radioactivity for in vivo study. In the biodistribution study, the mean radioactivity levels in all investigated tissues except for the kidney did not show significant difference between [11C]BU99008 with ultra-high SA and that with conventional SA. In the metabolite analysis, the percentage of unchanged [11C]BU99008 at 30min after the injection of probes with ultra-high and conventional SA was similar in rat brain and plasma. In the PET study of rats' brain, radioactivity level (AUC30-60 min) in the hypothalamus of rats injected with [11C]BU99008 with ultra-high SA (64 [SUV ∙ min]) was significantly higher than that observed for that with conventional SA (50 [SUV ∙ min]). The specific binding of [11C]BU99008 with ultra-high SA (86% of total binding) for I2R was higher than that of conventional SA (76% of total binding). CONCLUSION A PET study using [11C]BU99008 with ultra-high SA would thus contribute to the detection of small changes in or small regions with I2R expression and hence may be useful in elucidating new functions of I2R.
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Affiliation(s)
- Kazunori Kawamura
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan.
| | - Yoko Shimoda
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Joji Yui
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Yiding Zhang
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Tomoteru Yamasaki
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Hidekatsu Wakizaka
- Department of Medical Physics, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Akiko Hatori
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Lin Xie
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Katsushi Kumata
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Masayuki Fujinaga
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Masanao Ogawa
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan; SHI Accelerator Service Ltd., Tokyo 141-0032, Japan
| | - Yusuke Kurihara
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan; SHI Accelerator Service Ltd., Tokyo 141-0032, Japan
| | - Nobuki Nengaki
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan; SHI Accelerator Service Ltd., Tokyo 141-0032, Japan
| | - Ming-Rong Zhang
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
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18
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Keller B, García-Sevilla JA. Immunodetection and subcellular distribution of imidazoline receptor proteins with three antibodies in mouse and human brains: Effects of treatments with I1- and I2-imidazoline drugs. J Psychopharmacol 2015; 29:996-1012. [PMID: 26038110 DOI: 10.1177/0269881115586936] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Various imidazoline receptor (IR) proteins have been proposed to mediate the effects of selective I1- and I2-IR drugs. However, the association of these IR-binding proteins with classic I1- and I2-radioligand binding sites remains somewhat controversial. In this study, three IR antibodies (anti-NISCH and anti-nischarin for I1-IRs; and anti-IRBP for I1/I2-IRs) were used to immunodetect, characterize and compare IR protein patterns in brain (mouse and human; total homogenate, subcellular fractionation, grey and white matter) and some cell systems (neurones, astrocytes, human platelets). Various immunoreactive IRs (specific molecular weight bands coincidently detected with the different antibodies) were related to I1-IR (167 kDa, 105/115 kDa and 85 kDa proteins) or I2-IR (66 kDa, 45 kDa and 30 kDa proteins) types. The biochemical characterization of cortical 167 kDa protein, localized in the membrane/cytosol but not in the nucleus, indicated that this I1-IR also forms part of higher order nischarin-related complexes. The contents of I1-IR (167 kDa, 105/115 kDa, and 85 kDa) proteins in mouse brain cortex were upregulated by treatment with I1-drugs (moxonidine, efaroxan) but not with I2-drugs (BU-224, LSL 61122). Conversely, the contents of I2-IR (66 kDa, 45 kDa and 30 kDa) proteins in mouse brain cortex were modulated by treatment with I2-drugs (decreases after BU-224 and LSL 61122, and increases after idazoxan) but not with I1-drugs (with the exception of moxonidine). These findings further indicate that brain immunoreactive IR proteins exist in multiple forms that can be grouped in the already known I1- and I2-IR types, which are expressed both in neurones and astrocytes.
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Affiliation(s)
- Benjamin Keller
- Laboratori de Neurofarmacologia, IUNICS-IdISPa, Universitat de les Illes Balears, Palma de Mallorca, Spain and Redes Temáticas de Investigación Cooperativa en Salud-Red de Trastornos Adictivos (RETICS-RTA), ISCIII, Madrid, Spain
| | - Jesús A García-Sevilla
- Laboratori de Neurofarmacologia, IUNICS-IdISPa, Universitat de les Illes Balears, Palma de Mallorca, Spain and Redes Temáticas de Investigación Cooperativa en Salud-Red de Trastornos Adictivos (RETICS-RTA), ISCIII, Madrid, Spain
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19
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In vivo evaluation of a new 18F-labeled PET ligand, [18F]FEBU, for the imaging of I2-imidazoline receptors. Nucl Med Biol 2015; 42:406-12. [DOI: 10.1016/j.nucmedbio.2014.12.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 12/01/2014] [Accepted: 12/19/2014] [Indexed: 11/20/2022]
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20
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Kotagale NR, Tripathi SJ, Aglawe MM, Chopde CT, Umekar MJ, Taksande BG. Evidences for the agmatine involvement in antidepressant like effect of bupropion in mouse forced swim test. Pharmacol Biochem Behav 2013; 107:42-7. [PMID: 23583442 DOI: 10.1016/j.pbb.2013.03.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2012] [Revised: 03/25/2013] [Accepted: 03/30/2013] [Indexed: 11/19/2022]
Abstract
Although bupropion has been widely used in the treatment of depression, the precise mechanism of its therapeutic actions is not fully understood. The present study investigated the role of agmatine in an antidepressant like effect of bupropion in mouse forced swim test. The antidepressant like effect of bupropion was potentiated by pretreatment with agmatine (10-20mg/kg, ip) and by the drugs known to increase endogenous agmatine levels in brain viz., l-arginine (40 μg/mouse, icv), an agmatine biosynthetic precursor, ornithine decarboxylase inhibitor, dl-α-difluoromethyl ornithine hydrochloride, DFMO (12.5 μg/mouse, icv), diamine oxidase inhibitor, aminoguanidine (6.5 μg/mouse, icv) and agmatinase inhibitor, arcaine (50 μg/mouse, icv) as well as imidazoline I1 receptor agonists, moxonidine (0.25mg/kg, ip) and clonidine (0.015 mg/kg, ip) and imidazoline I2 receptor agonist, 2-(2-benzofuranyl)-2-imidazoline hydrochloride, 2-BFI (5mg/kg, ip). Conversely, prior administration of I1 receptor antagonist, efaroxan (1mg/kg, ip) and I2 receptor antagonist, idazoxan (0.25mg/kg, ip) blocked the antidepressant like effect of bupropion and its synergistic combination with agmatine. These results demonstrate involvement of agmatine in the antidepressant like effect of bupropion and suggest agmatine and imidazoline receptors as a potential therapeutic target for the treatment of depressive disorders.
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Affiliation(s)
- Nandkishor R Kotagale
- Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur, Maharashtra 441 002, India
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Tonello R, Villarinho JG, da Silva Sant'Anna G, Tamiozzo L, Machado P, Trevisan G, Pinto Martins MA, Ferreira J, Rubin MA. The potential antidepressant-like effect of imidazoline I2 ligand 2-BFI in mice. Prog Neuropsychopharmacol Biol Psychiatry 2012; 37:15-21. [PMID: 22122878 DOI: 10.1016/j.pnpbp.2011.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 10/31/2011] [Accepted: 11/14/2011] [Indexed: 12/17/2022]
Abstract
The compound 2-(2-benzofuranyl)-2-imidazoline (2-BFI) is a 2-imidazoline derivative that selectively inhibits the in vitro activity of monoamine oxidase-A and it is also an imidazoline I(2) agonist. However, the antidepressant potential of this compound and its mechanism of action have not been well defined. Therefore, in this study we investigated the antidepressant-like effect of 2-BFI in mice. 2-BFI (100 and 300μmol/kg, s.c.) significantly reduced the immobility time on the tail suspension test (TST) without changing locomotion in the open field test. The reduced the immobility time of 2-BFI (100μmol/kg, s.c.) was confirmed with the forced swimming test (FST). The antidepressant-like effect of 2-BFI (100μmol/kg, s.c.) in the TST was prevented by pretreatment with idazoxan (0.4μmol/kg, i.p., a I(2) site antagonist), methysergide (4μmol/kg, i.p., a non-selective serotonergic receptor antagonist) and haloperidol (0.1μmol/kg, i.p., a non-selective dopaminergic receptor antagonist). The anxiolytic effect of 2-BFI was also evaluated, using the elevated plus-maze test. 2-BFI (300μmol/kg, s.c.) was able to significantly increase the % of number of entries and the % of time spent in the open arms, indicating that it possesses an anxiolytic effect at high doses. In conclusion, these results suggest that the antidepressant-like effect of 2-BFI might involve serotonergic, dopaminergic and imidazoline systems, and then the imidazoline site could represent a new pharmacological target for the treatment of depression.
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Affiliation(s)
- Raquel Tonello
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil
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22
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Molderings GJ, Haenisch B. Agmatine (decarboxylated l-arginine): Physiological role and therapeutic potential. Pharmacol Ther 2012; 133:351-65. [DOI: 10.1016/j.pharmthera.2011.12.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 12/05/2011] [Indexed: 01/14/2023]
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Tyacke RJ, Fisher A, Robinson ESJ, Grundt P, Turner EM, Husbands SM, Hudson AL, Parker CA, Nutt DJ. Evaluation and initial in vitro and ex vivo characterization of the potential positron emission tomography ligand, BU99008 (2-(4,5-dihydro-1H-imidazol-2-yl)-1- methyl-1H-indole), for the imidazoline₂ binding site. Synapse 2012; 66:542-51. [PMID: 22290740 DOI: 10.1002/syn.21541] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 01/12/2012] [Accepted: 01/23/2012] [Indexed: 11/06/2022]
Abstract
The density of the Imidazoline₂ binding site (I₂BS) has been shown to change in psychiatric conditions such as depression and addiction, along with neurodegenerative disorders such as Alzheimer's disease and Huntington's chorea. The presence of I₂BS on glial cells and the possibility that they may in some way regulate glial fibrillary acidic protein has led to increased interest into the role of I₂BS and I₂BS ligands in conditions characterized by marked gliosis. In addition, it has been suggested that I₂BS may be a marker for human glioblastomas. Therefore, the development of a positron emission tomography (PET) radioligand for the I₂BS would be of major benefit in our understanding of these conditions. We now report the successful synthesis and initial pharmacological evaluation of potential PET radioligands for the I₂BS as well as the tritiation and characterization of the most favorable of the series, BU99008 (6), both in vitro and ex vivo in rat. The series as a whole demonstrated excellent affinity and selectivity for the I₂BS, with BU99008 (6) selected as the lead candidate to be taken forward for in vivo assessment. BU99008 (6) showed very good affinity for the I₂BS (K(i) of 1.4 nM; K(d) = 1.3 nM), good selectivity compared with the α₂ -adrenoceptor (909-fold). In addition, following peripheral administration, [³H]BU99008 demonstrated a heterogenous uptake into the rat brain consistent with the known distribution of the I₂BS in vivo. This, and the amenability of BU99008 (6) to radiolabeling with a positron-emitting radioisotope, indicates its potential as a PET radioligand for imaging the I₂BS in vivo.
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Affiliation(s)
- Robin J Tyacke
- Neuropsychopharmacology Unit, Centre for Pharmacology and Therapeutics, Hammersmith Hospital Campus, Imperial College London, London W12 0NN, United Kingdom.
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Kawamura K, Kimura Y, Yui J, Wakizaka H, Yamasaki T, Hatori A, Kumata K, Fujinaga M, Yoshida Y, Ogawa M, Nengaki N, Fukumura T, Zhang MR. PET study using [11C]FTIMD with ultra-high specific activity to evaluate I2-imidazoline receptors binding in rat brains. Nucl Med Biol 2012; 39:199-206. [DOI: 10.1016/j.nucmedbio.2011.07.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 06/29/2011] [Accepted: 07/26/2011] [Indexed: 10/17/2022]
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25
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Synthesis and evaluation of PET probes for the imaging of I2 imidazoline receptors in peripheral tissues. Nucl Med Biol 2012; 39:89-99. [DOI: 10.1016/j.nucmedbio.2011.06.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 06/02/2011] [Accepted: 06/07/2011] [Indexed: 11/21/2022]
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26
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Bernstein HG, Stich C, Jäger K, Dobrowolny H, Wick M, Steiner J, Veh R, Bogerts B, Laube G. Agmatinase, an inactivator of the putative endogenous antidepressant agmatine, is strongly upregulated in hippocampal interneurons of subjects with mood disorders. Neuropharmacology 2011; 62:237-46. [PMID: 21803059 DOI: 10.1016/j.neuropharm.2011.07.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 06/28/2011] [Accepted: 07/12/2011] [Indexed: 12/20/2022]
Abstract
The diamine agmatine may serve as a precursor in polyamine synthesis. In addition, agmatine may also act as a neurotransmitter, binding to imidazoline receptors. Behaviorally, agmatine exerts antidepressant-like effects. The enzyme agmatinase degrades agmatine. The gene coding for human agmatinase is located on chromosome 1p36, a gene locus which has been linked to bipolar disorder and major depression, but the enzyme has not yet been studied in the context of neuropsychiatric diseases. We analyzed agmatinase protein expression in postmortem hippocampi of individuals with affective disorders. Data from eleven patients with mood disorders (unipolar and bipolar depression) and twelve matched control cases were compared by immunocytochemical and morphometrical analysis. Agmatinase protein was detected in a subset of hippocampal interneurons. The protein was localized to perikarya, neurites and putative nerve endings contacting hippocampal pyramidal neurons and dentate gyrus granule cells. The number and the numerical density of agmatinase-immunopositive cell bodies were strongly elevated in depressive patients. In addition, a significantly increased density of agmatinase-immunoreactive punctate profiles was observed in the CA(4) region in unipolar and bipolar depression. The reported increased expression of agmatinase suggests a functional relevance of the enzyme in the pathophysiology of human affective disorders. This article is part of a Special Issue entitled 'Anxiety and Depression'.
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Affiliation(s)
- Hans-Gert Bernstein
- Department of Psychiatry, University of Magdeburg, Leipziger Str. 44, D-39120 Magdeburg, Germany.
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Ferrari F, Fiorentino S, Mennuni L, Garofalo P, Letari O, Mandelli S, Giordani A, Lanza M, Caselli G. Analgesic efficacy of CR4056, a novel imidazoline-2 receptor ligand, in rat models of inflammatory and neuropathic pain. J Pain Res 2011; 4:111-25. [PMID: 21647215 PMCID: PMC3100226 DOI: 10.2147/jpr.s18353] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2011] [Indexed: 12/02/2022] Open
Abstract
Two decades of investigations have failed to unequivocally clarify the functions and the molecular nature of imidazoline-2 receptors (I2R). However, there is robust pharmacological evidence for the functional modulation of monoamino oxidase (MAO) and other important enzyme activities by I2 site ligands. Some compounds of this class proved to be active experimental tools in preventing both experimental pain and opioid tolerance and dependence. Unfortunately, even though these compounds bind with high potency to central I2 sites, they fail to represent a valid clinical opportunity due to their pharmacokinetic, selectivity or side-effects profile. This paper presents the preclinical profile of a novel I2 ligand (2-phenyl-6-(1H-imidazol-1yl) quinazoline; [CR4056]) that selectively inhibits the activity of human recombinant MAO-A in a concentration-dependent manner. A sub-chronic four day oral treatment of CR4056 increased norepinephrine (NE) tissue levels both in the rat cerebral cortex (63.1% ±4.2%; P < 0.05) and lumbar spinal cord (51.3% ± 6.7%; P < 0.05). In the complete Freund’s adjuvant (CFA) rat model of inflammatory pain, CR4056 was found to be orally active (ED50 = 5.8 mg/kg, by mouth [p.o.]). In the acute capsaicin model, CR4056 completely blocked mechanical hyperalgesia in the injured hind paw (ED50 = 4.1 mg/kg, p.o.; ED100 = 17.9 mg/kg, p.o.). This effect was dose-dependently antagonized by the non-selective imidazoline I2/α2 antagonist idazoxan. In rat models of neuropathic pain, oral administration of CR4056 significantly attenuated mechanical hyperalgesia and allodynia. In summary, the present study suggests a novel pharmacological opportunity for inflammatory and/or neuropathic pain treatment based on selective interaction with central imidazoline-2 receptors.
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Affiliation(s)
- Flora Ferrari
- Department of Pharmacology and Toxicology, S.p.A., Monza (MB), Italy
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Kawamura K, Maeda J, Hatori A, Okauchi T, Nagai Y, Higuchi M, Suhara T, Fukumura T, Zhang MR. In vivo and in vitro imaging of I2 imidazoline receptors in the monkey brain. Synapse 2011; 65:452-5. [DOI: 10.1002/syn.20897] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Semenova S, Markou A. The alpha2 adrenergic receptor antagonist idazoxan, but not the serotonin-2A receptor antagonist M100907, partially attenuated reward deficits associated with nicotine, but not amphetamine, withdrawal in rats. Eur Neuropsychopharmacol 2010; 20:731-46. [PMID: 20627663 PMCID: PMC3545706 DOI: 10.1016/j.euroneuro.2010.05.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 04/01/2010] [Accepted: 05/04/2010] [Indexed: 11/27/2022]
Abstract
Based on phenomenological similarities between anhedonia (reward deficits) associated with drug withdrawal and the negative symptoms of schizophrenia, we showed previously that the atypical antipsychotic clozapine attenuated reward deficits associated with psychostimulant withdrawal. Antagonism of alpha(2) adrenergic and 5-HT(2A) receptors may contribute to these effects of clozapine. We investigated here whether blockade of alpha(2) or 5-HT(2A) receptors by idazoxan and M100907, respectively, would reverse anhedonic aspects of psychostimulant withdrawal. Idazoxan treatment facilitated recovery from spontaneous nicotine, but not amphetamine, withdrawal by attenuating reward deficits and increase the number of somatic signs. Thus, alpha(2) adrenoceptor blockade may have beneficial effects against nicotine withdrawal and may be involved in the effects of clozapine previously observed. M100907 worsened the anhedonia associated with nicotine and amphetamine withdrawal, suggesting that monotherapy with M100907 may exacerbate the expression of the negative symptoms of schizophrenia or nicotine withdrawal symptoms in people, including schizophrenia patients, attempting to quit smoking.
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Affiliation(s)
- Svetlana Semenova
- Department of Psychiatry, School of Medicine, University of California San Diego, 9500 Gilman Drive, M/C 0603, La Jolla, CA 92093-0603, USA.
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Imaging of I2-imidazoline receptors by small-animal PET using 2-(3-fluoro-[4-11C]tolyl)-4,5-dihydro-1H-imidazole ([11C]FTIMD). Nucl Med Biol 2010; 37:625-35. [DOI: 10.1016/j.nucmedbio.2010.02.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 02/26/2010] [Accepted: 02/28/2010] [Indexed: 11/23/2022]
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Kimura A, Tyacke RJ, Robinson JJ, Husbands SM, Minchin MC, Nutt DJ, Hudson AL. Identification of an imidazoline binding protein: creatine kinase and an imidazoline-2 binding site. Brain Res 2009; 1279:21-8. [PMID: 19410564 PMCID: PMC2722693 DOI: 10.1016/j.brainres.2009.04.044] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2009] [Revised: 03/28/2009] [Accepted: 04/22/2009] [Indexed: 12/11/2022]
Abstract
Drugs that bind to imidazoline binding proteins have major physiological actions. To date, three subtypes of such proteins, I(1), I(2) and I(3), have been proposed, although characterisations of these binding proteins are lacking. I(2) binding sites are found throughout the brain, particularly dense in the arcuate nucleus of the hypothalamus. Selective I(2) ligands demonstrate antidepressant-like activity and the identity of the proteins that respond to such ligands remained unknown until now. Here we report the isolation of a approximately 45 kDa imidazoline binding protein from rabbit and rat brain using a high affinity ligand for the I(2) subtype, 2-BFI, to generate an affinity column. Following protein sequencing of the isolated approximately 45 kDa imidazoline binding protein, we identified it to be brain creatine kinase (B-CK). B-CK shows high binding capacity to selective I(2) ligands; [(3)H]-2-BFI (5 nM) specifically bound to B-CK (2330+/-815 fmol mg protein(-1)). We predicted an I(2) binding pocket near the active site of B-CK using molecular modelling. Furthermore, B-CK activity was inhibited by a selective I(2) irreversible ligand, where 20 microM BU99006 reduced the enzyme activity by 16%, confirming the interaction between B-CK and the I(2) ligand. In summary, we have identified B-CK to be the approximately 45 kDa imidazoline binding protein and we have demonstrated the existence of an I(2) binding site within this enzyme. The importance of B-CK in regulating neuronal activity and neurotransmitter release may well explain the various actions of I(2) ligands in brain and the alterations in densities of I(2) binding sites in psychiatric disorders.
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Key Words
- 2-bfi, 2-(2-benzofuranyl)2-imidazoline
- bu224, 2-(4,5-dihydroimidaz-2-yl)quinoline
- bu99006, 5-isothiocyanoato-2-benzofuranyl-2-imidazoline
- b-ck, brain creatine kinase
- ck, creatine kinase
- gold, genetic optimisation for ligand docking
- gr, glucose-responsive
- i2, imidazoline-2 subtype
- katp channel, atp sensitive potassium channel
- mao, monoamine oxidase
- moe, molecular operating environment
- imidazoline binding protein
- creatine kinase
- 2-bfi
- harmane and psychiatric disorders
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Affiliation(s)
- Atsuko Kimura
- Psychopharmacology Unit, University of Bristol, BS1 3NY, UK
| | | | - James J. Robinson
- Department of Pharmacy and Pharmacology, University of Bath, BA2 7AY, UK
| | | | | | - David J. Nutt
- Psychopharmacology Unit, University of Bristol, BS1 3NY, UK
| | - Alan L. Hudson
- Department of Pharmacology, 9-70 Medical Sciences Building, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
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Smith KL, Jessop DS, Finn DP. Modulation of stress by imidazoline binding sites: implications for psychiatric disorders. Stress 2009; 12:97-114. [PMID: 19006007 DOI: 10.1080/10253890802302908] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
In this review, we present evidence for the involvement of imidazoline binding sites (IBS) in modulating responses to stress, through central control of monoaminergic and hypothalamo-pituitary-adrenal (HPA) axis activity. Pharmacological and physiological evidence is presented for differential effects of different IBS subtypes on serotoninergic and catecholaminergic pathways involved in control of basal and stress-stimulated HPA axis activity. IBS ligands can modulate behavioural and neuroendocrine responses in animal models of stress, depression and anxiety, and a body of evidence exists for alterations in central IBS expression in psychiatric patients, which can be normalised partially or fully by treatment with antidepressants. Dysfunction in monoaminergic systems and the HPA axis under basal and stress-induced activation has been extensively reported in psychiatric illnesses. On the basis of the literature, we suggest a potential therapeutic role for selective IBS ligands in the treatment of depression and anxiety disorders.
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Affiliation(s)
- Karen L Smith
- Department of Pharmacology and Therapeutics, NCBES Neuroscience Cluster, National University of Ireland, Galway, Ireland
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33
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Barrot M, Rettori MC, Guardiola-Lemaître B, Jarry C, Le Moal M, Piazza PV. Interactions between imidazoline binding sites and dopamine levels in the rat nucleus accumbens. Eur J Neurosci 2008. [DOI: 10.1111/j.1460-9568.2000.01318.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Piletz J, Baker R, Halaris A. Platelet imidazoline receptors as state marker of depressive symptomatology. J Psychiatr Res 2008; 42:41-9. [PMID: 17166518 PMCID: PMC2358986 DOI: 10.1016/j.jpsychires.2006.10.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2006] [Revised: 10/26/2006] [Accepted: 10/26/2006] [Indexed: 11/21/2022]
Abstract
OBJECTIVE Previous studies have shown that imidazoline receptors (IR-1) are increased in platelets and frontal cortex of depressed patients, and this up-regulation is normalized (down-regulated) after antidepressant drug treatments. It has been hypothesized that IR-1 up-regulation during the depressive episode may be a state marker for depressive symptomatology. The goal of the present study was to address the state versus trait question. METHOD Twelve healthy subjects (six males and six females) met stringent inclusion and exclusion criteria for physical and mental health. They received desipramine for 6 weeks in order to simulate the length of time and dosing used previously to obtain an IR-1 down-regulation and a therapeutic response in depressed patients. Outcome and safety measures included clinical, psychological, and cardiovascular assessments obtained throughout the study. Plasma concentrations of desipramine were measured throughout the 6 weeks of treatment and again after 2 weeks following tapered discontinuation of desipramine. Platelet receptors were assessed by Western blotting and radioligand binding assays. RESULTS Healthy subjects taking desipramine experienced mild dysphoric effects but there were no adverse events. The binding of 8 nM p-[(125)I]clonidine to IR-1 and alpha(2)-adrenoceptors in healthy subjects did not change during desipramine treatment. The immunodensity of the 33 kDa band associated with IR-1 gradually increased to a maximum, by week-6, of 26% higher than baseline (p < 0.01 compared to baseline). Two weeks after desipramine discontinuation, there was a decline in alpha(2)-adrenoceptor binding and 33 kDa band's immunodensity (p = 0.04). CONCLUSIONS The findings support the hypothesis that platelet IR-1 binding sites are a marker of mood state rather than of antidepressant-induced pharmacological regulation. By comparison, platelet alpha(2)-adrenoceptors appear to be regulated by desipramine as a pharmacological effect independent of mood state.
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Affiliation(s)
- John Piletz
- Department of Psychiatry and Behavioral Neuroscience, Loyola University Medical Center, Maywood, IL 60153, United States
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Corcoran J, Rodriguez F, Rozas I, Meana JJ, Callado LF. On the search of new I2-IBS aliphatic ligands: Bis-guanidino carbonyl derivatives. Bioorg Med Chem Lett 2007; 17:6009-12. [PMID: 17826997 DOI: 10.1016/j.bmcl.2007.07.093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Revised: 07/12/2007] [Accepted: 07/15/2007] [Indexed: 11/20/2022]
Abstract
Continuing with our search of aliphatic dicationic derivatives as I2-IBS ligands and looking at Amiloride, a known ligand of I2-IBS, we have incorporated the guanidinocarbonyl moiety into our aliphatic compounds with the intention of improving the binding to I2-IBS. Thus, we present the different approaches to the preparation and pharmacological evaluation (in human brain tissue) as I2-IBS ligands of a new series of aliphatic derivatives incorporating the guanidinocarbonyl group and with different chain length (n= 8-12, and 14 methylene groups).
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Affiliation(s)
- Jonathan Corcoran
- Centre for Synthesis and Chemical Biology, School of Chemistry, Trinity College Dublin, Dublin 2, Ireland
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36
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Zeidan MP, Zomkowski ADE, Rosa AO, Rodrigues ALS, Gabilan NH. Evidence for imidazoline receptors involvement in the agmatine antidepressant-like effect in the forced swimming test. Eur J Pharmacol 2007; 565:125-31. [PMID: 17445795 DOI: 10.1016/j.ejphar.2007.03.027] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2005] [Revised: 03/05/2007] [Accepted: 03/06/2007] [Indexed: 11/23/2022]
Abstract
This study investigated the involvement of the imidazoline receptors in the antidepressant-like effect of agmatine in the forced swimming test. The antidepressant-like effects of agmatine (10 mg/kg, i.p.) in the forced swimming test was blocked by pretreatment of mice with efaroxan (1 mg/kg, i.p., an imidazoline I1/alpha2-adrenoceptor antagonist), idazoxan (0.06 mg/kg, i.p., an imidazoline I2/alpha2-adrenoceptor antagonist) and antazoline (5 mg/kg, i.p., a ligand with high affinity for the I2 receptor). A subeffective dose of agmatine (0.001 mg/kg, i.p.) produced a synergistic antidepressant-like effect with clonidine (0.06 mg/kg, i.p, an imidazoline I1/alpha2-adrenoceptor agonist), moxonidine (0.5 mg/kg, i.p., an imidazoline I1/alpha2-adrenoceptor agonist), antazoline (1 mg/kg, i.p.) and MK-801 (0.001 mg/kg, i.p., a non-competitive NMDA receptor antagonist), but not with efaroxan (1 mg/kg, i.p.) and idazoxan (0.06 mg/kg, i.p.). Pretreatment of mice with yohimbine (1 mg/kg, i.p., an alpha2-adrenoceptor antagonist) blocked the synergistic antidepressant-like effect of agmatine (0.001 mg/kg, i.p.) with clonidine (0.06 mg/kg, i.p). A subeffective dose of MK-801 (0.001 mg/kg, i.p.) produced a synergistic antidepressant-like effect with antazoline (5 mg/kg, i.p.), but not with efaroxan (1 mg/kg, i.p.) or idazoxan (0.06 mg/kg, i.p.). In conclusion, this study suggests that the anti-immobility effect of agmatine in the forced swimming test is dependent on its interaction with imidazoline I1 and I2 receptors.
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Affiliation(s)
- Mariana P Zeidan
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, Florianópolis, 88040-900, SC, Brazil
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Sun Z, Chang CH, Ernsberger P. Identification of IRAS/Nischarin as an I1-imidazoline receptor in PC12 rat pheochromocytoma cells. J Neurochem 2007; 101:99-108. [PMID: 17254010 DOI: 10.1111/j.1471-4159.2006.04413.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The I1-imidazoline receptor (I1R) is a proposed target for drug action relevant to blood pressure and glucose control. The imidazoline receptor antisera-selected (IRAS) gene, also known as Nischarin, has several characteristics of an I1R. To test the contribution of IRAS to I1R binding capacity and cell-signaling function, an antisense probe targeting the initiating codon of rat IRAS gene was evaluated in PC12 rat pheochromocytoma cells, a well-established model for I1R action. The density of I1R was significantly reduced by antisense compared with control transfection (Bmax = 400 +/- 16 vs. 691 +/- 29 fmol/mg protein), without significantly affecting binding affinity (Kd = 0.30 +/- 0.04 vs. 0.39 +/- 0.05 nmol/L). Thus, IRAS expression is necessary for high-affinity binding to I1R. Western blots with polyclonal anti-IRAS showed reduced IRAS expression in the major 85-kDa band relative to an actin reference, paralleling the reduction in binding site density. To determine whether reduced IRAS expression attenuated I1R cell signaling, PC12 cells transfected with antisense or sense oligo-DNA were treated with moxonidine, an I1R agonist, then cell lysates were analyzed by western blot. Dose-dependent activation of extracellular signal-regulated kinase was attenuated without affecting the potency of the agonist. In contrast, extracellular signal-regulated kinase activation by insulin was unchanged. The IRAS gene is likely to encode an I1R or a functional subunit.
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Affiliation(s)
- Zheng Sun
- Department of Nutrition, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106-4906, USA
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38
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Gurguis GN. Psychiatric Disorders. Platelets 2007. [DOI: 10.1016/b978-012369367-9/50806-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Saczewski F, Tabin P, Tyacke RJ, Maconie A, Saczewski J, Kornicka A, Nutt DJ, Hudson AL. 2-(4,5-Dihydroimidazol-2-yl)benzimidazoles as highly selective imidazoline I2/adrenergic α2 receptor ligands. Bioorg Med Chem 2006; 14:6679-85. [PMID: 16782348 DOI: 10.1016/j.bmc.2006.05.062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2006] [Revised: 05/19/2006] [Accepted: 05/31/2006] [Indexed: 11/25/2022]
Abstract
2-(4,5-Dihydroimidazol-2-yl)benzimidazoles have been identified as selective imidazoline I2/alpha2-adrenoceptor ligands. 4-Methyl (2) and 4-chloro (4) derivatives display I2 affinity at nanomolar concentration (Ki=4.4 and 17.7 nM, respectively) and high I2/alpha2 selectivity ratio=4226 and 5649, respectively. An evidence has been obtained that pKa value influences considerably the I2/alpha2-selectivity ratio of this class of imidazoline I2 receptor ligands.
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Affiliation(s)
- Francieszek Saczewski
- Department of Chemical Technology of Drugs, Medical University of Gdańsk, 80-416 Gdańsk, Poland.
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Chen MJ, Russo-Neustadt AA. Exercise activates the phosphatidylinositol 3-kinase pathway. ACTA ACUST UNITED AC 2005; 135:181-93. [PMID: 15857681 DOI: 10.1016/j.molbrainres.2004.12.001] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2004] [Revised: 12/07/2004] [Accepted: 12/13/2004] [Indexed: 11/17/2022]
Abstract
Physical exercise is known to enhance psychological well-being and coping capacity. Voluntary physical exercise in rats also robustly and rapidly up-regulates hippocampal brain-derived neurotrophic factor (BDNF) mRNA levels, which are potentiated following a regimen of chronic antidepressant treatment. Increased BDNF levels are associated with enhanced activity of cyclic AMP response element binding protein (CREB). So far, relatively little is known about the intracellular signaling mechanisms mediating this effect of exercise. We wished to explore the possibility that exercise and/or antidepressant treatment activate the hippocampal phosphatidylinositol-3 (PI-3) kinase pathway, which mediates cellular survival. In young male Sprague-Dawley rats, we examined the effects of 2 weeks of daily voluntary wheel-running activity and/or tranylcypromine (n = 7 per group) on the levels of the active forms of protein-dependent kinase-1 (PDK-1), PI-3 kinase, phospho-thr308-Akt, phospho-ser473-Akt, and phospho-glycogen synthase kinase-3beta (GSK3beta; inactive form), as well as BDNF, activated CREB, and the phospho-Trk receptor, in the rat hippocampus, and compared these with sedentary saline-treated controls. Immunoblotting analyses revealed that in exercising rats, there was a significant increase in PI-3 kinase expression (4.61 times that of controls, P = 0.0161) and phosphorylation of PDK-1 (2.73 times that of controls, P = 0.0454), thr308-Akt (2.857 times that of controls, P = 0.0082), CREB (60.27 times that of controls, P = 0.05), and Trk (35.3 times that of controls, P < 0.0001) in the hippocampi of exercising animals; BDNF was also increased (3.2 times that of controls), but this was not statistically significant. In rats receiving both exercise and tranylcypromine, BDNF (4.51 times that of controls, P = 0.0068) and PI-3 kinase (4.88 times that of controls, P = 0.0103), and the phospho- forms of Trk (13.67 times that of controls, P = 0.0278), thr308-Akt (3.644 times that of controls, P = 0.0004), GSK-3beta (2.93 times that of controls, P = 0.026), and CREB (88.97 times that of controls, P = 0.0053) were significantly increased. These results suggest that the exercise-induced expression of BDNF is associated with the increased expression of several key intermediates of the PI-3 kinase/Akt pathway, which is known for its role in enhancing neuronal survival.
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Affiliation(s)
- Michael J Chen
- Department of Biological Sciences, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA 90032, USA.
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Dardonville C, Rozas I. Imidazoline binding sites and their ligands: an overview of the different chemical structures. Med Res Rev 2004; 24:639-61. [PMID: 15224384 DOI: 10.1002/med.20007] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Since Bousquet et al. discovered the imidazoline binding sites (IBS) two decades ago, when they realized that the antihypertensive drug clonidine interacts not only with the alpha2-adrenenoceptors (alpha2-AR) but also with a distinct imidazoline preferring binding site, these receptors have been paid a great deal of attention. At least two subtypes, I1 and I2, have been characterised based on their binding affinity for different radioligands, but their structures still remain unknown. The pharmacological profile of these IBSs has been the objective of several and very thorough reviews. However, a medicinal chemistry overview of the different IBS ligands prepared to date has never been attempted. In this study, we attempt to compile all the different chemical structures reported to date as IBS ligands and classify them in function of their chemical structure and binding affinity for the different IBS subtypes. Thus, we comment on the different endogenous IBS ligands known as well as the drugs described to interact with the I1-IBS which have found application as antihypertensive drugs. Then, we review those compounds described in the literature to interact with the I2-IBS, classifying them by their chemical families (imidazolines, guanidines, 2-aminoimidazolines, beta-carbolines). Finally, some conclusions are drawn.
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42
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Escribá PV, Ozaita A, García-Sevilla JA. Increased mRNA expression of alpha2A-adrenoceptors, serotonin receptors and mu-opioid receptors in the brains of suicide victims. Neuropsychopharmacology 2004; 29:1512-21. [PMID: 15199368 DOI: 10.1038/sj.npp.1300459] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The development of new therapies for the treatment of psychiatric disorders requires an in-depth knowledge of the molecular bases underlying these pathologies, which remain largely unknown. Alterations in adrenoceptors, serotonin receptors, and other G protein-coupled receptors (GPCRs) have been associated with suicide and depression. However, to date, there is little information about mRNA expression of the GPCRs in the frontal cortex of suicide victims. Our goal was to study the expression in the brain of these receptors. For this purpose, we measured mRNA levels by RT-PCR. We found that the expressions of alpha2A-adrenoceptors, 5-HT1A, 5-HT2A serotonin receptors, and mu-opioid receptors were elevated in the post-mortem brains of these suicide victims with respect to matched controls. Moreover, in the case of alpha2A-adrenoceptors (the only for which these data were available), a significant correlation was observed between the level of mRNA and protein quantified in the brain of the same subjects, indicating that protein synthesis of this receptor was not influenced by post-translational regulatory mechanisms. In addition, the degree of adrenoceptor and 5-HT receptor expressions appeared to be correlated in the brains of suicide victims and control subjects. Alterations in the expression of adrenoceptors, serotonin, and opioid receptors indicate that these signaling proteins might be related to the etiopathology of suicidal and depressive behaviors. Alternatively, such changes may represent adaptive mechanisms to compensate for other as yet unknown alterations. The results also suggest that these receptors could share common regulatory mechanisms.
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MESH Headings
- Adult
- Aged
- Brain Chemistry/genetics
- Depressive Disorder/genetics
- Depressive Disorder/metabolism
- Female
- Gene Expression Regulation/physiology
- Humans
- Male
- Middle Aged
- Nerve Tissue Proteins/biosynthesis
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Receptors, Adrenergic, alpha-2/biosynthesis
- Receptors, Adrenergic, alpha-2/genetics
- Receptors, Opioid, mu/biosynthesis
- Receptors, Opioid, mu/genetics
- Receptors, Serotonin/biosynthesis
- Receptors, Serotonin/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Suicide
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Affiliation(s)
- Pablo V Escribá
- Laboratory of Neuropharmacology, Associated Unit of the Cajal Institute (CSIC), Department of Biology, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), University of the Balearic Islands, Palma de Mallorca, Spain. pablo.escriba.uib.es
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43
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Saczewski F, Hudson AL, Tyacke RJ, Nutt DJ, Man J, Tabin P, Saczewski J. 2-(4,5-Dihydro-1H-imidazol-2-yl)indazole (indazim) derivatives as selective I2 imidazoline receptor ligands. Eur J Pharm Sci 2003; 20:201-8. [PMID: 14550886 DOI: 10.1016/s0928-0987(03)00182-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of variously substituted 2-(4,5-dihydro-1H-imidazol-2-yl)indazoles 3a-j and 2-(4,5-dihydro-1H-imidazol-2-yl)-4,5,6,7-tetrahydroindazole 6 were prepared by the regiospecific heteroalkylation of corresponding indazoles 1a-k with 2-chloro-4,5-dihydroimidazole (2). Their affinity to imidazoline I(2) receptors and alpha(2)-adrenergic receptors was determined by radioligand binding assay carried out on P(2) membrane preparations obtained from rat whole brains. 4-Chloro-2-(4,5-dihydro-1H-imidazol-2-yl)indazole (3f, 4-Cl-indazim) showed a 3076-fold difference in affinity for the [(3)H]2BFI-labeled imidazoline I(2) receptors relative to the [(3)H]RX821001-labeled alpha(2)-adrenergic receptors. This highly selective compound should prove to be useful tool in further understanding the functions of the imidazoline I(2) receptors.
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Affiliation(s)
- F Saczewski
- Department of Chemical Technology of Drugs, Medical University of Gdańsk, Al Gen Hallera 107, 80-416 Gdańsk, Poland.
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Piletz JE, Ordway GA, Rajkowska G, Zhu H, Klimek V, Swilley S, Duncan BJ, May W, Halaris AE. Differential expression of alpha2-adrenoceptor vs. imidazoline binding sites in postmortem orbitofrontal cortex and amygdala of depressed subjects. J Psychiatr Res 2003; 37:399-409. [PMID: 12849932 DOI: 10.1016/s0022-3956(03)00046-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Clonidine is a well established antihypertensive agent that is also used effectively to treat a variety of psychiatric disorders. Clonidine is a prototypic imidazoline compound that acts as an alpha(2)-adrenergic agonist but possesses nearly equivalent affinity for non-adrenergic imidazoline binding sites (I-sites). Receptor autoradiography of [(3)H]-clonidine binding presented herein compares densities of alpha(2)-adrenoceptors and I-sites (under a noradrenergic-mask) in Brodmann's area 47 of the left orbitofrontal cortex (OFC) and in six amygdaloid nuclei of subjects with major depression (n=12) vs. controls with no psychiatric history (n=11). Postmortem diagnoses were made from psychiatric interviews with next-of-kin. [(3)H]-Clonidine binding to alpha(2)-adrenoceptors in each of six OFC layers was lower, although not reaching statistical significance in any one layer by multivariate analysis, in depressives vs. control subjects. Binding to I-sites was conversely higher in depressives compared to control OFC layers, but did not reach statistical significance alone. However, the ratios of alpha(2)-adrenoceptor : I-sites in all six layers of OFC of depressed subjects were nearly half that of control subjects (P<0.008). In amygdalas from a different group of depressed patients there were no changes in alpha(2)-adrenoceptors or I-sites, or their ratios, compared with controls. The results support previous western blot data indicating a cortex-selective shift away from alpha(2)AR towards I-site preponderance in depressed patients.
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Affiliation(s)
- John E Piletz
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson 39216-4505, USA.
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Robinson ESJ, Tyacke RJ, Nutt DJ, Hudson AL. Distribution of [(3)H]BU224, a selective imidazoline I(2) binding site ligand, in rat brain. Eur J Pharmacol 2002; 450:55-60. [PMID: 12176109 DOI: 10.1016/s0014-2999(02)02076-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BU224 (2-(4,5-dihydroimidaz-2-yl)-quinoline) is a selective imidazoline I(2) binding site ligand characterised in both competition binding assays and functional studies. However, in some studies, BU224 has been reported to have a different functional effect from that seen with another selective imidazoline I(2) binding site ligand 2-BFI (2-(2-benzofuranyl)-2-imidazoline). This effect may reflect differing efficacies of the ligands or a difference in their brain distribution. The present study has investigated the distribution of the tritiated form of BU224 in rat brain and correlated this distribution with other imidazoline I(2) binding site ligands, [(3)H]idazoxan and [(3)H]2-BFI. Saturation studies revealed binding of [(3)H]BU224 was of high affinity and saturable. The central distribution of [(3)H]BU224 was similar to that previous reported for imidazoline I(2) binding site in rat brain. Autoradiography revealed that the highest levels of binding were in the arcuate nucleus, interpeduncular nucleus, area postrema, pineal gland and ependymal cell layer lining the ventricles. Correlation analysis of the binding distribution with our previous published studies revealed a highly significant correlation between [(3)H]BU224 and both [(3)H]idazoxan (r=0.94) and [(3)H]2-BFI (r=0.96). These data indicate [(3)H]BU224 labels the same population of imidazoline I(2) binding site in rat brain as seen with [(3)H]idazoxan and [(3)H]2-BFI. Therefore, the differences in functional effects observed with these compounds may reflect agonist and antagonist properties.
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Affiliation(s)
- Emma S J Robinson
- Psychopharmacology Unit, School of Medical Sciences, University of Bristol, University Walk, Bristol BS8 1TD, UK
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46
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Dardonville C, Rozas I, Callado LF, Meana JJ. I(2)-imidazoline binding site affinity of a structurally different type of ligands. Bioorg Med Chem 2002; 10:1525-33. [PMID: 11886814 DOI: 10.1016/s0968-0896(01)00420-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Two families of compounds with affinity towards the I(2) imidazoline binding sites are reported. The first is a family of compounds structurally related to agmatine with two guanidine or 2-aminoimidazoline groups at each end of an aliphatic chain of six, eight, nine or 12 methylene groups. Second, and following the model of clonidine, we propose another family of compounds also with two guanidine or 2-aminoimidazoline groups at each end of a chain consisting of two phenyl rings connected by groups such as CH(2), CO, NH and SO(2). The affinity of the compounds towards the I(2) imidazoline binding sites was then evaluated in human brain tissues. In order to determine their pharmacological selectivity versus alpha(2)-adrenoceptors, the affinity for these receptors was also evaluated for the compounds with the highest affinities at I(2) imidazoline binding sites. The results obtained show that many of the compounds exhibit a considerable affinity towards the I(2) imidazoline binding sites. The aliphatic derivatives, in particular, present a very interesting selectivity for the I(2) imidazoline binding sites versus the alpha(2) adrenoceptors. To better understand these findings, mono-guanidinium analogues of the aliphatic derivatives were synthesised and tested showing poor affinity for I(2) imidazoline binding sites. The importance of these results lies in the novelty of the chemical structures studied (dicationic aliphatic compounds particularly) because they are significantly different to those of the I(2) imidazoline binding site ligands reported to date.
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47
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Chung S, Kwon S, Kim Y, Ahn D, Lee Y, Nam T. Inhibition by clonidine of the carbachol-induced tension development and nonselective cationic current in guinea pig ileal myocytes. JAPANESE JOURNAL OF PHARMACOLOGY 2001; 87:125-33. [PMID: 11700011 DOI: 10.1254/jjp.87.125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Effects of clonidine, an imidazoline derivative as well as alpha2-adrenoceptor agonist, on carbachol (CCh)-evoked contraction in guinea pig ileal smooth muscle were studied using isometric tension recording. To investigate the cellular mechanisms of the inhibitory effect of clonidine, its effects on CCh-evoked nonselective cationic current (I(CCh)), voltage-dependent Ca2+ current (I(Ca)) and voltage-dependent K+ current (I(K)) was also studied using patch-clamp recording techniques in single ileal cells. Clonidine inhibited the contraction evoked by CCh (1 microM) in a concentration-dependent manner with an IC50 valve of 61.7 +/- 2.5 microM. High K+ (40 mM)-evoked contraction was only slightly inhibited even when clonidine was used at 300 microM. Externally applied clonidine inhibited I(CCh) dose-dependently with an IC50 of 42.0 +/- 2.6 microM. When applied internally via patch pipettes, clonidine was without effect. An I(CCh)-like current induced by GTPgammaS was also inhibited by bath application of clonidine. None of KU14R and BU224, both imidazoline receptor blockers, and yohimbine, an alpha2-adrenergic blocker, significantly affects the inhibitory effect of clonidine on I(CCh). Clonidine (300 microM) only slightly decreased membrane currents flowing through voltage-gated Ca2+ channels or K+ channels. These data indicate that clonidine relaxes smooth muscle contraction produced by muscarinic receptor activation and suggest that the effect of clonidine seems due mainly to inhibition of I(CCh) via acting directly on the involved cationic channel.
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Affiliation(s)
- S Chung
- Department of Physiology, College of Medicine, Yonsei University, Seoul, Korea
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48
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Halaris A, Piletz JE. Imidazoline receptors: possible involvement in the pathophysiology and treatment of depression. Hum Psychopharmacol 2001; 16:65-69. [PMID: 12404600 DOI: 10.1002/hup.185] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Imidazoline receptors (IR), a novel family of non-adrenergic receptors, are present in brain, especially the limbic system, and platelets among other organs. Their functions include central mediation of blood pressure control and possibly modulation of affective symptomatology. Studies of unipolar depressed patients have revealed consistent up-regulation of the I(1) subtype on the platelet. Treatment with cyclic antidepressants is accompanied by down-regulation in responders. Treatment with the non-cyclic bupropion produced similar findings. Studies of human post-mortem brain show changes in depressed subjects but the protein fragments assessed are of different molecular weights than in the platelet. Plasma agmatine is believed to be a putative endogenous ligand for I receptors. Thus, IR may be useful state markers of affective disorders. Copyright 2001 John Wiley & Sons, Ltd.
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Affiliation(s)
- Angelos Halaris
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, USA
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49
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Barrot M, Rettori MC, Guardiola-Lemaitre B, Jarry C, Le Moal M, Piazza PV. Interactions between imidazoline binding sites and dopamine levels in the rat nucleus accumbens. Eur J Neurosci 2000. [DOI: 10.1046/j.1460-9568.2000.01318.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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50
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Piletz JE, Zhu H, Ordway G, Stockmeier C, Dilly G, Reis D, Halaris A. Imidazoline receptor proteins are decreased in the hippocampus of individuals with major depression. Biol Psychiatry 2000; 48:910-9. [PMID: 11074229 DOI: 10.1016/s0006-3223(00)00892-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND A downregulation of I(2)-imidazoline binding sites has been reported in frontal cortices of depressed suicide victims, according to I(2)-radioligand binding and confirmed by Western blotting. We now report Western blots of imidazoline receptor proteins in hippocampi of subjects with and without depression at the time of death. METHODS Postmortem diagnoses were obtained from 17 cases of Axis I major depressive disorder and 17 cases without Axis I psychopathology. No psychotropic compounds were found in body fluids. Hippocampi were removed, sectioned, and assessed histologically. Throughout the analysis, each major depressive disorder sample was paired with a sample from a psychiatrically healthy subject based on equivalent life spans and postmortem delays. The antiserum was identical to that used in previous studies that reported a downregulation of cortical 29/30-kd imidazoline receptor-binding proteins in depression. RESULTS A triad of imidazoline receptor-binding protein bands (40-50 kd) was detected in the human hippocampus. Subjects with major depressive disorder had significantly less intensity in each imidazoline receptor-binding proteins band compared with control subjects (p =. 01 for overall bands). CONCLUSIONS The present results can be aligned with previous reports of downregulation of I(2)-radioligand binding sites in both cortices and platelets of depressed patients.
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Affiliation(s)
- J E Piletz
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA
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