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Barrett K, Ebert B, Remaly M. Silverlon: A Weapon Against Driveline Infections in Lvad Patients. J Heart Lung Transplant 2023. [DOI: 10.1016/j.healun.2023.02.1574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
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Sathyanarayanan A, Mueller TT, Ali Moni M, Schueler K, Baune BT, Lio P, Mehta D, Baune BT, Dierssen M, Ebert B, Fabbri C, Fusar-Poli P, Gennarelli M, Harmer C, Howes OD, Janzing JGE, Lio P, Maron E, Mehta D, Minelli A, Nonell L, Pisanu C, Potier MC, Rybakowski F, Serretti A, Squassina A, Stacey D, van Westrhenen R, Xicota L. Multi-omics data integration methods and their applications in psychiatric disorders. Eur Neuropsychopharmacol 2023; 69:26-46. [PMID: 36706689 DOI: 10.1016/j.euroneuro.2023.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 11/22/2022] [Accepted: 01/02/2023] [Indexed: 01/27/2023]
Abstract
To study mental illness and health, in the past researchers have often broken down their complexity into individual subsystems (e.g., genomics, transcriptomics, proteomics, clinical data) and explored the components independently. Technological advancements and decreasing costs of high throughput sequencing has led to an unprecedented increase in data generation. Furthermore, over the years it has become increasingly clear that these subsystems do not act in isolation but instead interact with each other to drive mental illness and health. Consequently, individual subsystems are now analysed jointly to promote a holistic understanding of the underlying biological complexity of health and disease. Complementing the increasing data availability, current research is geared towards developing novel methods that can efficiently combine the information rich multi-omics data to discover biologically meaningful biomarkers for diagnosis, treatment, and prognosis. However, clinical translation of the research is still challenging. In this review, we summarise conventional and state-of-the-art statistical and machine learning approaches for discovery of biomarker, diagnosis, as well as outcome and treatment response prediction through integrating multi-omics and clinical data. In addition, we describe the role of biological model systems and in silico multi-omics model designs in clinical translation of psychiatric research from bench to bedside. Finally, we discuss the current challenges and explore the application of multi-omics integration in future psychiatric research. The review provides a structured overview and latest updates in the field of multi-omics in psychiatry.
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Affiliation(s)
- Anita Sathyanarayanan
- Queensland University of Technology, Centre for Genomics and Personalised Health, School of Biomedical Sciences, Faculty of Health, Kelvin Grove, Queensland 4059, Australia
| | - Tamara T Mueller
- Institute for Artificial Intelligence and Informatics in Medicine, TU Munich, 80333 Munich, Germany
| | - Mohammad Ali Moni
- Artificial Intelligence and Digital Health Data Science, School of Health and Rehabilitation Sciences, Faculty of Health and Behavioural Sciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Katja Schueler
- Clinic for Psychosomatics, Hospital zum Heiligen Geist, Frankfurt am Main, Germany; Frankfurt Psychoanalytic Institute, Frankfurt am Main, Germany
| | - Bernhard T Baune
- Department of Psychiatry and Psychotherapy, University of Münster, Germany; Department of Psychiatry, Melbourne Medical School, University of Melbourne, Australia; The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Australia
| | - Pietro Lio
- Department of Computer Science and Technology, University of Cambridge, Cambridge, United Kingdom
| | - Divya Mehta
- Queensland University of Technology, Centre for Genomics and Personalised Health, School of Biomedical Sciences, Faculty of Health, Kelvin Grove, Queensland 4059, Australia.
| | | | - Bernhard T Baune
- Department of Psychiatry and Psychotherapy, University of Münster, Germany; Department of Psychiatry, Melbourne Medical School, University of Melbourne, Australia; The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Australia
| | - Mara Dierssen
- Center for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology; Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Bjarke Ebert
- Medical Strategy & Communication, H. Lundbeck A/S, Valby, Denmark
| | - Chiara Fabbri
- Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna, Italy; Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Paolo Fusar-Poli
- Early Psychosis: Intervention and Clinical-detection (EPIC) Lab, Department of Psychosis Studies, King's College London, United Kingdom; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Massimo Gennarelli
- Department of Molecular and Translational Medicine, University of Brescia; Genetics Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | | | - Oliver D Howes
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom; Psychiatric Imaging, Medical Research Council Clinical Sciences Centre, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | | | - Pietro Lio
- Department of Computer Science and Technology, University of Cambridge, Cambridge, United Kingdom
| | - Eduard Maron
- Department of Psychiatry, University of Tartu, Tartu, Estonia; Centre for Neuropsychopharmacology, Division of Brain Sciences, Imperial College London, London, United Kingdom; Documental Ltd, Tallin, Estonia; West Tallinn Central Hospital, Tallinn, Estonia
| | - Divya Mehta
- Queensland University of Technology, Centre for Genomics and Personalised Health, School of Biomedical Sciences, Faculty of Health, Kelvin Grove, Queensland 4059, Australia
| | - Alessandra Minelli
- Department of Molecular and Translational Medicine, University of Brescia; Genetics Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Lara Nonell
- MARGenomics, IMIM (Hospital del Mar Research Institute), Barcelona, Spain
| | - Claudia Pisanu
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, University of Cagliari, Cagliari, Italy
| | | | - Filip Rybakowski
- Department of Psychiatry, Poznan University of Medical Sciences, Poznan, Poland
| | - Alessandro Serretti
- Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna, Italy
| | - Alessio Squassina
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, University of Cagliari, Cagliari, Italy
| | - David Stacey
- British Heart Foundation Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom
| | - Roos van Westrhenen
- Parnassia Psychiatric Institute, Amsterdam, the Netherlands; Department of Psychiatry and Neuropsychology, Faculty of Health and Sciences, Maastricht University, Maastricht, the Netherlands; Institute of Psychiatry, Psychology & Neuroscience (IoPPN) King's College London, United Kingdom
| | - Laura Xicota
- Paris Brain Institute ICM, Salpetriere Hospital, Paris, France
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Blumenfeld A, Ettrup A, Hirman J, Ebert B, Cady R. Long-term reductions in disease impact in patients with chronic migraine following preventive treatment with eptinezumab. BMC Neurol 2022; 22:251. [PMID: 35804294 PMCID: PMC9264513 DOI: 10.1186/s12883-022-02774-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 06/27/2022] [Indexed: 11/18/2022] Open
Abstract
Background Eptinezumab is an anti-calcitonin gene-related peptide humanized monoclonal antibody approved for the preventive treatment of migraine in adults. The PREVAIL study demonstrated a favorable safety profile with sustained reductions in overall migraine-related burden in patients with chronic migraine (CM). This post hoc analysis aimed to examine item-level changes in the Migraine Disability Assessment (MIDAS) questionnaire over 2 years in participants with CM on eptinezumab treatment. Methods PREVAIL was an open-label, phase 3 trial that included 96 weeks of treatment where 128 adults received intravenous eptinezumab administered over 30 min every 12 weeks (wks) for up to 8 doses of 300 mg. MIDAS was administered at baseline, Wk12, and every 12wks thereafter. Two supplementary MIDAS items not included in the total score calculation assessed number of headache days in the past 3 months (MIDAS headache) and average headache pain severity (from 0 [none] to 10 [worst]). MIDAS total scores were summed from 5 items, each quantifying the number of days in the past 3 months with migraine-related disability. Items 1, 3, and 5 assessed absenteeism, namely how many days the patient missed work/school (Q1), household work (Q3), or family/social/leisure activities (Q5). Items 2 and 4 were measures of presenteeism, namely how many days the patient had reduced productivity in work/school (Q2) or household work (Q4). Results Mean MIDAS headache days decreased from 47.4 (baseline) to 17.1 (Wk12) and 16.3 (Wk104). The average headache pain severity score (0‒10) decreased from a mean of 7.3 (baseline) to 5.5 (Wk12) to 4.5 (Wk104). Mean MIDAS scores measuring absenteeism (Q1, 3, 5) changed from 9.7 days at baseline to 3.2 days (Wk12) and to 3.9 days (Wk104). Mean MIDAS scores measuring presenteeism (Q2, 4) at Wk12 decreased from 14.2 days at baseline to 5.2 days (Wk12, 104). Patients categorized with very severe MIDAS disability had a mean total MIDAS score of 84.8, with an average reduction of 56.7 days (Wk12), which was maintained at 32 days at Wk104. Conclusions Long-term treatment with eptinezumab in patients with CM suggested sustained reductions in MIDAS-quantified disability, consistent with the sustained reductions in headache frequency and pain severity. Trial registration ClinicalTrials.gov identifier: NCT02985398. Supplementary Information The online version contains supplementary material available at 10.1186/s12883-022-02774-3.
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Affiliation(s)
| | | | - Joe Hirman
- Pacific Northwest Statistical Consulting, Woodinville, WA, USA
| | | | - Roger Cady
- Lundbeck LLC, Deerfield, IL, USA. .,RK Consults, MO, 65721, Ozark, USA. .,Missouri State University, Springfield, MO, USA.
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Baune BT, Florea I, Ebert B, Touya M, Ettrup A, Hadi M, Ren H. Patient Expectations and Experiences of Antidepressant Therapy for Major Depressive Disorder: A Qualitative Study. Neuropsychiatr Dis Treat 2021; 17:2995-3006. [PMID: 34588779 PMCID: PMC8476086 DOI: 10.2147/ndt.s325954] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 08/27/2021] [Indexed: 12/13/2022] Open
Abstract
PURPOSE This qualitative study explored patient perceptions of the most burdensome symptoms of major depressive disorder (MDD), the impact of symptoms on patients' daily lives, and patient expectations and experiences regarding the timing of onset of antidepressant pharmacotherapy. PATIENTS AND METHODS Data were collected through facilitated, patient focus-group sessions in the USA between May and June 2019. Participants were adults with confirmed MDD who reported a major depressive episode within the past 2 years, for which they had received pharmacologic treatment for ≥6 weeks. The semi-structured discussion focused on the key topics of bothersome symptoms of MDD, the impact of symptoms on quality of life, and the effects of antidepressant treatment. Interviews were audio-recorded; findings were summarized using a content-analysis approach. RESULTS Five focus-group sessions were undertaken, involving a total of 29 patients (each attended one session; mean age, 43.4 years; 72.4% female). Mean time since confirmed diagnosis of MDD was 13.1 years. The most commonly prescribed antidepressants received were bupropion (41.4% of participants), escitalopram (34.5%), and sertraline (34.5%). The most frequently reported bothersome MDD symptoms were fatigue (mentioned by 58.6% of participants), lack of motivation/loss of interest (51.7%), anxiety/panic (44.8%), sadness (41.4%), and lack of concentration/brain fog (41.4%). Socialization, family life, and work were the areas in which quality of life was most impacted. Participants expressed dissatisfaction with their antidepressant treatment. Fast symptom resolution was mentioned as a priority (defined as <1 week by 38.5% of participants and ≤1 month by 65.4%). Most participants had not experienced fast relief from their symptoms with current or previous antidepressant medications. CONCLUSION Results of this qualitative study suggest that fatigue, anhedonia, cognitive symptoms, and anxiety are some of the most bothersome symptoms for patients with MDD and highlight the importance of obtaining rapid relief from these symptoms in order to improve outcomes and patient satisfaction with antidepressant medication.
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Affiliation(s)
- Bernhard T Baune
- Department of Psychiatry and Psychotherapy, University of Münster, Münster, Germany.,Department of Psychiatry, Melbourne Medical School, University of Melbourne, Melbourne, VIC, Australia.,The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Ioana Florea
- Clinical Development, H. Lundbeck A/S, Valby, Denmark
| | - Bjarke Ebert
- Medical Strategy & Communication, H. Lundbeck A/S, Valby, Denmark
| | | | - Anders Ettrup
- Medical Strategy & Communication, H. Lundbeck A/S, Valby, Denmark
| | - Monica Hadi
- Patient-Centered Research, Evidera, London, UK
| | - Hongye Ren
- Value Evidence, H. Lundbeck A/S, Valby, Denmark
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Dale E, Grunnet M, Pehrson AL, Frederiksen K, Larsen PH, Nielsen J, Stensbøl TB, Ebert B, Yin H, Lu D, Liu H, Jensen TN, Yang CR, Sanchez C. The multimodal antidepressant vortioxetine may facilitate pyramidal cell firing by inhibition of 5-HT 3 receptor expressing interneurons: An in vitro study in rat hippocampus slices. Brain Res 2017; 1689:1-11. [PMID: 29274875 DOI: 10.1016/j.brainres.2017.12.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 11/28/2017] [Accepted: 12/19/2017] [Indexed: 01/07/2023]
Abstract
The multimodal antidepressant vortioxetine is thought to mediate its pharmacological effects via 5-HT1A receptor agonism, 5-HT1B receptor partial agonism, 5-HT1D, 5-HT3, 5-HT7 receptor antagonism and 5-HT transporter inhibition. Here we studied vortioxetine's functional effects across species (canine, mouse, rat, guinea pig and human) in cellular assays with heterologous expression of 5-HT3A receptors (in Xenopus oocytes and HEK-293 cells) and in mouse neuroblastoma N1E-115 cells with endogenous expression of 5-HT3A receptors. Furthermore, we studied the effects of vortioxetine on activity of CA1 Stratum Radiatum interneurons in rat hippocampus slices using current- and voltage-clamping methods. The patched neurons were subsequently filled with biocytin for confirmation of 5-HT3 receptor mRNA expression by in situ hybridization. Whereas, both vortioxetine and the 5-HT3 receptor antagonist ondansetron potently antagonized 5-HT-induced currents in the cellular assays, vortioxetine had a slower off-rate than ondansetron in oocytes expressing 5-HT3A receptors. Furthermore, vortioxetine's but not ondansetron's 5-HT3 receptor antagonistic potency varied considerably across species. Vortioxetine had the highest potency at rat and the lowest potency at guinea pig 5-HT3A receptors. Finally, in 5-HT3 receptor-expressing GABAergic interneurons from the CA1 stratum radiatum, vortioxetine and ondansetron blocked depolarizations induced by superfusion of either 5-HT or the 5-HT3 receptor agonist mCPBG. Taken together, these data add to a growing literature supporting the idea that vortioxetine may inhibit GABAergic neurotransmission in some brain regions via a 5-HT3 receptor antagonism-dependent mechanism and thereby disinhibit pyramidal neurons and enhance glutamatergic signaling.
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Affiliation(s)
- Elena Dale
- Brintellix Science Team, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Copenhagen, Denmark
| | - Morten Grunnet
- Neuroscience Drug Discovery, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Copenhagen, Denmark
| | - Alan L Pehrson
- Brintellix Science Team, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Copenhagen, Denmark
| | - Kristen Frederiksen
- Neuroscience Drug Discovery, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Copenhagen, Denmark
| | - Peter H Larsen
- Neuroscience Drug Discovery, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Copenhagen, Denmark
| | - Jacob Nielsen
- Neuroscience Drug Discovery, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Copenhagen, Denmark
| | - Tine B Stensbøl
- Brintellix Science Team, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Copenhagen, Denmark
| | - Bjarke Ebert
- Brintellix Science Team, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Copenhagen, Denmark
| | - Haolan Yin
- ChemPartner Co. Ltd, 998 Halei Road, Zhangjiang Hi-Tech Park, Shanghai 201203, PR China
| | - Dunguo Lu
- ChemPartner Co. Ltd, 998 Halei Road, Zhangjiang Hi-Tech Park, Shanghai 201203, PR China
| | - Huiquing Liu
- ChemPartner Co. Ltd, 998 Halei Road, Zhangjiang Hi-Tech Park, Shanghai 201203, PR China
| | - Thomas N Jensen
- Neuroscience Drug Discovery, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Copenhagen, Denmark
| | - Charles R Yang
- ChemPartner Co. Ltd, 998 Halei Road, Zhangjiang Hi-Tech Park, Shanghai 201203, PR China
| | - Connie Sanchez
- Brintellix Science Team, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Copenhagen, Denmark; Translational Neuropsychiatry Unit, Aarhus University, Skovagervej 2, DK-8240 Risskov, Denmark.
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Ebert B, Miskowiak K, Kloster M, Johansen J, Eckholm C, Wærner T, Holme M, Bruun LM. An ethnographic study of the effects of cognitive symptoms in patients with major depressive disorder: the IMPACT study. BMC Psychiatry 2017; 17:370. [PMID: 29157207 PMCID: PMC5697414 DOI: 10.1186/s12888-017-1523-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 10/27/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The manifestation of major depressive disorder (MDD) may include cognitive symptoms that can precede the onset of MDD and persist beyond the resolution of acute depressive episodes. However, little is known about how cognitive symptoms are experienced by MDD patients and the people around them. METHODS In this international (Brazil, Canada, China, France, and Germany) ethnographic study, we conducted semi-structured interviews and observations of remitted as well as symptomatic MDD patients (all patients self-reported being diagnosed by an HCP and self-reported being on an antidepressant) aged 18-60 years with self-reported cognitive symptoms (N = 34). In addition, participating depressed patients' close family or friends (N = 31) were interviewed. Separately recruited from depressed participants, work colleagues (N = 21) and healthcare providers (HCPs; N = 13) of depressed individuals were interviewed. RESULTS Key insights were that: (1) patients were generally unaware that their cognitive symptoms were linked to their depression and, instead, attributed these symptoms to negative aspects of their person (e.g., age, separate disease, laziness, exhaustion); (2) cognitive symptoms in MDD appeared to negatively impact patients' social relationships and patients' ability to handle daily tasks at work and at home; (3) patients' cognitive symptoms also impacted relationships with family members and coworkers; (4) patients' cognitive symptoms increased stress and feelings of failure, which in turn seemed to worsen the cognitive symptoms, thereby creating a destructive cycle; and (5) although HCPs recommended that patients re-engage in everyday activities to help overcome their depression, cognitive symptoms seemed to impede such functional recovery. CONCLUSIONS Taken together, these findings highlight a negative impact of patients' cognitive symptoms on their social functioning, work performance, and quality of life on the people close to them, and consequently on the degree of functional recovery after depression.
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Affiliation(s)
- Bjarke Ebert
- , H. Lundbeck A/S, Ottiliavej 9, 2500, Valby, Denmark.
| | - Kamilla Miskowiak
- Psychiatric Centre Copenhagen, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100 København Ø, Denmark
| | - Morten Kloster
- ReD Associates, Kronprinsessegade 20, DK-1306 København, Denmark
| | - Jon Johansen
- H. Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark
| | - Cara Eckholm
- ReD Associates, Kronprinsessegade 20, DK-1306 København, Denmark
| | | | - Mads Holme
- ReD Associates, Kronprinsessegade 20, DK-1306 København, Denmark
| | - Louise Meldgaard Bruun
- 0000 0004 0512 597Xgrid.154185.cAarhus University Hospital, Skovagervej 2, 8240 Risskov, Denmark
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Medek D, Katelaris C, Erbas B, Lampugnani ER, Newbiggin E, Haberle S, Huete A, Beggs PJ, Ebert B, van Klinken R, Davies JM. P56: IMPLEMENTATION OF THE AUSPOLLEN PARTNERSHIP PROJECT AND PRE-EVALUATION SURVEY OF USER PERCEPTION OF THE VALUE OF LOCAL POLLEN INFORMATION. Intern Med J 2017. [DOI: 10.1111/imj.56_13578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- D Medek
- Australian National University; Canberra Australia
| | - C Katelaris
- Campbelltown Hospital & Western Sydney University; Sydney Australia
| | - B Erbas
- LaTrobe University; Melbourne Australia
| | | | - E Newbiggin
- The University of Melbourne; Melbourne Australia
| | - S Haberle
- Australian National University; Canberra Australia
| | - A Huete
- University of Technology Sydney; Sydney Australia
| | - PJ Beggs
- Macquarie University; Sydney Australia
| | - B Ebert
- Bureau of Meteorology; Melbourne Australia
| | - R van Klinken
- Commonwealth Scientific and Industrial Research Organisation; Brisbane Australia
| | - JM Davies
- Queensland University of Technology & Metro North Hospital and Health Service; Brisbane Australia
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Buonamici S, Perino S, Lim K, Darman R, Feala J, Peng S, Bhavsar E, Corson L, Keaney G, Mizui Y, Obeng E, Park E, Wang J, Warmuth M, Yu L, Zhu P, Furman R, Ebert B, Smith P. 21 SF3B1 MUTATIONS INDUCE ABERRANT SPLICING LEADING TO A BLOCK IN ERYTHROID DIFFERENTIATION AND COMPETITIVE ADVANTAGE. Leuk Res 2015. [DOI: 10.1016/s0145-2126(15)30022-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Hammer H, Ebert B, Jensen HS, Jensen AA. Functional characterization of the 1,5-benzodiazepine clobazam and its major active metabolite N-desmethylclobazam at human GABA(A) receptors expressed in Xenopus laevis oocytes. PLoS One 2015; 10:e0120239. [PMID: 25798598 PMCID: PMC4370687 DOI: 10.1371/journal.pone.0120239] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Accepted: 02/04/2015] [Indexed: 12/13/2022] Open
Abstract
The 1,5-benzodiazepine clobazam is indicated for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome in patients 2 years of age or older in the United States, and for treatment of anxiety and various forms of epilepsy elsewhere. Clobazam has been reported to exhibit different in vivo adverse effects and addiction liability profile than the classic 1,4-benzodiazepines. In this study, it was investigated whether the in vitro pharmacological properties of clobazam and its major active metabolite N-desmethylclobazam could explain some of these clinical differences. The functional properties of the two 1,5-benzodiazepines were characterized at the human γ-aminobutyric acid type A receptor (GABAAR) subtypes α1β2γ2S, α2β2γ2S, α3β2γ2S, α5β2γ2S and α6β2δ expressed in Xenopus laevis oocytes by use of two-electrode voltage-clamp electrophysiology and compared to those exhibited by the 1,4-benzodiazepine clonazepam. All three compounds potentiated GABA EC20-evoked responses through the α1,2,3,5β2γ2S GABAARs in a reversible and concentration-dependent manner, with each displaying similar EC50 values at the four subtypes. Furthermore, the degrees of potentiation of the GABA EC20 currents through the four receptors mediated by saturating modulator concentrations did not differ substantially for any of the three benzodiazepines. The three compounds were substantially less potent (200-3900 fold) as positive allosteric modulators at the α6β2δ GABAAR than at the α1,2,3,5β2γ2S receptors. Interestingly, however, clobazam and especially N-desmethylclobazam were highly efficacious potentiators of α6β2δ receptor signaling. Although this activity component is unlikely to contribute to the in vivo effects of clobazam/N-desmethylclobazam, the 1,5-benzodiazepine could constitute an interesting lead for novel modulators targeting this low-affinity binding site in GABAARs. In conclusion, the non-selective modulation exerted by clobazam, N-desmethylclobazam and clonazepam at the α1β2γ2S, α2β2γ2S, α3β2γ2S and α5β2γ2S GABAARs indicate that the observed clinical differences between clobazam and 1,4-benzodiazepines are likely to arise from factors other than their respective pharmacological properties at the GABAARs as investigated here.
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Affiliation(s)
- Harriet Hammer
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Anders A. Jensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
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Klauenberg K, Walzel M, Ebert B, Elster C. Informative prior distributions for ELISA analyses. Biostatistics 2015; 16:454-64. [DOI: 10.1093/biostatistics/kxu057] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 10/29/2014] [Indexed: 11/13/2022] Open
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Hoestgaard-Jensen K, O'Connor RM, Dalby NO, Simonsen C, Finger BC, Golubeva A, Hammer H, Bergmann ML, Kristiansen U, Krogsgaard-Larsen P, Bräuner-Osborne H, Ebert B, Frølund B, Cryan JF, Jensen AA. The orthosteric GABAA receptor ligand Thio-4-PIOL displays distinctly different functional properties at synaptic and extrasynaptic receptors. Br J Pharmacol 2014; 170:919-32. [PMID: 23957253 DOI: 10.1111/bph.12340] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 08/06/2013] [Accepted: 08/11/2013] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND AND PURPOSE Explorations into the heterogeneous population of native GABA type A receptors (GABAA Rs) and the physiological functions governed by the multiple GABAA R subtypes have for decades been hampered by the lack of subtype-selective ligands. EXPERIMENTAL APPROACH The functional properties of the orthosteric GABAA receptor ligand 5-(4-piperidyl)-3-isothiazolol (Thio-4-PIOL) have been investigated in vitro, ex vivo and in vivo. KEY RESULTS Thio-4-PIOL displayed substantial partial agonist activity at the human extrasynaptic GABAA R subtypes expressed in Xenopus oocytes, eliciting maximal responses of up to ∼30% of that of GABA at α5 β3 γ2S , α4 β3 δ and α6 β3 δ and somewhat lower efficacies at the corresponding α5 β2 γ2S , α4 β2 δ and α6 β2 δ subtypes (maximal responses of 4-12%). In contrast, it was an extremely low efficacious agonist at the α1 β3 γ2S , α1 β2 γ2S , α2 β2 γ2S , α2 β3 γ2S , α3 β2 γ2S and α3 β3 γ2S GABAA Rs (maximal responses of 0-4%). In concordance with its agonism at extrasynaptic GABAA Rs and its de facto antagonism at the synaptic receptors, Thio-4-PIOL elicited robust tonic currents in electrophysiological recordings on slices from rat CA1 hippocampus and ventrobasal thalamus and antagonized phasic currents in hippocampal neurons. Finally, the observed effects of Thio-4-PIOL in rat tests of anxiety, locomotion, nociception and spatial memory were overall in good agreement with its in vitro and ex vivo properties. CONCLUSION AND IMPLICATIONS The diverse signalling characteristics of Thio-4-PIOL at GABAA Rs represent one of the few examples of a functionally subtype-selective orthosteric GABAA R ligand reported to date. We propose that Thio-4-PIOL could be a useful pharmacological tool in future studies exploring the physiological roles of native synaptic and extrasynaptic GABAA Rs.
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Affiliation(s)
- K Hoestgaard-Jensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Jensen HS, Nichol K, Lee D, Ebert B. Clobazam and its active metabolite N-desmethylclobazam display significantly greater affinities for α₂- versus α₁-GABA(A)-receptor complexes. PLoS One 2014; 9:e88456. [PMID: 24533090 PMCID: PMC3922815 DOI: 10.1371/journal.pone.0088456] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 01/07/2014] [Indexed: 01/09/2023] Open
Abstract
Clobazam (CLB), a 1,5-benzodiazepine (BZD), was FDA-approved in October 2011 for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients 2 years and older. BZDs exert various CNS effects through allosteric modulation of GABAA receptors. The structurally distinct, 1,4-BZD clonazepam (CLN) is also approved to treat LGS. The precise mechanisms of action and clinical efficacy of both are unknown. Data show that the GABAA α1-subunit–selective compound zolpidem [ZOL] exhibits hypnotic/sedative effects. Conversely, data from knock-in mice carrying BZD binding site mutations suggest that the α2 subunit mediates anticonvulsant effects, without sedative actions. Hence, the specific pattern of interactions across the GABAA receptor complexes of BZDs might be reflected in their clinical efficacies and adverse effect profiles. In this study, GABAA-receptor binding affinities of CLB, N-desmethylclobazam (N-CLB, the major metabolite of CLB), CLN, and ZOL were characterized with native receptors from rat-brain homogenates and on cloned receptors from HEK293 cells transfected with combinations of α (α1, α2, α3, or α5), β2, and γ2 subtypes. Our results demonstrate that CLB and N-CLB have significantly greater binding affinities for α2- vs. α1-receptor complexes, a difference not observed for CLN, for which no distinction between α2 and α1 receptors was observed. Our experiments with ZOL confirmed the high preference for α1 receptors. These results provide potential clues to a new understanding of the pharmacologic modes of action of CLB and N-CLB.
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Affiliation(s)
- Henrik Sindal Jensen
- Synaptic Transmission, Neuroscience Drug Discovery, H. Lundbeck A/S, Valby, Denmark
- * E-mail:
| | - Kathryn Nichol
- Medical Affairs, Lundbeck LLC, Deerfield, Illinois, United States of America
| | - Deborah Lee
- Clinical Affairs, Lundbeck LLC, Deerfield, Illinois, United States of America
| | - Bjarke Ebert
- Department of Electrophysiology, H. Lundbeck A/S, Valby, Denmark
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Wei Y, Dimicoli S, Bueso-Ramos C, Chen R, Yang H, Neuberg D, Pierce S, Jia Y, Zheng H, Wang H, Wang X, Nguyen M, Wang SA, Ebert B, Bejar R, Levine R, Abdel-Wahab O, Kleppe M, Ganan-Gomez I, Kantarjian H, Garcia-Manero G. Toll-like receptor alterations in myelodysplastic syndrome. Leukemia 2013; 27:1832-40. [PMID: 23765228 DOI: 10.1038/leu.2013.180] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 05/28/2013] [Accepted: 06/03/2013] [Indexed: 02/03/2023]
Abstract
Recent studies have implicated the innate immunity system in the pathogenesis of myelodysplastic syndromes (MDS). Toll-like receptor (TLR) genes encode key innate immunity signal initiators. We recently identified multiple genes, known to be regulated by TLRs, to be overexpressed in MDS bone marrow (BM) CD34+ cells, and hypothesized that TLR signaling is abnormally activated in MDS. We analyzed a large cohort of MDS cases and identified TLR1, TLR2 and TLR6 to be significantly overexpressed in MDS BM CD34+ cells. Deep sequencing followed by Sanger resequencing of TLR1, TLR2, TLR4 and TLR6 genes uncovered a recurrent genetic variant, TLR2-F217S, in 11% of 149 patients. Functionally, TLR2-F217S results in enhanced activation of downstream signaling including NF-κB activity after TLR2 agonist treatment. In cultured primary BM CD34+ cells of normal donors, TLR2 agonists induced histone demethylase JMJD3 and interleukin-8 gene expression. Inhibition of TLR2 in BM CD34+ cells from patients with lower-risk MDS using short hairpin RNA resulted in increased erythroid colony formation. Finally, RNA expression levels of TLR2 and TLR6, as well as presence of TLR2-F217S, are associated with distinct prognosis and clinical characteristics. These findings indicate that TLR2-centered signaling is deregulated in MDS, and that its targeting may have potential therapeutic benefit in MDS.
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Affiliation(s)
- Y Wei
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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Christensen T, Bétry C, Mnie-Filali O, Etievant A, Ebert B, Haddjeri N, Wiborg O. Synergistic antidepressant-like action of gaboxadol and escitalopram. Eur Neuropsychopharmacol 2012; 22:751-60. [PMID: 22406239 DOI: 10.1016/j.euroneuro.2012.02.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 12/21/2011] [Accepted: 02/04/2012] [Indexed: 11/28/2022]
Abstract
According to current theories on the etiopathogenesis and pathophysiology of depression, both GABAergic and monoaminergic transmitter systems are perturbed. Consequently, the present study addressed the putative antidepressant action of the sedative-hypnotic GABAA receptor agonist, gaboxadol, separately and in combination with the selective serotonin reuptake inhibitor (SSRI) escitalopram. The rat chronic mild stress model was used to test the chronic antidepressant properties of gaboxadol in this depression model. Sucrose intake used as a read-out on anhedonic-like behavior indicated that the drug response rate for gaboxadol (5 mg/kg/day, i.p.) was similar to that measured for escitalopram (5 mg/kg/day, i.p.), however, the rate increased when the two drugs were co-administered, suggesting a synergistic action. Using in vivo electrophysiological recordings in dorsal raphe nucleus (DRN) of anesthetised rats, the present results showed that one week treatment with gaboxadol (5 mg/kg/day, i.p.) or with escitalopram (5 mg/kg/day, i.p.), followed by a 24 h washout period, did not affect DRN 5-HT neuronal firing per se, but in rats treated with both drugs for one week, the firing rate of DRN 5-HT neurons was significantly increased. Immunohistochemical estimations of cell proliferation in the hippocampal dentate gyrus did not reveal any effect of gaboxadol on chronic mild stressed rats, indicating that neurogenesis per se is not systematically associated with recovery from anhedonic-like behavior. Taken together, our data reveal for the first time an antidepressant action of gaboxadol and indicate a synergistic mechanism, regarding rapid onset of action and efficacy, when co-administered with escitalopram.
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Affiliation(s)
- Trine Christensen
- Centre for Psychiatric Research, Aarhus University Hospital, Skovagervej 2, 8240 Risskov, Denmark
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15
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Vardya I, Hoestgaard-Jensen K, Nieto-Gonzalez JL, Dósa Z, Boddum K, Holm MM, Wolinsky TD, Jones KA, Dalby NO, Ebert B, Jensen K. Positive modulation of δ-subunit containing GABA(A) receptors in mouse neurons. Neuropharmacology 2012; 63:469-79. [PMID: 22579928 DOI: 10.1016/j.neuropharm.2012.04.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Revised: 04/20/2012] [Accepted: 04/23/2012] [Indexed: 12/23/2022]
Abstract
δ-subunit containing extrasynaptic GABA(A) receptors are potential targets for modifying neuronal activity in a range of brain disorders. With the aim of gaining more insight in synaptic and extrasynaptic inhibition, we used a new positive modulator, AA29504, of δ-subunit containing GABA(A) receptors in mouse neurons in vitro and in vivo. Whole-cell patch-clamp recordings were carried out in the dentate gyrus in mouse brain slices. In granule cells, AA29504 (1 μM) caused a 4.2-fold potentiation of a tonic current induced by THIP (1 μM), while interneurons showed a potentiation of 2.6-fold. Moreover, AA29504 (1 μM) increased the amplitude and prolonged the decay of miniature inhibitory postsynaptic currents (mIPSCs) in granule cells, and this effect was abolished by Zn²⁺ (15 μM). AA29504 (1 μM) also induced a small tonic current (12.7 ± 3.2 pA) per se, and when evaluated in a nominally GABA-free environment using Ca²⁺ imaging in cultured neurons, AA29504 showed GABA(A) receptor agonism in the absence of agonist. Finally, AA29504 exerted dose-dependent stress-reducing and anxiolytic effects in mice in vivo. We propose that AA29504 potentiates δ-containing GABA(A) receptors to enhance tonic inhibition, and possibly recruits perisynaptic δ-containing receptors to participate in synaptic phasic inhibition in dentate gyrus.
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Affiliation(s)
- Irina Vardya
- Synaptic Physiology Laboratory, Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark
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Asbjorn Jensen A, Hammer H, Ebert B, Sindal Jensen H. Clobazam and Its Active Metabolite, N-Desmethylclobazam, Are Partial Benzodiazepine Receptor Agonists at Cloned GABAA Receptors Expressed in Xenopus leavis Oocytes (P05.085). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.p05.085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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17
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Techau Bruun A, Sindal Jensen H, Ebert B. Modelling of Clobazam's Interactions with the Benzodiazepine Binding Site and Analysis of Structural Receptor Subtype Differences (P05.084). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.p05.084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Sindal Jensen H, Ebert B. Clobazam and Its Active Metabolite, N-Desmethylclobazam, Are High-Affinity Ligands for the Benzodiazepine Sites of GABAA Receptors (P05.086). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.p05.086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Bejar R, Stevenson K, Abdel-Wahab O, Galili N, Nilsson B, Garcia-Manero G, Kantarjian H, Raza A, Levine R, Neuberg D, Ebert B. 288 Point mutations in myelodysplastic syndromes: Associations with clinical features and independent predictors of overall survival. Leuk Res 2011. [DOI: 10.1016/s0145-2126(11)70290-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Madsen KK, Ebert B, Clausen RP, Krogsgaard-Larsen P, Schousboe A, White HS. Selective GABA transporter inhibitors tiagabine and EF1502 exhibit mechanistic differences in their ability to modulate the ataxia and anticonvulsant action of the extrasynaptic GABA(A) receptor agonist gaboxadol. J Pharmacol Exp Ther 2011; 338:214-9. [PMID: 21450931 DOI: 10.1124/jpet.111.179671] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Modulation of the extracellular levels of GABA via inhibition of the synaptic GABA transporter GAT1 by the clinically effective and selective GAT1 inhibitor tiagabine [(R)-N-[4,4-bis(3-methyl-2-thienyl)-3-butenyl]nipecotic acid; Gabitril] has proven to be an effective treatment strategy for focal seizures. Even though less is known about the therapeutic potential of other GABA transport inhibitors, previous investigations have demonstrated that N-[4,4-bis(3-methyl-2-thienyl)-3-butenyl]-3-hydroxy-4-(methylamino)-4,5,6,7-tetrahydrobenzo[d]isoxazol-3-ol (EF1502), which, like tiagabine, is inactive on GABA(A) receptors, inhibits both GAT1 and the extrasynaptic GABA and betaine transporter BGT1, and exerts a synergistic anticonvulsant effect when tested in combination with tiagabine. In the present study, the anticonvulsant activity and motor impairment associated with systemic administration of gaboxadol (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol), which, at the doses used in this study (i.e., 1-5 mg/kg) selectively activates extrasynaptic α4-containing GABA(A) receptors, was determined alone and in combination with either tiagabine or EF1502 using Frings audiogenic seizure-susceptible and CF1 mice. EF1502, when administered in combination with gaboxadol, resulted in reduced anticonvulsant efficacy and Rotarod impairment associated with gaboxadol. In contrast, tiagabine, when administered in combination with gaboxadol, did not modify the anticonvulsant action of gaboxadol or reverse its Rotarod impairment. Taken together, these results highlight the mechanistic differences between tiagabine and EF1502 and support a functional role for BGT1 and extrasynaptic GABA(A) receptors.
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Affiliation(s)
- Karsten K Madsen
- Department of Pharmacology and Pharmacotherapy, Faculty of Pharmaceutical Sciences, University of Copenhagen, Copenhagen, Denmark.
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Svetnik V, Ferri R, Ray S, Ma J, Walsh JK, Snyder E, Ebert B, Deacon S. Alterations in cyclic alternating pattern associated with phase advanced sleep are differentially modulated by gaboxadol and zolpidem. Sleep 2010; 33:1562-70. [PMID: 21102998 PMCID: PMC2954706 DOI: 10.1093/sleep/33.11.1562] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE to evaluate cyclic alternating pattern (CAP) in a phase advance model of transient insomnia and the effects of gaboxadol and zolpidem. DESIGN a randomized, double-blind, cross-over study in which habitual sleep time was advanced by 4 h. SETTING 6 sleep research laboratories in US PARTICIPANTS: 55 healthy subjects (18-57 y) INTERVENTIONS Gaboxadol 15 mg (GBX), zolpidem 10 mg (ZOL), and placebo (PBO). MEASUREMENTS routine polysomnographic (PSG) measures, CAP, spectral power density, and self-reported sleep measures RESULTS The phase advance model of transient insomnia produced significant changes in CAP parameters. Both GBX and ZOL significantly and differentially modified CAP parameters in the direction of more stable sleep. GBX brought the CAP rate in stage 1 sleep and slow wave sleep (SWS) closer to baseline levels but did not significantly change the CAP rate in stage 2. ZOL reduced the CAP rate in stage 2 to near baseline levels, whereas the CAP rate in stage 1 and SWS was reduced substantially below baseline levels. The CAP parameter A1 index (associated with SWS and sleep continuity) showed the highest correlation with self-reported sleep quality, higher than any traditional PSG, spectral, or other self-reported measures. CONCLUSION disruptions in CAP produced by phase advanced sleep were significantly and differentially modulated by gaboxadol and zolpidem. The relative independence of CAP parameters from other electrophysiological measures of sleep, their high sensitivity to sleep disruption, and their strong association with subjective sleep quality suggest that CAP variables may serve as valuable endpoints in future insomnia research.
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Affiliation(s)
- Vladimir Svetnik
- Merck Svetnik Laboratories, Biometrics Research, Rahway, NJ 07065, USA.
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Abstract
The activation characteristics of synaptic and extrasynaptic GABA(A) receptors are important for shaping the profile of phasic and tonic inhibition in the central nervous system, which will critically impact on the activity of neuronal networks. Here, we study in isolation the activity of three agonists, GABA, muscimol and 4,5,6,7-tetrahydoisoxazolo[5,4-c]pyridin-3(2H)-one (THIP), to further understand the activation profiles of alpha 1 beta 3 gamma 2, alpha 4 beta 3 gamma 2 and alpha 4 beta 3 delta receptors that typify synaptic- and extrasynaptic-type receptors expressed in the hippocampus and thalamus. The agonists display an order of potency that is invariant between the three receptors, which is reliant mostly on the agonist dissociation constant. At delta subunit-containing extrasynaptic-type GABA(A) receptors, both THIP and muscimol additionally exhibited, to different degrees, superagonist behaviour. By comparing whole-cell and single channel currents induced by the agonists, we provide a molecular explanation for their different activation profiles. For THIP at high concentrations, the unusual superagonist behaviour on alpha 4 beta 3 delta receptors is a consequence of its ability to increase the duration of longer channel openings and their frequency, resulting in longer burst durations. By contrast, for muscimol, moderate superagonist behaviour was caused by reduced desensitisation of the extrasynaptic-type receptors. The ability to specifically increase the efficacy of receptor activation, by selected exogenous agonists over that obtained with the natural transmitter, may prove to be of therapeutic benefit under circumstances when synaptic inhibition is compromised or dysfunctional.
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Affiliation(s)
- Martin Mortensen
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
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Abstract
The development of novel drugs falls into two completely different categories: truly novel drugs and drugs that can be considered as improvements of further advanced and eventually marketed drugs. The risk of failure and the reason for failure by these two classes of compounds obviously are very different. Truly novel drugs often rely on pharmacological data obtained in preclinical models paired with a scientific rationale for a mechanism thought to be relevant for the phenotype of the disease. The scientific insight into both the mechanisms underlying the disease and how these diseases can be manipulated by pharmacological means is therefore essential for the success of the drug. In practical terms, this means that a thorough understanding of the disease is a prerequisite for success. It is therefore a sobering thought that most of these compounds fail due to marginal efficacy in Phase II or III trials. The lack of success of these compounds may reflect either lack of knowledge of the disease, poor predictive value of the preclinical models, large heterogeneity in the underlying mechanisms for a given phenotype, or the use of the compound in a population that doesn't express a phenotype optimal for the drug. This year's list of discontinued compounds spans the range from truly innovative drugs to 'me-too' compounds and as such is highly useful in illustrating the current dilemmas for the pharmaceutical industry.
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Affiliation(s)
- Bjarke Ebert
- Department of Electrophysiology, H Lundbeck A/S, Ottiliavej 9, Valby, 2500, Denmark.
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Stegk JP, Ebert B, Martin HJ, Maser E. Expression profiles of human 11beta-hydroxysteroid dehydrogenases type 1 and type 2 in inflammatory bowel diseases. Mol Cell Endocrinol 2009; 301:104-8. [PMID: 19022342 DOI: 10.1016/j.mce.2008.10.030] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 10/22/2008] [Accepted: 10/22/2008] [Indexed: 01/26/2023]
Abstract
Inflammatory bowel diseases such as Crohn's disease (CD) and ulcerative colitis (UC) are characterized by an increase in pro-inflammatory cytokines. On the other hand, endogenous cortisol is regarded as physiological compound to combat inflammation. The local activation of glucocorticoids is mediated by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) which increases cortisol, and 11beta-HSD2 which decreases cortisol concentrations. We hypothesized that in inflamed tissues of patients suffering from inflammatory bowel diseases 11beta-HSD1 is upregulated whereas 11beta-HSD2 is downregulated. By using quantitative real-time PCR, we investigated the transcription levels of 11beta-HSD1 and 11beta-HSD2 in patients diagnosed with CD or UC. Expression of 11beta-HSD1 was significantly elevated in inflamed tissue compared to non-inflamed colonic tissue in both, CD (2.7-fold) and UC (3.8-fold), whereas 11beta-HSD2 expression was decreased in the same samples. In both diseases, male patients showed a more pronounced upregulation of 11beta-HSD1 (CD: 4.8-fold, UC: 6.5-fold) compared to females (CD: 1.8-fold, UC: 1.8-fold), a fact which might be due to the higher levels of circulating anti-inflammatory estrogens in women. Our data support the hypothesis that both enzymes play a crucial role in inflammation by affecting local tissue ratios between active and inactive glucocorticoids.
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Affiliation(s)
- J P Stegk
- Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig-Holstein, Brunswiker Strasse 10, Kiel, Germany
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Søgaard R, Ebert B, Klaerke D, Werge T. Triton X-100 inhibits agonist-induced currents and suppresses benzodiazepine modulation of GABA(A) receptors in Xenopus oocytes. Biochim Biophys Acta 2009; 1788:1073-80. [PMID: 19366585 DOI: 10.1016/j.bbamem.2009.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2008] [Revised: 01/16/2009] [Accepted: 02/03/2009] [Indexed: 11/29/2022]
Abstract
Changes in lipid bilayer elastic properties have been proposed to underlie the modulation of voltage-gated Na(+) and L-type Ca(2+) channels and GABA(A) receptors by amphiphiles. The amphiphile Triton X-100 increases the elasticity of lipid bilayers at micromolar concentrations, assessed from its effects on gramicidin channel A appearance rate and lifetime in artificial lipid bilayers. In the present study, the pharmacological action of Triton-X 100 on GABA(A) receptors expressed in Xenopus laevis oocytes was examined. Triton-X 100 inhibited GABA(A) alpha(1)beta(3)gamma(2S) receptor currents in a noncompetitive, time- and voltage-dependent manner and increased the apparent rate and extent of desensitization at 10 muM, which is 30 fold below the critical micelle concentration. In addition, Triton X-100 induced picrotoxin-sensitive GABA(A) receptor currents and suppressed allosteric modulation by flunitrazepam at alpha(1)beta(3)gamma(2S) receptors. All effects were independent of the presence of a gamma(2S) subunit in the GABA(A) receptor complex. The present study suggests that Triton X-100 may stabilize open and desensitized states of the GABA(A) receptor through changes in lipid bilayer elasticity.
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Affiliation(s)
- Rikke Søgaard
- Institute of Cellular and Molecular Medicine, Panum 12.6, University of Copenhagen, Blegdamsvej 3C, DK-2200, Copenhagen N, Denmark.
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Cremers TIFH, de Vries MG, Huinink KD, van Loon JP, v d Hart M, Ebert B, Westerink BHC, De Lange ECM. Quantitative microdialysis using modified ultraslow microdialysis: direct rapid and reliable determination of free brain concentrations with the MetaQuant technique. J Neurosci Methods 2008; 178:249-54. [PMID: 19135084 DOI: 10.1016/j.jneumeth.2008.12.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 12/04/2008] [Accepted: 12/06/2008] [Indexed: 10/21/2022]
Abstract
The only method to quantify free extracellular levels of drugs in the brain of living animals is microdialysis. However, quantitative microdialysis has been hampered by methodological issues for decades. The problems arise from the need to establish the in vivo recovery for appropriate quantitation. In dealing with these issues the "dynamic no-net-flux" (DNNF) method seemed to be the experimental method of choice. Major disadvantages were, however, the need for a very high degree of bioanalytical precision and accuracy and the need for a large number of animals. Moreover, today we know that the experimental data are not always straightforward. To improve robustness and practicality of quantitative microdialysis sampling we modified the ultraslow microdialysis approach. Ultraslow microdialysis uses very low microdialysis flow rates (<200 nl/min) which increase recovery (both in vivo and in vitro) to over 90%. However, new practical issues arise when attempting to work with these flow rates. The resulting very low volumes and long lag times make this method very impractical for general application. In the modified version, addition of a carrier flow after the dialysis process has been completed, which negates the problems of long lag times and low volumes. The resulting dilution of the dialysis sample concentration can simply be mathematically corrected. In the current study we measured the free brain levels of two CNS compounds using the classic DNNF and the new modified ultraslow dialysis method. Modified ultraslow microdialysis was shown to generate robust data with the use of only small numbers of rats. The method is a promising tool for common straightforward screening of blood-brain barrier penetration of compounds into the brain.
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Ebert B, Anderson NJ, Cremers TI, Rasmussen S, Vogel V, Fahey JM, Sánchez C. Gaboxadol — a different hypnotic profile with no tolerance to sleep EEG and sedative effects after repeated daily dosing. Pharmacol Biochem Behav 2008; 90:113-22. [DOI: 10.1016/j.pbb.2008.01.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Revised: 01/17/2008] [Accepted: 01/22/2008] [Indexed: 10/22/2022]
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Madsen C, Jensen AA, Liljefors T, Kristiansen U, Nielsen B, Hansen CP, Larsen M, Ebert B, Bang-Andersen B, Krogsgaard-Larsen P, Frølund B. 5-Substituted imidazole-4-acetic acid analogues: synthesis, modeling, and pharmacological characterization of a series of novel gamma-aminobutyric acid(C) receptor agonists. J Med Chem 2007; 50:4147-61. [PMID: 17655213 DOI: 10.1021/jm070447j] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of ring-substituted analogues of imidazole-4-acetic acid (IAA, 4), a partial agonist at both GABAA and GABAC receptors (GABA = gamma-aminobutyric acid), have been synthesized. The synthesized compounds 8a-l have been evaluated as ligands for the alpha1beta2gamma2S GABAA receptors and the rho1 GABAC receptors using the FLIPR membrane potential (FMP) assay and by electrophysiology techniques. None of the tested compounds displayed activity at the GABAA receptors at concentrations up to 1000 microM. However, the 5-Me, 5-Ph, 5-p-Me-Ph, and 5-p-F-Ph IAA analogues, 8a,c,f,g, displayed full agonist activities at the rho1 receptors in the FMP assay (EC50 in the range 22-420 microM). Ligand-protein docking identified the Thr129 in the alpha1 subunit and the corresponding Ser168 residue in rho1 as determinants of the selectivity displayed by the 5-substituted IAA analogues. The fact that GABA, 4, and 8a displayed decreased agonist potencies at a rho1Ser168Thr mutant compared to the WT rho1 receptor strongly supported this hypothesis. However, in contrast to GABA and 4, which exhibited increased agonist potencies at a alpha1(Thr129Ser)beta2gamma2 mutant compared to WT GABAA receptor, the data obtained for 8a at the WT and mutant receptors were nonconclusive.
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Affiliation(s)
- Christian Madsen
- Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, DK-2100 Copenhagen, Denmark
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Friemel A, Ebert B, Hutson PH, Brust P, Nieber K, Deuther-Conrad W. Postnatal development and kinetics of [3H]gaboxadol binding in rat brain: in vitro homogenate binding and quantitative autoradiography. Brain Res 2007; 1170:39-47. [PMID: 17692833 DOI: 10.1016/j.brainres.2007.07.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2007] [Revised: 07/11/2007] [Accepted: 07/12/2007] [Indexed: 10/23/2022]
Abstract
The postnatal development of the binding of the GABA(A) receptor agonist [(3)H]gaboxadol in rat brain was investigated. Using brain tissue from rats obtained at postnatal days 1, 10, 25, and >25 (adult), the binding of [(3)H]gaboxadol and the benzodiazepine [(3)H]flunitrazepam to GABA(A) receptors was compared in homogenate binding assays and quantitative receptor autoradiography. Kinetic and equilibrium data obtained in homogenate binding studies revealed two different [(3)H]gaboxadol affinities. A kinetically derived K(D) of 3.7 nM in adult cerebellum, calculated from the association and dissociation rate constants k(on) (1.45 x 10(8) M(-1) min(-1)) and k(off) (0.54 min(-1)) was contrasted by an equilibrium K(D) of 38.6 nM, obtained by homologous competition experiments. Quantitative analysis of autoradiographic data revealed an increase in specific [(3)H]gaboxadol binding sites during brain development, which resembles the anatomical and temporal pattern of the postnatal expression of the extrasynaptic delta subunit of GABA(A) receptors. In conclusion, by the radioligand binding data obtained on native tissue, binding of gaboxadol to GABA(A) receptors located outside the synaptic junctions could be postulated.
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Affiliation(s)
- Anne Friemel
- Department of Radiopharmacy, Institute of Interdisciplinary Isotope Research, Permoserstr. 15, 04318 Leipzig, Germany
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Michelsen S, Sánchez C, Ebert B. Lack of generalisation between the GABAA receptor agonist, gaboxadol, and allosteric modulators of the benzodiazepine binding site in the rat drug discrimination procedure. Psychopharmacology (Berl) 2007; 193:151-7. [PMID: 17361395 DOI: 10.1007/s00213-007-0750-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Accepted: 02/19/2007] [Indexed: 12/23/2022]
Abstract
INTRODUCTION The binding sites for gamma-aminobutyric acid (GABA) and GABA(A) receptor agonists are located differently from the binding sites for benzodiazepine receptor agonists. Furthermore, the major pharmacological effects of benzodiazepine receptor agonists and the GABA(A) receptor agonist gaboxadol (4,5,6,7-tetrahydrroisoxazolo(5,4-c)pyridin-3-ol, THIP) are mediated by different GABA(A) receptor subunit compositions; that is, gaboxadol may interact primarily with extra-synaptically located alpha(4)beta(2/3)delta-containing receptors and benzodiazepines with the synaptically located alpha(1)beta(2/3)gamma(2)-containing receptors. OBJECTIVES The aim of the present study was to address if this different receptor subtype selectivity was reflected in vivo. MATERIALS AND METHODS A two-lever liquid reinforced operant discrimination procedure was conducted. Three groups of rats were trained to discriminate gaboxadol, diazepam and zolpidem 5.5, 1.5 and 0.7 mg/kg i.p., respectively, from vehicle. RESULTS Substitution tests showed that gaboxadol-trained animals failed to recognize diazepam (0.75-1.5 mg/kg), zolpidem (0.4-0.7 mg/kg), zopiclone (2.5 mg/kg), zaleplon (1.0-1.5 mg/kg) or indiplon (0.31 mg/kg). In contrast, all benzodiazepine receptor agonists, but not gaboxadol (4.5-5.5 mg/kg), generalised to the discriminative stimulus in diazepam- and zolpidem-trained animals. DISCUSSION In agreement with these data, the competitive benzodiazepine receptor antagonist flumazenil (10 mg/kg s.c.) antagonised the discriminative stimulus of zolpidem but not of gaboxadol. Interaction tests showed no synergistic interaction of concomitant administration of gaboxadol and zolpidem or diazepam. CONCLUSION Previous studies have shown that gaboxadol and benzodiazepines interact with different receptor populations, and the present study confirms that in vivo functional consequences of this receptor selectivity exist in the form of differential behavioural responses in rats.
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Affiliation(s)
- Signe Michelsen
- Department of Neuropharmacology, H. Lundbeck A/S, Ottiliavej 9, 2500, Copenhagen, Valby, Denmark
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Vogensen SB, Frydenvang K, Greenwood JR, Postorino G, Nielsen B, Pickering DS, Ebert B, Bølcho U, Egebjerg J, Gajhede M, Kastrup JS, Johansen TN, Clausen RP, Krogsgaard-Larsen P. A Tetrazolyl-Substituted Subtype-Selective AMPA Receptor Agonist⊥. J Med Chem 2007; 50:2408-14. [PMID: 17455929 DOI: 10.1021/jm061439q] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Replacement of the methyl group of the AMPA receptor agonist 2-amino-3-[3-hydroxy-5-(2-methyl-2H-5-tetrazolyl)-4-isoxazolyl]propionic acid (2-Me-Tet-AMPA) with a benzyl group provided the first AMPA receptor agonist, compound 7, capable of discriminating GluR2-4 from GluR1 by its more than 10-fold preference for the former receptor subtypes. An X-ray crystallographic analysis of this new analogue in complex with the GluR2-S1S2J construct shows that accommodation of the benzyl group creates a previously unobserved pocket in the receptor, which may explain the remarkable pharmacological profile of compound 7.
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Affiliation(s)
- Stine B Vogensen
- Department of Medicinal Chemistry, The Faculty of Pharmaceutical Sciences, University of Copenhagen, 2 Universitetsparken, DK-2100 Copenhagen, Denmark
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Frølund B, Jensen LS, Storustovu SI, Stensbøl TB, Ebert B, Kehler J, Krogsgaard-Larsen P, Liljefors T. 4-aryl-5-(4-piperidyl)-3-isoxazolol GABAA antagonists: synthesis, pharmacology, and structure-activity relationships. J Med Chem 2007; 50:1988-92. [PMID: 17375905 DOI: 10.1021/jm070038n] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of 4-aryl-5-(4-piperidyl)-3-isoxazolol GABAA antagonists have been synthesized and pharmacologically characterized. The meta-phenyl-substituted compounds 9k and 9m and the para-phenoxy-substituted compound 9l all display high affinities (Ki=10-70 nM) and antagonist potencies in the low nanomolar range (Ki=9-10 nM). These potencies are significantly higher than those of previously reported 4-PIOL antagonists and considerably higher than that of the standard GABAA antagonist SR 95531.
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Affiliation(s)
- Bente Frølund
- Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, DK-2100 Copenhagen, Denmark.
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Cremers T, Ebert B. Plasma and CNS concentrations of Gaboxadol in rats following subcutaneous administration. Eur J Pharmacol 2007; 562:47-52. [PMID: 17362924 DOI: 10.1016/j.ejphar.2007.01.017] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Revised: 12/18/2006] [Accepted: 01/03/2007] [Indexed: 11/25/2022]
Abstract
Gaboxadol has been suggested to be a selective extrasynaptic GABA(A) receptor agonist. However, there is little information on Gaboxadol concentrations in the central nervous system (CNS) at therapeutically relevant doses. In order to investigate this, rats were injected subcutaneously with Gaboxadol and plasma and CNS concentrations were determined using the dynamic-no-net-flux and ultraslow microdialysis methods. Results using the 2 methods were similar and showed that Gaboxadol rapidly entered the brain and that peak CNS concentrations after 2.5, 5 and 10 mg/kg were in the range of 0.7 to 3 microM. Furthermore, a very short half-life (28 min) in both plasma and CNS was observed. It is concluded that concentrations of Gaboxadol in the CNS are in a range, which are likely to activate only extrasynaptic (nongamma subunit containing) GABA(A) receptors.
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Affiliation(s)
- Thomas Cremers
- Brains-on-Line, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
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Abstract
Chronic insomnia affects a significant proportion of young adult and elderly populations. Treatment strategies should alleviate nighttime symptoms, the feeling of nonrestorative sleep, and impaired daytime function. Current pharmacological approaches focus primarily on GABA, the major inhibitory neurotransmitter in the central nervous system. Benzodiazepine receptor agonists (BzRA) have been a mainstay of pharmacotherapy; the classical benzodiazepines and non-benzodiazepines share a similar mode of action and allosterically enhance inhibitory chloride currents through the GABA(A) receptor, a ligand-gated protein comprising 5 subunits pseudosymmetrically arranged around a core anion channel. Variations in GABA(A) receptor subunit composition confer unique pharmacological, biophysical, and electrophysiological properties on each receptor subtype. Classical benzodiazepines bind non-selectively to GABA(A) receptors containing a gamma2 subunit, whereas non-benzodiazepine hypnotics bind with higher relative affinity to alpha1-containing receptors. The non-benzodiazepine compounds generally represent an improvement over benzodiazepines as a result of improved binding selectivity and pharmacokinetic profiles. However, the enduring potential for amnestic effects, next day residual sedation, and abuse and physical dependence, particularly at higher doses, underscores the need for new treatment strategies. Novel pharmacotherapies in development act on systems believed to be specifically involved in the regulation of the sleep-wake cycle. The recently approved melatonin receptor agonist, ramelteon, targets circadian mechanisms. Gaboxadol, an investigational treatment and a selective extrasynaptic GABA(A) receptor agonist (SEGA), targets GABA(A) receptors containing a delta subunit, which are located outside the synaptic junctions of thalamic and cortical neurons thought to play an important regulatory role in the onset, maintenance, and depth of the sleep process.
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Affiliation(s)
- Bjarke Ebert
- Department of Electrophysiology, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Valby, Copenhagen, Denmark.
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Conti P, De Amici M, Pinto A, Tamborini L, Grazioso G, Frølund B, Nielsen B, Thomsen C, Ebert B, De Micheli C. Synthesis of 3-Hydroxy- and 3-Carboxy-Δ2-isoxazoline Amino Acids and Evaluation of Their Interaction with GABA Receptors and Transporters. European J Org Chem 2006. [DOI: 10.1002/ejoc.200600628] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Ebert B. GABA(A) receptor inhibition - site matters! Acta Physiol (Oxf) 2006; 188:151. [PMID: 17054654 DOI: 10.1111/j.1748-1716.2006.01622_1.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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38
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Kehlker J, Dahl O, Ebert B, Krogsgaard-larsen P. Preparation of Novel Piperidine Phosphinic Acid Analogues of the Inhibitory Neurotransmitter γ-Aminobutyric Acid (GABA). PHOSPHORUS SULFUR 2006. [DOI: 10.1080/10426509908053562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Jan Kehlker
- a Dept. Medicinal Chemistry , The Royal Danish School of Pharmacy
| | - Otto Dahl
- b Dept. Organic Chemistry , University of Copenhagen , Universitetsparken, 2100 KBH, Denmark
| | - Bjarke Ebert
- a Dept. Medicinal Chemistry , The Royal Danish School of Pharmacy
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Thomas A, Kümmel S, Ebert B, Fischer T. Verbesserte Differenzierung von 300 Brustläsionen durch die Realtime-Elastographie. Geburtshilfe Frauenheilkd 2006. [DOI: 10.1055/s-2006-952848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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40
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Thomas A, Fischer T, Frey H, Ohlinger R, Grunwald S, Blohmer JU, Winzer KJ, Weber S, Kristiansen G, Ebert B, Kümmel S. Real-time elastography--an advanced method of ultrasound: First results in 108 patients with breast lesions. Ultrasound Obstet Gynecol 2006; 28:335-40. [PMID: 16909438 DOI: 10.1002/uog.2823] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
OBJECTIVES To evaluate whether real-time elastography, a new, non-invasive method for the diagnosis of breast cancer, improves the differentiation and characterization of benign and malignant breast lesions. METHODS Real-time elastography was carried out in 108 potential breast tumor patients with cytologically or histologically confirmed focal breast lesions (59 benign, 49 malignant; median age, 53.9 years; range, 16-84 years). Tumor and healthy tissue were differentiated by measurement of elasticity based on the correlation between tissue properties and elasticity modulus. Evaluation was performed using the three-dimensional (3D) finite element method, in which the information is color-coded and superimposed on the B-mode ultrasound image. A second observer evaluated the elastography images, in order to improve the objectivity of the method. The results of B-mode scan and elastography were compared with those of histology and previous sonographic findings. Sensitivities and specificities were calculated, taking histology as the gold standard. RESULTS B-mode ultrasound had a sensitivity of 91.8% and a specificity of 78%, compared with sensitivities of 77.6% and 79.6% and specificities of 91.5% and 84.7%, respectively, for the two observers evaluating elastography. Agreement between B-mode ultrasound and elastography was good, yielding a weighted kappa of 0.67. CONCLUSIONS Our initial clinical results suggest that real-time elastography improves the specificity of breast lesion diagnosis and is a promising new approach for the diagnosis of breast cancer. Elastography provides additional information for differentiating malignant BI-RADS (breast imaging reporting and data system) category IV lesions.
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Affiliation(s)
- A Thomas
- Department of Obstetrics and Gynecology, Charité-Universitätsmedizin Berlin, Charité Campus Mitte, Berlin, Germany.
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Frølund B, Ebert B, Lawrence LW, Hurt SD, Krogsgaard-Larsen P. Synthesis and receptor binding of 5-amino[3H]2methyl-3-isothiazolol ([3H]thiomuscimol), a specific GABAa agonist photoaffinity label. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.2580360909] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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42
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Jensen TN, Nielsen J, Frederiksen K, Ebert B. Molecular cloning and pharmacological characterization of serotonin 5-HT(3A) receptor subtype in dog. Eur J Pharmacol 2006; 538:23-31. [PMID: 16647053 DOI: 10.1016/j.ejphar.2006.03.050] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2005] [Revised: 02/28/2006] [Accepted: 03/20/2006] [Indexed: 11/22/2022]
Abstract
In order to establish if the canine 5-hydroxytryptamine type 3A (5-HT(3A)) receptors share the pharmacological profile with human 5-HT(3A) receptors, we cloned and performed a molecular pharmacological characterization of the canine 5-HT(3A) receptor. The 5-HT(3A) cDNA was cloned from canine brain by polymerase chain reaction amplification. It encodes a 483 amino acid peptide that exhibits from 80% (mice) to 90% (ferrets) identity to other sequenced mammalian 5-HT(3A) receptors. The receptor agonists 5-hydroxytryptamine (5-HT) and meta-chlorophenylbiguanide (mCPBG) showed little differences between the two species, whereas 2-methyl-5-hydroxytryptamine (2-Me-5-HT) was ten times weaker at canine receptors than at human receptors. The potencies at the canine 5-HT(3) receptors were 9.9 microM (5-HT), 79 microM (2-Me-5-HT) and 0.8 microM (mCPBG). The selective, competitive receptor antagonist ondansetron was ten times more potent at human receptors compared to canine receptors (K(b)=0.9 nM), while (+)-tubocurarine was 1000-fold more potent at canine receptors (K(b)=3.0 nM) than at human receptors. Examination of the presumed ligand binding extracellular domain revealed one residue, where the canine receptor differs from all previously characterized 5-HT(3A) receptors, i.e. other species contain a conserved Trp(195), whereas the canine orthologue contains a Leu(195). To address the differences in potencies at the human and canine 5-HT(3A) receptors seen in this study, we introduced a L195W point mutation in the canine orthologue. Data showed that the 195 residue can affect receptor agonist potency and efficacy as well as antagonist potency, but did produce a pharmacological profile identical to the human orthologue. We therefore conclude that position 195 is strongly involved in the receptor-ligand interaction, but additional residues must contribute to the overall pharmacological profile.
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MESH Headings
- Amino Acid Sequence
- Animals
- Biguanides/pharmacology
- Cloning, Molecular
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Dogs/genetics
- Dose-Response Relationship, Drug
- Female
- Membrane Potentials/drug effects
- Molecular Sequence Data
- Mutation
- Ondansetron/pharmacology
- Oocytes/drug effects
- Oocytes/metabolism
- Oocytes/physiology
- Receptors, Serotonin, 5-HT3/genetics
- Receptors, Serotonin, 5-HT3/physiology
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Serotonin/pharmacology
- Serotonin Antagonists/pharmacology
- Serotonin Receptor Agonists/pharmacology
- Xenopus
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Affiliation(s)
- Thomas N Jensen
- Department of Electrophysiology, H. Lundbeck A/S, 9 Ottiliavej, DK-2500 Valby, Denmark
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Haining W, Ebert B, Subramanian A, Golub T, Kaech S, Wherry E, Nadler L. Transcriptional mapping of the anti-viral T cell response shows that impaired memory differentiation causes T cell dysfunction. Biol Blood Marrow Transplant 2006. [DOI: 10.1016/j.bbmt.2005.11.239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Krehan D, Storustovu SI, Liljefors T, Ebert B, Nielsen B, Krogsgaard-Larsen P, Frølund B. Potent 4-Arylalkyl-Substituted 3-Isothiazolol GABAA Competitive/Noncompetitive Antagonists: Synthesis and Pharmacology. J Med Chem 2006; 49:1388-96. [PMID: 16480274 DOI: 10.1021/jm050987l] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The GABA(A) agonists muscimol (1), 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP, gaboxadol, 3), and the partial GABA(A) agonist 5-(4-piperidyl)-3-isoxazolol (4-PIOL, 6a) and their respective 3-isothiazolol analogues thiomuscimol (2), thio-THIP (4), and thio-4-PIOL (7a) are ligands at the GABA(A) orthosteric (recognition) site. The structure-activity relationships (SARs) between these structures are key elements of a 3D-pharmacophore model for GABA(A) agonists and competitive antagonists [Frølund, B.; Jørgensen, A. T.; Tagmose, L.; Stensbøl, T. B.; Vestergaard, H. T.; Engblom, C.; Kristiansen, U.; Sanchez, C.; Krogsgaard-Larsen, P.; Liljefors, T. J. Med. Chem. 2002, 45, 2454-2468]. Prompted by this model, we now report the synthesis and SAR of a series of analogues of 7a, in which the 4-position of the 3-isothiazolol was substituted by alkyl or bulky aromatic groups such as naphthylmethyl and diphenylalkyl groups (7b-h). The compounds have been pharmacologically characterized using receptor binding assays and two-electrode voltage-clamped Xenopus oocytes expressing alpha1beta3gamma2S- and alpha4beta3delta-containing receptors. The compounds show SARs comparable with those of 6b-h but are generally 5-15 times more potent. The 2-naphthylmethyl, the 1-bromo-2-naphthylmethyl, and the 3,3-diphenylpropyl analogues, compounds 7e, 7f, and 7h, respectively, show affinity in the low-nanomolar range (K(i) 2-10 nM). Interestingly, 7e and 7h exhibited a mixed antagonist profile consisting of a noncompetitive component in the picomolar range and a competitive component at concentrations above 1 nM. This unique profile was shown not to be due to either use dependence or kinetic effects. This antagonist profile of 7e and 7h was particularly pronounced at alpha4beta3delta-containing GABA(A) receptors, which showed three- and 10-fold selectivity for 7h and 6h, respectively.
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Affiliation(s)
- Dorte Krehan
- Department of Medicinal Chemistry, The Danish University of Pharmaceutical Sciences, DK-2100 Copenhagen, Denmark
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45
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Friemel A, Hutson P, Ebert B, Brust P, Deuther-Conrad W. [3H]Gaboxadol binding sites characterised by in vitro autoradiography on pig brain and homogenate studies in rat. Neuroimage 2006. [DOI: 10.1016/j.neuroimage.2006.04.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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46
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Abstract
Drugs that enhance synaptic gamma-aminobutyric acid (GABA)ergic neurotransmission are widely utilized in the clinical setting. Barbiturates and benzodiazepine receptor agonists, for example, both potentiate an inhibitory chloride conductance through GABA-gated channels, and thereby achieve their sedative-hypnotic effects. The primary locus of action of these agents, and indeed most neuroactive drugs, is the postsynaptic junction. By contrast, gaboxadol, a selective extrasynaptic GABA receptor agonist and late-stage investigational treatment for insomnia, acts on a unique delta-containing GABAA receptor subtype found exclusively outside of the synapse. Although the mechanistic details of extrasynaptic neurotransmission remain to be fully established, it is now clear that these receptors demonstrate unique pharmacological, biophysical and electrophysiological properties. Importantly, the delta-containing GABAA receptor subtype activated by gaboxadol is highly expressed in the thalamus, where it might behave as a 'gain control' (independently controlling the strength of signals) in the corticothalamic pathways that govern sleep-relevant neuronal oscillations. This unique mechanism has contributed to our increased understanding of sleep mechanisms, and targeting of this system offers potential advantages over existing insomnia treatments.
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Affiliation(s)
- Keith A Wafford
- Merck, Sharp & Dohme, Neuroscience Research Centre, Terlings Park, Eastwick Road, Harlow, Essex CM20 2QR, UK.
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Stórustovu SI, Ebert B. Pharmacological Characterization of Agonists at δ-Containing GABAA Receptors: Functional Selectivity for Extrasynaptic Receptors Is Dependent on the Absence of γ2. J Pharmacol Exp Ther 2005; 316:1351-9. [PMID: 16272218 DOI: 10.1124/jpet.105.092403] [Citation(s) in RCA: 171] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Several groups have characterized the pharmacology of alpha4- or alpha6beta3delta-containing GABA(A) receptors expressed in different cell systems. We have previously demonstrated that the pharmacological profiles of a series of GABA(A) receptor agonists are highly dependent on the alpha subunit and little on the beta and gamma subunits, so to further understand the contribution of the different subunits in the GABA(A) receptor complex, we characterized a series of full agonists, partial agonists, and antagonists at alpha4beta3, alpha4beta3delta, and alpha6beta3delta receptors expressed in Xenopus oocytes. Little or no difference was seen when the compounds were compared at alphabeta- and alphabetadelta-containing receptors, whereas a significant reduction in both potency and relative efficacy was observed compared with alphabetagamma-containing receptors described in the literature. These data clearly confirm that the presence of the delta subunit in heterotrimeric receptors is a strong determinant of the increased pharmacological activity of compounds with agonist activity. The very similar agonist pharmacology of alphabeta- and alphabetadelta-containing receptors, which is significantly different from that of alphabetagamma-containing receptors, shows that whereas the presence of a gamma subunit impairs the response to an agonist stimulation of the alphabeta receptor complex, the delta subunit does not affect this in any way. Taken together, these data are well in line with the idea that alpha4beta3delta may contribute to the pharmacological action of exogenously applied agonists and may explain why systemically active compounds such as gaboxadol and muscimol in vivo appear to act as selective extrasynaptic GABA(A) agonists.
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Affiliation(s)
- Signe I Stórustovu
- Department of Electrophysiology, H. Lundbeck A/S, 9 Ottiliavej, DK-2500 Valby, Denmark
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Borghese CM, Stórustovu SÍ, Ebert B, Herd MB, Belelli D, Lambert JJ, Marshall G, Wafford KA, Harris RA. The delta subunit of gamma-aminobutyric acid type A receptors does not confer sensitivity to low concentrations of ethanol. J Pharmacol Exp Ther 2005; 316:1360-8. [PMID: 16272217 DOI: 10.1124/jpet.105.092452] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
GABA(A) receptors (GABA(A)Rs) are usually formed by alpha, beta, and gamma or delta subunits. Recently, delta-containing GABA(A)Rs expressed in Xenopus oocytes were found to be sensitive to low concentrations of ethanol (1-3 mM). Our objective was to replicate and extend the study of the effect of ethanol on the function of alpha4beta3delta GABA(A)Rs. We independently conducted three studies in two systems: rat and human GABA(A)Rs expressed in Xenopus oocytes, studied through two-electrode voltage clamp; and human GABA(A)Rs stably expressed in the fibroblast L(tk-) cell line, studied through patch-clamp electrophysiology. In all cases, alpha4beta3delta GABA(A)Rs were only sensitive to high concentrations of ethanol (100 mM in oocytes, 300 mM in the cell line). Expression of the delta subunit in oocytes was assessed through the magnitude of the maximal GABA currents and sensitivity to zinc. Of the three rat combinations studied, alpha4beta3 was the most sensitive to ethanol, isoflurane, and 5alpha-pregnan-3alpha,21-diol-20-one (THDOC); alpha4beta3delta and alpha4beta3gamma(2S) were very similar in most aspects, but alpha4beta3delta was more sensitive to GABA, THDOC, and lanthanum than alpha4beta3gamma(2S) GABA(A)Rs. Ethanol at 30 mM did not affect tonic GABA-mediated currents in dentate gyrus reported to be mediated by GABA(A)Rs incorporating alpha4 and delta subunits. We have not been able to replicate the sensitivity of alpha4beta3delta GABA(A)Rs to low concentrations of ethanol in four different laboratories in independent studies. This suggests that as yet unidentified factors may play a critical role in the ethanol effects on delta-containing GABA(A)Rs.
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Affiliation(s)
- Cecilia M Borghese
- The University of Texas at Austin, Waggoner Center for Alcohol and Addiction Research, 1 University Station A4800, Austin, TX 78712-0159, USA
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Resch-Genger U, Hoffmann K, Nietfeld W, Engel A, Neukammer J, Nitschke R, Ebert B, Macdonald R. How to Improve Quality Assurance in Fluorometry: Fluorescence-Inherent Sources of Error and Suited Fluorescence Standards. J Fluoresc 2005; 15:337-62. [PMID: 15986157 DOI: 10.1007/s10895-005-2630-3] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2004] [Accepted: 01/28/2005] [Indexed: 10/25/2022]
Abstract
The scope of this paper is to illustrate the need for an improved quality assurance in fluorometry. For this purpose, instrumental sources of error and their influences on the reliability and comparability of fluorescence data are highlighted for frequently used photoluminescence techniques ranging from conventional macro- and microfluorometry over fluorescence microscopy and flow cytometry to microarray technology as well as in vivo fluorescence imaging. Particularly, the need for and requirements on fluorescence standards for the characterization and performance validation of fluorescence instruments, to enhance the comparability of fluorescence data, and to enable quantitative fluorescence analysis are discussed. Special emphasis is dedicated to spectral fluorescence standards and fluorescence intensity standards.
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Affiliation(s)
- U Resch-Genger
- Federal Institute for Materials Research and Testing, Working Group Optical Spectroscopy, Division I.3, BAM, Berlin, Germany,
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Vogensen SB, Clausen RP, Greenwood JR, Johansen TN, Pickering DS, Nielsen B, Ebert B, Krogsgaard-Larsen P. Convergent Synthesis and Pharmacology of Substituted Tetrazolyl-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid Analogues. J Med Chem 2005; 48:3438-42. [PMID: 15857151 DOI: 10.1021/jm050014l] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis and pharmacological characterization of 1- and 2-alkyltetrazolyl analogues of (RS)-2-amino-3-[3-hydroxy-5-(2-methyl-2H-5-tetrazolyl)-4-isoxazolyl]propionic acid (2-Me-Tet-AMPA), a highly potent and selective agonist at AMPA receptors, are presented. A shorter and more convergent synthetic route than previously described, employing a new method for introducing the amino acid moiety, was developed for these derivatives. The 2-substituted isomers were selective agonists, and their activity correlated inversely with the size of the substituent. Structural explanations of the structure-activity relationship are provided.
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Affiliation(s)
- Stine B Vogensen
- Department of Medicinal Chemistry and Department of Pharmacology, The Danish University of Pharmaceutical Sciences, 2 Universitetsparken, DK-2100 Copenhagen, Denmark
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