1
|
Bojić MG, Treven M, Pandey KP, Tiruveedhula VVNPB, Santrač A, Đukanović Đ, Vojinović N, Amidžić L, Škrbić R, Scholze P, Ernst M, Cook JM, Savić MM. Vascular effects of midazolam, flumazenil, and a novel imidazobenzodiazepine MP-III-058 on isolated rat aorta. Can J Physiol Pharmacol 2024; 102:206-217. [PMID: 37909404 DOI: 10.1139/cjpp-2023-0285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
Hypotensive influences of benzodiazepines and other GABAA receptor ligands, recognized in clinical practice, seem to stem from the existence of "vascular" GABAA receptors in peripheral blood vessels, besides any mechanisms in the central and peripheral nervous systems. We aimed to further elucidate the vasodilatatory effects of ligands acting through GABAA receptors. Using immunohistochemistry, the rat aortic smooth muscle layer was found to express GABAA γ2 and α1-5 subunit proteins. To confirm the role of "vascular" GABAA receptors, we investigated the vascular effects of standard benzodiazepines, midazolam, and flumazenil, as well as the novel compound MP-III-058. Using two-electrode voltage clamp electrophysiology and radioligand binding assays, MP-III-058 was found to have modest binding but substantial functional selectivity for α5β3γ2 over other αxβ3γ2 GABAA receptors. Tissue bath assays revealed comparable vasodilatory effects of MP-III-058 and midazolam, both of which at 100 µmol/L concentrations had efficacy similar to prazosin. Flumazenil exhibited weak vasoactivity per se, but significantly prevented the relaxant effects of midazolam and MP-III-058. These studies indicate the existence of functional GABAA receptors in the rat aorta, where ligands exert vasodilatory effects by positive modulation of the benzodiazepine binding site, suggesting the potential for further quest for leads with optimized pharmacokinetic properties as prospective adjuvant vasodilators.
Collapse
Affiliation(s)
- Milica Gajić Bojić
- Faculty of Medicine, Center for Biomedical Research, University of Banja Luka, Banja Luka 78000, Republic of Srpska, Bosnia and Herzegovina
| | - Marco Treven
- Neurology Department, Medical University of Vienna, Vienna, Austria
| | - Kamal P Pandey
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - V V N Phani Babu Tiruveedhula
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Anja Santrač
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Belgrade 11000, Serbia
| | - Đorđe Đukanović
- Faculty of Medicine, Center for Biomedical Research, University of Banja Luka, Banja Luka 78000, Republic of Srpska, Bosnia and Herzegovina
| | - Nataša Vojinović
- Faculty of Medicine, Center for Biomedical Research, University of Banja Luka, Banja Luka 78000, Republic of Srpska, Bosnia and Herzegovina
| | - Ljiljana Amidžić
- Faculty of Medicine, Center for Biomedical Research, University of Banja Luka, Banja Luka 78000, Republic of Srpska, Bosnia and Herzegovina
| | - Ranko Škrbić
- Faculty of Medicine, Center for Biomedical Research, University of Banja Luka, Banja Luka 78000, Republic of Srpska, Bosnia and Herzegovina
| | - Petra Scholze
- Department of Pathobiology of the Nervous SystemCenter for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Margot Ernst
- Department of Pathobiology of the Nervous SystemCenter for Brain Research, Medical University of Vienna, Vienna, Austria
| | - James M Cook
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Miroslav M Savić
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Belgrade 11000, Serbia
| |
Collapse
|
2
|
Al-Kuraishy HM, Al-Gareeb AI, Alsayegh AA, Abusudah WF, Almohmadi NH, Eldahshan OA, Ahmed EA, Batiha GES. Insights on benzodiazepines' potential in Alzheimer's disease. Life Sci 2023; 320:121532. [PMID: 36858314 DOI: 10.1016/j.lfs.2023.121532] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 02/16/2023] [Accepted: 02/22/2023] [Indexed: 03/02/2023]
Abstract
Alzheimer's disease (AD) is the most frequent type of dementia characterized by the deposition of amyloid beta (Aβ) plaque and tau-neurofibrillary tangles (TNTs) in the brain. AD is associated with the disturbances of various neurotransmitters including gamma-aminobutyric acid (GABA). Of note, GABA is reduced in AD, and restoration of GABA effect by benzodiazepines (BDZs) may improve AD outcomes. However, BDZs may adversely affect cognitive functions chiefly in elderly AD patients with sleep disorders. Besides, there is a controversy regarding the use of BDZs in AD. Consequently, the objective of the present review was to disclose the possible role of BDZs on the pathogenesis of AD that might be beneficial, neutral, or detrimental effects on AD. Prolonged use of intermediate-acting BDZ lorazepam exerts amnesic effects due to attenuation of synaptic plasticity and impairment of recognition memory. However, BDZs may have a protective effect against the development of AD by reducing tau phosphorylation, neuroinflammation, and progression of AD neuropathology. On the other side, other findings highlighted that extended use of BDZs was not associated with the development of AD. In conclusion, there are controversial points concerning the use of BDZs and the risk for the progression of AD. Thus, preclinical, and clinical studies are essential in this regard.
Collapse
Affiliation(s)
- Hayder M Al-Kuraishy
- Department of Clinical Pharmacology and Medicine, College of Medicine, Al-Mustansiriya University, Bagdad, Iraq
| | - Ali I Al-Gareeb
- Department of Clinical Pharmacology and Medicine, College of Medicine, Al-Mustansiriya University, Bagdad, Iraq
| | - Abdulrahman A Alsayegh
- Clinical Nutrition Department Applied Medical Sciences, College Jazan University, Jazan 82817, Saudi Arabia.
| | - Wafaa Fouzi Abusudah
- Clinical Nutrition Department, College of Applied Medical Sciences, Umm Al-Qura University, Makkah 24381, Saudi Arabia.
| | - Najlaa Hamed Almohmadi
- Clinical Nutrition Department, College of Applied Medical Sciences, Umm Al-Qura University, Makkah 24381, Saudi Arabia.
| | - Omayma A Eldahshan
- Department of Pharmacognosy, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt.
| | - Eman A Ahmed
- Department of Pharmacology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia 41522, Egypt.
| | - Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour 22511, Al Beheira, Egypt.
| |
Collapse
|
3
|
Al-Kuraishy HM, Al-Gareeb AI, Saad HM, Batiha GES. Benzodiazepines in Alzheimer's disease: beneficial or detrimental effects. Inflammopharmacology 2023; 31:221-230. [PMID: 36418599 DOI: 10.1007/s10787-022-01099-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 11/04/2022] [Indexed: 11/26/2022]
Abstract
Dementia is considered a clinical syndrome characterized by cognitive dysfunction and memory loss. Alzheimer's disease (AD) is the most common type of dementia. AD is linked with the turbulence of diverse neurotransmitters including gamma-aminobutyric acid (GABA). Notably, GABA in the brain and cerebrospinal fluid was reduced in AD. Thus, allosteric modulation of the GABA effect by benzodiazepines (BDZs) may improve the clinical outcomes of AD patients. Therefore, the objective of the present review was to reveal the possible role of BDZs on the pathogenesis and clinical outcomes in AD patients. Though BDZs may adversely affect cognitive functions mainly in elderly patients, herein it was postulated that BDZs may have beneficial, neutral, or detrimental effects in AD. Taken together, there is strong controversy regarding the use of BDZs and the risk for the development of AD. Therefore, experimental, preclinical and clinical studies are critical to determine the potential protective or detrimental effects of BDZs on AD neuropathology.
Collapse
Affiliation(s)
- Hayder M Al-Kuraishy
- Professor in Department of Pharmacology, Toxicology and Medicine, Medical Faculty, College of Medicine, Al-Mustansiriyah University, P.O. Box 14132, Baghdad, Iraq
| | - Ali I Al-Gareeb
- Professor in Department of Pharmacology, Toxicology and Medicine, Medical Faculty, College of Medicine, Al-Mustansiriyah University, P.O. Box 14132, Baghdad, Iraq
| | - Hebatallah M Saad
- Department of Pathology, Faculty of Veterinary Medicine, Matrouh University, Marsa Matruh, 51744, Egypt.
| | - Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour, 22511, Egypt.
| |
Collapse
|
4
|
Purves-Tyson TD, Brown AM, Weissleder C, Rothmond DA, Shannon Weickert C. Reductions in midbrain GABAergic and dopamine neuron markers are linked in schizophrenia. Mol Brain 2021; 14:96. [PMID: 34174930 PMCID: PMC8235806 DOI: 10.1186/s13041-021-00805-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 06/07/2021] [Indexed: 01/16/2023] Open
Abstract
Reductions in the GABAergic neurotransmitter system exist across multiple brain regions in schizophrenia and encompass both pre- and postsynaptic components. While reduced midbrain GABAergic inhibitory neurotransmission may contribute to the hyperdopaminergia thought to underpin psychosis in schizophrenia, molecular changes consistent with this have not been reported. We hypothesised that reduced GABA-related molecular markers would be found in the midbrain of people with schizophrenia and that these would correlate with dopaminergic molecular changes. We hypothesised that downregulation of inhibitory neuron markers would be exacerbated in schizophrenia cases with high levels of neuroinflammation. Eight GABAergic-related transcripts were measured with quantitative PCR, and glutamate decarboxylase (GAD) 65/67 and GABAA alpha 3 (α3) (GABRA3) protein were measured with immunoblotting, in post-mortem midbrain (28/28 and 28/26 control/schizophrenia cases for mRNA and protein, respectively), and analysed by both diagnosis and inflammatory subgroups (as previously defined by higher levels of four pro-inflammatory cytokine transcripts). We found reductions (21 – 44%) in mRNA encoding both presynaptic and postsynaptic proteins, vesicular GABA transporter (VGAT), GAD1, and parvalbumin (PV) mRNAs and four alpha subunits (α1, α2, α3, α5) of the GABAA receptor in people with schizophrenia compared to controls (p < 0.05). Gene expression of somatostatin (SST) was unchanged (p = 0.485). We confirmed the reduction in GAD at the protein level (34%, p < 0.05). When stratifying by inflammation, only GABRA3 mRNA exhibited more pronounced changes in high compared to low inflammatory subgroups in schizophrenia. GABRA3 protein was expressed by 98% of tyrosine hydroxylase-positive neurons and was 23% lower in schizophrenia, though this did not reach statistical significance (p > 0.05). Expression of transcripts for GABAA receptor alpha subunits 2 and 3 (GABRA2, GABRA3) were positively correlated with tyrosine hydroxylase (TH) and dopamine transporter (DAT) transcripts in schizophrenia cases (GABRA2; r > 0.630, GABRA3; r > 0.762, all p < 0.001) but not controls (GABRA2; r < − 0.200, GABRA3; r < 0.310, all p > 0.05). Taken together, our results support a profound disruption to inhibitory neurotransmission in the substantia nigra regardless of inflammatory status, which provides a potential mechanism for disinhibition of nigrostriatal dopamine neurotransmission.
Collapse
Affiliation(s)
- Tertia D Purves-Tyson
- Schizophrenia Research Laboratory, Neuroscience Research Australia, 139 Barker Street, Margarete Ainsworth Building, Level 5, Randwick, NSW, 2031, Australia. .,School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, 2052, Australia.
| | - Amelia M Brown
- Schizophrenia Research Laboratory, Neuroscience Research Australia, 139 Barker Street, Margarete Ainsworth Building, Level 5, Randwick, NSW, 2031, Australia
| | - Christin Weissleder
- Schizophrenia Research Laboratory, Neuroscience Research Australia, 139 Barker Street, Margarete Ainsworth Building, Level 5, Randwick, NSW, 2031, Australia
| | - Debora A Rothmond
- Schizophrenia Research Laboratory, Neuroscience Research Australia, 139 Barker Street, Margarete Ainsworth Building, Level 5, Randwick, NSW, 2031, Australia
| | - Cynthia Shannon Weickert
- Schizophrenia Research Laboratory, Neuroscience Research Australia, 139 Barker Street, Margarete Ainsworth Building, Level 5, Randwick, NSW, 2031, Australia. .,School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, 2052, Australia. .,Department of Neuroscience & Physiology, Upstate Medical University, Syracuse, NY, 13210, USA.
| |
Collapse
|
5
|
Bojić MG, Todorović L, Santrač A, Mian MY, Sharmin D, Cook JM, Savić MM. Vasodilatory effects of a variety of positive allosteric modulators of GABA A receptors on rat thoracic aorta. Eur J Pharmacol 2021; 899:174023. [PMID: 33722589 DOI: 10.1016/j.ejphar.2021.174023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/18/2021] [Accepted: 03/10/2021] [Indexed: 01/06/2023]
Abstract
Different subtypes of GABAA (gamma-aminobutyric acid A) receptors, through their specific regional and cellular localization, are involved in the manifestation of various functions, both at the central and peripheral levels. We hypothesized that various non-neuronal GABAA receptors are expressed on blood vessels, through which positive allosteric modulators of GABAA receptors exhibit vasodilatory effects. This study involved two parts: one to determine the presence of α1-6 subunit GABAA receptor mRNAs in the rat thoracic aorta, and the other to determine the vasoactivity of the various selective and non-selective positive GABAA receptor modulators: zolpidem (α1-selective), XHe-III-074 (α4-selective), MP-III-022 (α5-selective), DK-I-56-1 (α6-selective), SH-I-048A and diazepam (non-selective). Reverse transcription-polymerase chain reaction (RT-PCR) analysis data demonstrated for the first time the expression of α1, α2, α3, α4 and α5 subunits in the rat thoracic aorta tissue. Tissue bath assays on isolated rat aortic rings revealed significant vasodilatory effects of diazepam, SH-I-048A, XHe-III-074, MP-III-022 and DK-I-56-1, all in terms of achieved relaxations (over 50% of relative tension decrease), as well as in terms of preventive effects on phenylephrine (PE) contraction. Diazepam was the most efficient ligand in the present study, while zolpidem showed the weakest vascular effects. In addition, diazepam-induced relaxations in the presence of antagonists PK11195 or bicuculline were significantly reduced (P < 0.001 and P < 0.05, respectively) at lower concentrations of diazepam (10-7 M and 3 × 10-7 M). The present work suggests that the observed vasoactivity is due to modulation of "vascular" GABAA receptors, which after further detailed research may provide a therapeutic target.
Collapse
Affiliation(s)
- Milica Gajić Bojić
- Center for Biomedical Research, Faculty of Medicine, University of Banja Luka, 16 Save Mrkalja St, 78000, Banja Luka, Republic of Srpska, Bosnia and Herzegovina
| | - Lidija Todorović
- Laboratory for Radiobiology and Molecular Genetics, Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Anja Santrač
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, 450 Vojvode Stepe St, 11000, Belgrade, Serbia
| | - Md Yeunus Mian
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, 3210 N. Cramer St., Milwaukee, WI, 53201, USA
| | - Dishary Sharmin
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, 3210 N. Cramer St., Milwaukee, WI, 53201, USA
| | - James M Cook
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, 3210 N. Cramer St., Milwaukee, WI, 53201, USA
| | - Miroslav M Savić
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, 450 Vojvode Stepe St, 11000, Belgrade, Serbia.
| |
Collapse
|
6
|
Simeone X, Koniuszewski F, Müllegger M, Smetka A, Steudle F, Puthenkalam R, Ernst M, Scholze P. A Benzodiazepine Ligand with Improved GABA A Receptor α5-Subunit Selectivity Driven by Interactions with Loop C. Mol Pharmacol 2020; 99:39-48. [PMID: 33268553 DOI: 10.1124/molpharm.120.000067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 10/20/2020] [Indexed: 01/30/2023] Open
Abstract
The family of GABAA receptors is an important drug target group in the treatment of sleep disorders, anxiety, epileptic seizures, and many others. The most frequent GABAA receptor subtype is composed of two α-, two β-, and one γ2-subunit, whereas the nature of the α-subunit critically determines the properties of the benzodiazepine binding site of those receptors. Nearly all of the clinically relevant drugs target all GABAA receptor subtypes equally. In the past years, however, drug development research has focused on studying α5-containing GABAA receptors. Beyond the central nervous system, α5-containing GABAA receptors in airway smooth muscles are considered as an emerging target for bronchial asthma. Here, we investigated a novel compound derived from the previously described imidazobenzodiazepine SH-053-2'F-R-CH3 (SH53d-ester). Although SH53d-ester is only moderately selective for α5-subunit-containing GABAA receptors, the derivative SH53d-acid shows superior (>40-fold) affinity selectivity and is a positive modulator. Using two-electrode voltage clamp electrophysiology in Xenopus laevis oocytes and radioligand displacement assays with human embryonic kidney 293 cells, we demonstrated that an acid group as substituent on the imidazobenzodiazepine scaffold leads to large improvements of functional and binding selectivity for α5β3γ2 over other αxβ3γ2 GABAA receptors. Atom level structural studies provide hypotheses for the improved affinity to this receptor subtype. Mutational analysis confirmed the hypotheses, indicating that loop C of the GABAA receptor α-subunit is the dominant molecular determinant of drug selectivity. Thus, we characterize a promising novel α5-subunit-selective drug candidate. SIGNIFICANCE STATEMENT: In the current study we present the detailed pharmacological characterization of a novel compound derived from the previously described imidazobenzodiazepine SH-053-2'F-R-CH3. We describe its superior (>40-fold) affinity selectivity for α5-containing GABAA receptors and show atom-level structure predictions to provide hypotheses for the improved affinity to this receptor subtype. Mutational analysis confirmed the hypotheses, indicating that loop C of the GABAA receptor α-subunit is the dominant molecular determinant of drug selectivity.
Collapse
Affiliation(s)
- Xenia Simeone
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Filip Koniuszewski
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Markus Müllegger
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Andreas Smetka
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Friederike Steudle
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Roshan Puthenkalam
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Margot Ernst
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Petra Scholze
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
7
|
Mitrović JR, Divović B, Knutson DE, Đoković JB, Vulić PJ, Randjelović DV, Dobričić VD, Čalija BR, Cook JM, Savić MM, Savić SD. Nanocrystal dispersion of DK-I-56-1, a poorly soluble pyrazoloquinolinone positive modulator of α6 GABAA receptors: Formulation approach toward improved in vivo performance. Eur J Pharm Sci 2020; 152:105432. [PMID: 32565331 DOI: 10.1016/j.ejps.2020.105432] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 06/03/2020] [Accepted: 06/17/2020] [Indexed: 12/17/2022]
Abstract
DK-I-56-1 (7‑methoxy‑2-(4‑methoxy‑d3-phenyl)-2,5-dihydro-3H-pyrazolo[4,3-c]quinolin-3-one), a recently developed deuterated pyrazoloquinolinone, has been recognized as a lead candidate for treatment of various neuropsychiatric disorders. During preclinical investigation of poorly water-soluble compounds such as DK-I-56-1, the application of nanotechnology could be advantageous due to improved safety and possibly increased bioavailability of nanosized formulation. DK-I-56-1 nanosuspensions stabilized by polysorbate 80, alone or in combination with poloxamers 188 i.e. 407 or d-α-tocopheryl polyethylene glycol 1000 succinate, were prepared using a small-scale media milling device. With particle size 208.7-250.6 nm and polydispersity index <0.250, selected nanodiseprsions were stable for three weeks. Pharmacokinetic and biodistribution studies following intraperitoneal administration of three types of formulation in mice indicated high plasma DK-I-56-1 levels after solution (10,228.6 ± 1037.2 ngh/ml) and nanosuspension (6770.4 ± 770.7 ngh/ml) but not suspension administration (966.0 ± 58.1 ngh/ml). However, distribution of DK-I-56-1 after solution was heavily influenced by its composition, and brain availability of nanosuspension was superior to that of solution formulation. In spontaneous locomotor activity test, the expected hyperlocomotor effect was observed after nanosuspension administration, without compromising impact of the vehicle/excipients used. Therefore, nanonization of drug compound assembled with proper selection of stabilizers may seemingly contribute further thorough testing of DK-I-56-1 preclinical efficacy.
Collapse
Affiliation(s)
- Jelena R Mitrović
- Department of Pharmaceutical Technology and Cosmetology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia.
| | - Branka Divović
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia.
| | - Daniel E Knutson
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, 3210N. Cramer St., Milwaukee, WI 53211, USA.
| | - Jelena B Đoković
- Department of Pharmaceutical Technology and Cosmetology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia.
| | - Predrag J Vulić
- Laboratory of Crystallography, Faculty of Mining and Geology, University of Belgrade, Đušina 7, 11000 Belgrade, Serbia.
| | - Danijela V Randjelović
- Department of Microelectronic Technologies, Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoševa 12, 11000 Belgrade, Serbia.
| | - Vladimir D Dobričić
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia.
| | - Bojan R Čalija
- Department of Pharmaceutical Technology and Cosmetology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia.
| | - James M Cook
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, 3210N. Cramer St., Milwaukee, WI 53211, USA.
| | - Miroslav M Savić
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia.
| | - Snežana D Savić
- Department of Pharmaceutical Technology and Cosmetology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia.
| |
Collapse
|
8
|
Ettcheto M, Olloquequi J, Sánchez-López E, Busquets O, Cano A, Manzine PR, Beas-Zarate C, Castro-Torres RD, García ML, Bulló M, Auladell C, Folch J, Camins A. Benzodiazepines and Related Drugs as a Risk Factor in Alzheimer's Disease Dementia. Front Aging Neurosci 2020; 11:344. [PMID: 31969812 PMCID: PMC6960222 DOI: 10.3389/fnagi.2019.00344] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 11/26/2019] [Indexed: 12/21/2022] Open
Abstract
Benzodiazepines (BZDs) and Z-drugs are compounds widely prescribed in medical practice due to their anxiolytic, hypnotic, and muscle relaxant properties. Yet, their chronic use is associated with cases of abuse, dependence, and relapse in many patients. Furthermore, elderly people are susceptible to alterations in pharmacodynamics, pharmacokinetics as well as to drug interaction due to polypharmacy. These situations increase the risk for the appearance of cognitive affectations and the development of pathologies like Alzheimer's disease (AD). In the present work, there is a summary of some clinical studies that have evaluated the effect of BZDs and Z-drugs in the adult population with and without AD, focusing on the relationship between their use and the loss of cognitive function. Additionally, there is an assessment of preclinical studies focused on finding molecular proof on the pathways by which these drugs could be involved in AD pathogenesis. Moreover, available data (1990-2019) on BZD and Z-drug use among elderly patients, with and without AD, was compiled in this work. Finally, the relationship between the use of BZD and Z-drugs for the treatment of insomnia and the appearance of AD biomarkers was analyzed. Results pointed to a vicious circle that would worsen the condition of patients over time. Likewise, it put into relevance the need for close monitoring of those patients using BZDs that also suffer from AD. Consequently, future studies should focus on optimizing strategies for insomnia treatment in the elderly by using other substances like melatonin agonists, which is described to have a much more significant safety profile.
Collapse
Affiliation(s)
- Miren Ettcheto
- Departament de Farmacologia, Toxicologia i Química Terapèutica, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona, Barcelona, Spain
- Departament de Bioquímica i Biotecnologia, Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili, Reus, Spain
- Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Jordi Olloquequi
- Laboratory of Cellular and Molecular Pathology, Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Talca, Chile
| | - Elena Sánchez-López
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Unitat de Farmàcia, Tecnologia Farmacèutica i Fisico-química, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona, Barcelona, Spain
- Institute of Nanoscience and Nanotechnology (IN2UB), Universitat de Barcelona, Barcelona, Spain
| | - Oriol Busquets
- Departament de Farmacologia, Toxicologia i Química Terapèutica, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona, Barcelona, Spain
- Departament de Bioquímica i Biotecnologia, Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili, Reus, Spain
- Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Amanda Cano
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Unitat de Farmàcia, Tecnologia Farmacèutica i Fisico-química, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona, Barcelona, Spain
- Institute of Nanoscience and Nanotechnology (IN2UB), Universitat de Barcelona, Barcelona, Spain
| | | | - Carlos Beas-Zarate
- Laboratorio de Regeneración y Desarrollo Neural, Departamento de Biología Celular y Molecular, Instituto de Neurobiología, CUCBA, Guadalajara, Mexico
| | - Rubén D. Castro-Torres
- Laboratorio de Regeneración y Desarrollo Neural, Departamento de Biología Celular y Molecular, Instituto de Neurobiología, CUCBA, Guadalajara, Mexico
| | - Maria Luisa García
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Unitat de Farmàcia, Tecnologia Farmacèutica i Fisico-química, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona, Barcelona, Spain
- Institute of Nanoscience and Nanotechnology (IN2UB), Universitat de Barcelona, Barcelona, Spain
| | - Mónica Bulló
- Departament de Bioquímica i Biotecnologia, Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili, Reus, Spain
- Institut d'Investigació Sanitària Pere Virgili (IISPV), Reus, Spain
- Centro de Investigación Biomédica en Red Fisiopatologia de la Obesidad y la Nutrición (CIBEROBN), Institut de Salud Carlos III, Madrid, Spain
| | - Carme Auladell
- Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Departament de Biologia Cellular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Jaume Folch
- Departament de Bioquímica i Biotecnologia, Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili, Reus, Spain
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Antonio Camins
- Departament de Farmacologia, Toxicologia i Química Terapèutica, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona, Barcelona, Spain
- Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Laboratory of Cellular and Molecular Pathology, Facultad de Ciencias de la Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Talca, Chile
| |
Collapse
|
9
|
Maramai S, Benchekroun M, Ward SE, Atack JR. Subtype Selective γ-Aminobutyric Acid Type A Receptor (GABAAR) Modulators Acting at the Benzodiazepine Binding Site: An Update. J Med Chem 2019; 63:3425-3446. [DOI: 10.1021/acs.jmedchem.9b01312] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Samuele Maramai
- Sussex Drug Discovery Centre, University of Sussex, Brighton BN1 9QJ, U.K
| | - Mohamed Benchekroun
- Sussex Drug Discovery Centre, University of Sussex, Brighton BN1 9QJ, U.K
- Équipe de Chimie Moléculaire, Laboratoire de Génomique Bioinformatique et Chimie Moléculaire, GBCM, EA7528, Conservatoire National des Arts et Métiers, 2 rue Conté, 75003 Paris, France
| | - Simon E. Ward
- Medicines Discovery Institute, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K
| | - John R. Atack
- Medicines Discovery Institute, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K
| |
Collapse
|
10
|
Neumann E, Rudolph U, Knutson DE, Li G, Cook JM, Hentschke H, Antkowiak B, Drexler B. Zolpidem Activation of Alpha 1-Containing GABA A Receptors Selectively Inhibits High Frequency Action Potential Firing of Cortical Neurons. Front Pharmacol 2019; 9:1523. [PMID: 30687091 PMCID: PMC6333667 DOI: 10.3389/fphar.2018.01523] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 12/12/2018] [Indexed: 11/13/2022] Open
Abstract
Introduction: High frequency neuronal activity in the cerebral cortex can be induced by noxious stimulation during surgery, brain injury or poisoning. In this scenario, it is essential to block cortical hyperactivity to protect the brain against damage, e.g., by using drugs that act as positive allosteric modulators at GABAA receptors. Yet, cortical neurons express multiple, functionally distinct GABAA receptor subtypes. Currently there is a lack of knowledge which GABAA receptor subtypes would be a good pharmacological target to reduce extensive cortical activity. Methods: Spontaneous action potential activity was monitored by performing extracellular recordings from organotypic neocortical slice cultures of wild type and GABAAR-α1(H101R) mutant mice. Phases of high neuronal activity were characterized using peri-event time histograms. Drug effects on within-up state firing rates were quantified via Hedges' g. Results: We quantified the effects of zolpidem, a positive modulator of GABAA receptors harboring α1-subunits, and the experimental benzodiazepine SH-053-2'F-S-CH3, which preferably acts at α2/3/5- but spares α1-subunits. Both agents decreased spontaneous action potential activity but altered the firing patterns in different ways. Zolpidem reduced action potential firing during highly active network states. This action was abolished by flumazenil, suggesting that it was mediated by benzodiazepine-sensitive GABAA receptors. SH-053-2'F-S-CH3 also attenuated neuronal activity, but unlike zolpidem, failed to reduce high frequency firing. To confirm that zolpidem actions were indeed mediated via α1-dependent actions, it was evaluated in slices from wild type and α(H101R) knock-in mice. Inhibition of high frequency action potential firing was observed in slices from wild type but not mutant mice. Conclusion: Our results suggest that during episodes of scarce and high neuronal activity action potential firing of cortical neurons is controlled by different GABAA receptor subtypes. Exaggerated firing of cortical neurons is reduced by positive modulation of α1-, but not α2/3/5-subunit containing GABAA receptors.
Collapse
Affiliation(s)
- Elena Neumann
- Experimental Anesthesiology Section, Department of Anesthesiology and Intensive Care, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Uwe Rudolph
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Daniel E Knutson
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - Guanguan Li
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - James M Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - Harald Hentschke
- Experimental Anesthesiology Section, Department of Anesthesiology and Intensive Care, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Bernd Antkowiak
- Experimental Anesthesiology Section, Department of Anesthesiology and Intensive Care, Eberhard Karls Universität Tübingen, Tübingen, Germany.,Werner Reichardt Center for Integrative Neuroscience, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Berthold Drexler
- Experimental Anesthesiology Section, Department of Anesthesiology and Intensive Care, Eberhard Karls Universität Tübingen, Tübingen, Germany
| |
Collapse
|
11
|
Sieghart W, Savić MM. International Union of Basic and Clinical Pharmacology. CVI: GABAA Receptor Subtype- and Function-selective Ligands: Key Issues in Translation to Humans. Pharmacol Rev 2018; 70:836-878. [DOI: 10.1124/pr.117.014449] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
|
12
|
Szodorai E, Bampali K, Romanov RA, Kasper S, Hökfelt T, Ernst M, Lubec G, Harkany T. Diversity matters: combinatorial information coding by GABA A receptor subunits during spatial learning and its allosteric modulation. Cell Signal 2018; 50:142-159. [DOI: 10.1016/j.cellsig.2018.07.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 07/08/2018] [Accepted: 07/09/2018] [Indexed: 01/11/2023]
|
13
|
Elgarf A, Siebert DCB, Steudle F, Draxler A, Li G, Huang S, Cook JM, Ernst M, Scholze P. Different Benzodiazepines Bind with Distinct Binding Modes to GABA A Receptors. ACS Chem Biol 2018; 13:2033-2039. [PMID: 29767950 PMCID: PMC6102643 DOI: 10.1021/acschembio.8b00144] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/16/2018] [Indexed: 01/20/2023]
Abstract
Benzodiazepines are clinically relevant drugs that bind to GABAA neurotransmitter receptors at the α+/γ2- interfaces and thereby enhance GABA-induced chloride ion flux leading to neuronal hyperpolarization. However, the structural basis of benzodiazepine interactions with their high-affinity site at GABAA receptors is controversially debated in the literature, and in silico studies led to discrepant binding mode hypotheses. In this study, computational docking of diazepam into α+/γ2- homology models suggested that a chiral methyl group, which is known to promote preferred binding to α5-containing GABAA receptors (position 3 of the seven-membered diazepine ring), could possibly provide experimental evidence that supports or contradicts the proposed binding modes. Thus, we investigated three pairs of R and S isomers of structurally different chemotypes, namely, diazepam, imidazobenzodiazepine, and triazolam derivatives. We used radioligand displacement studies as well as two-electrode voltage clamp electrophysiology in α1β3γ2-, α2β3γ2-, α3β3γ2-, and α5β3γ2-containing GABAA receptors to determine the ligand binding and functional activity of the three chemotypes. Interestingly, both imidazobenzodiazepine isomers displayed comparable binding affinities, while for the other two chemotypes, a discrepancy in binding affinities of the different isomers was observed. Specifically, the R isomers displayed a loss of binding, whereas the S isomers remained active. These findings are in accordance with the results of our in silico studies suggesting the usage of a different binding mode of imidazobenzodiazepines compared to those of the other two tested chemotypes. Hence, we conclude that different chemically related benzodiazepine ligands interact via distinct binding modes rather than by using a common binding mode.
Collapse
Affiliation(s)
- Alshaimaa
A. Elgarf
- Department
of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria
- Department
of Pharmacology and Therapeutics, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | | | - Friederike Steudle
- Department
of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria
- Department
of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria
| | - Angelika Draxler
- Department
of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria
| | - Guanguan Li
- Department
of Chemistry and Biochemistry, University
of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, United States
| | - Shengming Huang
- Department
of Chemistry and Biochemistry, University
of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, United States
| | - James M. Cook
- Department
of Chemistry and Biochemistry, University
of Wisconsin—Milwaukee, Milwaukee, Wisconsin 53211, United States
| | - Margot Ernst
- Department
of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria
| | - Petra Scholze
- Department
of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria
| |
Collapse
|
14
|
Batinić B, Stanković T, Stephen MR, Kodali R, Tiruveedhula VV, Li G, Scholze P, Marković BD, Obradović AL, Ernst M, Cook JM, Savić MM. Attaining in vivo selectivity of positive modulation of α3βγ2 GABA A receptors in rats: A hard task! Eur Neuropsychopharmacol 2018; 28:903-914. [PMID: 29891214 DOI: 10.1016/j.euroneuro.2018.05.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 04/10/2018] [Accepted: 05/21/2018] [Indexed: 12/22/2022]
Abstract
It is unclear whether GABAA receptors (GABAARs) that contain the α3-subunit are substantially involved in the anxiolytic effects of benzodiazepines (BDZs). In the present study, we tested YT-III-31, a newer BDZ ligand with functional preference for α3βγ2 GABAARs, in two paradigms of unconditioned anxiety, the open field and elevated plus maze in rats. The effective dose of YT-III-31 (2 mg/kg) displayed a clear anxiolytic-like profile, unhampered by sedative action, in both tests. At a higher dose (10 mg/kg), YT-III-31 induced ataxia in the rotarod and sedation in spontaneous locomotor activity test. The latter effect was preventable by flumazenil and βCCt, the non-selective and α1βγ2 GABAAR affinity-selective antagonist, respectively, demonstrating that sedative properties of YT-III-31, when attained, are mediated by the α1γ2 site. To elucidate the receptor substrate of subtle behavioral differences between YT-III-31 and diazepam, we approximated in vivo receptor potentiation for both ligands, based on estimated unbound concentrations in rat brains. Far different from diazepam, YT-III-31 has significantly lower affinity for the α1γ2 over other BDZ-sensitive sites, and at lower doses (1-2 mg/kg) was devoid of potentiation at α1βγ2 GABAARs. The approximation approach revealed a modest selectivity of YT-III-31 for α3γ2- in comparison to α2γ2 and α5γ2 binding sites, suggesting that its anxiolytic-like activity may not necessarily or predominantly reflect potentiation at α3βγ2 GABAARs. Nonetheless, as the anxiolytic effects are achievable at a dose devoid of any sedative potential, and having favorable safety (cytotoxicity) and metabolic stability profile, YT-III-31 represents a valuable candidate for further translational research.
Collapse
Affiliation(s)
- Bojan Batinić
- Department of Physiology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Tamara Stanković
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Michael Rajesh Stephen
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
| | - Revathi Kodali
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
| | - Veera V Tiruveedhula
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
| | - Guanguan Li
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
| | - Petra Scholze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Bojan D Marković
- Department of Pharmaceutical Pharmacy, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Aleksandar Lj Obradović
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Margot Ernst
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - James M Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
| | - Miroslav M Savić
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia.
| |
Collapse
|
15
|
Li G, Stephen MR, Kodali R, Zahn NM, Poe MM, Tiruveedhula VVNPB, Huber AT, Schussman MK, Qualmann K, Panhans CM, Raddatz NJ, Baker DA, Prevot TD, Banasr M, Sibille E, Arnold LA, Cook JM. Synthesis of chiral GABA A receptor subtype selective ligands as potential agents to treat schizophrenia as well as depression. ARKIVOC 2018; 2018:158-182. [PMID: 32774192 PMCID: PMC7413308 DOI: 10.24820/ark.5550190.p010.460] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
A series of novel imidazobenzodiazepine analogs of the lead chiral ligand SH-053-2'F-S-CH3 (2), an α2/α3/α5 (Bz)GABA (A)ergic receptor subtype selective ligand, which reversed PCP-induced prepulse inhibition (PPI) of acoustic startle, were synthesized. These chiral (S)-CH3 ligands are targeted for the treatment of schizophrenia and depression. These new ligands were designed by modifying the liable ester functionality in 2 to improve the metabolic stability, cytotoxicity, and activity as compared to 2. Based on the data to date, the most promising ligands are the N-cyclopropyl amide GL-I-55 (8c) and the methyl bioisostere GL-I-65 (9a). The in vitro metabolic stability, cytotoxicity and in vivo locomotor effects are described in this report. Based on these results, 8c and 9a are the most promising for further in vivo pharmacology.
Collapse
Affiliation(s)
- Guanguan Li
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Michael R Stephen
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Revathi Kodali
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Nicolas M Zahn
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Michael M Poe
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - V V N Phani Babu Tiruveedhula
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Alec T Huber
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Melissa K Schussman
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Krista Qualmann
- Department of Biomedical Science, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Cristina M Panhans
- Department of Biomedical Science, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Nicholas J Raddatz
- Department of Biomedical Science, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - David A Baker
- Department of Biomedical Science, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Thomas D Prevot
- Campbell Family Mental Health Research Institute of CAMH, Toronto, Canada
| | - Mounira Banasr
- Campbell Family Mental Health Research Institute of CAMH, Toronto, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Canada
- Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Etienne Sibille
- Campbell Family Mental Health Research Institute of CAMH, Toronto, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Canada
- Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Leggy A Arnold
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - James M Cook
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| |
Collapse
|
16
|
Knutson DE, Kodali R, Divović B, Treven M, Stephen MR, Zahn NM, Dobričić V, Huber AT, Meirelles MA, Verma RS, Wimmer L, Witzigmann C, Arnold LA, Chiou LC, Ernst M, Mihovilovic MD, Savić MM, Sieghart W, Cook JM. Design and Synthesis of Novel Deuterated Ligands Functionally Selective for the γ-Aminobutyric Acid Type A Receptor (GABA AR) α6 Subtype with Improved Metabolic Stability and Enhanced Bioavailability. J Med Chem 2018; 61:2422-2446. [PMID: 29481759 DOI: 10.1021/acs.jmedchem.7b01664] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Recent reports indicate that α6β2/3γ2 GABAAR selective ligands may be important for the treatment of trigeminal activation-related pain and neuropsychiatric disorders with sensori-motor gating deficits. Based on 3 functionally α6β2/3γ2 GABAAR selective pyrazoloquinolinones, 42 novel analogs were synthesized, and their in vitro metabolic stability and cytotoxicity as well as their in vivo pharmacokinetics, basic behavioral pharmacology, and effects on locomotion were investigated. Incorporation of deuterium into the methoxy substituents of the ligands increased their duration of action via improved metabolic stability and bioavailability, while their selectivity for the GABAAR α6 subtype was retained. 8b was identified as the lead compound with a substantially improved pharmacokinetic profile. The ligands allosterically modulated diazepam insensitive α6β2/3γ2 GABAARs and were functionally silent at diazepam sensitive α1β2/3γ2 GABAARs, thus no sedation was detected. In addition, these analogs were not cytotoxic, which render them interesting candidates for treatment of CNS disorders mediated by GABAAR α6β2/3γ2 subtypes.
Collapse
Affiliation(s)
- Daniel E Knutson
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery , University of Wisconsin-Milwaukee , 3210 N. Cramer St. , Milwaukee , Wisconsin 53211 , United States
| | - Revathi Kodali
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery , University of Wisconsin-Milwaukee , 3210 N. Cramer St. , Milwaukee , Wisconsin 53211 , United States
| | - Branka Divović
- Department of Pharmacology, Faculty of Pharmacy , University of Belgrade , Vojvode Stepe 450 , 11221 Belgrade , Serbia
| | - Marco Treven
- Department of Molecular Neurosciences, Center for Brain Research , Medical University of Vienna , Spitalgasse 4 , A-1090 Vienna , Austria
| | - Michael R Stephen
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery , University of Wisconsin-Milwaukee , 3210 N. Cramer St. , Milwaukee , Wisconsin 53211 , United States
| | - Nicolas M Zahn
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery , University of Wisconsin-Milwaukee , 3210 N. Cramer St. , Milwaukee , Wisconsin 53211 , United States
| | - Vladimir Dobričić
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy , University of Belgrade , Vojvode Stepe 450 , 11221 Belgrade , Serbia
| | - Alec T Huber
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery , University of Wisconsin-Milwaukee , 3210 N. Cramer St. , Milwaukee , Wisconsin 53211 , United States
| | - Matheus A Meirelles
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery , University of Wisconsin-Milwaukee , 3210 N. Cramer St. , Milwaukee , Wisconsin 53211 , United States
| | - Ranjit S Verma
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery , University of Wisconsin-Milwaukee , 3210 N. Cramer St. , Milwaukee , Wisconsin 53211 , United States
| | - Laurin Wimmer
- TU Wien-Institute of Applied Synthetic Chemistry , Getreidemarkt 9/163 , A-1060 Vienna , Austria
| | - Christopher Witzigmann
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery , University of Wisconsin-Milwaukee , 3210 N. Cramer St. , Milwaukee , Wisconsin 53211 , United States
| | - Leggy A Arnold
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery , University of Wisconsin-Milwaukee , 3210 N. Cramer St. , Milwaukee , Wisconsin 53211 , United States
| | - Lih-Chu Chiou
- Graduate Institute of Acupuncture Science , China Medical University , Taichung 40402 , Taiwan
| | - Margot Ernst
- Department of Molecular Neurosciences, Center for Brain Research , Medical University of Vienna , Spitalgasse 4 , A-1090 Vienna , Austria
| | - Marko D Mihovilovic
- TU Wien-Institute of Applied Synthetic Chemistry , Getreidemarkt 9/163 , A-1060 Vienna , Austria
| | - Miroslav M Savić
- Department of Pharmacology, Faculty of Pharmacy , University of Belgrade , Vojvode Stepe 450 , 11221 Belgrade , Serbia
| | - Werner Sieghart
- Department of Molecular Neurosciences, Center for Brain Research , Medical University of Vienna , Spitalgasse 4 , A-1090 Vienna , Austria
| | - James M Cook
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery , University of Wisconsin-Milwaukee , 3210 N. Cramer St. , Milwaukee , Wisconsin 53211 , United States
| |
Collapse
|
17
|
Witkin JM, Cerne R, Wakulchik M, S J, Gleason SD, Jones TM, Li G, Arnold LA, Li JX, Schkeryantz JM, Methuku KR, Cook JM, Poe MM. Further evaluation of the potential anxiolytic activity of imidazo[1,5-a][1,4]diazepin agents selective for α2/3-containing GABA A receptors. Pharmacol Biochem Behav 2017; 157:35-40. [PMID: 28442369 PMCID: PMC5519285 DOI: 10.1016/j.pbb.2017.04.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 04/20/2017] [Accepted: 04/21/2017] [Indexed: 11/24/2022]
Abstract
Positive allosteric modulators of GABAA receptors transduce a host of beneficial effects including anxiolytic actions. We have recently shown that bioavailability and anxiolytic-like activity can be improved by eliminating the ester functionality in imidazo[1,5-a][1,4]diazepines. In the present series of experiments, we further substantiate the value of heterocyle replacement of the ester for potential treatment of anxiety. None of three esters was active in a Vogel conflict test in rats that detects anxiolytic drugs like diazepam. Compounds 7 and 8, ester bioisosters, were selective for alpha 2 and 3 over alpha 1-containing GABAA receptors but also had modest efficacy at GABAA alpha 5-containing receptors. Compound 7 was efficacious and potent in this anxiolytic-detecting assay without affecting non-punished responding. The efficacies of the esters and of compound 7 were predicted from their efficacies as anticonvulsants against the GABAA antagonist pentylenetetrazole (PTZ). In contrast, the related structural analog, compound 8, did not produce anxiolytic-like effects in rats despite anticonvulsant efficacy. These data thus support the following conclusions: 1) ancillary pharmacological actions of compound 8 might be responsible for its lack of anxiolytic-like efficacy despite its efficacy as an anticonvulsant 2) esters of imidazo[1,5-a][1,4]diazepines do not demonstrate anxiolytic-like effects in rats due to their low bioavailability and 3) replacement of the ester function with suitable heterocycles markedly improves bioavailability and engenders molecules with the opportunity to have potent and efficacious effects in vivo that correspond to human anxiolytic actions.
Collapse
Affiliation(s)
- J M Witkin
- Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN, United States.
| | - R Cerne
- Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN, United States
| | - M Wakulchik
- Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN, United States
| | - J S
- Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN, United States
| | - S D Gleason
- Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN, United States
| | - T M Jones
- Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN, United States
| | - G Li
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - L A Arnold
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - J-X Li
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - J M Schkeryantz
- Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN, United States
| | - K R Methuku
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - J M Cook
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - M M Poe
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| |
Collapse
|
18
|
Piantadosi SC, French BJ, Poe MM, Timić T, Marković BD, Pabba M, Seney ML, Oh H, Orser BA, Savić MM, Cook JM, Sibille E. Sex-Dependent Anti-Stress Effect of an α5 Subunit Containing GABA A Receptor Positive Allosteric Modulator. Front Pharmacol 2016; 7:446. [PMID: 27920723 PMCID: PMC5118774 DOI: 10.3389/fphar.2016.00446] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 11/08/2016] [Indexed: 12/21/2022] Open
Abstract
Rationale: Current first-line treatments for stress-related disorders such as major depressive disorder (MDD) act on monoaminergic systems and take weeks to achieve a therapeutic effect with poor response and low remission rates. Recent research has implicated the GABAergic system in the pathophysiology of depression, including deficits in interneurons targeting the dendritic compartment of cortical pyramidal cells. Objectives: The present study evaluates whether SH-053-2’F-R-CH3 (denoted “α5-PAM”), a positive allosteric modulator selective for α5-subunit containing GABAA receptors found predominantly on cortical pyramidal cell dendrites, has anti-stress effects. Methods: Female and male C57BL6/J mice were exposed to unpredictable chronic mild stress (UCMS) and treated with α5-PAM acutely (30 min prior to assessing behavior) or chronically before being assessed behaviorally. Results: Acute and chronic α5-PAM treatments produce a pattern of decreased stress-induced behaviors (denoted as “behavioral emotionality”) across various tests in female, but not in male mice. Behavioral Z-scores calculated across a panel of tests designed to best model the range and heterogeneity of human symptomatology confirmed that acute and chronic α5-PAM treatments consistently produce significant decreases in behavioral emotionality in several independent cohorts of females. The behavioral responses to α5-PAM could not be completely accounted for by differences in drug brain disposition between female and male mice. In mice exposed to UCMS, expression of the Gabra5 gene was increased in the frontal cortex after acute treatment and in the hippocampus after chronic treatment with α5-PAM in females only, and these expression changes correlated with behavioral emotionality. Conclusion: We showed that acute and chronic positive modulation of α5 subunit-containing GABAA receptors elicit anti-stress effects in a sex-dependent manner, suggesting novel therapeutic modalities.
Collapse
Affiliation(s)
- Sean C Piantadosi
- Center for Neuroscience, University of PittsburghPittsburgh, PA, USA; Department of Psychiatry, University of PittsburghPittsburgh, PA, USA
| | - Beverly J French
- Department of Psychiatry, University of Pittsburgh Pittsburgh, PA, USA
| | - Michael M Poe
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee Milwaukee, WI, USA
| | - Tamara Timić
- Department of Pharmacology, University of Belgrade Belgrade, Serbia
| | - Bojan D Marković
- Department of Pharmaceutical Chemistry, University of Belgrade Belgrade, Serbia
| | - Mohan Pabba
- Neurobiology of Depression and Aging, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health Toronto, ON, Canada
| | - Marianne L Seney
- Department of Psychiatry, University of Pittsburgh Pittsburgh, PA, USA
| | - Hyunjung Oh
- Center for Neuroscience, University of PittsburghPittsburgh, PA, USA; Department of Psychiatry, University of PittsburghPittsburgh, PA, USA; Neurobiology of Depression and Aging, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental HealthToronto, ON, Canada
| | - Beverley A Orser
- Department of Anesthesia-Department of Physiology, University of Toronto Toronto, ON, Canada
| | - Miroslav M Savić
- Department of Pharmacology, University of Belgrade Belgrade, Serbia
| | - James M Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee Milwaukee, WI, USA
| | - Etienne Sibille
- Center for Neuroscience, University of PittsburghPittsburgh, PA, USA; Department of Psychiatry, University of PittsburghPittsburgh, PA, USA; Neurobiology of Depression and Aging, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental HealthToronto, ON, Canada; Department of Psychiatry- Department of Pharmacology and Toxicology, University of TorontoToronto, ON, Canada
| |
Collapse
|
19
|
Townsend M, Whyment A, Walczak JS, Jeggo R, van den Top M, Flood DG, Leventhal L, Patzke H, Koenig G. α7-nAChR agonist enhances neural plasticity in the hippocampus via a GABAergic circuit. J Neurophysiol 2016; 116:2663-2675. [PMID: 27655963 DOI: 10.1152/jn.00243.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 09/18/2016] [Indexed: 11/22/2022] Open
Abstract
Agonists of the α7-nicotinic acetylcholine receptor (α7-nAChR) have entered clinical trials as procognitive agents for treating schizophrenia and Alzheimer's disease. The most advanced compounds are orthosteric agonists, which occupy the ligand binding site. At the molecular level, agonist activation of α7-nAChR is reasonably well understood. However, the consequences of activating α7-nAChRs on neural circuits underlying cognition remain elusive. Here we report that an α7-nAChR agonist (FRM-17848) enhances long-term potentiation (LTP) in rat septo-hippocampal slices far below the cellular EC50 but at a concentration that coincides with multiple functional outcome measures as we reported in Stoiljkovic M, Leventhal L, Chen A, Chen T, Driscoll R, Flood D, Hodgdon H, Hurst R, Nagy D, Piser T, Tang C, Townsend M, Tu Z, Bertrand D, Koenig G, Hajós M. Biochem Pharmacol 97: 576-589, 2015. In this same concentration range, we observed a significant increase in spontaneous γ-aminobutyric acid (GABA) inhibitory postsynaptic currents and a moderate suppression of excitability in whole cell recordings from rat CA1 pyramidal neurons. This modulation of GABAergic activity is necessary for the LTP-enhancing effects of FRM-17848, since inhibiting GABAA α5-subunit-containing receptors fully reversed the effects of the α7-nAChR agonist. These data suggest that α7-nAChR agonists may increase synaptic plasticity in hippocampal slices, at least in part, through a circuit-level enhancement of a specific subtype of GABAergic receptor.
Collapse
Affiliation(s)
| | | | | | - Ross Jeggo
- Cerebrasol, Ltd., Montreal, Quebec City, Canada
| | | | | | - Liza Leventhal
- FORUM Pharmaceuticals, Inc., Waltham, Massachusetts; and
| | - Holger Patzke
- FORUM Pharmaceuticals, Inc., Waltham, Massachusetts; and
| | - Gerhard Koenig
- FORUM Pharmaceuticals, Inc., Waltham, Massachusetts; and
| |
Collapse
|
20
|
Stamenić TT, Poe MM, Rehman S, Santrač A, Divović B, Scholze P, Ernst M, Cook JM, Savić MM. Ester to amide substitution improves selectivity, efficacy and kinetic behavior of a benzodiazepine positive modulator of GABA A receptors containing the α5 subunit. Eur J Pharmacol 2016; 791:433-443. [PMID: 27639297 DOI: 10.1016/j.ejphar.2016.09.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 09/07/2016] [Accepted: 09/07/2016] [Indexed: 12/22/2022]
Abstract
We have synthesized and characterized MP-III-022 ((R)-8-ethynyl-6-(2-fluorophenyl)-N,4-dimethyl-4H-benzo[f]imidazo[1,5-a][1,4]diazepine-3-carboxamide) in vitro and in vivo as a binding- and efficacy-selective positive allosteric modulator of GABAA receptors containing the α5 subunit (α5GABAARs). By approximation of the electrophysiological responses which the estimated free rat brain concentrations can induce, we demonstrated that convenient systemic administration of MP-III-022 in the dose range 1-10mg/kg may result in a selective potentiation, over a wide range from mild to moderate to strong, of α5βγ2 GABAA receptors. For eliciting a comparable range of potentiation, the widely studied parent ligand SH-053-2'F-R-CH3 containing an ester moiety needs to be administered over a much wider dose range (10-200mg/kg), but at the price of activating non-α5 GABAARs as well as the desired α5GABAARs at the highest dose. At the dose of 10mg/kg, which elicits a strong positive modulation of α5GABAARs, MP-III-022 caused mild, but significant muscle relaxation, while at doses 1-10mg/kg was devoid of ataxia, sedation or an influence on the anxiety level, characteristic for non-selective benzodiazepines. As an amide compound with improved stability and kinetic properties, MP-III-022 may represent an optimized tool to study the influence of α5GABAARs on the neuronal pathways related to CNS disorders such as schizophrenia, Alzheimer's disease, Down syndrome or autism.
Collapse
Affiliation(s)
- Tamara Timić Stamenić
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Michael M Poe
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, Wisconsin 53201, USA
| | - Sabah Rehman
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Anja Santrač
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Branka Divović
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Petra Scholze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Margot Ernst
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - James M Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, Wisconsin 53201, USA
| | - Miroslav M Savić
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia.
| |
Collapse
|
21
|
A Review of the Updated Pharmacophore for the Alpha 5 GABA(A) Benzodiazepine Receptor Model. INTERNATIONAL JOURNAL OF MEDICINAL CHEMISTRY 2015; 2015:430248. [PMID: 26682068 PMCID: PMC4657098 DOI: 10.1155/2015/430248] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 06/16/2015] [Accepted: 07/02/2015] [Indexed: 12/22/2022]
Abstract
An updated model of the GABA(A) benzodiazepine receptor pharmacophore of the α5-BzR/GABA(A) subtype has been constructed prompted by the synthesis of subtype selective ligands in light of the recent developments in both ligand synthesis, behavioral studies, and molecular modeling studies of the binding site itself. A number of BzR/GABA(A) α5 subtype selective compounds were synthesized, notably α5-subtype selective inverse agonist PWZ-029 (1) which is active in enhancing cognition in both rodents and primates. In addition, a chiral positive allosteric modulator (PAM), SH-053-2′F-R-CH3 (2), has been shown to reverse the deleterious effects in the MAM-model of schizophrenia as well as alleviate constriction in airway smooth muscle. Presented here is an updated model of the pharmacophore for α5β2γ2 Bz/GABA(A) receptors, including a rendering of PWZ-029 docked within the α5-binding pocket showing specific interactions of the molecule with the receptor. Differences in the included volume as compared to α1β2γ2, α2β2γ2, and α3β2γ2 will be illustrated for clarity. These new models enhance the ability to understand structural characteristics of ligands which act as agonists, antagonists, or inverse agonists at the Bz BS of GABA(A) receptors.
Collapse
|
22
|
Richetto J, Labouesse MA, Poe MM, Cook JM, Grace AA, Riva MA, Meyer U. Behavioral effects of the benzodiazepine-positive allosteric modulator SH-053-2'F-S-CH₃ in an immune-mediated neurodevelopmental disruption model. Int J Neuropsychopharmacol 2015; 18:pyu055. [PMID: 25636893 PMCID: PMC4360215 DOI: 10.1093/ijnp/pyu055] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Impaired γ-aminobutyric acid (GABA) signaling may contribute to the emergence of cognitive deficits and subcortical dopaminergic hyperactivity in patients with schizophrenia and related psychotic disorders. Against this background, it has been proposed that pharmacological interventions targeting GABAergic dysfunctions may prove useful in correcting such cognitive impairments and dopaminergic imbalances. METHODS Here, we explored possible beneficial effects of the benzodiazepine-positive allosteric modulator SH-053-2'F-S-CH₃, with partial selectivity at the α2, α3, and α5 subunits of the GABAA receptor in an immune-mediated neurodevelopmental disruption model. The model is based on prenatal administration of the viral mimetic polyriboinosinic-polyribocytidilic acid [poly(I:C)] in mice, which is known to capture various GABAergic, dopamine-related, and cognitive abnormalities implicated in schizophrenia and related disorders. RESULTS Real-time polymerase chain reaction analyses confirmed the expected alterations in GABAA receptor α subunit gene expression in the medial prefrontal cortices and ventral hippocampi of adult poly(I:C) offspring relative to control offspring. Systemic administration of SH-053-2'F-S-CH₃ failed to normalize the poly(I:C)-induced deficits in working memory and social interaction, but instead impaired performance in these cognitive and behavioral domains both in control and poly(I:C) offspring. In contrast, SH-053-2'F-S-CH₃ was highly effective in mitigating the poly(I:C)-induced amphetamine hypersensitivity phenotype without causing side effects in control offspring. CONCLUSIONS Our preclinical data suggest that benzodiazepine-like positive allosteric modulators with activity at the α2, α3, and α5 subunits of the GABAA receptor may be particularly useful in correcting pathological overactivity of the dopaminergic system, but they may be ineffective in targeting multiple pathological domains that involve the co-existence of psychotic, social, and cognitive dysfunctions.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Urs Meyer
- Center of Neuropharmacology, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy (Drs Richetto and Riva); Physiology and Behavior Laboratory, ETH Zurich, Schorenstrasse 16, 8603 Schwerzenbach, Switzerland (Drs Labouesse and Meyer); Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI (Drs Poe and Cook); Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA (Dr Grace); Center of Excellence on Neurodegenerative Diseases, Università degli Studi di Milano, Milan, Italy (Dr Riva).
| |
Collapse
|
23
|
Bonoldi I, Howes OD. Presynaptic dopaminergic function: implications for understanding treatment response in psychosis. CNS Drugs 2014; 28:649-63. [PMID: 24919790 DOI: 10.1007/s40263-014-0177-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
All current antipsychotic drugs block dopamine (DA) receptors, but the nature of the DA dysfunction in schizophrenia has not been clear. However, consistent evidence now shows that presynaptic dopaminergic function is altered in schizophrenia, specifically in terms of increased DA synthesis capacity, baseline synaptic DA levels, and DA release. Furthermore, presynaptic dopaminergic function is already elevated in prodromal patients who later developed the disorder. Currently available antipsychotics act on postsynaptic receptors, not targeting presynaptic DA abnormalities. This has implications for understanding response and developing new treatments. The lack of normalization of the abnormal presynaptic function could explain why discontinuation is likely to lead to relapse, because the major dopaminergic function persists, meaning that once treatment stops there is nothing to oppose the dysregulated dopamine function reinstating symptoms. Furthermore, it suggests that drugs that target presynaptic dopaminergic function may constitute new treatment possibilities for schizophrenic patients, in particular, for those in whom antipsychotics are poorly effective. In addition, the longitudinal changes with the onset of psychosis indicate the potential to target a defined dynamic neurochemical abnormality to prevent the onset of psychosis.
Collapse
Affiliation(s)
- I Bonoldi
- Department of Psychosis Studies, Institute of Psychiatry, King's College of London, De Crespigny Park 16, London, SE5 8AF, UK,
| | | |
Collapse
|
24
|
Ennaceur A. Tests of unconditioned anxiety - pitfalls and disappointments. Physiol Behav 2014; 135:55-71. [PMID: 24910138 DOI: 10.1016/j.physbeh.2014.05.032] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 04/21/2014] [Accepted: 05/28/2014] [Indexed: 02/05/2023]
Abstract
The plus-maze, the light-dark box and the open-field are the main current tests of unconditioned anxiety for mice and rats. Despite their disappointing achievements, they remain as popular as ever and seem to play an important role in an ever-growing demand for behavioral phenotyping and drug screening. Numerous reviews have repeatedly reported their lack of consistency and reliability but they failed to address the core question of whether these tests do provide unequivocal measures of fear-induced anxiety, that these measurements are not confused with measures of fear-induced avoidance or natural preference responses - i.e. discriminant validity. In the present report, I examined numerous issues that undermine the validity of the current tests, and I highlighted various flaws in the aspects of these tests and the methodologies pursued. This report concludes that the evidence in support of the validity of the plus-maze, the light/dark box and the open-field as anxiety tests is poor and methodologically questionable.
Collapse
Affiliation(s)
- A Ennaceur
- University of Sunderland, Department of Pharmacy, Wharncliffe Street, Sunderland SR1 3SD, UK.
| |
Collapse
|
25
|
Obradović AL, Joksimović S, Poe MM, Ramerstorfer J, Varagic Z, Namjoshi O, Batinić B, Radulović T, Marković B, Roth BL, Sieghart W, Cook JM, Savić MM. Sh-I-048A, an in vitro non-selective super-agonist at the benzodiazepine site of GABAA receptors: the approximated activation of receptor subtypes may explain behavioral effects. Brain Res 2014; 1554:36-48. [PMID: 24472579 DOI: 10.1016/j.brainres.2014.01.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 12/19/2013] [Accepted: 01/20/2014] [Indexed: 12/24/2022]
Abstract
Enormous progress in understanding the role of four populations of benzodiazepine-sensitive GABAA receptors was paralleled by the puzzling findings suggesting that substantial separation of behavioral effects may be accomplished by apparently non-selective modulators. We report on SH-I-048A, a newly synthesized chiral positive modulator of GABAA receptors characterized by exceptional subnanomolar affinity, high efficacy and non-selectivity. Its influence on behavior was assessed in Wistar rats and contrasted to that obtained with 2mg/kg diazepam. SH-I-048A reached micromolar concentrations in brain tissue, while the unbound fraction in brain homogenate was around 1.5%. The approximated electrophysiological responses, which estimated free concentrations of SH-I-048A or diazepam are able to elicit, suggested a similarity between the 10mg/kg dose of the novel ligand and 2mg/kg diazepam; however, SH-I-048A was relatively more active at α1- and α5-containing GABAA receptors. Behaviorally, SH-I-048A induced sedative, muscle relaxant and ataxic effects, reversed mechanical hyperalgesia 24h after injury, while it was devoid of clear anxiolytic actions and did not affect water-maze performance. While lack of clear anxiolytic actions may be connected with an enhanced potentiation at α1-containing GABAA receptors, the observed behavior in the rotarod, water maze and peripheral nerve injury tests was possibly affected by its prominent action at receptors containing the α5 subunit. The current results encourage further innovative approaches aimed at linking in vitro and in vivo data in order to help define fine-tuning mechanisms at four sensitive receptor populations that underlie subtle differences in behavioral profiles of benzodiazepine site ligands.
Collapse
Affiliation(s)
- Aleksandar Lj Obradović
- Department of Physiology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Srđan Joksimović
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Michael M Poe
- Department of Chemistry and Biochemistry, University of Wisconsin - Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
| | - Joachim Ramerstorfer
- Department of Biochemistry and Molecular Biology, Center for Brain Research, Medical University Vienna, Vienna, Austria
| | - Zdravko Varagic
- Department of Biochemistry and Molecular Biology, Center for Brain Research, Medical University Vienna, Vienna, Austria
| | - Ojas Namjoshi
- Department of Chemistry and Biochemistry, University of Wisconsin - Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
| | - Bojan Batinić
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Tamara Radulović
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Bojan Marković
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Brian L Roth
- Department of Pharmacology, University of North Carolina Chapel Hill Medical School, Chapel Hill, NC 27514, USA; Division of Chemical Biology and Medicinal Chemistry, University of North Carolina Chapel Hill Medical School, Chapel Hill, NC 27514, USA
| | - Werner Sieghart
- Department of Biochemistry and Molecular Biology, Center for Brain Research, Medical University Vienna, Vienna, Austria
| | - James M Cook
- Department of Chemistry and Biochemistry, University of Wisconsin - Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
| | - Miroslav M Savić
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia.
| |
Collapse
|
26
|
Allosteric modulation of GABA(A) receptor subtypes:effects on visual recognition and visuospatial working memory in rhesus monkeys [corrected]. Neuropsychopharmacology 2013; 38:2315-25. [PMID: 23722241 PMCID: PMC3773684 DOI: 10.1038/npp.2013.137] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 05/21/2013] [Accepted: 05/21/2013] [Indexed: 11/08/2022]
Abstract
Non-selective positive allosteric modulators (PAMs) of GABAA receptors (GABAARs) are known to impair anterograde memory. The role of the various GABAAR subtypes in the memory-impairing effects of non-selective GABAAR PAMs has not been fully elucidated. The current study assessed, in rhesus monkeys, effects of modulation of α1, α2/3, and α5GABAARs on visual recognition and spatial working memory using delayed matching-to-sample (DMTS) and self-ordered spatial search (SOSS) procedures, respectively. The DMTS procedure (n=8) involved selecting a previously presented 'sample' image from a set of multiple images presented after a delay. The SOSS procedure (n=6) involved touching a number of boxes without repeats. The non-selective GABAAR PAM triazolam and the α1GABAA preferential PAMS zolpidem and zaleplon reduced accuracy in both procedures, whereas the α5GABAA preferential PAMs SH-053-2'F-R-CH3 and SH-053-2'F-S-CH3, and the α2/3GABAA preferential PAM TPA023B were without effects on accuracy or trial completion. The low-efficacy α5GABAAR negative allosteric modulator (NAM) PWZ-029 slightly increased only DMTS accuracy, whereas the high-efficacy α5GABAAR NAMs RY-23 and RY-24 did not affect accuracy under either procedure. Finally, the slopes of the accuracy dose-effect curves for triazolam, zolpidem, and zaleplon increased with box number in the SOSS procedure, but were equivalent across DMTS delays. The present results suggest that (1) α1GABAARs, compared with α2/3 and α5GABAARs, are primarily involved in the impairment, by non-selective GABAAR PAMs, of visual recognition and visuospatial working memory in nonhuman primates; and (2) relative cognitive impairment produced by positive modulation of GABAARs increases with number of locations to be remembered, but not with the delay for remembering.
Collapse
|
27
|
Fischer BD, Teixeira LP, van Linn ML, Namjoshi OA, Cook JM, Rowlett JK. Role of gamma-aminobutyric acid type A (GABAA) receptor subtypes in acute benzodiazepine physical dependence-like effects: evidence from squirrel monkeys responding under a schedule of food presentation. Psychopharmacology (Berl) 2013; 227:347-54. [PMID: 23354533 PMCID: PMC3637862 DOI: 10.1007/s00213-013-2975-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 12/19/2012] [Indexed: 11/25/2022]
Abstract
RATIONALE Assays of schedule-controlled responding can be used to characterize the pharmacology of benzodiazepines and other GABAA receptor modulators, and are sensitive to changes in drug effects that are related to physical dependence. OBJECTIVE The present study used this approach to investigate the role of GABAA receptor subtypes in mediating dependence-like effects following benzodiazepine administration. METHODS Squirrel monkeys (n = 6) were trained on a fixed-ratio schedule of food reinforcement. Initially, the response rate-decreasing effects of chlordiazepoxide (0.1-10 mg/kg; nonselective GABAA receptor agonist), zolpidem (0.032-1.0 mg/kg; α1 subunit-containing GABAA subtype-preferring agonist), and HZ-166 (0.1-10 mg/kg; functionally selective α2 and α3 subunit-containing GABAA receptor agonist) were assessed. Next, acute dependence-like effects following single injections of chlordiazepoxide, zolpidem, and HZ-166 were assessed with flumazenil (0.1-3.2 mg/kg; nonselective GABAA receptor antagonist). Finally, acute dependence-like effects following zolpidem administration were assessed with βCCt and 3-PBC (0.1-3.2 mg/kg and 0.32-10 mg/kg, respectively; α1 subunit-containing GABAA receptor antagonists). RESULTS Chlordiazepoxide, zolpidem, and HZ-166 produced dose- and time-dependent decreases in response rates, whereas flumazenil, βCCT, and 3-PBC were ineffective. After the drug effects waned, flumazenil produced dose-dependent decreases in response rates following administration of 10 mg/kg chlordiazepoxide and 1.0 mg/kg zolpidem, but not following any dose of HZ-166. Further, both βCCT and 3-PBC produced dose-dependent decreases in response rates when administered after 1.0 mg/kg zolpidem. CONCLUSIONS These data raise the possibility that α1 subunit-containing GABAA receptors play a major role in physical dependence-related behaviors following a single injection of a benzodiazepine.
Collapse
Affiliation(s)
| | | | | | | | | | - James K. Rowlett
- Corresponding Author: , Phone: (508) 624-8036, Fax: (508) 624-8197
| |
Collapse
|
28
|
Benzodiazepine-induced spatial learning deficits in rats are regulated by the degree of modulation of α1 GABA(A) receptors. Eur Neuropsychopharmacol 2013; 23:390-9. [PMID: 22633616 PMCID: PMC3448846 DOI: 10.1016/j.euroneuro.2012.05.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 02/25/2012] [Accepted: 05/05/2012] [Indexed: 11/21/2022]
Abstract
Despite significant advances in understanding the role of benzodiazepine (BZ)-sensitive populations of GABAA receptors, containing the α1, α2, α3 or α5 subunit, factual substrates of BZ-induced learning and memory deficits are not yet fully elucidated. It was shown that α1-subunit affinity-selective antagonist β-CCt almost completely abolished spatial learning deficits induced by diazepam (DZP) in the Morris water maze. We examined a novel, highly (105 fold) α1-subunit selective ligand-WYS8 (0.2, 1 and 10 mg/kg), on its own and in combination with the non-selective agonist DZP (2 mg/kg) or β-CCt (5 mg/kg) in the water maze in rats. The in vitro efficacy study revealed that WYS8 acts as α1-subtype selective weak partial positive modulator (40% potentiation at 100nM). Measurement of concentrations of WYS8 and DZP in rat serum and brain tissues suggested that they did not substantially cross-influence the respective disposition. In the water maze, DZP impaired spatial learning (acquisition trials) and memory (probe trial). WYS8 caused no effect per se, did not affect the overall influence of DZP on the water-maze performance and was devoid of any activity in this task when combined with β-CCt. Nonetheless, an additional analysis of the latency to reach the platform and the total distance swam suggested that WYS8 addition attenuated the run-down of the spatial impairment induced by DZP at the end of acquisition trials. These results demonstrate a clear difference in the influence of an α1 subtype-selective antagonist and a partial agonist on the effects of DZP on the water-maze acquisition.
Collapse
|
29
|
Khom S, Strommer B, Schöffmann A, Hintersteiner J, Baburin I, Erker T, Schwarz T, Schwarzer C, Zaugg J, Hamburger M, Hering S. GABAA receptor modulation by piperine and a non-TRPV1 activating derivative. Biochem Pharmacol 2013; 85:1827-36. [PMID: 23623790 PMCID: PMC3776227 DOI: 10.1016/j.bcp.2013.04.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 04/15/2013] [Accepted: 04/17/2013] [Indexed: 01/11/2023]
Abstract
The action of piperine (the pungent component of pepper) and its derivative SCT-66 ((2E,4E)-5-(1,3-benzodioxol-5-yl))-N,N-diisobutyl-2,4-pentadienamide) on different gamma-aminobutyric acid (GABA) type A (GABAA) receptors, transient-receptor-potential-vanilloid-1 (TRPV1) receptors and behavioural effects were investigated. GABAA receptor subtypes and TRPV1 receptors were expressed in Xenopus laevis oocytes. Modulation of GABA-induced chloride currents (IGABA) by piperine and SCT-66 and activation of TRPV1 was studied using the two-microelectrode-voltage-clamp technique and fast perfusion. Their effects on explorative behaviour, thermoregulation and seizure threshold were analysed in mice. Piperine acted with similar potency on all GABAA receptor subtypes (EC50 range: 42.8 ± 7.6 μM (α2β2)–59.6 ± 12.3 μM (α3β2)). IGABA modulation by piperine did not require the presence of a γ2S-subunit, suggesting a binding site involving only α and β subunits. IGABA activation was slightly more efficacious on receptors formed from β2/3 subunits (maximal IGABA stimulation through α1β3 receptors: 332 ± 64% and α1β2: 271 ± 36% vs. α1β1: 171 ± 22%, p < 0.05) and α3-subunits (α3β2: 375 ± 51% vs. α5β2:136 ± 22%, p < 0.05). Replacing the piperidine ring by a N,N-diisobutyl residue (SCT-66) prevents interactions with TRPV1 and simultaneously increases the potency and efficiency of GABAA receptor modulation. SCT-66 displayed greater efficacy on GABAA receptors than piperine, with different subunit-dependence. Both compounds induced anxiolytic, anticonvulsant effects and reduced locomotor activity; however, SCT-66 induced stronger anxiolysis without decreasing body temperature and without the proconvulsive effects of TRPV1 activation and thus may serve as a scaffold for the development of novel GABAA receptor modulators.
Collapse
Affiliation(s)
- Sophia Khom
- Department of Pharmacology and Toxicology, University of Vienna, Althanstraße 14, A-1090 Wien, Austria
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Drexler B, Zinser S, Huang S, Poe MM, Rudolph U, Cook JM, Antkowiak B. Enhancing the function of alpha5-subunit-containing GABAA receptors promotes action potential firing of neocortical neurons during up-states. Eur J Pharmacol 2013; 703:18-24. [PMID: 23380687 DOI: 10.1016/j.ejphar.2013.01.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 01/12/2013] [Accepted: 01/16/2013] [Indexed: 11/27/2022]
Abstract
Neocortical neurons mediate the sedative and anticonvulsant properties of benzodiazepines. These agents enhance synaptic inhibition via positive modulation of γ-aminobutyric acid (GABAA) receptors harboring α1-, α2-, α3- or α5-protein subunits. Benzodiazepine-sensitive GABAA receptors containing the α5-subunit are abundant in the neocortex, but their impact in controlling neuronal firing patterns is unknown. Here we studied how the discharge rates of cortical neurons are modified by a positive (SH-053-2'F-R-CH3) and a negative (L 655,708) α5-subunit-preferring allosteric modulator in comparison to diazepam, the classical non-selective benzodiazepine. Drug actions were characterized in slice cultures from wild-type and α5(H105R) knock-in mice by performing extracellular multi-unit-recordings. In knock-in mice, receptors containing the α5 subunit are insensitive to benzodiazepines. The non-selective positive allosteric modulator diazepam decreased the discharge rates of neocortical neurons during episodes of ongoing neuronal activity (up states). In contrast to diazepam, the α5-preferring positive modulator SH-053-2'F-R-CH3 accelerated action potential firing during up states. This promoting action was absent in slices from α5(H105R) mice, confirming that it is mediated by the α5-subunit. Consistent with these observations, the negative α5-selective modulator L 655,708 inhibited up state action potential activity in slices from wild-type mice. The opposing actions of diazepam and SH-053-2'F-R-CH3, which both enhance GABAA receptor function but differ in subtype-selectivity, uncovers contrasting roles of GABAA receptor subtypes in controlling the firing rates of cortical neurons. These findings may have important implications for the design of novel anaesthetic and anticonvulsant benzodiazepines displaying an improved efficacy and fewer side effects.
Collapse
Affiliation(s)
- Berthold Drexler
- Experimental Anaesthesiology Section, Department of Anaesthesiology and Intensive Care Medicine, Eberhard-Karls-University, 72072 Tuebingen, Germany.
| | | | | | | | | | | | | |
Collapse
|
31
|
Midazolam impairs acquisition and retrieval, but not consolidation of reference memory in the Morris water maze. Behav Brain Res 2012; 241:198-205. [PMID: 23261388 DOI: 10.1016/j.bbr.2012.12.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 12/07/2012] [Accepted: 12/10/2012] [Indexed: 01/10/2023]
Abstract
Amnesia is one of the most discussed properties of the benzodiazepine class of drugs. The effects of benzodiazepines on human memory are usually anterograde, while changes in retrograde memory functions were seldom reported. Such inconsistent findings have prompted numerous animal studies investigating the influences of these positive modulators of inhibitory neurotransmission on different stages of memory. Among the benzodiazepines, memory effects of midazolam are of special interest due to its many and varied clinical applications. The present Morris water maze study in adult male Wistar rats was performed in three experiments in which midazolam was administered at doses of 0.5, 1 and 2 mg/kg intraperitoneally, before or immediately after each of five daily learning sessions, with two trials in a session, as well as before the probe test. Midazolam impaired acquisition and subsequent retention of spatial learning of the position of the hidden platform even at a pre-training dose of 0.5 mg/kg. This low dose was not associated with impairment of the procedural component of learning, manifested by increased time spent in the periphery of the pool. The lack of midazolam effect on consolidation has not been confounded by the observed below-chance performance of the control group since our additional experiment using diazepam also administered immediately after each of five learning sessions has revealed a similar pattern of results. Finally, midazolam administered before the probe test impaired retrieval of reference memory at all tested doses. Hence, induction of retrograde, besides anterograde amnesia should be kept in mind as a possibility when midazolam is used in clinical settings.
Collapse
|
32
|
Namjoshi OA, Wang ZJ, Rallapalli SK, Johnson EM, Johnson YT, Ng H, Ramerstorfer J, Varagic Z, Sieghart W, Majumder S, Roth BL, Rowlett JK, Cook JM. Search for α3β₂/₃γ2 subtype selective ligands that are stable on human liver microsomes. Bioorg Med Chem 2012; 21:93-101. [PMID: 23218469 DOI: 10.1016/j.bmc.2012.10.057] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 10/22/2012] [Accepted: 10/31/2012] [Indexed: 11/27/2022]
Abstract
Selective modulation of specific benzodiazepine receptor (BzR) gamma amino butyric acid-A (GABA(A)) receptor ion channels has been identified as an important method for separating out the variety of pharmacological effects elicited by BzR-related drugs. Importantly, it has been demonstrated that both α2β(2/3)γ2 (α2BzR) and α3BzR (and/or α2/α3) BzR subtype selective ligands exhibit anxiolytic effects with little or no sedation. Previously we have identified several such ligands; however, three of our parent ligands exhibited significant metabolic liability in rodents in the form of a labile ester group. Here eight analogs are reported which were designed to circumvent this liability by utilizing a rational replacement of the ester moiety based on medicinal chemistry precedents. In a metabolic stability study using human liver microsomes, four compounds were found to undergo slower metabolic transformation, as compared to their corresponding ester analogs. These compounds were also evaluated in in vitro efficacy assays. Additionally, bioisostere 11 was evaluated in a rodent model of anxiety. It exhibited anxiolytic activity at doses of 10 and 100mg/kg and was devoid of sedative properties.
Collapse
Affiliation(s)
- Ojas A Namjoshi
- Department of Chemistry, University of Wisconsin-Milwaukee, PO Box 413, Milwaukee, WI 53211, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Divljaković J, Milić M, Namjoshi OA, Tiruveedhula VV, Timić T, Cook JM, Savić MM. βCCT, an antagonist selective for α(1)GABA(A) receptors, reverses diazepam withdrawal-induced anxiety in rats. Brain Res Bull 2012; 91:1-7. [PMID: 23149168 DOI: 10.1016/j.brainresbull.2012.10.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 10/29/2012] [Accepted: 10/31/2012] [Indexed: 10/27/2022]
Abstract
The abrupt discontinuation of prolonged benzodiazepine treatment elicits a withdrawal syndrome with increased anxiety as a major symptom. The neural mechanisms underlying benzodiazepine physical dependence are still insufficiently understood. Flumazenil, the non-selective antagonist of the benzodiazepine binding site of GABA(A) receptors was capable of preventing and reversing the increased anxiety during benzodiazepine withdrawal in animals and humans in some, but not all studies. On the other hand, a number of data suggest that GABA(A) receptors containing α(1) subunits are critically involved in processes developing during prolonged use of benzodiazepines, such are tolerance to sedative effects, liability to physical dependence and addiction. Hence, we investigated in the elevated plus maze the level of anxiety 24 h following 21 days of diazepam treatment and the influence of flumazenil or a preferential α(1)-subunit selective antagonist βCCt on diazepam withdrawal syndrome in rats. Abrupt cessation of protracted once-daily intraperitoneal administration of 2 mg/kg diazepam induced a withdrawal syndrome, measured by increased anxiety-like behavior in the elevated plus maze 24 h after treatment cessation. Acute challenge with either flumazenil (10mg/kg) or βCCt (1.25, 5 and 20 mg/kg) alleviated the diazepam withdrawal-induced anxiety. Moreover, both antagonists induced an anxiolytic-like response close, though not identical, to that seen with acute administration of diazepam. These findings imply that the mechanism by which antagonism at GABA(A) receptors may reverse the withdrawal-induced anxiety involves the α(1) subunit and prompt further studies aimed at linking the changes in behavior with possible adaptive changes in subunit expression and function of GABA(A) receptors.
Collapse
Affiliation(s)
- Jovana Divljaković
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | | | | | | | | | | | | |
Collapse
|
34
|
Tolerance liability of diazepam is dependent on the dose used for protracted treatment. Pharmacol Rep 2012; 64:1116-25. [DOI: 10.1016/s1734-1140(12)70908-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 05/23/2012] [Indexed: 11/18/2022]
|
35
|
Vinkers CH, Hendriksen H, van Oorschot R, Cook JM, Rallipalli S, Huang S, Millan MJ, Olivier B, Groenink L. Lifelong CRF overproduction is associated with altered gene expression and sensitivity of discrete GABA(A) and mGlu receptor subtypes. Psychopharmacology (Berl) 2012; 219:897-908. [PMID: 21833506 PMCID: PMC3259347 DOI: 10.1007/s00213-011-2423-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2011] [Accepted: 07/15/2011] [Indexed: 12/22/2022]
Abstract
RATIONALE Repeated activation of corticotropin-releasing factor (CRF) receptors is associated with increased anxiety and enhanced stress responsivity, which may be mediated via limbic GABAergic and glutamatergic transmission. OBJECTIVE The present study investigated molecular and functional alterations in GABA(A) receptor (GABA(A)R) and metabotropic glutamate receptor (mGluR) responsivity in transgenic mice that chronically overexpress CRF. METHODS CRF(1) receptor, GABA(A)R, and mGluR sensitivity were determined in CRF-overexpressing mice using the stress-induced hyperthermia (SIH) test. In addition, we measured mRNA expression levels of GABA(A)R α subunits and mGluRs in the amygdala and hypothalamus. RESULTS CRF-overexpressing mice were less sensitive to the anxiolytic effects of the CRF(1) receptor antagonists CP154,526 and DMP695, the GABA(A)R α(3)-selective agonist TP003 (0-3 mg/kg) and the mGluR(2/3) agonist LY379268 (0-10 mg/kg) in the SIH test. The hypothermic effect of the non-selective GABA(A)R agonist diazepam (0-4 mg/kg) and the α(1)-subunit-selective GABA(A)R agonist zolpidem (0-10 mg/kg) was reduced in CRF-overexpressing mice. No genotype differences were found using the GABA(A)R α(5)-subunit preferential compound SH-053-2'F-R-CH(3) and mGluR(5) antagonists MPEP and MTEP. CRF-overexpressing mice showed decreased expression levels of GABA(A)R α(2) subunit and mGluR(3) mRNA levels in the amygdala, whereas these expression levels were increased in the hypothalamus. CRF-overexpressing mice also showed increased hypothalamic mRNA levels of α(1) and α(5) GABA(A)R subunits. CONCLUSIONS We found that lifelong CRF overproduction is associated with altered gene expression and reduced functional sensitivity of discrete GABA(A) and mGluR receptor subtypes. These findings suggest that sustained over-activation of cerebral CRF receptors may contribute to the development of altered stress-related behavior via modulation of GABAergic and glutamatergic transmission.
Collapse
Affiliation(s)
- Christiaan H Vinkers
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences and Rudolf Magnus Institute of Neuroscience, Utrecht University, Universiteitsweg 99, 3584CG Utrecht, The Netherlands.
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
A novel α5GABA(A)R-positive allosteric modulator reverses hyperactivation of the dopamine system in the MAM model of schizophrenia. Neuropsychopharmacology 2011; 36:1903-11. [PMID: 21562483 PMCID: PMC3154109 DOI: 10.1038/npp.2011.76] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
We have shown previously that aberrant hippocampal (HPC) output underlies the dopamine (DA) dysfunction observed in the methylazoxymethanol acetate (MAM) developmental model of schizophrenia in the rodent. This alteration of HPC activity was proposed to result from a reduction in parvalbumin (PV)-expressing GABAergic interneurons and consequent destabilization of the output of pyramidal neurons, as well as disrupted activation across a broad neural network. In vivo extracellular recordings were performed in the ventral tegmental area (VTA) and ventral HPC of saline- (SAL) and MAM-treated animals. A novel benzodiazepine-positive allosteric modulator (PAM), selective for the α5 subunit of the GABA(A) receptor, SH-053-2'F-R-CH3, was tested for its effects on the output of the HPC, leading to dopamine system hyperactivity in MAM-treated animals. In addition, the effect of SH-053-2'F-R-CH3 on the hyperactive locomotor response to amphetamine in MAM animals was examined. We demonstrate that treatment with the α5GABA(A)R PAM reduced the number of spontaneously active DA neurons in the VTA of MAM animals to levels observed in SAL rats, both when administered systemically and when directly infused into the ventral HPC. Moreover, HPC neurons in both SAL and MAM animals showed diminished cortical-evoked responses following α5GABA(A)R PAM treatment. In addition, the increased locomotor response to amphetamine observed in MAM rats was reduced following α5GABA(A)R treatment. This study supports a novel treatment of schizophrenia that targets abnormal HPC output, which in turn normalizes dopaminergic neuronal activity.
Collapse
|
37
|
Use of multicomponent reactions in developing small-molecule tools to study GABAA receptor mechanism and function. Future Med Chem 2011; 3:243-50. [PMID: 21428818 DOI: 10.4155/fmc.10.302] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
We discuss the potential use of multicomponent reactions in developing small-molecule probes of GABA(A) receptor function. Two examples that illustrate this approach are presented: the synthesis of a class of compounds that specifically modulate the function of GABA(A) receptors containing the δ-subunit, and also 'caged' GABA derivatives. A caged GABA is a photolabile precursor of GABA that releases GABA upon photolysis.
Collapse
|
38
|
Lodge DJ, Grace AA. Hippocampal dysregulation of dopamine system function and the pathophysiology of schizophrenia. Trends Pharmacol Sci 2011; 32:507-13. [PMID: 21700346 DOI: 10.1016/j.tips.2011.05.001] [Citation(s) in RCA: 241] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 05/04/2011] [Accepted: 05/06/2011] [Indexed: 01/11/2023]
Abstract
Substantial evidence suggests that psychosis in schizophrenia is associated with dysregulation of subcortical dopamine system function. Here we examine evidence that this dysregulation is secondary to hyperactivity within hippocampal subfields. Enhanced hippocampal activity has been reported in preclinical models and in schizophrenia patients. Moreover, this hippocampal hyperactivity is correlated with enhanced dopamine neuron activity and positive symptoms, respectively. Thus, restoration of hippocampal function could provide a more effective therapeutic approach than current therapeutics based on blockade of dopamine D2 receptors. Indeed, initial studies demonstrate that allosteric modulation of the α5GABA(A) receptor can decrease aberrant dopamine signaling and associated behaviors in a verified rodent model of psychosis.
Collapse
Affiliation(s)
- Daniel J Lodge
- Department of Pharmacology and Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | | |
Collapse
|
39
|
Grace AA. Dopamine system dysregulation by the hippocampus: implications for the pathophysiology and treatment of schizophrenia. Neuropharmacology 2011; 62:1342-8. [PMID: 21621548 DOI: 10.1016/j.neuropharm.2011.05.011] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 05/11/2011] [Accepted: 05/13/2011] [Indexed: 11/19/2022]
Abstract
For decades, the predominant hypothesis of schizophrenia centered on dysfunctions of the dopamine system. However, recent evidence now suggests that the dopamine system may be "normal" in its configuration, but instead is regulated abnormally by modulatory processes. Convergent studies in animals and in humans have now focused on the hippocampus as a central component in the generation of psychosis and possibly other symptom states in schizophrenia. Thus, activity in the ventral hippocampus has been shown to regulate dopamine neuron responsivity by controlling the number of dopamine neurons that can be phasically activated by stimuli. In this way, this structure determines the gain of the dopamine signal in response to stimuli. However, in schizophrenia, the hippocampus appears to be hyper-active, possibly due to attenuation of function of inhibitory interneurons. As a result, the dopamine system is driven into an overly responsive state. Current medications have focused on blockade of overstimulated dopamine receptors; however, this now appears to be several synapses downstream from the pathological antecedent. Therapeutic approaches that focus on normalizing hippocampal function may prove to be more effective treatment avenues for the schizophrenia patient.
Collapse
Affiliation(s)
- Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, 458 Crawford Hall, Pittsburgh, PA 15260, USA.
| |
Collapse
|