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Akotkar L, Aswar U, Ganeshpurkar A, Rathod K, Bagad P, Gurav S. Phytoconstituents Targeting the Serotonin 5-HT 3 Receptor: Promising Therapeutic Strategies for Neurological Disorders. ACS Pharmacol Transl Sci 2024; 7:1694-1710. [PMID: 38898946 PMCID: PMC11184608 DOI: 10.1021/acsptsci.4c00084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 05/17/2024] [Accepted: 05/21/2024] [Indexed: 06/21/2024]
Abstract
The 5-hydroxytryptamine-3 receptor (5-HT3R), a subtype of serotonin receptor, is a ligand-gated ion channel crucial in mediating fast synaptic transmission in the central and peripheral nervous systems. This receptor significantly influences various neurological activities, encompassing neurotransmission, mood regulation, and cognitive processing; hence, it may serve as an innovative target for neurological disorders. Multiple studies have revealed promising results regarding the beneficial effects of these phytoconstituents and extracts on conditions such as nausea, vomiting, neuropathic pain depression, anxiety, Alzheimer's disease, cognition, epilepsy, sleep, and dyskinesia via modulation of 5-HT3R in the pathophysiology of neurological disorder. The review delves into a detailed exploration of in silico, in vitro, and in vivo studies and clinical studies that discussed phytoconstituents acting on 5-HT3R and attenuates difficulties in neurological diseases. The diverse mechanisms by which plant-derived phytoconstituents influence 5-HT3R activity offer exciting avenues for developing innovative therapeutic interventions. Besides producing an agonistic or antagonistic effect, some phytoconstituents exert modulatory effects on 5-HT3R activity through multifaceted mechanisms. These include γ-aminobutyric acid and cholinergic neuronal pathways, interactions with neurokinin (NK)-1, NK2, serotonergic, and γ-aminobutyric acid(GABA)ergic systems, dopaminergic influences, and mediation of calcium ions release and inflammatory cascades. Notably, the phytoconstituent's capacity to reduce oxidative stress has also emerged as a significant factor contributing to their modulatory role. Despite the promising implications, there is currently a dearth of exploration needed to understand the effect of phytochemicals on the 5-HT3R. Comprehensive preclinical and clinical research is of the utmost importance to broaden our knowledge of the potential therapeutic benefits associated with these substances.
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Affiliation(s)
- Likhit Akotkar
- Department
of Pharmacology, Poona College of Pharmacy,
Bharati Vidyapeeth (Deemed to be University), Pune 411038, India
| | - Urmila Aswar
- Department
of Pharmacology, Poona College of Pharmacy,
Bharati Vidyapeeth (Deemed to be University), Pune 411038, India
| | - Ankit Ganeshpurkar
- Department
of Pharmaceutical Chemistry, Poona College
of Pharmacy, Bharati Vidyapeeth (Deemed to be University), Pune411038, India
| | - Kundlik Rathod
- Department
of Pharmacology, Poona College of Pharmacy,
Bharati Vidyapeeth (Deemed to be University), Pune 411038, India
| | - Pradnya Bagad
- Department
of Pharmacology, Poona College of Pharmacy,
Bharati Vidyapeeth (Deemed to be University), Pune 411038, India
| | - Shailendra Gurav
- Department
of Pharmacognosy, Goa College of Pharmacy, Goa University, Goa 403001, India
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Abstract
The α7-type nicotinic acetylcholine receptor is one of the most unique and interesting of all the members of the cys-loop superfamily of ligand-gated ion channels. Since it was first identified initially as a binding site for α-bungarotoxin in mammalian brain and later as a functional homomeric receptor with relatively high calcium permeability, it has been pursued as a potential therapeutic target for numerous indications, from Alzheimer disease to asthma. In this review, we discuss the history and state of the art for targeting α7 receptors, beginning with subtype-selective agonists and the basic pharmacophore for the selective activation of α7 receptors. A key feature of α7 receptors is their rapid desensitization by standard "orthosteric" agonist, and we discuss insights into the conformational landscape of α7 receptors that has been gained by the development of ligands binding to allosteric sites. Some of these sites are targeted by positive allosteric modulators that have a wide range of effects on the activation profile of the receptors. Other sites are targeted by direct allosteric agonist or antagonists. We include a perspective on the potential importance of α7 receptors for metabotropic as well as ionotropic signaling. We outline the challenges that exist for future development of drugs to target this important receptor and approaches that may be considered to address those challenges. SIGNIFICANCE STATEMENT: The α7-type nicotinic acetylcholine receptor (nAChR) is acknowledged as a potentially important therapeutic target with functional properties associated with both ionotropic and metabotropic signaling. The functional properties of α7 nAChR can be regulated in diverse ways with the variety of orthosteric and allosteric ligands described in this review.
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Affiliation(s)
- Roger L Papke
- Departments of Pharmacology and Therapeutics (R.L.P) and Chemistry (N.A.H.), University of Florida, Gainesville, FL
| | - Nicole A Horenstein
- Departments of Pharmacology and Therapeutics (R.L.P) and Chemistry (N.A.H.), University of Florida, Gainesville, FL
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Martín-Sánchez C, Alés E, Balseiro-Gómez S, Atienza G, Arnalich F, Bordas A, Cedillo JL, Extremera M, Chávez-Reyes A, Montiel C. The human-specific duplicated α7 gene inhibits the ancestral α7, negatively regulating nicotinic acetylcholine receptor-mediated transmitter release. J Biol Chem 2021; 296:100341. [PMID: 33515545 PMCID: PMC7949125 DOI: 10.1016/j.jbc.2021.100341] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/13/2021] [Accepted: 01/21/2021] [Indexed: 12/31/2022] Open
Abstract
Gene duplication generates new functions and traits, enabling evolution. Human-specific duplicated genes in particular are primary sources of innovation during our evolution although they have very few known functions. Here we examine the brain function of one of these genes (CHRFAM7A) and its product (dupα7 subunit). This gene results from a partial duplication of the ancestral CHRNA7 gene encoding the α7 subunit that forms the homopentameric α7 nicotinic acetylcholine receptor (α7-nAChR). The functions of α7-nAChR in the brain are well defined, including the modulation of synaptic transmission and plasticity underlying normal attention, cognition, learning, and memory processes. However, the role of the dupα7 subunit remains unexplored at the neuronal level. Here, we characterize that role by combining immunoblotting, quantitative RT-PCR and FRET techniques with functional assays of α7-nAChR activity using human neuroblastoma SH-SY5Y cell variants with different dupα7 expression levels. Our findings reveal a physical interaction between dupα7 and α7 subunits in fluorescent protein-tagged dupα7/α7 transfected cells that negatively affects normal α7-nAChR activity. Specifically, in both single cells and cell populations, the [Ca2+]i signal and the exocytotic response induced by selective stimulation of α7-nAChR were either significantly inhibited by stable dupα7 overexpression or augmented after silencing dupα7 gene expression with specific siRNAs. These findings identify a new role for the dupα7 subunit as a negative regulator of α7-nAChR-mediated control of exocytotic neurotransmitter release. If this effect is excessive, it would result in an impaired synaptic transmission that could underlie the neurocognitive and neuropsychiatric disorders associated with α7-nAChR dysfunction.
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Affiliation(s)
- Carolina Martín-Sánchez
- Department of Pharmacology and Therapeutics, Medical School, Universidad Autónoma de Madrid, Madrid, Spain
| | - Eva Alés
- Department of Medical Physiology and Biophysics, Medical School, Universidad de Sevilla, Sevilla, Spain
| | - Santiago Balseiro-Gómez
- Department of Medical Physiology and Biophysics, Medical School, Universidad de Sevilla, Sevilla, Spain
| | - Gema Atienza
- Department of Pharmacology and Therapeutics, Medical School, Universidad Autónoma de Madrid, Madrid, Spain
| | - Francisco Arnalich
- Internal Medicine Service, University Hospital La Paz-IdiPAZ, Madrid, Spain
| | - Anna Bordas
- Department of Pharmacology and Therapeutics, Medical School, Universidad Autónoma de Madrid, Madrid, Spain
| | - José L Cedillo
- Department of Pharmacology and Therapeutics, Medical School, Universidad Autónoma de Madrid, Madrid, Spain
| | - María Extremera
- Department of Pharmacology and Therapeutics, Medical School, Universidad Autónoma de Madrid, Madrid, Spain
| | | | - Carmen Montiel
- Department of Pharmacology and Therapeutics, Medical School, Universidad Autónoma de Madrid, Madrid, Spain.
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Ren JM, Zhang SL, Wang XL, Guan ZZ, Qi XL. Expression levels of the α7 nicotinic acetylcholine receptor in the brains of patients with Alzheimer's disease and their effect on synaptic proteins in SH-SY5Y cells. Mol Med Rep 2020; 22:2063-2075. [PMID: 32582986 PMCID: PMC7411404 DOI: 10.3892/mmr.2020.11253] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 06/04/2020] [Indexed: 01/22/2023] Open
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative, and abnormal aggregation of the neurotoxic β amyloid (Aβ) peptide is an early event in AD. The present study aimed to determine the correlation between the nicotinic acetylcholine receptor α7 subunit (α7 nAChR) and Aβ in the brains of patients with AD, and to investigate whether the increased expression levels of the α7 nAChR could alter the neurotoxicity of Aβ. The expression levels of α7 nAChR and Aβ in the brains of patients with AD and healthy brains were analyzed using immunofluorescence. Moreover, SH‑SY5Y cells were used to stably overexpress or silence α7 nAChR expression levels, prior to the treatment with or without 1 µmol/l Aβ1‑42 oligomer (AβO). The mRNA and protein expression levels of α7 nAChR, synaptophysin (SYP), postsynaptic density of 95 kDa (PSD‑95) and synaptosomal‑associated protein of 25 kDa (SNAP‑25) were subsequently analyzed using reverse transcription‑quantitative PCR and western blotting. In addition, the concentration of acetylcholine (ACh) and the activity of acetylcholinesterase (AChE) were analyzed using spectrophotometry, while the cell apoptotic rate was determined using flow cytometry. The expression of Aβ in the brains of patients with AD was found to be significantly increased, whereas the expression of α7 nAChR was significantly decreased compared with the healthy control group. In vitro, the expression levels of α7 nAChR were significantly increased or decreased following the overexpression or silencing of the gene, respectively. Consistent with these observations, the mRNA and protein expression levels of SYP, PSD‑95 and SNAP‑25 were also significantly increased following the overexpression of α7 nAChR and decreased following the genetic silencing of the receptor. In untransfected or negative control cells, the expression levels of these factors and the apoptotic rate were significantly reduced following the exposure to AβO, which was found to be attenuated by α7 nAChR overexpression, but potentiated by α7 nAChR RNA silencing. However, no significant differences were observed in either the ACh concentration or AChE activity following transfection. Collectively, these findings suggested that α7 nAChR may protect the brains of patients with AD against Aβ, as α7 nAChR overexpression increased the expression levels of SYP, SNAP‑25 and PSD‑95, and attenuated the inhibitory effect of Aβ on the expression of these synaptic proteins and cell apoptosis. Overall, this indicated that α7 nAChR may serve an important neuroprotective role in AD.
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Affiliation(s)
- Jia-Mou Ren
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
- Key Laboratory of Medical Molecular Biology, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
- Department of Basic Medicine, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Shu-Li Zhang
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
- Key Laboratory of Medical Molecular Biology, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
- Chinese People's Liberation Army, Secret Service Center Sanatorium of Xiamen, Xiamen, Fujian 361000, P.R. China
| | - Xiao-Ling Wang
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
- Key Laboratory of Medical Molecular Biology, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Zhi-Zhong Guan
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
- Key Laboratory of Medical Molecular Biology, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
- Department of Pathology, Affiliated Hospital of Guizhou Medical University, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Xiao-Lan Qi
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
- Key Laboratory of Medical Molecular Biology, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
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Divanbeigi A, Nasehi M, Vaseghi S, Amiri S, Zarrindast MR. Tropisetron But Not Granisetron Ameliorates Spatial Memory Impairment Induced by Chronic Cerebral Hypoperfusion. Neurochem Res 2020; 45:2631-2640. [PMID: 32797381 DOI: 10.1007/s11064-020-03110-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 08/03/2020] [Accepted: 08/08/2020] [Indexed: 12/16/2022]
Abstract
Tropisetron and Granisetorn are 5-HT3 antagonists with antiemetic effects. Tropisetron also has a partial agonistic effect on alpha-7 nicotinic acetylcholine receptors (α7 nAChRs). On the other hand, chronic cerebral hypoperfusion (CCH) attenuates cerebral blood flow and impairs cognitive functions. The goal of this study was to investigate the effect of Tropisetron and Granisetron on CCH-induced spatial memory impairment in rats. Forty-eight male Wistar rats were used in this study. 2-VO surgery was done to induce CCH and Radial Eight Arm Maz apparatus was used to evaluate spatial memory (working and reference memory). Tropisetron was injected intraperitoneally at the doses of 1 and 5 mg/kg, and Granisetron was injected intraperitoneally at the dose of 3 mg/kg. Dorsal hippocampal (CA1) neurons count, Interleukin 6 (IL-6) serum level, and serotonin-reuptake transporter (SERT) gene expression were also evaluated. The results showed, CCH impaired working and reference memory, increased IL-6 serum level, and decreased CA1 neurons and SERT expression. Tropisetron at the dose of 5 mg/kg restored all the effects of CCH. However, Granisetron did not restore CCH-induced memory impairment. Furthermore, Granisetron had no effect on IL-6. While, it increased SERT expression and CA1 neurons. In conclusion, Tropisetron but not Granisetron, ameliorated spatial memory impairment induced by CCH. We suggested conducting more detailed studies investigating the role of serotonergic system (5-HT3 receptors and serotonin transporters) and also α7 nAChRs in the effects of Tropisetron.
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Affiliation(s)
- Ashkan Divanbeigi
- Department of Cognitive Neuroscience, Institute for Cognitive Science Studies (ICSS), Tehran, Iran.,Scientific Research Committee, Functional Neurosurgery Research Center, Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Nasehi
- Cognitive and Neuroscience Research Center (CNRC), Amir-Almomenin Hospital, Tehran Medical Sciences, Islamic Azad University, P.O. Box 13145-784, Tehran, Iran.
| | - Salar Vaseghi
- Department of Cognitive Neuroscience, Institute for Cognitive Science Studies (ICSS), Tehran, Iran.,Cognitive and Neuroscience Research Center (CNRC), Amir-Almomenin Hospital, Tehran Medical Sciences, Islamic Azad University, P.O. Box 13145-784, Tehran, Iran
| | - Sepideh Amiri
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran
| | - Mohammad-Reza Zarrindast
- Department of Cognitive Neuroscience, Institute for Cognitive Science Studies (ICSS), Tehran, Iran.,Cognitive and Neuroscience Research Center (CNRC), Amir-Almomenin Hospital, Tehran Medical Sciences, Islamic Azad University, P.O. Box 13145-784, Tehran, Iran.,Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.,Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran
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6
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Wang X, Daley C, Gakhar V, Lange HS, Vardigan JD, Pearson M, Zhou X, Warren L, Miller CO, Belden M, Harvey AJ, Grishin AA, Coles CJ, O'Connor SM, Thomson F, Duffy JL, Bell IM, Uslaner JM. Pharmacological Characterization of the Novel and Selective α7 Nicotinic Acetylcholine Receptor-Positive Allosteric Modulator BNC375. J Pharmacol Exp Ther 2020; 373:311-324. [PMID: 32094294 DOI: 10.1124/jpet.119.263483] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 02/17/2020] [Indexed: 12/28/2022] Open
Abstract
Treatments for cognitive deficits associated with central nervous system (CNS) disorders such as Alzheimer disease and schizophrenia remain significant unmet medical needs that incur substantial pressure on the health care system. The α7 nicotinic acetylcholine receptor (nAChR) has garnered substantial attention as a target for cognitive deficits based on receptor localization, robust preclinical effects, genetics implicating its involvement in cognitive disorders, and encouraging, albeit mixed, clinical data with α7 nAChR orthosteric agonists. Importantly, previous orthosteric agonists at this receptor suffered from off-target activity, receptor desensitization, and an inverted U-shaped dose-effect curve in preclinical assays that limit their clinical utility. To overcome the challenges with orthosteric agonists, we have identified a novel selective α7 positive allosteric modulator (PAM), BNC375. This compound is selective over related receptors and potentiates acetylcholine-evoked α7 currents with only marginal effect on the receptor desensitization kinetics. In addition, BNC375 enhances long-term potentiation of electrically evoked synaptic responses in rat hippocampal slices and in vivo. Systemic administration of BNC375 reverses scopolamine-induced cognitive deficits in rat novel object recognition and rhesus monkey object retrieval detour (ORD) task over a wide range of exposures, showing no evidence of an inverted U-shaped dose-effect curve. The compound also improves performance in the ORD task in aged African green monkeys. Moreover, ex vivo 13C-NMR analysis indicates that BNC375 treatment can enhance neurotransmitter release in rat medial prefrontal cortex. These findings suggest that α7 nAChR PAMs have multiple advantages over orthosteric α7 nAChR agonists for the treatment of cognitive dysfunction associated with CNS diseases. SIGNIFICANCE STATEMENT: BNC375 is a novel and selective α7 nicotinic acetylcholine receptor (nAChR) positive allosteric modulator (PAM) that potentiates acetylcholine-evoked α7 currents in in vitro assays with little to no effect on the desensitization kinetics. In vivo, BNC375 demonstrated robust procognitive effects in multiple preclinical models across a wide exposure range. These results suggest that α7 nAChR PAMs have therapeutic potential in central nervous system diseases with cognitive impairments.
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Affiliation(s)
- Xiaohai Wang
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Christopher Daley
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Vanita Gakhar
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Henry S Lange
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Joshua D Vardigan
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Michelle Pearson
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Xiaoping Zhou
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Lee Warren
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Corin O Miller
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Michelle Belden
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Andrew J Harvey
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Anton A Grishin
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Carolyn J Coles
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Susan M O'Connor
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Fiona Thomson
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Joseph L Duffy
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Ian M Bell
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
| | - Jason M Uslaner
- Merck Research Laboratories, Merck & Co., Inc., Kenilworth, New Jersey (X.W., C.D., V.G., H.S.L., J.D.V., M.P., X.Z., L.W., C.O.M., M.B., F.T., J.L.D., I.M.B., J.M.U.) and Bionomics Limited, Thebarton, Australia (A.J.H., A.A.G., C.J.C., S.M.O.)
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7
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Wang X, Bell IM, Uslaner JM. Activators of α7 nAChR as Potential Therapeutics for Cognitive Impairment. Curr Top Behav Neurosci 2020; 45:209-245. [PMID: 32451955 DOI: 10.1007/7854_2020_140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The α7 nicotinic acetylcholine receptor (nAChR) is a promising target for the treatment of cognitive deficits associated with psychiatric and neurological disorders, including schizophrenia and Alzheimer's disease (AD). Several α7 nAChR agonists and positive allosteric modulators (PAMs) have demonstrated procognitive effects in preclinical models and early clinical trials. However, despite intense research efforts in the pharmaceutical industry and academia, none of the α7 nAChR ligands has been approved for clinical use. This chapter will focus on the α7 nAChR ligands that have advanced to clinical studies and explore the reasons why these agents have not met with unequivocal clinical success.
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Affiliation(s)
- Xiaohai Wang
- Department of Neuroscience Research, Merck & Co. Inc., West Point, PA, USA
| | - Ian M Bell
- Department of Discovery Chemistry, Merck & Co. Inc., West Point, PA, USA
| | - Jason M Uslaner
- Department of Neuroscience Research, Merck & Co. Inc., West Point, PA, USA.
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8
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Fakhfouri G, Rahimian R, Dyhrfjeld-Johnsen J, Zirak MR, Beaulieu JM. 5-HT 3 Receptor Antagonists in Neurologic and Neuropsychiatric Disorders: The Iceberg Still Lies beneath the Surface. Pharmacol Rev 2019; 71:383-412. [PMID: 31243157 DOI: 10.1124/pr.118.015487] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
5-HT3 receptor antagonists, first introduced to the market in the mid-1980s, are proven efficient agents to counteract chemotherapy-induced emesis. Nonetheless, recent investigations have shed light on unappreciated dimensions of this class of compounds in conditions with an immunoinflammatory component as well as in neurologic and psychiatric disorders. The promising findings from multiple studies have unveiled several beneficial effects of these compounds in multiple sclerosis, stroke, Alzheimer disease, and Parkinson disease. Reports continue to uncover important roles for 5-HT3 receptors in the physiopathology of neuropsychiatric disorders, including depression, anxiety, drug abuse, and schizophrenia. This review addresses the potential of 5-HT3 receptor antagonists in neurology- and neuropsychiatry-related disorders. The broad therapeutic window and high compliance observed with these agents position them as suitable prototypes for the development of novel pharmacotherapeutics with higher efficacy and fewer adverse effects.
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Affiliation(s)
- Gohar Fakhfouri
- Department of Psychiatry and Neuroscience, Faculty of Medicine, CERVO Brain Research Centre, Laval University, Quebec, Quebec, Canada (G.F., R.R.); Sensorion SA, Montpellier, France (J.D.-J.); Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran (M.R.Z.); and Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada (J.-M.B.)
| | - Reza Rahimian
- Department of Psychiatry and Neuroscience, Faculty of Medicine, CERVO Brain Research Centre, Laval University, Quebec, Quebec, Canada (G.F., R.R.); Sensorion SA, Montpellier, France (J.D.-J.); Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran (M.R.Z.); and Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada (J.-M.B.)
| | - Jonas Dyhrfjeld-Johnsen
- Department of Psychiatry and Neuroscience, Faculty of Medicine, CERVO Brain Research Centre, Laval University, Quebec, Quebec, Canada (G.F., R.R.); Sensorion SA, Montpellier, France (J.D.-J.); Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran (M.R.Z.); and Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada (J.-M.B.)
| | - Mohammad Reza Zirak
- Department of Psychiatry and Neuroscience, Faculty of Medicine, CERVO Brain Research Centre, Laval University, Quebec, Quebec, Canada (G.F., R.R.); Sensorion SA, Montpellier, France (J.D.-J.); Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran (M.R.Z.); and Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada (J.-M.B.)
| | - Jean-Martin Beaulieu
- Department of Psychiatry and Neuroscience, Faculty of Medicine, CERVO Brain Research Centre, Laval University, Quebec, Quebec, Canada (G.F., R.R.); Sensorion SA, Montpellier, France (J.D.-J.); Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran (M.R.Z.); and Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada (J.-M.B.)
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9
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Skovgård K, Agerskov C, Kohlmeier KA, Herrik KF. The 5-HT3 receptor antagonist ondansetron potentiates the effects of the acetylcholinesterase inhibitor donepezil on neuronal network oscillations in the rat dorsal hippocampus. Neuropharmacology 2018; 143:130-142. [DOI: 10.1016/j.neuropharm.2018.09.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 09/07/2018] [Accepted: 09/11/2018] [Indexed: 11/24/2022]
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10
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Wylie KP, Smucny J, Legget KT, Tregellas JR. Targeting Functional Biomarkers in Schizophrenia with Neuroimaging. Curr Pharm Des 2017; 22:2117-23. [PMID: 26818860 DOI: 10.2174/1381612822666160127113912] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 01/26/2016] [Indexed: 01/09/2023]
Abstract
Many of the most debilitating symptoms for psychiatric disorders such as schizophrenia remain poorly treated. As such, the development of novel treatments is urgently needed. Unfortunately, the costs associated with high failure rates for investigational compounds as they enter clinical trials has led to pharmaceutical companies downsizing or eliminating research programs needed to develop these drugs. One way of increasing the probability of success for investigational compounds is to incorporate alternative methods of identifying biological targets in order to more effectively screen new drugs. A promising method of accomplishing this goal for psychiatric drugs is to use functional magnetic resonance imaging (fMRI). fMRI investigates neural circuits, shedding light on the biology that generates symptoms such as hallucinations. Once identified, relevant neural circuits can be targeted with pharmacologic interventions and the response to these drugs measured with fMRI. This review describes the early use of fMRI in this context, and discusses the alpha7 nicotinic receptor agonist 3-(2,4-dimethoxybenzylidene) anabaseine (DMXB-A), as an example of the potential value of fMRI for psychiatric drug development.
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Affiliation(s)
- Korey P Wylie
- Department of Psychiatry, Anschutz Medical Campus, Bldg. 500, Mail Stop F546, 13001 East 17th Place, Aurora, CO, 80045, USA.
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11
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The current agonists and positive allosteric modulators of α7 nAChR for CNS indications in clinical trials. Acta Pharm Sin B 2017; 7:611-622. [PMID: 29159020 PMCID: PMC5687317 DOI: 10.1016/j.apsb.2017.09.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 08/02/2017] [Accepted: 08/25/2017] [Indexed: 01/06/2023] Open
Abstract
The alpha-7 nicotinic acetylcholine receptor (α7 nAChR), consisting of homomeric α7 subunits, is a ligand-gated Ca2+-permeable ion channel implicated in cognition and neuropsychiatric disorders. Enhancement of α7 nAChR function is considered to be a potential therapeutic strategy aiming at ameliorating cognitive deficits of neuropsychiatric disorders such as Alzheimer's disease (AD) and schizophrenia. Currently, a number of α7 nAChR modulators have been reported and several of them have advanced into clinical trials. In this brief review, we outline recent progress made in understanding the role of the α7 nAChR in multiple neuropsychiatric disorders and the pharmacological effects of α7 nAChR modulators used in clinical trials.
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Key Words
- 5-CSRTT, five-choice serial reaction time task
- 5-HT, serotonin
- ACh, acetylcholine
- AD, Alzheimer's disease
- ADHD, attention deficit hyperactivity disorder
- Acetylcholine
- Alpha7
- Alzheimer's disease
- Aβ, amyloid-β peptide
- CNS, central nervous system
- DMTS, delayed matching-to-sample
- ECD, extracellular domain
- GABA, γ-aminobutyric acid
- Ion channel
- MLA, methyllycaconitine
- NOR, novel object recognition
- PAMs, positive allosteric modulators
- PCP, neonatal phencyclidine
- PD, Parkinson's disease
- PPI, prepulse inhibition
- Positive allosteric modulators
- SAR, structure–activity relationship
- Schizophrenia
- TMD, transmembrane domains
- nAChR
- nAChR, nicotinic acetylcholine receptor
- α-Btx, α-bungarotoxin
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12
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Liu J, Li C, Peng H, Yu K, Tao J, Lin R, Chen L. Electroacupuncture attenuates learning and memory impairment via activation of α7nAChR-mediated anti-inflammatory activity in focal cerebral ischemia/reperfusion injured rats. Exp Ther Med 2017; 14:939-946. [PMID: 28810545 PMCID: PMC5526149 DOI: 10.3892/etm.2017.4622] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 02/10/2017] [Indexed: 01/18/2023] Open
Abstract
Studies have reported that electroacupuncture (EA) may reduce learning and memory impairment following cerebral ischemic injury. However, the precise mechanism of action remains unclear. In the present study, the attenuation of focal cerebral ischemia/reperfusion injury by EA in rats was investigated. EA at the Baihui (DU 20) and Shenting (DU 24) acupoints was demonstrated to significantly improve performance in the Morris water maze task, with shortened latency time and increased frequency of passing the platform. Molecular analysis revealed that EA activated the expression of α7 nicotinic acetylcholine receptors (α7nAChR) in the hippocampus. In addition, EA led to a decreased expression of the microglia/macrophage marker Iba1 and the astrocyte marker glial fibrillary acidic protein in the hippocampus. EA treatment also led to decreased production of the inflammatory cytokines tumor necrosis factor-α and interleukin-1β. Treatment with methyllycaconitine, an α7nAChR antagonist, attenuated the improvement of learning and memory following EA treatment and the inhibitory effects of EA on glial cell activation and inflammatory cytokine production. In conclusion, the findings of the present study demonstrate that EA is able to improve learning and memory function following cerebral ischemic injury via activation of α7nAChR, which significantly decreases the neuroinflammatory response.
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Affiliation(s)
- Jiao Liu
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350108, P.R. China.,Fujian Rehabilitation Tech Co-innovation Center, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Chunyan Li
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350108, P.R. China
| | - Hongwei Peng
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350108, P.R. China
| | - Kunqiang Yu
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350108, P.R. China
| | - Jing Tao
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350108, P.R. China
| | - Ruhui Lin
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350108, P.R. China.,Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Lidian Chen
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350108, P.R. China
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13
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Kunisawa N, Iha HA, Nomura Y, Onishi M, Matsubara N, Shimizu S, Ohno Y. Serotonergic modulation of nicotine-induced kinetic tremor in mice. J Pharmacol Sci 2017. [DOI: 10.1016/j.jphs.2017.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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14
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Callahan PM, Bertrand D, Bertrand S, Plagenhoef MR, Terry AV. Tropisetron sensitizes α7 containing nicotinic receptors to low levels of acetylcholine in vitro and improves memory-related task performance in young and aged animals. Neuropharmacology 2017; 117:422-433. [PMID: 28259598 DOI: 10.1016/j.neuropharm.2017.02.025] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 02/06/2017] [Accepted: 02/25/2017] [Indexed: 01/02/2023]
Abstract
Tropisetron, a 5-HT3 receptor antagonist commonly prescribed for chemotherapy-induced nausea and vomiting also exhibits high affinity, partial agonist activity at α7 nicotinic acetylcholine receptors (α7 nAChRs). α7 nAChRs are considered viable therapeutic targets for neuropsychiatric disorders such as Alzheimer's disease (AD). Here we further explored the nAChR pharmacology of tropisetron to include the homomeric α7 nAChR and recently characterized heteromeric α7β2 nAChR (1:10 ratio) and we evaluated its cognitive effects in young and aged animals. Electrophysiological studies on human nAChRs expressed in Xenopus oocytes confirmed the partial agonist activity of tropisetron at α7 nAChRs (EC50 ∼2.4 μM) with a similar effect at α7β2 nAChRs (EC50 ∼1.5 μM). Moreover, currents evoked by irregular pulses of acetylcholine (40 μM) at α7 and α7β2 nAChRs were enhanced during sustained exposure to low concentrations of tropisetron (10 and 30 nM) indicative of a "priming" or co-agonist effect. Tropisetron (0.1-10 mg/kg) improved novel object recognition performance in young Sprague-Dawley rats and in aged Fischer rats. In aged male and female rhesus monkeys, tropisetron (0.03-1 mg/kg) produced a 17% increase from baseline levels in delayed match to sample long delay accuracy while combination of non-effective doses of donepezil (0.1 mg/kg) and tropisetron (0.03 and 0.1 mg/kg) produced a 24% change in accuracy. Collectively, these animal experiments indicate that tropisetron enhances cognition and has the ability to improve the effective dose range of currently prescribed AD therapy (donepezil). Moreover, these effects may be explained by tropisetron's ability to sensitize α7 containing nAChRs to low levels of acetylcholine.
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Affiliation(s)
- Patrick M Callahan
- Department of Pharmacology and Toxicology, Augusta University, Augusta, GA 30912, United States.
| | - Daniel Bertrand
- HiQScreen Sàrl, 6, rte de Compois, 1222 Vésenaz, Geneva, Switzerland
| | - Sonia Bertrand
- HiQScreen Sàrl, 6, rte de Compois, 1222 Vésenaz, Geneva, Switzerland
| | - Marc R Plagenhoef
- Department of Pharmacology and Toxicology, Augusta University, Augusta, GA 30912, United States
| | - Alvin V Terry
- Department of Pharmacology and Toxicology, Augusta University, Augusta, GA 30912, United States
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15
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Potasiewicz A, Hołuj M, Kos T, Popik P, Arias HR, Nikiforuk A. 3-Furan-2-yl-N-p-tolyl-acrylamide, a positive allosteric modulator of the α7 nicotinic receptor, reverses schizophrenia-like cognitive and social deficits in rats. Neuropharmacology 2017; 113:188-197. [DOI: 10.1016/j.neuropharm.2016.10.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 06/20/2016] [Accepted: 10/01/2016] [Indexed: 12/19/2022]
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16
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Stoiljkovic M, Kelley C, Nagy D, Leventhal L, Hajós M. Selective activation of α7 nicotinic acetylcholine receptors augments hippocampal oscillations. Neuropharmacology 2016; 110:102-108. [PMID: 27422408 DOI: 10.1016/j.neuropharm.2016.07.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 05/26/2016] [Accepted: 07/10/2016] [Indexed: 01/09/2023]
Abstract
Neural α7 nicotinic acetylcholine receptors (α7 nAChRs) emerged as a potential pharmacologic target for treating cognitive deficits in schizophrenia and Alzheimer's disease. Experiments modeling these dysfunctions, as well as clinical evidence, demonstrate the relatively consistent procognitive effects of α7 nAChR agonists. One preclinical observation supporting the procognitive role of α7 nAChRs is their ability to modulate neuronal network oscillations closely associated with learning and memory, especially hippocampal oscillations. Due to the high degree of structural similarity between α7 nACh and 5-HT receptors, the majority of α7 nAChR agonists to date also act as 5-HT3 antagonists. To address this confounding property and determine the relevance of α7 nAChR agonist binding to 5-HT3 receptors in modulating hippocampal activity, we tested two well-described α7 nAChR agonists, PNU-282987 and FRM-17874, in mice lacking α7 nAChRs (α7 knock-out, α7KO) using the brainstem simulation-elicited hippocampal theta oscillation assay. Under urethane anesthesia both agonists at equivalent doses demonstrated efficacy in wild-type (WT) mice, significantly enhancing theta power and theta phase-gamma amplitude coupling as compared to saline treated control mice. These effects are comparable to those seen with drugs clinically used to treat Alzheimer's disease. Although α7KO mice showed no alterations in elicited hippocampal oscillations, both α7 nAChR agonists failed to enhance theta power or theta phase - gamma amplitude coupling in these mice. Our findings demonstrate that selective activation of α7 nAChRs can modulate hippocampal oscillation, and these receptors are the primary targets of the tested agonists, PNU-282987 and FRM-17874 and likely underlies their observed procognitive activity.
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Affiliation(s)
- Milan Stoiljkovic
- Translational Neuropharmacology, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Craig Kelley
- Translational Neuropharmacology, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Dávid Nagy
- Translational Neuropharmacology, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT, 06520, USA
| | | | - Mihály Hajós
- Translational Neuropharmacology, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT, 06520, USA.
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17
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Goetghebeur PJ, Swartz JE. True alignment of preclinical and clinical research to enhance success in CNS drug development: a review of the current evidence. J Psychopharmacol 2016; 30:586-94. [PMID: 27147593 DOI: 10.1177/0269881116645269] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Central nervous system pharmacological research and development has reached a critical turning point. Patients suffering from disorders afflicting the central nervous system are numerous and command significant attention from the pharmaceutical industry. However, given the numerous failures of promising drugs, many companies are no longer investing in or, indeed, are divesting from this therapeutic area. Central nervous system drug development must change in order to develop effective therapies to treat these patients. Preclinical research is a cornerstone of drug development; however, it is frequently criticised for its lack of predictive validity. Animal models and assays can be shown to be more predictive than reported and, on many occasions, the lack of thorough preclinical testing is potentially to blame for some of the clinical failures. Important factors such as translational aspects, nature of animal models, variances in acute versus chronic dosing, development of add-on therapies and understanding of the full dose-response relationship are too often neglected. Reducing the attrition rate in central nervous system drug development could be achieved by addressing these important questions before novel compounds enter the clinical phase. This review illustrates the relevance of employing these criteria to translational central nervous system research, better to ensure success in developing new drugs in this therapeutic area.
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Affiliation(s)
| | - Jina E Swartz
- CNS Therapeutic Area Unit, Takeda Development Centre Europe Ltd, London, UK
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18
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Gupta D, Prabhakar V, Radhakrishnan M. 5HT3 receptors: Target for new antidepressant drugs. Neurosci Biobehav Rev 2016; 64:311-25. [PMID: 26976353 DOI: 10.1016/j.neubiorev.2016.03.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Revised: 02/29/2016] [Accepted: 03/01/2016] [Indexed: 12/31/2022]
Abstract
5HT3 receptors (5HT3Rs) have long been identified as a potential target for antidepressants. Several studies have reported that antagonism of 5HT3Rs produces antidepressant-like effects. However, the exact role of 5HT3Rs and the mode of antidepressant action of 5HT3R antagonists still remain a mystery. Here, we provide a comprehensive overview of 5HT3Rs: (a) regional and subcellular distribution of 5HT3Rs in discrete brain regions, (b) preclinical and clinical evidence supporting the antidepressant effect of 5HT3R antagonists, and (c) neurochemical, biological and neurocellular signaling pathways associated with the antidepressant action of 5HT3R antagonists. 5HT3Rs located on the serotonergic and other neurotransmitter interneuronal projections control their release and affect mood and emotional behavior; however, new evidence suggests that apart from modulating the neurotransmitter functions, 5HT3R antagonists have protective effects in the pathogenic events including hypothalamic-pituitary-adrenal-axis hyperactivity, brain oxidative stress and impaired neuronal plasticity, pointing to hereby unknown and novel mechanisms of their antidepressant action. Nonetheless, further investigations are warranted to establish the exact role of 5HT3Rs in depression and antidepressant action of 5HT3R antagonists.
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Affiliation(s)
- Deepali Gupta
- Department of Pharmacy, Birla Institute of Technology and Science, Pilani, Rajasthan 333031, India.
| | - Visakh Prabhakar
- Department of Pharmacy, Birla Institute of Technology and Science, Pilani, Rajasthan 333031, India.
| | - Mahesh Radhakrishnan
- Department of Pharmacy, Birla Institute of Technology and Science, Pilani, Rajasthan 333031, India.
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19
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Bertrand D, Lee CHL, Flood D, Marger F, Donnelly-Roberts D. Therapeutic Potential of α7 Nicotinic Acetylcholine Receptors. Pharmacol Rev 2015; 67:1025-73. [DOI: 10.1124/pr.113.008581] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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20
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Jaikhan P, Boonyarat C, Arunrungvichian K, Taylor P, Vajragupta O. Design and Synthesis of Nicotinic Acetylcholine Receptor Antagonists and their Effect on Cognitive Impairment. Chem Biol Drug Des 2015; 87:39-56. [DOI: 10.1111/cbdd.12627] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/03/2015] [Accepted: 07/15/2015] [Indexed: 12/13/2022]
Affiliation(s)
- Pattaporn Jaikhan
- Center of Excellence for Innovation in Drug Design and Discovery; Faculty of Pharmacy; Mahidol University; 447 Sri-Ayudya Road Bangkok 10400 Thailand
| | - Chantana Boonyarat
- Department of Pharmaceutical Chemistry; Faculty of Pharmaceutical Science; KhonKaen University; KhonKaen 4000 Thailand
| | - Kuntarat Arunrungvichian
- Center of Excellence for Innovation in Drug Design and Discovery; Faculty of Pharmacy; Mahidol University; 447 Sri-Ayudya Road Bangkok 10400 Thailand
- Department of Pharmacology; Skaggs School of Pharmacy and Pharmaceutical Sciences; University of California; San Diego 9500 Gilman Drive La Jolla CA 92093-0657 USA
| | - Palmer Taylor
- Department of Pharmacology; Skaggs School of Pharmacy and Pharmaceutical Sciences; University of California; San Diego 9500 Gilman Drive La Jolla CA 92093-0657 USA
| | - Opa Vajragupta
- Center of Excellence for Innovation in Drug Design and Discovery; Faculty of Pharmacy; Mahidol University; 447 Sri-Ayudya Road Bangkok 10400 Thailand
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21
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Nicotinic ligands as multifunctional agents for the treatment of neuropsychiatric disorders. Biochem Pharmacol 2015; 97:388-398. [PMID: 26231940 DOI: 10.1016/j.bcp.2015.07.027] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 07/24/2015] [Indexed: 02/08/2023]
Abstract
The challenges associated with developing more effective treatments for neurologic and psychiatric illness such as Alzheimer's disease and schizophrenia are considerable. Both the symptoms and the pathophysiology of these conditions are complex and poorly understood and the clinical presentations across different patients can be very heterogeneous. Moreover, it has become apparent that the reductionist approach to drug discovery for these illnesses that has dominated the field for decades (i.e., the development of highly selective compounds or other treatment modalities focused on a very specific pathophysiologic target) has not been widely successful. Accordingly, a variety of new strategies have emerged including the development of "multitarget-directed ligands" (MTDLs), the development and/or identification of compounds that exhibit "multifunctional" activity (e.g., pro-cognitive plus neuroprotective, pro-cognitive plus antipsychotic activity), "repurposing" strategies for existing compounds that have other clinical indications, and novel "adjunctive" treatment strategies that might enhance the efficacy of the currently available treatments. Interestingly, a variety of ligands at nicotinic acetylcholine receptors (nAChRs) appear to have the potential to fulfill one or more of these desirable properties (i.e., multifunctional, repurposing, or adjunctive treatment potential). The purpose of this review (while not all-inclusive) is to provide an overview of a variety of nAChR ligands that demonstrate potential in these categories, particularly, "multifunctional" properties. Due to their densities in the mammalian brain and the amount of literature available, the review will focus on ligands of the high affinity α4β2 nAChR and the low affinity α7 nAChR.
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22
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Leiser SC, Li Y, Pehrson AL, Dale E, Smagin G, Sanchez C. Serotonergic Regulation of Prefrontal Cortical Circuitries Involved in Cognitive Processing: A Review of Individual 5-HT Receptor Mechanisms and Concerted Effects of 5-HT Receptors Exemplified by the Multimodal Antidepressant Vortioxetine. ACS Chem Neurosci 2015; 6:970-86. [PMID: 25746856 DOI: 10.1021/cn500340j] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
It has been known for several decades that serotonergic neurotransmission is a key regulator of cognitive function, mood, and sleep. Yet with the relatively recent discoveries of novel serotonin (5-HT) receptor subtypes, as well as an expanding knowledge of their expression level in certain brain regions and localization on certain cell types, their involvement in cognitive processes is still emerging. Of particular interest are cognitive processes impacted in neuropsychiatric and neurodegenerative disorders. The prefrontal cortex (PFC) is critical to normal cognitive processes, including attention, impulsivity, planning, decision-making, working memory, and learning or recall of learned memories. Furthermore, serotonergic dysregulation within the PFC is implicated in many neuropsychiatric disorders associated with prominent symptoms of cognitive dysfunction. Thus, it is important to better understand the overall makeup of serotonergic receptors in the PFC and on which cell types these receptors mediate their actions. In this Review, we focus on 5-HT receptor expression patterns within the PFC and how they influence cognitive behavior and neurotransmission. We further discuss the net effects of vortioxetine, an antidepressant acting through multiple serotonergic targets given the recent findings that vortioxetine improves cognition by modulating multiple neurotransmitter systems.
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Affiliation(s)
| | - Yan Li
- Lundbeck Research USA, Paramus, New Jersey 07650, United States
| | - Alan L. Pehrson
- Lundbeck Research USA, Paramus, New Jersey 07650, United States
| | - Elena Dale
- Lundbeck Research USA, Paramus, New Jersey 07650, United States
| | - Gennady Smagin
- Lundbeck Research USA, Paramus, New Jersey 07650, United States
| | - Connie Sanchez
- Lundbeck Research USA, Paramus, New Jersey 07650, United States
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23
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The novel α7 nicotinic acetylcholine receptor agonist EVP-6124 enhances dopamine, acetylcholine, and glutamate efflux in rat cortex and nucleus accumbens. Psychopharmacology (Berl) 2014; 231:4541-51. [PMID: 24810107 DOI: 10.1007/s00213-014-3596-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 04/20/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Alpha7 and α4β2 nicotinic acetylcholine receptor (nAChR) agonists have been shown to improve cognition in various animal models of cognitive impairment and are of interest as treatments for schizophrenia, Alzheimer's disease, and other cognitive disorders. Increased release of dopamine (DA), acetylcholine (ACh), glutamate (Glu), and γ-aminobutyric acid (GABA) in cerebral cortex, hippocampus, and nucleus accumbens (NAC) has been suggested to contribute to their beneficial effects on cognition. RESULTS Using in vivo microdialysis, we found that EVP-6124 [(R)-7-chloro-N-quinuclidin-3-yl)benzo[b]thiophene-2-carboxamide], a high-affinity α7 nAChR partial agonist, at 0.1 mg/kg, s.c., increased DA efflux in the medial prefrontal cortex (mPFC) and NAC. EVP-6124, 0.1 and 0.3 mg/kg, also increased efflux of ACh in the mPFC but not in the NAC. Similarly, EVP-6124, 0.1 mg/kg, but not 0.03 and 0.3 mg/kg, significantly increased mPFC Glu efflux. Thus, EVP-6124 produced an inverted U-shaped curve for DA and Glu release, as previously reported for other α7 nAChR agonists. The three doses of EVP-6124 did not produce a significant effect on GABA efflux in either region. Pretreatment with the selective α7 nAChR antagonist, methyllycaconitine (MLA, 1.0 mg/kg), significantly blocked cortical DA and Glu efflux induced by EVP-6124 (0.1 mg/kg), suggesting that the effects of EVP-6124 on these neurotransmitters were due to α7 nAChR agonism. MLA only partially blocked the effects of EVP-6124 on ACh efflux in the mPFC. CONCLUSION These results suggest increased cortical DA, ACh, and Glu release, which may contribute to the ability of the α7 nAChR agonist, EVP-6124, to treat cognitive impairment and possibly other dimensions of psychopathology.
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Teodoro R, Wenzel B, Oh-Nishi A, Fischer S, Peters D, Suhara T, Deuther-Conrad W, Brust P. A high-yield automated radiosynthesis of the alpha-7 nicotinic receptor radioligand [ 18F]NS10743. Appl Radiat Isot 2014; 95:76-84. [PMID: 25464181 DOI: 10.1016/j.apradiso.2014.09.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 09/16/2014] [Accepted: 09/29/2014] [Indexed: 01/30/2023]
Abstract
[18F]NS10743, a promising and highly competitive α7 nAChR radioligand has been synthesized so far by microwave irradiation using a manual single-mode device followed by a palladium-catalyzed reduction of remaining nitro-precursor for HPLC separation purposes. For further preclinical and clinical use, regulated production of [18F]NS10743 by fully automated radiosynthesis is a crucial requirement. Therefore, we chose a commercial synthesis module and developed the automated radiosynthesis of [18F]NS10743. Besides evaluation of several radiosynthesis procedures, we performed an extensive HPLC study for quantitative separation of [18F]NS10743 from the corresponding nitro precursor. After implementation of the optimized procedure on a TRACERlabTM FX F-N synthesis module, [18F]NS10743 was obtained in high radiochemical purity (≥99%) with an overall radiochemical yield of 32.2±7% (n=3). The specific activities at the end of the synthesis were 571±17GBq/µmol (n=3).
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Affiliation(s)
- Rodrigo Teodoro
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Germany.
| | - Barbara Wenzel
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Germany
| | - Arata Oh-Nishi
- Molecular Neuroimaging Program, Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba, Japan
| | - Steffen Fischer
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Germany
| | | | - Tetsuya Suhara
- Molecular Neuroimaging Program, Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba, Japan
| | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Germany
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, Germany
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