1
|
Boopathi S, Haridevamuthu B, Gandhi A, Nayak SPRR, Sudhakaran G, Rajagopal R, Arokiyaraj S, Arockiaraj J. Neurobehavioral impairments from chromium exposure: Insights from a zebrafish model and drug validation. Comp Biochem Physiol C Toxicol Pharmacol 2024; 275:109780. [PMID: 37884255 DOI: 10.1016/j.cbpc.2023.109780] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/15/2023] [Accepted: 10/23/2023] [Indexed: 10/28/2023]
Abstract
We have developed a zebrafish model to explore the alterations in neurobehaviors resulting from both acute and chronic exposure to chromium (Cr). Zebrafish exposed to half (HC group: 19.7 mg/L) and a quarter (LC group: 9.85 mg/L) of the LD50 concentration of Cr for a span of 2 weeks exhibited aberrant locomotion, heightened anxiety, cognitive impairment, and reduced aggression - hallmark traits reminiscent of an Alzheimer's Disease (AD)-like syndrome. Furthermore, zebrafish exposed to an environmentally relevant concentration of Cr (EC group: 100 μg/L) for an extended period of 9 weeks exhibited behaviors comparable to those observed in the HC group. Moreover, the study investigated the neuroprotective effects of donepezil (Don), galantamine (Gal) and resveratrol (Res) drugs in response to neurobehavioral impairments induced by Cr (VI) exposure in zebrafish. Don and Res effectively protect the zebrafish from Cr (VI)-induced anxiety, and memory impairment. Furthermore, Cr (VI) exposure induced heightened oxidative stress while simultaneously diminishing antioxidant enzyme levels. Remarkably, these effects were counteracted in the drug-treated groups. Likewise, exposure to Cr (VI) led to an increase in the expression of genes linked to AD and neuroinflammation. Nevertheless, drug treatment reversed this effect in Cr (VI)-exposed fish. The results of our study highlight the potentials of zebrafish model in demonstrating neurobehavioral impairments induced by Cr (VI), thereby paving the way for its utilization in vivo neurobehaviors investigations and pharmaceutical screening.
Collapse
Affiliation(s)
- Seenivasan Boopathi
- Toxicology and Pharmacology Laboratory, Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Kattankulathur 603203, Chengalpattu District, Tamil Nadu, India. https://twitter.com/@iamboopathi
| | - B Haridevamuthu
- Toxicology and Pharmacology Laboratory, Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Kattankulathur 603203, Chengalpattu District, Tamil Nadu, India
| | - Akash Gandhi
- Toxicology and Pharmacology Laboratory, Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Kattankulathur 603203, Chengalpattu District, Tamil Nadu, India
| | - S P Ramya Ranjan Nayak
- Toxicology and Pharmacology Laboratory, Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Kattankulathur 603203, Chengalpattu District, Tamil Nadu, India
| | - Gokul Sudhakaran
- Toxicology and Pharmacology Laboratory, Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Kattankulathur 603203, Chengalpattu District, Tamil Nadu, India
| | - Rajakrishnan Rajagopal
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Selvaraj Arokiyaraj
- Department of Food Science & Biotechnology, Sejong University, Seoul 05006, Republic of Korea
| | - Jesu Arockiaraj
- Toxicology and Pharmacology Laboratory, Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Kattankulathur 603203, Chengalpattu District, Tamil Nadu, India.
| |
Collapse
|
2
|
Physiologic Functions and Therapeutic Applications of α7 Nicotinic Acetylcholine Receptor in Brain Disorders. Pharmaceutics 2022; 15:pharmaceutics15010031. [PMID: 36678660 PMCID: PMC9865019 DOI: 10.3390/pharmaceutics15010031] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/13/2022] [Accepted: 12/17/2022] [Indexed: 12/25/2022] Open
Abstract
Accumulating data suggest that α7 nicotinic acetylcholine receptors (α7nAChRs) are an important therapeutic target for the treatment of Alzheimer's disease (AD) and schizophrenia. The homopentameric ligand-gated ion channel α7nAChR consists of five identical α7 subunits that are encoded by the CHRNA7 (cholinergic receptor nicotinic alpha7 subunit) gene. Moreover, α7nAChRs are densely distributed throughout the hippocampus, cortex, and thalamus brain regions, but sparsely in the striatum, forebrain, and medulla. Compared with other nAChRs, α7nAChR binds with low affinity to the naturally occurring neurotransmitter acetylcholine and the non-specific exogenous agonist nicotine, and with high affinity to the specific antagonists α-bungarotoxin and methyllycaconitine. Reports indicate that α7nAChR plays important roles in neurotransmitter release, cognitive functioning, and the cholinergic anti-inflammatory response. Genetic variations that alter CHRNA7 mRNA and protein expression or cause α7nAChR dysfunction are associated with many brain disorders. Our previous studies revealed that α7nAChR exerts neuroprotection in AD by acting as a cargo receptor for binding the autophagosomal marker protein LC3 and engulfing extracellular neurotoxic Aβ1-42 during autophagic degradation of the α7nAChR-Aβ1-42 complex. However, the role of α7nAChRs in other diseases remains unknown. Here, we review and summarize the essential characteristics and current findings concerning α7nAChRs in four common brain diseases (AD, Parkinson's disease, schizophrenia, and depression), which may elucidate the role of α7nAChRs and inform innovative research and novel treatments that target α7nAChRs in brain disease.
Collapse
|
3
|
Galantamine tethered hydrogel as a novel therapeutic target for streptozotocin-induced Alzheimer's disease in Wistar rats. CURRENT RESEARCH IN PHARMACOLOGY AND DRUG DISCOVERY 2022; 3:100100. [PMID: 35510084 PMCID: PMC9058960 DOI: 10.1016/j.crphar.2022.100100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 04/05/2022] [Accepted: 04/13/2022] [Indexed: 01/20/2023] Open
Abstract
Amyloid-β (Aβ) plaque formation, neuronal cell death, and cognitive impairment are the unique symptoms of Alzheimer's disease (AD). No single step remedy is available to treat AD, so the present study aimed to improve the drugability and minimize the abnormal behavioral and biochemical activities in streptozotocin (STZ) induced AD experimental Wistar rats. In particular, we explored the utilization of methacrylated gelatin (GelMA), which is a biopolymeric hydrogel that mimics the natural tissue environment. The synthesized biopolymeric gel contained the drug galantamine (Gal). Investigations were conducted to evaluate the behavioral activities of STZ-induced AD experimental rats under STZ + GelMA + Gal treatment. The experimental groups comprised the control and STZ, STZ + GelMA, STZ + Gal, and STZ + GelMA + Gal (10 mg/kg) treated rats. Intracerebroventricular STZ ensures cognitive decline in terms of an increase in the escape latency period, with a decrease in the spontaneous alteration of behavioral activities. Our results indicated decrease Aβ aggregation in the hydrogel-based drug treatment group and significant decreases in the levels of acetylcholinesterase and lipid peroxidation (p < 0.001). In addition, the glutathione and superoxide dismutase activities appeared to be improved in the STZ + GelMA + Gal group compared with the other treatment groups. Furthermore, histopathological and immunohistochemical experiments showed that the GelMA + Gal treated AD rats exhibited significantly improved behavioral and biochemical activities compared with the STZ treated AD rats. Therefore, STZ + GelMA + Gal administration from the pre-plaque stage may have a potential clinical application in the prevention of AD. Thus, we conclude that hydrogel-based Gal drugs are efficient at decreasing Aβ aggregation and improving the neuroinflammatory process, antioxidant activity, and neuronal growth. Hydrogel-based drug treatment normalized cognitive deficit sin ICV-STZ rats with AD. Hydrogel-based drug treatment enhanced behavioral and biochemical activities in AD-induced rats. Hydrogel-based drug treatment increased memory performance and neuronal growth in rats with AD. Antioxidant potential of hydrogel-tethered Gal blocked apoptosis in AD-induced rats.
Collapse
|
4
|
Magdy S, Gamal M, Samir NF, Rashed L, Emad Aboulhoda B, Mohammed HS, Sharawy N. IκB kinase inhibition remodeled connexins, pannexin-1, and excitatory amino-acid transporters expressions to promote neuroprotection of galantamine and morphine. J Cell Physiol 2021; 236:7516-7532. [PMID: 33855721 DOI: 10.1002/jcp.30387] [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: 07/02/2020] [Revised: 03/21/2021] [Accepted: 03/26/2021] [Indexed: 11/10/2022]
Abstract
Inflammatory pathway and disruption in glutamate homeostasis join at the level of the glia, resulting in various neurological disorders. In vitro studies have provided evidence that membrane proteins connexions (Cxs) are involved in glutamate release, meanwhile, excitatory amino-acid transporters (EAATs) are crucial for glutamate reuptake (clearance). Moreover, pannexin-1 (Panx-1) activation is more detrimental to neurons. Their expression patterns during inflammation and the impacts of IκB kinase (IKK) inhibition, morphine, and galantamine on the inflammatory-associated glutamate imbalance remain elusive. To investigate this, rats were injected with saline or lipopolysaccharide. Thereafter, vehicles, morphine, galantamine, and BAY-117082 were administered in different groups of animals. Subsequently, electroencephalography, enzyme-linked immunosorbent assay, western blot, and histopathological examinations were carried out and various indicators of inflammation and glutamate level were determined. Parallel analysis of Cxs, Panx-1, and EAAts in the brain was performed. Our findings strengthen the concept that unregulated expressions of Cxs, Panx-1, and EAATs contribute to glutamate accumulation and neuronal cell loss. Nuclear factor-kB (NF-κB) pathway can significantly contribute to glutamate homeostasis via modulating Cxs, Panx-1, and EAATs expressions. BAY-117082, via inhibition of IkK, promoted the anti-inflammatory effects of morphine as well as galantamine. We concluded that NF-κB is an important component of reshaping the expressions of Cxs, panx-1, and EAATs and the development of glutamate-induced neuronal degeneration.
Collapse
Affiliation(s)
- Shimaa Magdy
- Department of Physiology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Maha Gamal
- Department of Physiology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Nancy F Samir
- Department of Physiology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Laila Rashed
- Department of Biochemistry, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Basma Emad Aboulhoda
- Department of Anatomy and Embryology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Haitham S Mohammed
- Department of Biophysics, Faculty of Science, Cairo University, Giza, Egypt
| | - Nivin Sharawy
- Department of Physiology, Faculty of Medicine, Cairo University, Cairo, Egypt
| |
Collapse
|
5
|
Mori Y, Mouri A, Kunisawa K, Hirakawa M, Kubota H, Kosuge A, Niijima M, Hasegawa M, Kurahashi H, Murakami R, Hoshi M, Nakano T, Fujigaki S, Fujigaki H, Yamamoto Y, Nabeshima T, Saito K. Kynurenine 3-monooxygenase deficiency induces depression-like behavior via enhanced antagonism of α7 nicotinic acetylcholine receptors by kynurenic acid. Behav Brain Res 2021; 405:113191. [PMID: 33607168 DOI: 10.1016/j.bbr.2021.113191] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 02/03/2021] [Accepted: 02/10/2021] [Indexed: 01/09/2023]
Abstract
Tryptophan (TRP) is metabolized via the kynurenine (KYN) pathway, which is related to the pathogenesis of major depressive disorder (MDD). Kynurenine 3-monooxygenase (KMO) is a pivotal enzyme in the metabolism of KYN to 3-hydroxykynurenine. In rodents, KMO deficiency induces a depression-like behavior and increases the levels of kynurenic acid (KA), a KYN metabolite formed by kynurenine aminotransferases (KATs). KA antagonizes α7 nicotinic acetylcholine receptor (α7nAChR). Here, we investigated the involvement of KA in depression-like behavior in KMO knockout (KO) mice. KYN, KA, and anthranilic acid but not TRP or 3-hydroxyanthranilic acid were elevated in the prefrontal cortex of KMO KO mice. The mRNA levels of KAT1 and α7nAChR but not KAT2-4, α4nAChR, or β2nAChR were elevated in the prefrontal cortex of KMO KO mice. Nicotine blocked increase in locomotor activity, decrease in social interaction time, and prolonged immobility in a forced swimming test, but it did not decrease sucrose preference in the KMO KO mice. Methyllycaconitine (an α7nAChR antagonist) antagonized the effect of nicotine on decreased social interaction time and prolonged immobility in the forced swimming test, but not increased locomotor activity. Galantamine (an α7nAChR allosteric agonist) blocked the increased locomotor activity and prolonged immobility in the forced swimming test, but not the decreased social interaction time in the KMO KO mice. In conclusion, elevation of KA levels contributes to depression-like behaviors in KMO KO mice by α7nAChR antagonism. The ameliorating effects of nicotine and galantamine on depression-like behaviors in KMO KO mice are associated with the activation of α7nAChR.
Collapse
Affiliation(s)
- Yuko Mori
- Department of Disease Control and Prevention, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Akihiro Mouri
- Department of Regulatory Science for Evaluation & Development of Pharmaceuticals & Devices, Fujita Health University Graduate School of Health Science, Aichi, Japan; Japanese Drug Organization of Appropriate Use and Research, Aichi, Japan.
| | - Kazuo Kunisawa
- Department of Regulatory Science for Evaluation & Development of Pharmaceuticals & Devices, Fujita Health University Graduate School of Health Science, Aichi, Japan; Advanced Diagnostic System Research Laboratory, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Mami Hirakawa
- Department of Regulatory Science for Evaluation & Development of Pharmaceuticals & Devices, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Hisayoshi Kubota
- Department of Regulatory Science for Evaluation & Development of Pharmaceuticals & Devices, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Aika Kosuge
- Department of Regulatory Science for Evaluation & Development of Pharmaceuticals & Devices, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Moe Niijima
- Department of Regulatory Science for Evaluation & Development of Pharmaceuticals & Devices, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Masaya Hasegawa
- Department of Regulatory Science for Evaluation & Development of Pharmaceuticals & Devices, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Hitomi Kurahashi
- Department of Regulatory Science for Evaluation & Development of Pharmaceuticals & Devices, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Reiko Murakami
- Department of Disease Control and Prevention, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Masato Hoshi
- Department of Disease Control and Prevention, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Takashi Nakano
- Department of Computational Biology, School of Medicine, Fujita Health University, Aichi, Japan
| | - Suwako Fujigaki
- Department of Disease Control and Prevention, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Hidetsugu Fujigaki
- Department of Disease Control and Prevention, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Yasuko Yamamoto
- Department of Disease Control and Prevention, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Toshitaka Nabeshima
- Advanced Diagnostic System Research Laboratory, Fujita Health University Graduate School of Health Science, Aichi, Japan; Japanese Drug Organization of Appropriate Use and Research, Aichi, Japan
| | - Kuniaki Saito
- Department of Disease Control and Prevention, Fujita Health University Graduate School of Health Science, Aichi, Japan; Japanese Drug Organization of Appropriate Use and Research, Aichi, Japan
| |
Collapse
|
6
|
Evidence for positive allosteric modulation of cognitive-enhancing effects of nicotine by low-dose galantamine in rats. Pharmacol Biochem Behav 2020; 199:173043. [PMID: 33022302 DOI: 10.1016/j.pbb.2020.173043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 09/28/2020] [Accepted: 09/29/2020] [Indexed: 11/22/2022]
Abstract
Cognitive-enhancing effects of nicotinic acetylcholine receptor (nAChR) agonists may be of therapeutic potential in disease states characterized by nAChR hypofunction; however, effects tend to be of small magnitude and unlikely clinical significance. The co-administration of a nAChR positive allosteric modulator (PAM) may enable larger effects by potentiating nAChR responses to an agonist. The acetylcholinesterase (AChE) inhibitor galantamine is a nAChR PAM at a low dose range. A recent clinical study testing effects of a single small dose of galantamine found evidence for synergistic effects with nicotine on one of several cognitive measures. In that study, residual AChE inhibition may have obscured interactions on other measures. The present study aimed at examining small galantamine doses devoid of AChE inhibitory activity in a rodent model of attention. The effects of galantamine (0.03-0.25 mg/kg s.c.) were tested in the presence and absence of nicotine (0.1 mg/kg s.c.) in rats performing the 5-Choice Serial Reaction Time Task, employing a within-subject factorial design. There were no effects on response accuracy of either nicotine or galantamine alone. However, the combination of nicotine and 0.06 mg/kg of galantamine significantly enhanced accuracy. AChE activity assays confirmed that, at this dose, galantamine was devoid of AChE inhibitory activity in the brain. The results suggest that cognitive-enhancing effects of nicotine may be potentiated or uncovered by an extremely small dose of galantamine, well below its typical therapeutic range in humans. Furthermore, these findings provide a general proof-of-principle for a nAChR agonist and PAM combination strategy for cognitive enhancement.
Collapse
|
7
|
Marotta G, Basagni F, Rosini M, Minarini A. Memantine Derivatives as Multitarget Agents in Alzheimer's Disease. Molecules 2020; 25:molecules25174005. [PMID: 32887400 PMCID: PMC7504780 DOI: 10.3390/molecules25174005] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/31/2020] [Accepted: 09/01/2020] [Indexed: 12/24/2022] Open
Abstract
Memantine (3,5-dimethyladamantan-1-amine) is an orally active, noncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist approved for treatment of moderate-to-severe Alzheimer’s disease (AD), a neurodegenerative condition characterized by a progressive cognitive decline. Unfortunately, memantine as well as the other class of drugs licensed for AD treatment acting as acetylcholinesterase inhibitors (AChEIs), provide only symptomatic relief. Thus, the urgent need in AD drug development is for disease-modifying therapies that may require approaching targets from more than one path at once or multiple targets simultaneously. Indeed, increasing evidence suggests that the modulation of a single neurotransmitter system represents a reductive approach to face the complexity of AD. Memantine is viewed as a privileged NMDAR-directed structure, and therefore, represents the driving motif in the design of a variety of multi-target directed ligands (MTDLs). In this review, we present selected examples of small molecules recently designed as MTDLs to contrast AD, by combining in a single entity the amantadine core of memantine with the pharmacophoric features of known neuroprotectants, such as antioxidant agents, AChEIs and Aβ-aggregation inhibitors.
Collapse
|
8
|
Wulaer B, Kunisawa K, Hada K, Jaya Suento W, Kubota H, Iida T, Kosuge A, Nagai T, Yamada K, Nitta A, Yamamoto Y, Saito K, Mouri A, Nabeshima T. Shati/Nat8l deficiency disrupts adult neurogenesis and causes attentional impairment through dopaminergic neuronal dysfunction in the dentate gyrus. J Neurochem 2020; 157:642-655. [PMID: 32275776 DOI: 10.1111/jnc.15022] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 03/25/2020] [Accepted: 03/25/2020] [Indexed: 12/18/2022]
Abstract
Successful completion of daily activities relies on the ability to select the relevant features of the environment for memory and recall. Disruption to these processes can lead to various disorders, such as attention-deficit hyperactivity disorder (ADHD). Dopamine is a neurotransmitter implicated in the regulation of several processes, including attention. In addition to the higher-order brain function, dopamine is implicated in the regulation of adult neurogenesis. Previously, we generated mice lacking Shati, an N-acetyltransferase-8-like protein on a C57BL/6J genetic background (Shati/Nat8l-/- ). These mice showed a series of changes in the dopamine system and ADHD-like behavioral phenotypes. Therefore, we hypothesized that deficiency of Shati/Nat8l would affect neurogenesis and attentional behavior in mice. We found aberrant morphology of neurons and impaired neurogenesis in the dentate gyrus of Shati/Nat8l-/- mice. Additionally, research has suggested that impaired neurogenesis might be because of the reduction of dopamine in the hippocampus. Galantamine (GAL) attenuated the attentional impairment observed in the object-based attention test via increasing the dopamine release in the hippocampus of Shati/Nat8l-/- mice. The α7 nicotinic acetylcholine receptor antagonist, methyllycaconitine, and dopamine D1 receptor antagonist, SCH23390, blocked the ameliorating effect of GAL on attentional impairment in Shati/Nat8l-/- mice. These results suggest that the ameliorating effect of GAL on Shati/Nat8l-/- attentional impairment is associated with activation of D1 receptors following increased dopamine release in the hippocampus via α7 nicotinic acetylcholine receptor. In summary, Shati/Nat8l is important in both morphogenesis and neurogenesis in the dentate gyrus and attention, possible via modulation of dopaminergic transmission. Cover Image for this issue: https://doi.org/10.1111/jnc.15061.
Collapse
Affiliation(s)
- Bolati Wulaer
- Advanced Diagnostic System Research Laboratory, Fujita Health University Graduate School of Health Science, Aichi, Japan.,Department of Disease Control and Prevention, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Kazuo Kunisawa
- Department of Regulatory Science for Evaluation & Development of Pharmaceuticals & Devices, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Kazuhiro Hada
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Willy Jaya Suento
- Department of Disease Control and Prevention, Fujita Health University Graduate School of Health Science, Aichi, Japan.,Department of Psychiatry, Hasanuddin University, South Sulawesi, Indonesia
| | - Hisayoshi Kubota
- Department of Regulatory Science for Evaluation & Development of Pharmaceuticals & Devices, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Tsubasa Iida
- Department of Regulatory Science for Evaluation & Development of Pharmaceuticals & Devices, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Aika Kosuge
- Department of Regulatory Science for Evaluation & Development of Pharmaceuticals & Devices, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Taku Nagai
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Kiyofumi Yamada
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Aichi, Japan.,Japanese Drug Organization of Appropriate Use and Research, Aichi, Japan
| | - Atsumi Nitta
- Department of Pharmaceutical Therapy and Neuropharmacology, Graduate School of Pharmaceutical Sciences, University of Toyama, Toyama, Japan.,Japanese Drug Organization of Appropriate Use and Research, Aichi, Japan
| | - Yasuko Yamamoto
- Department of Disease Control and Prevention, Fujita Health University Graduate School of Health Science, Aichi, Japan
| | - Kuniaki Saito
- Advanced Diagnostic System Research Laboratory, Fujita Health University Graduate School of Health Science, Aichi, Japan.,Department of Disease Control and Prevention, Fujita Health University Graduate School of Health Science, Aichi, Japan.,Japanese Drug Organization of Appropriate Use and Research, Aichi, Japan
| | - Akihiro Mouri
- Department of Regulatory Science for Evaluation & Development of Pharmaceuticals & Devices, Fujita Health University Graduate School of Health Science, Aichi, Japan.,Japanese Drug Organization of Appropriate Use and Research, Aichi, Japan
| | - Toshitaka Nabeshima
- Advanced Diagnostic System Research Laboratory, Fujita Health University Graduate School of Health Science, Aichi, Japan.,Japanese Drug Organization of Appropriate Use and Research, Aichi, Japan
| |
Collapse
|
9
|
Stone TW. Does kynurenic acid act on nicotinic receptors? An assessment of the evidence. J Neurochem 2020; 152:627-649. [PMID: 31693759 PMCID: PMC7078985 DOI: 10.1111/jnc.14907] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 10/19/2019] [Accepted: 10/30/2019] [Indexed: 02/06/2023]
Abstract
As a major metabolite of kynurenine in the oxidative metabolism of tryptophan, kynurenic acid is of considerable biological and clinical importance as an endogenous antagonist of glutamate in the central nervous system. It is most active as an antagonist at receptors sensitive to N-methyl-D-aspartate (NMDA) which regulate neuronal excitability and plasticity, brain development and behaviour. It is also thought to play a causative role in hypo-glutamatergic conditions such as schizophrenia, and a protective role in several neurodegenerative disorders, notably Huntington's disease. An additional hypothesis, that kynurenic acid could block nicotinic receptors for acetylcholine in the central nervous system has been proposed as an alternative mechanism of action of kynurenate. However, the evidence for this alternative mechanism is highly controversial, partly because at least eight earlier studies concluded that kynurenic acid blocked NMDA receptors but not nicotinic receptors and five subsequent, independent studies designed to repeat the results have failed to do so. Many studies considered to support the alternative 'nicotinic' hypothesis have been based on the use of analogs of kynurenate such as 7-chloro-kynurenic acid, or putatively nicotinic modulators such as galantamine, but a detailed analysis of the pharmacology of these compounds suggests that the results have often been misinterpreted, especially since the pharmacology of galantamine itself has been disputed. This review examines the evidence in detail, with the conclusion that there is no confirmed, reliable evidence for an antagonist activity of kynurenic acid at nicotinic receptors. Therefore, since there is overwhelming evidence for kynurenate acting at ionotropic glutamate receptors, especially NMDAR glutamate and glycine sites, with some activity at GPR35 sites and Aryl Hydrocarbon Receptors, results with kynurenic acid should be interpreted only in terms of these confirmed sites of action.
Collapse
Affiliation(s)
- Trevor W. Stone
- Institute for Neuroscience and PsychologyUniversity of GlasgowGlasgowG12 8QQUK
- Present address:
Kennedy InstituteNDORMSUniversity of OxfordOxfordOX3 7FYUK
| |
Collapse
|
10
|
Evidence for positive allosteric modulation of cognitive-enhancing effects of nicotine in healthy human subjects. Psychopharmacology (Berl) 2020; 237:219-230. [PMID: 31686175 PMCID: PMC6952331 DOI: 10.1007/s00213-019-05363-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 09/11/2019] [Indexed: 11/16/2022]
Abstract
RATIONALE Cognitive benefits of nicotinic acetylcholine receptor (nAChR) agonists are well established but have generally been of small magnitude and uncertain clinical significance. A way of raising the effect size may be to facilitate agonist-induced responses by co-administering a nAChR positive allosteric modulator (PAM). OBJECTIVE The aim was to test whether galantamine, a PAM at several nAChR subtypes, can potentiate the cognitive-enhancing effects of nicotine. METHODS Twenty-six adult never-smokers were treated, in a double-blind counterbalanced sequence, with nicotine (7 mg/24 h, transdermally) and galantamine (4 mg, p.o.) combined, nicotine alone, galantamine alone, and double placebo. A low dose of galantamine was chosen to minimize acetylcholinesterase inhibition, which was verified in blood assays. In each condition, participants were tested with three cognitive tasks. RESULTS Nicotine significantly improved reaction time (RT) and signal detection in a visuospatial attention task and the Rapid Visual Information Processing Task. Galantamine did not modulate these effects. A trend toward RT reduction by galantamine correlated with acetylcholinesterase inhibition. In a change detection task, there were no effects of nicotine or galantamine alone on accuracy or RT. However, both drugs combined acted synergistically to reduce RT. This effect was not associated with acetylcholinesterase inhibition. CONCLUSIONS A pattern consistent with allosteric potentiation of nicotine effects by galantamine was observed on one of six performance measures. This may reflect specific nAChR subtype involvement, or additional pharmacological actions of galantamine may have overshadowed similar interactions on other measures. The finding suggests that allosteric potentiation of nAChR agonist-induced cognitive benefits is possible in principle.
Collapse
|
11
|
Saito T, Hisahara S, Iwahara N, Emoto MC, Yokokawa K, Suzuki H, Manabe T, Matsumura A, Suzuki S, Matsushita T, Kawamata J, Sato-Akaba H, Fujii HG, Shimohama S. Early administration of galantamine from preplaque phase suppresses oxidative stress and improves cognitive behavior in APPswe/PS1dE9 mouse model of Alzheimer's disease. Free Radic Biol Med 2019; 145:20-32. [PMID: 31536772 DOI: 10.1016/j.freeradbiomed.2019.09.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/12/2019] [Accepted: 09/15/2019] [Indexed: 11/26/2022]
Abstract
Alzheimer's disease (AD) is a common neurodegenerative disease that progressively impairs memory and cognition. Deposition of amyloid-β (Aβ) peptides is the most important pathophysiological hallmark of AD. Oxidative stress induced by generation of reactive oxygen species (ROS) is a prominent phenomenon in AD and known to occur early in the course of AD. Several reports suggest a relationship between change in redox status and AD pathology including progressive Aβ deposition, glial cell activation, and inflammation. Galantamine is an acetylcholinesterase inhibitor and has been reported to have an oxidative stress inhibitory function. In the present study, galantamine was administered orally to AD model mice from before the appearance of Aβ plaques (preplaque phase), and in vivo change in redox status of the brain was measured using electron paramagnetic resonance (EPR) imaging. Administration of galantamine from the preplaque phase ameliorated memory decline in Morris water maze test and novel object recognition test. Monitoring of the redox status of the brain using EPR imaging showed that galantamine treatment improved the unbalanced redox state. Additionally, galantamine administration enhanced microglial function to promote Aβ clearance, reducing the Aβ-positive area in the cortex and amount of insoluble Aβ in the brain. In contrast, galantamine treatment from the preplaque phase suppressed the production of proinflammatory cytokines through neurotoxic microglial activity. Therefore, galantamine administration from the preplaque phase may have the potential of clinical application for the prevention of AD. In addition, our results demonstrate the usefulness of EPR imaging for speedy and quantitative evaluation of the efficacy of disease-modifying drugs for AD.
Collapse
Affiliation(s)
- Taro Saito
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Shin Hisahara
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Naotoshi Iwahara
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan; Department of Pharmacology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Miho C Emoto
- Department of Clinical Laboratory Science, School of Medical Technology, Health Sciences University of Hokkaido, Sapporo, Hokkaido, 002-8072, Japan
| | - Kazuki Yokokawa
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Hiromi Suzuki
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Tatsuo Manabe
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Akihiro Matsumura
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Syuuichirou Suzuki
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Takashi Matsushita
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Jun Kawamata
- Department of Neurology, Kitasato University School of Medicine, Sagamihara, Kanagawa, 252-0374, Japan
| | - Hideo Sato-Akaba
- Department of Systems Innovation, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, 560-8531, Japan
| | - Hirotada G Fujii
- Cancer Preventive Institute, Health Sciences University of Hokkaido, Ishikari, Hokkaido, 061-0293, Japan
| | - Shun Shimohama
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan.
| |
Collapse
|
12
|
Aponte EA, Schöbi D, Stephan KE, Heinzle J. Computational Dissociation of Dopaminergic and Cholinergic Effects on Action Selection and Inhibitory Control. BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2019; 5:364-372. [PMID: 31952937 DOI: 10.1016/j.bpsc.2019.10.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 10/06/2019] [Accepted: 10/28/2019] [Indexed: 12/23/2022]
Abstract
BACKGROUND Patients with schizophrenia make more errors than healthy subjects in the antisaccade task. In this paradigm, participants are required to inhibit a reflexive saccade to a target and to select the correct action (a saccade in the opposite direction). While the precise origin of this deficit is not clear, it has been connected to aberrant dopaminergic and cholinergic neuromodulation. METHODS To study the impact of dopamine and acetylcholine on inhibitory control and action selection, we administered two selective drugs (levodopa 200 mg/galantamine 8 mg) to healthy volunteers (N = 100) performing the antisaccade task. The computational model SERIA (stochastic early reaction, inhibition, and late action) was employed to separate the contribution of inhibitory control and action selection to empirical reaction times and error rates. RESULTS Modeling suggested that levodopa improved action selection (at the cost of increased reaction times) but did not have a significant effect on inhibitory control. By contrast, according to our model, galantamine affected inhibitory control in a dose-dependent fashion, reducing inhibition failures at low doses and increasing them at higher levels. These effects were sufficiently specific that the computational analysis allowed for identifying the drug administered to an individual with 70% accuracy. CONCLUSIONS Our results do not support the hypothesis that elevated tonic dopamine strongly impairs inhibitory control. Rather, levodopa improved the ability to select correct actions. However, inhibitory control was modulated by cholinergic drugs. This approach may provide a starting point for future computational assays that differentiate neuromodulatory abnormalities in heterogeneous diseases like schizophrenia.
Collapse
Affiliation(s)
- Eduardo A Aponte
- Translational Neuromodeling Unit, Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.
| | - Dario Schöbi
- Translational Neuromodeling Unit, Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Klaas E Stephan
- Translational Neuromodeling Unit, Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland; Wellcome Centre for Human Neuroimaging, University College London, London, United Kingdom; Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Jakob Heinzle
- Translational Neuromodeling Unit, Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.
| |
Collapse
|
13
|
Singhal M, Merino V, Rosini M, Cavalli A, Kalia YN. Controlled Iontophoretic Delivery in Vitro and in Vivo of ARN14140-A Multitarget Compound for Alzheimer's Disease. Mol Pharm 2019; 16:3460-3468. [PMID: 31241959 DOI: 10.1021/acs.molpharmaceut.9b00252] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
ARN14140 is a galantamine-memantine conjugate that acts upon both cholinergic and glutamatergic pathways for better management of Alzheimer's disease. Poor oral bioavailability and pharmacokinetics meant that earlier preclinical in vivo studies employed intracerebroventricular injection to administer ARN14140 directly to the brain. The aim of the present study was to evaluate the feasibility of using constant current transdermal iontophoresis for the noninvasive systemic delivery of ARN14140 and to quantify the amounts present in the blood and the brain. Preliminary experiments in vitro were performed using porcine skin and validated with human skin. Cumulative ARN14140 permeation across the skin increased linearly with current density and concentration. Delivery efficiency (i.e., fraction of the amount applied that is delivered) reached an exceptional 76.9%. Statistically equivalent delivery was observed after iontophoresis across human and porcine skin. In vivo studies in male Wistar rats showed that iontophoretic transport of ARN14140 could be controlled using the current density (426.7 ± 42 and 1118.3 ± 73 nmol/cm2 at 0.15 and 0.5 mA/cm2 for 6 h) and demonstrated that transdermal iontophoresis was able to deliver ARN14140 noninvasively to the brain. This is the first report quantifying drug levels in the blood and the brain following transdermal iontophoresis.
Collapse
Affiliation(s)
- Mayank Singhal
- School of Pharmaceutical Sciences , University of Geneva and University of Lausanne , Geneva , Switzerland
| | - Virginia Merino
- Instituto Interuniversitario de Investigación de Reconocimiento Molecular y Desarrollo Tecnológico (IDM) Universitat Politecnica de València , Universitat de València , Valencia , Spain.,Departamento de Farmacia y Tecnología Farmacéutica y Parasitología, Facultad de Farmacia , Universitat de València , Valencia , Spain
| | - Michela Rosini
- Department of Pharmacy and Biotechnology , University of Bologna , Bologna , Italy
| | - Andrea Cavalli
- Department of Pharmacy and Biotechnology , University of Bologna , Bologna , Italy.,Drug Discovery and Development , Istituto Italiano di Tecnologia , Genova , Italy
| | - Yogeshvar N Kalia
- School of Pharmaceutical Sciences , University of Geneva and University of Lausanne , Geneva , Switzerland
| |
Collapse
|
14
|
Koola MM. Potential Role of Antipsychotic-Galantamine-Memantine Combination in the Treatment of Positive, Cognitive, and Negative Symptoms of Schizophrenia. MOLECULAR NEUROPSYCHIATRY 2018; 4:134-148. [PMID: 30643787 PMCID: PMC6323397 DOI: 10.1159/000494495] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 10/12/2018] [Indexed: 12/11/2022]
Abstract
Schizophrenia is, in part, a cognitive illness. There are no approved medications for cognitive impairments associated with schizophrenia (CIAS) and primary negative symptoms. Cholinergic and glutamatergic systems, alpha-7 nicotinic acetylcholine (α-7nACh) and N-methyl-D-aspartate (NMDA) receptors, kynurenic acid (KYNA), and mismatch negativity have been implicated in the pathophysiology of CIAS and negative symptoms. Galantamine is an acetylcholinesterase inhibitor that is also a positive allosteric modulator at the α4β2 and α7nACh receptors. Memantine is a noncompetitive NMDA receptor antagonist. Galantamine and memantine alone and in combination were effective for cognition in animals and people with Alzheimer's disease. The objective of this article is to critically dissect the published randomized controlled trials with galantamine and memantine for CIAS to highlight the efficacy signal. These studies may have failed to detect a clinically meaningful efficacy signal due to limitations, methodological issues, and possible medication nonadherence. There is evidence from a small open-label study that the galantamine-memantine combination may be effective for CIAS with kynurenine pathway metabolites as biomarkers to detect the severity of cognitive impairments. Given that there are no available treatments for cognitive impairments and primary negative symptoms in schizophrenia, testing of this "five-pronged strategy" (quintuple hypotheses: dopamine, nicotinic-cholinergic, glutamatergic/NMDA, GABA, and KYNA) is a "low-risk high-gain" approach that could be a major breakthrough in the field. The galantamine-memantine combination has the potential to treat positive, cognitive, and negative symptoms, and targeting the quintuple hypotheses concurrently may lead to a major scientific advancement - from antipsychotic treatment to antischizophrenia treatment.
Collapse
Affiliation(s)
- Maju Mathew Koola
- Department of Psychiatry and Behavioral Sciences, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA
| |
Collapse
|
15
|
Matsuda T, Hisatsune T. Cholinergic Modification of Neurogenesis and Gliosis Improves the Memory of AβPPswe/PSEN1dE9 Alzheimer's Disease Model Mice Fed a High-Fat Diet. J Alzheimers Dis 2018; 56:1-23. [PMID: 27911310 DOI: 10.3233/jad-160761] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We previously reported that neuroinflammation contributes to the amnesia of AβPPswe/PSEN1dE9 Alzheimer's disease model mice fed a high-fat diet to induce type-2 diabetes (T2DM-AD mice), but the underlying mechanism for the memory decline remained unclear. Recent studies have suggested that cholinergic modulation is involved in neuroinflammatory cellular reactions including neurogenesis and gliosis, and in memory improvement. In this study, we administered a broad-spectrum cholinesterase inhibitor, rivastigmine (2 mg/kg/day, s.c.), into T2DM-AD mice for 6 weeks, and evaluated their memory performance, neurogenesis, and neuroinflammatory reactions. By two hippocampal-dependent memory tests, the Morris water maze and contextual fear conditioning, rivastigmine improved the memory deterioration of the T2DM-AD mice (n = 8, p < 0.01). The number of newborn neurons in the hippocampal dentate gyrus was 1138±324 (Ave±SEM) in wild-type littermates, 2573±442 in T2DM-AD-Vehicle, and 2165±300 in T2DM-AD-Rivastigmine mice, indicating that neurogenesis was accelerated in the two T2DM-AD groups (n = 5, p < 0.05). The dendritic maturation of new neurons in T2DM-AD-Vehicle mice was severely abrogated, and rivastigmine treatment reversed this retarded maturation. In addition, the hippocampus of T2DM-AD-Vehicle mice showed increased proinflammatory cytokines IL-1β and TNF-α and gliosis, and rivastigmine treatment blocked these inflammatory reactions. Rivastigmine did not change the insulin abnormality or amyloid pathology in these mice. Thus, cholinergic modulation by rivastigmine treatment led to enhanced neurogenesis and the suppression of gliosis, which together ameliorated the memory decline in T2DM-AD model mice.
Collapse
|
16
|
Golime R, Palit M, Acharya J, Dubey DK. Neuroprotective Effects of Galantamine on Nerve Agent-Induced Neuroglial and Biochemical Changes. Neurotox Res 2017; 33:738-748. [DOI: 10.1007/s12640-017-9815-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 09/04/2017] [Accepted: 09/05/2017] [Indexed: 10/18/2022]
|
17
|
Khanam H, Ali A, Asif M, Shamsuzzaman. Neurodegenerative diseases linked to misfolded proteins and their therapeutic approaches: A review. Eur J Med Chem 2016; 124:1121-1141. [DOI: 10.1016/j.ejmech.2016.08.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 08/02/2016] [Accepted: 08/05/2016] [Indexed: 12/11/2022]
|
18
|
Abstract
Scenic view at high altitude is a pleasure to the eyes, but it has some shortcoming effects as well. High altitude can be divided into different categories, i.e., high altitude (3000-5000 ft), very high altitude (5000-8000 ft), and extreme altitude (above 8000 ft). Much of the population resides at high altitude, and others go there for tourism. Military personnel are also posted there to defend boundaries. As we ascent to high altitude, partial pressure of oxygen reduces, whereas concentration remains the same; this reduces the availability of oxygen to different body parts. This pathophysiological condition is known as hypobaric hypoxia (HH) which leads to oxidative stress and further causes cognitive dysfunction in some cases. Hypoxia causes neurodegeneration in different brain regions; however, the hippocampus is found to be more prone in comparison to other brain regions. As the hippocampus is affected most, therefore, spatial memory is impaired most during such condition. This chapter will give a brief review of the damaging effect of high altitude on cognition and also throw light on possible herbal interventions at high altitude, which can improve cognitive performance as well as provide protection against the deteriorating effect of hypobaric hypoxia at high altitude.
Collapse
Affiliation(s)
- Vishal Jain
- Vallabhbhai Patel Chest Institute, Delhi University, Delhi, 110007, India.
| |
Collapse
|
19
|
Jiang Y, Liu Z, Holenz J, Yang H. Competitive Intelligence–based Lead Generation and Fast Follower Approaches. ACTA ACUST UNITED AC 2016. [DOI: 10.1002/9783527677047.ch08] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
20
|
Takeda K, Yamaguchi Y, Hino M, Kato F. Potentiation of Acetylcholine-Mediated Facilitation of Inhibitory Synaptic Transmission by an Azaindolizione Derivative, ZSET1446 (ST101), in the Rat Hippocampus. ACTA ACUST UNITED AC 2015; 356:445-55. [DOI: 10.1124/jpet.115.229021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 11/16/2015] [Indexed: 11/22/2022]
|
21
|
Koola MM, Buchanan RW, Pillai A, Aitchison KJ, Weinberger DR, Aaronson ST, Dickerson FB. Potential role of the combination of galantamine and memantine to improve cognition in schizophrenia. Schizophr Res 2014; 157:84-9. [PMID: 24878431 PMCID: PMC4099270 DOI: 10.1016/j.schres.2014.04.037] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 04/22/2014] [Accepted: 04/26/2014] [Indexed: 12/28/2022]
Abstract
The Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) and Treatment Units for Research on Neurocognition and Schizophrenia projects were designed to facilitate the development of new drugs for the treatment of cognitive impairments in people with schizophrenia. The MATRICS project identified three drug mechanisms of particular interest: dopaminergic, cholinergic, and glutamatergic. As a group, while people with schizophrenia have moderate cognitive impairment, it is the best predictor of long-term outcome. Unfortunately, there are no approved medications for cognitive impairment in this population. Hence, the development of new pharmacological approaches is critical for reducing illness-related disability. The combination of an acetylcholinesterase inhibitor (AChEI) and memantine is more effective than either medication alone to improve cognition in Alzheimer's dementia. Galantamine is not only an AChEI, but also a positive allosteric modulator of the α4β2 and α7 nicotinic receptors. Hypofunction of N-methyl-d-aspartate (NMDA) receptors has been implicated in the pathophysiology of cognitive symptoms in schizophrenia and hence memantine may positively impact cognition. Memantine decreases the tonic NMDA current and galantamine enhances the action potential mediated by a postsynaptic NMDA current. This results in an increased signal transmission; therefore, a greater signal-to-noise ratio occurs with the combination than memantine alone. Galantamine improves the α-amino-3-hydroxy-5-methyl-4-isoxazol-propionate (AMPA)-mediated signaling which could be neuroprotective and may improve memory coding. The combination of galantamine and memantine may be particularly effective in schizophrenia in order to increase the selective cognition enhancement produced by either medication alone. In the future, multitarget-directed ligands may play a role in the treatment of complex diseases like schizophrenia.
Collapse
Affiliation(s)
- Maju Mathew Koola
- Sheppard Pratt Health System, Baltimore, MD, USA; Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Robert W. Buchanan
- Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Anilkumar Pillai
- Department of Psychiatry and Health Behavior, Georgia Regents University, Augusta, GA, USA
| | - Katherine J. Aitchison
- Department of Psychiatry and Medical Genetics, University of Alberta, Edmonton, Alberta, Canada
| | - Daniel R. Weinberger
- Lieber Institute for Brain Development, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Scott T. Aaronson
- Sheppard Pratt Health System, Baltimore, MD, USA,Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Faith B. Dickerson
- Sheppard Pratt Health System, Baltimore, MD, USA,Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| |
Collapse
|
22
|
Ghaleiha A, Ghyasvand M, Mohammadi MR, Farokhnia M, Yadegari N, Tabrizi M, Hajiaghaee R, Yekehtaz H, Akhondzadeh S. Galantamine efficacy and tolerability as an augmentative therapy in autistic children: A randomized, double-blind, placebo-controlled trial. J Psychopharmacol 2014; 28:677-85. [PMID: 24132248 DOI: 10.1177/0269881113508830] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The role of cholinergic abnormalities in autism was recently evidenced and there is a growing interest in cholinergic modulation, emerging for targeting autistic symptoms. Galantamine is an acetylcholinesterase inhibitor and an allosteric potentiator of nicotinic receptors. This study aimed to evaluate the possible effects of galantamine as an augmentative therapy to risperidone, in autistic children. In this randomized, double-blind, placebo-controlled, parallel-group study, 40 outpatients aged 4-12 years whom had a diagnosis of autism (DSM IV-TR) and a score of 12 or higher on the Aberrant Behavior Checklist-Community (ABC-C) Irritability subscale were equally randomized to receive either galantamine (up to 24 mg/day) or placebo, in addition to risperidone (up to 2 mg/day), for 10 weeks. We rated participants by ABC-C and a side effects checklist, at baseline and at weeks 5 and 10. By the study endpoint, the galantamine-treated patients showed significantly greater improvement in the Irritability (P = 0.017) and Lethargy/Social Withdrawal (P = 0.005) subscales than the placebo group. The difference between the two groups in the frequency of side effects was not significant. In conclusion, galantamine augmentation was shown to be a relatively effective and safe augmentative strategy for alleviating some of the autism-related symptoms.
Collapse
Affiliation(s)
- Ali Ghaleiha
- Research Center for Behavioral Disorders and Substance Abuse, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mohammad Ghyasvand
- Psychiatric Research Center, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad-Reza Mohammadi
- Psychiatric Research Center, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Farokhnia
- Psychiatric Research Center, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Noorollah Yadegari
- Psychiatric Research Center, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mina Tabrizi
- Department of Medical Genetics, Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Hajiaghaee
- Medicinal Plants Research Center, Institute of Medicinal Plants, Karaj, Iran
| | - Habibeh Yekehtaz
- Psychiatric Research Center, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Shahin Akhondzadeh
- Psychiatric Research Center, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran, Iran
| |
Collapse
|
23
|
Andriambeloson E, Huyard B, Poiraud E, Wagner S. Methyllycaconitine- and scopolamine-induced cognitive dysfunction: differential reversal effect by cognition-enhancing drugs. Pharmacol Res Perspect 2014; 2:e00048. [PMID: 25505596 PMCID: PMC4186438 DOI: 10.1002/prp2.48] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 03/26/2014] [Indexed: 12/14/2022] Open
Abstract
There is a growing body of evidence pointing to the pivotal role of alpha-7 nicotinic acetylcholine receptor (α7 nAchR) dysfunction in cognitive disorders such as Alzheimer’s disease or schizophrenia. This study was undertaken to establish and characterize an in vivo model for cognitive disorder secondary to the blockade of α7 nAChR by its specific antagonist, methyllycaconitine (MLA). The results show that MLA elicited cognitive dysfunction as assessed by reduced spontaneous alternation of mice in the T-maze. The maximal effect of MLA produced 25–30% reduction in the spontaneous alternation of mice, a level comparable with that induced by the muscarinic antagonism of scopolamine. Donepezil and galantamine fully reversed both MLA and scopolamine-induced cognitive dysfunction. However, the ED50 of donepezil and galantamine was significantly shifted to the left in the MLA- compared to scopolamine-treated mice (0.0005 and 0.002 mg/kg for donepezil; 0.0003 and 0.7 mg/kg for galantamine). Moreover, memantine elicited marked reversion of cognitive dysfunction (up to 70%) in MLA-treated mice while only a weak reversal effect at high dose of memantine (less than 20%) was observed in scopolamine-treated mice. The above findings indicate that MLA-induced cognitive dysfunction in the mouse is highly sensitive and more responsive to the current procognitive drugs than the traditional scopolamine-based assay. Thus, it can be of value for the preclinical screening and profiling of cognition-enhancing drugs.
Collapse
Affiliation(s)
- Emile Andriambeloson
- Neurofit SAS boulevard Sébastien Brant, Bioparc Parc d'Innovation, 674.00, Illkirch, France
| | - Bertrand Huyard
- Neurofit SAS boulevard Sébastien Brant, Bioparc Parc d'Innovation, 674.00, Illkirch, France
| | - Etienne Poiraud
- Neurofit SAS boulevard Sébastien Brant, Bioparc Parc d'Innovation, 674.00, Illkirch, France
| | - Stéphanie Wagner
- Neurofit SAS boulevard Sébastien Brant, Bioparc Parc d'Innovation, 674.00, Illkirch, France
| |
Collapse
|
24
|
Sasaki S, Horie Y. The Effects of an Uninterrupted Switch from Donepezil to Galantamine without Dose Titration on Behavioral and Psychological Symptoms of Dementia in Alzheimer's Disease. Dement Geriatr Cogn Dis Extra 2014; 4:131-9. [PMID: 24987402 PMCID: PMC4067716 DOI: 10.1159/000362871] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Aims To elucidate the efficacy of galantamine on cognition and behavioral and psychological symptoms of dementia (BPSD) in outpatients with mild cognitive impairment (MCI) and Alzheimer's disease (AD) who have switched from donepezil to galantamine. Materials and Methods We performed an uninterrupted switch from donepezil to galantamine without a washout period or dose titration in 44 ambulatory outpatients with amnestic MCI (n = 12) or mild-to-moderate AD (n = 32). Three months after the switch, the efficacy of galantamine was evaluated with the Mini-Mental State Examination (MMSE), and the Neuropsychiatric Inventory (NPI) and NPI Brief Questionnaire Form (NPI-Q), respectively, using the Wilcoxon signed-rank test. Results NPI scores improved significantly on BPSD, especially on delusions, agitation and aberrant motor activity in AD patients (p = 0.027); improvement was remarkable in patients with moderate AD (MMSE score 10-19; p = 0.007), while insignificant in those with MCI (MMSE score ≥24; p = 0.648). The NPI-Q score also improved significantly regarding both the severity of the disease (p = 0.009) and caregiver distress (p = 0.012) in AD patients. MMSE scores hardly improved in either MCI (p = 0.394) or AD patients (p = 0.265). Conclusions An uninterrupted switch from donepezil to galantamine could be a useful alternative treatment option for AD patients whose BPSD are unresponsive to donepezil, or whose caregivers are not satisfied with donepezil treatment. © 2014 S. Karger AG, Basel
Collapse
Affiliation(s)
- Shoichi Sasaki
- Department of Neurology, Tokyo Women's Medical University, Tokyo, Japan
| | - Yoshiharu Horie
- Division of Biostatistics, Kitasato University Graduate School, Sagamihara, Japan
| |
Collapse
|
25
|
Su YA, Huang RH, Wang XD, Li JT, Si TM. Impaired working memory by repeated neonatal MK-801 treatment is ameliorated by galantamine in adult rats. Eur J Pharmacol 2014; 725:32-9. [PMID: 24440172 DOI: 10.1016/j.ejphar.2014.01.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 12/23/2013] [Accepted: 01/08/2014] [Indexed: 01/27/2023]
Abstract
Early life blockade of the NMDA receptor by using MK-801, a non-competitive NMDA receptor antagonist, induces behavioral changes that mimic several features of schizophrenia. In the current study, we first examined the effects of neonatal MK-801 treatment in male Sprague-Dawley rats on locomotor activity, prepulse inhibition and spatial working memory in adolescence (postnatal day 35, PND35) and adulthood (PND63). Next, we investigated the effects of an acetylcholinesterase inhibitor, galantamine, on working memory deficits induced by MK-801 treatment. Rats were treated with either saline or MK-801 (0.25mg/kg twice daily) at PND 5-14, and the long-term behavioral effects were investigated. MK-801 treated rats showed moderate working memory impairments in adolescence but a pronounced deficit in adulthood. However, locomotion and prepulse inhibition at two life stages were not affected by this treatment. Systemic administration of galantamine (1mg/kg) 30 min before each training session significantly improved neonatal MK-801-induced working memory deficits in adulthood. In conclusion, these results suggest that the neonatal MK-801 treatment-induced selective working memory deficit is related to a change in brain cholinergic systems.
Collapse
Affiliation(s)
- Yun-Ai Su
- Key Laboratory of Mental Health, Ministry of Health (Peking University), Beijing, PR China; Institute of Mental Health, Peking University, Beijing, PR China
| | - Run-Hu Huang
- Key Laboratory of Mental Health, Ministry of Health (Peking University), Beijing, PR China; Institute of Mental Health, Peking University, Beijing, PR China; Shanxi Dayi Hospital, Taiyuan, Shanxi Province, PR China
| | - Xiao-Dong Wang
- Key Laboratory of Mental Health, Ministry of Health (Peking University), Beijing, PR China; Institute of Mental Health, Peking University, Beijing, PR China
| | - Ji-Tao Li
- Key Laboratory of Mental Health, Ministry of Health (Peking University), Beijing, PR China; Institute of Mental Health, Peking University, Beijing, PR China
| | - Tian-Mei Si
- Key Laboratory of Mental Health, Ministry of Health (Peking University), Beijing, PR China; Institute of Mental Health, Peking University, Beijing, PR China.
| |
Collapse
|
26
|
Acetylcholinesterase inhibitors as Alzheimer therapy: From nerve toxins to neuroprotection. Eur J Med Chem 2013; 70:165-88. [DOI: 10.1016/j.ejmech.2013.09.050] [Citation(s) in RCA: 223] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 09/24/2013] [Accepted: 09/28/2013] [Indexed: 11/22/2022]
|
27
|
Liu X. Positive allosteric modulation of α4β2 nicotinic acetylcholine receptors as a new approach to smoking reduction: evidence from a rat model of nicotine self-administration. Psychopharmacology (Berl) 2013; 230:203-13. [PMID: 23712602 PMCID: PMC3797181 DOI: 10.1007/s00213-013-3145-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 05/06/2013] [Indexed: 12/14/2022]
Abstract
RATIONALE The α4β2 subtype of nicotinic acetylcholine receptors (nAChRs) plays a central role in the mediation of nicotine reinforcement. Positive allosteric modulators (PAMs) at α4β2 nAChRs facilitate the intrinsic efficiency of these receptors, although they do not directly activate the receptors. α4β2 PAMs are hypothesized to reduce nicotine self-administration in subjects engaged in routine nicotine consumption. The present study tested this hypothesis using a rat model of nicotine self-administration. METHODS Male Sprague-Dawley rats were trained in daily 1-h sessions to intravenously self-administer nicotine (0.03 mg/kg per infusion, free base) on a fixed-ratio 5 schedule. The effects of the α4β2 PAM desformylflustrabromine (dFBr), α4β2 agonist 5-iodo-A-85380, and acetylcholinesterase inhibitor galantamine on nicotine intake were examined. The ability of dFBr and 5-iodo-A-85380 to substitute for nicotine was also assessed. RESULTS dFBr and 5-iodo-A-85380 dose-dependently reduced nicotine self-administration without changing lever responses for food. Galantamine decreased the self-administration of nicotine and food at high doses. Unlike 5-iodo-A-85380, dFBr failed to substitute for nicotine in supporting self-administration behavior. CONCLUSIONS These results demonstrated the effectiveness of dFBr in reducing nicotine intake and the inability of dFBr to support self-administration behavior. These findings suggest that positive allosteric modulation of α4β2 nAChRs may be a promising target for the treatment of nicotine addiction. Moreover, α4β2 PAMs, in contrast to agonist medications, may have clinical advantages because they may have little liability for abuse because of their lack of reinforcing actions on their own.
Collapse
Affiliation(s)
- Xiu Liu
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA,
| |
Collapse
|
28
|
Synthesis of bistetrahydroquinolines as potential anticholinesterasic agents by double Diels-Alder reactions. Molecules 2013; 18:12951-65. [PMID: 24141245 PMCID: PMC6270290 DOI: 10.3390/molecules181012951] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 09/27/2013] [Accepted: 10/08/2013] [Indexed: 12/02/2022] Open
Abstract
The tetrahydroquinoline ring system is a unit found in many biologically active natural products and pharmacologically relevant therapeutic agents. A new series of bistetrahydroquinolines (bis-THQs) was synthesized using imino Diels-Alder reactions between dialdehydes, anilines and N-vinyl-2-pyrrolidone (NVP). The notable features of this procedure are mild reaction conditions, greater selectivity and good yields of products. In addition, the inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) of some selected derivatives is reported. The feasible binding modes of these active compounds, within AChE and BuChE binding sites, were predicted by molecular docking experiments and their binding affinity was estimated by means of free energy calculations through the MM-GBSA approximation.
Collapse
|
29
|
Two receptors are involved in the central functions of kynurenic acid under an acute stress in neonatal chicks. Neuroscience 2013; 248:194-200. [DOI: 10.1016/j.neuroscience.2013.06.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 05/30/2013] [Accepted: 06/04/2013] [Indexed: 11/22/2022]
|
30
|
Towards a molecular understanding of the biosynthesis of amaryllidaceae alkaloids in support of their expanding medical use. Int J Mol Sci 2013; 14:11713-41. [PMID: 23727937 PMCID: PMC3709753 DOI: 10.3390/ijms140611713] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 05/26/2013] [Accepted: 05/27/2013] [Indexed: 12/28/2022] Open
Abstract
The alkaloids characteristically produced by the subfamily Amaryllidoideae of the Amaryllidaceae, bulbous plant species that include well know genera such as Narcissus (daffodils) and Galanthus (snowdrops), are a source of new pharmaceutical compounds. Presently, only the Amaryllidaceae alkaloid galanthamine, an acetylcholinesterase inhibitor used to treat symptoms of Alzheimer's disease, is produced commercially as a drug from cultivated plants. However, several Amaryllidaceae alkaloids have shown great promise as anti-cancer drugs, but their further clinical development is restricted by their limited commercial availability. Amaryllidaceae species have a long history of cultivation and breeding as ornamental bulbs, and phytochemical research has focussed on the diversity in alkaloid content and composition. In contrast to the available pharmacological and phytochemical data, ecological, physiological and molecular aspects of the Amaryllidaceae and their alkaloids are much less explored and the identity of the alkaloid biosynthetic genes is presently unknown. An improved molecular understanding of Amaryllidaceae alkaloid biosynthesis would greatly benefit the rational design of breeding programs to produce cultivars optimised for the production of pharmaceutical compounds and enable biotechnology based approaches.
Collapse
|
31
|
Beggiato S, Antonelli T, Tomasini MC, Tanganelli S, Fuxe K, Schwarcz R, Ferraro L. Kynurenic acid, by targeting α7 nicotinic acetylcholine receptors, modulates extracellular GABA levels in the rat striatum in vivo. Eur J Neurosci 2013; 37:1470-7. [PMID: 23442092 DOI: 10.1111/ejn.12160] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 01/14/2013] [Accepted: 01/17/2013] [Indexed: 01/02/2023]
Abstract
Kynurenic acid (KYNA) is an astrocyte-derived non-competitive antagonist of the α7 nicotinic acetylcholine receptor (α7nAChR) and inhibits the NMDA receptor (NMDAR) competitively. The main aim of the present study was to examine the possible effects of KYNA (30 - 1000 nm), applied locally by reverse dialysis for 2 h, on extracellular GABA levels in the rat striatum. KYNA concentration-dependently reduced GABA levels, with 300 nm KYNA causing a maximal reduction to ~60% of baseline concentrations. The effect of KYNA (100 nm) was prevented by co-application of galantamine (5 μm), an agonist at a site of the α7nAChR that is very similar to that targeted by KYNA. Infusion of 7-chlorokynurenic acid (100 nm), an NMDAR antagonist acting selectively at the glycineB site of the receptor, affected neither basal GABA levels nor the KYNA-induced reduction in GABA. Inhibition of endogenous KYNA formation by reverse dialysis of (S)-4-(ethylsulfonyl)benzoylalanine (ESBA; 1 mm) increased extracellular GABA levels, reaching a peak of 156% of baseline levels after 1 h. Co-infusion of 100 nm KYNA abolished the effect of ESBA. Qualitatively and quantitatively similar, bi-directional effects of KYNA on extracellular glutamate were observed in the same microdialysis samples. Taken together, the present findings suggest that fluctuations in endogenous KYNA levels, by modulating α7nAChR function, control extracellular GABA levels in the rat striatum. This effect may be relevant for a number of physiological and pathological processes involving the basal ganglia.
Collapse
Affiliation(s)
- Sarah Beggiato
- Department of Medical Sciences, University of Ferrara, Via Fossato di Mortara 17-19, 44100 Ferrara, Italy.
| | | | | | | | | | | | | |
Collapse
|
32
|
Galantamine increases hippocampal insulin-like growth factor 2 expression via α7 nicotinic acetylcholine receptors in mice. Psychopharmacology (Berl) 2013; 225:543-51. [PMID: 22932776 DOI: 10.1007/s00213-012-2841-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 07/31/2012] [Indexed: 01/17/2023]
Abstract
RATIONALE AND OBJECTIVE Galantamine, a drug for the treatment of Alzheimer's disease, has neuroprotection in several experimental models and stimulates adult neurogenesis in the rodent brain, but the exact mechanism remains unclear. This study examined whether galantamine affects the expression of neurotrophic/growth factors in the mouse hippocampus and prefrontal cortex. METHODS Nine-week-old male ddY mice were used. The mRNA levels of neurotrophic/growth factors were analyzed by a real-time quantitative PCR. The protein levels of insulin-like growth factor 2 (IGF2) were analyzed by Western blotting. RESULTS Acute administration of galantamine (0.3-3 mg/kg, i.p.) increased IGF2 mRNA levels in the hippocampus, but not in the prefrontal cortex, in time- and dose-dependent manner. Galantamine (3 mg/kg, i.p.) caused a transient increase in fibroblast growth factor 2 mRNA levels and a decrease in brain-derived neurotrophic factor mRNA levels in the hippocampus, while it did not affect the mRNA levels of other neurotrophic/growth factors. The galantamine-induced increase in the hippocampal IGF2 mRNA levels was blocked by mecamylamine, a nonselective nicotinic acetylcholine (ACh) receptor (nAChR) antagonist, and methyllycaconitine, a selective α7 nAChR antagonist, but not by telenzepine, a preferential M(1) muscarinic ACh receptor antagonist. Moreover, the selective α7 nAChR agonist PHA-543613 increased the IGF2 mRNA levels, while donepezil, an acetylcholinesterase inhibitor, did not. Galantamine also increased hippocampal IGF2 protein, which was blocked by methyllycaconitine. CONCLUSIONS These findings suggest that galantamine increases hippocampal IGF2 levels via α7 nAChR activation in mice and imply that the effect may contribute to its neuroprotection or neurogenesis.
Collapse
|
33
|
Simoni E, Daniele S, Bottegoni G, Pizzirani D, Trincavelli ML, Goldoni L, Tarozzo G, Reggiani A, Martini C, Piomelli D, Melchiorre C, Rosini M, Cavalli A. Combining Galantamine and Memantine in Multitargeted, New Chemical Entities Potentially Useful in Alzheimer’s Disease. J Med Chem 2012; 55:9708-21. [DOI: 10.1021/jm3009458] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Elena Simoni
- Drug Discovery and Development, Istituto Italiano di Tecnologia, via Morego 30, 16163
Genova, Italy
- Department
of Pharmaceutical
Sciences, Alma Mater Studiorum − Bologna University, via Belmeloro 6, 40126 Bologna, Italy
| | - Simona Daniele
- Drug Discovery and Development, Istituto Italiano di Tecnologia, via Morego 30, 16163
Genova, Italy
- Department of Psychiatry, Neurobiology,
Pharmacology and Biotechnology, University of Pisa, via Bonanno 6, 56126 Pisa, Italy
| | - Giovanni Bottegoni
- Drug Discovery and Development, Istituto Italiano di Tecnologia, via Morego 30, 16163
Genova, Italy
| | - Daniela Pizzirani
- Drug Discovery and Development, Istituto Italiano di Tecnologia, via Morego 30, 16163
Genova, Italy
| | - Maria L. Trincavelli
- Department of Psychiatry, Neurobiology,
Pharmacology and Biotechnology, University of Pisa, via Bonanno 6, 56126 Pisa, Italy
| | - Luca Goldoni
- Drug Discovery and Development, Istituto Italiano di Tecnologia, via Morego 30, 16163
Genova, Italy
| | - Glauco Tarozzo
- Drug Discovery and Development, Istituto Italiano di Tecnologia, via Morego 30, 16163
Genova, Italy
| | - Angelo Reggiani
- Drug Discovery and Development, Istituto Italiano di Tecnologia, via Morego 30, 16163
Genova, Italy
| | - Claudia Martini
- Department of Psychiatry, Neurobiology,
Pharmacology and Biotechnology, University of Pisa, via Bonanno 6, 56126 Pisa, Italy
| | - Daniele Piomelli
- Drug Discovery and Development, Istituto Italiano di Tecnologia, via Morego 30, 16163
Genova, Italy
- Departments of Pharmacology
and Biological Chemistry, University of California, Irvine 92697-4621, United States
| | - Carlo Melchiorre
- Department
of Pharmaceutical
Sciences, Alma Mater Studiorum − Bologna University, via Belmeloro 6, 40126 Bologna, Italy
| | - Michela Rosini
- Department
of Pharmaceutical
Sciences, Alma Mater Studiorum − Bologna University, via Belmeloro 6, 40126 Bologna, Italy
| | - Andrea Cavalli
- Drug Discovery and Development, Istituto Italiano di Tecnologia, via Morego 30, 16163
Genova, Italy
- Department
of Pharmaceutical
Sciences, Alma Mater Studiorum − Bologna University, via Belmeloro 6, 40126 Bologna, Italy
| |
Collapse
|
34
|
Pohanka M. Alpha7 nicotinic acetylcholine receptor is a target in pharmacology and toxicology. Int J Mol Sci 2012; 13:2219-2238. [PMID: 22408449 PMCID: PMC3292018 DOI: 10.3390/ijms13022219] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 01/26/2012] [Accepted: 02/14/2012] [Indexed: 01/18/2023] Open
Abstract
Alpha7 nicotinic acetylcholine receptor (α7 nAChR) is an important part of the cholinergic nerve system in the brain. Moreover, it is associated with a cholinergic anti-inflammatory pathway in the termination of the parasympathetic nervous system. Antagonists of α7 nAChR are a wide group represented by conotoxin and bungarotoxin. Even Alzheimer's disease drug memantine acting as an antagonist in its side pathway belongs in this group. Agonists of α7 nAChR are suitable for treatment of multiple cognitive dysfunctions such as Alzheimer's disease or schizophrenia. Inflammation or even sepsis can be ameliorated by the agonistic acting compounds. Preparations RG3487, SEN34625/WYE-103914, SEN12333, ABT-107, Clozapine, GTS-21, CNI-1493, and AR-R17779 are representative examples of the novel compounds with affinity toward the α7 nAChR. Pharmacological, toxicological, and medicinal significance of α7 nAChR are discussed throughout this paper.
Collapse
Affiliation(s)
- Miroslav Pohanka
- Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 50001 Hradec Kralove, Czech Republic; E-Mail: ; Tel.: +420-973253091; Fax: +420-973253091
| |
Collapse
|
35
|
Nagino K, Shikinami K, Saito T, Harada Y. [Pharmacological and clinical profiles of galantamine (Reminyl(®))]. Nihon Yakurigaku Zasshi 2012; 138:122-6. [PMID: 21908940 DOI: 10.1254/fpj.138.122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
36
|
The nicotine metabolite, cotinine, attenuates glutamate (NMDA) antagonist-related effects on the performance of the five choice serial reaction time task (5C-SRTT) in rats. Biochem Pharmacol 2012; 83:941-51. [PMID: 22244928 DOI: 10.1016/j.bcp.2011.12.043] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 12/29/2011] [Accepted: 12/30/2011] [Indexed: 12/11/2022]
Abstract
Cotinine, the most predominant metabolite of nicotine in mammalian species, has a pharmacological half-life that greatly exceeds its precursor. However, until recently, relatively few studies had been conducted to systematically characterize the behavioral pharmacology of cotinine. Our previous work indicated that cotinine improves prepulse inhibition of the auditory startle response in rats in pharmacological impairment models and that it improves working memory in non-human primates. Here we tested the hypothesis that cotinine improves sustained attention in rats and attenuates behavioral alterations induced by the glutamate (NMDA) antagonist MK-801. The effects of acute subcutaneous (dose range 0.03-10.0 mg/kg) and chronic oral administration (2.0 mg/kg/day in drinking water) of cotinine were evaluated in fixed and variable stimulus duration (VSD) as well as variable intertrial interval (VITI) versions of a five choice serial reaction time task (5C-SRTT). The results indicated only subtle effects of acute cotinine (administered alone) on performance of the 5C-SRTT (e.g., decreases in timeout responses). However, depending on dose, acute treatment with cotinine attenuated MK-801-related impairments in accuracy and elevations in timeout responses, and it increased the number of completed trials. Moreover, chronic cotinine attenuated MK-801-related impairments in accuracy and it reduced premature and timeout responses when the demands of the task were increased (i.e., by presenting VSDs or VITIs in addition to administering MK-801). These data suggest that cotinine may represent a prototype for compounds that have therapeutic potential for neuropsychiatric disorders (i.e., by improving sustained attention and decreasing impulsive and compulsive behaviors), especially those characterized by glutamate receptor alterations.
Collapse
|
37
|
Busquet P, Capurro V, Cavalli A, Piomelli D, Reggiani A, Bertorelli R. Synergistic Effects of Galantamine and Memantine in Attenuating Scopolamine-Induced Amnesia in Mice. J Pharmacol Sci 2012; 120:305-9. [DOI: 10.1254/jphs.12166sc] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
|
38
|
Egea J, Martín-de-Saavedra MD, Parada E, Romero A, Del Barrio L, Rosa AO, García AG, López MG. Galantamine elicits neuroprotection by inhibiting iNOS, NADPH oxidase and ROS in hippocampal slices stressed with anoxia/reoxygenation. Neuropharmacology 2011; 62:1082-90. [PMID: 22085833 DOI: 10.1016/j.neuropharm.2011.10.022] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 10/25/2011] [Accepted: 10/31/2011] [Indexed: 01/24/2023]
Abstract
Galantamine is a drug currently used to treat Alzheimer's disease (AD); in this group of patients it has been observed that concomitant ischemic brain injury can accelerate their cognitive deficit. We have previously shown that galantamine can afford neuroprotection on in vitro and in vivo models related to brain ischemia. In this context, this study was planned to investigate the intracellular signaling pathways implicated in the protective effect of galantamine on an in vitro brain ischemia-reperfusion model, namely rat hippocampal slices subjected to oxygen and glucose deprivation (OGD) followed by reoxygenation. Galantamine protected hippocampal slices subjected to OGD in a concentration-dependent manner; at 15 μM, cell death was reduced to almost control levels. The neuroprotective effects of galantamine were reverted by mecamylamine and AG490, but not by atropine, indicating that nicotinic receptors and Jak2 participated in this action. Galantamine also prevented p65 translocation into the nucleus induced by OGD; this effect was also linked to nicotinic receptors and Jak2. Furthermore, galantamine reduced iNOS induction and production of NO caused by OGD via Jak2. ROS production by NADPH oxidase (NOX) activation was also inhibited by galantamine. In conclusion, galantamine afforded neuroprotection under OGD-reoxygenation conditions by activating a signaling pathway that involves nicotinic receptors, Jak2 and the consequent inhibition of NOX and NFκB/iNOS. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.
Collapse
Affiliation(s)
- J Egea
- Instituto Teófilo Hernando, Universidad Autónoma de Madrid, Spain.
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Gibbs RB, Chipman AM, Hammond R, Nelson D. Galanthamine plus estradiol treatment enhances cognitive performance in aged ovariectomized rats. Horm Behav 2011; 60:607-16. [PMID: 21889940 PMCID: PMC3210334 DOI: 10.1016/j.yhbeh.2011.08.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 08/12/2011] [Accepted: 08/13/2011] [Indexed: 11/30/2022]
Abstract
We hypothesize that beneficial effects of estradiol on cognitive performance diminish with age and time following menopause due to a progressive decline in basal forebrain cholinergic function. This study tested whether galanthamine, a cholinesterase inhibitor used to treat memory impairment associated with Alzheimer's disease, could enhance or restore estradiol effects on cognitive performance in aged rats that had been ovariectomized in middle-age. Rats were ovariectomized at 16-17 months of age. At 21-22 months of age rats began receiving daily injections of galanthamine (5mg/day) or vehicle. After one week, half of each group also received 17ß-estradiol administered subcutaneously. Rats were then trained on a delayed matching to position (DMP) T-maze task, followed by an operant stimulus discrimination/reversal learning task. Treatment with galanthamine+estradiol significantly enhanced the rate of DMP acquisition and improved short-term delay-dependent spatial memory performance. Treatment with galanthamine or estradiol alone was without significant effect. Effects were task-specific in that galanthamine+estradiol treatment did not significantly improve performance on the stimulus discrimination/reversal learning task. In fact, estradiol was associated with a significant increase in incorrect responses on this task after reversal of the stimulus contingency. In addition, treatments did not significantly affect hippocampal choline acetyltransferase activity or acetylcholine release. This may be an effect of age, or possibly is related to compensatory changes associated with long-term cholinesterase inhibitor treatment. The data suggest that treating with a cholinesterase inhibitor can enhance the effects of estradiol on acquisition of a DMP task by old rats following a long period of hormone deprivation. This could be of particular benefit to older women who have not used hormone therapy for many years and are beginning to show signs of mild cognitive impairment. Potential mechanisms for these effects are discussed.
Collapse
Affiliation(s)
- R B Gibbs
- University of Pittsburgh School of Pharmacy, 1004 Salk Hall, Pittsburgh, PA 15261, USA.
| | | | | | | |
Collapse
|
40
|
Atkinson AP, Baguet E, Galland N, Le Questel JY, Planchat A, Graton J. Structural Features and Hydrogen-Bond Properties of Galanthamine and Codeine: An Experimental and Theoretical Study. Chemistry 2011; 17:11637-49. [DOI: 10.1002/chem.201100475] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 06/21/2011] [Indexed: 11/07/2022]
|
41
|
Isik AT, Bozoglu E, Naharci MI, Kilic S. Evaluation of the effects of galantamine on cardiac function in elderly patients with Alzheimer's disease. ACTA ACUST UNITED AC 2011; 8:454-9. [PMID: 21335298 DOI: 10.1016/j.amjopharm.2010.09.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2010] [Indexed: 11/28/2022]
Abstract
BACKGROUND Galantamine, a cholinesterase inhibitor, is used as a first-line drug in the treatment of Alzheimer's disease (AD). However, it may have vagotonic effects, which may cause bradycardia and/or heart block in patients with or without a history of cardiac disease. OBJECTIVE The purpose of this study was to evaluate the effects of galantamine on electrophysiology and arterial blood pressure in elderly patients with AD. METHODS From March 2008 through August 2009, consecutive patients ≥65 years of age were approached for enrollment and underwent a comprehensive geriatric assessment. Patients with newly diagnosed AD who were enrolled in the study were treated with galantamine extended-release capsules using a 2- to 4-week titration schedule. The starting dosage was 8 mg once daily. After 2 to 4 weeks on the initial dosage, the dosage was increased to 16 mg once daily. After another 2 to 4 weeks, if galantamine was still well tolerated, the dosage was increased to 24 mg once daily. ECG parameters and blood pressure were recorded at baseline and at each galantamine dose level (8, 16, and 24 mg/d); blood pressure was measured once daily. The study lasted -4 months after baseline assessment. RESULTS Sixty-four patients with newly diagnosed AD were enrolled in the study, 51 of whom completed the study (28 women and 23 men; mean age, 78.5 years). No significant changes relative to baseline occurred in any of the ECG parameters or arterial blood pressure at any of the investigated dosages of galantamine. CONCLUSION None of the dosages of galantamine investigated in this study significantly altered ECG parameters or arterial blood pressure (relative to baseline) in these elderly patients with AD.
Collapse
Affiliation(s)
- Ahmet Turan Isik
- Division of Geriatrics, Department of Internal Medicine, Gulhane School of Medicine, Ankara, Turkey
| | | | | | | |
Collapse
|
42
|
Ago Y, Koda K, Takuma K, Matsuda T. Pharmacological aspects of the acetylcholinesterase inhibitor galantamine. J Pharmacol Sci 2011; 116:6-17. [PMID: 21498956 DOI: 10.1254/jphs.11r01cr] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Several lines of evidence suggest that cholinergic deficits may contribute to the pathophysiology of psychiatric disorders as well as Alzheimer's disease. There is growing clinical evidence that galantamine, currently used for the treatment of Alzheimer's disease, may improve cognitive dysfunction and psychiatric illness in schizophrenia, major depression, bipolar disorder, and alcohol abuse. Since galantamine is a rather weak acetylcholinesterase inhibitor, but has additional allosteric potentiating effects at nicotinic receptors, it affects not only cholinergic transmission but also other neurotransmitter systems such as monoamines, glutamate, and γ-aminobutyric acid (GABA) through its allosteric mechanism. It is likely that these effects may result in more beneficial effects. To understand the underlying mechanism for the clinical effectiveness of galantamine, neuropharmacological studies have been performed in animal models of several psychiatric disorders. These studies suggest that not only the nicotinic receptor-modulating properties but also the muscarinic receptor activation contribute to the antipsychotic effect and improvement of cognitive dysfunction by galantamine. This review summaries the current status on the pharmacology of galantamine, focusing on its effect on neurotransmitter release and pharmacological studies in animal models of psychiatric disorders.
Collapse
Affiliation(s)
- Yukio Ago
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
| | | | | | | |
Collapse
|
43
|
Pereira JD, Caricati-Neto A, Miranda-Ferreira R, Smaili SS, Godinho RO, de los Rios C, Léon R, Villaroya M, Samadi A, Marco-Contelles J, Jurkiewicz NH, Garcia AG, Jurkiewicz A. Effects of novel tacripyrines ITH12117 and ITH12118 on rat vas deferens contractions, calcium transients and cholinesterase activity. Eur J Pharmacol 2011; 660:411-9. [PMID: 21497158 DOI: 10.1016/j.ejphar.2011.03.042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 03/02/2011] [Accepted: 03/22/2011] [Indexed: 11/25/2022]
Abstract
We have recently synthesized a new series of hybrid compounds having the moieties of tacrine, a potent inhibitor of brain and peripheral acetylcholinesterase (AChE), and nimodipine, a blocker of L-type voltage-dependent calcium channels (VDCCs). These compounds were designed to target AChE and L calcium channels in the brain, as potential therapeutic agents in Alzheimer's disease. We performed the present study to determine the main peripheral side effects of two of these compounds, ITH12117 and ITH12118. We have here shown that in rat vas deferens these compounds inhibited AChE with a potency about 1000-fold lower than that of physostigmine or tacrine. Furthermore, the hybrid compounds enhanced contractions evoked by acetylcholine, with a potency about 100-fold lower than that of physostigmine or tacrine. Additionally, contractions induced by Ca2+ on depolarized vas deferens were blocked by nimodipine with greater efficacy, compared with ITH12117 and ITH12118. Compound ITH12118 (1 μM) caused a pronounced inhibition of the tonic (but not phasic) contraction elicited by electrical field stimulation. Furthermore, the same dose of nimodipine and ITH12118 blocked by 75% cytosolic Ca2+ elevations produced by acetylcholine, noradrenaline, or ATP. As a matter of comparison, we showed that rat brain cortex AChE was inhibited by ITH12118 with a potency 10 to 20-fold higher than that for vas deferens. This study shows that ITH12118 could be a paradigmatic multitarget compound having selective brain effects with smaller peripheral side effects. This may help to orient the search of new neuroprotective compounds with potential therapeutic application in Alzheimer's disease.
Collapse
|
44
|
Muthuraju S, Maiti P, Solanki P, Sharma AK, Pati S, Singh SB, Prasad D, Ilavazhagan G. Possible role of cholinesterase inhibitors on memory consolidation following hypobaric hypoxia of rats. Int J Neurosci 2011; 121:279-88. [PMID: 21348795 DOI: 10.3109/00207454.2011.556279] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
High altitude (HA) generates a deleterious effect known as hypobaric hypoxia (HBH). This causes severe physiological and psychological changes such as acute mountain sickness (AMS) and cognitive functions in terms of learning and memory. The present study has evaluated the effect of cholinesterase inhibitors on memory consolidation following HBH. Adult male Sprague Dawley rats (80-90 days old) with an average body weight of 250 ± 25 g were used. Rats were assessed memory consolidation by using Morris water maze (MWM) for 8 days. After assessment of memory consolidation, rats were then exposed to HBH in stimulated chamber for 7 days at 6,100 m. After exposure to HBH, the memory consolidation of rats has been assessed in MWM. The results showed that there was memory consolidation impairment in HBH-exposed rats as compared to normoxic rats in terms of time spent in quaradents, rings, and counters. The rats which have been treated with physostigmine (PHY) and galantamine (GAL) showed better time spent in quaradents, rings, and counters as compared with hypoxic rats. In conclusion, the cholinesterase inhibitors could ameliorate the impairment of memory consolidation following HBH.
Collapse
Affiliation(s)
- Sangu Muthuraju
- Neurobiology Division, Defence Institute of Physiology and Allied Sciences, Defence Research and Development Organization, Ministry of Defence, Government of India, Delhi, India
| | | | | | | | | | | | | | | |
Collapse
|
45
|
Ludwig J, Höffle-Maas A, Samochocki M, Luttmann E, Albuquerque EX, Fels G, Maelicke A. Localization by site-directed mutagenesis of a galantamine binding site on α7 nicotinic acetylcholine receptor extracellular domain. J Recept Signal Transduct Res 2010; 30:469-83. [PMID: 21062106 DOI: 10.3109/10799893.2010.505239] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Galantamine is an approved drug treatment for Alzheimer's disease. Initially identified as a weak cholinesterase inhibitor, we have established that galantamine mainly acts as an 'allosterically potentiating ligand (APL)' of nicotinic acetylcholine receptors (nAChR). Meanwhile other 'positive allosteric modulators (PAM)' of nAChR channel activity have been discovered, and for one of them a binding site within the transmembrane domain has been proposed. Here we show, by performing site-directed mutagenesis studies of ectopically expressed chimeric chicken α7/mouse 5-hydroxytryptamine 3 receptor-channel complex, in combination with whole-cell current measurements, in the presence and absence of galantamine, that the APL binding site is different from the proposed PAM binding site. We demonstrate that residues T197, I196, and F198 of ß-strand 10 represent major elements of the galantamine binding site. Residue K123, earlier suggested as being 'close to' the APL binding site, is not part of this site but rather appears to play a role in coupling of agonist binding to channel opening and closing. Our data confirm our earlier results that the galantamine binding site is different from the ACh binding site. Both sites are in close proximity and hence may influence each other in a synergistic fashion. Other interesting areas identified in the present study are a 'hinge' region around and containing residues F122, K123, and K143 possibly being involved in relaying the signal of agonist binding to gating of the transmembrane channel, and a 'folding centre', with P119 as the dominating residue, that crucially positions the agonist binding site with respect to the hinge region.
Collapse
|
46
|
Galantamine ameliorates the impairment of recognition memory in mice repeatedly treated with methamphetamine: involvement of allosteric potentiation of nicotinic acetylcholine receptors and dopaminergic-ERK1/2 systems. Int J Neuropsychopharmacol 2010; 13:1343-54. [PMID: 20219155 DOI: 10.1017/s1461145710000222] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Galantamine, a drug used to treat Alzheimer's disease, inhibits acetylcholinesterase (AChE) and allosterically modulates nicotinic acetylcholine receptors (nAChRs) resulting in stimulation of catecholamine neurotransmission. In this study, we investigated whether galantamine exerts cognitive-improving effects through the allosteric modulation of nAChRs in an animal model of methamphetamine (Meth) psychosis. The mice treated with Meth (1 mg/kg.d) for 7 d showed memory impairment in a novel object recognition test. Galantamine (3 mg/kg) ameliorated the memory impairment, and it increased the extracellular dopamine release in the prefrontal cortex (PFC) of Meth-treated mice. Donepezil, an AChE inhibitor (1 mg/kg) increased the extracellular ACh release in the PFC, whereas it had no effect on the memory impairment in Meth-treated mice. The nAChR antagonist, mecamylamine, and dopamine D1 receptor antagonist, SCH 23390, blocked the ameliorating effect of galantamine on Meth-induced memory impairment, whereas the muscarinic AChR antagonist, scopolamine, had no effect. The effects of galantamine on extracellular dopamine release were also antagonized by mecamylamine. Galantamine attenuated the defect of the novelty-induced activation of extracellular signal-regulated kinase 1/2 (ERK1/2). The ameliorating effect of galantamine on recognition memory in Meth-treated mice was negated by microinjection of an ERK inhibitor, PD98059, into the PFC. These results suggest that the ameliorating effect of galantamine on Meth-induced memory impairment is associated with indirect activation of dopamine D1 receptor-ERK1/2 following augmentation with dopaminergic neurotransmission in the PFC through the allosteric activation of nAChRs. Galantamine could be a useful therapeutic agent for treating cognitive deficits in schizophrenia/Meth psychosis, as well as Alzheimer's disease.
Collapse
|
47
|
Vicente MI, Costa PF, Lima PA. Galantamine inhibits slowly inactivating K+ currents with a dual dose–response relationship in differentiated N1E-115 cells and in CA1 neurones. Eur J Pharmacol 2010; 634:16-25. [DOI: 10.1016/j.ejphar.2010.02.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 01/26/2010] [Accepted: 02/13/2010] [Indexed: 11/15/2022]
|
48
|
Penner J, Rupsingh R, Smith M, Wells JL, Borrie MJ, Bartha R. Increased glutamate in the hippocampus after galantamine treatment for Alzheimer disease. Prog Neuropsychopharmacol Biol Psychiatry 2010; 34:104-10. [PMID: 19833161 DOI: 10.1016/j.pnpbp.2009.10.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Revised: 09/24/2009] [Accepted: 10/06/2009] [Indexed: 10/20/2022]
Abstract
Galantamine is a cholinesterase inhibitor and allosteric potentiating ligand modulating presynaptic nicotinic acetylcholine receptors that is used in the treatment of Alzheimer disease (AD). The purpose of this study was to determine if galantamine treatment would result in detectable hippocampal metabolite changes that correlated with changes in cognition, as measured by the Mini-Mental State Examination (MMSE) and the Alzheimer Disease Assessment Scale-cognitive subscale (ADAS-cog). Short echo-time proton magnetic resonance (MR) spectra were acquired from within the right hippocampus of ten patients using a 4 Tesla magnetic resonance imaging (MRI) scanner. Spectra were used to quantify absolute metabolite levels for N-acetylaspartate (NAA), glutamate (Glu), choline (Cho), creatine (Cr), and myo-inositol (mI). Patient scans and cognitive tests were performed before and 4 months after beginning galantamine treatment, which consisted of an 8 mg daily dose for the first month and a 16 mg daily dose for the remaining three months. The levels of Glu, Glu/Cr, and Glu/NAA increased after four months of treatment, while there were no changes in MMSE or ADAS-cog scores. Additionally, changes (Delta) in Glu over the four months (DeltaGlu) correlated with DeltaNAA, and Delta(Glu/Cr) correlated with DeltaMMSE scores. Increased Glu and the ratio of Glu to Cr measured by MR spectroscopy after galantamine treatment were associated with increased cognitive performance. The increase in Glu may be related to the action of galantamine as an allosteric potentiating ligand for presynaptic nicotinic acetylcholine receptors, which increases glutamatergic neurotransmission.
Collapse
Affiliation(s)
- Jacob Penner
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, PO Box 5015, 100 Perth Drive, London, Ontario, Canada
| | | | | | | | | | | |
Collapse
|
49
|
Luttmann E, Ludwig J, Höffle-Maas A, Samochocki M, Maelicke A, Fels G. Structural model for the binding sites of allosterically potentiating ligands on nicotinic acetylcholine receptors. ChemMedChem 2010; 4:1874-82. [PMID: 19739198 DOI: 10.1002/cmdc.200900320] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Current treatments of Alzheimer's disease include the allosteric potentiation of nicotinic acetylcholine receptor (nAChR) response. The location of the binding site for allosteric potentiating ligands (APLs) within the receptor is not yet fully understood. Based on homology models for the ligand binding domain of human alpha7, human alpha4beta2, and chicken alpha7 receptors, as well as blind docking experiments with galanthamine, physostigmine, codeine, and 5HT, we identified T197 as an essential element of the APL binding site at the outer surface of the ligand binding domain (LBD) of nAChR. We also found the previously known galanthamine binding site in the region of K123 at the inside of the receptor funnel, which, however, was shown to not be part of the APL site. Our results are verified by site-directed mutagenesis and electrophysiological experiments, and suggest that APL and ACh bind to different sites on nicotinic receptors and that allosteric potentiation may arise from a direct interplay between both these sites.
Collapse
Affiliation(s)
- Edgar Luttmann
- University of Paderborn, Department of Chemistry, Germany
| | | | | | | | | | | |
Collapse
|
50
|
Nicotine stimulation of the medulla increases blood flow of the common carotid artery in cats. Auton Neurosci 2010; 152:49-54. [DOI: 10.1016/j.autneu.2009.08.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2009] [Revised: 08/28/2009] [Accepted: 08/28/2009] [Indexed: 11/22/2022]
|