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Al-Smadi S, Padros A, Goss GG, Dickson CT. The translational inhibitor and amnestic agent emetine also suppresses ongoing hippocampal neural activity similarly to other blockers of protein synthesis. Hippocampus 2024; 34:380-392. [PMID: 38785391 DOI: 10.1002/hipo.23611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 04/19/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024]
Abstract
The consolidation of memory is thought to ultimately depend on the synthesis of new proteins, since translational inhibitors such as anisomycin and cycloheximide adversely affect the permanence of long-term memory. However, when applied directly in brain, these agents also profoundly suppress neural activity to an extent that is directly correlated to the degree of protein synthesis inhibition caused. Given that neural activity itself is likely to help mediate consolidation, this finding is a serious criticism of the strict de novo protein hypothesis of memory. Here, we test the neurophysiological effects of another translational inhibitor, emetine. Unilateral intra-hippocampal infusion of emetine suppressed ongoing local field and multiunit activity at ipsilateral sites as compared to the contralateral hippocampus in a fashion that was positively correlated to the degree of protein synthesis inhibition as confirmed by autoradiography. This suppression of activity was also specific to the circumscribed brain region in which protein synthesis inhibition took place. These experiments provide further evidence that ongoing protein synthesis is necessary and fundamental for neural function and suggest that the disruption of memory observed in behavioral experiments using translational inhibitors may be due, in large part, to neural suppression.
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Affiliation(s)
- S Al-Smadi
- Department of Physiology, University of Alberta, Edmonton, Canada
| | - A Padros
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| | - G G Goss
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
| | - C T Dickson
- Department of Physiology, University of Alberta, Edmonton, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
- Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, Canada
- Department of Psychology, University of Alberta, Edmonton, Canada
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2
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Bin Ibrahim MZ, Wang Z, Sajikumar S. Synapses tagged, memories kept: synaptic tagging and capture hypothesis in brain health and disease. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230237. [PMID: 38853570 PMCID: PMC11343274 DOI: 10.1098/rstb.2023.0237] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 01/29/2024] [Accepted: 02/13/2024] [Indexed: 06/11/2024] Open
Abstract
The synaptic tagging and capture (STC) hypothesis lays the framework on the synapse-specific mechanism of protein synthesis-dependent long-term plasticity upon synaptic induction. Activated synapses will display a transient tag that will capture plasticity-related products (PRPs). These two events, tag setting and PRP synthesis, can be teased apart and have been studied extensively-from their electrophysiological and pharmacological properties to the molecular events involved. Consequently, the hypothesis also permits interactions of synaptic populations that encode different memories within the same neuronal population-hence, it gives rise to the associativity of plasticity. In this review, the recent advances and progress since the experimental debut of the STC hypothesis will be shared. This includes the role of neuromodulation in PRP synthesis and tag integrity, behavioural correlates of the hypothesis and modelling in silico. STC, as a more sensitive assay for synaptic health, can also assess neuronal aberrations. We will also expound how synaptic plasticity and associativity are altered in ageing-related decline and pathological conditions such as juvenile stress, cancer, sleep deprivation and Alzheimer's disease. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.
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Affiliation(s)
- Mohammad Zaki Bin Ibrahim
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore117597, Singapore
- Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore119077, Singapore
| | - Zijun Wang
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore117597, Singapore
- Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore119077, Singapore
| | - Sreedharan Sajikumar
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore117597, Singapore
- Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore119077, Singapore
- Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore117597, Singapore
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3
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Jana A, Naga R, Saha S, Griñán-Ferré C, Banerjee DR. Integration of ligand and structure-based pharmacophore screening for the identification of novel natural leads against Euchromatic histone lysine methyltransferase 2 (EHMT2/G9a). J Biomol Struct Dyn 2024; 42:3535-3562. [PMID: 37216299 DOI: 10.1080/07391102.2023.2213346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 05/08/2023] [Indexed: 05/24/2023]
Abstract
Herein, we report a blended ligand and structure-based pharmacophore screening approach to identify new natural leads against the Protein Lysine Methyltransferase 2 (EHMT2/G9a). The EHMT2/G9a has been associated with Cancer, Alzheimer's, and aging and is considered an emerging drug target having no clinically passed inhibitor. Purposefully, we developed the ligand-based pharmacophore (Pharmacophore-L) based on the common features of known inhibitors and the structure-based pharmacophore (Pharmacophore-S) based on the interaction profile of available crystal structures. The Pharmacophore-L and Pharmacophore-S were subjected to multiple tiers of validations and utilized in combination for the screening of total 741543 compounds coming from multiple databases. Additional layers of stringency were applied in the screening process to test drug-likeness (using Lipinski's rule, Veber's rule, SMARTS and ADMET filtration), to rule out any toxicity (TOPKAT analysis). The interaction profiles, stabilities, and comparative analysis against the reference were carried out by flexible docking, MD simulation, and MM-GBSA analysis, which finally led to three leads as potential inhibitors of G9a.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Abhisek Jana
- Department of Chemistry, National Institute of Technology Durgapur, Durgapur, India
| | - Rahul Naga
- Department of Biotechnology, National Institute of Technology Durgapur, Durgapur, India
| | - Sougata Saha
- Department of Biotechnology, National Institute of Technology Durgapur, Durgapur, India
| | - Christian Griñán-Ferré
- Department of Pharmacology and Therapeutic Chemistry, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Deb Ranjan Banerjee
- Department of Chemistry, National Institute of Technology Durgapur, Durgapur, India
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Gao J, Liu W, Liu J, Hao N, Pei J, Zhang L. The Role of Acetylation and Methylation of Rat Hippocampal Histone H3 in the Mechanism of Aluminum-Induced Neurotoxicity. Neurochem Res 2024; 49:441-452. [PMID: 37897558 DOI: 10.1007/s11064-023-04045-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 10/09/2023] [Accepted: 10/14/2023] [Indexed: 10/30/2023]
Abstract
Aluminum is a known neurotoxin and a major environmental contributor to neurodegenerative diseases such as Alzheimer's disease (AD). We uesd a subchronic aluminum chloride exposure model in offspring rats by continuously treating them with AlCl3 solution from the date of birth until day 90 in this research. Then evaluated the neurobehavioral changes in rats, observed the ultrastructural changes of hippocampal synapses and neurons, and examined the level of hippocampal acetylated histone H3 (H3ac), the activity and protein expression of hippocampal HAT1 and G9a, and the protein expression level of H3K9 dimethylation (H3K9me2). The findings demonstrated that aluminum-treated offspring rats had impaired learning and memory abilities as well as ultrastructural alterations in hippocampal synapses and neurons. The level of histone H3ac was decreased along with decreased protein expression and activity of HAT1, while level of H3K9me2 was increased along with increased protein expression and activity of G9a.
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Affiliation(s)
- Jie Gao
- Department of Maternal, Child and Adolescent Health, School of Public Health, Shenyang Medical College, Shenyang, 110034, Liaoning Province, P. R. China
| | - Wei Liu
- Department of Maternal, Child and Adolescent Health, School of Public Health, Shenyang Medical College, Shenyang, 110034, Liaoning Province, P. R. China
| | - Jiaqi Liu
- Department of Maternal, Child and Adolescent Health, School of Public Health, Shenyang Medical College, Shenyang, 110034, Liaoning Province, P. R. China
| | - Niping Hao
- Department of Maternal, Child and Adolescent Health, School of Public Health, Shenyang Medical College, Shenyang, 110034, Liaoning Province, P. R. China
| | - Jing Pei
- Department of Maternal, Child and Adolescent Health, School of Public Health, Shenyang Medical College, Shenyang, 110034, Liaoning Province, P. R. China
| | - Lifeng Zhang
- Department of Maternal, Child and Adolescent Health, School of Public Health, Shenyang Medical College, Shenyang, 110034, Liaoning Province, P. R. China.
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5
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Zhao Y, Ai W, Zheng J, Hu X, Zhang L. A bibliometric and visual analysis of epigenetic research publications for Alzheimer's disease (2013-2023). Front Aging Neurosci 2024; 16:1332845. [PMID: 38292341 PMCID: PMC10824959 DOI: 10.3389/fnagi.2024.1332845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 01/02/2024] [Indexed: 02/01/2024] Open
Abstract
Background Currently, the prevalence of Alzheimer's disease (AD) is progressively rising, particularly in developed nations. There is an escalating focus on the onset and progression of AD. A mounting body of research indicates that epigenetics significantly contributes to AD and holds substantial promise as a novel therapeutic target for its treatment. Objective The objective of this article is to present the AD areas of research interest, comprehend the contextual framework of the subject research, and investigate the prospective direction for future research development. Methods ln Web of Science Core Collection (WOSCC), we searched documents by specific subject terms and their corresponding free words. VOSviewer, CiteSpace and Scimago Graphica were used to perform statistical analysis on measurement metrics such as the number of published papers, national cooperative networks, publishing countries, institutions, authors, co-cited journals, keywords, and visualize networks of related content elements. Results We selected 1,530 articles from WOSCC from January 2013 to June 2023 about epigenetics of AD. Based on visual analysis, we could get that China and United States were the countries with the most research in this field. Bennett DA was the most contributed and prestigious scientist. The top 3 cited journals were Journal of Alzheimer's Disease, Neurobiology of Aging and Molecular Neurobiology. According to the analysis of keywords and the frequency of citations, ncRNAs, transcription factor, genome, histone modification, blood DNA methylation, acetylation, biomarkers were hot research directions in AD today. Conclusion According to bibliometric analysis, epigenetic research in AD was a promising research direction, and epigenetics had the potential to be used as AD biomarkers and therapeutic targets.
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Affiliation(s)
- YaPing Zhao
- School of Clinical Medicine, Chengdu Medical College, Chengdu, China
| | - WenJing Ai
- School of Clinical Medicine, Chengdu Medical College, Chengdu, China
| | - JingFeng Zheng
- School of Clinical Medicine, Chengdu Medical College, Chengdu, China
| | - XianLiang Hu
- Chengdu Eighth People’s Hospital, Geriatric Hospital of Chengdu Medical College, Chengdu, China
| | - LuShun Zhang
- Sichuan Key Laboratory of Development and Regeneration, Department of Neurobiology, Chengdu Medical College, Chengdu, China
- Department of Pathology and Pathophysiology, Chengdu Medical College, Chengdu, China
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Jana A, Bellver-Sanchis A, Griñán-Ferré C, Banerjee DR. Repurposing of Raltitrexed as an Effective G9a/EHMT2 Inhibitor and Promising Anti-Alzheimer's Agent. ACS Med Chem Lett 2023; 14:1531-1536. [PMID: 37974951 PMCID: PMC10641905 DOI: 10.1021/acsmedchemlett.3c00344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 10/09/2023] [Indexed: 11/19/2023] Open
Abstract
Herein, we report for the first time the G9a/EHMT2 inhibition and anti-Alzheimer's activities of the drug raltitrexed. G9a is a lysine methyltransferase that mainly dimethylates the H3K9 of chromatin, which triggers the repression of genes epigenetically, leading to various diseased conditions, including Alzheimer's disease (AD). First, we demonstrate that raltitrexed inhibits G9a at 120 nM. Moreover, raltitrexed lowers the total H3K9me2/H3K9 levels in AD transgenic C. elegans CL2006 worms, indicating that raltitrexed targets G9a directly. As toxicity is the bottleneck in G9a drug discovery, we conducted detailed in silico toxicity (TOPKAT) analyses of raltitrexed and measured the food consumption by C. elegans, demonstrating that raltitrexed's toxicity/function range is safe for the worm's growth. Moreover, we demonstrate that raltitrexed enhances the locomotive function of worms dose-dependently. Finally, we show that raltitrexed reduced the Aβ aggregates in worms up to 47%, highlighting the potential of raltitrexed in AD treatment.
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Affiliation(s)
- Abhisek Jana
- Department
of Chemistry, National Institute of Technology
Durgapur, M G Avenue, Durgapur-713209 , West Bengal, India
| | - Aina Bellver-Sanchis
- Pharmacology
Section, Department of Pharmacology, Toxicology and Therapeutic Chemistry,
Faculty of Pharmacy and Food Sciences, Institute of Neuroscience, Universitat de Barcelona (NeuroUB), Av. Joan XXIII 27−31, 08028 Barcelona, Spain
| | - Christian Griñán-Ferré
- Pharmacology
Section, Department of Pharmacology, Toxicology and Therapeutic Chemistry,
Faculty of Pharmacy and Food Sciences, Institute of Neuroscience, Universitat de Barcelona (NeuroUB), Av. Joan XXIII 27−31, 08028 Barcelona, Spain
- Centro
de Investigación en Red, Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Deb Ranjan Banerjee
- Department
of Chemistry, National Institute of Technology
Durgapur, M G Avenue, Durgapur-713209 , West Bengal, India
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Callis TB, Garrett TR, Montgomery AP, Danon JJ, Kassiou M. Recent Scaffold Hopping Applications in Central Nervous System Drug Discovery. J Med Chem 2022; 65:13483-13504. [PMID: 36206553 DOI: 10.1021/acs.jmedchem.2c00969] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The concept of bioisosterism and the implementation of bioisosteric replacement is fundamental to medicinal chemistry. The exploration of bioisosteres is often used to probe key structural features of candidate pharmacophores and enhance pharmacokinetic properties. As the understanding of bioisosterism has evolved, capabilities to undertake more ambitious bioisosteric replacements have emerged. Scaffold hopping is a broadly used term in the literature referring to a variety of different bioisosteric replacement strategies, ranging from simple heterocyclic replacements to topological structural overhauls. In this work, we have highlighted recent applications of scaffold hopping in the central nervous system drug discovery space. While we have highlighted the benefits of using scaffold hopping approaches in central nervous system drug discovery, these are also widely applicable to other medicinal chemistry fields. We also recommend a shift toward the use of more refined and meaningful terminology within the realm of scaffold hopping.
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Affiliation(s)
- Timothy B Callis
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Taylor R Garrett
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | | | - Jonathan J Danon
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Michael Kassiou
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
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Bellver-Sanchis A, Singh Choudhary B, Companys-Alemany J, Sukanya, Ávila-López PA, Martínez Rodríguez AL, Brea Floriani JM, Malik R, Pallàs M, Pérez B, Griñán-Ferré C. Structure-Based Virtual Screening and in vitro and in vivo Analyses Revealed Potent Methyltransferase G9a Inhibitors as Prospective Anti-Alzheimer's Agents. ChemMedChem 2022; 17:e202200002. [PMID: 35413149 PMCID: PMC9401600 DOI: 10.1002/cmdc.202200002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 04/11/2022] [Indexed: 11/20/2022]
Abstract
G9a is a lysine methyltransferase able to di-methylate lysine 9 of histone H3, promoting the repression of genes involved in learning and memory. Novel strategies based on synthesizing epigenetic drugs could regulate gene expression through histone post-translational modifications and effectively treat neurodegenerative diseases, like Alzheimer's disease (AD). Here, potential G9a inhibitors were identified using a structure-based virtual screening against G9a, followed by in vitro and in vivo screenings. First, screening methods with the AD transgenic Caenorhabditis elegans strain CL2006, showed that the toxicity/function range was safe and recovered age-dependent paralysis. Likewise, we demonstrated that the best candidates direct target G9a by reducing H3 K9me2 in the CL2006 strain. Further characterization of these compounds involved the assessment of the blood-brain barrier-permeability and impact on amyloid-β aggregation, showing promising results. Thus, we present a G9a inhibitor candidate, F, with a novel and potent structure, providing both leads in G9a inhibitor design and demonstrating their participation in reducing AD pathology.
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Affiliation(s)
- Aina Bellver-Sanchis
- Pharmacology Section, Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, Institute of Neuroscience, Universitat de Barcelona (NeuroUB), Av. Joan XXIII 27-31, 08028, Barcelona, Spain
| | - Bhanwar Singh Choudhary
- Department of Pharmacy, Central University of Rajasthan, Bandarsindari, Ajmer, 305817, India
- Department of Pharmaceutical Chemistry and Quality Assurance, Shree S. K. Patel College of Pharmaceutical Education and Research, Ganpat University, Mehsana, Gujarat, 384012, India
| | - Júlia Companys-Alemany
- Pharmacology Section, Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, Institute of Neuroscience, Universitat de Barcelona (NeuroUB), Av. Joan XXIII 27-31, 08028, Barcelona, Spain
| | - Sukanya
- Department of Pharmacy, Central University of Rajasthan, Bandarsindari, Ajmer, 305817, India
| | - Pedro A Ávila-López
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Antón Leandro Martínez Rodríguez
- Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, Universidad de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - Jose Manuel Brea Floriani
- Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, Universidad de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - Ruchi Malik
- Department of Pharmacy, Central University of Rajasthan, Bandarsindari, Ajmer, 305817, India
| | - Mercè Pallàs
- Pharmacology Section, Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, Institute of Neuroscience, Universitat de Barcelona (NeuroUB), Av. Joan XXIII 27-31, 08028, Barcelona, Spain
| | - Belén Pérez
- Department of Pharmacology, Therapeutic and Toxicology, Universitat Autònoma de Barcelona, 08193, Barcelona, Spain
| | - Christian Griñán-Ferré
- Pharmacology Section, Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, Institute of Neuroscience, Universitat de Barcelona (NeuroUB), Av. Joan XXIII 27-31, 08028, Barcelona, Spain
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