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Althobaiti NA, Al-Abbas NS, Alsharif I, Albalawi AE, Almars AI, Basabrain AA, Jafer A, Ellatif SA, Bauthman NM, Almohaimeed HM, Soliman MH. Gadd45A-mediated autophagy regulation and its impact on Alzheimer's disease pathogenesis: Deciphering the molecular Nexus. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167353. [PMID: 39004381 DOI: 10.1016/j.bbadis.2024.167353] [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: 12/30/2023] [Revised: 06/18/2024] [Accepted: 07/08/2024] [Indexed: 07/16/2024]
Abstract
BACKGROUND The growth arrest and DNA damage-inducible 45 (Gadd45) gene has been implicated in various central nervous system (CNS) functions, both normal and pathological, including aging, memory, and neurodegenerative diseases. In this study, we examined whether Gadd45A deletion triggers pathways associated with neurodegenerative diseases including Alzheimer's disease (AD). METHODS Utilizing transcriptome data from AD-associated hippocampus samples, we identified Gadd45A as a pivotal regulator of autophagy. Comprehensive analyses, including Gene Ontology enrichment and protein-protein interaction network assessments, highlighted Cdkn1A as a significant downstream target of Gadd45A. Experimental validation confirmed Gadd45A's role in modulating Cdkn1A expression and autophagy levels in hippocampal cells. We also examined the effects of autophagy on hippocampal functions and proinflammatory cytokine secretion. Additionally, a murine model was employed to validate the importance of Gadd45A in neuroinflammation and AD pathology. RESULTS Our study identified 20 autophagy regulatory factors associated with AD, with Gadd45A emerging as a critical regulator. Experimental findings demonstrated that Gadd45A influences hippocampal cell fate by reducing Cdkn1A expression and suppressing autophagic activity. Comparisons between wild-type (WT) and Gadd45A knockout (Gadd45A-/-) mice revealed that Gadd45A-/- mice exhibited significant cognitive impairments, including deficits in working and spatial memory, increased Tau hyperphosphorylation, and elevated levels of kinases involved in Tau phosphorylation in the hippocampus. Additionally, Gadd45A-/- mice showed significant increases in pro-inflammatory cytokines and decreases autophagy markers in the brain. Neurotrophin levels and dendritic spine length were also reduced in Gadd45A-/- mice, likely contributing to the observed cognitive deficits. CONCLUSIONS These findings support the direct involvement of the Gadd45A gene in AD pathogenesis, and enhancing the expression of Gadd45A may represent a promising therapeutic strategy for the treatment of AD.
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Affiliation(s)
- Norah A Althobaiti
- Biology Department, College of Science and Humanities, Shaqra University, Saudi Arabia
| | - Nouf S Al-Abbas
- Department of Biology, Jamoum University College, Umm Al-Qura University, 21955 Makkah, Saudi Arabia
| | - Ifat Alsharif
- Department of Biology, Jamoum University College, Umm Al-Qura University, 21955 Makkah, Saudi Arabia
| | - Aishah E Albalawi
- Faculty of Science, Department of Biology, University of Tabuk, Tabuk 47913, Saudi Arabia
| | - Amany I Almars
- Department of Medial Laboratory Sciences, Faculty of Applied Medical Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Ammar A Basabrain
- Department of Medial Laboratory Sciences, Faculty of Applied Medical Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; Hematology Research Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Ayman Jafer
- Department of Medial Laboratory Sciences, Faculty of Applied Medical Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Sawsan Abd Ellatif
- Bioprocess Development Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), City of Scientific Research and Technological Applications (SRTA-City), Alexandria 21934, Egypt
| | - Nuha M Bauthman
- Department of Obstetric & Gynecology, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Hailah M Almohaimeed
- Department of Basic Science, College of Medicine, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Mona H Soliman
- Botany and Microbiology Department, Faculty of Science, Cairo University, Giza 12613, Egypt; Biology Department, Faculty of Science, Taibah University, Al-Sharm, Yanbu El-Bahr, Yanbu 46429, Saudi Arabia.
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2
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Griñán-Ferré C, Jarne-Ferrer J, Bellver-Sanchis A, Ribalta-Vilella M, Barroso E, Salvador JM, Jurado-Aguilar J, Palomer X, Vázquez-Carrera M, Pallàs M. Deletion of Gadd45a Expression in Mice Leads to Cognitive and Synaptic Impairment Associated with Alzheimer's Disease Hallmarks. Int J Mol Sci 2024; 25:2595. [PMID: 38473843 DOI: 10.3390/ijms25052595] [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: 01/10/2024] [Revised: 02/10/2024] [Accepted: 02/18/2024] [Indexed: 03/14/2024] Open
Abstract
Gadd45 genes have been implicated in survival mechanisms, including apoptosis, autophagy, cell cycle arrest, and DNA repair, which are processes related to aging and life span. Here, we analyzed if the deletion of Gadd45a activates pathways involved in neurodegenerative disorders such as Alzheimer's Disease (AD). This study used wild-type (WT) and Gadd45a knockout (Gadd45a-/-) mice to evaluate AD progression. Behavioral tests showed that Gadd45a-/- mice presented lower working and spatial memory, pointing out an apparent cognitive impairment compared with WT animals, accompanied by an increase in Tau hyperphosphorylation and the levels of kinases involved in its phosphorylation in the hippocampus. Moreover, Gadd45a-/- animals significantly increased the brain's pro-inflammatory cytokines and modified autophagy markers. Notably, neurotrophins and the dendritic spine length of the neurons were reduced in Gadd45a-/- mice, which could contribute to the cognitive alterations observed in these animals. Overall, these findings demonstrate that the lack of the Gadd45a gene activates several pathways that exacerbate AD pathology, suggesting that promoting this protein's expression or function might be a promising therapeutic strategy to slow down AD progression.
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Affiliation(s)
- Christian Griñán-Ferré
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, University of Barcelona, Avda. Joan XXIII 27, 08028 Barcelona, Spain
- Institute of Neurosciences of the University of Barcelona, University of Barcelona, 08035 Barcelona, Spain
- Spanish Biomedical Research Center in Neurodegenerative Diseases (CIBERNED)-National Institute of Health Carlos III, 28029 Madrid, Spain
| | - Júlia Jarne-Ferrer
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, University of Barcelona, Avda. Joan XXIII 27, 08028 Barcelona, Spain
- Institute of Neurosciences of the University of Barcelona, University of Barcelona, 08035 Barcelona, Spain
| | - Aina Bellver-Sanchis
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, University of Barcelona, Avda. Joan XXIII 27, 08028 Barcelona, Spain
- Institute of Neurosciences of the University of Barcelona, University of Barcelona, 08035 Barcelona, Spain
| | - Marta Ribalta-Vilella
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, University of Barcelona, Avda. Joan XXIII 27, 08028 Barcelona, Spain
- Institute of Neurosciences of the University of Barcelona, University of Barcelona, 08035 Barcelona, Spain
| | - Emma Barroso
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, University of Barcelona, Avda. Joan XXIII 27, 08028 Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona, 08028 Barcelona, Spain
- Spanish Biomedical Research Center in Diabetes and Associated Metabolic Diseases (CIBERDEM)-National Institute of Health Carlos III, 28029 Madrid, Spain
- Pediatric Research Institute-Hospital Sant Joan de Déu, Esplugues de Llobregat, 08950 Barcelona, Spain
| | - Jesús M Salvador
- Department of Immunology and Oncology, National Center for Biotechnology/CSIC, 28049 Madrid, Spain
| | - Javier Jurado-Aguilar
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, University of Barcelona, Avda. Joan XXIII 27, 08028 Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona, 08028 Barcelona, Spain
- Spanish Biomedical Research Center in Diabetes and Associated Metabolic Diseases (CIBERDEM)-National Institute of Health Carlos III, 28029 Madrid, Spain
- Pediatric Research Institute-Hospital Sant Joan de Déu, Esplugues de Llobregat, 08950 Barcelona, Spain
| | - Xavier Palomer
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, University of Barcelona, Avda. Joan XXIII 27, 08028 Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona, 08028 Barcelona, Spain
- Spanish Biomedical Research Center in Diabetes and Associated Metabolic Diseases (CIBERDEM)-National Institute of Health Carlos III, 28029 Madrid, Spain
- Pediatric Research Institute-Hospital Sant Joan de Déu, Esplugues de Llobregat, 08950 Barcelona, Spain
| | - Manuel Vázquez-Carrera
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, University of Barcelona, Avda. Joan XXIII 27, 08028 Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona, 08028 Barcelona, Spain
- Spanish Biomedical Research Center in Diabetes and Associated Metabolic Diseases (CIBERDEM)-National Institute of Health Carlos III, 28029 Madrid, Spain
- Pediatric Research Institute-Hospital Sant Joan de Déu, Esplugues de Llobregat, 08950 Barcelona, Spain
| | - Mercè Pallàs
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, University of Barcelona, Avda. Joan XXIII 27, 08028 Barcelona, Spain
- Institute of Neurosciences of the University of Barcelona, University of Barcelona, 08035 Barcelona, Spain
- Spanish Biomedical Research Center in Neurodegenerative Diseases (CIBERNED)-National Institute of Health Carlos III, 28029 Madrid, Spain
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Furman M, Sihotsky V, Virag M, Kopolovets I, Nemethova M, Mucha R. Quantitative analysis of selected genetic markers of induced brain stroke ischemic tolerance detected in human blood. Brain Res 2023; 1821:148590. [PMID: 37739332 DOI: 10.1016/j.brainres.2023.148590] [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: 06/20/2023] [Revised: 09/14/2023] [Accepted: 09/19/2023] [Indexed: 09/24/2023]
Abstract
A brain stroke is a serious disease and the second leading cause of death in the European Union. Carotid stenosis accounts for 15% of all ischemic cerebral strokes. However, there is currently no effective screening for carotid disease. Analysis of the DNA from peripheral blood is increasingly being used for several disease diagnoses. The potentially beneficial therapeutic method of inducing tissue tolerance to ischemia has so far been studied mainly in animal models. The aim of this study is to investigate changes in the gene expression of selected markers of brain ischemia during carotid endarterectomy, considered in this study as an activator of ischemic tolerance. During the carotid endarterectomy, there is a short-term occlusion of the internal carotid artery. Using the RT-qPCR method, we detected changes in the early identified gene markers of brain ischemia (ADM, CDKN1A, GADD45G, IL6, TM4SF1) in peripheral blood during sub lethal cerebral ischemia caused by carotid endarterectomy. Patients underwenting surgical procedure were divided into three groups: asymptomatic, symptomatic, and those who underwent carotid endarterectomy after an acute stroke. The results were compared to a negative/control group. Carotid endarterectomy had an impact on the expression of all monitored biomarkers. We observed statistically significant changes (p value 0.05-0.001) when comparing the groups among themselves, as well as the presence of ischemic tolerance of brain tissue to ischemic attacks. In conclusion, ADM, GADD45G, and TM4SF1 were affected in symptomatic patients, GADD45G and IL6 in acute patients, and CDKN1A and ADM in asymptomatic group after application of carotid endarterectomy.
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Affiliation(s)
- Marek Furman
- Institute of Neurobiology of Biomedical Research Center, Slovak Academy of Sciences, Soltesovej 4, 040 01 Kosice, Slovakia
| | - Vladimir Sihotsky
- Eastern Slovak Institute of Cardiovascular Diseases and Faculty of Medicine, Pavol Jozef Safarik University, Kosice, Ondavska 8, 040 01 Kosice, Slovakia
| | - Michal Virag
- Eastern Slovak Institute of Cardiovascular Diseases and Faculty of Medicine, Pavol Jozef Safarik University, Kosice, Ondavska 8, 040 01 Kosice, Slovakia
| | - Ivan Kopolovets
- Eastern Slovak Institute of Cardiovascular Diseases and Faculty of Medicine, Pavol Jozef Safarik University, Kosice, Ondavska 8, 040 01 Kosice, Slovakia
| | - Miroslava Nemethova
- Institute of Neurobiology of Biomedical Research Center, Slovak Academy of Sciences, Soltesovej 4, 040 01 Kosice, Slovakia
| | - Rastislav Mucha
- Institute of Neurobiology of Biomedical Research Center, Slovak Academy of Sciences, Soltesovej 4, 040 01 Kosice, Slovakia.
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4
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Smalheiser NR. Mobile circular DNAs regulating memory and communication in CNS neurons. Front Mol Neurosci 2023; 16:1304667. [PMID: 38125007 PMCID: PMC10730651 DOI: 10.3389/fnmol.2023.1304667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 11/14/2023] [Indexed: 12/23/2023] Open
Abstract
Stimuli that stimulate neurons elicit transcription of immediate-early genes, a process which requires local sites of chromosomal DNA to form double-strand breaks (DSBs) generated by topoisomerase IIb within a few minutes, followed by repair within a few hours. Wakefulness, exploring a novel environment, and contextual fear conditioning also elicit turn-on of synaptic genes requiring DSBs and repair. It has been reported (in non-neuronal cells) that extrachromosomal circular DNA can form at DSBs as the sites are repaired. I propose that activated neurons may generate extrachromosomal circular DNAs during repair at DSB sites, thus creating long-lasting "markers" of that activity pattern which contain sequences from their sites of origin and which regulate long-term gene expression. Although the population of extrachromosomal DNAs is diverse and overall associated with pathology, a subclass of small circular DNAs ("microDNAs," ∼100-400 bases long), largely derives from unique genomic sequences and has attractive features to act as stable, mobile circular DNAs to regulate gene expression in a sequence-specific manner. Circular DNAs can be templates for the transcription of RNAs, particularly small inhibitory siRNAs, circular RNAs and other non-coding RNAs that interact with microRNAs. These may regulate translation and transcription of other genes involved in synaptic plasticity, learning and memory. Another possible fate for mobile DNAs is to be inserted stably into chromosomes after new DSB sites are generated in response to subsequent activation events. Thus, the insertions of mobile DNAs into activity-induced genes may tend to inactivate them and aid in homeostatic regulation to avoid over-excitation, as well as providing a "counter" for a neuron's activation history. Moreover, activated neurons release secretory exosomes that can be transferred to recipient cells to regulate their gene expression. Mobile DNAs may be packaged into exosomes, released in an activity-dependent manner, and transferred to recipient cells, where they may be templates for regulatory RNAs and possibly incorporated into chromosomes. Finally, aging and neurodegenerative diseases (including Alzheimer's disease) are also associated with an increase in DSBs in neurons. It will become important in the future to assess how pathology-associated DSBs may relate to activity-induced mobile DNAs, and whether the latter may potentially contribute to pathogenesis.
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Affiliation(s)
- Neil R. Smalheiser
- Department of Psychiatry, University of Illinois College of Medicine, Chicago, IL, United States
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5
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Wong GCN, Chow KHM. DNA Damage Response-Associated Cell Cycle Re-Entry and Neuronal Senescence in Brain Aging and Alzheimer's Disease. J Alzheimers Dis 2023; 94:S429-S451. [PMID: 35848025 PMCID: PMC10473156 DOI: 10.3233/jad-220203] [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] [Accepted: 06/07/2022] [Indexed: 11/15/2022]
Abstract
Chronological aging is by far the strongest risk factor for age-related dementia and Alzheimer's disease. Senescent cells accumulated in the aging and Alzheimer's disease brains are now recognized as the keys to describing such an association. Cellular senescence is a classic phenomenon characterized by stable cell arrest, which is thought to be applicable only to dividing cells. Emerging evidence indicates that fully differentiated post-mitotic neurons are also capable of becoming senescent, with roles in contributing to both brain aging and disease pathogenesis. The key question that arises is the identity of the upstream triggers and the molecular mechanisms that underly such changes. Here, we highlight the potential role of persistent DNA damage response as the major driver of senescent phenotypes and discuss the current evidence and molecular mechanisms that connect DNA repair infidelity, cell cycle re-entry and terminal fate decision in committing neuronal cell senescence.
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Affiliation(s)
- Genper Chi-Ngai Wong
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Hong Kong
| | - Kim Hei-Man Chow
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Hong Kong
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6
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Double-strand breaks induced by learning-like activity may increase risk of de novo mutations in schizophrenia. Asian J Psychiatr 2022; 78:103292. [PMID: 36252325 DOI: 10.1016/j.ajp.2022.103292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/03/2022] [Accepted: 10/06/2022] [Indexed: 11/20/2022]
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7
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Delint-Ramirez I, Konada L, Heady L, Rueda R, Jacome ASV, Marlin E, Marchioni C, Segev A, Kritskiy O, Yamakawa S, Reiter AH, Tsai LH, Madabhushi R. Calcineurin dephosphorylates topoisomerase IIβ and regulates the formation of neuronal-activity-induced DNA breaks. Mol Cell 2022; 82:3794-3809.e8. [PMID: 36206766 PMCID: PMC9990814 DOI: 10.1016/j.molcel.2022.09.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 07/27/2022] [Accepted: 09/09/2022] [Indexed: 11/13/2022]
Abstract
Neuronal activity induces topoisomerase IIβ (Top2B) to generate DNA double-strand breaks (DSBs) within the promoters of neuronal early response genes (ERGs) and facilitate their transcription, and yet, the mechanisms that control Top2B-mediated DSB formation are unknown. Here, we report that stimulus-dependent calcium influx through NMDA receptors activates the phosphatase calcineurin to dephosphorylate Top2B at residues S1509 and S1511, which stimulates its DNA cleavage activity and induces it to form DSBs. Exposing mice to a fear conditioning paradigm also triggers Top2B dephosphorylation at S1509 and S1511 in the hippocampus, indicating that calcineurin also regulates Top2B-mediated DSB formation following physiological neuronal activity. Furthermore, calcineurin-Top2B interactions following neuronal activity and sites that incur activity-induced DSBs are preferentially localized at the nuclear periphery in neurons. Together, these results reveal how radial gene positioning and the compartmentalization of activity-dependent signaling govern the position and timing of activity-induced DSBs and regulate gene expression patterns in neurons.
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Affiliation(s)
- Ilse Delint-Ramirez
- Departments of Psychiatry, Neuroscience, and Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Lahiri Konada
- Departments of Psychiatry, Neuroscience, and Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Lance Heady
- Departments of Psychiatry, Neuroscience, and Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Richard Rueda
- Departments of Psychiatry, Neuroscience, and Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | - Eric Marlin
- Departments of Psychiatry, Neuroscience, and Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Charlotte Marchioni
- Departments of Psychiatry, Neuroscience, and Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Amir Segev
- Departments of Psychiatry, Neuroscience, and Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Oleg Kritskiy
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Satoko Yamakawa
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | - Li-Huei Tsai
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA.
| | - Ram Madabhushi
- Departments of Psychiatry, Neuroscience, and Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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8
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Weber Boutros S, Unni VK, Raber J. An Adaptive Role for DNA Double-Strand Breaks in Hippocampus-Dependent Learning and Memory. Int J Mol Sci 2022; 23:8352. [PMID: 35955487 PMCID: PMC9368779 DOI: 10.3390/ijms23158352] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 12/10/2022] Open
Abstract
DNA double-strand breaks (DSBs), classified as the most harmful type of DNA damage based on the complexity of repair, lead to apoptosis or tumorigenesis. In aging, DNA damage increases and DNA repair decreases. This is exacerbated in disease, as post-mortem tissue from patients diagnosed with mild cognitive impairment (MCI) or Alzheimer's disease (AD) show increased DSBs. A novel role for DSBs in immediate early gene (IEG) expression, learning, and memory has been suggested. Inducing neuronal activity leads to increases in DSBs and upregulation of IEGs, while increasing DSBs and inhibiting DSB repair impairs long-term memory and alters IEG expression. Consistent with this pattern, mice carrying dominant AD mutations have increased baseline DSBs, and impaired DSB repair is observed. These data suggest an adaptive role for DSBs in the central nervous system and dysregulation of DSBs and/or repair might drive age-related cognitive decline (ACD), MCI, and AD. In this review, we discuss the adaptive role of DSBs in hippocampus-dependent learning, memory, and IEG expression. We summarize IEGs, the history of DSBs, and DSBs in synaptic plasticity, aging, and AD. DSBs likely have adaptive functions in the brain, and even subtle alterations in their formation and repair could alter IEGs, learning, and memory.
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Affiliation(s)
- Sydney Weber Boutros
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA;
| | - Vivek K. Unni
- Department of Neurology, Oregon Health & Science University, Portland, OR 97239, USA;
- Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, OR 97239, USA
- Oregon Health & Science University Parkinson Center, Portland, OR 97239, USA
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA;
- Department of Neurology, Oregon Health & Science University, Portland, OR 97239, USA;
- Department of Radiation Medicine, Oregon Health & Science University, Portland, OR 97239, USA
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR 97006, USA
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9
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Boutros SW, Kessler K, Unni VK, Raber J. Infusion of etoposide in the CA1 disrupts hippocampal immediate early gene expression and hippocampus-dependent learning. Sci Rep 2022; 12:12834. [PMID: 35896679 PMCID: PMC9329441 DOI: 10.1038/s41598-022-17052-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 07/20/2022] [Indexed: 11/21/2022] Open
Abstract
Tight regulation of immediate early gene (IEG) expression is important for synaptic plasticity, learning, and memory. Recent work has suggested that DNA double strand breaks (DSBs) may have an adaptive role in post-mitotic cells to induce IEG expression. Physiological activity in cultured neurons as well as behavioral training leads to increased DSBs and subsequent IEG expression. Additionally, infusion of etoposide-a common cancer treatment that induces DSBs-impairs trace fear memory. Here, we assessed the effects of hippocampal infusion of 60 ng of etoposide on IEG expression, learning, and memory in 3-4 month-old C57Bl/6J mice. Etoposide altered expression of the immediate early genes cFos and Arc in the hippocampus and impaired hippocampus-dependent contextual fear memory. These data add to the growing evidence that DSBs play an important role in IEG expression, learning, and memory, opening avenues for developing novel treatment strategies for memory-related disorders.
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Affiliation(s)
- Sydney Weber Boutros
- Department of Behavioral Neuroscience, OHSU, 3181 SW Sam Jackson Park Rd, Portland, OR, 97239, USA
| | - Kat Kessler
- Department of Behavioral Neuroscience, OHSU, 3181 SW Sam Jackson Park Rd, Portland, OR, 97239, USA
| | - Vivek K Unni
- Department of Neurology, OHSU, 3181 SW Sam Jackson Park Rd, Portland, OR, 97239, USA
- Jungers Center for Neurosciences Research, OHSU Parkinson Center, OHSU, 3181 SW Sam Jackson Park Rd, Portland, OR, 97239, USA
| | - Jacob Raber
- Department of Behavioral Neuroscience, OHSU, 3181 SW Sam Jackson Park Rd, Portland, OR, 97239, USA.
- Department of Neurology, OHSU, 3181 SW Sam Jackson Park Rd, Portland, OR, 97239, USA.
- Departments of Psychiatry and Radiation Medicine, OHSU, 3181 SW Sam Jackson Park Rd, Portland, OR, 97239, USA.
- Division of Neuroscience, ONPRC, 505 NW 185th Ave, Beaverton, OR, 97006, USA.
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10
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Konopka A, Atkin JD. The Role of DNA Damage in Neural Plasticity in Physiology and Neurodegeneration. Front Cell Neurosci 2022; 16:836885. [PMID: 35813507 PMCID: PMC9259845 DOI: 10.3389/fncel.2022.836885] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 05/09/2022] [Indexed: 12/15/2022] Open
Abstract
Damage to DNA is generally considered to be a harmful process associated with aging and aging-related disorders such as neurodegenerative diseases that involve the selective death of specific groups of neurons. However, recent studies have provided evidence that DNA damage and its subsequent repair are important processes in the physiology and normal function of neurons. Neurons are unique cells that form new neural connections throughout life by growth and re-organisation in response to various stimuli. This “plasticity” is essential for cognitive processes such as learning and memory as well as brain development, sensorial training, and recovery from brain lesions. Interestingly, recent evidence has suggested that the formation of double strand breaks (DSBs) in DNA, the most toxic form of damage, is a physiological process that modifies gene expression during normal brain activity. Together with subsequent DNA repair, this is thought to underlie neural plasticity and thus control neuronal function. Interestingly, neurodegenerative diseases such as Alzheimer’s disease, amyotrophic lateral sclerosis, frontotemporal dementia, and Huntington’s disease, manifest by a decline in cognitive functions, which are governed by plasticity. This suggests that DNA damage and DNA repair processes that normally function in neural plasticity may contribute to neurodegeneration. In this review, we summarize current understanding about the relationship between DNA damage and neural plasticity in physiological conditions, as well as in the pathophysiology of neurodegenerative diseases.
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Affiliation(s)
- Anna Konopka
- Centre for Motor Neuron Disease Research, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
- *Correspondence: Anna Konopka
| | - Julie D. Atkin
- Centre for Motor Neuron Disease Research, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
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11
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Enkephalin release from VIP interneurons in the hippocampal CA2/3a region mediates heterosynaptic plasticity and social memory. Mol Psychiatry 2022; 27:2879-2900. [PMID: 33990774 PMCID: PMC8590711 DOI: 10.1038/s41380-021-01124-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 03/23/2021] [Accepted: 04/13/2021] [Indexed: 12/22/2022]
Abstract
The hippocampus contains a diverse array of inhibitory interneurons that gate information flow through local cortico-hippocampal circuits to regulate memory storage. Although most studies of interneurons have focused on their role in fast synaptic inhibition mediated by GABA release, different classes of interneurons express unique sets of neuropeptides, many of which have been shown to exert powerful effects on neuronal function and memory when applied pharmacologically. However, relatively little is known about whether and how release of endogenous neuropeptides from inhibitory cells contributes to their behavioral role in regulating memory formation. Here we report that vasoactive intestinal peptide (VIP)-expressing interneurons participate in social memory storage by enhancing information transfer from hippocampal CA3 pyramidal neurons to CA2 pyramidal neurons. Notably, this action depends on release of the neuropeptide enkephalin from VIP neurons, causing long-term depression of feedforward inhibition onto CA2 pyramidal cells. Moreover, VIP neuron activity in the CA2 region is increased selectively during exploration of a novel conspecific. Our findings, thus, enhance our appreciation of how GABAergic neurons can regulate synaptic plasticity and mnemonic behavior by demonstrating that such actions can be mediated by release of a specific neuropeptide, rather than through classic fast inhibitory transmission.
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12
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du Plessis KC, Basu S, Rumbell TH, Lucas EK. Sex-Specific Neural Networks of Cued Threat Conditioning: A Pilot Study. Front Syst Neurosci 2022; 16:832484. [PMID: 35656357 PMCID: PMC9152023 DOI: 10.3389/fnsys.2022.832484] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 04/07/2022] [Indexed: 11/28/2022] Open
Abstract
Cued threat conditioning is the most common preclinical model for emotional memory, which is dysregulated in anxiety disorders and post-traumatic stress disorder. Though women are twice as likely as men to develop these disorders, current knowledge of threat conditioning networks was established by studies that excluded female subjects. For unbiased investigation of sex differences in these networks, we quantified the neural activity marker c-fos across 112 brain regions in adult male and female mice after cued threat conditioning compared to naïve controls. We found that trained females engaged prelimbic cortex, lateral amygdala, cortical amygdala, dorsal peduncular cortex, and subparafasicular nucleus more than, and subparaventricular zone less than, trained males. To explore how these sex differences in regional activity impact the global network, we generated interregional cross-correlations of c-fos expression to identify regions that were co-active during conditioning and performed hub analyses to identify regional control centers within each neural network. These exploratory graph theory-derived analyses revealed sex differences in the functional coordination of the threat conditioning network as well as distinct hub regions between trained males and females. Hub identification across multiple networks constructed by sequentially pruning the least reliable connections revealed globus pallidus and ventral lateral septum as the most robust hubs for trained males and females, respectively. While low sample size and lack of non-associative controls are major limitations, these findings provide preliminary evidence of sex differences in the individual circuit components and broader global networks of threat conditioning that may confer female vulnerability to fear-based psychiatric disease.
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Affiliation(s)
- Kamryn C. du Plessis
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Sreetama Basu
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
- Department of Neurosciences, Cleveland Clinic, Cleveland, OH, United States
| | - Timothy H. Rumbell
- IBM Thomas J. Watson Research Center, Yorktown Heights, NY, United States
| | - Elizabeth K. Lucas
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
- *Correspondence: Elizabeth K. Lucas,
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13
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Chandramouly G. Gadd45 in DNA Demethylation and DNA Repair. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1360:55-67. [PMID: 35505162 DOI: 10.1007/978-3-030-94804-7_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Growth arrest and DNA damage 45 (Gadd45) family genes, Gadd45A, Gadd45B, and GADD45 G are implicated as stress sensors that are rapidly induced upon genotoxic/physiological stress. They are involved in regulation of various cellular functions such as DNA repair, senescence, and cell cycle control. Gadd45 family of genes serve as tumor suppressors in response to different stimuli and defects in Gadd45 pathway can give rise to oncogenesis. More recently, Gadd45 has been shown to promote gene activation by demethylation and this function is important for transcriptional regulation and differentiation during development. Gadd45 serves as an adaptor for DNA repair factors to promote removal of 5-methylcytosine from DNA at gene specific loci. Therefore, Gadd45 serves as a powerful link between DNA repair and epigenetic gene regulation.
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Affiliation(s)
- Gurushankar Chandramouly
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA.
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14
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Genome Integrity and Neurological Disease. Int J Mol Sci 2022; 23:ijms23084142. [PMID: 35456958 PMCID: PMC9025063 DOI: 10.3390/ijms23084142] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/02/2022] [Accepted: 04/05/2022] [Indexed: 02/06/2023] Open
Abstract
Neurological complications directly impact the lives of hundreds of millions of people worldwide. While the precise molecular mechanisms that underlie neuronal cell loss remain under debate, evidence indicates that the accumulation of genomic DNA damage and consequent cellular responses can promote apoptosis and neurodegenerative disease. This idea is supported by the fact that individuals who harbor pathogenic mutations in DNA damage response genes experience profound neuropathological manifestations. The review article here provides a general overview of the nervous system, the threats to DNA stability, and the mechanisms that protect genomic integrity while highlighting the connections of DNA repair defects to neurological disease. The information presented should serve as a prelude to the Special Issue “Genome Stability and Neurological Disease”, where experts discuss the role of DNA repair in preserving central nervous system function in greater depth.
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15
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Brito DV, Kupke J, Gulmez Karaca K, Oliveira AM. Regulation of neuronal plasticity by the DNA repair associated Gadd45 proteins. CURRENT RESEARCH IN NEUROBIOLOGY 2022; 3:100031. [PMID: 36685757 PMCID: PMC9846468 DOI: 10.1016/j.crneur.2022.100031] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 01/17/2022] [Accepted: 02/07/2022] [Indexed: 01/25/2023] Open
Abstract
Neurons respond rapidly to extracellular stimuli by activating signaling pathways that modulate the function of already synthetized proteins. Alternatively, signal transduction to the cell nucleus induces de novo synthesis of proteins required for long-lasting adaptations. These complementary strategies are necessary for neuronal plasticity processes that underlie, among other functions, the formation of memories. Nonetheless, it is still not fully understood how the coupling between different stimuli and the activity of constitutively and/or de novo expressed proteins gate neuronal plasticity. Here, we discuss the molecular functions of the Growth Arrest and DNA Damage 45 (Gadd45) family of proteins in neuronal adaptation. We highlight recent findings that indicate that Gadd45 family members regulate this function through multiple cellular processes (e.g., DNA demethylation, gene expression, RNA stability, MAPK signaling). We then summarize the regulation of Gadd45 expression in neurons and put forward the hypothesis that the constitutive and neuronal activity-induced pools of Gadd45 proteins have distinct and complementary roles in modulating neuronal plasticity. Therefore, we propose that Gadd45 proteins are essential for brain function and their dysfunction might underlie pathophysiological conditions such as neuropsychiatric disorders.
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Affiliation(s)
- David V.C. Brito
- Institute of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, INF 366, 69120, Heidelberg, Germany,Algarve Biomedical Center Research Institute (ABC-RI), University of Algarve, 8005-139, Faro, Portugal
| | - Janina Kupke
- Institute of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, INF 366, 69120, Heidelberg, Germany
| | - Kubra Gulmez Karaca
- Institute of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, INF 366, 69120, Heidelberg, Germany,Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center Kapittelweg 29, 6525, EN Nijmegen, the Netherlands
| | - Ana M.M. Oliveira
- Institute of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, INF 366, 69120, Heidelberg, Germany,Corresponding author. Institute of Neurobiology, Interdisciplinary Center for Neurosciences (IZN) Heidelberg University, Im Neuenheimer Feld 366, 69120, Heidelberg, Germany.
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16
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Boutros SW, Krenik D, Holden S, Unni VK, Raber J. Common cancer treatments targeting DNA double strand breaks affect long-term memory and relate to immediate early gene expression in a sex-dependent manner. Oncotarget 2022; 13:198-213. [PMID: 35106123 PMCID: PMC8794536 DOI: 10.18632/oncotarget.28180] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 01/10/2022] [Indexed: 11/25/2022] Open
Abstract
DNA double strand breaks (DSBs) have been highly studied in the context of cancers, as DSBs can lead to apoptosis or tumorigenesis. Several pharmaceuticals are widely used to target DSBs during cancer therapy. Amifostine (WR-2721) and etoposide are two commonly used drugs: amifostine reduces DSBs, whereas etoposide increases DSBs. Recently, a novel role for DSBs in immediate early gene expression, learning, and memory has been suggested. Neither amifostine nor etoposide have been assessed for their effects on learning and memory without confounding factors. Moreover, sex-dependent effects of these drugs have not been reported. We administered amifostine or etoposide to 3-4-month-old male and female C57Bl/6J mice before or after training in fear conditioning and assessed learning, memory, and immediate early genes. We observed sex-dependent baseline and drug-induced differences, with females expressing higher cFos and FosB levels than males. These were affected by both amifostine and etoposide. Post-training injections of amifostine affected long-term contextual fear memory; etoposide affected contextual and cued fear memory. These data support the hypothesis that DSBs contribute to learning and memory, and that these could play a part in cognitive side effects during common treatment regimens. The sex-dependent effects also highlight an important factor when considering treatment plans.
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Affiliation(s)
- Sydney Weber Boutros
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239, USA
| | - Destine Krenik
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239, USA
| | - Sarah Holden
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239, USA
| | - Vivek K. Unni
- Department of Neurology, Oregon Health and Science University, Portland, OR 97239, USA
- Jungers Center for Neurosciences Research, Oregon Health and Science University, Portland, OR 97239, USA
- OHSU Parkinson Center, Oregon Health and Science University, Portland, OR 97239, USA
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239, USA
- Department of Neurology, Oregon Health and Science University, Portland, OR 97239, USA
- Department of Psychiatry, Oregon Health and Science University, Portland, OR 97239, USA
- Department of Radiation Medicine, Oregon Health and Science University, Portland, OR 97239, USA
- Division of Neuroscience, The Oregon National Primate Research Center, Oregon Health and Science University, Portland, OR 97239, USA
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17
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Yotsuya Y, Hasegawa Y. Nacre extract from pearl oyster attenuates amyloid beta-induced memory impairment. J Nat Med 2022; 76:419-434. [PMID: 35044595 DOI: 10.1007/s11418-021-01598-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 12/20/2021] [Indexed: 10/19/2022]
Abstract
Shells are composed of two types of calcium carbonate polymorphs-the prismatic layer and the nacreous layer. Pearls, composed of the nacreous layer, have been used in Chinese medicine since ancient times. We have previously shown that extracts from the nacreous layer improves scopolamine-induced memory impairment. However, whether pearl ameliorates cognitive disorders induced by amyloid-β 1-40 (Aβ1-40) has not been elucidated. In this study, we investigated whether nacre extract improves memory impairment induced by intracerebroventricular injection of Aβ1-40. Administration of nacre extract led to recovery from Aβ1-40-induced impairments in object recognition, short-term memory, and spatial memory. Nacre extract reversed the increase in lipid peroxidation caused by Aβ1-40 in the cerebral cortex by increasing the expression of catalase and superoxide dismutase. In addition, nacre extract recovered the expression and phosphorylation of cyclic AMP response element-binding protein (CREB), which decreased with Aβ1-40 treatment, and increased the expression of brain-derived neurotrophic factor and neuropeptide Y, which are regulated by CREB. Nacre extract also suppressed acetylcholine esterase activity and Aβ1-40-induced tau phosphorylation. Histochemical analysis of the hippocampus region showed that the nacre extract protected against Aβ1-40-induced neuronal loss in the hippocampus. These results suggest that nacre extract protects against Aβ1-40-induced neuronal cell death by suppressing oxidative stress and increasing the expression and phosphorylation of CREB.
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Affiliation(s)
- Yamato Yotsuya
- College of Environmental Technology, Muroran Institute of Technology, 27-1 Mizumoto, Muroran, 050-8585, Japan
| | - Yasushi Hasegawa
- College of Environmental Technology, Muroran Institute of Technology, 27-1 Mizumoto, Muroran, 050-8585, Japan.
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18
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Feng Y, Wang Z, Wei W, Zhang T, Li Z, Chen J, Liu K. Gadd45α is involved in regulating activity-dependent and exon-specific BDNF expression in postmitotic cortical neurons. Neuroreport 2021; 32:1147-1152. [PMID: 34334778 DOI: 10.1097/wnr.0000000000001705] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVE This study aimed to explore the epigenetic regulation of activity-dependent and exon-specific brain-derived neurotrophic factor (BDNF) expression under KCl depolarization in primary cortical neurons. METHODS We investigated BDNF exon I, exon IV and the growth arrest and DNA damage-inducible protein 45 alpha (Gadd45α) transcription levels under KCl-induced neuronal activation in postmitotic neurons. Gadd45α occupancy at BDNF I and IV promoter was measured by chromatin immunoprecipitation (ChIP) followed by quantitative PCR; DNA methylation level was checked by methylated DNA immunoprecipitation (MeDIP) followed by qPCR. In addition, lentiviral shRNA targeting Gadd45α was used to knockdown Gadd45α expression. RESULTS BDNF exon I and IV mRNA expressions were both highly induced by KCl depolarization. However, ChIP analysis demonstrated a significantly increased Gadd45α occupancy only at the BDNF P1 promotor, but not P4, which is associated with reducing DNA methylation within BDNF P1 promoter. Furthermore, after the lentiviral-mediated knockdown of Gadd45α, the increased Gadd45α occupancy at the BDNF P1 was inhibited, which was accompanying the complete blocking of the demethylation effect at P1. Nonetheless, the induction of BDNF exon I mRNA by KCl was only partially prevented by Gadd45α shRNA, indicting other mechanisms involved in regulating BDNF exon I expression. CONCLUSIONS DNA demethylation mediated by Gadd45α protein involves promoting the regulation of activity-dependent BDNF exon I expression in neurons.
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Affiliation(s)
- Yu Feng
- Department of Neurosurgery, Zhongnan Hospital of Wuhan University, Wuhan, China
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19
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Ionescu-Tucker A, Cotman CW. Emerging roles of oxidative stress in brain aging and Alzheimer's disease. Neurobiol Aging 2021; 107:86-95. [PMID: 34416493 DOI: 10.1016/j.neurobiolaging.2021.07.014] [Citation(s) in RCA: 225] [Impact Index Per Article: 75.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/09/2021] [Accepted: 07/17/2021] [Indexed: 12/30/2022]
Abstract
Reactive oxygen species (ROS) are metabolic byproducts that are necessary for physiological function but can be toxic at high levels. Levels of these oxidative stressors increase gradually throughout the lifespan, impairing mitochondrial function and damaging all parts of the body, particularly the central nervous system. Emerging evidence suggests that accumulated oxidative stress may be one of the key mechanisms causing cognitive aging and neurodegenerative diseases such as Alzheimer's disease (AD). Here, we synthesize the current literature on the effect of neuronal oxidative stress on mitochondrial dysfunction, DNA damage and epigenetic changes related to cognitive aging and AD. We further describe how oxidative stress therapeutics such as antioxidants, caloric restriction and physical activity can reduce oxidation and prevent cognitive decline in brain aging and AD. Of the currently available therapeutics, we propose that long term physical activity is the most promising avenue for improving cognitive health by reducing ROS while promoting the low levels required for optimal function.
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Affiliation(s)
- Andra Ionescu-Tucker
- Institute for Memory Impairments and Neurological Disorders, Department of Neurobiology and Behavior, University of California at Irvine, Irvine, California.
| | - Carl W Cotman
- Institute for Memory Impairments and Neurological Disorders, Department of Neurobiology and Behavior, University of California at Irvine, Irvine, California.
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20
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Martin K, Musaus M, Navabpour S, Gustin A, Ray WK, Helm RF, Jarome TJ. Females, but not males, require protein degradation in the hippocampus for contextual fear memory formation. ACTA ACUST UNITED AC 2021; 28:248-253. [PMID: 34266989 PMCID: PMC8284313 DOI: 10.1101/lm.053429.121] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/07/2021] [Indexed: 11/30/2022]
Abstract
Strong evidence supports a role for protein degradation in fear memory formation. However, these data have been largely done in only male animals. Here, we found that following contextual fear conditioning, females, but not males, had increased levels of proteasome activity and K48 polyubiquitin protein targeting in the dorsal hippocampus, the latter of which occurred at chaperones or RNA processing proteins. In vivo CRISPR–dCas9-mediated repression of protein degradation in the dorsal hippocampus impaired contextual fear memory in females, but not males. These results suggest a sex-specific role for protein degradation in the hippocampus during the consolidation of a contextual fear memory.
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Affiliation(s)
- Kiley Martin
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
| | - Madeline Musaus
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
| | - Shaghayegh Navabpour
- Fralin Biomedical Research Institute, Department of Translational Biology, Medicine, and Health, Virginia Polytechnic Institute and State University, Roanoke, Virginia 24016, USA
| | - Aspen Gustin
- Department of Animal and Poultry Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
| | - W Keith Ray
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
| | - Richard F Helm
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
| | - Timothy J Jarome
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA.,Fralin Biomedical Research Institute, Department of Translational Biology, Medicine, and Health, Virginia Polytechnic Institute and State University, Roanoke, Virginia 24016, USA.,Department of Animal and Poultry Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
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21
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Stott RT, Kritsky O, Tsai LH. Profiling DNA break sites and transcriptional changes in response to contextual fear learning. PLoS One 2021; 16:e0249691. [PMID: 34197463 PMCID: PMC8248687 DOI: 10.1371/journal.pone.0249691] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 05/27/2021] [Indexed: 12/12/2022] Open
Abstract
Neuronal activity generates DNA double-strand breaks (DSBs) at specific loci in vitro and this facilitates the rapid transcriptional induction of early response genes (ERGs). Physiological neuronal activity, including exposure of mice to learning behaviors, also cause the formation of DSBs, yet the distribution of these breaks and their relation to brain function remains unclear. Here, following contextual fear conditioning (CFC) in mice, we profiled the locations of DSBs genome-wide in the medial prefrontal cortex and hippocampus using γH2AX ChIP-Seq. Remarkably, we found that DSB formation is widespread in the brain compared to cultured primary neurons and they are predominately involved in synaptic processes. We observed increased DNA breaks at genes induced by CFC in neuronal and non-neuronal nuclei. Activity-regulated and proteostasis-related transcription factors appear to govern some of these gene expression changes across cell types. Finally, we find that glia but not neurons have a robust transcriptional response to glucocorticoids, and many of these genes are sites of DSBs. Our results indicate that learning behaviors cause widespread DSB formation in the brain that are associated with experience-driven transcriptional changes across both neuronal and glial cells.
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Affiliation(s)
- Ryan T. Stott
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, United States of America
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Oleg Kritsky
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, United States of America
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Li-Huei Tsai
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, United States of America
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States of America
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22
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Dick A, Chen A. The role of TET proteins in stress-induced neuroepigenetic and behavioural adaptations. Neurobiol Stress 2021; 15:100352. [PMID: 34189192 PMCID: PMC8220100 DOI: 10.1016/j.ynstr.2021.100352] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 05/21/2021] [Accepted: 06/05/2021] [Indexed: 12/27/2022] Open
Abstract
Over the past decade, critical, non-redundant roles of the ten-eleven translocation (TET) family of dioxygenase enzymes have been identified in the brain during developmental and postnatal stages. Specifically, TET-mediated active demethylation, involving the iterative oxidation of 5-methylcytosine to 5-hydroxymethylcytosine and subsequent oxidative derivatives, is dynamically regulated in response to environmental stimuli such as neuronal activity, learning and memory processes, and stressor exposure. Such changes may therefore perpetuate stable and dynamic transcriptional patterns within neuronal populations required for neuroplasticity and behavioural adaptation. In this review, we will highlight recent evidence supporting a role of TET protein function and active demethylation in stress-induced neuroepigenetic and behavioural adaptations. We further explore potential mechanisms by which TET proteins may mediate both the basal and pathological embedding of stressful life experiences within the brain of relevance to stress-related psychiatric disorders.
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Affiliation(s)
- Alec Dick
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
- Corresponding author.
| | - Alon Chen
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
- The Ruhman Family Laboratory for Research on the Neurobiology of Stress, Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
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23
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Gold AR, Glanzman DL. The central importance of nuclear mechanisms in the storage of memory. Biochem Biophys Res Commun 2021; 564:103-113. [PMID: 34020774 DOI: 10.1016/j.bbrc.2021.04.125] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 04/28/2021] [Accepted: 04/28/2021] [Indexed: 12/14/2022]
Abstract
The neurobiological nature of the memory trace (engram) remains controversial. The most widely accepted hypothesis at present is that long-term memory is stored as stable, learning-induced changes in synaptic connections. This hypothesis, the synaptic plasticity hypothesis of memory, is supported by extensive experimental data gathered from over 50 years of research. Nonetheless, there are important mnemonic phenomena that the synaptic plasticity hypothesis cannot, or cannot readily, account for. Furthermore, recent work indicates that epigenetic and genomic mechanisms play heretofore underappreciated roles in memory. Here, we critically assess the evidence that supports the synaptic plasticity hypothesis and discuss alternative non-synaptic, nuclear mechanisms of memory storage, including DNA methylation and retrotransposition. We argue that long-term encoding of memory is mediated by nuclear processes; synaptic plasticity, by contrast, represents a means of relatively temporary memory storage. In addition, we propose that memories are evaluated for their mnemonic significance during an initial period of synaptic storage; if assessed as sufficiently important, the memories then undergo nuclear encoding.
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Affiliation(s)
- Adam R Gold
- Behavioral Neuroscience Program, Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
| | - David L Glanzman
- Department of Integrative Biology & Physiology, UCLA College, University of California, Los Angeles, Los Angeles, CA, 90095, USA; Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA, 90095, USA; Integrative Center for Learning and Memory, Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
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24
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Dick AL, Zhao Q, Crossin R, Baker‐Andresen D, Li X, Edson J, Roeh S, Marshall V, Bredy TW, Lawrence AJ, Duncan JR. Adolescent chronic intermittent toluene inhalation dynamically regulates the transcriptome and neuronal methylome within the rat medial prefrontal cortex. Addict Biol 2021; 26:e12937. [PMID: 32638524 DOI: 10.1111/adb.12937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/25/2020] [Accepted: 06/24/2020] [Indexed: 12/14/2022]
Abstract
Inhalants containing the volatile solvent toluene are misused to induce euphoria or intoxication. Inhalant abuse is most common during adolescence and can result in cognitive impairments during an important maturational period. Despite evidence suggesting that epigenetic modifications may underpin the cognitive effects of inhalants, no studies to date have thoroughly investigated toluene-induced regulation of the transcriptome or discrete epigenetic modifications within the brain. To address this, we investigated effects of adolescent chronic intermittent toluene (CIT) inhalation on gene expression and DNA methylation profiles within the rat medial prefrontal cortex (mPFC), which undergoes maturation throughout adolescence and has been implicated in toluene-induced cognitive deficits. Employing both RNA-seq and genome-wide Methyl CpG Binding Domain (MBD) Ultra-seq analysis, we demonstrate that adolescent CIT inhalation (10 000 ppm for 1 h/day, 3 days/week for 4 weeks) induces both transient and persistent changes to the transcriptome and DNA methylome within the rat mPFC for at least 2 weeks following toluene exposure. We demonstrate for the first time that adolescent CIT exposure results in dynamic regulation of the mPFC transcriptome likely relating to acute inflammatory responses and persistent deficits in synaptic plasticity. These adaptations may contribute to the cognitive deficits associated with chronic toluene exposure and provide novel molecular targets for preventing long-term neurophysiological abnormalities following chronic toluene inhalation.
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Affiliation(s)
- Alec L.W. Dick
- Florey Institute of Neuroscience and Mental Health University of Melbourne Melbourne VIC Australia
- Department of Stress Neurobiology and Neurogenetics Max Planck Institute of Psychiatry Munich Germany
| | - Qiongyi Zhao
- Queensland Brain Institute University of Queensland Brisbane QLD Australia
| | - Rose Crossin
- Florey Institute of Neuroscience and Mental Health University of Melbourne Melbourne VIC Australia
| | | | - Xiang Li
- Queensland Brain Institute University of Queensland Brisbane QLD Australia
| | - Janette Edson
- Queensland Brain Institute University of Queensland Brisbane QLD Australia
| | - Simone Roeh
- Department of Translational Research in Psychiatry Max Planck Institute of Psychiatry Munich Germany
| | - Victoria Marshall
- Queensland Brain Institute University of Queensland Brisbane QLD Australia
| | - Timothy W. Bredy
- Queensland Brain Institute University of Queensland Brisbane QLD Australia
| | - Andrew J. Lawrence
- Florey Institute of Neuroscience and Mental Health University of Melbourne Melbourne VIC Australia
| | - Jhodie R. Duncan
- Florey Institute of Neuroscience and Mental Health University of Melbourne Melbourne VIC Australia
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25
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Canever L, Varela R, Mastella GA, Damázio LS, Valvassori SS, Quevedo JL, Zugno AI. Effects of maternal folic acid supplementation on nuclear methyltransferase activity of adult rats subjected to an animal model of schizophrenia. Int J Dev Neurosci 2021; 81:461-467. [PMID: 33786893 DOI: 10.1002/jdn.10109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 03/23/2021] [Accepted: 03/25/2021] [Indexed: 11/09/2022] Open
Abstract
INTRODUCTION Schizophrenia is considered one of the most disabling and severe human diseases worldwide. The etiology of schizophrenia is thought to be multifactorial and evidence suggests that DNA methylation can play an important role in underlying pivotal neurobiological alterations of this disorder. Some studies have demonstrated the effects of dietary supplementation as an alternative approach to the prevention of schizophrenia, including folic acid. However, no study has ever investigated the role of such supplementation in altering the DNA methylation system in the context of schizophrenia. OBJECTIVES The present study aims to investigate the effects of maternal folic acid supplementation at different doses on nuclear methyltransferase activity of adult rat offspring subjected to an animal model schizophrenia induced by ketamine. METHODS Adult female Wistar rats, (60 days old) received folic acid-deficient diet, control diet, or control diet plus folic acid supplementation (at 5, 10, or 50 mg/kg) during pregnancy and lactation. After reaching adulthood (60 days), the male offspring of these dams were subjected to the animal model of schizophrenia induced by 7 days of ketamine intraperitoneal injection (25 mg/kg). After the 7-day protocol, the activity of nuclear methyltransferase was evaluated in the brains of the offspring. RESULTS Maternal folic acid supplementation at 50 mg/kg increased methyltransferase activity in the frontal cortex, while 10 mg/kg increased methyltransferase activity in the hippocampus. In the striatum of offspring treated with ketamine, maternal deficient diet, control diet, and folic acid supplementation at 5 mg/kg decreased methyltransferase activity compared to the control group. The folic acid supplementation at 10 and 50 mg/kg reversed this ketamine effect. CONCLUSIONS Maternal FA deficiency could be related to schizophrenia pathophysiology, while FA supplementation could present a protective effect since it demonstrated persistent effects in epigenetic parameters in adult offspring.
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Affiliation(s)
- Lara Canever
- Translational Psychiatry Laboratory, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - Roger Varela
- Translational Psychiatry Laboratory, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - Gustavo A Mastella
- Translational Psychiatry Laboratory, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - Louyse S Damázio
- Translational Psychiatry Laboratory, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - Samira S Valvassori
- Translational Psychiatry Laboratory, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - João L Quevedo
- Translational Psychiatry Laboratory, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil.,Translational Psychiatry Program, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA.,Center of Excellence on Mood Disorders, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA.,Neuroscience Graduate Program, The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Alexandra I Zugno
- Translational Psychiatry Laboratory, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
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Sanchez-Alavez M, Bortell N, Basova L, Samad F, Marcondes MCG. Macrophages and brown adipocytes cross-communicate to modulate a thermogenic program following methamphetamine exposure. Int J Hyperthermia 2020; 37:1368-1382. [PMID: 33307890 PMCID: PMC9472558 DOI: 10.1080/02656736.2020.1849822] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Hyperthermia is a potentially lethal side-effect of Methamphetamine (Meth), a stimulant drug. Activation of non-shivering thermogenesis in brown adipose tissue (BAT) is partly responsible for Meth-induced rise in temperature, with contributing sympathetic neurotransmitters, such as norepinephrine (NE), and reactive oxygen species (ROS). However, the mechanisms controlling the development of a molecular thermogenic program in brown adipocytes (BA) following Meth are unknown. We hypothesize that Meth and NE affect BAT cells, BA and macrophages, to modify their physiology and interactions, with consequences to thermogenic genes. We also hypothesize that ROS play a critical role in signaling transcription of thermogenic genes and their regulatory components. Using primary BA and macrophage cultures, we measured Meth and NE interference with physiological and phenotypic measures that are relevant to thermogenesis in BAT. Meth caused both BA and macrophages to decrease mitochondrial maximal capacity and increase ROS. In BA, the thermogenic genes UCP1, PPARγ, PGC1α and GADD45γ were transcriptionally increased by Meth in a ROS-dependent manner. In macrophages, Meth increased oxidative stress response and caused a predominance of M2 subset markers. BA transcriptional changes in response to Meth and NE were significantly controlled by macrophages. The results suggest that BA and macrophages respond to Meth and NE, with effects on mitochondrial functions and transcription of genes involved in thermogenesis. ROS-dependent signals in BA and cellular interactions between BA and macrophages synergize to regulate the BAT environment and control critical pathways leading to Meth-hyperthermia.
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Affiliation(s)
- Manuel Sanchez-Alavez
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA.,Facultad de Medicina y Psicología, Universidad Autónoma de Baja California, Tijuana, México
| | - Nikki Bortell
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA
| | - Liana Basova
- San Diego Biomedical Research Institute, San Diego, CA, USA
| | - Fahumiya Samad
- San Diego Biomedical Research Institute, San Diego, CA, USA
| | - Maria Cecilia Garibaldi Marcondes
- Facultad de Medicina y Psicología, Universidad Autónoma de Baja California, Tijuana, México.,San Diego Biomedical Research Institute, San Diego, CA, USA
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Navabpour S, Rogers J, McFadden T, Jarome TJ. DNA Double-Strand Breaks Are a Critical Regulator of Fear Memory Reconsolidation. Int J Mol Sci 2020; 21:ijms21238995. [PMID: 33256213 PMCID: PMC7730899 DOI: 10.3390/ijms21238995] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 11/23/2020] [Accepted: 11/23/2020] [Indexed: 11/16/2022] Open
Abstract
Numerous studies have shown that following retrieval, a previously consolidated memory requires increased transcriptional regulation in order to be reconsolidated. Previously, it was reported that histone H3 lysine-4 trimethylation (H3K4me3), a marker of active transcription, is increased in the hippocampus after the retrieval of contextual fear memory. However, it is currently unknown how this epigenetic mark is regulated during the reconsolidation process. Furthermore, though recent evidence suggests that neuronal activity triggers DNA double-strand breaks (DSBs) in some early-response genes, it is currently unknown if DSBs contribute to the reconsolidation of a memory following retrieval. Here, using chromatin immunoprecipitation (ChIP) analyses, we report a significant overlap between DSBs and H3K4me3 in area CA1 of the hippocampus during the reconsolidation process. We found an increase in phosphorylation of histone H2A.X at serine 139 (H2A.XpS139), a marker of DSB, in the Npas4, but not c-fos, promoter region 5 min after retrieval, which correlated with increased H3K4me3 levels, suggesting that the two epigenetic marks may work in concert during the reconsolidation process. Consistent with this, in vivo siRNA-mediated knockdown of topoisomerase II β, the enzyme responsible for DSB, prior to retrieval, reduced Npas4 promoter-specific H2A.XpS139 and H3K4me3 levels and impaired long-term memory, indicating an indispensable role of DSBs in the memory reconsolidation process. Collectively, our data propose a novel mechanism for memory reconsolidation through increases in epigenetic-mediated transcriptional control via DNA double-strand breaks.
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Affiliation(s)
- Shaghayegh Navabpour
- Fralin Biomedical Research Institute, Translational Biology, Medicine & Health, Virginia Polytechnic Institute and State University, Roanoke, VA 24016, USA;
| | - Jessie Rogers
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA;
| | - Taylor McFadden
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA;
| | - Timothy J. Jarome
- Fralin Biomedical Research Institute, Translational Biology, Medicine & Health, Virginia Polytechnic Institute and State University, Roanoke, VA 24016, USA;
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA;
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
- Correspondence: ; Tel.: +1-540-231-3520
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28
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Hogan MK, Hamilton GF, Horner PJ. Neural Stimulation and Molecular Mechanisms of Plasticity and Regeneration: A Review. Front Cell Neurosci 2020; 14:271. [PMID: 33173465 PMCID: PMC7591397 DOI: 10.3389/fncel.2020.00271] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 07/31/2020] [Indexed: 12/23/2022] Open
Abstract
Neural stimulation modulates the depolarization of neurons, thereby triggering activity-associated mechanisms of neuronal plasticity. Activity-associated mechanisms in turn play a major role in post-mitotic structure and function of adult neurons. Our understanding of the interactions between neuronal behavior, patterns of neural activity, and the surrounding environment is evolving at a rapid pace. Brain derived neurotrophic factor is a critical mediator of activity-associated plasticity, while multiple immediate early genes mediate plasticity of neurons following bouts of neural activity. New research has uncovered genetic mechanisms that govern the expression of DNA following changes in neural activity patterns, including RNAPII pause-release and activity-associated double stranded breaks. Discovery of novel mechanisms governing activity-associated plasticity of neurons hints at a layered and complex molecular control of neuronal response to depolarization. Importantly, patterns of depolarization in neurons are shown to be important mediators of genetic expression patterns and molecular responses. More research is needed to fully uncover the molecular response of different types of neurons-to-activity patterns; however, known responses might be leveraged to facilitate recovery after neural damage. Physical rehabilitation through passive or active exercise modulates neurotrophic factor expression in the brain and spinal cord and can initiate cortical plasticity commensurate with functional recovery. Rehabilitation likely relies on activity-associated mechanisms; however, it may be limited in its application. Electrical and magnetic stimulation direct specific activity patterns not accessible through passive or active exercise and work synergistically to improve standing, walking, and forelimb use after injury. Here, we review emerging concepts in the molecular mechanisms of activity-derived plasticity in order to highlight opportunities that could add value to therapeutic protocols for promoting recovery of function after trauma, disease, or age-related functional decline.
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Affiliation(s)
- Matthew K Hogan
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston Methodist Hospital, Houston, TX, United States
| | - Gillian F Hamilton
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston Methodist Hospital, Houston, TX, United States
| | - Philip J Horner
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston Methodist Hospital, Houston, TX, United States
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29
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Brito DVC, Gulmez Karaca K, Kupke J, Mudlaff F, Zeuch B, Gomes R, Lopes LV, Oliveira AMM. Modeling human age-associated increase in Gadd45γ expression leads to spatial recognition memory impairments in young adult mice. Neurobiol Aging 2020; 94:281-286. [PMID: 32711258 DOI: 10.1016/j.neurobiolaging.2020.06.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 05/22/2020] [Accepted: 06/27/2020] [Indexed: 12/18/2022]
Abstract
Aging is associated with the progressive decay of cognitive function. Hippocampus-dependent processes, such as the formation of spatial memory, are particularly vulnerable to aging. Currently, the molecular mechanisms responsible for age-dependent cognitive decline are largely unknown. Here, we investigated the expression and function of the growth arrest DNA damage gamma (Gadd45γ) during aging and cognition. We report that Gadd45γ expression is increased in the hippocampus of aged humans and that Gadd45γ overexpression in the young adult mouse hippocampus compromises cognition. Moreover, Gadd45γ overexpression in hippocampal neurons disrupted cAMP response element-binding protein signaling and the expression of well-established activity-regulated genes. This work shows that Gadd45γ expression is tightly controlled in the hippocampus and its disruption may be a mechanism contributing to age-related cognitive impairments observed in humans.
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Affiliation(s)
- David V C Brito
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Heidelberg, Germany
| | - Kubra Gulmez Karaca
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Heidelberg, Germany; Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Janina Kupke
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Heidelberg, Germany
| | - Franziska Mudlaff
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Heidelberg, Germany
| | - Benjamin Zeuch
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Heidelberg, Germany; Directors' Research, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Rui Gomes
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina de Lisboa, Universidade de Lisboa, Lisbon, Portugal
| | - Luísa V Lopes
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina de Lisboa, Universidade de Lisboa, Lisbon, Portugal
| | - Ana M M Oliveira
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Heidelberg, Germany.
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30
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Poon CH, Tse LSR, Lim LW. DNA methylation in the pathology of Alzheimer's disease: from gene to cognition. Ann N Y Acad Sci 2020; 1475:15-33. [PMID: 32491215 DOI: 10.1111/nyas.14373] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/16/2020] [Accepted: 04/24/2020] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is a debilitating disorder that manifests with amyloid beta plaque deposition, neurofibrillary tangles, neuronal loss, and severe cognitive impairment. Although much effort has been made to decipher the pathogenesis of this disease, the mechanisms causing these detrimental outcomes remain obscure. Over the past few decades, neuroepigenetics has emerged as an important field that, among other things, explores how reversible modifications can change gene expression to control behavior and cognitive abilities. Among epigenetic modifications, DNA methylation requires further elucidation for the conflicting observations from AD research and its pivotal role in learning and memory. In this review, we focus on the essential components of DNA methylation, the effects of aberrant methylation on gene expressions in the amyloidogenic pathway and neurochemical processes, as well as memory epigenetics in Alzheimer's disease.
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Affiliation(s)
- Chi Him Poon
- Neuromodulation Laboratory, Li Ka Shing Faculty of Medicine, School of Biomedical Sciences, the University of Hong Kong, Hong Kong, P. R. China
| | - Long Sum Rachel Tse
- Neuromodulation Laboratory, Li Ka Shing Faculty of Medicine, School of Biomedical Sciences, the University of Hong Kong, Hong Kong, P. R. China
| | - Lee Wei Lim
- Neuromodulation Laboratory, Li Ka Shing Faculty of Medicine, School of Biomedical Sciences, the University of Hong Kong, Hong Kong, P. R. China
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31
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Dynamic regulation of Z-DNA in the mouse prefrontal cortex by the RNA-editing enzyme Adar1 is required for fear extinction. Nat Neurosci 2020; 23:718-729. [PMID: 32367065 PMCID: PMC7269834 DOI: 10.1038/s41593-020-0627-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 03/19/2020] [Indexed: 01/06/2023]
Abstract
DNA forms conformational states beyond the right-handed double-helix; however, the functional relevance of these non-canonical structures in the brain remains unknown. We show that, in the prefrontal cortex of mice, the formation of one such structure, Z-DNA, is involved in the regulation of extinction memory. Z-DNA is formed during fear learning, and reduced during extinction learning, which is mediated, in part, by a direct interaction between Z-DNA and the RNA editing enzyme Adar1. Adar1 binds to Z-DNA during fear extinction learning which leads to a reduction in Z-DNA at sites where Adar1 is recruited. Knockdown of Adar1 leads to an inability to modify a previously acquired fear memory and blocks activity-dependent changes in DNA structure and RNA state; effects that are fully rescued by the introduction of full-length Adar1. These findings suggest a novel mechanism of learning-induced gene regulation dependent on both proteins which recognize DNA structure, and the state.
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32
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Mimicking Age-Associated Gadd45γ Dysregulation Results in Memory Impairments in Young Adult Mice. J Neurosci 2019; 40:1197-1210. [PMID: 31826946 DOI: 10.1523/jneurosci.1621-19.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 11/08/2019] [Accepted: 12/05/2019] [Indexed: 01/19/2023] Open
Abstract
Age-related memory loss is observed across multiple mammalian species and preferentially affects hippocampus-dependent memory. Memory impairments are characterized by accelerated decay of spatial memories. Nevertheless, the molecular mechanisms underlying these deficits are still largely unknown. Here, we investigated the expression and function of the growth arrest DNA damage (Gadd45) family during aging and cognition, respectively. We report that aging impairs the expression of Gadd45γ in the hippocampus of cognitively impaired male mice. Mimicking this decrease in young adult male mice led to age-like memory deficits in hippocampus-dependent memory tasks. Gadd45γ reduction impaired the activity of key components of the mitogen-activated protein kinase (MAPK) pathway (p38 and JNK) in mouse hippocampal cultures. Furthermore, we found that activation of downstream targets, such as ATF-2, c-Jun, and CREB (cAMP response element-binding protein), was disrupted. Finally, we showed that Gadd45γ is required for induction of key early- and late-response genes that have been associated with aging. Together, these findings indicate that Gadd45γ expression regulates cognitive abilities and synapse-to-nucleus communication and suggest Gadd45γ dysfunction as a potential mechanism contributing to age-related cognitive impairments.SIGNIFICANCE STATEMENT A high percentage of subjects experience age-related memory loss that burdens daily performance. Although many advances have been made, the precise changes in the brain governing these deficits are unclear. Identifying molecular processes that are required for cognition and are altered during old age is crucial to develop preventive or therapeutic strategies. Here, we show that baseline and learning-induced expression of the growth arrest DNA damage (Gadd45) γ is selectively impaired in the hippocampus of aged mice with cognitive deficits. Next, we show that modeling this impairment in young adult mice with normal cognitive performance disrupts long- and short-term memories in an age-like manner. Finally, we demonstrate that Gadd45γ regulates synapse-to-nucleus communication processes that are needed for plasticity-associated gene expression.
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33
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Leighton LJ, Wei W, Marshall PR, Ratnu VS, Li X, Zajaczkowski EL, Spadaro PA, Khandelwal N, Kumar A, Bredy TW. Disrupting the hippocampal Piwi pathway enhances contextual fear memory in mice. Neurobiol Learn Mem 2019; 161:202-209. [PMID: 30965112 DOI: 10.1016/j.nlm.2019.04.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 03/27/2019] [Accepted: 04/01/2019] [Indexed: 12/26/2022]
Abstract
The Piwi pathway is a conserved gene regulatory mechanism comprised of Piwi-like proteins and Piwi-interacting RNAs, which modulates gene expression via RNA interference and through interaction with epigenetic mechanisms. The mammalian Piwi pathway has been defined by its role in transposon control during spermatogenesis; however, despite an increasing number of studies demonstrating its expression in the nervous system, relatively little is known about its function in neurons or potential contribution to behavioural regulation. We have discovered that all three Piwi-like genes are expressed in the adult mouse brain, and that viral-mediated knockdown of the Piwi-like genes Piwil1 and Piwil2 in the dorsal hippocampus leads to enhanced contextual fear memory without affecting generalised anxiety. These results implicate the Piwi pathway in behavioural regulation in the adult mammalian brain, likely through modulation of plasticity-related gene expression.
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Affiliation(s)
- Laura J Leighton
- Cognitive Neuroepigenetics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Wei Wei
- Cognitive Neuroepigenetics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Paul R Marshall
- Cognitive Neuroepigenetics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Vikram Singh Ratnu
- Cognitive Neuroepigenetics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Xiang Li
- Cognitive Neuroepigenetics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Esmi L Zajaczkowski
- Cognitive Neuroepigenetics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Paola A Spadaro
- Cognitive Neuroepigenetics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Nitin Khandelwal
- CSIR-Centre for Cellular and Molecular Biology (CCMB), Hyderabad 500007, India
| | - Arvind Kumar
- CSIR-Centre for Cellular and Molecular Biology (CCMB), Hyderabad 500007, India
| | - Timothy W Bredy
- Cognitive Neuroepigenetics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
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34
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Aparisi Rey A, Karaulanov E, Sharopov S, Arab K, Schäfer A, Gierl M, Guggenhuber S, Brandes C, Pennella L, Gruhn WH, Jelinek R, Maul C, Conrad A, Kilb W, Luhmann HJ, Niehrs C, Lutz B. Gadd45α modulates aversive learning through post-transcriptional regulation of memory-related mRNAs. EMBO Rep 2019; 20:embr.201846022. [PMID: 30948457 PMCID: PMC6549022 DOI: 10.15252/embr.201846022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 02/22/2019] [Accepted: 03/07/2019] [Indexed: 01/25/2023] Open
Abstract
Learning is essential for survival and is controlled by complex molecular mechanisms including regulation of newly synthesized mRNAs that are required to modify synaptic functions. Despite the well‐known role of RNA‐binding proteins (RBPs) in mRNA functionality, their detailed regulation during memory consolidation is poorly understood. This study focuses on the brain function of the RBP Gadd45α (growth arrest and DNA damage‐inducible protein 45 alpha, encoded by the Gadd45a gene). Here, we find that hippocampal memory and long‐term potentiation are strongly impaired in Gadd45a‐deficient mice, a phenotype accompanied by reduced levels of memory‐related mRNAs. The majority of the Gadd45α‐regulated transcripts show unusually long 3′ untranslated regions (3′UTRs) that are destabilized in Gadd45a‐deficient mice via a transcription‐independent mechanism, leading to reduced levels of the corresponding proteins in synaptosomes. Moreover, Gadd45α can bind specifically to these memory‐related mRNAs. Our study reveals a new function for extended 3′UTRs in memory consolidation and identifies Gadd45α as a novel regulator of mRNA stability.
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Affiliation(s)
- Alejandro Aparisi Rey
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | | | - Salim Sharopov
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | | | | | | | - Stephan Guggenhuber
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Caroline Brandes
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Luigi Pennella
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | | | - Ruth Jelinek
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Christina Maul
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Andrea Conrad
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Werner Kilb
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Christof Niehrs
- Institute of Molecular Biology, Mainz, Germany .,Division of Molecular Embryology, DKFZ-ZMBH Alliance, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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35
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Marshall PR, Bredy TW. Neuroepigenetic mechanisms underlying fear extinction: emerging concepts. Psychopharmacology (Berl) 2019; 236:133-142. [PMID: 30506235 PMCID: PMC7293886 DOI: 10.1007/s00213-018-5084-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 10/16/2018] [Indexed: 12/11/2022]
Abstract
An understanding of how memory is acquired and how it can be modified in fear-related anxiety disorders, with the enhancement of failing memories on one side and a reduction or elimination of traumatic memories on the other, is a key unmet challenge in the fields of neuroscience and neuropsychiatry. The latter process depends on an important form of learning called fear extinction, where a previously acquired fear-related memory is decoupled from its ability to control behaviour through repeated non-reinforced exposure to the original fear-inducing cue. Although simple in description, fear extinction relies on a complex pattern of brain region and cell-type specific processes, some of which are unique to this form of learning and, for better or worse, contribute to the inherent instability of fear extinction memory. Here, we explore an emerging layer of biology that may compliment and enrich the synapse-centric perspective of fear extinction. As opposed to the more classically defined role of protein synthesis in the formation of fear extinction memory, a neuroepigenetic view of the experience-dependent gene expression involves an appreciation of dynamic changes in the state of the entire cell: from a transient change in plasticity at the level of the synapse, to potentially more persistent long-term effects within the nucleus. A deeper understanding of neuroepigenetic mechanisms and how they influence the formation and maintenance of fear extinction memory has the potential to enable the development of more effective treatment approaches for fear-related neuropsychiatric conditions.
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Affiliation(s)
- Paul R Marshall
- Cognitive Neuroepigenetics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.
| | - Timothy W Bredy
- Cognitive Neuroepigenetics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
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