1
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Liu J, Wang Y, Liu X, Han J, Tian Y. Spatiotemporal changes in Netrin/Dscam1 signaling dictate axonal projection direction in Drosophila small ventral lateral clock neurons. eLife 2024; 13:RP96041. [PMID: 39052321 PMCID: PMC11272162 DOI: 10.7554/elife.96041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024] Open
Abstract
Axon projection is a spatial- and temporal-specific process in which the growth cone receives environmental signals guiding axons to their final destination. However, the mechanisms underlying changes in axonal projection direction without well-defined landmarks remain elusive. Here, we present evidence showcasing the dynamic nature of axonal projections in Drosophila's small ventral lateral clock neurons (s-LNvs). Our findings reveal that these axons undergo an initial vertical projection in the early larval stage, followed by a subsequent transition to a horizontal projection in the early-to-mid third instar larvae. The vertical projection of s-LNv axons correlates with mushroom body calyx expansion, while the s-LNv-expressed Down syndrome cell adhesion molecule (Dscam1) interacts with Netrins to regulate the horizontal projection. During a specific temporal window, locally newborn dorsal clock neurons secrete Netrins, facilitating the transition of axonal projection direction in s-LNvs. Our study establishes a compelling in vivo model to probe the mechanisms of axonal projection direction switching in the absence of clear landmarks. These findings underscore the significance of dynamic local microenvironments in the complementary regulation of axonal projection direction transitions.
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Affiliation(s)
- Jingjing Liu
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast UniversityNanjingChina
| | - Yuedong Wang
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast UniversityNanjingChina
| | - Xian Liu
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast UniversityNanjingChina
| | - Junhai Han
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast UniversityNanjingChina
- Co-innovation Center of Neuroregeneration, Nantong UniversityNantongChina
| | - Yao Tian
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast UniversityNanjingChina
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2
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Huang X, Li Q, Xu Y, Li A, Wang S, Chen Y, Zhang C, Zhang X, Wang H, Lv C, Sun B, Li S, Kang L, Chen B. A neural m 6A pathway regulates behavioral aggregation in migratory locusts. SCIENCE CHINA. LIFE SCIENCES 2024; 67:1242-1254. [PMID: 38478296 DOI: 10.1007/s11427-023-2476-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 10/07/2023] [Indexed: 06/07/2024]
Abstract
RNA N6-methyladenosine (m6A), as the most abundant modification of messenger RNA, can modulate insect behaviors, but its specific roles in aggregation behaviors remain unexplored. Here, we conducted a comprehensive molecular and physiological characterization of the individual components of the methyltransferase and demethylase in the migratory locust Locusta migratoria. Our results demonstrated that METTL3, METTL14 and ALKBH5 were dominantly expressed in the brain and exhibited remarkable responses to crowding or isolation. The individual knockdown of methyltransferases (i.e., METTL3 and METTL14) promoted locust movement and conspecific attraction, whereas ALKBH5 knockdown induced a behavioral shift toward the solitary phase. Furthermore, global transcriptome profiles revealed that m6A modification could regulate the orchestration of gene expression to fine tune the behavioral aggregation of locusts. In summary, our in vivo characterization of the m6A functions in migratory locusts clearly demonstrated the crucial roles of the m6A pathway in effectively modulating aggregation behaviors.
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Affiliation(s)
- Xianliang Huang
- School of Life Science, Institutes of Life Science and Green Development, Hebei University, Baoding, 071002, China
| | - Qing Li
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yanan Xu
- Institute of Health Sciences, Anhui University, Hefei, 230601, China
| | - Ang Li
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shanzheng Wang
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yusheng Chen
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Chunrui Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xia Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hailin Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100101, China
| | - Cong Lv
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100101, China
| | - Baofa Sun
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shaoqin Li
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Le Kang
- School of Life Science, Institutes of Life Science and Green Development, Hebei University, Baoding, 071002, China.
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Bing Chen
- School of Life Science, Institutes of Life Science and Green Development, Hebei University, Baoding, 071002, China.
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3
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Lv P, Yang X, Du J. LKRSDH-dependent histone modifications of insulin-like peptide sites contribute to age-related circadian rhythm changes. Nat Commun 2024; 15:3336. [PMID: 38637528 PMCID: PMC11026460 DOI: 10.1038/s41467-024-47740-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 04/10/2024] [Indexed: 04/20/2024] Open
Abstract
To understand aging impact on the circadian rhythm, we screened for factors influencing circadian changes during aging. Our findings reveal that LKRSDH mutation significantly reduces rhythmicity in aged flies. RNA-seq identifies a significant increase in insulin-like peptides (dilps) in LKRSDH mutants due to the combined effects of H3R17me2 and H3K27me3 on transcription. Genetic evidence suggests that LKRSDH regulates age-related circadian rhythm changes through art4 and dilps. ChIP-seq analyzes whole genome changes in H3R17me2 and H3K27me3 histone modifications in young and old flies with LKRSDH mutation and controls. The results reveal a correlation between H3R17me2 and H3K27me3, underscoring the role of LKRSDH in regulating gene expression and modification levels during aging. Overall, our study demonstrates that LKRSDH-dependent histone modifications at dilps sites contribute to age-related circadian rhythm changes. This data offers insights and a foundational reference for aging research by unveiling the relationship between LKRSDH and H3R17me2/H3K27me3 histone modifications in aging.
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Affiliation(s)
- Pengfei Lv
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Xingzhuo Yang
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Juan Du
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China.
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4
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Long DM, Cravetchi O, Chow ES, Allen C, Kretzschmar D. The amyloid precursor protein intracellular domain induces sleep disruptions and its nuclear localization fluctuates in circadian pacemaker neurons in Drosophila and mice. Neurobiol Dis 2024; 192:106429. [PMID: 38309627 DOI: 10.1016/j.nbd.2024.106429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 11/17/2023] [Accepted: 02/01/2024] [Indexed: 02/05/2024] Open
Abstract
The most prominent symptom of Alzheimer's disease (AD) is cognitive decline; however, sleep and other circadian disruptions are also common in AD patients. Sleep disruptions have been connected with memory problems and therefore the changes in sleep patterns observed in AD patients may also actively contribute to cognitive decline. However, the underlying molecular mechanisms that connect sleep disruptions and AD are unclear. A characteristic feature of AD is the formation of plaques consisting of Amyloid-β (Aβ) peptides generated by cleavage of the Amyloid Precursor Protein (APP). Besides Aβ, APP cleavage generates several other fragments, including the APP intracellular domain (AICD) that has been linked to transcriptional regulation and neuronal homeostasis. Here we show that overexpression of the AICD reduces the early evening expression of two core clock genes and disrupts the sleep pattern in flies. Analyzing the subcellular localization of the AICD in pacemaker neurons, we found that the AICD levels in the nucleus are low during daytime but increase at night. While this pattern of nuclear AICD persisted with age, the nighttime levels were higher in aged flies. Increasing the cleavage of the fly APP protein also disrupted AICD nuclear localization. Lastly, we show that the day/nighttime nuclear pattern of the AICD is also detectable in neurons in the suprachiasmatic nucleus of mice and that it also changes with age. Together, these data suggest that AD-associated changes in APP processing and the subsequent changes in AICD levels may cause sleep disruptions in AD.
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Affiliation(s)
- Dani M Long
- Oregon Institute of Occupational Health Sciences, Oregon Health and Science University, Portland, OR 97239, USA.
| | - Olga Cravetchi
- Oregon Institute of Occupational Health Sciences, Oregon Health and Science University, Portland, OR 97239, USA
| | - Eileen S Chow
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA
| | - Charles Allen
- Oregon Institute of Occupational Health Sciences, Oregon Health and Science University, Portland, OR 97239, USA
| | - Doris Kretzschmar
- Oregon Institute of Occupational Health Sciences, Oregon Health and Science University, Portland, OR 97239, USA
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5
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Basavarajappa BS, Subbanna S. Unlocking the epigenetic symphony: histone acetylation's impact on neurobehavioral change in neurodegenerative disorders. Epigenomics 2024; 16:331-358. [PMID: 38321930 PMCID: PMC10910622 DOI: 10.2217/epi-2023-0428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 01/23/2024] [Indexed: 02/08/2024] Open
Abstract
Recent genomics and epigenetic advances have empowered the exploration of DNA/RNA methylation and histone modifications crucial for gene expression in response to stress, aging and disease. Interest in understanding neuronal plasticity's epigenetic mechanisms, influencing brain rewiring amid development, aging and neurodegenerative disorders, continues to grow. Histone acetylation dysregulation, a commonality in diverse brain disorders, has become a therapeutic focus. Histone acetyltransferases and histone deacetylases have emerged as promising targets for neurodegenerative disorder treatment. This review delves into histone acetylation regulation, potential therapies and future perspectives for disorders like Alzheimer's, Parkinson's and Huntington's. Exploring genetic-environmental interplay through models and studies reveals molecular changes, behavioral insights and early intervention possibilities targeting the epigenome in at-risk individuals.
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Affiliation(s)
- Balapal S Basavarajappa
- Center for Dementia Research, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
- Molecular Imaging & Neuropathology Area, New York State Psychiatric Institute, NY 10032, USA
- Department of Psychiatry, Columbia University Irving Medical Center, NY 10032, USA
- Department of Psychiatry, New York University Langone Medical Center, NY 10016, USA
| | - Shivakumar Subbanna
- Center for Dementia Research, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
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6
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Giri S, Mehta R, Mallick BN. REM Sleep Loss-Induced Elevated Noradrenaline Plays a Significant Role in Neurodegeneration: Synthesis of Findings to Propose a Possible Mechanism of Action from Molecule to Patho-Physiological Changes. Brain Sci 2023; 14:8. [PMID: 38275513 PMCID: PMC10813190 DOI: 10.3390/brainsci14010008] [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: 12/01/2023] [Accepted: 12/17/2023] [Indexed: 01/27/2024] Open
Abstract
Wear and tear are natural processes for all living and non-living bodies. All living cells and organisms are metabolically active to generate energy for their routine needs, including for survival. In the process, the cells are exposed to oxidative load, metabolic waste, and bye-products. In an organ, the living non-neuronal cells divide and replenish the lost or damaged cells; however, as neuronal cells normally do not divide, they need special feature(s) for their protection, survival, and sustenance for normal functioning of the brain. The neurons grow and branch as axons and dendrites, which contribute to the formation of synapses with near and far neurons, the basic scaffold for complex brain functions. It is necessary that one or more basic and instinct physiological process(es) (functions) is likely to contribute to the protection of the neurons and maintenance of the synapses. It is known that rapid eye movement sleep (REMS), an autonomic instinct behavior, maintains brain functioning including learning and memory and its loss causes dysfunctions. In this review we correlate the role of REMS and its loss in synaptogenesis, memory consolidation, and neuronal degeneration. Further, as a mechanism of action, we will show that REMS maintains noradrenaline (NA) at a low level, which protects neurons from oxidative damage and maintains neuronal growth and synaptogenesis. However, upon REMS loss, the level of NA increases, which withdraws protection and causes apoptosis and loss of synapses and neurons. We propose that the latter possibly causes REMS loss associated neurodegenerative diseases and associated symptoms.
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Affiliation(s)
- Shatrunjai Giri
- Department of Biosciences, Manipal University Jaipur, Jaipur 303007, India;
| | - Rachna Mehta
- Amity Institute of Neuropsychology & Neurosciences, Amity University, Noida 201301, India;
| | - Birendra Nath Mallick
- Amity Institute of Neuropsychology & Neurosciences, Amity University, Noida 201301, India;
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7
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Armour EM, Thomas CM, Greco G, Bhatnagar A, Elefant F. Experience-dependent Tip60 nucleocytoplasmic transport is regulated by its NLS/NES sequences for neuroplasticity gene control. Mol Cell Neurosci 2023; 127:103888. [PMID: 37598897 PMCID: PMC11337217 DOI: 10.1016/j.mcn.2023.103888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 08/14/2023] [Accepted: 08/16/2023] [Indexed: 08/22/2023] Open
Abstract
Nucleocytoplasmic transport (NCT) in neurons is critical for enabling proteins to enter the nucleus and regulate plasticity genes in response to environmental cues. Such experience-dependent (ED) neural plasticity is central for establishing memory formation and cognitive function and can influence the severity of neurodegenerative disorders like Alzheimer's disease (AD). ED neural plasticity is driven by histone acetylation (HA) mediated epigenetic mechanisms that regulate dynamic activity-dependent gene transcription profiles in response to neuronal stimulation. Yet, how histone acetyltransferases (HATs) respond to extracellular cues in the in vivo brain to drive HA-mediated activity-dependent gene control remains unclear. We previously demonstrated that extracellular stimulation of rat hippocampal neurons in vitro triggers Tip60 HAT nuclear import with concomitant synaptic gene induction. Here, we focus on investigating Tip60 HAT subcellular localization and NCT specifically in neuronal activity-dependent gene control by using the learning and memory mushroom body (MB) region of the Drosophila brain as a powerful in vivo cognitive model system. We used immunohistochemistry (IHC) to compare the subcellular localization of Tip60 HAT in the Drosophila brain under normal conditions and in response to stimulation of fly brain neurons in vivo either by genetically inducing potassium channels activation or by exposure to natural positive ED conditions. Furthermore, we found that both inducible and ED condition-mediated neural induction triggered Tip60 nuclear import with concomitant induction of previously identified Tip60 target genes and that Tip60 levels in both the nucleus and cytoplasm were significantly decreased in our well-characterized Drosophila AD model. Mutagenesis of a putative nuclear localization signal (NLS) sequence and nuclear export signal (NES) sequence that we identified in the Drosophila Tip60 protein revealed that both are functionally required for appropriate Tip60 subcellular localization. Our results support a model by which neuronal stimulation triggers Tip60 NCT via its NLS and NES sequences to promote induction of activity-dependent neuroplasticity gene transcription and that this process may be disrupted in AD.
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Affiliation(s)
- Ellen M Armour
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Christina M Thomas
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Gabrielle Greco
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Akanksha Bhatnagar
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Felice Elefant
- Department of Biology, Drexel University, Philadelphia, PA, United States of America.
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8
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Deschain T, Fabricius J, Berendt M, Fredholm M, Karlskov-Mortensen P. The first genome-wide association study concerning idiopathic epilepsy in Petit Basset Griffon Vendeen. Anim Genet 2021; 52:762-766. [PMID: 34383319 DOI: 10.1111/age.13128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/22/2021] [Indexed: 11/28/2022]
Abstract
The dog breed Petit Basset Griffon Vendeen has a relatively high prevalence of idiopathic epilepsy compared to other dog breeds and previous studies have suggested a genetic cause of the disease in this breed. Based on these observations, a genome-wide association study was performed to identify possible epilepsy-causing loci. The study included 30 unaffected and 23 affected dogs, genotyping of 170K SNPs, and data analysis using plink and emmax. Suggestive associations at CFA13, CFA24 and CFA35 were identified with markers close to three strong candidate genes. However, subsequent sequencing of exons of the three genes did not reveal sequence variations, which could explain development of the disease. This is, to our knowledge, the first report on loci and genes with a possible connection to idiopathic epilepsy in Petit Basset Griffon Vendeen. However, further studies are needed to conclusively identify the genetic cause of idiopathic epilepsy in this dog breed.
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Affiliation(s)
- T Deschain
- Department of Veterinary and Animal Sciences, Animal Genetics, Bioinformatics & Breeding, University of Copenhagen, Gronnegaardsvej 3, Frederiksberg C, DK-1870, Denmark
| | - J Fabricius
- Department of Veterinary and Animal Sciences, Animal Genetics, Bioinformatics & Breeding, University of Copenhagen, Gronnegaardsvej 3, Frederiksberg C, DK-1870, Denmark
| | - M Berendt
- Section for Surgery, Neurology & Cardiology, Faculty of Health and Medical Sciences, University Hospital for Companion Animals, University of Copenhagen, Dyrlaegevej 16, Frederiksberg C, DK-1870, Denmark
| | - M Fredholm
- Department of Veterinary and Animal Sciences, Animal Genetics, Bioinformatics & Breeding, University of Copenhagen, Gronnegaardsvej 3, Frederiksberg C, DK-1870, Denmark
| | - P Karlskov-Mortensen
- Department of Veterinary and Animal Sciences, Animal Genetics, Bioinformatics & Breeding, University of Copenhagen, Gronnegaardsvej 3, Frederiksberg C, DK-1870, Denmark
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9
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Beaver M, Karisetty BC, Zhang H, Bhatnagar A, Armour E, Parmar V, Brown R, Xiang M, Elefant F. Chromatin and transcriptomic profiling uncover dysregulation of the Tip60 HAT/HDAC2 epigenomic landscape in the neurodegenerative brain. Epigenetics 2021; 17:786-807. [PMID: 34369292 PMCID: PMC9336495 DOI: 10.1080/15592294.2021.1959742] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Disruption of histone acetylation-mediated gene control is a critical step in Alzheimer’s Disease (AD), yet chromatin analysis of antagonistic histone acetyltransferases (HATs) and histone deacetylases (HDACs) causing these alterations remains uncharacterized. We report the first Tip60 HAT versus HDAC2 chromatin (ChIP-seq) and transcriptional (RNA-seq) profiling study in Drosophila melanogaster brains that model early human AD. We find Tip60 and HDAC2 predominantly recruited to identical neuronal genes. Moreover, AD brains exhibit robust genome-wide early alterations that include enhanced HDAC2 and reduced Tip60 binding and transcriptional dysregulation. Orthologous human genes to co-Tip60/HDAC2 D. melanogaster neural targets exhibit conserved disruption patterns in AD patient hippocampi. Notably, we discovered distinct transcription factor binding sites close or within Tip60/HDAC2 co-peaks in neuronal genes, implicating them in coenzyme recruitment. Increased Tip60 protects against transcriptional dysregulation and enhanced HDAC2 enrichment genome-wide. We advocate Tip60 HAT/HDAC2 mediated epigenetic neuronal gene disruption as a genome-wide initial causal event in AD.
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Affiliation(s)
- Mariah Beaver
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | | | - Haolin Zhang
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Akanksha Bhatnagar
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Ellen Armour
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Visha Parmar
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Reshma Brown
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Merry Xiang
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Felice Elefant
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
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10
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Jugder BE, Kamareddine L, Watnick PI. Microbiota-derived acetate activates intestinal innate immunity via the Tip60 histone acetyltransferase complex. Immunity 2021; 54:1683-1697.e3. [PMID: 34107298 DOI: 10.1016/j.immuni.2021.05.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/05/2021] [Accepted: 05/24/2021] [Indexed: 02/06/2023]
Abstract
Microbe-derived acetate activates the Drosophila immunodeficiency (IMD) pathway in a subset of enteroendocrine cells (EECs) of the anterior midgut. In these cells, the IMD pathway co-regulates expression of antimicrobial and enteroendocrine peptides including tachykinin, a repressor of intestinal lipid synthesis. To determine whether acetate acts on a cell surface pattern recognition receptor or an intracellular target, we asked whether acetate import was essential for IMD signaling. Mutagenesis and RNA interference revealed that the putative monocarboxylic acid transporter Tarag was essential for enhancement of IMD signaling by dietary acetate. Interference with histone deacetylation in EECs augmented transcription of genes regulated by the steroid hormone ecdysone including IMD targets. Reduced expression of the histone acetyltransferase Tip60 decreased IMD signaling and blocked rescue by dietary acetate and other sources of intracellular acetyl-CoA. Thus, microbe-derived acetate induces chromatin remodeling within enteroendocrine cells, co-regulating host metabolism and intestinal innate immunity via a Tip60-steroid hormone axis that is conserved in mammals.
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Affiliation(s)
- Bat-Erdene Jugder
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Layla Kamareddine
- Department of Biomedical Sciences, College of Health Sciences, QU Health, Qatar University, Doha, Qatar; Biomedical Research Center, Qatar University, Doha, Qatar; Biomedical and Pharmaceutical Research Unit, QU Health, Qatar University, Doha, Qatar
| | - Paula I Watnick
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
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11
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Li Z, Rasmussen LJ. TIP60 in aging and neurodegeneration. Ageing Res Rev 2020; 64:101195. [PMID: 33091598 DOI: 10.1016/j.arr.2020.101195] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/29/2020] [Accepted: 10/14/2020] [Indexed: 02/06/2023]
Abstract
Epigenetic modification of chromatin, including histone methylation and acetylation, plays critical roles in eukaryotic cells and has a significant impact on chromatin structure/accessibility, gene regulation and, susceptibility to aging, neurodegenerative disease, cancer, and other age-related diseases. This article reviews the current advances on TIP60/KAT5, a major histone acetyltransferase with diverse functions in eukaryotes, with emphasis on its regulation of autophagy, proteasome-dependent protein turnover, RNA transcription, DNA repair, circadian rhythms, learning and memory, and other neurological functions implicated in aging and neurodegeneration. Moreover, the promising therapeutic potential of TIP60 is discussed to target Alzheimer's disease and other neurological diseases.
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12
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He Q, Du J, Wei L, Zhao Z. AKH-FOXO pathway regulates starvation-induced sleep loss through remodeling of the small ventral lateral neuron dorsal projections. PLoS Genet 2020; 16:e1009181. [PMID: 33104699 PMCID: PMC7644095 DOI: 10.1371/journal.pgen.1009181] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 11/05/2020] [Accepted: 10/08/2020] [Indexed: 11/18/2022] Open
Abstract
Starvation caused by adverse feeding stresses or food shortages has been reported to result in sleep loss in animals. However, how the starvation signal interacts with the central nervous system is still unknown. Here, the adipokinetic hormone (AKH)-Fork head Box-O (FOXO) pathway is shown to respond to energy change and adjust the sleep of Drosophila through remodeling of the s-LNv (small ventral lateral neurons) dorsal projections. Our results show that starvation prevents flies from going to sleep after the first light-dark transition. The LNvs are required for starvation-induced sleep loss through extension of the pigment dispersing factor (PDF)-containing s-LNv dorsal projections. Further studies reveal that loss of AKH or AKHR (akh receptor) function blocks starvation-induced extension of s-LNv dorsal projections and rescues sleep suppression during food deprivation. FOXO, which has been reported to regulate synapse plasticity of neurons, acts as starvation response factor downstream of AKH, and down regulation of FOXO level considerably alleviates the influence of starvation on s-LNv dorsal projections and sleep. Taking together, our results outline the transduction pathways between starvation signal and sleep, and reveal a novel functional site for sleep regulation.
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Affiliation(s)
- Qiankun He
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Juan Du
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Liya Wei
- College of Life Science, Hebei University, Baoding, China
| | - Zhangwu Zhao
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
- * E-mail:
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13
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Humbert J, Salian S, Makrythanasis P, Lemire G, Rousseau J, Ehresmann S, Garcia T, Alasiri R, Bottani A, Hanquinet S, Beaver E, Heeley J, Smith ACM, Berger SI, Antonarakis SE, Yang XJ, Côté J, Campeau PM. De Novo KAT5 Variants Cause a Syndrome with Recognizable Facial Dysmorphisms, Cerebellar Atrophy, Sleep Disturbance, and Epilepsy. Am J Hum Genet 2020; 107:564-574. [PMID: 32822602 PMCID: PMC7477011 DOI: 10.1016/j.ajhg.2020.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 07/21/2020] [Indexed: 12/11/2022] Open
Abstract
KAT5 encodes an essential lysine acetyltransferase, previously called TIP60, which is involved in regulating gene expression, DNA repair, chromatin remodeling, apoptosis, and cell proliferation; but it remains unclear whether variants in this gene cause a genetic disease. Here, we study three individuals with heterozygous de novo missense variants in KAT5 that affect normally invariant residues, with one at the chromodomain (p.Arg53His) and two at or near the acetyl-CoA binding site (p.Cys369Ser and p.Ser413Ala). All three individuals have cerebral malformations, seizures, global developmental delay or intellectual disability, and severe sleep disturbance. Progressive cerebellar atrophy was also noted. Histone acetylation assays with purified variant KAT5 demonstrated that the variants decrease or abolish the ability of the resulting NuA4/TIP60 multi-subunit complexes to acetylate the histone H4 tail in chromatin. Transcriptomic analysis in affected individual fibroblasts showed deregulation of multiple genes that control development. Moreover, there was also upregulated expression of PER1 (a key gene involved in circadian control) in agreement with sleep anomalies in all of the individuals. In conclusion, dominant missense KAT5 variants cause histone acetylation deficiency with transcriptional dysregulation of multiples genes, thereby leading to a neurodevelopmental syndrome with sleep disturbance, cerebellar atrophy, and facial dysmorphisms, and suggesting a recognizable syndrome.
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Affiliation(s)
- Jonathan Humbert
- St-Patrick Research Group in Basic Oncology, Laval University Cancer Research Center, Axe Oncologie du Centre de Recherche du Centre Hospitalier Universitaire de Quebec-Université Laval, Quebec City, QC G1R 3S3, Canada
| | - Smrithi Salian
- Sainte-Justine Hospital Research Center, University of Montreal, Montreal, QC H3T 1C5, Canada
| | - Periklis Makrythanasis
- Biomedical Research Foundation of the Academy of Athens, Athens 115 27, Greece; Department of Genetic Medicine and Development, University of Geneva Medical School and Geneva University Hospitals, 1211 Geneva, Switzerland
| | - Gabrielle Lemire
- Sainte-Justine Hospital Research Center, University of Montreal, Montreal, QC H3T 1C5, Canada
| | - Justine Rousseau
- Sainte-Justine Hospital Research Center, University of Montreal, Montreal, QC H3T 1C5, Canada
| | - Sophie Ehresmann
- Sainte-Justine Hospital Research Center, University of Montreal, Montreal, QC H3T 1C5, Canada
| | - Thomas Garcia
- Sainte-Justine Hospital Research Center, University of Montreal, Montreal, QC H3T 1C5, Canada
| | - Rami Alasiri
- Rosalind and Morris Goodman Cancer Research Centre, Department of Medicine, McGill University, Montreal, QC H3A 1A3, Canada
| | - Armand Bottani
- Service of Genetic Medicine, Geneva University Hospitals, 1211 Geneva, Switzerland
| | - Sylviane Hanquinet
- Unit of Pediatric Radiology, Geneva University Hospitals, 1211 Geneva, Switzerland
| | - Erin Beaver
- Mercy Kids Genetics, St. Louis, MO 63141, USA
| | | | - Ann C M Smith
- Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20894, USA
| | - Seth I Berger
- Children's National Health System, Washington, DC 20010, USA
| | - Stylianos E Antonarakis
- Department of Genetic Medicine and Development, University of Geneva Medical School and Geneva University Hospitals, 1211 Geneva, Switzerland
| | - Xiang-Jiao Yang
- Rosalind and Morris Goodman Cancer Research Centre, Department of Medicine, McGill University, Montreal, QC H3A 1A3, Canada
| | - Jacques Côté
- St-Patrick Research Group in Basic Oncology, Laval University Cancer Research Center, Axe Oncologie du Centre de Recherche du Centre Hospitalier Universitaire de Quebec-Université Laval, Quebec City, QC G1R 3S3, Canada
| | - Philippe M Campeau
- Sainte-Justine Hospital Research Center, University of Montreal, Montreal, QC H3T 1C5, Canada.
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14
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Phenotypic and molecular features underlying neurodegeneration of motor neurons derived from spinal and bulbar muscular atrophy patients. Neurobiol Dis 2019; 124:1-13. [DOI: 10.1016/j.nbd.2018.10.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 10/11/2018] [Accepted: 10/28/2018] [Indexed: 12/17/2022] Open
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15
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Anreiter I, Biergans SD, Sokolowski MB. Epigenetic regulation of behavior in Drosophila melanogaster. Curr Opin Behav Sci 2019. [DOI: 10.1016/j.cobeha.2018.06.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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16
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Restoring Tip60 HAT/HDAC2 Balance in the Neurodegenerative Brain Relieves Epigenetic Transcriptional Repression and Reinstates Cognition. J Neurosci 2018; 38:4569-4583. [PMID: 29654189 DOI: 10.1523/jneurosci.2840-17.2018] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 03/26/2018] [Accepted: 04/06/2018] [Indexed: 12/16/2022] Open
Abstract
Cognitive decline is a debilitating hallmark during preclinical stages of Alzheimer's disease (AD), yet the causes remain unclear. Because histone acetylation homeostasis is critical for mediating epigenetic gene control throughout neuronal development, we postulated that its misregulation contributes to cognitive impairment preceding AD pathology. Here, we show that disruption of Tip60 histone acetlytransferase (HAT)/histone deacetylase 2 (HDAC2) homeostasis occurs early in the brain of an AD-associated amyloid precursor protein (APP) Drosophila model and triggers epigenetic repression of neuroplasticity genes well before Aβ plaques form in male and female larvae. Repressed genes display enhanced HDAC2 binding and reduced Tip60 and histone acetylation enrichment. Increasing Tip60 in the AD-associated APP brain restores Tip60 HAT/HDAC2 balance by decreasing HDAC2 levels, reverses neuroepigenetic alterations to activate synaptic plasticity genes, and reinstates brain morphology and cognition. Such Drosophila neuroplasticity gene epigenetic signatures are conserved in male and female mouse hippocampus and their expression and Tip60 function is compromised in hippocampus from AD patients. We suggest that Tip60 HAT/HDAC2-mediated epigenetic gene disruption is a critical initial step in AD that is reversed by restoring Tip60 in the brain.SIGNIFICANCE STATEMENT Mild cognitive impairment is a debilitating hallmark during preclinical stages of Alzheimer's disease (AD), yet its causes remain unclear. Although recent findings support elevated histone deacetylase 2 (HDAC2) as a cause for epigenetic repression of synaptic genes that contribute to cognitive deficits, whether alterations in histone acetlytransferase (HAT) levels that counterbalance HDAC2 repressor action occur and the identity of these HATs remain unknown. We demonstrate that disruption of Tip60 HAT/HDAC2 homeostasis occurs early in the AD Drosophila brain and triggers epigenetic repression of neuroplasticity genes before Aβ plaques form. Increasing Tip60 in the AD brain restores Tip60 HAT/HDAC2 balance, reverses neuroepigenetic alterations to activate synaptic genes, and reinstates brain morphology and cognition. Our data suggest that disruption of the Tip60 HAT/HDAC2 balance is a critical initial step in AD.
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Abstract
Sleep deprivation disrupts the lives of millions of people every day and has a profound impact on the molecular biology of the brain. These effects begin as changes within a neuron, at the DNA and RNA level, and result in alterations in neuronal plasticity and dysregulation of many cognitive functions including learning and memory. The epigenome plays a critical role in regulating gene expression in the context of memory storage. In this review article, we begin by describing the effects of epigenetic alterations on the regulation of gene expression, focusing on the most common epigenetic mechanisms: (i) DNA methylation; (ii) histone modifications; and (iii) non-coding RNAs. We then discuss evidence suggesting that sleep loss impacts the epigenome and that these epigenetic alterations might mediate the changes in cognition seen following disruption of sleep. The link between sleep and the epigenome is only beginning to be elucidated, but clear evidence exists that epigenetic alterations occur following sleep deprivation. In the future, these changes to the epigenome could be utilized as biomarkers of sleep loss or as therapeutic targets for sleep-related disorders.
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Affiliation(s)
- Marie E Gaine
- Department of Molecular Physiology and Biophysics, Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Snehajyoti Chatterjee
- Department of Molecular Physiology and Biophysics, Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Ted Abel
- Department of Molecular Physiology and Biophysics, Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
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18
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O'Callaghan EK, Green EW, Franken P, Mongrain V. Omics Approaches in Sleep-Wake Regulation. Handb Exp Pharmacol 2018; 253:59-81. [PMID: 29796779 DOI: 10.1007/164_2018_125] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Although sleep seems an obvious and simple behaviour, it is extremely complex involving numerous interactions both at the neuronal and the molecular levels. While we have gained detailed insight into the molecules and neuronal networks responsible for the circadian organization of sleep and wakefulness, the molecular underpinnings of the homeostatic aspect of sleep regulation are still unknown and the focus of a considerable research effort. In the last 20 years, the development of techniques allowing the simultaneous measurement of hundreds to thousands of molecular targets (i.e. 'omics' approaches) has enabled the unbiased study of the molecular pathways regulated by and regulating sleep. In this chapter, we will review how the different omics approaches, including transcriptomics, epigenomics, proteomics, and metabolomics, have advanced sleep research. We present relevant data in the framework of the two-process model in which circadian and homeostatic processes interact to regulate sleep. The integration of the different omics levels, known as 'systems genetics', will eventually lead to a better understanding of how information flows from the genome, to molecules, to networks, and finally to sleep both in health and disease.
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Affiliation(s)
- Emma K O'Callaghan
- Center for Advanced Research in Sleep Medicine and Research Center, Hôpital du Sacré-Coeur de Montréal, Montreal, QC, Canada.,Department of Neuroscience, Université de Montréal, Montreal, QC, Canada
| | - Edward W Green
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Paul Franken
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Valérie Mongrain
- Center for Advanced Research in Sleep Medicine and Research Center, Hôpital du Sacré-Coeur de Montréal, Montreal, QC, Canada. .,Department of Neuroscience, Université de Montréal, Montreal, QC, Canada.
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19
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Abstract
Sleep is essential for health and cognition, but the molecular and neural mechanisms of sleep regulation are not well understood. We recently reported the identification of TARANIS (TARA) as a sleep-promoting factor that acts in a previously unknown arousal center in Drosophila. tara mutants exhibit a dose-dependent reduction in sleep amount of up to ∼60%. TARA and its mammalian homologs, the Trip-Br (Transcriptional Regulators Interacting with PHD zinc fingers and/or Bromodomains) family of proteins, are primarily known as transcriptional coregulators involved in cell cycle progression, and contain a conserved Cyclin-A (CycA) binding homology domain. We found that tara and CycA synergistically promote sleep, and CycA levels are reduced in tara mutants. Additional data demonstrated that Cyclin-dependent kinase 1 (Cdk1) antagonizes tara and CycA to promote wakefulness. Moreover, we identified a subset of CycA expressing neurons in the pars lateralis, a brain region proposed to be analogous to the mammalian hypothalamus, as an arousal center. In this Extra View article, we report further characterization of tara mutants and provide an extended discussion of our findings and future directions within the framework of a working model, in which a network of cell cycle genes, tara, CycA, and Cdk1, interact in an arousal center to regulate sleep.
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Affiliation(s)
- Dinis J S Afonso
- a Department of Neuroscience ; the Farber Institute for Neurosciences; and Kimmel Cancer Center; Thomas Jefferson University ; Philadelphia , PA USA.,b Life and Health Sciences Research Institute (ICVS); School of Health Sciences; University of Minho ; 4710-057 Braga , Portugal.,c ICVS/3B's; PT Government Associate Laboratory ; 4710-057 Braga/Guimarães ; Portugal
| | - Daniel R Machado
- a Department of Neuroscience ; the Farber Institute for Neurosciences; and Kimmel Cancer Center; Thomas Jefferson University ; Philadelphia , PA USA.,b Life and Health Sciences Research Institute (ICVS); School of Health Sciences; University of Minho ; 4710-057 Braga , Portugal.,c ICVS/3B's; PT Government Associate Laboratory ; 4710-057 Braga/Guimarães ; Portugal
| | - Kyunghee Koh
- a Department of Neuroscience ; the Farber Institute for Neurosciences; and Kimmel Cancer Center; Thomas Jefferson University ; Philadelphia , PA USA
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20
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Song Q, Feng G, Huang Z, Chen X, Chen Z, Ping Y. Aberrant Axonal Arborization of PDF Neurons Induced by Aβ42-Mediated JNK Activation Underlies Sleep Disturbance in an Alzheimer's Model. Mol Neurobiol 2016; 54:6317-6328. [PMID: 27718103 DOI: 10.1007/s12035-016-0165-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 09/27/2016] [Indexed: 12/15/2022]
Abstract
Impaired sleep patterns are common symptoms of Alzheimer's disease (AD). Cellular mechanisms underlying sleep disturbance in AD remain largely unknown. Here, using a Drosophila Aβ42 AD model, we show that Aβ42 markedly decreases sleep in a large population, which is accompanied with postdevelopmental axonal arborization of wake-promoting pigment-dispersing factor (PDF) neurons. The arborization is mediated in part via JNK activation and can be reversed by decreasing JNK signaling activity. Axonal arborization and impaired sleep are correlated in Aβ42 and JNK kinase hemipterous mutant flies. Image reconstruction revealed that these aberrant fibers preferentially project to pars intercerebralis (PI), a fly brain region analogous to the mammalian hypothalamus. Moreover, PDF signaling in PI neurons was found to modulate sleep/wake activities, suggesting that excessive release of PDF by these aberrant fibers may lead to the impaired sleep in Aβ42 flies. Finally, inhibition of JNK activation in Aβ42 flies restores nighttime sleep loss, decreases Aβ42 accumulation, and attenuates neurodegeneration. These data provide a new mechanism by which sleep disturbance could be induced by Aβ42 burden, a key initiator of a complex pathogenic cascade in AD.
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Affiliation(s)
- Qian Song
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China.,Shanghai Key Laboratory of Psychotic Disorders (No.13dz2260500), Shanghai Mental Health Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Ge Feng
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zehua Huang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China.,School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China
| | - Xiaoman Chen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China.,School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China
| | - Zhaohuan Chen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China.,School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China.,Institute of Systems Biomedicine, Collaborative Innovation Center of Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yong Ping
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China. .,Shanghai Key Laboratory of Psychotic Disorders (No.13dz2260500), Shanghai Mental Health Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200030, China.
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21
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Ganai SA, Banday S, Farooq Z, Altaf M. Modulating epigenetic HAT activity for reinstating acetylation homeostasis: A promising therapeutic strategy for neurological disorders. Pharmacol Ther 2016; 166:106-22. [DOI: 10.1016/j.pharmthera.2016.07.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 06/28/2016] [Indexed: 01/30/2023]
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22
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Dissel S, Klose M, Donlea J, Cao L, English D, Winsky-Sommerer R, van Swinderen B, Shaw PJ. Enhanced sleep reverses memory deficits and underlying pathology in Drosophila models of Alzheimer's disease. Neurobiol Sleep Circadian Rhythms 2016; 2:15-26. [PMID: 29094110 PMCID: PMC5662006 DOI: 10.1016/j.nbscr.2016.09.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
To test the hypothesis that sleep can reverse cognitive impairment during Alzheimer's disease, we enhanced sleep in flies either co-expressing human amyloid precursor protein and Beta-secretase (APP:BACE), or in flies expressing human tau. The ubiquitous expression of APP:BACE or human tau disrupted sleep. The sleep deficits could be reversed and sleep could be enhanced when flies were administered the GABA-A agonist 4,5,6,7-tetrahydroisoxazolo-[5,4-c]pyridine-3-ol (THIP). Expressing APP:BACE disrupted both Short-term memory (STM) and Long-term memory (LTM) as assessed using Aversive Phototaxic Suppression (APS) and courtship conditioning. Flies expressing APP:BACE also showed reduced levels of the synaptic protein discs large (DLG). Enhancing sleep in memory-impaired APP:BACE flies fully restored both STM and LTM and restored DLG levels. Sleep also restored STM to flies expressing human tau. Using live-brain imaging of individual clock neurons expressing both tau and the cAMP sensor Epac1-camps, we found that tau disrupted cAMP signaling. Importantly, enhancing sleep in flies expressing human tau restored proper cAMP signaling. Thus, we demonstrate that sleep can be used as a therapeutic to reverse deficits that accrue during the expression of toxic peptides associated with Alzheimer's disease. THIP can be used to enhance sleep in two Drosophila models of Alzheimer's disease. Enhanced sleep reverses memory deficits in fly's expressing human APP:BACE and tau. Enhanced sleep restores cAMP levels in clock neurons expressing tau. Sleep can be used as a therapeutic to reverse Alzheimer's disease related deficits.
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Affiliation(s)
- Stephane Dissel
- Department of Neuroscience, Washington University in St. Louis, 660 S. Euclid Ave, St. Louis, Missouri, U.S.A
| | - Markus Klose
- Department of Neuroscience, Washington University in St. Louis, 660 S. Euclid Ave, St. Louis, Missouri, U.S.A
| | - Jeff Donlea
- Department of Neurobiology, University of California: Los Angeles Los Angeles, California, U.S.A
| | - Lijuan Cao
- Department of Neuroscience, Washington University in St. Louis, 660 S. Euclid Ave, St. Louis, Missouri, U.S.A
| | - Denis English
- Department of Neuroscience, Washington University in St. Louis, 660 S. Euclid Ave, St. Louis, Missouri, U.S.A
| | - Raphaelle Winsky-Sommerer
- Surrey Sleep Research Centre, Faculty of Health and Medical Sciences University of Surrey Guildford Surrey, GU2 7XH, United Kingdom
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, Brisbane Qld 4072 Australia
| | - Paul J Shaw
- Department of Neuroscience, Washington University in St. Louis, 660 S. Euclid Ave, St. Louis, Missouri, U.S.A
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Abstract
Sleep disorders in humans are increasingly appreciated to be not only widespread but also detrimental to multiple facets of physical and mental health. Recent work has begun to shed light on the mechanistic basis of sleep disorders like insomnia, restless legs syndrome, narcolepsy, and a host of others, but a more detailed genetic and molecular understanding of how sleep goes awry is lacking. Over the past 15 years, studies in Drosophila have yielded new insights into basic questions regarding sleep function and regulation. More recently, powerful genetic approaches in the fly have been applied toward studying primary human sleep disorders and other disease states associated with dysregulated sleep. In this review, we discuss the contribution of Drosophila to the landscape of sleep biology, examining not only fundamental advances in sleep neurobiology but also how flies have begun to inform pathological sleep states in humans.
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24
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Cassar M, Kretzschmar D. Analysis of Amyloid Precursor Protein Function in Drosophila melanogaster. Front Mol Neurosci 2016; 9:61. [PMID: 27507933 PMCID: PMC4960247 DOI: 10.3389/fnmol.2016.00061] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 07/13/2016] [Indexed: 01/10/2023] Open
Abstract
The Amyloid precursor protein (APP) has mainly been investigated in connection with its role in Alzheimer’s Disease (AD) due to its cleavage resulting in the production of the Aβ peptides that accumulate in the plaques characteristic for this disease. However, APP is an evolutionary conserved protein that is not only found in humans but also in many other species, including Drosophila, suggesting an important physiological function. Besides Aβ, several other fragments are produced by the cleavage of APP; large secreted fragments derived from the N-terminus and a small intracellular C-terminal fragment. Although these fragments have received much less attention than Aβ, a picture about their function is finally emerging. In contrast to mammals, which express three APP family members, Drosophila expresses only one APP protein called APP-like or APPL. Therefore APPL functions can be studied in flies without the complication that other APP family members may have redundant functions. Flies lacking APPL are viable but show defects in neuronal outgrowth in the central and peripheral nervous system (PNS) in addition to synaptic changes. Furthermore, APPL has been connected with axonal transport functions. In the adult nervous system, APPL, and more specifically its secreted fragments, can protect neurons from degeneration. APPL cleavage also prevents glial death. Lastly, APPL was found to be involved in behavioral deficits and in regulating sleep/activity patterns. This review, will describe the role of APPL in neuronal development and maintenance and briefly touch on its emerging function in circadian rhythms while an accompanying review will focus on its role in learning and memory formation.
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Affiliation(s)
- Marlène Cassar
- Oregon Institute of Occupational Health Sciences, Oregon Health and Science University Portland, OR, USA
| | - Doris Kretzschmar
- Oregon Institute of Occupational Health Sciences, Oregon Health and Science University Portland, OR, USA
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25
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Xu S, Panikker P, Iqbal S, Elefant F. Tip60 HAT Action Mediates Environmental Enrichment Induced Cognitive Restoration. PLoS One 2016; 11:e0159623. [PMID: 27454757 PMCID: PMC4959735 DOI: 10.1371/journal.pone.0159623] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 07/06/2016] [Indexed: 12/14/2022] Open
Abstract
Environmental enrichment (EE) conditions have beneficial effects for reinstating cognitive ability in neuropathological disorders like Alzheimer's disease (AD). While EE benefits involve epigenetic gene control mechanisms that comprise histone acetylation, the histone acetyltransferases (HATs) involved remain largely unknown. Here, we examine a role for Tip60 HAT action in mediating activity- dependent beneficial neuroadaptations to EE using the Drosophila CNS mushroom body (MB) as a well-characterized cognition model. We show that flies raised under EE conditions display enhanced MB axonal outgrowth, synaptic marker protein production, histone acetylation induction and transcriptional activation of cognition linked genes when compared to their genotypically identical siblings raised under isolated conditions. Further, these beneficial changes are impaired in both Tip60 HAT mutant flies and APP neurodegenerative flies. While EE conditions provide some beneficial neuroadaptive changes in the APP neurodegenerative fly MB, such positive changes are significantly enhanced by increasing MB Tip60 HAT levels. Our results implicate Tip60 as a critical mediator of EE-induced benefits, and provide broad insights into synergistic behavioral and epigenetic based therapeutic approaches for treatment of cognitive disorder.
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Affiliation(s)
- Songjun Xu
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Priyalakshmi Panikker
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Sahira Iqbal
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Felice Elefant
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
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26
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Xu S, Elefant F. Tip off the HAT- Epigenetic control of learning and memory by Drosophila Tip60. Fly (Austin) 2016; 9:22-8. [PMID: 26327426 DOI: 10.1080/19336934.2015.1080887] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Disruption of epigenetic gene control mechanisms involving histone acetylation in the brain causes cognitive impairment, a debilitating hallmark of most neurodegenerative disorders. Histone acetylation regulates cognitive gene expression via chromatin packaging control in neurons. Unfortunately, the histone acetyltransferases (HATs) that generate such neural epigenetic signatures and their mechanisms of action remain unclear. Our recent findings provide insight into this question by demonstrating that Tip60 HAT action is critical for morphology and function of the mushroom body (MB), the learning and memory center in the Drosophila brain. We show that Tip60 is robustly produced in MB Kenyon cells and extending axonal lobes and that targeted MB Tip60 HAT loss results in axonal outgrowth disruption. Functional consequences of loss and gain of Tip60 HAT levels in the MB are evidenced by defects in memory. Tip60 ChIP-Seq analysis reveals enrichment for genes that function in cognitive processes and accordingly, key genes representing these pathways are misregulated in the Tip60 HAT mutant fly brain. Remarkably, increasing levels of Tip60 in the MB rescues learning and memory deficits resulting from Alzheimer's disease associated amyloid precursor protein (APP) induced neurodegeneration. Our studies highlight the potential of HAT activators as a therapeutic option for cognitive disorders.
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Affiliation(s)
- Songjun Xu
- a Department of Biology ; Drexel University ; Philadelphia , PA USA
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27
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Peng F, Zhao Y, Huang X, Chen C, Sun L, Zhuang L, Xue L. Loss of Polo ameliorates APP-induced Alzheimer's disease-like symptoms in Drosophila. Sci Rep 2015; 5:16816. [PMID: 26597721 PMCID: PMC4657023 DOI: 10.1038/srep16816] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 10/15/2015] [Indexed: 12/13/2022] Open
Abstract
The amyloid precursor protein (APP) has been implicated in the pathogenesis of Alzheimer’s disease (AD). Despite extensive studies, little is known about the regulation of APP’s functions in vivo. Here we report that expression of human APP in Drosophila, in the same temporal-spatial pattern as its homolog APPL, induced morphological defects in wings and larval NMJ, larva and adult locomotion dysfunctions, male choice disorder and lifespan shortening. To identify additional genes that modulate APP functions, we performed a genetic screen and found that loss of Polo, a key regulator of cell cycle, partially suppressed APP-induced morphological and behavioral defects in larval and adult stages. Finally, we showed that eye-specific expression of APP induced retina degeneration and cell cycle re-entry, both phenotypes were mildly ameliorated by loss of Polo. These results suggest Polo is an important in vivo regulator of the pathological functions of APP, and provide insight into the role of cell cycle re-entry in AD pathogenesis.
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Affiliation(s)
- Fei Peng
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Yu Zhao
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Xirui Huang
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Changyan Chen
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Lili Sun
- School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, P.R. China
| | - Luming Zhuang
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Lei Xue
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
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Schmidt RL, Sheeley SL. Mating and memory: an educational primer for use with "epigenetic control of learning and memory in Drosophila by Tip60 HAT action". Genetics 2015; 200:21-8. [PMID: 25953906 PMCID: PMC4423364 DOI: 10.1534/genetics.115.176313] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 03/12/2015] [Indexed: 01/21/2023] Open
Abstract
An article by Xu et al. in the December 2014 issue of GENETICS can be used to illustrate epigenetic modification of gene expression, reverse genetic manipulation, genetic/epigenetic influence on behavioral studies, and studies using the Drosophila model organism applied to human disease. This Primer provides background information; technical explanations of genetic, biochemical, and behavioral approaches from the study; and an example of an approach for classroom use with discussion questions to aid in student comprehension of the research article.
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Affiliation(s)
- Rebecca L Schmidt
- Department of Biology and Chemistry, Upper Iowa University, Fayette, Iowa 52132
| | - Sara L Sheeley
- Department of Biology and Chemistry, Upper Iowa University, Fayette, Iowa 52132
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Nuclear Arc Interacts with the Histone Acetyltransferase Tip60 to Modify H4K12 Acetylation(1,2,3). eNeuro 2014; 1:eN-NWR-0019-14. [PMID: 26464963 PMCID: PMC4596143 DOI: 10.1523/eneuro.0019-14.2014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 11/10/2014] [Accepted: 11/10/2014] [Indexed: 12/12/2022] Open
Abstract
Arc is an immediate-early gene whose genetic ablation selectively abrogates long-term memory, indicating a critical role in memory consolidation. Although Arc protein is found at synapses, it also localizes to the neuronal nucleus, where its function is less understood. Nuclear Arc forms a complex with the β-spectrin isoform βSpIVΣ5 and associates with PML bodies, sites of epigenetic regulation of gene expression. We report here a novel interaction between Arc and Tip60, a histone-acetyltransferase and subunit of a chromatin-remodelling complex, using biochemistry and super-resolution microscopy in primary rat hippocampal neurons. Arc and βSpIVΣ5 are recruited to nuclear Tip60 speckles, and the three proteins form a tight complex that localizes to nuclear perichromatin regions, sites of transcriptional activity. Neuronal activity-induced expression of Arc (1) increases endogenous nuclear Tip60 puncta, (2) recruits Tip60 to PML bodies, and (3) increases histone acetylation of Tip60 substrate H4K12, a learning-induced chromatin modification. These mechanisms point to an epigenetic role for Arc in regulating memory consolidation.
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Abstract
Disruption of epigenetic gene control mechanisms in the brain causes significant cognitive impairment that is a debilitating hallmark of most neurodegenerative disorders, including Alzheimer's disease (AD). Histone acetylation is one of the best characterized of these epigenetic mechanisms that is critical for regulating learning- and memory- associated gene expression profiles, yet the specific histone acetyltransferases (HATs) that mediate these effects have yet to be fully characterized. Here, we investigate an epigenetic role for the HAT Tip60 in learning and memory formation using the Drosophila CNS mushroom body (MB) as a well-characterized cognition model. We show that Tip60 is endogenously expressed in the Kenyon cells, the intrinsic neurons of the MB, and in the MB axonal lobes. Targeted loss of Tip60 HAT activity in the MB causes thinner and shorter axonal lobes while increasing Tip60 HAT levels cause no morphological defects. Functional consequences of both loss and gain of Tip60 HAT levels in the MB are evidenced by defects in immediate-recall memory. Our ChIP-Seq analysis reveals that Tip60 target genes are enriched for functions in cognitive processes, and, accordingly, key genes representing these pathways are misregulated in the Tip60 HAT mutant fly brain. Remarkably, we find that both learning and immediate-recall memory deficits that occur under AD-associated, amyloid precursor protein (APP)-induced neurodegenerative conditions can be effectively rescued by increasing Tip60 HAT levels specifically in the MB. Together, our findings uncover an epigenetic transcriptional regulatory role for Tip60 in cognitive function and highlight the potential of HAT activators as a therapeutic option for neurodegenerative disorders.
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31
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Sheikh BN. Crafting the brain - role of histone acetyltransferases in neural development and disease. Cell Tissue Res 2014; 356:553-73. [PMID: 24788822 DOI: 10.1007/s00441-014-1835-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 01/30/2014] [Indexed: 01/19/2023]
Abstract
The human brain is a highly specialized organ containing nearly 170 billion cells with specific functions. Development of the brain requires adequate proliferation, proper cell migration, differentiation and maturation of progenitors. This is in turn dependent on spatial and temporal coordination of gene transcription, which requires the integration of both cell intrinsic and environmental factors. Histone acetyltransferases (HATs) are one family of proteins that modulate expression levels of genes in a space- and time-dependent manner. HATs and their molecular complexes are able to integrate multiple molecular inputs and mediate transcriptional levels by acetylating histone proteins. In mammals, 19 HATs have been described and are separated into five families (p300/CBP, MYST, GNAT, NCOA and transcription-related HATs). During embryogenesis, individual HATs are expressed or activated at specific times and locations to coordinate proper development. Not surprisingly, mutations in HATs lead to severe developmental abnormalities in the nervous system and increased neurodegeneration. This review focuses on our current understanding of HATs and their biological roles during neural development.
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Affiliation(s)
- Bilal N Sheikh
- Division of Development and Cancer, The Walter and Eliza Hall Institute of Medical Research, Melbourne, 3052, Victoria, Australia,
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32
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Abstract
The circadian clock choreographs fundamental biological rhythms. This system is comprised of the master circadian pacemaker in the suprachiasmatic nucleus and associated pacemakers in other tissues that coordinate complex physiological processes and behaviors, such as sleep, feeding, and metabolism. The molecular circuitry that underlies these clocks and orchestrates circadian gene expression has been the focus of intensive investigation, and it is becoming clear that epigenetic factors are highly integrated into these networks. In this review, we draw attention to the fundamental roles played by epigenetic mechanisms in transcriptional and post-transcriptional regulation within the circadian clock system. We also highlight how alterations in epigenetic factors and mechanisms are being linked with sleep-wake disorders. These observations provide important insights into the pathogenesis and potential treatment of these disorders and implicate epigenetic deregulation in the significant but poorly understood interconnections now emerging between circadian processes and neurodegeneration, metabolic diseases, cancer, and aging.
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Affiliation(s)
- Irfan A. Qureshi
- Roslyn and Leslie Goldstein Laboratory for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Institute for Brain Disorders and Neural Regeneration, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Rose F. Kennedy Center for Research on Intellectual and Developmental Disabilities, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Mark F. Mehler
- Roslyn and Leslie Goldstein Laboratory for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Institute for Brain Disorders and Neural Regeneration, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Rose F. Kennedy Center for Research on Intellectual and Developmental Disabilities, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Ruth S. and David L. Gottesman Stem Cell Institute, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Center for Epigenomics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Increasing Tip60 HAT levels rescues axonal transport defects and associated behavioral phenotypes in a Drosophila Alzheimer's disease model. J Neurosci 2013; 33:7535-47. [PMID: 23616558 DOI: 10.1523/jneurosci.3739-12.2013] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Axonal transport defects and axonopathy are prominent in early preclinical stages of Alzheimer's disease (AD), often preceding known disease-related pathology by over a year. As epigenetic transcriptional regulatory mechanisms, such as histone acetylation, are critical for neurogenesis, it is postulated that their misregulation might be linked to early pathophysiological mechanisms that contribute to AD. The histone acetyltransferase (HAT) Tip60 epigenetically regulates genes enriched for neuronal functions and is implicated in AD via its formation of a transcriptional regulatory complex with the amyloid precursor protein (APP) intracellular domain. Disruption of APP function is associated with axonal transport defects, raising the possibility that an epigenetic role for Tip60 might also be involved. Here, we examine whether Tip60 HAT activity functions in axonal transport using Drosophila CNS motor neurons as a well-characterized transport model. We show that reduction of Tip60 HAT activity in the nervous system causes axonopathy and transport defects associated with epigenetic misregulation of certain axonal transport-linked Tip60 target genes. Functional consequences of these defects are evidenced by reduced locomotion activity of the mutant Tip60 larvae, and these phenotypes can be partially rescued with certain histone deacetylase inhibitors. Finally, we demonstrate that Tip60 function in axonal transport is mediated by APP and that, remarkably, excess Tip60 exerts a neuroprotective role in APP-induced axonal transport and functional locomotion defects. Our observations highlight a novel functional interactive role between Tip60 HAT activity and APP in axonal transport and provide insight into the importance of specific HAT modulators for cognitive disorder treatment.
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Pirooznia SK, Elefant F. A HAT for sleep?: epigenetic regulation of sleep by Tip60 in Drosophila. Fly (Austin) 2013; 7:99-104. [PMID: 23572111 DOI: 10.4161/fly.24141] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Sleep disturbances are common in neurodegenerative diseases such as Alzheimer disease (AD). Unfortunately, how AD is mechanistically linked with interference of the body's natural sleep rhythms remains unclear. Our recent findings provide insight into this question by demonstrating that sleep disruption associated with AD is driven by epigenetic changes mediated by the histone acetyltransferase (HAT) Tip60. In this study, we show that Tip60 functionally interacts with the AD associated amyloid precursor protein (APP) to regulate axonal growth of Drosophila small ventrolateral neuronal (sLNv) pacemaker cells, and their production of neuropeptide pigment dispersing factor (PDF) that stabilizes appropriate sleep-wake patterns in the fly. Loss of Tip60 HAT activity under APP neurodegenerative conditions causes decreased PDF production, retraction of the sLNv synaptic arbor required for PDF release and disruption of sleep-wake cycles in these flies. Remarkably, excess Tip60 in conjunction with APP fully rescues these sleep-wake disturbances by inducing overelaboration of the sLNv synaptic terminals and increasing PDF levels, supporting a neuroprotective role for Tip60 in these processes. Our studies highlight the importance of epigenetic based mechanisms underlying sleep disturbances in neurodegenerative diseases like AD.
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Pirooznia SK, Elefant F. Targeting specific HATs for neurodegenerative disease treatment: translating basic biology to therapeutic possibilities. Front Cell Neurosci 2013; 7:30. [PMID: 23543406 PMCID: PMC3610086 DOI: 10.3389/fncel.2013.00030] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 03/10/2013] [Indexed: 12/28/2022] Open
Abstract
Dynamic epigenetic regulation of neurons is emerging as a fundamental mechanism by which neurons adapt their transcriptional responses to specific developmental and environmental cues. While defects within the neural epigenome have traditionally been studied in the context of early developmental and heritable cognitive disorders, recent studies point to aberrant histone acetylation status as a key mechanism underlying acquired inappropriate alterations of genome structure and function in post-mitotic neurons during the aging process. Indeed, it is becoming increasingly evident that chromatin acetylation status can be impaired during the lifetime of neurons through mechanisms related to loss of function of histone acetyltransferase (HAT) activity. Several HATs have been shown to participate in vital neuronal functions such as regulation of neuronal plasticity and memory formation. As such, dysregulation of such HATs has been implicated in the pathogenesis associated with age-associated neurodegenerative diseases and cognitive decline. In order to counteract the loss of HAT function in neurodegenerative diseases, the current therapeutic strategies involve the use of small molecules called histone deacetylase (HDAC) inhibitors that antagonize HDAC activity and thus enhance acetylation levels. Although this strategy has displayed promising therapeutic effects, currently used HDAC inhibitors lack target specificity, raising concerns about their applicability. With rapidly evolving literature on HATs and their respective functions in mediating neuronal survival and higher order brain function such as learning and memory, modulating the function of specific HATs holds new promises as a therapeutic tool in neurodegenerative diseases. In this review, we focus on the recent progress in research regarding epigenetic histone acetylation mechanisms underlying neuronal activity and cognitive function. We discuss the current understanding of specific HDACs and HATs in neurodegenerative diseases and the future promising prospects of using specific HAT based therapeutic approaches.
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