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Pandi-Perumal SR, Saravanan KM, Paul S, Namasivayam GP, Chidambaram SB. Waking Up the Sleep Field: An Overview on the Implications of Genetics and Bioinformatics of Sleep. Mol Biotechnol 2024; 66:919-931. [PMID: 38198051 DOI: 10.1007/s12033-023-01009-1] [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: 08/04/2023] [Accepted: 11/28/2023] [Indexed: 01/11/2024]
Abstract
Sleep genetics is an intriguing, as yet less understood, understudied, emerging area of biological and medical discipline. A generalist may not be aware of the current status of the field given the variety of journals that have published studies on the genetics of sleep and the circadian clock over the years. For researchers venturing into this fascinating area, this review thus includes fundamental features of circadian rhythm and genetic variables impacting sleep-wake cycles. Sleep/wake pathway medication exposure and susceptibility are influenced by genetic variations, and the responsiveness of sleep-related medicines is influenced by several functional polymorphisms. This review highlights the features of the circadian timing system and then a genetic perspective on wakefulness and sleep, as well as the relationship between sleep genetics and sleep disorders. Neurotransmission genes, as well as circadian and sleep/wake receptors, exhibit functional variability. Experiments on animals and humans have shown that these genetic variants impact clock systems, signaling pathways, nature, amount, duration, type, intensity, quality, and quantity of sleep. In this regard, the overview covers research on sleep genetics, the genomic properties of several popular model species used in sleep studies, homologs of mammalian genes, sleep disorders, and related genes. In addition, the study includes a brief discussion of sleep, narcolepsy, and restless legs syndrome from the viewpoint of a model organism. It is suggested that the understanding of genetic clues on sleep function and sleep disorders may, in future, result in an evidence-based, personalized treatment of sleep disorders.
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Affiliation(s)
- Seithikurippu R Pandi-Perumal
- Centre for Experimental Pharmacology and Toxicology, Central Animal Facility, JSS Academy of Higher Education and Research, Mysuru, Karnataka, 570015, India
- Saveetha Medical College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, Tamil Nadu, 602105, India
- Division of Research and Development, Lovely Professional University, Phagwara, Punjab, 144411, India
| | - Konda Mani Saravanan
- Department of Biotechnology, Bharath Institute of Higher Education and Research, Chennai, Tamil Nadu, 600073, India
| | - Sayan Paul
- Department of Biochemistry & Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, TX, 77555, USA
| | - Ganesh Pandian Namasivayam
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), A210, Kyoto University Institute for Advanced Study, Yoshida Ushinomiya-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Saravana Babu Chidambaram
- Centre for Experimental Pharmacology and Toxicology, Central Animal Facility, JSS Academy of Higher Education and Research, Mysuru, Karnataka, 570015, India.
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education and Research, Mysuru, Karnataka, 570015, India.
- Special Interest Group - Brain, Behaviour and Cognitive Neurosciences, JSS Academy of Higher Education & Research, Mysuru, Karnataka, 570015, India.
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Sullivan LF, Barker MS, Felix PC, Vuong RQ, White BH. Neuromodulation and the toolkit for behavioural evolution: can ecdysis shed light on an old problem? FEBS J 2024; 291:1049-1079. [PMID: 36223183 PMCID: PMC10166064 DOI: 10.1111/febs.16650] [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: 06/21/2022] [Revised: 09/06/2022] [Accepted: 10/12/2022] [Indexed: 05/10/2023]
Abstract
The geneticist Thomas Dobzhansky famously declared: 'Nothing in biology makes sense except in the light of evolution'. A key evolutionary adaptation of Metazoa is directed movement, which has been elaborated into a spectacularly varied number of behaviours in animal clades. The mechanisms by which animal behaviours have evolved, however, remain unresolved. This is due, in part, to the indirect control of behaviour by the genome, which provides the components for both building and operating the brain circuits that generate behaviour. These brain circuits are adapted to respond flexibly to environmental contingencies and physiological needs and can change as a function of experience. The resulting plasticity of behavioural expression makes it difficult to characterize homologous elements of behaviour and to track their evolution. Here, we evaluate progress in identifying the genetic substrates of behavioural evolution and suggest that examining adaptive changes in neuromodulatory signalling may be a particularly productive focus for future studies. We propose that the behavioural sequences used by ecdysozoans to moult are an attractive model for studying the role of neuromodulation in behavioural evolution.
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Affiliation(s)
- Luis F Sullivan
- Section on Neural Function, Laboratory of Molecular Biology, National Institute of Mental Health, Bethesda, MD, USA
| | - Matthew S Barker
- Section on Neural Function, Laboratory of Molecular Biology, National Institute of Mental Health, Bethesda, MD, USA
| | - Princess C Felix
- Section on Neural Function, Laboratory of Molecular Biology, National Institute of Mental Health, Bethesda, MD, USA
| | - Richard Q Vuong
- Section on Neural Function, Laboratory of Molecular Biology, National Institute of Mental Health, Bethesda, MD, USA
| | - Benjamin H White
- Section on Neural Function, Laboratory of Molecular Biology, National Institute of Mental Health, Bethesda, MD, USA
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Chen CK, Kawano T, Yanagisawa M, Hayashi Y. Forward genetic screen of Caenorhabditis elegans mutants with impaired sleep reveals a crucial role of neuronal diacylglycerol kinase DGK-1 in regulating sleep. Genetics 2023; 225:iyad140. [PMID: 37682636 DOI: 10.1093/genetics/iyad140] [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: 06/17/2023] [Accepted: 07/19/2023] [Indexed: 09/10/2023] Open
Abstract
The sleep state is widely observed in animals. The molecular mechanisms underlying sleep regulation, however, remain largely unclear. In the nematode Caenorhabditis elegans, developmentally timed sleep (DTS) and stress-induced sleep (SIS) are 2 types of quiescent behaviors that fulfill the definition of sleep and share conserved sleep-regulating molecules with mammals. To identify novel sleep-regulating molecules, we conducted an unbiased forward genetic screen based on DTS phenotypes. We isolated 2 mutants, rem8 and rem10, that exhibited significantly disrupted DTS and SIS. The causal gene of the abnormal sleep phenotypes in both mutants was mapped to dgk-1, which encodes diacylglycerol kinase. Perhaps due to the diminished SIS, dgk-1 mutant worms exhibited decreased survival following exposure to a noxious stimulus. Pan-neuronal and/or cholinergic expression of dgk-1 partly rescued the dgk-1 mutant defects in DTS, SIS, and post-stress survival. Moreover, we revealed that pkc-1/nPKC participates in sleep regulation and counteracts the effect of dgk-1; the reduced DTS, SIS, and post-stress survival rate were partly suppressed in the pkc-1; dgk-1 double mutant compared with the dgk-1 single mutant. Excessive sleep observed in the pkc-1 mutant was also suppressed in the pkc-1; dgk-1 double mutant, implying that dgk-1 has a complicated mode of action. Our findings indicate that neuronal DGK-1 is essential for normal sleep and that the counterbalance between DGK-1 and PKC-1 is crucial for regulating sleep and mitigating post-stress damage.
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Affiliation(s)
- Chung-Kuan Chen
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
- Doctoral Program in Biomedical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Taizo Kawano
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Masashi Yanagisawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
- Life Science Center for Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yu Hayashi
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- Department of Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
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Palermo J, Chesi A, Zimmerman A, Sonti S, Pahl MC, Lasconi C, Brown EB, Pippin JA, Wells AD, Doldur-Balli F, Mazzotti DR, Pack AI, Gehrman PR, Grant SF, Keene AC. Variant-to-gene mapping followed by cross-species genetic screening identifies GPI-anchor biosynthesis as a regulator of sleep. SCIENCE ADVANCES 2023; 9:eabq0844. [PMID: 36608130 PMCID: PMC9821868 DOI: 10.1126/sciadv.abq0844] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 12/05/2022] [Indexed: 05/13/2023]
Abstract
Genome-wide association studies (GWAS) in humans have identified loci robustly associated with several heritable diseases or traits, yet little is known about the functional roles of the underlying causal variants in regulating sleep duration or quality. We applied an ATAC-seq/promoter focused Capture C strategy in human iPSC-derived neural progenitors to carry out a "variant-to-gene" mapping campaign that identified 88 candidate sleep effector genes connected to relevant GWAS signals. To functionally validate the role of the implicated effector genes in sleep regulation, we performed a neuron-specific RNA interference screen in the fruit fly, Drosophila melanogaster, followed by validation in zebrafish. This approach identified a number of genes that regulate sleep including a critical role for glycosylphosphatidylinositol (GPI)-anchor biosynthesis. These results provide the first physical variant-to-gene mapping of human sleep genes followed by a model organism-based prioritization, revealing a conserved role for GPI-anchor biosynthesis in sleep regulation.
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Affiliation(s)
- Justin Palermo
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
| | - Alessandra Chesi
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Amber Zimmerman
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA 19104, USA
| | - Shilpa Sonti
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Matthew C. Pahl
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Chiara Lasconi
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Elizabeth B. Brown
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
| | - James A. Pippin
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Andrew D. Wells
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA 19104, USA
| | - Fusun Doldur-Balli
- Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA 19104, USA
| | - Diego R. Mazzotti
- Division of Medical Informatics, Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS 66103, USA
- Division of Pulmonary Critical Care and Sleep Medicine, Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS 66103, USA
| | - Allan I. Pack
- Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA 19104, USA
| | - Phillip R. Gehrman
- Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, PA 19104, USA
| | - Struan F.A. Grant
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Divisions of Human Genetics and Endocrinology and Diabetes, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alex C. Keene
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
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Lee D, Oikonomou G, Prober D. Large-scale Analysis of Sleep in Zebrafish. Bio Protoc 2022; 12:e4313. [DOI: 10.21769/bioprotoc.4313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 11/18/2021] [Accepted: 12/01/2021] [Indexed: 11/02/2022] Open
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Keenan BT, Galante RJ, Lian J, Zhang L, Guo X, Veatch OJ, Chesler EJ, O'Brien WT, Svenson KL, Churchill GA, Pack AI. The dihydropyrimidine dehydrogenase gene contributes to heritable differences in sleep in mice. Curr Biol 2021; 31:5238-5248.e7. [PMID: 34653361 DOI: 10.1016/j.cub.2021.09.049] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 08/25/2021] [Accepted: 09/17/2021] [Indexed: 12/27/2022]
Abstract
Many aspects of sleep are heritable, but only a few sleep-regulating genes have been reported. Here, we leverage mouse models to identify and confirm a previously unreported gene affecting sleep duration-dihydropyrimidine dehydrogenase (Dpyd). Using activity patterns to quantify sleep in 325 Diversity Outbred (DO) mice-a population with high genetic and phenotypic heterogeneity-a linkage peak for total sleep in the active lights off period was identified on chromosome 3 (LOD score = 7.14). Mice with the PWK/PhJ ancestral haplotype at this location demonstrated markedly reduced sleep. Among the genes within the linkage region, available RNA sequencing data in an independent sample of DO mice supported a highly significant expression quantitative trait locus for Dpyd, wherein reduced expression was associated with the PWK/PhJ allele. Validation studies were performed using activity monitoring and EEG/EMG recording in Collaborative Cross mouse strains with and without the PWK/PhJ haplotype at this location, as well as EEG and EMG recording of sleep and wake in Dpyd knockout mice and wild-type littermate controls. Mice lacking Dpyd had 78.4 min less sleep during the lights-off period than wild-type mice (p = 0.007; Cohen's d = -0.94). There was no difference in other measured behaviors in knockout mice, including assays evaluating cognitive-, social-, and affective-disorder-related behaviors. Dpyd encodes the rate-limiting enzyme in the metabolic pathway that catabolizes uracil and thymidine to β-alanine, an inhibitory neurotransmitter. Thus, data support β-alanine as a neurotransmitter that promotes sleep in mice.
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Affiliation(s)
- Brendan T Keenan
- Division of Sleep Medicine, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Raymond J Galante
- Division of Sleep Medicine, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Jie Lian
- Division of Sleep Medicine, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Lin Zhang
- Division of Sleep Medicine, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Xiaofeng Guo
- Division of Sleep Medicine, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Olivia J Veatch
- Department of Psychiatry & Behavioral Sciences, University of Kansas Medical Center, Kansas City, KS, USA
| | | | - W Timothy O'Brien
- Neurobehavior Testing Core, Institute for Translational and Therapeutic Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | | | | | - Allan I Pack
- Division of Sleep Medicine, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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Salazar JL, Yang SA, Yamamoto S. Post-Developmental Roles of Notch Signaling in the Nervous System. Biomolecules 2020; 10:biom10070985. [PMID: 32630239 PMCID: PMC7408554 DOI: 10.3390/biom10070985] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/25/2020] [Accepted: 06/26/2020] [Indexed: 12/14/2022] Open
Abstract
Since its discovery in Drosophila, the Notch signaling pathway has been studied in numerous developmental contexts in diverse multicellular organisms. The role of Notch signaling in nervous system development has been extensively investigated by numerous scientists, partially because many of the core Notch signaling components were initially identified through their dramatic ‘neurogenic’ phenotype of developing fruit fly embryos. Components of the Notch signaling pathway continue to be expressed in mature neurons and glia cells, which is suggestive of a role in the post-developmental nervous system. The Notch pathway has been, so far, implicated in learning and memory, social behavior, addiction, and other complex behaviors using genetic model organisms including Drosophila and mice. Additionally, Notch signaling has been shown to play a modulatory role in several neurodegenerative disease model animals and in mediating neural toxicity of several environmental factors. In this paper, we summarize the knowledge pertaining to the post-developmental roles of Notch signaling in the nervous system with a focus on discoveries made using the fruit fly as a model system as well as relevant studies in C elegans, mouse, rat, and cellular models. Since components of this pathway have been implicated in the pathogenesis of numerous psychiatric and neurodegenerative disorders in human, understanding the role of Notch signaling in the mature brain using model organisms will likely provide novel insights into the mechanisms underlying these diseases.
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Affiliation(s)
- Jose L. Salazar
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; (J.L.S.); (S.-A.Y.)
| | - Sheng-An Yang
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; (J.L.S.); (S.-A.Y.)
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; (J.L.S.); (S.-A.Y.)
- Department of Neuroscience, BCM, Houston, TX 77030, USA
- Program in Developmental Biology, BCM, Houston, TX 77030, USA
- Development, Disease Models & Therapeutics Graduate Program, BCM, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030, USA
- Correspondence: ; Tel.: +1-832-824-8119
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Abstract
Sleep is a ubiquitous and complex behavior in both its manifestation and regulation. Despite its essential role in maintaining optimal performance, health, and well-being, the genetic mechanisms underlying sleep remain poorly understood. Here, we review the forward genetic approaches undertaken in the last four years to elucidate the genes and gene pathways affecting sleep and its regulation. Despite an increasing number of studies and mining large databases, a coherent picture on “sleep” genes has yet to emerge. We highlight the results achieved by using unbiased genetic screens mainly in humans, mice, and fruit flies with an emphasis on normal sleep and make reference to lessons learned from the circadian field.
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Affiliation(s)
- Maxime Jan
- Centre for Integrative Genomics, University of Lausanne, Lausanne, 1015, Switzerland
| | - Bruce F O'Hara
- Department of Biology, University of Kentucky, Lexington, 40515, USA
| | - Paul Franken
- Centre for Integrative Genomics, University of Lausanne, Lausanne, 1015, Switzerland
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Epidermal Growth Factor Signaling Promotes Sleep through a Combined Series and Parallel Neural Circuit. Curr Biol 2019; 30:1-16.e13. [PMID: 31839447 DOI: 10.1016/j.cub.2019.10.048] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 07/12/2019] [Accepted: 10/23/2019] [Indexed: 11/20/2022]
Abstract
Sleep requires sleep-active neurons that depolarize to inhibit wake circuits. Sleep-active neurons are under the control of homeostatic mechanisms that determine sleep need. However, little is known about the molecular and circuit mechanisms that translate sleep need into the depolarization of sleep-active neurons. During many stages and conditions in C. elegans, sleep requires a sleep-active neuron called RIS. Here, we defined the transcriptome of RIS and discovered that genes of the epidermal growth factor receptor (EGFR) signaling pathway are expressed in RIS. Because of cellular stress, EGFR directly activates RIS. Activation of EGFR signaling in the ALA neuron has previously been suggested to promote sleep independently of RIS. Unexpectedly, we found that ALA activation promotes RIS depolarization. Our results suggest that ALA is a drowsiness neuron with two separable functions: (1) it inhibits specific behaviors, such as feeding, independently of RIS, (2) and it activates RIS. Whereas ALA plays a strong role in surviving cellular stress, surprisingly, RIS does not. In summary, EGFR signaling can depolarize RIS by an indirect mechanism through activation of the ALA neuron that acts upstream of the sleep-active RIS neuron and through a direct mechanism using EGFR signaling in RIS. ALA-dependent drowsiness, rather than RIS-dependent sleep bouts, appears to be important for increasing survival after cellular stress, suggesting that different types of behavioral inhibition play different roles in restoring health. VIDEO ABSTRACT.
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Gap Junctions and NCA Cation Channels Are Critical for Developmentally Timed Sleep and Arousal in Caenorhabditis elegans. Genetics 2018; 210:1369-1381. [PMID: 30323068 DOI: 10.1534/genetics.118.301551] [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] [Received: 08/28/2018] [Accepted: 10/10/2018] [Indexed: 12/16/2022] Open
Abstract
An essential characteristic of sleep is heightened arousal threshold, with decreased behavioral response to external stimuli. The molecular and cellular mechanisms underlying arousal threshold changes during sleep are not fully understood. We report that loss of UNC-7 or UNC-9 innexin function dramatically reduced sleep and decreased arousal threshold during developmentally timed sleep in Caenorhabditis elegans UNC-7 function was required in premotor interneurons and UNC-9 function was required in motor neurons in this paradigm. Simultaneous transient overexpression of UNC-7 and UNC-9 was sufficient to induce anachronistic sleep in adult animals. Moreover, loss of UNC-7 or UNC-9 suppressed the increased sleep of EGL-4 gain-of-function animals, which have increased cyclic-GMP-dependent protein kinase activity. These results suggest C. elegans gap junctions may act downstream of previously identified sleep regulators. In other paradigms, the NCA cation channels act upstream of gap junctions. Consistent with this, diminished NCA channel activity in C. elegans robustly increased arousal thresholds during sleep bouts in L4-to-adult developmentally timed sleep. Total time in sleep bouts was only modestly increased in animals lacking NCA channel auxiliary subunit UNC-79, whereas increased channel activity dramatically decreased sleep. Loss of EGL-4 or innexin proteins suppressed UNC-79 loss-of-function sleep and arousal defects. In Drosophila, the ion channel narrow abdomen, an ortholog of the C. elegans NCA channels, drive the pigment dispersing factor (PDF) neuropeptide release, regulating circadian behavior. However, in C. elegans, we found that loss of the PDF receptor PDFR-1 did not suppress gain-of-function sleep defects, suggesting an alternative downstream pathway. This study emphasizes the conservation and importance of neuronal activity modulation during sleep, and unequivocally demonstrates that gap junction function is critical for normal sleep.
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Bennett HL, Khoruzhik Y, Hayden D, Huang H, Sanders J, Walsh MB, Biron D, Hart AC. Normal sleep bouts are not essential for C. elegans survival and FoxO is important for compensatory changes in sleep. BMC Neurosci 2018; 19:10. [PMID: 29523076 PMCID: PMC5845181 DOI: 10.1186/s12868-018-0408-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 02/22/2018] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Sleep deprivation impairs learning, causes stress, and can lead to death. Notch and JNK-1 pathways impact C. elegans sleep in complex ways; these have been hypothesized to involve compensatory sleep. C. elegans DAF-16, a FoxO transcription factor, is required for homeostatic response to decreased sleep and DAF-16 loss decreases survival after sleep bout deprivation. Here, we investigate connections between these pathways and the requirement for sleep after mechanical stress. RESULTS Reduced function of Notch ligand LAG-2 or JNK-1 kinase resulted in increased time in sleep bouts during development. These animals were inappropriately easy to arouse using sensory stimulation, but only during sleep bouts. This constellation of defects suggested that poor quality sleep bouts in these animals might activate homeostatic mechanisms, driving compensatory increased sleep bouts. Testing this hypothesis, we found that DAF-16 FoxO function was required for increased sleep bouts in animals with defective lag-2 and jnk-1, as loss of daf-16 reduced sleep bouts back to normal levels. However, loss of daf-16 did not suppress arousal thresholds defects. Where DAF-16 function was required differed; in lag-2 and jnk-1 animals, daf-16 function was required in neurons or muscles, respectively, suggesting that disparate tissues can drive a coordinated response to sleep need. Sleep deprivation due to mechanical stimulation can cause death in many species, including C. elegans, suggesting that sleep is essential. We found that loss of sleep bouts in C. elegans due to genetic manipulation did not impact their survival, even in animals lacking DAF-16 function. However, we found that sleep bout deprivation was often fatal when combined with the concurrent stress of mechanical stimulation. CONCLUSIONS Together, these results in C. elegans confirm that Notch and JNK-1 signaling are required to achieve normal sleep depth, suggest that DAF-16 is required for increased sleep bouts when signaling decreases, and that failure to enter sleep bouts is not sufficient to cause death in C. elegans, unless paired with concurrent mechanical stress. These results suggest that mechanical stress may directly contribute to death observed in previous studies of sleep deprivation and/or that sleep bouts have a uniquely restorative role in C. elegans sleep.
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Affiliation(s)
- Heather L. Bennett
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, 185 Meeting Street, Providence, RI 02912 USA
| | - Yulia Khoruzhik
- Department of Neuroscience, Brown University, 185 Meeting Street, Box GL-N, Providence, RI 02912 USA
| | - Dustin Hayden
- Department of Neuroscience, Brown University, 185 Meeting Street, Box GL-N, Providence, RI 02912 USA
| | - Huiyan Huang
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110 USA
| | - Jarred Sanders
- Department of Physics, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, 929 E. 57th St., Chicago, IL 60637 USA
| | - Melissa B. Walsh
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, 185 Meeting Street, Providence, RI 02912 USA
| | - David Biron
- Department of Physics, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, 929 E. 57th St., Chicago, IL 60637 USA
| | - Anne C. Hart
- Department of Neuroscience, Brown University, 185 Meeting Street, Box GL-N, Providence, RI 02912 USA
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