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Naveed M, Chao OY, Hill JW, Yang YM, Huston JP, Cao R. Circadian neurogenetics and its implications in neurophysiology, behavior, and chronomedicine. Neurosci Biobehav Rev 2024; 157:105523. [PMID: 38142983 PMCID: PMC10872425 DOI: 10.1016/j.neubiorev.2023.105523] [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: 09/05/2023] [Revised: 12/13/2023] [Accepted: 12/20/2023] [Indexed: 12/26/2023]
Abstract
The circadian rhythm affects multiple physiological processes, and disruption of the circadian system can be involved in a range of disease-related pathways. The genetic underpinnings of the circadian rhythm have been well-studied in model organisms. Significant progress has been made in understanding how clock genes affect the physiological functions of the nervous system. In addition, circadian timing is becoming a key factor in improving drug efficacy and reducing drug toxicity. The circadian biology of the target cell determines how the organ responds to the drug at a specific time of day, thus regulating pharmacodynamics. The current review brings together recent advances that have begun to unravel the molecular mechanisms of how the circadian clock affects neurophysiological and behavioral processes associated with human brain diseases. We start with a brief description of how the ubiquitous circadian rhythms are regulated at the genetic, cellular, and neural circuit levels, based on knowledge derived from extensive research on model organisms. We then summarize the latest findings from genetic studies of human brain disorders, focusing on the role of human clock gene variants in these diseases. Lastly, we discuss the impact of common dietary factors and medications on human circadian rhythms and advocate for a broader application of the concept of chronomedicine.
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Affiliation(s)
- Muhammad Naveed
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812, USA; Department of Physiology and Pharmacology, College of Medicine and Life Sciences, The University of Toledo, Toledo, OH 43614, USA
| | - Owen Y Chao
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812, USA
| | - Jennifer W Hill
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, The University of Toledo, Toledo, OH 43614, USA
| | - Yi-Mei Yang
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812, USA; Department of Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Joseph P Huston
- Center for Behavioral Neuroscience, Institute of Experimental Psychology, Heinrich-Heine University, 40225 Düsseldorf, Germany
| | - Ruifeng Cao
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA; Department of Neurology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA.
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2
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Yamaguchi Y, Murai I, Takeda M, Doi S, Seta T, Hanada R, Kangawa K, Okamura H, Miyake T, Doi M. <i>Nmu</i>/<i>Nms</i>/<i>Gpr176</i> Triple-Deficient Mice Show Enhanced Light-Resetting of Circadian Locomotor Activity. Biol Pharm Bull 2022; 45:1172-1179. [DOI: 10.1248/bpb.b22-00260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Yoshiaki Yamaguchi
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University
| | - Iori Murai
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University
| | - Momoko Takeda
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University
| | - Shotaro Doi
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University
| | - Takehito Seta
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University
| | - Reiko Hanada
- Department of Neurophysiology, Faculty of Medicine, Oita University
| | - Kenji Kangawa
- Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute
| | - Hitoshi Okamura
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University
| | - Takahito Miyake
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University
| | - Masao Doi
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University
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3
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Bach VN, Ding J, Yeung M, Conrad T, Odeh HN, Cubberly P, Figy C, Ding HF, Trumbly R, Yeung KC. A Negative Regulatory Role for RKIP in Breast Cancer Immune Response. Cancers (Basel) 2022; 14:cancers14153605. [PMID: 35892864 PMCID: PMC9330697 DOI: 10.3390/cancers14153605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 12/10/2022] Open
Abstract
Simple Summary Breast cancer is the second most common cancer in women worldwide. Regulation of breast cancer metastasis remains an elusive phenomenon. Elucidating the mechanistic pathway of metastatic signaling may identify targets for regulating cancer metastatic potential. Raf-1 kinase inhibitor protein (RKIP) has been shown to negatively regulate signaling pathways involved in cancer progression and metastasis. RKIP may suppress metastasis of breast cancer cells by downregulating elements of the immune system. Abstract Raf-1 kinase inhibitor protein was first identified as a negative regulator of the Raf signaling pathway. Subsequently, it was shown to have a causal role in containing cancer progression and metastasis. Early studies suggested that RKIP blocks cancer progression by inhibiting the Raf-1 pathway. However, it is not clear if the RKIP tumor and metastasis suppression function involve other targets. In addition to the Raf signaling pathway, RKIP has been found to modulate several other signaling pathways, affecting diverse biological functions including immune response. Recent advances in medicine have identified both positive and negative roles of immune response in cancer initiation, progression and metastasis. It is possible that one way that RKIP exerts its effect on cancer is by targeting an immune response mechanism. Here, we provide evidence supporting the causal role of tumor and metastasis suppressor RKIP in downregulating signaling pathways involved with immune response in breast cancer cells and discuss its potential ramification on cancer therapy.
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Affiliation(s)
- Vu N. Bach
- Department of Cell & Cancer Biology, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH 43614, USA; (V.N.B.); (M.Y.); (T.C.); (H.N.O.); (P.C.); (C.F.)
| | - Jane Ding
- Georgia Cancer Center, Medical College of Georgia, Augusta University, Georgia, GA 30912, USA; (J.D.); (H.-F.D.)
| | - Miranda Yeung
- Department of Cell & Cancer Biology, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH 43614, USA; (V.N.B.); (M.Y.); (T.C.); (H.N.O.); (P.C.); (C.F.)
| | - Taylor Conrad
- Department of Cell & Cancer Biology, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH 43614, USA; (V.N.B.); (M.Y.); (T.C.); (H.N.O.); (P.C.); (C.F.)
| | - Hussain N. Odeh
- Department of Cell & Cancer Biology, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH 43614, USA; (V.N.B.); (M.Y.); (T.C.); (H.N.O.); (P.C.); (C.F.)
| | - Paige Cubberly
- Department of Cell & Cancer Biology, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH 43614, USA; (V.N.B.); (M.Y.); (T.C.); (H.N.O.); (P.C.); (C.F.)
| | - Christopher Figy
- Department of Cell & Cancer Biology, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH 43614, USA; (V.N.B.); (M.Y.); (T.C.); (H.N.O.); (P.C.); (C.F.)
| | - Han-Fei Ding
- Georgia Cancer Center, Medical College of Georgia, Augusta University, Georgia, GA 30912, USA; (J.D.); (H.-F.D.)
| | - Robert Trumbly
- Department of Cell & Cancer Biology, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH 43614, USA; (V.N.B.); (M.Y.); (T.C.); (H.N.O.); (P.C.); (C.F.)
- Department of Medical Education, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH 43614, USA
- Correspondence: (R.T.); (K.C.Y.)
| | - Kam C. Yeung
- Department of Cell & Cancer Biology, College of Medicine and Life Sciences, University of Toledo, Health Science Campus, Toledo, OH 43614, USA; (V.N.B.); (M.Y.); (T.C.); (H.N.O.); (P.C.); (C.F.)
- Correspondence: (R.T.); (K.C.Y.)
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4
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Li Q, Gu Y, Gao X, Guo X, Huang C, Liu P, Hu G, Li G, Fang W, Mai W, Wu C, Xu Z, Huang F, Liu P. Preparation of polyclonal antibody against phosphatidylethanolamine binding protein 1 recombinant protein and its functional verification in pulmonary hypertension syndrome in broilers. Int J Biol Macromol 2022; 213:19-26. [DOI: 10.1016/j.ijbiomac.2022.05.159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/04/2022] [Accepted: 05/22/2022] [Indexed: 11/26/2022]
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5
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Hoyt KR, Obrietan K. Circadian clocks, cognition, and Alzheimer's disease: synaptic mechanisms, signaling effectors, and chronotherapeutics. Mol Neurodegener 2022; 17:35. [PMID: 35525980 PMCID: PMC9078023 DOI: 10.1186/s13024-022-00537-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 04/08/2022] [Indexed: 12/20/2022] Open
Abstract
Modulation of basic biochemical and physiological processes by the circadian timing system is now recognized as a fundamental feature of all mammalian organ systems. Within the central nervous system, these clock-modulating effects are reflected in some of the most complex behavioral states including learning, memory, and mood. How the clock shapes these behavioral processes is only now beginning to be realized. In this review we describe recent findings regarding the complex set of cellular signaling events, including kinase pathways, gene networks, and synaptic circuits that are under the influence of the clock timing system and how this, in turn, shapes cognitive capacity over the circadian cycle. Further, we discuss the functional roles of the master circadian clock located in the suprachiasmatic nucleus, and peripheral oscillator populations within cortical and limbic circuits, in the gating of synaptic plasticity and memory over the circadian cycle. These findings are then used as the basis to discuss the connection between clock dysregulation and cognitive impairments resulting from Alzheimer's disease (AD). In addition, we discuss the conceptually novel idea that in AD, there is a selective disruption of circadian timing within cortical and limbic circuits, and that it is the disruption/desynchronization of these regions from the phase-entraining effects of the SCN that underlies aspects of the early- and mid-stage cognitive deficits in AD. Further, we discuss the prospect that the disruption of circadian timing in AD could produce a self-reinforcing feedback loop, where disruption of timing accelerates AD pathogenesis (e.g., amyloid deposition, oxidative stress and cell death) that in turn leads to a further disruption of the circadian timing system. Lastly, we address potential therapeutic approaches that could be used to strengthen cellular timing networks and, in turn, how these approaches could be used to improve cognitive capacity in Alzheimer's patients.
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Affiliation(s)
- Kari R Hoyt
- Division of Pharmaceutics and Pharmacology, Ohio State University, 412 Riffe Building, 12th Ave, Columbus, OH, 43210, USA.
| | - Karl Obrietan
- Department of Neuroscience, Ohio State University, Graves Hall, 333 W. 10th Ave, Columbus, OH, 43210, USA.
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6
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Aten S, Kalidindi A, Yoon H, Rumbaugh G, Hoyt KR, Obrietan K. SynGAP is expressed in the murine suprachiasmatic nucleus and regulates circadian-gated locomotor activity and light-entrainment capacity. Eur J Neurosci 2020; 53:732-749. [PMID: 33174316 DOI: 10.1111/ejn.15043] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 10/29/2020] [Accepted: 11/01/2020] [Indexed: 12/15/2022]
Abstract
The suprachiasmatic nucleus (SCN) of the hypothalamus functions as the master circadian clock. The phasing of the SCN oscillator is locked to the daily solar cycle, and an intracellular signaling cassette from the small GTPase Ras to the p44/42 mitogen-activated protein kinase (ERK/MAPK) pathway is central to this entrainment process. Here, we analyzed the expression and function of SynGAP-a GTPase-activating protein that serves as a negative regulator of Ras signaling-within the murine SCN. Using a combination of immunohistochemical and Western blotting approaches, we show that SynGAP is broadly expressed throughout the SCN. In addition, temporal profiling assays revealed that SynGAP expression is regulated over the circadian cycle, with peak expression occurring during the circadian night. Further, time-of-day-gated expression of SynGAP was not observed in clock arrhythmic BMAL1 null mice, indicating that the daily oscillation in SynGAP is driven by the inherent circadian timing mechanism. We also show that SynGAP phosphorylation at serine 1138-an event that has been found to modulate its functional efficacy-is regulated by clock time and is responsive to photic input. Finally, circadian phenotypic analysis of Syngap1 heterozygous mice revealed enhanced locomotor activity, increased sensitivity to light-evoked clock entrainment, and elevated levels of light-evoked MAPK activity, which is consistent with the role of SynGAP as a negative regulator of MAPK signaling. These findings reveal that SynGAP functions as a modulator of SCN clock entrainment, an effect that may contribute to sleep and circadian abnormalities observed in patients with SYNGAP1 gene mutations.
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Affiliation(s)
- Sydney Aten
- Department of Neuroscience, Ohio State University, Columbus, OH, USA
| | - Anisha Kalidindi
- Department of Neuroscience, Ohio State University, Columbus, OH, USA
| | - Hyojung Yoon
- Department of Neuroscience, Ohio State University, Columbus, OH, USA
| | - Gavin Rumbaugh
- Scripps Research, Department of Neuroscience, Jupiter, FL, USA.,Scripps Research, Department of Molecular Medicine, Jupiter, FL, USA
| | - Kari R Hoyt
- Division of Pharmaceutics and Pharmacology, Ohio State University, Columbus, OH, USA
| | - Karl Obrietan
- Department of Neuroscience, Ohio State University, Columbus, OH, USA
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7
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Hartsock MJ, Spencer RL. Memory and the circadian system: Identifying candidate mechanisms by which local clocks in the brain may regulate synaptic plasticity. Neurosci Biobehav Rev 2020; 118:134-162. [PMID: 32712278 DOI: 10.1016/j.neubiorev.2020.07.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 07/14/2020] [Accepted: 07/18/2020] [Indexed: 12/11/2022]
Abstract
The circadian system is an endogenous biological network responsible for coordinating near-24-h cycles in behavior and physiology with daily timing cues from the external environment. In this review, we explore how the circadian system regulates memory formation, retention, and recall. Circadian rhythms in these memory processes may arise through several endogenous pathways, and recent work highlights the importance of genetic timekeepers found locally within tissues, called local clocks. We evaluate the circadian memory literature for evidence of local clock involvement in memory, identifying potential nodes for direct interactions between local clock components and mechanisms of synaptic plasticity. Our discussion illustrates how local clocks may pervasively modulate neuronal plastic capacity, a phenomenon that we designate here as circadian metaplasticity. We suggest that this function of local clocks supports the temporal optimization of memory processes, illuminating the potential for circadian therapeutic strategies in the prevention and treatment of memory impairment.
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Affiliation(s)
- Matthew J Hartsock
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, Colorado 80309, United States.
| | - Robert L Spencer
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, Colorado 80309, United States.
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8
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Endo T. Dominant-negative antagonists of the Ras-ERK pathway: DA-Raf and its related proteins generated by alternative splicing of Raf. Exp Cell Res 2019; 387:111775. [PMID: 31843497 DOI: 10.1016/j.yexcr.2019.111775] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 12/10/2019] [Accepted: 12/11/2019] [Indexed: 12/11/2022]
Abstract
The Ras-ERK pathway regulates a variety of cellular and physiological responses, including cell proliferation, differentiation, morphogenesis during animal development, and homeostasis in adults. Deregulated activation of this pathway leads to cellular transformation and tumorigenesis as well as RASopathies. Several negative regulators of this pathway have been documented. Each of these proteins acts at particular points of the pathway, and they exert specific cellular and physiological functions. Among them, DA-Raf1 (DA-Raf), which is a splicing isoform of A-Raf and contains the Ras-binding domain but lacks the kinase domain, antagonizes the Ras-ERK pathway in a dominant-negative manner. DA-Raf induces apoptosis, skeletal myocyte differentiation, lung alveolarization, and fulfills tumor suppressor functions by interfering with the Ras-ERK pathway. After the findings of DA-Raf, several kinase-domain-truncated splicing variants of Raf proteins have also been reported. The family of these truncated proteins represents the concept that alternative splicing can generate antagonistic proteins to their full-length counterparts.
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Affiliation(s)
- Takeshi Endo
- Department of Biology, Graduate School of Science, Chiba University, 1-33 Yayoicho, Inageku, Chiba, Chiba 263-8522, Japan.
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9
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Okamoto-Uchida Y, Nishimura A, Izawa J, Hattori A, Suzuki N, Hirayama J. The Use of Chemical Compounds to Identify the Regulatory Mechanisms of Vertebrate Circadian Clocks. Curr Drug Targets 2019; 21:425-432. [PMID: 31556855 DOI: 10.2174/1389450120666190926143120] [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: 07/16/2019] [Revised: 09/04/2019] [Accepted: 09/11/2019] [Indexed: 11/22/2022]
Abstract
Circadian clocks are intrinsic, time-tracking processes that confer a survival advantage on an organism. Under natural conditions, they follow approximately a 24-h day, modulated by environmental time cues, such as light, to maximize an organism's physiological efficiency. The exact timing of this rhythm is established by cell-autonomous oscillators called cellular clocks, which are controlled by transcription-translation negative feedback loops. Studies of cell-based systems and wholeanimal models have utilized a pharmacological approach in which chemical compounds are used to identify molecular mechanisms capable of establishing and maintaining cellular clocks, such as posttranslational modifications of cellular clock regulators, chromatin remodeling of cellular clock target genes' promoters, and stability control of cellular clock components. In addition, studies with chemical compounds have contributed to the characterization of light-signaling pathways and their impact on the cellular clock. Here, the use of chemical compounds to study the molecular, cellular, and behavioral aspects of the vertebrate circadian clock system is described.
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Affiliation(s)
- Yoshimi Okamoto-Uchida
- Division of Medicinal Safety Science, National Institute of Health Sciences, Tokyo, Japan
| | - Akari Nishimura
- Department of Clinical Engineering, Faculty of Health Sciences, Komatsu University, Komatsu, Ishikawa, Japan
| | - Junko Izawa
- Department of Clinical Engineering, Faculty of Health Sciences, Komatsu University, Komatsu, Ishikawa, Japan
| | - Atsuhiko Hattori
- College of Liberal Arts and Sciences, Tokyo Medical and Dental University, Ichikawa, Chiba, Japan
| | - Nobuo Suzuki
- Noto Marine Laboratory, Division of Marine Environmental Studies, Institute of Nature and Environmental Technology, Kanazawa University, Noto-cho, Ishikawa 927-0553, Japan
| | - Jun Hirayama
- Department of Clinical Engineering, Faculty of Health Sciences, Komatsu University, Komatsu, Ishikawa, Japan
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A Symphony of Signals: Intercellular and Intracellular Signaling Mechanisms Underlying Circadian Timekeeping in Mice and Flies. Int J Mol Sci 2019; 20:ijms20092363. [PMID: 31086044 PMCID: PMC6540063 DOI: 10.3390/ijms20092363] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/10/2019] [Accepted: 05/10/2019] [Indexed: 12/11/2022] Open
Abstract
The central pacemakers of circadian timekeeping systems are highly robust yet adaptable, providing the temporal coordination of rhythms in behavior and physiological processes in accordance with the demands imposed by environmental cycles. These features of the central pacemaker are achieved by a multi-oscillator network in which individual cellular oscillators are tightly coupled to the environmental day-night cycle, and to one another via intercellular coupling. In this review, we will summarize the roles of various neurotransmitters and neuropeptides in the regulation of circadian entrainment and synchrony within the mammalian and Drosophila central pacemakers. We will also describe the diverse functions of protein kinases in the relay of input signals to the core oscillator or the direct regulation of the molecular clock machinery.
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Vasoactive intestinal peptide controls the suprachiasmatic circadian clock network via ERK1/2 and DUSP4 signalling. Nat Commun 2019; 10:542. [PMID: 30710088 PMCID: PMC6358603 DOI: 10.1038/s41467-019-08427-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 12/21/2018] [Indexed: 01/02/2023] Open
Abstract
The suprachiasmatic nucleus (SCN) co-ordinates circadian behaviour and physiology in mammals. Its cell-autonomous circadian oscillations pivot around a well characterised transcriptional/translational feedback loop (TTFL), whilst the SCN circuit as a whole is synchronised to solar time by its retinorecipient cells that express and release vasoactive intestinal peptide (VIP). The cell-autonomous and circuit-level mechanisms whereby VIP synchronises the SCN are poorly understood. We show that SCN slices in organotypic culture demonstrate rapid and sustained circuit-level circadian responses to VIP that are mediated at a cell-autonomous level. This is accompanied by changes across a broad transcriptional network and by significant VIP-directed plasticity in the internal phasing of the cell-autonomous TTFL. Signalling via ERK1/2 and tuning by its negative regulator DUSP4 are critical elements of the VIP-directed circadian re-programming. In summary, we provide detailed mechanistic insight into VIP signal transduction in the SCN at the level of genes, cells and neural circuit. The suprachiasmatic nucleus (SCN) synchronises daily rhythms of behaviour and physiology to the light-dark cycle. Vasoactive intestinal peptide (VIP) is important for mediating SCN entrainment; however, the underlying mechanisms are incompletely understood. Here, the authors show that the effects of VIP on the SCN are mediated by ERK1/2 and DUSP4.
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12
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Yamada Y, Prosser RA. Copper in the suprachiasmatic circadian clock: A possible link between multiple circadian oscillators. Eur J Neurosci 2018; 51:47-70. [PMID: 30269387 DOI: 10.1111/ejn.14181] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 09/05/2018] [Accepted: 09/17/2018] [Indexed: 01/07/2023]
Abstract
The mammalian circadian clock in the suprachiasmatic nucleus (SCN) is very robust, able to coordinate our daily physiological and behavioral rhythms with exquisite accuracy. Simultaneously, the SCN clock is highly sensitive to environmental timing cues such as the solar cycle. This duality of resiliency and sensitivity may be sustained in part by a complex intertwining of three cellular oscillators: transcription/translation, metabolic/redox, and membrane excitability. We suggest here that one of the links connecting these oscillators may be forged from copper (Cu). Cellular Cu levels are highly regulated in the brain and peripherally, and Cu affects cellular metabolism, redox state, cell signaling, and transcription. We have shown that both Cu chelation and application induce nighttime phase shifts of the SCN clock in vitro and that these treatments affect glutamate, N-methyl-D-aspartate receptor, and associated signaling processes differently. More recently we found that Cu induces mitogen-activated protein kinase-dependent phase shifts, while the mechanisms by which Cu removal induces phase shifts remain unclear. Lastly, we have found that two Cu transporters are expressed in the SCN, and that one of these transporters (ATP7A) exhibits a day/night rhythm. Our results suggest that Cu homeostasis is tightly regulated in the SCN, and that changes in Cu levels may serve as a time cue for the circadian clock. We discuss these findings in light of the existing literature and current models of multiple coupled circadian oscillators in the SCN.
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Affiliation(s)
- Yukihiro Yamada
- Department of Biochemistry & Cellular and Molecular Biology, NeuroNET Research Center, University of Tennessee, Knoxville, Tennessee
| | - Rebecca A Prosser
- Department of Biochemistry & Cellular and Molecular Biology, NeuroNET Research Center, University of Tennessee, Knoxville, Tennessee
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13
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Neben CL, Lo M, Jura N, Klein OD. Feedback regulation of RTK signaling in development. Dev Biol 2017; 447:71-89. [PMID: 29079424 DOI: 10.1016/j.ydbio.2017.10.017] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 10/17/2017] [Accepted: 10/23/2017] [Indexed: 02/07/2023]
Abstract
Precise regulation of the amplitude and duration of receptor tyrosine kinase (RTK) signaling is critical for the execution of cellular programs and behaviors. Understanding these control mechanisms has important implications for the field of developmental biology, and in recent years, the question of how augmentation or attenuation of RTK signaling via feedback loops modulates development has become of increasing interest. RTK feedback regulation is also important for human disease research; for example, germline mutations in genes that encode RTK signaling pathway components cause numerous human congenital syndromes, and somatic alterations contribute to the pathogenesis of diseases such as cancers. In this review, we survey regulators of RTK signaling that tune receptor activity and intracellular transduction cascades, with a focus on the roles of these genes in the developing embryo. We detail the diverse inhibitory mechanisms utilized by negative feedback regulators that, when lost or perturbed, lead to aberrant increases in RTK signaling. We also discuss recent biochemical and genetic insights into positive regulators of RTK signaling and how these proteins function in tandem with negative regulators to guide embryonic development.
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Affiliation(s)
- Cynthia L Neben
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco 94143, USA
| | - Megan Lo
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco 94143, USA; Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Natalia Jura
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA.
| | - Ophir D Klein
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco 94143, USA; Department of Pediatrics and Institute for Human Genetics, University of California, San Francisco, San Francisco 94143, USA.
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14
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Shinozaki A, Misawa K, Ikeda Y, Haraguchi A, Kamagata M, Tahara Y, Shibata S. Potent Effects of Flavonoid Nobiletin on Amplitude, Period, and Phase of the Circadian Clock Rhythm in PER2::LUCIFERASE Mouse Embryonic Fibroblasts. PLoS One 2017; 12:e0170904. [PMID: 28152057 PMCID: PMC5289493 DOI: 10.1371/journal.pone.0170904] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 01/12/2017] [Indexed: 12/14/2022] Open
Abstract
Flavonoids are natural polyphenols that are widely found in plants. The effects of flavonoids on obesity and numerous diseases such as cancer, diabetes, and Alzheimer’s have been well studied. However, little is known about the relationships between flavonoids and the circadian clock. In this study, we show that continuous or transient application of flavonoids to the culture medium of embryonic fibroblasts from PER2::LUCIFERASE (PER2::LUC) mice induced various modifications in the circadian clock amplitude, period, and phase. Transient application of some of the tested flavonoids to cultured cells induced a phase delay of the PER2::LUC rhythm at the down slope phase. In addition, continuous application of the polymethoxy flavonoids nobiletin and tangeretin increased the amplitude and lengthened the period of the PER2::LUC rhythm. The nobiletin-induced phase delay was blocked by co-treatment with U0126, an ERK inhibitor. In summary, among the tested flavonoids, polymethoxy flavones increased the amplitude, lengthened the period, and delayed the phase of the PER2::LUC circadian rhythm. Therefore, foods that contain polymethoxy flavones may have beneficial effects on circadian rhythm disorders and jet lag.
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Affiliation(s)
- Ayako Shinozaki
- Laboratory of Physiology and Pharmacology, School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Kenichiro Misawa
- Laboratory of Physiology and Pharmacology, School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Yuko Ikeda
- Laboratory of Physiology and Pharmacology, School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Atsushi Haraguchi
- Laboratory of Physiology and Pharmacology, School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Mayo Kamagata
- Laboratory of Physiology and Pharmacology, School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Yu Tahara
- Laboratory of Physiology and Pharmacology, School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Shigenobu Shibata
- Laboratory of Physiology and Pharmacology, School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
- * E-mail:
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15
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GRK2 Fine-Tunes Circadian Clock Speed and Entrainment via Transcriptional and Post-translational Control of PERIOD Proteins. Cell Rep 2015; 12:1272-88. [PMID: 26279567 DOI: 10.1016/j.celrep.2015.07.037] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 06/07/2015] [Accepted: 07/18/2015] [Indexed: 11/22/2022] Open
Abstract
The pacemaker properties of the suprachiasmatic nucleus (SCN) circadian clock are shaped by mechanisms that influence the expression and behavior of clock proteins. Here, we reveal that G-protein-coupled receptor kinase 2 (GRK2) modulates the period, amplitude, and entrainment characteristics of the SCN. Grk2-deficient mice show phase-dependent alterations in light-induced entrainment, slower recovery from jetlag, and longer behavioral rhythms. Grk2 ablation perturbs intrinsic rhythmic properties of the SCN, increasing amplitude and decreasing period. At the cellular level, GRK2 suppresses the transcription of the mPeriod1 gene and the trafficking of PERIOD1 and PERIOD2 proteins to the nucleus. Moreover, GRK2 can physically interact with PERIOD1/2 and promote PERIOD2 phosphorylation at Ser545, effects that may underlie its ability to regulate PERIOD1/2 trafficking. Together, our findings identify GRK2 as an important modulator of circadian clock speed, amplitude, and entrainment by controlling PERIOD at the transcriptional and post-translational levels.
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16
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Yin R, Liu X, Bi Y, Xie G, Zhang P, Meng X, Ai L, Xu R, Sun Y, Stoeger T, Ding Z. Expression of Raf kinase inhibitor protein is downregulated in response to Newcastle disease virus infection to promote viral replication. J Gen Virol 2015; 96:2579-2586. [PMID: 26297355 DOI: 10.1099/jgv.0.000228] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Newcastle disease virus (NDV) causes a severe and economically significant disease affecting almost the entire poultry industry worldwide. However, factors that affect NDV replication in host cells are poorly understood. Raf kinase inhibitory protein (RKIP) is a physiological inhibitor of c-RAF kinase and NF-κB signalling, known for their functions in the control of immune response as well as tumour invasion and metastasis. In the present study, we investigated the consequences of overexpression of host RKIP during viral infection. We demonstrate that NDV infection represses RKIP expression thereby promoting virus replication. Experimental upregulation of RKIP in turn acts as a potential antiviral defence mechanism in host cells that restricts NDV replication by repressing the activation of Raf/MEK/ERK and IκBα/NF-κB signalling pathways. Our results not only extend the concept of linking NDV-host interactions, but also reveal RKIP as a new class of protein-kinase-inhibitor protein that affects NDV replication with therapeutic potential.
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Affiliation(s)
- Renfu Yin
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, Jilin 130062, PR China
| | - Xinxin Liu
- College of Quartermaster Technology Science, Jilin University, Xi'an Road 5333, Changchun, Jilin 130062, PR China
| | - Yuhai Bi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, PR China
| | - Guangyao Xie
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, Jilin 130062, PR China
| | - Pingze Zhang
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, Jilin 130062, PR China
| | - Xin Meng
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, Jilin 130062, PR China
| | - Lili Ai
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, Jilin 130062, PR China
| | - Rongyi Xu
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, Jilin 130062, PR China
| | - Yuzhang Sun
- China Animal Health and Epidemiology Center, Qingdao, Nanjing Road 369, Qingdao, Shandong 266032, PR China
| | - Tobias Stoeger
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease (iLBD), Helmholtz Zentrum München, Ingolstädter Landstraße 1, D-85764 Neuherberg/Munich, Germany
| | - Zhuang Ding
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, Jilin 130062, PR China
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17
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Zordan MA, Sandrelli F. Circadian Clock Dysfunction and Psychiatric Disease: Could Fruit Flies have a Say? Front Neurol 2015; 6:80. [PMID: 25941512 PMCID: PMC4403521 DOI: 10.3389/fneur.2015.00080] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 03/24/2015] [Indexed: 12/15/2022] Open
Abstract
There is evidence of a link between the circadian system and psychiatric diseases. Studies in humans and mammals suggest that environmental and/or genetic disruption of the circadian system leads to an increased liability to psychiatric disease. Disruption of clock genes and/or the clock network might be related to the etiology of these pathologies; also, some genes, known for their circadian clock functions, might be associated to mental illnesses through clock-independent pleiotropy. Here, we examine the features which we believe make Drosophila melanogaster a model apt to study the role of the circadian clock in psychiatric disease. Despite differences in the organization of the clock system, the molecular architecture of the Drosophila and mammalian circadian oscillators are comparable and many components are evolutionarily related. In addition, Drosophila has a rather complex nervous system, which shares much at the cell and neurobiological level with humans, i.e., a tripartite brain, the main neurotransmitter systems, and behavioral traits: circadian behavior, learning and memory, motivation, addiction, social behavior. There is evidence that the Drosophila brain shares some homologies with the vertebrate cerebellum, basal ganglia, and hypothalamus-pituitary-adrenal axis, the dysfunctions of which have been tied to mental illness. We discuss Drosophila in comparison to mammals with reference to the: organization of the brain and neurotransmitter systems; architecture of the circadian clock; clock-controlled behaviors. We sum up current knowledge on behavioral endophenotypes, which are amenable to modeling in flies, such as defects involving sleep, cognition, or social interactions, and discuss the relationship of the circadian system to these traits. Finally, we consider if Drosophila could be a valuable asset to understand the relationship between circadian clock malfunction and psychiatric disease.
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Affiliation(s)
- Mauro Agostino Zordan
- Department of Biology, University of Padova, Padova, Italy
- Cognitive Neuroscience Center, University of Padova, Padova, Italy
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18
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Ling HH, Mendoza-Viveros L, Mehta N, Cheng HYM. Raf kinase inhibitory protein (RKIP): functional pleiotropy in the mammalian brain. Crit Rev Oncog 2015; 19:505-16. [PMID: 25597360 DOI: 10.1615/critrevoncog.2014011899] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In 1984, a cytosolic protein was isolated from bovine brain and coined phosphatidylethanolamine binding protein (PEBP) to describe its phospholipid-binding potential. Its cellular function remained elusive for more than a decade until it was discovered that PEBP had the ability to suppress the Raf1-mitogen activated protein kinase (MAPK) pathway, earning it the new name of Raf1 kinase inhibitory protein (RKIP). This milestone discovery has paved the way for numerous studies that have now extended the reach of RKIP's function to other signaling cascades, within the context of various physiological and pathophysiological systems. This review will summarize our current knowledge of the neurophysiological roles of RKIP in the mammalian brain, including its function in the circadian clock and synaptic plasticity. It will also discuss evidence for an involvement of RKIP and its derived neuropeptide, hippocampal cholinergic neurostimulating peptide (HCNP), in neural development and differentiation. Implications in certain pathologies such as Alzheimer's disease and brain cancer will be highlighted. By chronicling the diverse functions of RKIP in the brain, we hope that this review will serve as a timely resource that ignites future studies on this versatile, multifaceted protein in the nervous system.
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Affiliation(s)
- Harrod H Ling
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Lucia Mendoza-Viveros
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Neel Mehta
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Hai-Ying M Cheng
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
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19
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Iyer R, Wang TA, Gillette MU. Circadian gating of neuronal functionality: a basis for iterative metaplasticity. Front Syst Neurosci 2014; 8:164. [PMID: 25285070 PMCID: PMC4168688 DOI: 10.3389/fnsys.2014.00164] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 08/22/2014] [Indexed: 02/06/2023] Open
Abstract
Brain plasticity, the ability of the nervous system to encode experience, is a modulatory process leading to long-lasting structural and functional changes. Salient experiences induce plastic changes in neurons of the hippocampus, the basis of memory formation and recall. In the suprachiasmatic nucleus (SCN), the central circadian (~24-h) clock, experience with light at night induces changes in neuronal state, leading to circadian plasticity. The SCN's endogenous ~24-h time-generator comprises a dynamic series of functional states, which gate plastic responses. This restricts light-induced alteration in SCN state-dynamics and outputs to the nighttime. Endogenously generated circadian oscillators coordinate the cyclic states of excitability and intracellular signaling molecules that prime SCN receptivity to plasticity signals, generating nightly windows of susceptibility. We propose that this constitutes a paradigm of ~24-h iterative metaplasticity, the repeated, patterned occurrence of susceptibility to induction of neuronal plasticity. We detail effectors permissive for the cyclic susceptibility to plasticity. We consider similarities of intracellular and membrane mechanisms underlying plasticity in SCN circadian plasticity and in hippocampal long-term potentiation (LTP). The emerging prominence of the hippocampal circadian clock points to iterative metaplasticity in that tissue as well. Exploring these links holds great promise for understanding circadian shaping of synaptic plasticity, learning, and memory.
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Affiliation(s)
- Rajashekar Iyer
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign Urbana, IL, USA
| | - Tongfei A Wang
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign Urbana, IL, USA
| | - Martha U Gillette
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign Urbana, IL, USA ; Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign Urbana, IL, USA
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20
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Smarr BL, Jennings KJ, Driscoll JR, Kriegsfeld LJ. A time to remember: the role of circadian clocks in learning and memory. Behav Neurosci 2014; 128:283-303. [PMID: 24708297 PMCID: PMC4385793 DOI: 10.1037/a0035963] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The circadian system has pronounced influence on learning and memory, manifesting as marked changes in memory acquisition and recall across the day. From a mechanistic perspective, the majority of studies have investigated mammalian hippocampal-dependent learning and memory, as this system is highly tractable. The hippocampus plays a major role in learning and memory, and has the potential to integrate circadian information in many ways, including information from local, independent oscillators, and through circadian modulation of neurogenesis, synaptic remodeling, intracellular cascades, and epigenetic regulation of gene expression. These local processes are combined with input from other oscillatory systems to synergistically augment hippocampal rhythmic function. This overview presents an account of the current state of knowledge on circadian interactions with learning and memory circuitry and provides a framework for those interested in further exploring these interactions.
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Affiliation(s)
- Benjamin L. Smarr
- Department of Psychology, University of California, Berkeley, CA, 94720 USA
| | | | - Joseph R. Driscoll
- The Helen Wills Neuroscience Institute, University of California, Berkeley, CA, 94720 USA
| | - Lance J. Kriegsfeld
- Department of Psychology, University of California, Berkeley, CA, 94720 USA
- The Helen Wills Neuroscience Institute, University of California, Berkeley, CA, 94720 USA
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21
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Zhao X, Zhu X, Cheng S, Xie Y, Wang Z, Liu Y, Jiang Z, Xiao J, Guo H, Wang Y. MiR-29a/b/c regulate human circadian gene hPER1 expression by targeting its 3'UTR. Acta Biochim Biophys Sin (Shanghai) 2014; 46:313-7. [PMID: 24578160 DOI: 10.1093/abbs/gmu007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Several essential biological progresses in mammals are regulated by circadian rhythms. Though the molecular mechanisms of oscillating these circadian rhythms have been uncovered, the specific functions of the circadian genes are not very clear. It has been reported that knocking down circadian genes by microRNA is a useful strategy to explore the function of the circadian rhythms. In this study, through a forward bioinformatics screening approach, we identified miR-29a/b/c as potent inhibitors for the human circadian gene hPER1. We further found that miR-29a/b/c could directly target hPER1 3'untranslated region (UTR) and down-regulate hPER1 at both mRNA and protein expression levels in human A549 cells. Thus, our findings suggested that the expression of hPER1 is regulated by miR-29a/b/c, which may also provide a new clue for the function of hPER1.
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Affiliation(s)
- Xiyan Zhao
- Health Ministry Key Laboratory of Chronobiology, Pre-clinic and Forensic Medical School, Sichuan University, Chengdu 610041, China
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22
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Egr1 regulates lithium-induced transcription of the Period 2 (PER2) gene. Biochim Biophys Acta Mol Basis Dis 2013; 1832:1969-79. [DOI: 10.1016/j.bbadis.2013.06.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Revised: 05/22/2013] [Accepted: 06/19/2013] [Indexed: 11/19/2022]
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23
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Al-Mulla F, Bitar MS, Taqi Z, Yeung KC. RKIP: much more than Raf kinase inhibitory protein. J Cell Physiol 2013; 228:1688-702. [PMID: 23359513 DOI: 10.1002/jcp.24335] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 01/16/2013] [Indexed: 12/11/2022]
Abstract
From its discovery as a phosphatidylethanolamine-binding protein in bovine brain to its designation as a physiological inhibitor of Raf kinase protein, RKIP has emerged as a critical molecule for maintaining subdued, well-orchestrated cellular responses to stimuli. The disruption of RKIP in a wide range of pathologies, including cancer, Alzheimer's disease, and pancreatitis, makes it an exciting target for individualized therapy and disease-specific interventions. This review attempts to highlight recent advances in the RKIP field underscoring its potential role as a master modulator of many pivotal intracellular signaling cascades that control cellular growth, motility, apoptosis, genomic integrity, and therapeutic resistance. Specific biological and functional niches are highlighted to focus future research towards an enhanced understanding of the multiple roles of RKIP in health and disease.
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Affiliation(s)
- Fahd Al-Mulla
- Faculty of Medicine, Department of Pathology, Kuwait University Health Sciences Centre, Safat, Kuwait.
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24
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Raf kinase inhibitory protein is required for cerebellar long-term synaptic depression by mediating PKC-dependent MAPK activation. J Neurosci 2013; 32:14254-64. [PMID: 23055494 DOI: 10.1523/jneurosci.2812-12.2012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
It was demonstrated previously that a positive feedback loop, including protein kinase C (PKC) and mitogen-activated protein kinase (MAPK), is required for the gradual expression of cerebellar long-term depression (LTD). PKC and MAPK are mutually activated in this loop. MAPK-dependent PKC activation is likely to be mediated by phospholipase A2. On the other hand, it is not clear how PKC activates MAPK. Therefore, the entire picture of this loop was not fully understood. We here test the hypothesis that this loop is completed by the PKC substrate, Raf kinase inhibitory protein (RKIP). To test this hypothesis, we used a mutant form of RKIP that is not phosphorylated by PKC and thus constitutively inhibits Raf-1 and MEK, upstream kinases of MAPK. When this RKIP mutant was introduced into Purkinje cells of mouse cerebellar slices through patch-clamp electrodes, LTD was blocked, while wild-type (WT) RKIP had no effect on LTD. Physiological epistasis experiments demonstrated that RKIP works downstream of PKC and upstream of MAPK during LTD induction. Furthermore, biochemical analyses demonstrated that endogenous RKIP dissociates from Raf-1 and MEK during LTD induction in a PKC-dependent manner, suggesting that RKIP binding-dependent inhibition of Raf-1 and MEK is removed upon LTD induction. We therefore conclude that PKC-dependent regulation of RKIP leads to MAPK activation, with RKIP completing the positive feedback loop that is required for LTD.
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25
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Goldsmith CS, Bell-Pedersen D. Diverse roles for MAPK signaling in circadian clocks. ADVANCES IN GENETICS 2013; 84:1-39. [PMID: 24262095 DOI: 10.1016/b978-0-12-407703-4.00001-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The mitogen-activated protein kinase (MAPK) family of genes aids cells in sensing both extracellular and intracellular stimuli, and emerging data indicate that MAPKs have fundamental, yet diverse, roles in the circadian biological clock. In the mammalian suprachiasmatic nucleus (SCN), MAPK pathways can function as inputs allowing the endogenous clock to entrain to 24h environmental cycles. MAPKs can also interact physically and/or genetically with components of the molecular circadian oscillator, implying that MAPKs can affect the cycling of the clock. Finally, circadian rhythms in MAPK pathway activation exist in many different tissue types and in model organisms, providing a mechanism to coordinately control the expression tissue-specific target genes at the proper time of day. As such, it should probably not come as a surprise that MAPK signaling pathways and circadian clocks affect similar biological processes and defects in either pathway lead to many of the same types of human diseases, highlighting the need to better define the mechanisms that link these two fundamental pathways together.
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26
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MicroRNA-224 targets RKIP to control cell invasion and expression of metastasis genes in human breast cancer cells. Biochem Biophys Res Commun 2012; 425:127-33. [PMID: 22809510 DOI: 10.1016/j.bbrc.2012.07.025] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 07/09/2012] [Indexed: 11/22/2022]
Abstract
The Raf kinase inhibitor protein (RKIP) is a tumor suppressor that protects against metastasis and genomic instability. RKIP is downregulated in many types of tumors, although the mechanism for this remains unknown. MicroRNAs silence target genes via translational inhibition or target mRNA degradation, and are thus important regulators of gene expression. In the current study, we found that miR-224 expression is significantly upregulated in breast cancer cell lines, and especially in highly invasive MDA-MB-231 cells, compared to human normal breast epithelial cells. In addition, miR-224 inhibits RKIP gene expression by directly targeting its 3'-untranslated region (3'-UTR). Moreover, metastasis, as assayed by Transwell migration, 3D growth in Matrigel, and wound healing, was enhanced by ectopic expression of miR-224 and inhibited by miR-224 downregulation. Promotion of metastasis in response to miR-224 downregulation was associated with derepression of the stroma-associated RKIP target genes, CXCR4, MMP1, and OPN, which are involved in breast tumor metastasis to the bone. Taken together, our data indicate that miR-224 play an important role in metastasis of human breast cancer cells to the bone by directly suppressing the RKIP tumor suppressor.
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