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Ohdo S, Koyanagi S, Matsunaga N. Implications of biological clocks in pharmacology and pharmacokinetics of antitumor drugs. J Control Release 2023; 364:490-507. [PMID: 37918485 DOI: 10.1016/j.jconrel.2023.10.049] [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: 03/01/2022] [Revised: 10/22/2023] [Accepted: 10/30/2023] [Indexed: 11/04/2023]
Abstract
Mammalians' circadian pacemaker resides in the paired suprachiasmatic nuclei (SCN). SCN control biological rhythms such as the sleep-wake rhythm and homeostatic functions of steroid hormones and their receptors. Alterations in these biological rhythms are implicated in the outcomes of pathogenic conditions such as depression, diabetes, and cancer. Chronotherapy is about optimizing treatment to combat risks and intensity of the disease symptoms that vary depending on the time of day. Thus, conditions/diseases such as allergic rhinitis, arthritis, asthma, myocardial infarction, congestive heart failure, stroke, and peptic ulcer disease, prone to manifest severe symptoms depending on the time of day, would be benefited from chronotherapy. Monitoring rhythm, overcoming rhythm disruption, and manipulating the rhythms from the viewpoints of underlying molecular clocks are essential to enhanced chronopharmacotherapy. New drugs focused on molecular clocks are being developed to improve therapeutics. In this review, we provide a critical summary of literature reports concerning (a) the rationale/mechanisms for time-dependent dosing differences in therapeutic outcomes and safety of antitumor drugs, (b) the molecular pathways underlying biological rhythms, and (c) the possibility of pharmacotherapy based on the intra- and inter-individual variabilities from the viewpoints of the clock genes.
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Affiliation(s)
- Shigehiro Ohdo
- Department of Pharmaceutics, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-Ku, Fukuoka 812-8582, Japan.
| | - Satoru Koyanagi
- Department of Pharmaceutics, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-Ku, Fukuoka 812-8582, Japan
| | - Naoya Matsunaga
- Department of Pharmaceutics, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-Ku, Fukuoka 812-8582, Japan
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2
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Hoyt KR, Li A, Yoon H, Weisenseel Z, Watkins J, Fischer A, Obrietan K. Ribosomal S6 Kinase Regulates the Timing and Entrainment of the Mammalian Circadian Clock Located in the Suprachiasmatic Nucleus. Neuroscience 2023; 516:15-26. [PMID: 36796752 PMCID: PMC10099606 DOI: 10.1016/j.neuroscience.2023.02.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 02/01/2023] [Accepted: 02/08/2023] [Indexed: 02/16/2023]
Abstract
Previous work in the suprachiasmatic nucleus (SCN), the locus of the principal circadian clock, has shown that the activation state of the ERK/MAPK effector p90 ribosomal S6 kinase (RSK) is responsive to photic stimulation and is modulated across the circadian cycle. These data raise the prospect that RSK signaling contributes to both SCN clock timing and entrainment. Here, we found marked expression of the three main RSK isoforms (RSK1/2/3) within the SCN of C57/Bl6 mice. Further, using a combination of immunolabeling and proximity ligation assays, we show that photic stimulation led to the dissociation of RSK from ERK and the translocation of RSK from the cytoplasm to the nucleus. To test for RSK functionality following light treatment, animals received an intraventricular infusion of the selective RSK inhibitor, SL0101, 30 min prior to light (100 lux) exposure during the early circadian night (circadian time 15). Notably, the disruption of RSK signaling led to a significant reduction (∼45 min) in the phase delaying effects of light, relative to vehicle-infused mice. To test the potential contribution of RSK signaling to SCN pacemaker activity, slice cultures from a per1-Venus circadian reporter mouse line were chronically treated with SL0101. Suppression of RSK signaling led to a significant lengthening of the circadian period (∼40 min), relative to vehicle-treated slices. Together, these data reveal that RSK functions as a signaling intermediate that regulates light-evoked clock entrainment and the inherent time keeping properties of the SCN.
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Affiliation(s)
- Kari R Hoyt
- Division of Pharmaceutics and Pharmacology, Ohio State University, Columbus, OH, USA.
| | - Aiqing Li
- Department of Neuroscience, Ohio State University, Columbus, OH, USA
| | - Hyojung Yoon
- Department of Neuroscience, Ohio State University, Columbus, OH, USA
| | - Zachary Weisenseel
- Division of Pharmaceutics and Pharmacology, Ohio State University, Columbus, OH, USA
| | - Jacob Watkins
- Division of Pharmaceutics and Pharmacology, Ohio State University, Columbus, OH, USA
| | - Alex Fischer
- 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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3
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Ohdo S, Koyanagi S, Matsunaga N. Chronopharmacology of immune-related diseases. Allergol Int 2022; 71:437-447. [PMID: 35850747 DOI: 10.1016/j.alit.2022.06.006] [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: 05/22/2022] [Revised: 06/07/2022] [Accepted: 06/15/2022] [Indexed: 11/01/2022] Open
Abstract
Clock genes, circadian pacemaker resides in the paired suprachiasmatic nuclei (SCN), control various circadian rhythms in many biological processes such as physiology and behavior. Clock gene regulates many diseases such as cancer, immunological dysfunction, metabolic syndrome and sleep disorders etc. Chronotherapy is especially relevant, when the risk and/or intensity of the symptoms of disease vary predicably over time as exemplified by allergic rhinitis, arthritis, asthma, myocardial infarction, congestive heart failure, stroke, and peptic ulcer disease. Dosing time influences the effectiveness and toxicity of many drugs. The pharmacodynamics of medications as well as pharmacokinetics influences chronopharmacological phenomena. To escape from host immunity in the tumor microenvironment, cancer cells have acquired several pathways. Immune checkpoint therapy targeting programmed death 1 (PD-1) and its ligand (PD-L1) interaction had been approved for the treatment of patients with several types of cancers. Circadian expression of PD-1 is identified on tumor associated macrophages (TAMs), which is rationale for selecting the most appropriate time of day for administration of PD-1/PD-L1 inhibitors. The therapies for chronic kidney disease (CKD) are urgently needed because of a global health problem. The mechanism of the cardiac complications in mice with CKD had been related the GRP68 in circulating monocytes and serum accumulation of retinol. Development of a strategy to suppress retinol accumulation will be useful to prevent the cardiac complications of CKD. Therefore, we introduce an overview of the dosing time-dependent changes in therapeutic outcome and safety of drug for immune-related diseases.
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Affiliation(s)
- Shigehiro Ohdo
- Department of Pharmaceutics, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
| | - Satoru Koyanagi
- Department of Glocal Healthcare, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Naoya Matsunaga
- Department of Clinical Pharmacokinetics, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
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Sharma R, Parikh M, Mishra V, Sahota P, Thakkar M. Activation of dopamine D2 receptors in the medial shell region of the nucleus accumbens increases Per1 expression to enhance alcohol consumption. Addict Biol 2022; 27:e13133. [PMID: 35032086 DOI: 10.1111/adb.13133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 10/04/2021] [Accepted: 12/10/2021] [Indexed: 11/28/2022]
Abstract
Circadian genes, including Per1, in the medial shell region of nucleus accumbens (mNAcSh), regulate binge alcohol consumption. However, the upstream mechanism regulating circadian genes-induced alcohol consumption is not known. Since activation of dopamine D2 receptors (D2R) increases Per1 gene expression, we hypothesised that local infusion of quinpirole, a D2R agonist, by increasing Per1 gene expression in the mNAcSh, will increase binge alcohol consumption in mice. We performed two experiments on male C57BL/6J mice, instrumented with bilateral guide cannulas above the mNAcSh, and exposed to a 4-day drinking-in-dark (DID) paradigm. The first experiment determined the effects of bilateral infusion of quinpirole (100 ng/300 nl/site) or DMSO (Vehicle group) in the mNAcSh on Per1 gene expression and alcohol consumption. The second experiment determined the effect of antisense-induced downregulation of Per1 in the mNAcSh on the quinpirole-induced increase in alcohol consumption. Control experiments were performed by exposing the animals to sucrose (10% w/v). After the experiment, animals were euthanised, brains removed and processed for localisation of injection sites and analysis of Per1 gene expression in the mNAcSh. As compared with the DMSO, local bilateral infusion of quinpirole significantly increased the expression of Per1 in the mNAcSh along with an increase in the amount of alcohol consumed in mice exposed to DID paradigm. In addition, local antisense-induced downregulation of Per1 significantly attenuated the effects of intro-accumbal infusion of quinpirole on alcohol consumption. Our results suggest that Per1 in the mNAcSh mediates D2R activation-induced increase in alcohol consumption.
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Affiliation(s)
- Rishi Sharma
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology University of Missouri Columbia Missouri USA
| | - Meet Parikh
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology University of Missouri Columbia Missouri USA
| | - Vaibhav Mishra
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology University of Missouri Columbia Missouri USA
| | - Pradeep Sahota
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology University of Missouri Columbia Missouri USA
| | - Mahesh Thakkar
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology University of Missouri Columbia Missouri USA
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Sharma R, Parikh M, Mishra V, Soni A, Rubi S, Sahota P, Thakkar M. Antisense-induced downregulation of major circadian genes modulates the expression of histone deacetylase-2 (HDAC-2) and CREB-binding protein (CBP) in the medial shell region of nucleus accumbens of mice exposed to chronic excessive alcohol consumption. J Neurochem 2021; 161:8-19. [PMID: 34837399 DOI: 10.1111/jnc.15547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/23/2021] [Accepted: 11/23/2021] [Indexed: 12/12/2022]
Abstract
Circadian genes in the medial accumbal shell (mNAcSh) region regulate binge alcohol consumption. Here, we investigated if antisense-induced knockdown of major circadian genes (Per1, Per2, and NPAS2) in the mNAcSh of mice exposed to intermittent access two-bottle choice (IA2BC) paradigm modulates the expression of histone deacetylase-2 (HDAC-2) and CREB-binding protein (CBP), key epigenetic modifiers associated with withdrawal-associated behaviors such as anxiety. Adult male C57BL/6J mice (N = 28), surgically implanted with bilateral guide cannulas above the mNAcSh, were chronically (4 weeks) exposed to alcohol (20% v/v) or saccharin (0.03%) via IA2BC paradigm. In the fourth week, a mixture of antisense (AS-ODNs; N = 14/group) or nonsense (NS-ODNs; N = 14/group) oligodeoxynucleotides against circadian genes were bilaterally infused into the mNAcSh. Subsequently, alcohol/saccharin consumption and preference were measured followed by euthanization of animals and verification of microinjection sites by visual inspection and the expression of HDAC-2 and CBP by using RT-PCR along with the verification of antisense-induced downregulation of circadian genes in the mNAcSh. As compared with NS-ODNs, AS-ODNs infusion significantly attenuated the alcohol-induced increase in HDAC-2 and reduction in CBP expression in the mNAcSh along with a significant reduction in alcohol consumption and preference. No significant effect was observed on either saccharin consumption or preference. Our results suggest that circadian genes in the mNAcSh may have a causal to play in mediating epigenetic changes observed after chronic alcohol consumption.
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Affiliation(s)
- Rishi Sharma
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology, University of Missouri-School of Medicine, Columbia, Missouri, USA
| | - Meet Parikh
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology, University of Missouri-School of Medicine, Columbia, Missouri, USA
| | - Vaibhav Mishra
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology, University of Missouri-School of Medicine, Columbia, Missouri, USA
| | - Anshul Soni
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology, University of Missouri-School of Medicine, Columbia, Missouri, USA
| | - Sofia Rubi
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology, University of Missouri-School of Medicine, Columbia, Missouri, USA
| | - Pradeep Sahota
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology, University of Missouri-School of Medicine, Columbia, Missouri, USA
| | - Mahesh Thakkar
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology, University of Missouri-School of Medicine, Columbia, Missouri, USA
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Plante AE, Rao VP, Rizzo MA, Meredith AL. Comparative Ca 2+ channel contributions to intracellular Ca 2+ levels in the circadian clock. BIOPHYSICAL REPORTS 2021; 1:100005. [PMID: 35330949 PMCID: PMC8942421 DOI: 10.1016/j.bpr.2021.100005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 07/08/2021] [Indexed: 11/22/2022]
Abstract
Circadian rhythms in mammals are coordinated by the central clock in the brain, located in the suprachiasmatic nucleus (SCN). Multiple molecular and cellular signals display a circadian variation within SCN neurons, including intracellular Ca2+, but the mechanisms are not definitively established. SCN cytosolic Ca2+ levels exhibit a peak during the day, when both action potential firing and Ca2+ channel activity are increased, and are decreased at night, correlating with a reduction in firing rate. In this study, we employ a single-color fluorescence anisotropy reporter (FLARE), Venus FLARE-Cameleon, and polarization inverted selective-plane illumination microscopy to measure rhythmic changes in cytosolic Ca2+ in SCN neurons. Using this technique, the Ca2+ channel subtypes contributing to intracellular Ca2+ at the peak and trough of the circadian cycle were assessed using a pharmacological approach with Ca2+ channel inhibitors. Peak (218 ± 16 nM) and trough (172 ± 13 nM) Ca2+ levels were quantified, indicating a 1.3-fold circadian variance in Ca2+ concentration. Inhibition of ryanodine-receptor-mediated Ca2+ release produced a larger relative decrease in cytosolic Ca2+ at both time points compared to voltage-gated Ca2+channels. These results support the hypothesis that circadian Ca2+ rhythms in SCN neurons are predominantly driven by intracellular Ca2+ channels, although not exclusively so. The study provides a foundation for future experiments to probe Ca2+ signaling in a dynamic biological context using FLAREs.
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Affiliation(s)
- Amber E. Plante
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Vishnu P. Rao
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Megan A. Rizzo
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Andrea L. Meredith
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
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Ohdo S. Chrono-Drug Discovery and Development Based on Circadian Rhythm of Molecular, Cellular and Organ Level. Biol Pharm Bull 2021; 44:747-761. [PMID: 34078807 DOI: 10.1248/bpb.b21-00277] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The paired suprachiasmatic nuclei (SCN) is the circadian pacemaker in mammals. Clock genes ultimately regulates a vast array of circadian rhythms involved in biological, physiological and behavioral process. The clock genes are closely related to sleep disorders, metabolic syndromes, and cancer diseases. Monitoring rhythm, overcoming rhythm disruption, and manipulating rhythm from the perspective of the clock genes play an important role to improve chronopharmacotherapy. Such an approach should be achieved by overcoming the new challenges in drug delivery systems that match the circadian rhythm (Chrono-DDS). Gene and antibody delivery, targeting specific molecules for certain diseases have been focused in recent studies on pharmacotherapy. One of important candidates should also be clock genes. New drugs targeting the molecular clock are being developed to manage diseases in humans. The circadian dynamics of cancer stem cells are controlled by the tumor microenvironment and provide proof for its implication in chronotherapy against triple-negative breast cancer. To examine the relationship between the circadian clock and chronic kidney disease (CKD) exacervation leads to clarify the novel molecular mechanisms causing renal malfunction in mice with CKD. A novel inhibitor of cell cycle regulatory factors has been identified and the inhibitor repressed renal inflammation in a CKD mouse model. Therefore, this review aims to introduce the role of the molecular clock in the time-dependent dosing changes in the therapeutic effect and safety of a drug and the possibility of drug discovery and development based on the molecular clock.
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Affiliation(s)
- Shigehiro Ohdo
- Department of Pharmaceutics, Graduate School of Pharmaceutical Sciences, Kyushu University
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Uriu K, Tei H. Complementary phase responses via functional differentiation of dual negative feedback loops. PLoS Comput Biol 2021; 17:e1008774. [PMID: 33684114 PMCID: PMC7971863 DOI: 10.1371/journal.pcbi.1008774] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 03/18/2021] [Accepted: 02/05/2021] [Indexed: 11/18/2022] Open
Abstract
Multiple feedback loops are often found in gene regulations for various cellular functions. In mammalian circadian clocks, oscillations of Period1 (Per1) and Period2 (Per2) expression are caused by interacting negative feedback loops (NFLs) whose protein products with similar molecular functions repress each other. However, Per1 expression peaks earlier than Per2 in the pacemaker tissue, raising the question of whether the peak time difference reflects their different dynamical functions. Here, we address this question by analyzing phase responses of the circadian clock caused by light-induced transcription of both Per1 and Per2 mRNAs. Through mathematical analyses of dual NFLs, we show that phase advance is mainly driven by light inputs to the repressor with an earlier expression peak as Per1, whereas phase delay is driven by the other repressor with a later peak as Per2. Due to the complementary contributions to phase responses, the ratio of light-induced transcription rates between Per1 and Per2 determines the magnitude and direction of phase shifts at each time of day. Specifically, stronger Per1 light induction than Per2 results in a phase response curve (PRC) with a larger phase advance zone than delay zone as observed in rats and hamsters, whereas stronger Per2 induction causes a larger delay zone as observed in mice. Furthermore, the ratio of light-induced transcription rates required for entrainment is determined by the relation between the circadian and light-dark periods. Namely, if the autonomous period of a circadian clock is longer than the light-dark period, a larger light-induced transcription rate of Per1 than Per2 is required for entrainment, and vice versa. In short, the time difference between Per1 and Per2 expression peaks can differentiate their dynamical functions. The resultant complementary contributions to phase responses can determine entrainability of the circadian clock to the light-dark cycle.
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Affiliation(s)
- Koichiro Uriu
- Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Japan
- * E-mail:
| | - Hajime Tei
- Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Japan
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Sharma R, Puckett H, Kemerling M, Parikh M, Sahota P, Thakkar M. Antisense-Induced Downregulation of Clock Genes in the Shell Region of the Nucleus Accumbens Reduces Binge Drinking in Mice. Alcohol Clin Exp Res 2021; 45:530-542. [PMID: 33606281 PMCID: PMC8535763 DOI: 10.1111/acer.14549] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 12/22/2022]
Abstract
INTRODUCTIONS Binge drinking is a deadly pattern of alcohol consumption. Evidence suggests that genetic variation in clock genes is strongly associated with alcohol misuse; however, the neuroanatomical basis for such a relationship is unknown. The shell region of the nucleus accumbens (NAcSh) is well known to play a role in binge drinking. Hence, we examined whether clock genes in the NAcSh regulate binge drinking. METHODS To address this question, 2 experiments were performed on male C57BL/6J mice. In the first experiment, mice exposed to alcohol or sucrose under the 4-day drinking-in-the-dark (DID) paradigm were euthanized at 2 different time points on day 4 [7 hours after light (pre-binge drinking) or dark (post-binge drinking) onset]. The brains were processed for RT-PCR to examine the expression of circadian clock genes (Clock, Per1, and Per2) in the NAcSh and suprachiasmatic nucleus (SCN). In the second experiment, mice were exposed to alcohol, sucrose, or water as described above. On day 4, 1 hour prior to the onset of alcohol exposure, mice were bilaterally infused with either a mixture of circadian clock gene antisense oligodeoxynucleotides (AS-ODNs; antisense group) or nonsense/random ODNs (R-ODNs; control group) through surgically implanted cannulas above the NAcSh. Alcohol/sucrose/water consumption was measured for 4 hours. Blood alcohol concentration was measured to confirm binge drinking. Microinfusion sites were histologically verified using cresyl violet staining. RESULTS As compared to sucrose, mice euthanized post-binge drinking (not pre-binge drinking) on day 4 displayed a greater expression of circadian genes in the NAcSh but not in the SCN. Knockdown of clock genes in the NAcSh caused a significantly lower volume of alcohol to be consumed on day 4 than in the control treatment. No differences were found in sucrose or water consumption. CONCLUSIONS Our results suggest that clock genes in the NAcSh play a crucial role in binge drinking.
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Affiliation(s)
- Rishi Sharma
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology, University of Missouri, Columbia, MO, USA
| | - Hunter Puckett
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology, University of Missouri, Columbia, MO, USA
| | - Micaela Kemerling
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology, University of Missouri, Columbia, MO, USA
| | - Meet Parikh
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology, University of Missouri, Columbia, MO, USA
| | - Pradeep Sahota
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology, University of Missouri, Columbia, MO, USA
| | - Mahesh Thakkar
- Harry S. Truman Memorial Veterans Hospital and Department of Neurology, University of Missouri, Columbia, MO, USA
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Vasopressin in circadian function of SCN. J Biosci 2020. [DOI: 10.1007/s12038-020-00109-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Srikanta SB, Cermakian N. To Ub or not to Ub: Regulation of circadian clocks by ubiquitination and deubiquitination. J Neurochem 2020; 157:11-30. [PMID: 32717140 DOI: 10.1111/jnc.15132] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/10/2020] [Accepted: 07/14/2020] [Indexed: 12/28/2022]
Abstract
Circadian clocks are internal timing systems that enable organisms to adjust their behavioral and physiological rhythms to the daily changes of their environment. These clocks generate self-sustained oscillations at the cellular, tissue, and behavioral level. The rhythm-generating mechanism is based on a gene expression network with a delayed negative feedback loop that causes the transcripts to oscillate with a period of approximately 24 hr. This oscillatory nature of the proteins involved in this network necessitates that they are intrinsically unstable, with a short half-life. Hence, post-translational modifications (PTMs) are important to precisely time the presence, absence, and interactions of these proteins at appropriate times of the day. Ubiquitination and deubiquitination are counter-balancing PTMs which play a key role in this regulatory process. In this review, we take a comprehensive look at the roles played by the processes of ubiquitination and deubiquitination in the clock machinery of the most commonly studied eukaryotic models of the circadian clock: plants, fungi, fruit flies, and mammals. We present the effects exerted by ubiquitinating and deubiquitinating enzymes on the stability, but also the activity, localization, and interactions of clock proteins. Overall, these PTMs have key roles in regulating not only the pace of the circadian clocks but also their response to external cues and their control of cellular functions.
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Affiliation(s)
- Shashank Bangalore Srikanta
- Integrated Program in Neuroscience, McGill University, Montréal, QC, Canada.,Laboratory of Molecular Chronobiology, Douglas Research Centre, Montréal, QC, Canada
| | - Nicolas Cermakian
- Laboratory of Molecular Chronobiology, Douglas Research Centre, Montréal, QC, Canada.,Department of Psychiatry, McGill University, Montréal, QC, Canada
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Ahmed R, Ashimori A, Iwamoto S, Matsui T, Nakahata Y, Bessho Y. Replicative senescent human cells possess altered circadian clocks with a prolonged period and delayed peak-time. Aging (Albany NY) 2020; 11:950-973. [PMID: 30738414 PMCID: PMC6382424 DOI: 10.18632/aging.101794] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 01/24/2019] [Indexed: 01/16/2023]
Abstract
Over the last decade, a wide array of evidence has been accumulated that disruption of circadian clock is prone to cause age-related diseases and premature aging. On the other hand, aging has been identified as one of the risk factors linked to the alteration of circadian clock. These evidences suggest that the processes of aging and circadian clock feedback on each other at the animal level. However, at the cellular level, we recently revealed that the primary fibroblast cells derived from Bmal1-/- mouse embryo, in which circadian clock is completely disrupted, do not demonstrate the acceleration of cellular aging, i.e., cellular senescence. In addition, little is known about the impact of cellular senescence on circadian clock. In this study, we show for the first time that senescent cells possess a longer circadian period with delayed peak-time and that the variability in peak-time is wider in the senescent cells compared to their proliferative counterparts, indicating that senescent cells show alterations of circadian clock. We, furthermore, propose that investigation at cellular level is a powerful and useful approach to dissect molecular mechanisms of aging in the circadian clock.
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Affiliation(s)
- Rezwana Ahmed
- Laboratory of Gene Regulation Research, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Ikoma, Nara 630-0192, Japan
| | - Atsushige Ashimori
- Laboratory of Gene Regulation Research, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Ikoma, Nara 630-0192, Japan
| | - Satoshi Iwamoto
- Laboratory of Gene Regulation Research, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Ikoma, Nara 630-0192, Japan
| | - Takaaki Matsui
- Laboratory of Gene Regulation Research, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Ikoma, Nara 630-0192, Japan
| | - Yasukazu Nakahata
- Laboratory of Gene Regulation Research, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Ikoma, Nara 630-0192, Japan
| | - Yasumasa Bessho
- Laboratory of Gene Regulation Research, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Ikoma, Nara 630-0192, Japan
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Manoogian ENC, Kumar A, Obed D, Bergan J, Bittman EL. Suprachiasmatic function in a circadian period mutant: Duper alters light-induced activation of vasoactive intestinal peptide cells and PERIOD1 immunostaining. Eur J Neurosci 2019; 48:3319-3334. [PMID: 30346078 DOI: 10.1111/ejn.14214] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 09/07/2018] [Accepted: 09/18/2018] [Indexed: 11/28/2022]
Abstract
Mammalian circadian rhythms are entrained by photic stimuli that are relayed by retinal projections to the core of the suprachiasmatic nucleus (SCN). Neuronal activation, as demonstrated by expression of the immediate early gene c-fos, leads to transcription of the core clock gene per1. The duper mutation in hamsters shortens circadian period and amplifies light-induced phase shifts. We performed two experiments to compare the number of c-FOS immunoreactive (ir) and PER1-ir cells, and the intensity of staining, in the SCN of wild-type (WT) and duper hamsters at various intervals after presentation of a 15-min light pulse in the early subjective night. Light-induced c-FOS-ir within 1 hr in the dorsocaudal SCN of duper, but not WT hamsters. In cells that express vasoactive intestinal peptide (VIP), which plays a critical role in synchronization of SCN cellular oscillators, light-induced c-FOS-ir was greater in duper than WT hamsters. After the light pulse, PER1-ir cells were found in more medial portions of the SCN than FOS-ir, and appeared with a longer latency and over a longer time course, in VIP cells of duper than wild-type hamsters. Our results indicate that the duper allele alters SCN function in ways that may contribute to changes in free running period and phase resetting.
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Affiliation(s)
- Emily N C Manoogian
- Program in Neuroscience and Behavior, University of Massachusetts, Amherst, Massachusetts
| | - Ajay Kumar
- Program in Neuroscience and Behavior, University of Massachusetts, Amherst, Massachusetts
| | - Doha Obed
- Department of Biology, University of Massachusetts, Amherst, Massachusetts
| | - Joseph Bergan
- Psychological and Brain Sciences and Program in Neuroscience and Behavior, University of Massachusetts, Amherst, Massachusetts
| | - Eric L Bittman
- Department of Biology, Program in Neuroscience and Behavior, University of Massachusetts, Amherst, Massachusetts
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14
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Ohdo S, Koyanagi S, Matsunaga N. Chronopharmacological strategies focused on chrono-drug discovery. Pharmacol Ther 2019; 202:72-90. [DOI: 10.1016/j.pharmthera.2019.05.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 05/29/2019] [Indexed: 01/21/2023]
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15
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Gladanac B, Jonkman J, Shapiro CM, Brown TJ, Ralph MR, Casper RF, Rahman SA. Removing Short Wavelengths From Polychromatic White Light Attenuates Circadian Phase Resetting in Rats. Front Neurosci 2019; 13:954. [PMID: 31551702 PMCID: PMC6746919 DOI: 10.3389/fnins.2019.00954] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 08/23/2019] [Indexed: 11/13/2022] Open
Abstract
Visible light is the principal stimulus for resetting the mammalian central circadian pacemaker. Circadian phase resetting is most sensitive to short-wavelength (blue) visible light. We examined the effects of removing short-wavelengths < 500 nm from polychromatic white light using optical filters on circadian phase resetting in rats. Under high irradiance conditions, both long- (7 h) and short- (1 h) duration short-wavelength filtered (< 500 nm) light exposure attenuated phase-delay shifts in locomotor activity rhythms by (∼40-50%) as compared to unfiltered light exposure. However, there was no attenuation in phase resetting under low irradiance conditions. Additionally, the reduction in phase-delay shifts corresponded to regionally specific attenuation in molecular markers of pacemaker activation in response to light exposure, including c-FOS, Per1 and Per2. These results demonstrate that removing short-wavelengths from polychromatic white light can attenuate circadian phase resetting in an irradiance dependent manner. These results have important implications for designing and optimizing lighting interventions to enhance circadian adaptation.
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Affiliation(s)
- Bojana Gladanac
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada
| | - James Jonkman
- Advanced Optical Microscopy Facility, University Health Network, Toronto, ON, Canada
| | - Colin M Shapiro
- Department of Psychiatry and Ophthalmology, University of Toronto, Toronto, ON, Canada.,Youthdale Child and Adolescent Sleep Centre, Toronto, ON, Canada
| | - Theodore J Brown
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.,Division of Reproductive Endocrinology and Infertility, University of Toronto, Toronto, ON, Canada
| | - Martin R Ralph
- Department of Psychology, University of Toronto, Toronto, ON, Canada
| | - Robert F Casper
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.,Division of Reproductive Endocrinology and Infertility, University of Toronto, Toronto, ON, Canada
| | - Shadab A Rahman
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA, United States.,Division of Sleep Medicine, Harvard Medical School, Boston, MA, United States
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16
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Moravcová S, Pačesová D, Melkes B, Kyclerová H, Spišská V, Novotný J, Bendová Z. The day/night difference in the circadian clock's response to acute lipopolysaccharide and the rhythmic Stat3 expression in the rat suprachiasmatic nucleus. PLoS One 2018; 13:e0199405. [PMID: 30265676 PMCID: PMC6161871 DOI: 10.1371/journal.pone.0199405] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/17/2018] [Indexed: 12/21/2022] Open
Abstract
The circadian clock in the suprachiasmatic nucleus (SCN) regulates daily rhythms in physiology and behaviour and is an important part of the mammalian homeostatic system. Previously, we have shown that systemic inflammatory stimulation with lipopolysaccharide (LPS) induced the daytime-dependent phosphorylation of STAT3 in the SCN. Here, we demonstrate the LPS-induced Stat3 mRNA expression in the SCN and show also the circadian rhythm in Stat3 expression in the SCN, with high levels during the day. Moreover, we examined the effects of LPS (1mg/kg), applied either during the day or the night, on the rhythm in locomotor activity of male Wistar rats. We observed that recovery of normal locomotor activity patterns took longer when the animals were injected during the night. The clock genes Per1, Per2 and Nr1d1, and phosphorylation of kinases ERK1/2 and GSK3β are sensitive to external cues and function as the molecular entry for external signals into the circadian clockwork. We also studied the immediate changes in these clock genes expressions and the phosphorylation of ERK1/2 and GSK3β in the suprachiasmatic nucleus in response to daytime or night-time inflammatory stimulation. We revealed mild and transient changes with respect to the controls. Our data stress the role of STAT3 in the circadian clock response to the LPS and provide further evidence of the interaction between the circadian clock and immune system.
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Affiliation(s)
- Simona Moravcová
- Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
- Department of Sleep Medicine and Chronobiology, National Institute of Mental Health, Klecany, Czech Republic
| | - Dominika Pačesová
- Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
- Department of Sleep Medicine and Chronobiology, National Institute of Mental Health, Klecany, Czech Republic
| | - Barbora Melkes
- Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Hana Kyclerová
- Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Veronika Spišská
- Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jiří Novotný
- Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Zdenka Bendová
- Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
- Department of Sleep Medicine and Chronobiology, National Institute of Mental Health, Klecany, Czech Republic
- * E-mail:
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17
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Mifsud KR, Reul JMHM. Mineralocorticoid and glucocorticoid receptor-mediated control of genomic responses to stress in the brain. Stress 2018; 21:389-402. [PMID: 29614900 DOI: 10.1080/10253890.2018.1456526] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Successful coping with stressful events involves adaptive and cognitive processes in the brain that make the individual more resilient to similar stressors in the future. Stressful events result in the secretion of glucocorticoids (GCs) from the adrenal glands into the blood stream. Early work proved instrumental for developing the concept that these hormones act in the brain to coordinate physiological and behavioral responses to stress through binding to two different GC-binding receptors. Once activated these receptors translocate to the nucleus where they act on target genes to facilitate (or sometimes inhibit) transcription. There are two types of receptors in the brain, the mineralocorticoid receptor (MR), and glucocorticoid receptor (GR). This review summarizes recent work which provides new insights regarding the genomic action of these receptors, both under baseline conditions and following exposure to acute stress. This work is discussed alongside the extensive studies undertaken in this field previously and new, and exciting "big data" studies which have generated a wealth of relevant data. The consequence of these new insights will challenge existing assumptions about the role of MRs and GRs and pave the way for the implementation of novel and improved methodologies to identify the role these corticosteroid receptors have in stress-related behavioral adaptation.
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Affiliation(s)
- Karen R Mifsud
- a Neuro-Epigenetics Research Group, Bristol Medical School , University of Bristol , Bristol , UK
| | - Johannes M H M Reul
- a Neuro-Epigenetics Research Group, Bristol Medical School , University of Bristol , Bristol , UK
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18
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Mogi A, Yomoda R, Kimura S, Tsushima C, Takouda J, Sawauchi M, Maekawa T, Ohta H, Nishino S, Kurita M, Mano N, Osumi N, Moriya T. Entrainment of the Circadian Clock in Neural Stem Cells by Epidermal Growth Factor is Closely Associated with ERK1/2-mediated Induction of Multiple Clock-related Genes. Neuroscience 2018. [DOI: 10.1016/j.neuroscience.2018.02.045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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19
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Heyde I, Kiehn JT, Oster H. Mutual influence of sleep and circadian clocks on physiology and cognition. Free Radic Biol Med 2018; 119:8-16. [PMID: 29132973 DOI: 10.1016/j.freeradbiomed.2017.11.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Revised: 11/02/2017] [Accepted: 11/04/2017] [Indexed: 12/11/2022]
Abstract
The 24-h sleep-wake cycle is one of the most prominent outputs of the circadian clock system. At the same time, changes in sleep-wake behavior feedback on behavioral and physiological circadian rhythms, thus altering the coordination of the body's clock network. Sleep and circadian rhythm disruption have similar physiological endpoints including metabolic, cognitive, and immunologic impairments. This raises the question to which extent these phenomena are causally linked. In this review, we summarize different physiologic outcomes of sleep deprivation and mistimed sleep and discuss the experimental evidence for a mediating role of the circadian clock machinery in this context.
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Affiliation(s)
- Isabel Heyde
- Institute of Neurobiology, University of Lübeck, Germany
| | | | - Henrik Oster
- Institute of Neurobiology, University of Lübeck, Germany.
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20
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Wheaton K, Aten S, Queiroz LS, Sullivan K, Oberdick J, Hoyt KR, Obrietan K. Circadian expression and functional characterization of PEA-15 within the mouse suprachiasmatic nucleus. Eur J Neurosci 2018; 47:845-857. [PMID: 29383758 DOI: 10.1111/ejn.13850] [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: 10/30/2017] [Revised: 12/15/2017] [Accepted: 01/15/2018] [Indexed: 12/14/2022]
Abstract
The circadian timing system influences the functional properties of most, if not all, physiological processes. Central to the mammalian timing system is the suprachiasmatic nucleus (SCN) of the hypothalamus. The SCN functions as a 'master clock' that sets the phasing of ancillary circadian oscillator populations found throughout the body. Further, via an entraining input from the retina, the SCN ensures that the clock oscillators are synchronized to the daily light/dark cycle. A critical component of the SCN timing and entrainment systems is the p44/42 mitogen-activated protein kinase (ERK/MAPK) pathway. Here, we examined the expression and function of phosphoprotein-enriched in astrocytes (PEA-15), an ERK scaffold protein that serves as a key regulator of MAPK signaling. A combination of immunolabeling and Western blotting approaches revealed high levels of PEA-15 within the SCN. PEA-15 expression was enriched in distinct subpopulations of SCN neurons, including arginine vasopressin (AVP)-positive neurons of the SCN shell region. Further, expression profiling detected a significant circadian oscillation in PEA-15 expression within the SCN. Brief photic stimulation during the early subjective night led to a significant increase in PEA-15 phosphorylation, an event that can trigger ERK/PEA-15 dissociation. Consistent with this, co-immunoprecipitation assays revealed that PEA-15 is directly bound to ERK in the SCN and that photic stimulation leads to their dissociation. Finally, we show that PEA-15 regulates ERK/MAPK-dependent activation of the core clock gene period1. Together, these data raise the prospect that PEA-15 functions as a key regulator of the SCN timing system.
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Affiliation(s)
- Kelin Wheaton
- Division of Pharmacology, Ohio State University, Columbus, OH, 43210, USA
| | - Sydney Aten
- Department of Neuroscience, Ohio State University, Columbus, OH, 43210, USA
| | | | - Kyle Sullivan
- Department of Neuroscience, Ohio State University, Columbus, OH, 43210, USA
| | - John Oberdick
- Department of Neuroscience, Ohio State University, Columbus, OH, 43210, USA
| | - Kari R Hoyt
- Division of Pharmacology, Ohio State University, Columbus, OH, 43210, USA
| | - Karl Obrietan
- Department of Neuroscience, Ohio State University, Columbus, OH, 43210, USA
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21
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Riedel CS, Georg B, Jørgensen HL, Hannibal J, Fahrenkrug J. Mice Lacking EGR1 Have Impaired Clock Gene (BMAL1) Oscillation, Locomotor Activity, and Body Temperature. J Mol Neurosci 2018; 64:9-19. [PMID: 29138967 DOI: 10.1007/s12031-017-0996-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/02/2017] [Indexed: 11/26/2022]
Abstract
Early growth response transcription factor 1 (EGR1) is expressed in the suprachiasmatic nucleus (SCN) after light stimulation. We used EGR1-deficient mice to address the role of EGR1 in the clock function and light-induced resetting of the clock. The diurnal rhythms of expression of the clock genes BMAL1 and PER1 in the SCN were evaluated by semi-quantitative in situ hybridization. We found no difference in the expression of PER1 mRNA between wildtype and EGR1-deficient mice; however, the daily rhythm of BMAL1 mRNA was completely abolished in the EGR1-deficient mice. In addition, we evaluated the circadian running wheel activity, telemetric locomotor activity, and core body temperature of the mice. Loss of EGR1 neither altered light-induced phase shifts at subjective night nor affected negative masking. Overall, circadian light entrainment was found in EGR1-deficient mice but they displayed a reduced locomotor activity and an altered temperature regulation compared to wild type mice. When placed in running wheels, a subpopulation of EGR1-deficient mice displayed a more disrupted activity rhythm with no measurable endogenous period length (tau). In conclusion, the present study provides the first evidence that the circadian clock in the SCN is disturbed in mice deficient of EGR1.
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Affiliation(s)
- Casper Schwartz Riedel
- Department of Clinical Biochemistry, Bispebjerg and Frederiksberg Hospital, Faculty of Health Sciences, University of Copenhagen, Copenhagen, NV, Denmark.
| | - Birgitte Georg
- Department of Clinical Biochemistry, Bispebjerg and Frederiksberg Hospital, Faculty of Health Sciences, University of Copenhagen, Copenhagen, NV, Denmark
| | - Henrik L Jørgensen
- Department of Clinical Biochemistry, Bispebjerg and Frederiksberg Hospital, Faculty of Health Sciences, University of Copenhagen, Copenhagen, NV, Denmark
| | - Jens Hannibal
- Department of Clinical Biochemistry, Bispebjerg and Frederiksberg Hospital, Faculty of Health Sciences, University of Copenhagen, Copenhagen, NV, Denmark
| | - Jan Fahrenkrug
- Department of Clinical Biochemistry, Bispebjerg and Frederiksberg Hospital, Faculty of Health Sciences, University of Copenhagen, Copenhagen, NV, Denmark
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22
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Koinuma S, Kori H, Tokuda IT, Yagita K, Shigeyoshi Y. Transition of phase response properties and singularity in the circadian limit cycle of cultured cells. PLoS One 2017; 12:e0181223. [PMID: 28715496 PMCID: PMC5513448 DOI: 10.1371/journal.pone.0181223] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Accepted: 06/28/2017] [Indexed: 11/21/2022] Open
Abstract
The circadian system has been regarded as a limit cycle oscillator constructed by the integrated interaction of clock genes and proteins. Here, we investigated a mammalian circadian oscillation geometrically before and after a perturbation. We detected the singular point and transition from a type 1 to type 0 phase response curve (PRC) and determined the embedding dimension to show how many variables are needed to describe the limit cycle oscillation and relaxation process after a perturbation. As a perturbation, forskolin (FK) was administered to Rat-1 cells expressing the Per2::luc gene. By broadly and finely changing the phase and strength of the perturbation, we detected the transition of the PRC from type 1 to type 0 and a possible singular transition point, the property of which agreed quite well with our numerical simulation of the noisy Goodwin model, a simple yet canonical model for the transcription-translation feedback loop of the core clock genes. Furthermore, we estimated the embedding dimension of the limit cycle before and after the perturbation. The trajectory of the limit cycle was embedded in two dimensions but with the perturbation of the state point moved out of the trajectory, the relaxation process was generally embedded in higher dimensions. The average number of embedding dimensions at each dose of FK increased as the FK dose increased but most of the relaxation process was generally embedded within four dimensions. These findings support the existence of a circadian limit cycle oscillator in mammalian cells and suggest that a small number of variables determine the relaxation process after a perturbation.
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Affiliation(s)
- Satoshi Koinuma
- Department of Anatomy and Neurobiology, Kindai University Faculty of Medicine, Osakasayama, Osaka, Japan
- * E-mail: (SK); (YS)
| | - Hiroshi Kori
- Department of Information Sciences, Ochanomizu University, Bunkyo-ku, Tokyo, Japan
| | - Isao T. Tokuda
- Department of Mechanical Engineering, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Kazuhiro Yagita
- Department of Neuroscience and Cell Biology, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto, Japan
| | - Yasufumi Shigeyoshi
- Department of Anatomy and Neurobiology, Kindai University Faculty of Medicine, Osakasayama, Osaka, Japan
- * E-mail: (SK); (YS)
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23
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Kiessling S, O'Callaghan EK, Freyburger M, Cermakian N, Mongrain V. The cell adhesion molecule EphA4 is involved in circadian clock functions. GENES BRAIN AND BEHAVIOR 2017; 17:82-92. [PMID: 28425198 DOI: 10.1111/gbb.12387] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 04/11/2017] [Accepted: 04/11/2017] [Indexed: 12/29/2022]
Abstract
Circadian (∼24 h) rhythms of cellular network plasticity in the central circadian clock, the suprachiasmatic nucleus (SCN), have been described. The neuronal network in the SCN regulates photic resetting of the circadian clock as well as stability of the circadian system during both entrained and constant conditions. EphA4, a cell adhesion molecule regulating synaptic plasticity by controlling connections of neurons and astrocytes, is expressed in the SCN. To address whether EphA4 plays a role in circadian photoreception and influences the neuronal network of the SCN, we have analyzed circadian wheel-running behavior of EphA4 knockout (EphA4-/- ) mice under different light conditions and upon photic resetting, as well as their light-induced protein response in the SCN. EphA4-/- mice exhibited reduced wheel-running activity, longer endogenous periods under constant darkness and shorter periods under constant light conditions, suggesting an effect of EphA4 on SCN function. Moreover, EphA4-/- mice exhibited suppressed phase delays of their wheel-running activity following a light pulse during the beginning of the subjective night (CT15). Accordingly, light-induced c-FOS (FBJ murine osteosarcoma viral oncogene homolog) expression was diminished. Our results suggest a circadian role for EphA4 in the SCN neuronal network, affecting the circadian system and contributing to the circadian response to light.
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Affiliation(s)
- S Kiessling
- Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada.,Present address: Nutrition and Immunology, Technical University of Munich, Freising, Germany
| | - E 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
| | - M Freyburger
- 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
| | - N Cermakian
- Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada
| | - V 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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24
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Dardente H, Wyse CA, Lincoln GA, Wagner GC, Hazlerigg DG. Effects of Photoperiod Extension on Clock Gene and Neuropeptide RNA Expression in the SCN of the Soay Sheep. PLoS One 2016; 11:e0159201. [PMID: 27458725 PMCID: PMC4961288 DOI: 10.1371/journal.pone.0159201] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 06/28/2016] [Indexed: 01/23/2023] Open
Abstract
In mammals, changing daylength (photoperiod) is the main synchronizer of seasonal functions. The photoperiodic information is transmitted through the retino-hypothalamic tract to the suprachiasmatic nuclei (SCN), site of the master circadian clock. To investigate effects of day length change on the sheep SCN, we used in-situ hybridization to assess the daily temporal organization of expression of circadian clock genes (Per1, Per2, Bmal1 and Fbxl21) and neuropeptides (Vip, Grp and Avp) in animals acclimated to a short photoperiod (SP; 8h of light) and at 3 or 15 days following transfer to a long photoperiod (LP3, LP15, respectively; 16h of light), achieved by an acute 8-h delay of lights off. We found that waveforms of SCN gene expression conformed to those previously seen in LP acclimated animals within 3 days of transfer to LP. Mean levels of expression for Per1-2 and Fbxl21 were nearly 2-fold higher in the LP15 than in the SP group. The expression of Vip was arrhythmic and unaffected by photoperiod, while, in contrast to rodents, Grp expression was not detectable within the sheep SCN. Expression of the circadian output gene Avp cycled robustly in all photoperiod groups with no detectable change in phasing. Overall these data suggest that synchronizing effects of light on SCN circadian organisation proceed similarly in ungulates and in rodents, despite differences in neuropeptide gene expression.
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Affiliation(s)
- Hugues Dardente
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
- Institute of Biological and Environmental Sciences, Zoology Building, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 2TZ, United Kingdom
- * E-mail: (DGH); (HD)
| | - Cathy A. Wyse
- Institute of Biological and Environmental Sciences, Zoology Building, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 2TZ, United Kingdom
- Veterinary school, Bearsden Road, Glasgow, G61 1QH, United Kingdom
| | - Gerald A. Lincoln
- Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4SB, United Kingdom
| | - Gabriela C. Wagner
- Institute of Biological and Environmental Sciences, Zoology Building, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 2TZ, United Kingdom
- Department of Arctic and Marine Biology, Faculty of BioSciences, Fisheries and Economy, University of Tromsø, 9037, Tromsø, Norway
| | - David G. Hazlerigg
- Institute of Biological and Environmental Sciences, Zoology Building, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 2TZ, United Kingdom
- Department of Arctic and Marine Biology, Faculty of BioSciences, Fisheries and Economy, University of Tromsø, 9037, Tromsø, Norway
- * E-mail: (DGH); (HD)
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25
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Melatonin Signal Transduction Pathways Require E-Box-Mediated Transcription of Per1 and Per2 to Reset the SCN Clock at Dusk. PLoS One 2016; 11:e0157824. [PMID: 27362940 PMCID: PMC4928778 DOI: 10.1371/journal.pone.0157824] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Accepted: 06/06/2016] [Indexed: 12/12/2022] Open
Abstract
Melatonin is released from the pineal gland into the circulatory system at night in the absence of light, acting as “hormone of darkness” to the brain and body. Melatonin also can regulate circadian phasing of the suprachiasmatic nucleus (SCN). During the day-to-night transition, melatonin exposure advances intrinsic SCN neural activity rhythms via the melatonin type-2 (MT2) receptor and downstream activation of protein kinase C (PKC). The effects of melatonin on SCN phasing have not been linked to daily changes in the expression of core genes that constitute the molecular framework of the circadian clock. Using real-time RT-PCR, we found that melatonin induces an increase in the expression of two clock genes, Period 1 (Per1) and Period 2 (Per2). This effect occurs at CT 10, when melatonin advances SCN phase, but not at CT 6, when it does not. Using anti-sense oligodeoxynucleotides (α ODNs) to Per 1 and Per 2, as well as to E-box enhancer sequences in the promoters of these genes, we show that their specific induction is necessary for the phase-altering effects of melatonin on SCN neural activity rhythms in the rat. These effects of melatonin on Per1 and Per2 were mediated by PKC. This is unlike day-active non-photic signals that reset the SCN clock by non-PCK signal transduction mechanisms and by decreasing Per1 expression. Rather, this finding extends roles for Per1 and Per2, which are critical to photic phase-resetting, to a nonphotic zeitgeber, melatonin, and suggest that the regulation of these clock gene transcripts is required for clock resetting by diverse regulatory cues.
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26
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Hastings MH, Herzog ED. Clock Genes, Oscillators, and Cellular Networks in the Suprachiasmatic Nuclei. J Biol Rhythms 2016; 19:400-13. [PMID: 15534320 DOI: 10.1177/0748730404268786] [Citation(s) in RCA: 186] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The mammalian SCN contains a biological clock that drives remarkably precise circadian rhythms in vivo and in vitro. Recent advances have revealed molecular and cellular mechanisms required for the generation of these daily rhythms and their synchronization between SCN neurons and to the environmental light cycle. This review of the evidence for a cell-autonomous circadian pacemaker within specialized neurons of the SCN focuses on 6 genes implicated within the pace making mechanism, an additional 4 genes implicated in pathways from the pacemaker, and the intercellular and intracellular mechanisms that synchronize SCN neurons to each other and to solar time.
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Affiliation(s)
- Michael H Hastings
- MRC Laboratory of Molecular Biology, Division of Neurobiology, Cambridge, UK.
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A tunable artificial circadian clock in clock-defective mice. Nat Commun 2015; 6:8587. [PMID: 26617050 PMCID: PMC4674671 DOI: 10.1038/ncomms9587] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 09/09/2015] [Indexed: 12/17/2022] Open
Abstract
Self-sustaining oscillations are essential for diverse physiological functions such as the cell cycle, insulin secretion and circadian rhythms. Synthetic oscillators using biochemical feedback circuits have been generated in cell culture. These synthetic systems provide important insight into design principles for biological oscillators, but have limited similarity to physiological pathways. Here we report the generation of an artificial, mammalian circadian clock in vivo, capable of generating robust, tunable circadian rhythms. In mice deficient in Per1 and Per2 genes (thus lacking circadian rhythms), we artificially generate PER2 rhythms and restore circadian sleep/wake cycles with an inducible Per2 transgene. Our artificial clock is tunable as the period and phase of the rhythms can be modulated predictably. This feature, and other design principles of our work, might enhance the study and treatment of circadian dysfunction and broader aspects of physiology involving biological oscillators. Circadian rhythms are central to health and disease and there is renewed interest in chronotherapy. Here, the authors present a mouse with an artificial circadian clock that can be pharmacologically tuned, providing a tool for future studies of circadian biology and therapy.
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Kudo T, Block GD, Colwell CS. The Circadian Clock Gene Period1 Connects the Molecular Clock to Neural Activity in the Suprachiasmatic Nucleus. ASN Neuro 2015; 7:7/6/1759091415610761. [PMID: 26553726 PMCID: PMC4710129 DOI: 10.1177/1759091415610761] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The neural activity patterns of suprachiasmatic nucleus (SCN) neurons are dynamically regulated throughout the circadian cycle with highest levels of spontaneous action potentials during the day. These rhythms in electrical activity are critical for the function of the circadian timing system and yet the mechanisms by which the molecular clockwork drives changes in the membrane are not well understood. In this study, we sought to examine how the clock gene Period1 (Per1) regulates the electrical activity in the mouse SCN by transiently and selectively decreasing levels of PER1 through use of an antisense oligodeoxynucleotide. We found that this treatment effectively reduced SCN neural activity. Direct current injection to restore the normal membrane potential partially, but not completely, returned firing rate to normal levels. The antisense treatment also reduced baseline [Ca2+]i levels as measured by Fura2 imaging technique. Whole cell patch clamp recording techniques were used to examine which specific potassium currents were altered by the treatment. These recordings revealed that the large conductance [Ca2+]i-activated potassium currents were reduced in antisense-treated neurons and that blocking this current mimicked the effects of the anti-sense on SCN firing rate. These results indicate that the circadian clock gene Per1 alters firing rate in SCN neurons and raise the possibility that the large conductance [Ca2+]i-activated channel is one of the targets.
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Affiliation(s)
- Takashi Kudo
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA, USA
| | - Gene D Block
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA, USA
| | - Christopher S Colwell
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA, USA
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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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Pačesová D, Volfová B, Červená K, Hejnová L, Novotný J, Bendová Z. Acute morphine affects the rat circadian clock via rhythms of phosphorylated ERK1/2 and GSK3β kinases and Per1 expression in the rat suprachiasmatic nucleus. Br J Pharmacol 2015; 172:3638-49. [PMID: 25828914 DOI: 10.1111/bph.13152] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 03/04/2015] [Accepted: 03/26/2015] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND AND PURPOSE Opioids affect the circadian clock and may change the timing of many physiological processes. This study was undertaken to investigate the daily changes in sensitivity of the circadian pacemaker to an analgesic dose of morphine, and to uncover a possible interplay between circadian and opioid signalling. EXPERIMENTAL APPROACH A time-dependent effect of morphine (1 mg·kg(-1) , i.p.) applied either during the day or during the early night was followed, and the levels of phosphorylated ERK1/2, GSK3β, c-Fos and Per genes were assessed by immunohistochemistry and in situ hybridization. The effect of morphine pretreatment on light-induced pERK and c-Fos was examined, and day/night difference in activity of opioid receptors was evaluated by [(35) S]-GTPγS binding assay. KEY RESULTS Morphine stimulated a rise in pERK1/2 and pGSK3β levels in the suprachiasmatic nucleus (SCN) when applied during the day but significantly reduced both kinases when applied during the night. Morphine at night transiently induced Period1 but not Period2 in the SCN and did not attenuate the light-induced level of pERK1/2 and c-Fos in the SCN. The activity of all three principal opioid receptors was high during the day but decreased significantly at night, except for the δ receptor. Finally, we demonstrated daily profiles of pERK1/2 and pGSK3β levels in the rat ventrolateral and dorsomedial SCN. CONCLUSIONS AND IMPLICATIONS Our data suggest that the phase-shifting effect of opioids may be mediated via post-translational modification of clock proteins by means of activated ERK1/2 and GSK3β.
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Affiliation(s)
| | - Barbora Volfová
- Faculty of Science, Charles University, Prague, Czech Republic
| | | | - Lucie Hejnová
- Faculty of Science, Charles University, Prague, Czech Republic
| | - Jiří Novotný
- Faculty of Science, Charles University, Prague, Czech Republic
| | - Zdeňka Bendová
- Faculty of Science, Charles University, Prague, Czech Republic
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31
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Cao R, Gkogkas CG, de Zavalia N, Blum ID, Yanagiya A, Tsukumo Y, Xu H, Lee C, Storch KF, Liu AC, Amir S, Sonenberg N. Light-regulated translational control of circadian behavior by eIF4E phosphorylation. Nat Neurosci 2015; 18:855-62. [PMID: 25915475 PMCID: PMC4446158 DOI: 10.1038/nn.4010] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 03/28/2015] [Indexed: 12/14/2022]
Abstract
The circadian (~24 h) clock is continuously entrained (reset) by ambient light so that endogenous rhythms are synchronized with daily changes in the environment. Light-induced gene expression is thought to be the molecular mechanism underlying clock entrainment. mRNA translation is a key step of gene expression, but how clock entrainment is controlled at the mRNA translation level is not understood. Here we report that a light- and circadian clock-regulated MAPK/MNK pathway leads to phosphorylation of the cap-binding protein eIF4E in the mouse suprachiasmatic nucleus (SCN) of the hypothalamus, the locus of the master circadian clock in mammals. Phosphorylation of eIF4E specifically promotes translation of Period (Per) 1 and 2 mRNAs and increases the abundance of basal and inducible PER proteins, which facilitates circadian clock resetting and precise timekeeping. Together, these results highlight a critical role for light-regulated translational control in the physiology of the circadian clock.
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Affiliation(s)
- Ruifeng Cao
- Department of Biochemistry and Goodman Cancer Research Center, McGill University, Montreal, Canada
| | - Christos G Gkogkas
- Patrick Wild Centre, Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
| | - Nuria de Zavalia
- Center for Studies in Behavioral Neurobiology, Concordia University, Montreal, Canada
| | - Ian D Blum
- Douglas Mental Health University Institute and Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Akiko Yanagiya
- Department of Biochemistry and Goodman Cancer Research Center, McGill University, Montreal, Canada
| | - Yoshinori Tsukumo
- Department of Biochemistry and Goodman Cancer Research Center, McGill University, Montreal, Canada
| | - Haiyan Xu
- Department of Biological Sciences, University of Memphis, Memphis, Tennessee, USA
| | - Choogon Lee
- Department of Biomedical Sciences, Neuroscience Program, College of Medicine, Florida State University, Tallahassee, Florida, USA
| | - Kai-Florian Storch
- Douglas Mental Health University Institute and Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Andrew C Liu
- Department of Biological Sciences, University of Memphis, Memphis, Tennessee, USA
| | - Shimon Amir
- Center for Studies in Behavioral Neurobiology, Concordia University, Montreal, Canada
| | - Nahum Sonenberg
- Department of Biochemistry and Goodman Cancer Research Center, McGill University, Montreal, Canada
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32
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Ramkisoensing A, Gu C, van Engeldorp Gastelaars HMD, Michel S, Deboer T, Rohling JHT, Meijer JH. Enhanced phase resetting in the synchronized suprachiasmatic nucleus network. J Biol Rhythms 2014; 29:4-15. [PMID: 24492878 DOI: 10.1177/0748730413516750] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The suprachiasmatic nucleus (SCN) adapts to both the external light-dark (LD) cycle and seasonal changes in day length. In short photoperiods, single-cell activity patterns are tightly synchronized (i.e., in phase); in long photoperiods, these patterns are relatively dispersed, causing lower amplitude rhythms. The limit cycle oscillator has been used to describe the SCN's circadian rhythmicity and predicts that following a given perturbation, high-amplitude SCN rhythms will shift less than low-amplitude rhythms. Some studies reported, however, that phase delays are larger when animals are entrained to a short photoperiod. Because phase advances and delays are mediated by partially distinct (i.e., nonoverlapping) biochemical pathways, we investigated the effect of a 4-h phase advance of the LD cycle in mice housed in either short (LD 8:16) or long (LD 16:8) photoperiods. In vitro recordings revealed a significantly larger phase advance in the SCN of mice entrained to short as compared to long photoperiods (4.2 ± 0.3 h v. 1.4 ± 0.9 h, respectively). Surprisingly, in mice with long photoperiods, the behavioral phase shift was larger than the phase shift of the SCN (3.7 ± 0.4 h v. 1.4 ± 0.9 h, respectively). To exclude a confounding influence of running-wheel activity on the magnitude of the shifts of the SCN, we repeated the experiments in the absence of running wheels and found similar shifts in the SCN in vitro in short and long days (3.0 ± 0.5 h v. 0.4 ± 0.9 h, respectively). Interestingly, removal of the running wheel reduced the phase-shifting capacity of mice in long days, leading to similar behavioral shifts in short and long photoperiods (1.0 ± 0.1 h v. 1.0 ± 0.4 h). As the behavioral shifts in the presence of wheels were larger than the shift of the SCN, it is suggested that additional, non-SCN neuronal networks in the brain are involved in regulating the timing of behavioral activity. On the basis of the phase shifts observed in vitro, we conclude that highly synchronized SCN networks with high-amplitude rhythms show a larger phase-shifting capacity than desynchronized networks of low amplitude.
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Affiliation(s)
- Ashna Ramkisoensing
- Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, the Netherlands
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33
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Rhythmic U2af26 Alternative Splicing Controls PERIOD1 Stability and the Circadian Clock in Mice. Mol Cell 2014; 54:651-62. [DOI: 10.1016/j.molcel.2014.04.015] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 02/24/2014] [Accepted: 04/09/2014] [Indexed: 11/23/2022]
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McMahon DG, Iuvone PM, Tosini G. Circadian organization of the mammalian retina: from gene regulation to physiology and diseases. Prog Retin Eye Res 2013; 39:58-76. [PMID: 24333669 DOI: 10.1016/j.preteyeres.2013.12.001] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 11/27/2013] [Accepted: 12/01/2013] [Indexed: 01/27/2023]
Abstract
The retinal circadian system represents a unique structure. It contains a complete circadian system and thus the retina represents an ideal model to study fundamental questions of how neural circadian systems are organized and what signaling pathways are used to maintain synchrony of the different structures in the system. In addition, several studies have shown that multiple sites within the retina are capable of generating circadian oscillations. The strength of circadian clock gene expression and the emphasis of rhythmic expression are divergent across vertebrate retinas, with photoreceptors as the primary locus of rhythm generation in amphibians, while in mammals clock activity is most robust in the inner nuclear layer. Melatonin and dopamine serve as signaling molecules to entrain circadian rhythms in the retina and also in other ocular structures. Recent studies have also suggested GABA as an important component of the system that regulates retinal circadian rhythms. These transmitter-driven influences on clock molecules apparently reinforce the autonomous transcription-translation cycling of clock genes. The molecular organization of the retinal clock is similar to what has been reported for the SCN although inter-neural communication among retinal neurons that form the circadian network is apparently weaker than those present in the SCN, and it is more sensitive to genetic disruption than the central brain clock. The melatonin-dopamine system is the signaling pathway that allows the retinal circadian clock to reconfigure retinal circuits to enhance light-adapted cone-mediated visual function during the day and dark-adapted rod-mediated visual signaling at night. Additionally, the retinal circadian clock also controls circadian rhythms in disk shedding and phagocytosis, and possibly intraocular pressure. Emerging experimental data also indicate that circadian clock is also implicated in the pathogenesis of eye disease and compelling experimental data indicate that dysfunction of the retinal circadian system negatively impacts the retina and possibly the cornea and the lens.
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Affiliation(s)
- Douglas G McMahon
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA; Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Gianluca Tosini
- Neuroscience Institute and Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, 30310 GA, USA.
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35
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Baidanoff FM, Plano SA, Doctorovich F, Suárez SA, Golombek DA, Chiesa JJ. N-nitrosomelatonin enhances photic synchronization of mammalian circadian rhythms. J Neurochem 2013; 129:60-71. [PMID: 24261470 DOI: 10.1111/jnc.12613] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 11/12/2013] [Accepted: 11/19/2013] [Indexed: 12/18/2022]
Abstract
Most physiological processes in mammals are synchronized to the daily light:dark cycle by a circadian clock located in the hypothalamic suprachiasmatic nucleus. Signal transduction of light-induced phase advances of the clock is mediated through a neuronal nitric oxide synthase-guanilyl cyclase pathway. We have employed a novel nitric oxide-donor, N-nitrosomelatonin, to enhance the photic synchronization of circadian rhythms in hamsters. The intraperitoneal administration of this drug before a sub-saturating light pulse at circadian time 18 generated a twofold increase of locomotor rhythm phase-advances, having no effect over saturating light pulses. This potentiation was also obtained even when inhibiting suprachiasmatic nitric oxide synthase activity. However, N-nitrosomelatonin had no effect on light-induced phase delays at circadian time 14. The photic-enhancing effects were correlated with an increased suprachiasmatic immunoreactivity of FBJ murine osteosarcoma viral oncogene and period1. Moreover, in vivo nitric oxide release by N-nitrosomelatonin was verified by measuring nitrate and nitrite levels in suprachiasmatic nuclei homogenates. The compound also accelerated resynchronization to an abrupt 6-h advance in the light:dark cycle (but not resynchronization to a 6-h delay). Here, we demonstrate the chronobiotic properties of N-nitrosomelatonin, emphasizing the importance of nitric oxide-mediated transduction for circadian phase advances.
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Affiliation(s)
- Fernando M Baidanoff
- Laboratorio de Cronobiología, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes/CONICET, Bernal, Argentina
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36
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An S, Harang R, Meeker K, Granados-Fuentes D, Tsai CA, Mazuski C, Kim J, Doyle FJ, Petzold LR, Herzog ED. A neuropeptide speeds circadian entrainment by reducing intercellular synchrony. Proc Natl Acad Sci U S A 2013; 110:E4355-61. [PMID: 24167276 PMCID: PMC3832006 DOI: 10.1073/pnas.1307088110] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Shift work or transmeridian travel can desynchronize the body's circadian rhythms from local light-dark cycles. The mammalian suprachiasmatic nucleus (SCN) generates and entrains daily rhythms in physiology and behavior. Paradoxically, we found that vasoactive intestinal polypeptide (VIP), a neuropeptide implicated in synchrony among SCN cells, can also desynchronize them. The degree and duration of desynchronization among SCN neurons depended on both the phase and the dose of VIP. A model of the SCN consisting of coupled stochastic cells predicted both the phase- and the dose-dependent response to VIP and that the transient phase desynchronization, or "phase tumbling", could arise from intrinsic, stochastic noise in small populations of key molecules (notably, Period mRNA near its daily minimum). The model also predicted that phase tumbling following brief VIP treatment would accelerate entrainment to shifted environmental cycles. We tested this using a prepulse of VIP during the day before a shift in either a light cycle in vivo or a temperature cycle in vitro. Although VIP during the day does not shift circadian rhythms, the VIP pretreatment approximately halved the time required for mice to reentrain to an 8-h shifted light schedule and for SCN cultures to reentrain to a 10-h shifted temperature cycle. We conclude that VIP below 100 nM synchronizes SCN cells and above 100 nM reduces synchrony in the SCN. We show that exploiting these mechanisms that transiently reduce cellular synchrony before a large shift in the schedule of daily environmental cues has the potential to reduce jet lag.
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Affiliation(s)
- Sungwon An
- Department of Biology, Washington University in St. Louis, Saint Louis, MO 63130
| | - Rich Harang
- Department of Computer Science, University of California, Santa Barbara, CA 93106-3110; and
| | - Kirsten Meeker
- Department of Computer Science, University of California, Santa Barbara, CA 93106-3110; and
| | | | - Connie A. Tsai
- Department of Biology, Washington University in St. Louis, Saint Louis, MO 63130
| | - Cristina Mazuski
- Department of Biology, Washington University in St. Louis, Saint Louis, MO 63130
| | - Jihee Kim
- Department of Biology, Washington University in St. Louis, Saint Louis, MO 63130
| | - Francis J. Doyle
- Department of Chemical Engineering, University of California, Santa Barbara CA 93106-5080
| | - Linda R. Petzold
- Department of Computer Science, University of California, Santa Barbara, CA 93106-3110; and
| | - Erik D. Herzog
- Department of Biology, Washington University in St. Louis, Saint Louis, MO 63130
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37
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Mahoney CE, McKinley Brewer J, Bittman EL. Central control of circadian phase in arousal-promoting neurons. PLoS One 2013; 8:e67173. [PMID: 23826226 PMCID: PMC3691112 DOI: 10.1371/journal.pone.0067173] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Accepted: 05/14/2013] [Indexed: 11/18/2022] Open
Abstract
Cells of the dorsomedial/lateral hypothalamus (DMH/LH) that produce hypocretin (HCRT) promote arousal in part by activation of cells of the locus coeruleus (LC) which express tyrosine hydroxylase (TH). The suprachiasmatic nucleus (SCN) drives endogenous daily rhythms, including those of sleep and wakefulness. These circadian oscillations are generated by a transcriptional-translational feedback loop in which the Period (Per) genes constitute critical components. This cell-autonomous molecular clock operates not only within the SCN but also in neurons of other brain regions. However, the phenotype of such neurons and the nature of the phase controlling signal from the pacemaker are largely unknown. We used dual fluorescent in situ hybridization to assess clock function in vasopressin, HCRT and TH cells of the SCN, DMH/LH and LC, respectively, of male Syrian hamsters. In the first experiment, we found that Per1 expression in HCRT and TH oscillated in animals held in constant darkness with a peak phase that lagged that in AVP cells of the SCN by several hours. In the second experiment, hamsters induced to split their locomotor rhythms by exposure to constant light had asymmetric Per1 expression within cells of the middle SCN at 6 h before activity onset (AO) and in HCRT cells 9 h before and at AO. We did not observe evidence of lateralization of Per1 expression in the LC. We conclude that the SCN communicates circadian phase to HCRT cells via lateralized neural projections, and suggests that Per1 expression in the LC may be regulated by signals of a global or bilateral nature.
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Affiliation(s)
- Carrie E. Mahoney
- Neuroscience and Behavior Program, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Judy McKinley Brewer
- Neuroscience and Behavior Program, University of Massachusetts, Amherst, Massachusetts, United States of America
- Department of Biology, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Eric L. Bittman
- Neuroscience and Behavior Program, University of Massachusetts, Amherst, Massachusetts, United States of America
- Department of Biology, University of Massachusetts, Amherst, Massachusetts, United States of America
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38
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Kudo T, Tahara Y, Gamble KL, McMahon DG, Block GD, Colwell CS. Vasoactive intestinal peptide produces long-lasting changes in neural activity in the suprachiasmatic nucleus. J Neurophysiol 2013; 110:1097-106. [PMID: 23741043 DOI: 10.1152/jn.00114.2013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The neuropeptide vasoactive intestinal peptide (VIP) is expressed at high levels in the neurons of the suprachiasmatic nucleus (SCN). While VIP is known to be important to the input and output pathways from the SCN, the physiological effects of VIP on electrical activity of SCN neurons are not well known. Here the impact of VIP on firing rate of SCN neurons was investigated in mouse slice cultures recorded during the night. The application of VIP produced an increase in electrical activity in SCN slices that lasted several hours after treatment. This is a novel mechanism by which this peptide can produce long-term changes in central nervous system physiology. The increase in action potential frequency was blocked by a VIP receptor antagonist and lost in a VIP receptor knockout mouse. In addition, inhibitors of both the Epac family of cAMP binding proteins and cAMP-dependent protein kinase (PKA) blocked the induction by VIP. The persistent increase in spike rate following VIP application was not seen in SCN neurons from mice deficient in Kv3 channel proteins and was dependent on the clock protein PER1. These findings suggest that VIP regulates the long-term firing rate of SCN neurons through a VIPR2-mediated increase in the cAMP pathway and implicate the fast delayed rectifier (FDR) potassium currents as one of the targets of this regulation.
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Affiliation(s)
- Takashi Kudo
- Laboratory of Circadian and Sleep Medicine, Department of Psychiatry and Biobehavioral Sciences, University of California-Los Angeles, CA 90024, USA
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39
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Xu CX, Wang C, Krager SL, Bottum KM, Tischkau SA. Aryl hydrocarbon receptor activation attenuates Per1 gene induction and influences circadian clock resetting. Toxicol Sci 2013; 132:368-78. [PMID: 23291558 DOI: 10.1093/toxsci/kfs345] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Light-stimulated adjustment of the circadian clock is an important adaptive physiological response that allows maintenance of behavioral synchrony with solar time. Our previous studies indicate that the aryl hydrocarbon receptor (AhR) agonist 2,3,7,8- tetrachlorodibenzo-p-dioxin attenuates light-induced phase resetting in early night. However, the mechanism of inhibition remains unclear. In this study, we showed that another potent AhR agonist-β-naphthoflavone (BNF)-significantly decreased light-induced phase shifts in wild-type (WT) mice, whereas AhR knockout mice had an enhanced response to light that was unaffected by BNF. Mechanistically, BNF blocked light induction of the Per1 transcript in suprachiasmatic nucleus and liver in WT mice, and BNF blocked forskolin (FSK)-induced Per1 transcripts in Hepa-1c1c7 (c7) cells. An E-box decoy did not affect BNF inhibition of FSK-induced Per1 transcripts in c7 cells. cAMP-response element (CRE)-dependent induction of Per1 promoter activity in response to FSK in combination with phorbol 12-tetradecanoate 13-acetate was suppressed in cells that expressed high levels of AhR (c7) compared with cells lacking functional AhR activity (c12). In addition, the inhibitory effect of BNF on FSK-induced Per1 was dependent on phosphorylation of JNK. Together, these results suggest that AhR activation inhibits light-induced phase resetting through the activation of JNK, negative regulation of CREs in the Per1 promoter, and suppression of Per1.
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Affiliation(s)
- Can-Xin Xu
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois 62702, USA
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40
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Montgomery JR, Whitt JP, Wright BN, Lai MH, Meredith AL. Mis-expression of the BK K(+) channel disrupts suprachiasmatic nucleus circuit rhythmicity and alters clock-controlled behavior. Am J Physiol Cell Physiol 2012; 304:C299-311. [PMID: 23174562 DOI: 10.1152/ajpcell.00302.2012] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In mammals, almost all aspects of circadian rhythmicity are attributed to activity in a discrete neural circuit of the hypothalamus, the suprachiasmatic nucleus (SCN). A 24-h rhythm in spontaneous firing is the fundamental neural intermediary to circadian behavior, but the ionic mechanisms that pattern circuit rhythmicity, and the integrated impact on behavior, are not well studied. Here, we demonstrate that daily modulation of a major component of the nighttime-phased suppressive K(+) current, encoded by the BK Ca(2+)-activated K(+) current channel (K(Ca)1.1 or Kcnma1), is a critical arbiter of circadian rhythmicity in the SCN circuit. Aberrant induction of BK current during the day in transgenic mice using a Per1 promoter (Tg-BK(R207Q)) reduced SCN firing or silenced neurons, decreasing the circadian amplitude of the ensemble circuit rhythm. Changes in cellular and circuit excitability in Tg-BK(R207Q) SCNs were correlated with elongated behavioral active periods and enhanced responses to phase-shifting stimuli. Unexpectedly, despite the severe reduction in circuit amplitude, circadian behavioral amplitudes in Tg-BK(R207Q) mice were relatively normal. These data demonstrate that downregulation of the BK current during the day is essential for the high amplitude neural activity pattern in the SCN that restricts locomotor activity to the appropriate phase and maintains the clock's robustness against perturbation. However, a residually rhythmic subset prevails over the ensemble circuit to drive the fundamental circadian behavioral rhythm.
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Affiliation(s)
- Jenna R Montgomery
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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Cao R, Butcher GQ, Karelina K, Arthur JS, Obrietan K. Mitogen- and stress-activated protein kinase 1 modulates photic entrainment of the suprachiasmatic circadian clock. Eur J Neurosci 2012; 37:130-40. [PMID: 23127194 DOI: 10.1111/ejn.12028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 09/10/2012] [Accepted: 09/20/2012] [Indexed: 11/30/2022]
Abstract
The master circadian clock in mammals, the suprachiasmatic nucleus (SCN), is under the entraining influence of the external light cycle. At a mechanistic level, intracellular signaling via the p42/44 mitogen-activated protein kinase pathway appears to play a central role in light-evoked clock entrainment; however, the precise downstream mechanisms by which this pathway influences clock timing are not known. Within this context, we have previously reported that light stimulates activation of the mitogen-activated protein kinase effector mitogen-stress-activated kinase 1 (MSK1) in the SCN. In this study, we utilised MSK1(-/-) mice to further investigate the potential role of MSK1 in circadian clock timing and entrainment. Locomotor activity analysis revealed that MSK1 null mice entrained to a 12 h light/dark cycle and exhibited circadian free-running rhythms in constant darkness. Interestingly, the free-running period in MSK1 null mice was significantly longer than in wild-type control animals, and MSK1 null mice exhibited a significantly greater variance in activity onset. Further, MSK1 null mice exhibited a significant reduction in the phase-delaying response to an early night light pulse (100 lux, 15 min), and, using an 8 h phase-advancing 'jet-lag' experimental paradigm, MSK1 knockout animals exhibited a significantly delayed rate of re-entrainment. At the molecular level, early night light-evoked cAMP response element-binding protein (CREB) phosphorylation, histone phosphorylation and Period1 gene expression were markedly attenuated in MSK1(-/-) animals relative to wild-type mice. Together, these data provide key new insights into the molecular mechanisms by which MSK1 affects the SCN clock.
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Affiliation(s)
- Ruifeng Cao
- Department of Neuroscience, Ohio State University, Columbus, OH, USA
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Granados-Fuentes D, Herzog ED. The clock shop: coupled circadian oscillators. Exp Neurol 2012; 243:21-7. [PMID: 23099412 DOI: 10.1016/j.expneurol.2012.10.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 09/04/2012] [Accepted: 10/16/2012] [Indexed: 01/10/2023]
Abstract
Daily rhythms in neural activity underlie circadian rhythms in sleep-wake and other daily behaviors. The cells within the mammalian suprachiasmatic nucleus (SCN) are intrinsically capable of 24-h timekeeping. These cells synchronize with each other and with local environmental cycles to drive coherent rhythms in daily behaviors. Recent studies have identified a small number of neuropeptides critical for this ability to synchronize and sustain coordinated daily rhythms. This review highlights the roles of specific intracellular and intercellular signals within the SCN that underlie circadian synchrony.
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Seo DH, Kim HS, Ko CY, Schreiber J, Jang YS, Bae K. The effects of circadian disturbances induced by night shifts on the mouse peripheral tissues. Anim Cells Syst (Seoul) 2012. [DOI: 10.1080/19768354.2012.706639] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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Abstract
Masking is an acute effect of an external signal on an overt rhythm and is distinct from the process of entrainment. In the current study, we investigated the phase dependence and molecular mechanisms regulating masking effects of light pulses on spontaneous locomotor activity in mice. The circadian genes, Period1 (Per1) and Per2, are necessary components of the timekeeping machinery and entrainment by light appears to involve the induction of the expression of Per1 and Per2 mRNAs in the suprachiasmatic nuclei (SCN). We assessed the roles of the Per genes in regulating masking by assessing the effects of light pulses on nocturnal locomotor activity in C57BL/6J Per mutant mice. We found that Per1(-/-) and Per2(-/-) mice had robust negative masking responses to light. In addition, the locomotor activity of Per1(-/-)/Per2(-/-) mice appeared to be rhythmic in the light-dark (LD) cycle, and the phase of activity onset was advanced (but varied among individual mice) relative to lights off. This rhythm persisted for 1 to 2 days in constant darkness in some Per1(-/-)/Per2(-/-) mice. Furthermore, Per1(-/-)/Per2(-/-) mice exhibited robust negative masking responses to light. Negative masking was phase dependent in wild-type mice such that maximal suppression was induced by light pulses at zeitgeber time 14 (ZT14) and gradually weaker suppression occurred during light pulses at ZT16 and ZT18. By measuring the phase shifts induced by the masking protocol (light pulses were administered to mice maintained in the LD cycle), we found that the phase responsiveness of Per mutant mice was altered compared to wild-types. Together, our data suggest that negative masking responses to light are robust in Per mutant mice and that the Per1(-/-)/Per2(-/-) SCN may be a light-driven, weak/damping oscillator.
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Affiliation(s)
- Julie S Pendergast
- Department of Biological Sciences, Vanderbilt University , Nashville, Tennessee 37235, USA
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Kozaki T, Toda N, Noguchi H, Yasukouchi A. Effects of different light intensities in the morning on dim light melatonin onset. J Physiol Anthropol 2011; 30:97-102. [PMID: 21636952 DOI: 10.2114/jpa2.30.97] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
The present study evaluated the effects of exposure to light intensity in the morning on dim light melatonin onset (DLMO). The tested light intensities were 750 lux, 150 lux, 3000 lux, 6000 lux and 12,000 lux (horizontal illuminance at cornea), using commercial 5000 K fluorescent lamps. Eleven healthy males aged 21-31 participated in 2-day experiments for each light condition. On the first experimental day (day 1), subjects were exposed to dim light (<30 lux) for 3 h in the morning (09:00-12:00). On the same day, saliva samples were taken in dim light (<30 lux) every 30 min from 21:00 to 01:00 to determine the DLMO phase. The subjects were allowed to sleep from 01:00 to 08:00. On the second experimental day (day 2), the subjects were exposed to experimental light conditions for 3 h in the morning. The experimental schedule after light exposure was the same as on day 1. On comparing day 2 with day 1, significant phase advances of DLMO were obtained at 3000 lux, 6000 lux and 12,000 lux. These findings indicate that exposure to a necessary intensity from an ordinary light source, such as a fluorescent lamp, in the morning within one day affects melatonin secretion.
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Circadian regulation of intracellular G-protein signalling mediates intercellular synchrony and rhythmicity in the suprachiasmatic nucleus. Nat Commun 2011; 2:327. [PMID: 21610730 PMCID: PMC3112533 DOI: 10.1038/ncomms1316] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 04/18/2011] [Indexed: 12/14/2022] Open
Abstract
Synchronous oscillations of thousands of cellular clocks in the suprachiasmatic nucleus (SCN), the circadian centre, are coordinated by precisely timed cell–cell communication, the principle of which is largely unknown. Here we show that the amount of RGS16 (regulator of G protein signalling 16), a protein known to inactivate Gαi, increases at a selective circadian time to allow time-dependent activation of intracellular cyclic AMP signalling in the SCN. Gene ablation of Rgs16 leads to the loss of circadian production of cAMP and as a result lengthens circadian period of behavioural rhythm. The temporally precise regulation of the cAMP signal by clock-controlled RGS16 is needed for the dorsomedial SCN to maintain a normal phase-relationship to the ventrolateral SCN. Thus, RGS16-dependent temporal regulation of intracellular G protein signalling coordinates the intercellular synchrony of SCN pacemaker neurons and thereby defines the 24 h rhythm in behaviour. Circadian rhythm is controlled by the suprachiasmatic nucleus and the mechanisms that control the rhythm are largely undiscovered. In this study, a G protein regulator, RGS16, is shown to be involved in the production of cyclic AMP that is required for the suprachiasmatic nucleus to maintain rhythm
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Krug S, McKinley Brewer J, Bois AS, Bittman EL. Effects of the duper mutation on circadian responses to light. J Biol Rhythms 2011; 26:293-304. [PMID: 21775288 DOI: 10.1177/0748730411411570] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
The circadian mutation duper in Syrian hamsters shortens the free-running circadian period (τ(DD)) by 2 hours when expressed on a tau mutant (τ(ss)) background and by 1 hour on a wild-type background. We have examined the effects of this mutation on phase response curves and entrainment. In contrast to wild types, duper hamsters entrained to 14L:10D with a positive phase angle. Super duper hamsters (expressing duper on a τ(ss) background) showed weak entrainment, while τ(ss) animals either completely failed to entrain or showed sporadic entrainment with episodes of relative coordination. As previously reported, wild-type and τ(ss) hamsters show low amplitude resetting in response to 15-minute light pulses after short-term (10 days) exposure to DD. In contrast, super duper hamsters show high amplitude resetting. This effect is attributable to the duper allele, as hamsters carrying duper on a wild-type background also show large phase shifts. Duper mutants that were born and raised in DD also showed high amplitude resetting in response to 15-minute light pulses, indicating that the effect of the mutation on PRC amplitude is not an aftereffect of entrainment to 14L:10D. Hamsters that are heterozygous for duper do not show amplified resetting curves, indicating that for this property, as for determination of free-running period, the mutant allele is recessive. In a modified Aschoff type II protocol, super duper and duper hamsters show large phase shifts as soon as the second day of DD. Despite the amplification of the PRC in super duper hamsters, the induction of Period1 gene expression in the SCN by light is no greater in these mutants than in wild-type animals. Period2 expression in the SCN did not differ between super duper and wild-type hamsters exposed to light at CT15, but albumin site D-binding protein (Dbp) mRNA showed higher basal levels and greater light induction in the SCN of super duper compared to wild-type animals. These results indicate that the duper mutation alters the amplitude of the circadian oscillator and further distinguish it from the tau mutation.
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Affiliation(s)
- Stefanie Krug
- Department of Biology and Program in Neuroscience and Behavior, University of Massachusetts, Amherst, MA 01003, USA
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Ohdo S, Koyanagi S, Matsunaga N, Hamdan A. Molecular basis of chronopharmaceutics. J Pharm Sci 2011; 100:3560-76. [PMID: 21656520 DOI: 10.1002/jps.22656] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2011] [Revised: 04/23/2011] [Accepted: 05/17/2011] [Indexed: 01/28/2023]
Abstract
Many pathophysiological circumstances vary during 24 h periods. Many physiologic processes undergo biological rhythms, including the sleep-wake rhythm and metabolism. Disruptive effect in the 24 h variations can manifest as the emergence or exacerbation of pathological conditions. So, chronotherapeutics is gaining increasing interest in experimental biology, medicine, pharmacy, and drug delivery. This science and the plethora of information should be used intelligently for optimizing the effectiveness and safety of the drug, relying on the timing of drug intake. These chronopharmacological findings are affected by not only the pharmacodynamics but also pharmacokinetics of drugs. The mammalian circadian pacemaker is located in the suprachiasmatic nucleus. The molecular mechanisms are associated with Clock genes that control the circadian rhythms in physiology, pathology, and behavior. Clock controls several diseases such as metabolic syndrome, cancer, and so on. CLOCK mutation influences the expression of both rhythmic and nonrhythmic genes in wild-type tissues. These genotypic changes lead to phenotypic changes, affecting the drug pharmacokinetic and pharmacodynamic parameters. This review is intended to elaborate system regulating biological rhythms and the applicability in pharmaceutics from viewpoints of the intraindividual and interindividual variabilities of Clock genes.
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Affiliation(s)
- Shigehiro Ohdo
- Department of Pharmaceutics, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
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LeSauter J, Silver R, Cloues R, Witkovsky P. Light exposure induces short- and long-term changes in the excitability of retinorecipient neurons in suprachiasmatic nucleus. J Neurophysiol 2011; 106:576-88. [PMID: 21593396 DOI: 10.1152/jn.00060.2011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The suprachiasmatic nucleus (SCN) is the locus of a hypothalamic circadian clock that synchronizes physiological and behavioral responses to the daily light-dark cycle. The nucleus is composed of functionally and peptidergically diverse populations of cells for which distinct electrochemical properties are largely unstudied. SCN neurons containing gastrin-releasing peptide (GRP) receive direct retinal input via the retinohypothalamic tract. We targeted GRP neurons with a green fluorescent protein (GFP) marker for whole cell patch-clamping. In these neurons, we studied short (0.5-1.5 h)- and long-term (2-6 h) effects of a 1-h light pulse (LP) given 2 h after lights off [Zeitgeber time (ZT) 14:00-15:00] on membrane potential and spike firing. In brain slices taken from light-exposed animals, cells were depolarized, and spike firing rate increased between ZT 15:30 and 16:30. During a subsequent 4-h period beginning around ZT 17:00, GRP neurons from light-exposed animals were hyperpolarized by ∼15 mV. None of these effects was observed in GRP neurons from animals not exposed to light or in immediately adjacent non-GRP neurons whether or not exposed to light. Depolarization of GRP neurons was associated with a reduction in GABA(A)-dependent synaptic noise, whereas hyperpolarization was accompanied both by a loss of GABA(A) drive and suppression of a TTX-resistant leakage current carried primarily by Na. This suggests that, in the SCN, exposure to light may induce a short-term increase in GRP neuron excitability mediated by retinal neurotransmitters and neuropeptides, followed by long-term membrane hyperpolarization resulting from suppression of a leakage current, possibly resulting from genomic signals.
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Affiliation(s)
- Joseph LeSauter
- Department of Psychology, Barnard College, New York, NY, USA
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Karatsoreos IN, Butler MP, Lesauter J, Silver R. Androgens modulate structure and function of the suprachiasmatic nucleus brain clock. Endocrinology 2011; 152:1970-8. [PMID: 21363939 PMCID: PMC3075936 DOI: 10.1210/en.2010-1398] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Gonadal hormones can modulate circadian rhythms in rodents and humans, and androgen receptors are highly localized within the core region of the mouse suprachiasmatic nucleus (SCN) brain clock. Although androgens are known to modulate neural plasticity in other CNS compartments, the role of androgens and their receptors on plasticity in the SCN is unexplored. In the present study, we ask whether androgens influence the structure and function of the mouse SCN by examining the effects of gonadectomy (GDX) on the structure of the SCN circuit and its responses to light, including induction of clock genes and behavioral phase shifting. We found that after GDX, glial fibrillary acidic protein increased with concomitant decreases in the expression of the synaptic proteins synaptophysin and postsynaptic density 95. We also found that GDX exerts effects on the molecular and behavioral responses to light that are phase dependent. In late night [circadian time (CT)21], GDX increased light-induced mPer1 but not mPer2 expression compared with intact (INT) controls. In contrast, in early night (CT13.5), GDX decreased light induced mPer2 but had no effect on mPer1. At CT13.5, GDX animals also showed larger phase delays than did INT. Treatment of GDX animals with the nonaromatizable androgen dihydrotestosterone restored glial fibrillary acidic protein, postsynaptic density 95, and synaptophysin in the SCN and reinstated the INT pattern of molecular and behavioral responses to light. Together, the results reveal a role for androgens in regulating circuitry in the mouse SCN, with functional consequences for clock gene expression and behavioral responses to photic phase resetting stimuli.
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Affiliation(s)
- Ilia N Karatsoreos
- Department of Psychology, Columbia University, New York, New York 10027, USA
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