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Morimoto T, Yoshikawa T, Nagano M, Shigeyoshi Y. Regionality of short and long period oscillators in the suprachiasmatic nucleus and their manner of synchronization. PLoS One 2022; 17:e0276372. [PMID: 36256675 PMCID: PMC9578605 DOI: 10.1371/journal.pone.0276372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 10/05/2022] [Indexed: 11/18/2022] Open
Abstract
In mammals, the center of the circadian clock is located in the suprachiasmatic nucleus (SCN) of the hypothalamus. Many studies have suggested that there are multiple regions generating different circadian periods within the SCN, but the exact localization of the regions has not been elucidated. In this study, using a transgenic rat carrying a destabilized luciferase reporter gene driven by a regulatory element of Per2 gene (Per2::dLuc), we investigated the regional variation of period lengths in horizontal slices of the SCN. We revealed a distinct caudal medial region (short period region, SPR) and a rostro-lateral region (long period region, LPR) that generate circadian rhythms with periods shorter than and longer than 24 hours, respectively. We also found that the core region of the SCN marked by dense VIP (vasoactive intestinal peptide) mRNA-expressing neurons covered a part of LPR, and that the shell region of the SCN contains both SPR and the rest of the LPR. Furthermore, we observed how synchronization is achieved between regions generating distinct circadian periods in the SCN. We found that the longer circadian rhythm of the rostral region appears to entrain the circadian rhythm in the caudal region. Our findings clarify the localization of regionality of circadian periods and the mechanism by which the integrated circadian rhythm is formed in the SCN.
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Affiliation(s)
- Tadamitsu Morimoto
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Kindai University, Osaka-Sayama, Osaka, Japan
| | - Tomoko Yoshikawa
- Organization for International Education and Exchange, University of Toyama, Toyama, Japan
| | - Mamoru Nagano
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Kindai University, Osaka-Sayama, Osaka, Japan
| | - Yasufumi Shigeyoshi
- Department of Anatomy and Neurobiology, Graduate School of Medicine, Kindai University, Osaka-Sayama, Osaka, Japan,* E-mail:
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Jeong EM, Song YM, Kim JK. Combined multiple transcriptional repression mechanisms generate ultrasensitivity and oscillations. Interface Focus 2022; 12:20210084. [PMID: 35450279 PMCID: PMC9010851 DOI: 10.1098/rsfs.2021.0084] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 02/24/2022] [Indexed: 12/14/2022] Open
Abstract
Transcriptional repression can occur via various mechanisms, such as blocking, sequestration and displacement. For instance, the repressors can hold the activators to prevent binding with DNA or can bind to the DNA-bound activators to block their transcriptional activity. Although the transcription can be completely suppressed with a single mechanism, multiple repression mechanisms are used together to inhibit transcriptional activators in many systems, such as circadian clocks and NF-κB oscillators. This raises the question of what advantages arise if seemingly redundant repression mechanisms are combined. Here, by deriving equations describing the multiple repression mechanisms, we find that their combination can synergistically generate a sharply ultrasensitive transcription response and thus strong oscillations. This rationalizes why the multiple repression mechanisms are used together in various biological oscillators. The critical role of such combined transcriptional repression for strong oscillations is further supported by our analysis of formerly identified mutations disrupting the transcriptional repression of the mammalian circadian clock. The hitherto unrecognized source of the ultrasensitivity, the combined transcriptional repressions, can lead to robust synthetic oscillators with a previously unachievable simple design.
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Affiliation(s)
- Eui Min Jeong
- Department of Mathematical Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- Biomedical Mathematics Group, Institute for Basic Science, Daejeon 34126, Republic of Korea
| | - Yun Min Song
- Department of Mathematical Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- Biomedical Mathematics Group, Institute for Basic Science, Daejeon 34126, Republic of Korea
| | - Jae Kyoung Kim
- Department of Mathematical Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- Biomedical Mathematics Group, Institute for Basic Science, Daejeon 34126, Republic of Korea
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3
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Rizk AA, Jenkins BW, Al-Sabagh Y, Hamidullah S, Reitz CJ, Rasouli M, Martino TA, Khokhar JY. The Impact of Sex, Circadian Disruption, and the ClockΔ19/Δ19 Genotype on Alcohol Drinking in Mice. Genes (Basel) 2022; 13:genes13040701. [PMID: 35456507 PMCID: PMC9031797 DOI: 10.3390/genes13040701] [Citation(s) in RCA: 2] [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: 01/28/2022] [Revised: 03/25/2022] [Accepted: 04/06/2022] [Indexed: 01/05/2023] Open
Abstract
Shift work is associated with increased alcohol drinking, more so in males than females, and is thought to be a coping mechanism for disrupted sleep cycles. However, little is presently known about the causal influence of circadian rhythm disruptions on sex differences in alcohol consumption. In this study, we disrupted circadian rhythms in female and male mice using both environmental (i.e., shifting diurnal cycles) and genetic (i.e., ClockΔ19/Δ19 mutation) manipulations, and measured changes in alcohol consumption and preference using a two-bottle choice paradigm. Alcohol consumption and preference, as well as food and water consumption, total caloric intake, and weight were assessed in adult female and male ClockΔ19/Δ19 mutant mice or wild-type (WT) litter-mates, housed under a 12-hour:12-hour light:dark (L:D) cycle or a shortened 10-hour:10-hour L:D cycle. Female WT mice (under both light cycles) increased their alcohol consumption and preference over time, a pattern not observed in male WT mice. Compared to WT mice, ClockΔ19/Δ19 mice displayed increased alcohol consumption and preference. Sex differences were not apparent in ClockΔ19/Δ19 mice, with or without shifting diurnal cycles. In conclusion, sex differences in alcohol consumption patterns are evident and increase with prolonged access to alcohol. Disrupting circadian rhythms by mutating the Clock gene greatly increases alcohol consumption and abolishes sex differences present in WT animals.
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Physical Interaction between Cyclin-Dependent Kinase 5 (CDK5) and Clock Factors Affects the Circadian Rhythmicity in Peripheral Oscillators. Clocks Sleep 2022; 4:185-201. [PMID: 35323171 PMCID: PMC8946863 DOI: 10.3390/clockssleep4010017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/22/2022] [Accepted: 03/01/2022] [Indexed: 11/17/2022] Open
Abstract
Circadian rhythms are self-sustained oscillators with a period of 24 h that is based on the output of transcriptional and post-translational feedback loops. Phosphorylation is considered one of the most important post-translational modifications affecting rhythmicity from cyanobacteria to mammals. For example, the lack of cyclin-dependent kinase 5 (CDK5) shortened the period length of the circadian oscillator in the Suprachiasmatic Nuclei (SCN) of mice via the destabilization of the PERIOD 2 (PER2) protein. Here, we show that CDK5 kinase activity and its interaction with clock components, including PER2 and CLOCK, varied over time in mouse embryonic fibroblast cells. Furthermore, the deletion of Cdk5 from cells resulted in a prolonged period and shifted the transcription of clock-controlled genes by about 2 to 4 h with a simple delay of chromatin binding of ARNTL (BMAL1) CLOCK. Taken together, our data indicate that CDK5 is critically involved in regulating the circadian clock in vitro at the molecular level.
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Sujino M, Koinuma S, Minami Y, Shigeyoshi Y. Heavy Water Lengthens the Molecular Circadian Clock Period in the Suprachiasmatic Nucleus of Mice In Vitro. J Biol Rhythms 2021; 36:410-418. [PMID: 33969745 DOI: 10.1177/07487304211012905] [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] [Indexed: 11/17/2022]
Abstract
Heavy water lengthens the periods of circadian rhythms in various plant and animal species. Many studies have reported that drinking heavy water lengthens the periods of circadian activity rhythms of rodents by slowing the clock mechanism in the suprachiasmatic nucleus (SCN), the mammalian circadian center. The SCN clock is stable and robust against disturbance, due to its intercellular network. It is unclear whether this robustness provides resistance to the effects of heavy water. Here, we report that heavy water lengthened the rhythm period of clock gene expression of the SCN and peripheral tissues in vitro using a PERIOD2::LUCIFERASE bioluminescence reporter. Our results show that the period-elongation rate of the SCN is similar to those of other tissues. Therefore, the intercellular network of the SCN is not resistant to the period-elongation effect of heavy water.
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Affiliation(s)
- Mitsugu Sujino
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama, Japan
| | - Satoshi Koinuma
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama, Japan
| | - Yoichi Minami
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama, Japan
| | - Yasufumi Shigeyoshi
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama, Japan
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Ribeiro RFN, Cavadas C, Silva MMC. Small-molecule modulators of the circadian clock: Pharmacological potentials in circadian-related diseases. Drug Discov Today 2021; 26:1620-1641. [PMID: 33781946 DOI: 10.1016/j.drudis.2021.03.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 02/20/2021] [Accepted: 03/16/2021] [Indexed: 12/29/2022]
Abstract
Disruption of circadian oscillations has a wide-ranging impact on health, with the potential to induce the development of clock-related diseases. Small-molecule modulators of the circadian clock (SMMCC) target core or noncore clock proteins, modulating physiological effects as a consequence of agonist, inverse agonist, or antagonist interference. These pharmacological modulators are usually identified using chemical screening of large libraries of active compounds. However, target-based screens, chemical optimization, and circadian crystallography have recently assisted in the identification of these compounds. In this review, we focus on established and novel SMMCCs targeting both core and noncore clock proteins, identifying their circadian targets, detailed circadian effects, and specific physiological effects. In addition, we discuss their therapeutic potential for the treatment of diverse clock-related disorders (such as metabolic-associated disorders, autoimmune diseases, mood disorders, and cancer) and as chronotherapeutics. Future perspectives are also considered, such as clinical trials, and potential safety hazards, including those in the absence of clinical trials.
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Affiliation(s)
- Rodrigo F N Ribeiro
- Centre for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Centre for Innovation in Biomedicine and Biotechnology (CIBB), University of Coimbra, Portugal; Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Cláudia Cavadas
- Centre for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Centre for Innovation in Biomedicine and Biotechnology (CIBB), University of Coimbra, Portugal; Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal.
| | - Maria Manuel C Silva
- Centre for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Centre for Innovation in Biomedicine and Biotechnology (CIBB), University of Coimbra, Portugal; Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal.
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Minami Y, Yoshikawa T, Nagano M, Koinuma S, Morimoto T, Fujioka A, Furukawa K, Ikegami K, Tatemizo A, Egawa K, Tamaru T, Taniguchi T, Shigeyoshi Y. Transgenic rats expressing dominant negative BMAL1 showed circadian clock amplitude reduction and rapid recovery from jet lag. Eur J Neurosci 2020; 53:1783-1793. [PMID: 33351992 DOI: 10.1111/ejn.15085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/19/2020] [Accepted: 12/09/2020] [Indexed: 12/01/2022]
Abstract
The circadian rhythms are endogenous rhythms of about 24 h, and are driven by the circadian clock. The clock centre locates in the suprachiasmatic nucleus. Light signals from the retina shift the circadian rhythm in the suprachiasmatic nucleus, but there is a robust part of the suprachiasmatic nucleus that causes jet lag after an abrupt shift of the environmental lighting condition. To examine the effect of attenuated circadian rhythm on the duration of jet lag, we established a transgenic rat expressing BMAL1 dominant negative form under control by mouse Prnp-based transcriptional regulation cassette [BMAL1 DN (+)]. The transgenic rats became active earlier than controls, just after light offset. Compared to control rats, BMAL1 DN (+) rats showed smaller circadian rhythm amplitudes in both behavioural and Per2 promoter driven luciferase activity rhythms. A light pulse during the night resulted in a larger phase shift of behavioural rhythm. Furthermore, at an abrupt shift of the light-dark cycle, BMAL1 DN (+) rat showed faster entrainment to the new light-dark cycle compared to controls. The circadian rhythm has been regarded as a limit cycle phenomenon, and our results support the hypothesis that modification of the amplitude of the circadian limit cycle leads to alteration in the length of the phase shift.
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Affiliation(s)
- Yoichi Minami
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama, Osaka, Japan
| | - Tomoko Yoshikawa
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama, Osaka, Japan
| | - Mamoru Nagano
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama, Osaka, Japan
| | - Satoshi Koinuma
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama, Osaka, Japan
| | - Tadamitsu Morimoto
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama, Osaka, Japan
| | - Atsuko Fujioka
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama, Osaka, Japan
| | - Keiichi Furukawa
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama, Osaka, Japan
| | - Keisuke Ikegami
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama, Osaka, Japan
| | - Atsuhiro Tatemizo
- Central Research Facilities, Faculty of Medicine Center for Animal Experiment, Kindai University Faculty of Medicine, Kindai University, Osakasayama, Osaka, Japan
| | - Kentaro Egawa
- Central Research Facilities, Faculty of Medicine Center for Animal Experiment, Kindai University Faculty of Medicine, Kindai University, Osakasayama, Osaka, Japan
| | - Teruya Tamaru
- Department of Physiology and Advanced Research Center for Medical Science, Toho University School of Medicine, Ota-ku, Tokyo, Japan
| | - Taizo Taniguchi
- Research Institute for Human Health Science, Konan University, Kobe, Hyogo, Japan
| | - Yasufumi Shigeyoshi
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama, Osaka, Japan
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Chrobok L, Northeast RC, Myung J, Cunningham PS, Petit C, Piggins HD. Timekeeping in the hindbrain: a multi-oscillatory circadian centre in the mouse dorsal vagal complex. Commun Biol 2020; 3:225. [PMID: 32385329 PMCID: PMC7210107 DOI: 10.1038/s42003-020-0960-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 04/21/2020] [Indexed: 02/06/2023] Open
Abstract
Metabolic and cardiovascular processes controlled by the hindbrain exhibit 24 h rhythms, but the extent to which the hindbrain possesses endogenous circadian timekeeping is unresolved. Here we provide compelling evidence that genetic, neuronal, and vascular activities of the brainstem’s dorsal vagal complex are subject to intrinsic circadian control with a crucial role for the connection between its components in regulating their rhythmic properties. Robust 24 h variation in clock gene expression in vivo and neuronal firing ex vivo were observed in the area postrema (AP) and nucleus of the solitary tract (NTS), together with enhanced nocturnal responsiveness to metabolic cues. Unexpectedly, we also find functional and molecular evidence for increased penetration of blood borne molecules into the NTS at night. Our findings reveal that the hindbrain houses a local network complex of neuronal and non-neuronal autonomous circadian oscillators, with clear implications for understanding local temporal control of physiology in the brainstem. Lukasz Chrobok, Rebecca Northeast et al. show circadian variation in clock gene expression and neuronal firing within the area postrema and the nucleus of the solitary tract in mice. These regions also exhibit variation in metabolic processes and blood-brain barrier permeability across the 24 hour cycle suggesting the presence of circadian oscillators within the dorsal vagal complex.
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Affiliation(s)
- Lukasz Chrobok
- Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK.,Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa Street 9, 30-387, Krakow, Poland
| | - Rebecca C Northeast
- Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Jihwan Myung
- Graduate Institute of Mind, Brain, and Consciousness, Taipei Medical University, No.172-1 Sec. 2 Keelung Road, Da'an District, Taipei, 106, Taiwan.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, No. 250, Wu-Hsing Street, Taipei, 110, Taiwan.,Brain and Consciousness Research Centre, Taipei Medical University-Shuang Ho Hospital, Ministry of Health and Welfare, No. 291 Zhongzheng Road, Zhonghe District, New Taipei City, 235, Taiwan
| | - Peter S Cunningham
- Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Cheryl Petit
- Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Hugh D Piggins
- Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK. .,School of Physiology, Pharmacology, and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol, BS8 1TD, UK.
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Ikegami K, Shigeyoshi Y, Masubuchi S. Circadian Regulation of IOP Rhythm by Dual Pathways of Glucocorticoids and the Sympathetic Nervous System. Invest Ophthalmol Vis Sci 2020; 61:26. [PMID: 32182332 PMCID: PMC7401506 DOI: 10.1167/iovs.61.3.26] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 01/09/2020] [Indexed: 01/15/2023] Open
Abstract
Purpose Elevated IOP can cause the development of glaucoma. The circadian rhythm of IOP depends on the dynamics of the aqueous humor and is synchronized with the circadian rhythm pacemaker, that is, the suprachiasmatic nucleus. The suprachiasmatic nucleus resets peripheral clocks via sympathetic nerves or adrenal glucocorticoids. However, the detailed mechanisms underlying IOP rhythmicity remain unclear. The purpose of this study was to verify this regulatory pathway. Methods Adrenalectomy and/or superior cervical ganglionectomy were performed in C57BL/6J mice. Their IOP rhythms were measured under light/dark cycle and constant dark conditions. Ocular administration of corticosterone or norepinephrine was also performed. Localization of adrenergic receptors, glucocorticoid receptors, and clock proteins Bmal1 and Per1 were analyzed using immunohistochemistry. Period2::luciferase rhythms in the cultured iris/ciliary bodies of adrenalectomized and/or superior cervical ganglionectomized mice were monitored to evaluate the effect of the procedures on the local clock. The IOP rhythm of retina and ciliary epithelium-specific Bmal1 knockout mice were measured to determine the significance of the local clock. Results Adrenalectomy and superior cervical ganglionectomy disrupted IOP rhythms and the circadian clock in the iris/ciliary body cultures. Instillation of corticosterone and norepinephrine restored the IOP rhythm. β2-Adrenergic receptors, glucocorticoid receptors, and clock proteins were strongly expressed within the nonpigmented epithelia of the ciliary body. However, tissue-specific Bmal1 knock-out mice maintained their IOP rhythm. Conclusions These findings suggest direct driving of the IOP rhythm by the suprachiasmatic nucleus, via the dual corticosterone and norepinephrine pathway, but not the ciliary clock, which may be useful for chronotherapy of glaucoma.
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Affiliation(s)
- Keisuke Ikegami
- Department of Physiology, School of Medicine, Aichi Medical University, Nagakute, Aichi, Japan
| | - Yasufumi Shigeyoshi
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osaka-Sayama, Osaka,Japan
| | - Satoru Masubuchi
- Department of Physiology, School of Medicine, Aichi Medical University, Nagakute, Aichi, Japan
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Northeast RC, Chrobok L, Hughes ATL, Petit C, Piggins HD. Keeping time in the lamina terminalis: Novel oscillator properties of forebrain sensory circumventricular organs. FASEB J 2019; 34:974-987. [PMID: 31914667 PMCID: PMC6972491 DOI: 10.1096/fj.201901111r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 09/19/2019] [Accepted: 10/15/2019] [Indexed: 12/11/2022]
Abstract
Drinking behavior and osmotic regulatory mechanisms exhibit clear daily variation which is necessary for achieving the homeostatic osmolality. In mammals, the master clock in the brain's suprachiasmatic nuclei has long been held as the main driver of circadian (24 h) rhythms in physiology and behavior. However, rhythmic clock gene expression in other brain sites raises the possibility of local circadian control of neural activity and function. The subfornical organ (SFO) and the organum vasculosum laminae terminalis (OVLT) are two sensory circumventricular organs (sCVOs) that play key roles in the central control of thirst and water homeostasis, but the extent to which they are subject to intrinsic circadian control remains undefined. Using a combination of ex vivo bioluminescence and in vivo gene expression, we report for the first time that the SFO contains an unexpectedly robust autonomous clock with unusual spatiotemporal characteristics in core and noncore clock gene expression. Furthermore, putative single-cell oscillators in the SFO and OVLT are strongly rhythmic and require action potential-dependent communication to maintain synchrony. Our results reveal that these thirst-controlling sCVOs possess intrinsic circadian timekeeping properties and raise the possibility that these contribute to daily regulation of drinking behavior.
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Affiliation(s)
- Rebecca C Northeast
- Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| | - Lukasz Chrobok
- Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| | - Alun T L Hughes
- Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| | - Cheryl Petit
- Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| | - Hugh D Piggins
- Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
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Abstract
Disruption of circadian clocks is strongly associated with mood disorders. Chronotherapies targeting circadian rhythms have been shown to be very effective treatments of mood disorders, but still are not widely used in clinical practice. The mechanisms by which circadian disruption leads to mood disorders are poorly characterized and, therefore, may not convince clinicians to apply chronotherapies. Hence, in this review, we describe specific potential mechanisms, in order to make this connection more credible to clinicians. We believe that four major features of disrupted clocks may contribute to the development of mood disorders: (1) loss of synchronization to environmental 24-h rhythms, (2) internal desynchronization among body clocks, (3) low rhythm amplitude, and (4) changes in sleep architecture. Discussing these attributes and giving plausible examples, we will discuss prospects for relatively simple chronotherapies addressing these features that are easy to implement in clinical practice. Key messages In this review, we describe specific potential mechanisms by which disrupted clocks may contribute to the development of mood disorders: (1) loss of synchronization to environmental 24-h rhythms, (2) internal desynchronization among body clocks, (3) low rhythm amplitude, and (4) changes in sleep architecture. We provide prospects for relatively simple chronotherapies addressing these features that are easy to implement in clinical practice.
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Affiliation(s)
- Anisja Hühne
- a Circadian Biology Group, Department of Psychiatry , Ludwig Maximilian University , Munich , Germany
| | - David K Welsh
- b Veterans Affairs San Diego Healthcare System , San Diego , CA , USA.,c Department of Psychiatry & Center for Circadian Biology , University of California San Diego , La Jolla , CA , USA
| | - Dominic Landgraf
- a Circadian Biology Group, Department of Psychiatry , Ludwig Maximilian University , Munich , Germany
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