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Li T, Jiang YT, Qi XZ, Chen P, Zhang JH, Luo F, Qiao J, Gu J, Du GS, Wang Q. Circadian disturbance induces erectile dysfunction by impairing endothelial function. Asian J Androl 2023; 26:00129336-990000000-00143. [PMID: 38048170 PMCID: PMC10919418 DOI: 10.4103/aja202345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 09/27/2023] [Indexed: 12/06/2023] Open
Abstract
ABSTRACT In order to explore the impact of circadian disturbance on erectile function, we randomly divided 24 adult male rats into groups of control (light on at 8:00 a.m. and off at 8:00 p.m.), dark/dark (DD; constant dark), light/light (LL; constant light), and shift dark/light (DL; light off at 8:00 a.m. and on at 8:00 p.m.). Four weeks later, erectile function was measured and corpora cavernosa were harvested for analysis. The maximum intracavernous pressure (mICP) and mICP/mean arterial pressure (MAP) ratio in the DD, LL, and DL groups were significantly lower than that in the control group. The LL and DL groups showed significantly attenuated endothelial nitric oxide synthase (eNOS), while DD, LL, and DL showed reduced neuronal nitric oxide synthase (nNOS) at both mRNA and protein levels. The production of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) was inhibited by altered light/dark cycles to varying degrees. Circadian disturbance impaired endothelial function and contributed to erectile dysfunction. For the core circadian elements, mRNA expression of circadian locomotor output cycles kaput (Clock) and brain/muscle aryl-hydrocarbon receptor nuclear translocator-like protein 1 (Bmal1) was elevated in the DL group, but their protein expression was not significantly changed. DD, LL, and DL increased period 1 (Per1) and Per3 levels, while LL and DL increased PER1 levels. No significant difference was found for Per2 levels, and PER2 and PER3 concentrations were not significantly changed. Moreover, LL and DL significantly increased cryptochrome-1 (CRY1) and CRY2 at both mRNA and protein levels. The altered light/dark rat model showed that circadian disturbance contributed to erectile dysfunction probably by impairing endothelial function. Meanwhile, the core circadian elements were detected in the corpora cavernosa, but these were disrupted. However, which circadian element regulates erectile function and how it works need further analysis.
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Affiliation(s)
- Tao Li
- Department of Urology, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China
- Department of Urology, Guizhou Provincial People’s Hospital, Guiyang 550002, China
| | - Yi-Ting Jiang
- Department of Otorhinolaryngology, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China
| | - Xin-Zhu Qi
- Guizhou Institute for Food and Drug Control, Guiyang 550004, China
| | - Peng Chen
- Department of Urology, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China
| | - Jun-Hao Zhang
- Department of Urology, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China
| | - Fu Luo
- Department of Reproductive Center, Guizhou Provincial People’s Hospital, Guiyang 550002, China
| | - Jun Qiao
- Department of Urology, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China
| | - Jiang Gu
- Department of Urology, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China
| | - Guang-Shi Du
- Translational Medicine Research Center of Guizhou Medical University, Guiyang 550025, China
| | - Qiang Wang
- Department of Urology, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China
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Lin YP, Shen YY, Shiu YB, Charng YY, Grimm B. Chlorophyll dephytylase 1 and chlorophyll synthase: a chlorophyll salvage pathway for the turnover of photosystems I and II. Plant J 2022; 111:979-994. [PMID: 35694901 DOI: 10.1111/tpj.15865] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/02/2022] [Indexed: 06/15/2023]
Abstract
Chlorophyll (Chl) is made up of the tetrapyrrole chlorophyllide and phytol, a diterpenoid alcohol. The photosynthetic protein complexes utilize Chl for light harvesting to produce biochemical energy for plant development. However, excess light and adverse environmental conditions facilitate generation of reactive oxygen species, which damage photosystems I and II (PSI and PSII) and induce their turnover. During this process, Chl is released, and is thought to be recycled via dephytylation and rephytylation. We previously demonstrated that Chl recycling in Arabidopsis under heat stress is mediated by the enzymes chlorophyll dephytylase 1 (CLD1) and chlorophyll synthase (CHLG) using chlg and cld1 mutants. Here, we show that the mutants with high CLD1/CHLG ratio, by different combinations of chlg-1 (a knock-down mutant) and the hyperactive cld1-1 alleles, develop necrotic leaves when grown under long- and short-day, but not continuous light conditions, owing to the accumulation of chlorophyllide in the dark. Combination of chlg-1 with cld1-4 (a knock-out mutant) leads to reduced chlorophyllide accumulation and necrosis. The operation of CLD1 and CHLG as a Chl salvage pathway was also explored in the context of Chl recycling during the turnover of Chl-binding proteins of the two photosystems. CLD1 was found to interact with CHLG and the light-harvesting complex-like proteins OHP1 and LIL3, implying that auxiliary factors are required for this process.
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Affiliation(s)
- Yao-Pin Lin
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, Philippstraße 13 Building 12, 10115, Berlin, Germany
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 11529, Taiwan, ROC
| | - Yu-Yen Shen
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 11529, Taiwan, ROC
| | - Yen-Bin Shiu
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 11529, Taiwan, ROC
| | - Yee-Yung Charng
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 11529, Taiwan, ROC
| | - Bernhard Grimm
- Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, Philippstraße 13 Building 12, 10115, Berlin, Germany
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Ma H, Li L, Yan J, Zhang Y, Ma X, Li Y, Yuan Y, Yang X, Yang L, Guo J. The Resonance and Adaptation of Neurospora crassa Circadian and Conidiation Rhyth ms to Short Light-Dark Cycles. J Fungi (Basel) 2021; 8:27. [PMID: 35049967 DOI: 10.3390/jof8010027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 12/21/2021] [Accepted: 12/25/2021] [Indexed: 11/17/2022] Open
Abstract
Circadian clocks control the physiological and behavioral rhythms to adapt to the environment with a period of ~24 h. However, the influences and mechanisms of the extreme light/dark cycles on the circadian clock remain unclear. We showed that, in Neurospora crassa, both the growth and the microconidia production contribute to adaptation in LD12:12 (12 h light/12 h dark, periodically). Mathematical modeling and experiments demonstrate that in short LD cycles, the expression of the core clock protein FREQUENCY was entrained to the LD cycles when LD > 3:3 while it free ran when T ≤ LD3:3. The conidial rhythmicity can resonate with a series of different LD conditions. Moreover, we demonstrate that the existence of unknown blue light photoreceptor(s) and the circadian clock might promote the conidiation rhythms that resonate with the environment. The ubiquitin E3 ligase FWD-1 and the previously described CRY-dependent oscillator system were implicated in regulating conidiation under short LD conditions. These findings shed new light on the resonance of Neurospora circadian clock and conidiation rhythms to short LD cycles, which may benefit the understandings of both the basic regulatory aspects of circadian clock and the adaptation of physiological rhythms to the extreme conditions.
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Awan UA, Meng L, Xia S, Raza MF, Zhang Z, Zhang H. Isolation, fermentation, and formulation of entomopathogenic fungi virulent against adults of Diaphorina citri. Pest Manag Sci 2021; 77:4040-4053. [PMID: 33896118 DOI: 10.1002/ps.6429] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 04/13/2021] [Accepted: 04/25/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Mycopesticides are important for integrated management of the Asian citrus psyllid, Diaphorina citri. However, there are few reports on the fermentation and formulation for mycopesticides with high virulence against D. citri. RESULTS From four different locations in South China, 12 fungal strains were isolated and classified into Beauveria bassiana (two isolates), Fusarium fujikuroi (five isolates), and Cordyceps javanica (five isolates) based on the phylogenetic analysis of ITS1-5.8S rDNA-ITS4 and morphology of colonies and conidia. Based on the highest initial virulence (86.52 ± 2.35%) and best growth characteristics, F-HY002-ACPHali was further optimized for biphasic fermentation (7.85 ± 2.62 × 109 g-1 dry substrate) with soybean meal + cottonseed flour (1:1) as the solid substrate and full light as the light/dark cycle. Furthermore, the oil-based conidial formulation was optimized with sesame oil as an effective carrier, which significantly enhanced conidial shelf life up to 16 weeks at 26 °C and 4 °C, thermo-stress (50 °C) and UV-B stress resistance, and virulence against adults of D. citri with increased mortalities and decreased LT50 in comparison to that of unformulated conidia. CONCLUSION Our results not only provide a valuable native strain with high virulence against adults of D. citri, but also imply the soybean meal + cottonseed flour as valuable solid substrate, full-light exposure as environmental stimuli for solid-state fermentation, and the sesame oil as an effective carrier for the formulation of the C. javanica. These findings will facilitate the development of a potential mycopesticide for the biological control of Asian citrus psyllid.
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Affiliation(s)
- Umar Anwar Awan
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Horticultural Plant Biology (MOE), College of Plant Science and Technology, Institute of Urban and Horticultural Entomology, Huazhong Agricultural University, Wuhan, China
| | - Lixue Meng
- School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, China
| | - Shuang Xia
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Horticultural Plant Biology (MOE), College of Plant Science and Technology, Institute of Urban and Horticultural Entomology, Huazhong Agricultural University, Wuhan, China
| | - Muhammad Fahim Raza
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Horticultural Plant Biology (MOE), College of Plant Science and Technology, Institute of Urban and Horticultural Entomology, Huazhong Agricultural University, Wuhan, China
| | - Zhenyu Zhang
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Horticultural Plant Biology (MOE), College of Plant Science and Technology, Institute of Urban and Horticultural Entomology, Huazhong Agricultural University, Wuhan, China
| | - Hongyu Zhang
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Horticultural Plant Biology (MOE), College of Plant Science and Technology, Institute of Urban and Horticultural Entomology, Huazhong Agricultural University, Wuhan, China
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Deurveilher S, Ko KR, Saumure BSC, Robertson GS, Rusak B, Semba K. Altered circadian activity and sleep/wake rhythms in the stable tubule only polypeptide (STOP) null mouse model of schizophrenia. Sleep 2021; 44:5981350. [PMID: 33186470 DOI: 10.1093/sleep/zsaa237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 10/14/2020] [Indexed: 12/27/2022] Open
Abstract
Sleep and circadian rhythm disruptions commonly occur in individuals with schizophrenia. Stable tubule only polypeptide (STOP) knockout (KO) mice show behavioral impairments resembling symptoms of schizophrenia. We previously reported that STOP KO mice slept less and had more fragmented sleep and waking than wild-type littermates under a light/dark (LD) cycle. Here, we assessed the circadian phenotype of male STOP KO mice by examining wheel-running activity rhythms and EEG/EMG-defined sleep/wake states under both LD and constant darkness (DD) conditions. Wheel-running activity rhythms in KO and wild-type mice were similarly entrained in LD, and had similar free-running periods in DD. The phase delay shift in response to a light pulse given early in the active phase under DD was preserved in KO mice. KO mice had markedly lower activity levels, lower amplitude activity rhythms, less stable activity onsets, and more fragmented activity than wild-type mice in both lighting conditions. KO mice also spent more time awake and less time in rapid eye movement sleep (REMS) and non-REMS (NREMS) in both LD and DD conditions, with the decrease in NREMS concentrated in the active phase. KO mice also showed altered EEG features and higher amplitude rhythms in wake and NREMS (but not REMS) amounts in both lighting conditions, with a longer free-running period in DD, compared to wild-type mice. These results indicate that the STOP null mutation in mice altered the regulation of sleep/wake physiology and activity rhythm expression, but did not grossly disrupt circadian mechanisms.
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Affiliation(s)
- Samuel Deurveilher
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - Kristin Robin Ko
- School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada
| | - Brock St C Saumure
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - George S Robertson
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada.,Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | - Benjamin Rusak
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada.,Department of Psychology & Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - Kazue Semba
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada.,Department of Psychiatry, Dalhousie University, Halifax, NS, Canada.,Department of Psychology & Neuroscience, Dalhousie University, Halifax, NS, Canada
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Anye Cho B, de Carvalho Servia MÁ, Del Río Chanona EA, Smith R, Zhang D. Synergising biomass growth kinetics and transport mechanisms to simulate light/dark cycle effects on photo-production systems. Biotechnol Bioeng 2021; 118:1932-1942. [PMID: 33547805 DOI: 10.1002/bit.27707] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 01/25/2021] [Accepted: 02/03/2021] [Indexed: 11/05/2022]
Abstract
Light attenuation is a primary challenge limiting the upscaling of photobioreactors for sustainable bio-production. One key to this challenge, is to model and optimise the light/dark cycles so that cells within the dark region can be frequently transferred to the light region for photosynthesis. Therefore, this study proposes the first mechanistic model to integrate the light/dark cycle effects into biomass growth kinetics. This model was initially constructed through theoretical derivation based on the intracellular reaction kinetics, and was subsequently modified by embedding a new parameter, effective light coefficient, to account for the effects of culture mixing. To generate in silico process data, a new multiscale reactive transport modelling strategy was developed to couple fluid dynamics with biomass growth kinetics and light transmission. By comparing against previous experimental and computational studies, the multiscale model shows to be of high accuracy. Based on its simulation result, an original correlation was proposed to link effective light coefficient with photobioreactor gas inflow rate; this has not been done before. The impact of this study is that by using the proposed mechanistic model and correlation, we can easily control and optimise photobioreactor gas inflow rates to alleviate light attenuation and maintain a high biomass growth rate.
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Affiliation(s)
- Bovinille Anye Cho
- Department of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
| | | | | | - Robin Smith
- Department of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
| | - Dongda Zhang
- Department of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
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Comai S, De Gregorio D, Posa L, Ochoa-Sanchez R, Bedini A, Gobbi G. Dysfunction of serotonergic activity and emotional responses across the light-dark cycle in mice lacking melatonin MT 2 receptors. J Pineal Res 2020; 69:e12653. [PMID: 32239546 DOI: 10.1111/jpi.12653] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 03/23/2020] [Accepted: 03/24/2020] [Indexed: 12/21/2022]
Abstract
Melatonin (MLT) levels fluctuate according to the external light/dark cycle in both diurnal and nocturnal mammals. We previously demonstrated that melatonin MT2 receptor knockout (MT2 -/- ) mice show a decreased nonrapid eye movement sleep over 24 hours and increased wakefulness during the inactive (light) phase. Here, we investigated the role of MT2 receptors in physiological light/dark cycle fluctuations in the activity of dorsal raphe nucleus (DRN) serotonin (5-HT) neurons and anxiety- and depression-like behavior. We found that the 5-HT burst-firing activity was tonically reduced across the whole 24 hours in MT2 -/- mice compared with MT2 +/+ mice. Importantly, the physiological changes in the spontaneous firing activity of DRN 5-HT neurons during the light/dark cycle were nullified in MT2 -/- mice, with a higher DRN 5-HT neural firing activity during the light phase in MT2 -/- than in MT2 +/+ mice. The role of MT2 receptors over DRN 5-HT neurons was confirmed by acute pharmacological studies in which the selective MT2 receptors agonist UCM1014 dose dependently inhibited DRN 5-HT activity, mostly during the dark phase. Compared with MT2 +/+ , MT2 -/- mice displayed an anxiety-like phenotype in the novelty-suppressed feeding and in the light/dark box tests; while anxiety levels in the light/dark box test were lower during the dark than during the light phase in MT2 +/+ mice, the opposite was seen in MT2 -/- mice. No differences between MT2 +/+ and MT2 -/- mice were observed for depression-like behavior in the forced swim and in the sucrose preference tests. These results suggest that MT2 receptor genetic inactivation impacts 5-HT neurotransmission and interferes with anxiety levels by perturbing the physiologic light/dark pattern.
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Affiliation(s)
- Stefano Comai
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University and McGill University Health Center, Montreal, QC, Canada
- Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy
| | - Danilo De Gregorio
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University and McGill University Health Center, Montreal, QC, Canada
| | - Luca Posa
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University and McGill University Health Center, Montreal, QC, Canada
| | - Rafael Ochoa-Sanchez
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University and McGill University Health Center, Montreal, QC, Canada
| | - Annalida Bedini
- Department of Biomolecular Sciences, University Carlo Bo, Urbino, Italy
| | - Gabriella Gobbi
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University and McGill University Health Center, Montreal, QC, Canada
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McDevitt DS, Graziane NM. Timing of Morphine Administration Differentially Alters Paraventricular Thalamic Neuron Activity. eNeuro 2019; 6:ENEURO. [PMID: 31801741 DOI: 10.1523/ENEURO.0377-19.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/21/2019] [Accepted: 11/26/2019] [Indexed: 12/29/2022] Open
Abstract
The paraventricular thalamic nucleus (PVT) is a brain region involved in regulating arousal, goal-oriented behaviors, and drug seeking, all key factors playing a role in substance use disorder. Given this, we investigated the temporal effects of administering morphine, an opioid with strongly addictive properties, on PVT neuronal function in mice using acute brain slices. Here, we show that morphine administration and electrophysiological recordings that occur during periods of animal inactivity (light cycle) elicit increases in PVT neuronal function during a 24-h abstinence time point. Furthermore, we show that morphine-induced increases in PVT neuronal activity at 24-h abstinence are occluded when morphine administration and recordings are performed during an animals' active state (dark cycle). Based on our electrophysiological results combined with previous findings demonstrating that PVT neuronal activity regulates drug-seeking behaviors, we investigated whether timing morphine administration with periods of vigilance (dark cycle) would decrease drug-seeking behaviors in an animal model of substance use disorder. We found that context-induced morphine-seeking behaviors were intact regardless of the time morphine was administered (e.g., light cycle or dark cycle). Our electrophysiological results suggest that timing morphine with various states of arousal may impact the firing of PVT neurons during abstinence. Although, this may not impact context-induced drug-seeking behaviors.
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López-Canul M, Min SH, Posa L, De Gregorio D, Bedini A, Spadoni G, Gobbi G, Comai S. Melatonin MT 1 and MT 2 Receptors Exhibit Distinct Effects in the Modulation of Body Temperature across the Light/Dark Cycle. Int J Mol Sci 2019; 20:E2452. [PMID: 31108968 DOI: 10.3390/ijms20102452] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/06/2019] [Accepted: 05/10/2019] [Indexed: 12/14/2022] Open
Abstract
Melatonin (MLT) is a neurohormone that regulates many physiological functions including sleep, pain, thermoregulation, and circadian rhythms. MLT acts mainly through two G-protein-coupled receptors named MT1 and MT2, but also through an MLT type-3 receptor (MT3). However, the role of MLT receptor subtypes in thermoregulation is still unknown. We have thus investigated the effects of selective and non-selective MLT receptor agonists/antagonists on body temperature (Tb) in rats across the 12/12-h light-dark cycle. Rectal temperature was measured every 15 min from 4:00 a.m. to 9:30 a.m. and from 4:00 p.m. to 9:30 p.m., following subcutaneous injection of each compound at either 5:00 a.m. or 5:00 p.m. MLT (40 mg/kg) had no effect when injected at 5 a.m., whereas it decreased Tb during the light phase only when injected at 5:00 p.m. This effect was blocked by the selective MT2 receptor antagonist 4P-PDOT and the non-selective MT1/MT2 receptor antagonist, luzindole, but not by the α1/MT3 receptors antagonist prazosin. However, unlike MLT, neither the selective MT1 receptor partial agonist UCM871 (14 mg/kg) nor the selective MT2 partial agonist UCM924 (40 mg/kg) altered Tb during the light phase. In contrast, UCM871 injected at 5:00 p.m. increased Tb at the beginning of the dark phase, whereas UCM924 injected at 5:00 a.m. decreased Tb at the end of the dark phase. These effects were blocked by luzindole and 4P-PDOT, respectively. The MT3 receptor agonist GR135531 (10 mg/kg) did not affect Tb. These data suggest that the simultaneous activation of both MT1 and MT2 receptors is necessary to regulate Tb during the light phase, whereas in a complex but yet unknown manner, they regulate Tb differently during the dark phase. Overall, MT1 and MT2 receptors display complementary but also distinct roles in modulating circadian fluctuations of Tb.
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Puszynska AM, O'Shea EK. ppGpp Controls Global Gene Expression in Light and in Darkness in S. elongatus. Cell Rep 2017; 21:3155-65. [PMID: 29241543 DOI: 10.1016/j.celrep.2017.11.067] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 11/10/2017] [Accepted: 11/17/2017] [Indexed: 01/06/2023] Open
Abstract
The bacterial and plant stringent response involves production of the signaling molecules guanosine tetraphosphate and guanosine pentaphosphate ((p)ppGpp), leading to global reorganization of gene expression. The function of the stringent response has been well characterized in stress conditions, but its regulatory role during unstressed growth is less studied. Here, we demonstrate that (p)ppGpp-deficient strains of S. elongatus have globally deregulated biosynthetic capacity, with increased transcription rate, translation rate, and cell size in unstressed conditions in light and impaired viability in darkness. Synthetic restoration of basal guanosine tetraphosphate (ppGpp) levels is sufficient to recover transcriptional balance and appropriate cell size in light and to rescue viability in light/dark conditions, but it is insufficient to enable efficient dark-induced transcriptional shutdown. Our work underscores the importance of basal ppGpp signaling for regulation of cyanobacterial physiology in the absence of stress and for viability in energy-limiting conditions, highlighting that basal (p)ppGpp level is essential in cyanobacteria in the environmental light/dark cycle.
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Mei L, Fan Y, Lv X, Welsh DK, Zhan C, Zhang EE. Long-term in vivo recording of circadian rhythms in brains of freely moving mice. Proc Natl Acad Sci U S A 2018; 115:4276-81. [PMID: 29610316 DOI: 10.1073/pnas.1717735115] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Endogenous circadian clocks control 24-h physiological and behavioral rhythms in mammals. Here, we report a real-time in vivo fluorescence recording system that enables long-term monitoring of circadian rhythms in the brains of freely moving mice. With a designed reporter of circadian clock gene expression, we tracked robust Cry1 transcription reporter rhythms in the suprachiasmatic nucleus (SCN) of WT, Cry1-/- , and Cry2-/- mice in LD (12 h light, 12 h dark) and DD (constant darkness) conditions and verified that signals remained stable for over 6 mo. Further, we recorded Cry1 transcriptional rhythms in the subparaventricular zone (SPZ) and hippocampal CA1/2 regions of WT mice housed under LD and DD conditions. By using a Cre-loxP system, we recorded Per2 and Cry1 transcription rhythms specifically in vasoactive intestinal peptide (VIP) neurons of the SCN. Finally, we demonstrated the dynamics of Per2 and Cry1 transcriptional rhythms in SCN VIP neurons following an 8-h phase advance in the light/dark cycle.
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Abstract
While animal housing conditions are highly controlled and standardized between different laboratories, there are still many subtle differences that unavoidably influence the host organisms and, consequently, interlaboratory reproducibility. Here, we investigated the physiological and immunological consequences between two light/dark cycle (LDC) lengths (14-h/10-h vs. 12-h/12-h LDC) and two commonly used forms of drinking water (acidified drinking water (AW) versus normal tap water (NW)) in single-housed (SH) mice. Our results indicate that SH mice bred under a 12-h/12-h LDC and NW at the supplier's facility showed increased basal morning plasma corticosterone (CORT) levels even 4 weeks after arrival at our animal facility employing a 14-h/10-h LDC and AW. This effect was even more pronounced two weeks after arrival and had abated after 8 weeks. In agreement, increased plasma adrenocorticotropic hormone (ACTH), adrenal in vitro ACTH sensitivity, as well as relative and absolute adrenal weight normalized during this 8-week exposure to the novel and unfamiliar 14-h/10-h LDC and AW. Employment of a 12-h/12-h LDC in our facility completely abrogated the CORT-elevating effects of the 14-h/10-h LDC, despite these animals drinking AW. When both the water and light conditions were matched to those at the supplier's facility, we observed a further reduction in adrenal weight, increased thymus weight, and decreased pro-inflammatory cytokine secretion of isolated and anti-CD3/28-stimulated mesenteric lymph node cells. In summary, our results indicate that prolonged alteration of both the light phase and drinking water represent severe and long-lasting stressors for laboratory rodents. These findings are of general interest for all scientists obtaining their experimental animals from conventional suppliers.
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Affiliation(s)
- Dominik Langgartner
- a Laboratory for Molecular Psychosomatics, Clinic for Psychosomatic Medicine and Psychotherapy , University Ulm , Ulm , Germany
| | - Sandra Foertsch
- a Laboratory for Molecular Psychosomatics, Clinic for Psychosomatic Medicine and Psychotherapy , University Ulm , Ulm , Germany
| | - Andrea M Füchsl
- a Laboratory for Molecular Psychosomatics, Clinic for Psychosomatic Medicine and Psychotherapy , University Ulm , Ulm , Germany
| | - Stefan O Reber
- a Laboratory for Molecular Psychosomatics, Clinic for Psychosomatic Medicine and Psychotherapy , University Ulm , Ulm , Germany
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Matsumura T, Nakagawa H, Suzuki K, Ninomiya C, Ishiwata T. Influence of circadian disruption on neurotransmitter levels, physiological indexes, and behaviour in rats. Chronobiol Int 2015; 32:1449-57. [PMID: 26595278 DOI: 10.3109/07420528.2015.1105250] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Brain monoamines - such as noradrenaline (NA), dopamine (DA) and serotonin (5-HT) - regulate several important physiological functions, including the circadian rhythm. The purpose of this study was to examine changes in NA, DA and 5-HT levels in various brain regions and their effect on core body temperature (Tc), heart rate (HR) and locomotor activity (Act) in rats following exposure to an artificial light/dark (LD) cycle. For this, male Wistar rats were housed at an ambient temperature (Ta) of 23 °C and 50% relative humidity with free access to food and water. Rats were exposed to either natural (12 h:12 h) or artificial (6 h:6 h) LD cycles for 1 month, after which each brain region was immediately extracted and homogenized to quantify the amounts of NA, DA and 5-HT by high-performance liquid chromatography. Behavioural changes were also monitored by the ambulatory activity test (AAT). Notably, we found that artificial LD cycles disrupted the physiological circadian rhythms of Tc, HR and Act. Although the 5-HT levels of rats with a disrupted circadian rhythm decreased in cell bodies (dorsal and median raphe nuclei) and projection areas (frontal cortex, caudate putamen, preoptic area and suprachiasmatic nucleus) relative to the control group, NA levels increased both in the cell body (locus coeruleus) and projection area (paraventricular hypothalamus). No significant changes were found with respect to DA. Moreover, circadian rhythm-disrupted rats also showed anxious behaviours in AAT. Collectively, the results of this study suggest that the serotonergic and noradrenergic systems, but not the dopaminergic system, are affected by artificial LD cycles in brain regions that control several neural and physiological functions, including the regulation of physiological circadian rhythms, stress responses and behaviour.
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Affiliation(s)
- Takeru Matsumura
- a Graduate School of Community & Human Services , Rikkyo University , Saitama , Japan
| | - Hikaru Nakagawa
- a Graduate School of Community & Human Services , Rikkyo University , Saitama , Japan
| | - Kota Suzuki
- a Graduate School of Community & Human Services , Rikkyo University , Saitama , Japan
| | - Chisa Ninomiya
- a Graduate School of Community & Human Services , Rikkyo University , Saitama , Japan
| | - Takayuki Ishiwata
- a Graduate School of Community & Human Services , Rikkyo University , Saitama , Japan
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Rabouille S, Van de Waal DB, Matthijs HCP, Huisman J. Nitrogen fixation and respiratory electron transport in the cyanobacterium Cyanothece under different light/dark cycles. FEMS Microbiol Ecol 2013; 87:630-8. [PMID: 24236731 DOI: 10.1111/1574-6941.12251] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 10/24/2013] [Accepted: 11/11/2013] [Indexed: 11/30/2022] Open
Abstract
Incompatibility of nitrogen fixation and oxygen production compels unicellular diazotrophic cyanobacteria to perform photosynthesis during daytime and restrict nitrogen fixation to nighttime. The marine diazotroph Cyanothece BG 043511 was grown in continuous culture under three light/dark regimes (16L : 8D, 12L : 12D, and 8L : 16D h); we monitored nitrogen fixation and potential photosynthetic efficiency simultaneously online to reveal how their temporal separation is affected by different LD regimes. An increase in nitrogen fixation rate at night coincided with a rise in pulse-amplitude modulated fluorescence, indicating that the enhanced respiratory electron transport to fuel diazotrophy affects the oxidation state of the plastoquinone pool. This may offer an alternative approach to assess instantaneous nitrogen fixation activity. Regardless of photoperiod, the maximum rate of nitrogen fixation was conserved at about 20 h after the onset of the light. Consequently, nitrogen fixation rates peaked at different moments in the dark: relatively early in the 16L : 8D cycle, at midnight in 12L : 12D, and relatively late in 8L : 16D. Under 16L : 8D, nitrogen fixation extended into the light, demonstrating the functional plasticity of nitrogen fixation in Cyanothece. Highest daily amounts of nitrogen fixed were obtained in 12L : 12D, which is consistent with the natural LD cycle of subtropical latitudes in which Cyanothece thrives.
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Affiliation(s)
- Sophie Rabouille
- Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands; UPMC Univ Paris 06, UMR 7093, LOV, Observatoire océanologique, Villefranche/mer, France; LOV, Observatoire océanologique, CNRS, UMR 7093, Villefranche/mer, France
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Mella-Flores D, Six C, Ratin M, Partensky F, Boutte C, Le Corguillé G, Marie D, Blot N, Gourvil P, Kolowrat C, Garczarek L. Prochlorococcus and Synechococcus have Evolved Different Adaptive Mechanisms to Cope with Light and UV Stress. Front Microbiol 2012; 3:285. [PMID: 23024637 PMCID: PMC3441193 DOI: 10.3389/fmicb.2012.00285] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 07/19/2012] [Indexed: 11/13/2022] Open
Abstract
Prochlorococcus and Synechococcus, which numerically dominate vast oceanic areas, are the two most abundant oxygenic phototrophs on Earth. Although they require solar energy for photosynthesis, excess light and associated high UV radiations can induce high levels of oxidative stress that may have deleterious effects on their growth and productivity. Here, we compared the photophysiologies of the model strains Prochlorococcus marinus PCC 9511 and Synechococcus sp. WH7803 grown under a bell-shaped light/dark cycle of high visible light supplemented or not with UV. Prochlorococcus exhibited a higher sensitivity to photoinactivation than Synechococcus under both conditions, as shown by a larger drop of photosystem II (PSII) quantum yield at noon and different diel patterns of the D1 protein pool. In the presence of UV, the PSII repair rate was significantly depressed at noon in Prochlorococcus compared to Synechococcus. Additionally, Prochlorococcus was more sensitive than Synechococcus to oxidative stress, as shown by the different degrees of PSII photoinactivation after addition of hydrogen peroxide. A transcriptional analysis also revealed dramatic discrepancies between the two organisms in the diel expression patterns of several genes involved notably in the biosynthesis and/or repair of photosystems, light-harvesting complexes, CO(2) fixation as well as protection mechanisms against light, UV, and oxidative stress, which likely translate profound differences in their light-controlled regulation. Altogether our results suggest that while Synechococcus has developed efficient ways to cope with light and UV stress, Prochlorococcus cells seemingly survive stressful hours of the day by launching a minimal set of protection mechanisms and by temporarily bringing down several key metabolic processes. This study provides unprecedented insights into understanding the distinct depth distributions and dynamics of these two picocyanobacteria in the field.
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Affiliation(s)
- Daniella Mella-Flores
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
- Departamento de Ecología, Facultad de Ciencias Biologicas, Pontificia Universidad Catolica de ChileSantiago, Chile
| | - Christophe Six
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
| | - Morgane Ratin
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
| | - Frédéric Partensky
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
| | - Christophe Boutte
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
| | - Gildas Le Corguillé
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- CNRS, FR 2424, Service Informatique et GénomiqueRoscoff, France
| | - Dominique Marie
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
| | - Nicolas Blot
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
- Laboratoire Microorganismes: Génome et Environnement, Clermont Université, Université Blaise PascalClermont-Ferrand, France
- Laboratoire Microorganismes: Génome et Environnement, CNRS, UMR 6023Aubière, France
| | - Priscillia Gourvil
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
| | - Christian Kolowrat
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
- Center for Doctoral Studies, University of ViennaVienna, Austria
| | - Laurence Garczarek
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
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Lacour T, Sciandra A, Talec A, Mayzaud P, Bernard O. DIEL VARIATIONS OF CARBOHYDRATES AND NEUTRAL LIPIDS IN NITROGEN-SUFFICIENT AND NITROGEN-STARVED CYCLOSTAT CULTURES OF ISOCHRYSIS SP.(1). J Phycol 2012; 48:966-75. [PMID: 27009006 DOI: 10.1111/j.1529-8817.2012.01177.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The goal of this study was to investigate the time response of two major carbon (C) reserves, respectively neutral lipids (NL) and total carbohydrate (TC), in the Haptophyte Isochrysis sp. growing in nitrogen (N)-sufficient or N-starved conditions and under light:dark (L:D) cycles. Experiments were carried out in a cyclostat culture system that allowed the following of the dynamics of the main cell compounds at both hourly and daily time scales. Under N-sufficient conditions, the L:D cycles cause the population to be synchronized, with most of the cells dividing at the beginning of the dark period. The C-specific growth rate was maximal around midday and negative during the dark period due to respiration processes. NL and TC both accumulated during the day and consumed during the night. We showed that NL and TC are highly dynamic compounds, as more than three quarters of NL and TC accumulated during the light period were consumed during the dark period. In contrast to NL, phospholipid and glycolipid to C ratios remained quite stable during the light/dark cycles. The major effect of N starvation on the NL and TC dynamics was to uncouple their diel variations from the L:D cycle, in two different ways depending on their respective role during short-term acclimation. Whereas the TC per cell ratio increased rapidly to reach a stable value in response to N starvation, NL per cell continued to oscillate, but with a pattern out of phase with the L:D cycle.
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Affiliation(s)
- Thomas Lacour
- UPMC, Université Paris 06, UMR 7093, Laboratoire d'Océanographie de Villefranche, Villefranche-sur-Mer, France and Centre National de la Recherche Scientifique, UMR 7093, Laboratoire d'Océanographie de Villefranche, Villefranche-sur-Mer, FranceBiocore, INRIA, BP93, 06 902 Sophia-Antipolis cedex, France
| | - Antoine Sciandra
- UPMC, Université Paris 06, UMR 7093, Laboratoire d'Océanographie de Villefranche, Villefranche-sur-Mer, France and Centre National de la Recherche Scientifique, UMR 7093, Laboratoire d'Océanographie de Villefranche, Villefranche-sur-Mer, FranceBiocore, INRIA, BP93, 06 902 Sophia-Antipolis cedex, France
| | - Amélie Talec
- UPMC, Université Paris 06, UMR 7093, Laboratoire d'Océanographie de Villefranche, Villefranche-sur-Mer, France and Centre National de la Recherche Scientifique, UMR 7093, Laboratoire d'Océanographie de Villefranche, Villefranche-sur-Mer, FranceBiocore, INRIA, BP93, 06 902 Sophia-Antipolis cedex, France
| | - Patrick Mayzaud
- UPMC, Université Paris 06, UMR 7093, Laboratoire d'Océanographie de Villefranche, Villefranche-sur-Mer, France and Centre National de la Recherche Scientifique, UMR 7093, Laboratoire d'Océanographie de Villefranche, Villefranche-sur-Mer, FranceBiocore, INRIA, BP93, 06 902 Sophia-Antipolis cedex, France
| | - Olivier Bernard
- UPMC, Université Paris 06, UMR 7093, Laboratoire d'Océanographie de Villefranche, Villefranche-sur-Mer, France and Centre National de la Recherche Scientifique, UMR 7093, Laboratoire d'Océanographie de Villefranche, Villefranche-sur-Mer, FranceBiocore, INRIA, BP93, 06 902 Sophia-Antipolis cedex, France
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