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Diel rhythm of urotensin I mRNA expression and its involvement in the locomotor activity and appetite regulation in olive flounder Paralichthys olivaceus. Comp Biochem Physiol B Biochem Mol Biol 2021; 256:110627. [PMID: 34058375 DOI: 10.1016/j.cbpb.2021.110627] [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: 03/12/2021] [Revised: 05/19/2021] [Accepted: 05/25/2021] [Indexed: 11/21/2022]
Abstract
Urotensin I (UI), a member of the corticotropin-releasing hormone family of peptides, regulates a diverse array of physiological functions, including appetite regulation, defensive behavior and stress response. In this study, firstly, the tissue-specific distribution of UI mRNA in olive flounder (Paralichthys olivaceus) was characterized and we found that UI mRNA was highly expressed in caudal neurosecretory system (CNSS) tissue. Secondly, alignment analysis found that a conserved cAMP response binding (CREB) site and a TATA element were located in the proximal promoter of UI gene. In addition, treatment of forskolin activatated cAMP-CREB pathway and induced the up-regulation of UI mRNA in cultured CNSS, suggesting the role of CREB in regulating the UI mRNA expression. Furthermore, plasma UI concentration and UI mRNA in CNSS showed obvious daily rhythm, with higher values in the daytime while lower values in the nighttime. Thirdly, using bold personality (BP) and shy personality (SP) flounder as an animal model, we found that flounder exhibited significantly higher locomotor activity in the nighttime than in the daytime (P < 0.001), and BP flounder showed significantly higher locomotor activity (P < 0.001) compared with SP flounder both in the daytime and nighttime. Analysis of feeding behavior revealed that BP flounder showed a shorter latency to feed and more attacks to prey. Furthermore, the qPCR and immunohistochemistry results showed that BP flounder expressed significantly lower level of UI mRNA and protein in CNSS tissue. Collectively, our study suggested that the UI plays an important role in locomotor activity and appetite regulation, which provides a basis for understanding the mechanism of defensive behavior and animal personality in flounder.
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Lan Z, Zhang W, Xu J, Lu W. GABA A receptor-mediated inhibition of Dahlgren cells electrical activity in the olive flounder, Paralichthys olivaceus. Gen Comp Endocrinol 2021; 306:113753. [PMID: 33711316 DOI: 10.1016/j.ygcen.2021.113753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 02/10/2021] [Accepted: 02/28/2021] [Indexed: 11/24/2022]
Abstract
γ-Aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the central nervous system. We investigated its potential role as a neurotransmitter in the neuroendocrine Dahlgren cell population of the caudal neurosecretory system (CNSS) of the flounder Paralichthys olivaceus. The application of GABA in vitro resulted in a decrease in electrical activity of Dahlgren cells, followed by an increase of the number of silent cells, together with a decreased firing frequency of all three activity patterns (tonic, phasic, bursting). GABAA receptor agonist etomidate decreased Dahlgren cell firing activity, in a similar way to GABA. The response to GABA was blocked by the GABAA receptor antagonist bicuculline. GABAA receptor gamma2 subunit (Gabrg2) and chloride channel (Clcn2) mRNA expression were significantly upregulated in the CNSS after GABA superfusion. These data suggest that GABA may modulate CNSS activity in vivo mediated by GABAA receptors.
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Affiliation(s)
- Zhaohui Lan
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China
| | - Wei Zhang
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China
| | - Jinling Xu
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China
| | - Weiqun Lu
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China.
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3
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Zou H, Shi M, He F, Guan C, Lu W. Expression of corticotropin releasing hormone in olive flounder (Paralichthys olivaceus) and its transcriptional regulation by c-Fos and the methylation of promoter. Comp Biochem Physiol B Biochem Mol Biol 2021; 251:110523. [DOI: 10.1016/j.cbpb.2020.110523] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/26/2020] [Accepted: 10/09/2020] [Indexed: 12/27/2022]
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Zhang W, Lan Z, Li K, Liu C, Jiang P, Lu W. Inhibitory role of taurine in the caudal neurosecretory Dahlgren cells of the olive flounder, Paralichthys olivaceus. Gen Comp Endocrinol 2020; 299:113613. [PMID: 32950586 DOI: 10.1016/j.ygcen.2020.113613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/05/2020] [Accepted: 09/09/2020] [Indexed: 01/19/2023]
Abstract
Taurine plays role in neural development and physiological functions such as endocrine regulation in the central nervous system (CNS), and it is one of the most abundant free amino acid there. We investigated its potential effect as a neurotransmitter in the group of neuroendocrine Dahlgren cells at flounder Paralichthys olivaceus caudal neurosecretory system (CNSS). The application of taurine in vitro led to a reduction in electrical activity of Dahlgren cells, followed by a rise in the number of silent cells, at the same time the frequency of all three activity patterns (tonic, phasic, bursting) in Dahlgren cells was reduced. Both strychnine (a glycine receptor antagonist) and bicuculline (a GABAA receptor antagonist) can block the response to taurine separately. Transcriptome sequencing analysis showed the existence of glycine receptor (GlyR) and GABAA receptor (GABAAR) in the flounder CNSS, and the GlyR, GABAAR, and Cl- channel mRNA expression were significantly raised after taurine superfusion according to quantitative RT-PCR results. These data indicate that taurine may mediate Dahlgren cell population of CNSS activity in vivo through GlyR and GABAAR, thereby, regulating stress-response.
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Affiliation(s)
- Wei Zhang
- National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China
| | - Zhaohui Lan
- National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China
| | - Kunyu Li
- National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China
| | - Cheng Liu
- National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China
| | - Pengxin Jiang
- National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China
| | - Weiqun Lu
- National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China.
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Lu W, Zhu G, Chen A, Li X, McCrohan CR, Balment R. Gene expression and hormone secretion profile of urotensin I associated with osmotic challenge in caudal neurosecretory system of the euryhaline flounder, Platichthys flesus. Gen Comp Endocrinol 2019; 277:49-55. [PMID: 30633873 DOI: 10.1016/j.ygcen.2019.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 01/03/2019] [Accepted: 01/08/2019] [Indexed: 11/17/2022]
Abstract
The caudal neurosecretory system (CNSS) is a part of stress response system, a neuroendocrine structure unique to fish. To gain a better understanding of the physiological roles of CNSS in fluid homeostasis, we characterized the tissue distribution of urotensin I (UI) expression in European flounder (Platichthys flesus), analyzed the effect chronic exposure to seawater (SW) or freshwater (FW), transfer from SW to FW, and reverse transfer on mRNA levels of UI, L-type Ca2+ channels and Ca-activated K+ channels transcripts in CNSS. The tissue distribution demonstrated that the CNSS is dominant sites of UI expression, and UI mRNA level in fore brain appeared greater than other non-CNSS tissues. There were no consistent differences in CNSS UI expression or urophysis UI content between SW- and FW-adapted fish in July and September. After transfer from SW to FW, at 8 h CNSS UI expression was significantly increased, but urophysis UI content was no significantly changes. At 24 h transfer from SW to FW, expression of CNSS UI was no apparent change and urophysis UI content was reduced. At 8 h and 24 h after transfer from FW to SW UI expression and urophysis UI content was no significantly effect. The expression of bursting dependent L-type Ca2+ channels and Ca-activated K+ channels in SW-adapted fish significantly decreased compared to those in FW-adapted. However, there were no differences in transfer from SW to FW or from FW to SW at 8 h and 24 h. Thus, these results suggest CNSS UI acts as a modulator in response to osmotic stress and plays important roles in the body fluid homeostasis.
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Affiliation(s)
- Weiqun Lu
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China.
| | - Gege Zhu
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China
| | - Aqin Chen
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China
| | - Xiaoxue Li
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China
| | - Catherine R McCrohan
- Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, M13 9PT, UK
| | - Richard Balment
- Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, M13 9PT, UK
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Lan Z, Zhang W, Xu J, Zhou M, Chen Y, Zou H, Lu W. Modulatory effect of dopamine receptor 5 on the neurosecretory Dahlgren cells of the olive flounder, Paralichthys olivaceus. Gen Comp Endocrinol 2018; 266:67-77. [PMID: 29678723 DOI: 10.1016/j.ygcen.2018.04.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 04/15/2018] [Accepted: 04/16/2018] [Indexed: 02/06/2023]
Abstract
A neuromodulatory role for dopamine has been reported for magnocellular neuroendocrine cells in the mammalian hypothalamus. We examined its potential role as a local intercellular messenger in the neuroendocrine Dahlgren cell population of the caudal neurosecretory system (CNSS) of the euryhaline flounder Paralichthys olivaceus. In vitro application of dopamine (DA) caused an increase in electrical activity (firing frequency, recorded extracellularly) of Dahlgren cells, recruitment of previously silent cells, together with a greater proportion of cells showing phasic (irregular) activity. The dopamine precursor, levodopa (L-DOPA), also increased firing frequency, cell recruitment and enhanced bursting and tonic activity. The effect of dopamine was blocked by the D1, D5 receptor antagonist SCH23390, but not by the D2, D3, D4 receptor antagonist amisulpride. Transcriptome sequencing revealed that all DA receptors (D1, D2, D3, D4, and D5) were present in the flounder CNSS. However, quantitative RT-PCR revealed that D5 receptor mRNA expression was significantly increased in the CNSS following dopamine superfusion. These findings suggest that dopamine may modulate CNSS activity in vivo, and therefore neurosecretory output, through D5 receptors.
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Affiliation(s)
- Zhaohui Lan
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China
| | - Wei Zhang
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China
| | - Jinling Xu
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China
| | - Mo Zhou
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, China
| | - Yingxin Chen
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, China
| | - Huafeng Zou
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China
| | - Weiqun Lu
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China.
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Zou H, Lan Z, Zhou M, Lu W. Promoter methylation and Hoxd4 regulate UII mRNA tissue-specific expression in olive flounder (paralichthys olivaceus). Gen Comp Endocrinol 2018. [PMID: 29522756 DOI: 10.1016/j.ygcen.2018.03.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The peptide urotensin II (UII) mediates multiple physiology effects in mammals and fishes, and UII expression shows a tissue-specific pattern. However the mechanism is still unknown. In the present study high level of UII mRNA was detected in the caudal neurosecretory system (CNSS) of the olive flounder when compared to other tissues. We examined whether epigenetic mechanisms of DNA methylation are involved in UII gene expression. Methylation DNA immune precipitation (MeDIP) assay showed low methylation of UII promoter in CNSS tissue compared with muscle and spinal cord. Methylation of UII promoter was further assessed through bisulphate sequencing analysis. Low level methylation (31%) in CpG island of UII promoter was detected in CNSS tissue, while methylation status in muscle and spinal cord was 89% and 91%, respectively. In addition, high conserved sites of Hoxd4 in UII promoter were found. Activation of Hoxd4 mRNA using transretinoic acid (RA) resulted in 18-fold increase of UII mRNA expression in CNSS and high locomotor activity in medaka, confirming that Hoxd4 is also involved in UII gene transcriptional regulation. Taken together, our data provide the first evidence of the epigenetic mechanism of promoter methylation in transcriptional regulation of UII expression in a tissue-specific manner, and Hoxd4 may also participate in UII gene transcription in flounder.
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Affiliation(s)
- Huafeng Zou
- National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), Shanghai 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education, Shanghai 201306, China
| | - Zhaohui Lan
- National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), Shanghai 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education, Shanghai 201306, China
| | - Mo Zhou
- National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), Shanghai 201306, China
| | - Weiqun Lu
- National Demonstration Center for Experimental Fisheries Science Education (Shanghai Ocean University), Shanghai 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, Shanghai 201306, China.
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8
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Lan Z, Xu J, Wang Y, Lu W. Modulatory effect of glutamate GluR2 receptor on the caudal neurosecretory Dahlgren cells of the olive flounder, Paralichthys olivaceus. Gen Comp Endocrinol 2018; 261:9-22. [PMID: 29355533 DOI: 10.1016/j.ygcen.2018.01.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 01/13/2018] [Accepted: 01/14/2018] [Indexed: 11/26/2022]
Abstract
A neuromodulatory role for glutamate has been reported for magnocellular neuroendocrine cells in mammalian hypothalamus. We examined the potential role of glutamate as a local intercellular messenger in the neuroendocrine Dahlgren cell population of the caudal neurosecretory system (CNSS) in the euryhaline flounder Paralichthys olivaceus. In pharmacological experiments in vitro, glutamate (Glu) caused an increase in electrical activity of Dahlgren cells, recruitment of previously silent cells, together with a greater proportion of cells showing phasic (irregular) activity. The glutamate substrate, glutamine (Gln), led to increased firing frequency, cell recruitment and enhanced bursting activity. The glutamate effect was not blocked by the N-methyl-D-aspartate (NMDA) receptor antagonist MK-801, or the GluR1/GluR3 (AMPA) receptor antagonist IEm1795-2HBr, but was blocked by the broad-spectrum α-amino-3-hydroxy- 5- methyl-4-isoxazo-lepropionic acid (AMPA) receptor antagonist ZK200775. Our transcriptome sequencing study revealed three AMPA receptor (GluR1, GluR2 and GluR3) in the olive flounder CNSS. Quantitative RT-PCR revealed that GluR2 receptor mRNA expression was significant increased following dose-dependent superfusion with glutamate in the CNSS. GluR1 and GluR3 receptor mRNA expression were decreased following superfusion with glutamate. L-type Ca2+ channel mRNA expression had a significant dose-dependent decrease following superfusion with glutamate, compared to the control. In the salinity challenge experiment, acute transfer from SW to FW, GluR2 receptor mRNA expression was significantly higher than the control at 2 h. These findings suggest that GluR2 is one of the mechanisms which can medicate glutamate action within the CNSS, enhancing electrical activity and hence secretory output.
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Affiliation(s)
- Zhaohui Lan
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China
| | - Jinling Xu
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China
| | - Youji Wang
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China
| | - Weiqun Lu
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, China.
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Lu W, Jin Y, Xu J, Greenwood MP, Balment RJ. Molecular characterisation and expression of parathyroid hormone-related protein in the caudal neurosecretory system of the euryhaline flounder, Platichthys flesus. Gen Comp Endocrinol 2017; 249:24-31. [PMID: 28242308 DOI: 10.1016/j.ygcen.2017.02.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 02/21/2017] [Accepted: 02/23/2017] [Indexed: 02/05/2023]
Abstract
Parathyroid hormone-related protein (PTHrP) is a hypercalcemic factor in fish, but the source of circulating PTHrP remains unclear. In this study investigation of the caudal neurosecretory system (CNSS), considered one of major sources of PTHrP in fish, provided valuable insights into this regulatory system. We report pthrpa and pthrpb gene cloning, characterization, expression, and responses to low salinity and hypocalcemia challenge in flounder. The pthrpa and pthrpb precursors, isolated from a European flounder CNSS library, consist of 166 and 192 amino acid residues, respectively, with an overall homology of approximately 59.2%. Both precursors contain a signal peptide and a mature peptide with cleavage and amidation sites. The flounder PTHrPA and PTHrPB peptides share only 41% sequence identity with human PTHrPA. Quantitative PCR analysis demonstrated that the bone and bladder, are respectively major sites of pthrpa and pthrpb expression in flounder. Urophysectomy confirmed the CNSS as a likely contributor to circulating PTHrP peptides. There were no significant differences in CNSS pthrpa and pthrpb mRNA expression or plasma PTHrP levels between seawater (SW) and freshwater (FW)-adapted fish, though plasma total calcium concentrations were higher in FW animals. The intraperitonial administration of EGTA rapidly induced hypocalcemia and concomitant elevation in plasma PTHrP accompanied by increases in both pthrpa and pthrpb expression in the CNSS. Together, these findings support an evolutionary conserved role for PTHrP in the endocrine regulation of calcium.
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Affiliation(s)
- Weiqun Lu
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai 201306, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
| | - Yingying Jin
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China
| | - Jinling Xu
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China
| | - Michael P Greenwood
- Faculty of Life Sciences, University of Manchester, Oxford Road, M13 9PT, United Kingdom
| | - Richard J Balment
- Faculty of Life Sciences, University of Manchester, Oxford Road, M13 9PT, United Kingdom
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Hidalgo MC, Trenzado CE, Furné M, Beltrán A, Manzaneda C, García-Gallego M, Domezain A, Sanz A. Tissue-specific daily variation in the oxidative status of sturgeon (Acipenser naccarii) and rainbow trout (Oncorhynchus mykiss): a comparative study. FISH PHYSIOLOGY AND BIOCHEMISTRY 2017; 43:1105-1115. [PMID: 28293860 DOI: 10.1007/s10695-017-0356-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 02/23/2017] [Indexed: 06/06/2023]
Abstract
The oxidative status is associated with animal lifespan, metabolism, activity and circadian rhythms. The objective of this work is to study the time course of the oxidative status over a daily cycle in the plasma, liver and brain, and the changes in the plasma cortisol levels of sturgeon and trout. The knowledge of daily oxidative status will provide a better understanding of the trout and sturgeon physiology and adequate maintenance and food supply of farmed fish in relation to photoperiod. Superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione transferase, DT-diaphorase activities, lipid peroxidation and cortisol were measured. Our results showed that the antioxidative enzyme activities and lipid peroxidation in the liver of trout and sturgeon changed through the day, with increased levels in lipid peroxidation of liver in the dark period for sturgeon. This could be related to the different activity time in both species, an issue to be taken into account when designing the guidelines of the maintenance of these species in fish farms. On the contrary, there was not clear influence of the daily rhythms on brain oxidative status. The higher efficiency of the antioxidant defences in the brain of sturgeon, which displays less lipid peroxidation and higher antioxidative activity, could be related to its longer life expectancy. The absence of any apparent daily rhythm in the plasma cortisol levels in sturgeon could indicate a lower susceptibility to stress, and that mechanisms involved in cortisol secretion in chondrosteans could be different from that described for teleosteans.
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Affiliation(s)
- M C Hidalgo
- Department of Zoology, School of Science, Campus Fuentenueva, University of Granada, 18071, Granada, Spain.
| | - C E Trenzado
- Department of Cell Biology, School of Science, Campus Fuentenueva, University of Granada, 18071, Granada, Spain
| | - M Furné
- Department of Zoology, School of Science, Campus Fuentenueva, University of Granada, 18071, Granada, Spain
| | - A Beltrán
- Department of Zoology, School of Science, Campus Fuentenueva, University of Granada, 18071, Granada, Spain
| | - C Manzaneda
- Department of Zoology, School of Science, Campus Fuentenueva, University of Granada, 18071, Granada, Spain
| | - M García-Gallego
- Department of Zoology, School of Science, Campus Fuentenueva, University of Granada, 18071, Granada, Spain
| | - A Domezain
- Department of I+D, Piscifactoría "Sierra Nevada" S.L., Riofrío, Granada, Spain
| | - A Sanz
- Department of Zoology, School of Science, Campus Fuentenueva, University of Granada, 18071, Granada, Spain
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11
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Mogi M, Yokoi H, Suzuki T. Analyses of the cellular clock gene expression in peripheral tissue, caudal fin, in the Japanese flounder, Paralichthys olivaceus. Gen Comp Endocrinol 2017; 248:97-105. [PMID: 28249777 DOI: 10.1016/j.ygcen.2017.02.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 01/29/2017] [Accepted: 02/21/2017] [Indexed: 01/03/2023]
Abstract
Understanding the systems for maintaining the circadian rhythms that give organisms the flexibility to adapt to environmental changes is important in both aquaculture and fish chronobiology, because nursery lighting conditions can affect the survival and growth rates of larvae. We previously demonstrated that in flounder, the suprachiasmatic nucleus (SCN) exhibits daily rhythm in per2 expression, in sharp contrast to zebrafish, in which the SCN does not exhibit clear per2 expression rhythm. To examine whether a hierarchy exists in systems that maintain the expression rhythm of peripheral clock genes in flounder, in the present study we analyzed the in vivo and in vitro expression of three clock genes, per2, per1, and cry1, in the caudal fin and the effects of cortisol and melatonin administration on the expression of each clock gene. In vivo, the fin maintained a daily expression rhythm of all three genes, even in 24-h darkness (DD) when shifted from 12-h light:12-h dark (LD) conditions, but fin explants lost the expression rhythm after a short time of tissue culture, even under LD conditions. Cortisol, but not melatonin, significantly upregulated the expression of the three clock genes in fin both in vitro and in vivo. Therefore, we hypothesize that the SCN-pituitary-adrenal cortex pathway plays a role in the oscillation of the peripheral clock in flounder. However, in vivo, peak expression of per2 and cry1 was shifted 2-4h earlier under DD conditions, and their expression was upregulated in response to short exposures to light when larvae were kept under DD conditions. Therefore, we also hypothesize that in addition to the SCN, a light-responsive coordinating factor also functions in photo-entrainment of the peripheral clock in flounder.
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Affiliation(s)
- Makoto Mogi
- Laboratory of Marine Life Science and Genetics, Graduate School of Agricultural Science, Tohoku University, Sendai 980-0845, Japan
| | - Hayato Yokoi
- Laboratory of Marine Life Science and Genetics, Graduate School of Agricultural Science, Tohoku University, Sendai 980-0845, Japan
| | - Tohru Suzuki
- Laboratory of Marine Life Science and Genetics, Graduate School of Agricultural Science, Tohoku University, Sendai 980-0845, Japan.
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Cowan M, Azpeleta C, López-Olmeda JF. Rhythms in the endocrine system of fish: a review. J Comp Physiol B 2017; 187:1057-1089. [DOI: 10.1007/s00360-017-1094-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Revised: 03/20/2017] [Accepted: 04/06/2017] [Indexed: 12/20/2022]
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Luo L, Chen A, Hu C, Lu W. Dynamic expression pattern of corticotropin-releasing hormone, urotensin I and II genes under acute salinity and temperature challenge during early development of zebrafish. FISH PHYSIOLOGY AND BIOCHEMISTRY 2014; 40:1877-1886. [PMID: 25154920 DOI: 10.1007/s10695-014-9975-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 08/13/2014] [Indexed: 06/03/2023]
Abstract
Corticotropin-releasing hormone (CRH), urotensin I (UI) and urotensin II (UII) are found throughout vertebrate species from fish to human. To further understand the role of crh, uI and uII in teleosts during development, we investigated the expression pattern of crh, uI, uIIα and uIIβ genes, and their response to acute salinity and temperature challenge during early development of zebrafish, Danio rerio. The results reveal that crh, uI, uIIα and uIIβ mRNA are detected from 0hpf, and the expression levels increase to a maximum at 6 days post fertilization (dpf), with the exception of uIIα that peak at 5dpf. Exposure of zebrafish embryos and larvae to acute osmotic (30ppt) stress for 15 min failed to modify expression levels of crh, uI, uIIα and uIIβ mRNA from levels in control fish except at 6dpf when uIIα and uIIβ were significantly (P < 0.05) modified. Exposure of embryos and larvae to a cold (18 °C) or hot stress (38 °C) generally down-regulated mRNA levels of crh, uI, uIIα and uIIβ apart from at 3dpf. The results indicate that the contribution of crh, uI, uIIα and uIIβ genes to the stress response in zebrafish may be stressor-specific during early development. Overall, the results from this study provide a basis for further research into the developmental and stressor-specific function of crh, uI, uIIα and uIIβ in zebrafish.
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Affiliation(s)
- Lei Luo
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China
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