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Li J, Chen T, Rao Y, Chen S, Wang B, Chen R, Ren C, Liu L, Yang Y, Yu H, Tang D, Yan A. Suppression of leptin-AI/AII transcripts by insulin in goldfish liver: A fish specific response of leptin under food deprivation. Gen Comp Endocrinol 2019; 283:113240. [PMID: 31394085 DOI: 10.1016/j.ygcen.2019.113240] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 05/18/2019] [Accepted: 08/04/2019] [Indexed: 12/30/2022]
Abstract
Leptin is primarily considered a peripheral satiety hormone and is also found to perform important roles in energy homeostasis in vertebrates ranging from fish to mammals. The liver is a major source of leptin production in teleost fish. Using goldfish as a model, a previous report by our group illustrated the positive regulation of leptin mRNA levels by treatment with the hyperglycemic hormone glucagon, and our present study provided evidence for the negative regulation of hepatic leptin-AI and leptin-AII transcripts through the administration of the hypoglycemic hormone insulin. This study is the first to demonstrate changes in the hepatopancreatic insulin, glucagon, leptin-AI and leptin-AII mRNA levels in goldfish during fasting and refeeding. Insulin was found to be effective in suppressing leptin-AI and leptin-AII transcript levels in goldfish liver via both in vivo intraperitoneal injection and in vitro cell incubation approaches. Only the insulin receptor, not the IGF-I receptor, was involved in insulin-inhibited leptin mRNA level. The suppression of leptin levels by insulin was caused by the activation of MKK3/6/p38MAPK and MEK1/2/Erk1/2 cascades. Insulin treatment could eliminate the stimulation of glucagon on leptin mRNA level. Our study describes the regulation and signal transduction mechanism of insulin on leptin mRNA levels in the goldfish liver, suggesting that the leptin function in fish is speculated to be not only an anorexigenic factor but also a metabolic mediator. This also supports the hypothesis that the poikilothermal fish use a passive survival strategy during the periods of food deprivation, which is mediated by the fish-specifically high leptin levels induced by the cooperation of insulin and glucagon.
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Affiliation(s)
- Jiaxi Li
- School of Life Science and Engineering, School of Stomatology and Medicine, Foshan University, Foshan, China
| | - Ting Chen
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Provincial Key Laboratory of Applied Marine Biology (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Yingzhu Rao
- Institute of Applied Biotechnology, School of Life Science and Technology, Lingnan Normal University, Zhanjiang, China
| | - Shuang Chen
- The Beijing Genomics Institute (BGI), Shenzhen, China
| | - Bin Wang
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Rong Chen
- Institute of Applied Biotechnology, School of Life Science and Technology, Lingnan Normal University, Zhanjiang, China
| | - Chunhua Ren
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Provincial Key Laboratory of Applied Marine Biology (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Lian Liu
- School of Life Science and Engineering, School of Stomatology and Medicine, Foshan University, Foshan, China
| | - Ying Yang
- School of Life Science and Engineering, School of Stomatology and Medicine, Foshan University, Foshan, China
| | - Hui Yu
- School of Life Science and Engineering, School of Stomatology and Medicine, Foshan University, Foshan, China
| | - Dongsheng Tang
- School of Life Science and Engineering, School of Stomatology and Medicine, Foshan University, Foshan, China
| | - Aifen Yan
- School of Life Science and Engineering, School of Stomatology and Medicine, Foshan University, Foshan, China.
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Butt ZD, O'Brien E, Volkoff H. Effects of fasting on the gene expression of appetite regulators in three Characiformes with different feeding habits (Gymnocorymbus ternetzi, Metynnis argenteus and Exodon paradoxus). Comp Biochem Physiol A Mol Integr Physiol 2019; 227:105-115. [DOI: 10.1016/j.cbpa.2018.10.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 10/01/2018] [Indexed: 12/21/2022]
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3
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Ahmad Dar S, Srivastava PP, Varghese T, Irfan Rasool S, Anand G, Gupta S, Gireesh-Babu P, Krishna G. Regulation of compensatory growth by molecular mechanism in Labeo rohita juveniles under different feeding regimes. Gen Comp Endocrinol 2018; 261:89-96. [PMID: 29407384 DOI: 10.1016/j.ygcen.2018.01.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 01/26/2018] [Accepted: 01/27/2018] [Indexed: 11/23/2022]
Abstract
A study was carried out to assess the regulation of compensatory growth under different restriction feeding regimes in Labeo rohita juveniles by the interaction of various feed intake and growth regulating genes. A 60 day feeding trial was conducted with five treatment groups, Control (3% body weight, bw), T1 (alternate days), T2 (0.5% bw), T3 (1% bw) and T4 (2% bw) and feeding was done for first 30 days of the trial. For next 30 days, all the treatment groups were fed at a rate of 3% bw as in the control group. There was significant (p < 0.05) difference in the weight gain among the treatment groups with lowest FCR and highest PER was found in T2 group. Ghrelin gene mRNA levels were upregulated during first 30th days of the trial with highest expression levels in the T2 group. The expression levels of leptin gene mRNA were found significantly different (p < 0.05) among the treatments, which was down-regulated during initial 30 days and upregulated as the experiment progress towards 60th day. The IGF-1 mRNA expression levels were upregulated more in liver compared to the muscle tissue. The results of the study suggest that increased ghrelin levels and decreased leptin levels lead to hyperphagia during the onset of refeeding, which further triggers the compensatory growth in L. rohita. The present study describes the molecular mechanism behind the compensatory growth following a different feed restriction regime in L. rohita which is regulated due to the interaction of different energy homeostasis and growth regulating genes.
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Affiliation(s)
- Showkat Ahmad Dar
- Division of Fish Nutrition, Biochemistry and Physiology, ICAR-Central Institute of Fisheries Education, Mumbai 400061, India
| | - Prem Prakash Srivastava
- Division of Fish Nutrition, Biochemistry and Physiology, ICAR-Central Institute of Fisheries Education, Mumbai 400061, India.
| | - Tincy Varghese
- Division of Fish Nutrition, Biochemistry and Physiology, ICAR-Central Institute of Fisheries Education, Mumbai 400061, India
| | - Sheikh Irfan Rasool
- Division of Fish Nutrition, Biochemistry and Physiology, ICAR-Central Institute of Fisheries Education, Mumbai 400061, India
| | - Garima Anand
- Division of Fish Nutrition, Biochemistry and Physiology, ICAR-Central Institute of Fisheries Education, Mumbai 400061, India
| | - Subodh Gupta
- Division of Fish Nutrition, Biochemistry and Physiology, ICAR-Central Institute of Fisheries Education, Mumbai 400061, India
| | - P Gireesh-Babu
- Division of Fish Genetics and Biotechnology, ICAR-Central Institute of Fisheries Education, Mumbai 400061, India
| | - Gopal Krishna
- ICAR-Central Institute of Fisheries Education, Mumbai 400061, India
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Ohga H, Hirata D, Matsumori K, Kitano H, Nagano N, Yamaguchi A, Matsuyama M. Possible role of the leptin system in controlling puberty in the male chub mackerel, Scomber japonicus. Comp Biochem Physiol A Mol Integr Physiol 2017; 203:159-166. [DOI: 10.1016/j.cbpa.2016.09.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Revised: 09/12/2016] [Accepted: 09/13/2016] [Indexed: 12/25/2022]
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Volkoff H, Estevan Sabioni R, Coutinho LL, Cyrino JEP. Appetite regulating factors in pacu (Piaractus mesopotamicus): Tissue distribution and effects of food quantity and quality on gene expression. Comp Biochem Physiol A Mol Integr Physiol 2016; 203:241-254. [PMID: 27717774 DOI: 10.1016/j.cbpa.2016.09.022] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 09/22/2016] [Accepted: 09/27/2016] [Indexed: 12/22/2022]
Abstract
The pacu Piaractus mesopotamicus is an omnivorous fish considered a promising species for aquaculture. Little is known about the endocrine regulation of feeding in this species. In this study, transcripts for orexin, cocaine and amphetamine regulated transcript (CART), cholecystokinin (CCK) and leptin were isolated in pacu. Orexin, CCK and leptin have widespread mRNA distributions in brain and periphery, CART is limited to the brain. To examine the role of these peptides in the regulation of feeding and energy status, mRNA expression levels were compared between fed and fasted fish and around feeding time. Both orexin and CART brain expressions were affected by fasting and displayed periprandial changes, suggesting a role in both short- and long-term regulation of feeding. CCK intestinal expression decreased in fasted fish and displayed periprandial changes, suggesting CCK acts as a peripheral satiety factor. Leptin was not affected by fasting but displayed periprandial changes, suggesting a role as a short-term regulator. To examine if these peptides are affected by diet, brain and gut expressions were assessed in fish fed with different diets containing soy protein concentrate. Food intake, weight gain and expressions of orexin, CART, CCK and leptin were little affected by replacement of fish protein with soy protein, suggesting that pacu is able to tolerate and grow well with a diet rich in plant material. Overall, our results suggest that orexin, CART, CCK and leptin are involved in the physiology of feeding of pacu and that their expressions are little affected by plant-based diets.
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Affiliation(s)
- Hélène Volkoff
- Department of Biology, Memorial University of Newfoundland, St. John's, NL A1B3X9, Canada; Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL A1B3X9, Canada.
| | - Rafael Estevan Sabioni
- Departamento de Zootecnia, Setor de Piscicultura, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, 13418-900 Piracicaba, SP, Brazil
| | - Luiz Lehmann Coutinho
- Departamento de Zootecnia, Laboratório de Biotecnologia Animal, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, 13418-900 Piracicaba, SP, Brazil
| | - José Eurico Possebon Cyrino
- Departamento de Zootecnia, Setor de Piscicultura, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, 13418-900 Piracicaba, SP, Brazil
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Ohga H, Matsumori K, Kodama R, Kitano H, Nagano N, Yamaguchi A, Matsuyama M. Two leptin genes and a leptin receptor gene of female chub mackerel (Scomber japonicus): Molecular cloning, tissue distribution and expression in different obesity indices and pubertal stages. Gen Comp Endocrinol 2015; 222:88-98. [PMID: 26065595 DOI: 10.1016/j.ygcen.2015.06.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 06/02/2015] [Accepted: 06/03/2015] [Indexed: 12/23/2022]
Abstract
Leptin is a hormone produced by fat cells that regulates the amount of fat stored in the body and conveys nutritional status to the reproductive axis in mammals. In the present study we identified two subtypes of leptin genes (lepa and lepb) and a leptin receptor gene (lepr) from chub mackerel (Scomber japonicus) and there gene expression under different feeding conditions (control and high-feed) and pubertal development stages was analyzed using quantitative real-time PCR. The protein lengths of LepA, LepB and LepR were 161 amino acids (aa), 163 aa and 1149 aa, respectively and both leptin subtypes shared only 15% similarity in aa sequences. In pubertal females, lepa was expressed in the brain, pituitary gland, liver, adipose tissue and ovary; however, in adult (gonadal maturation after the second in the life) females, lepa was expressed only in the liver. lepb was expressed primarily in the brain of all fish tested and was expressed strongly in the adipose tissue of adults. lepr was characterized by expression in the pituitary. The high-feed group showed a high conditioning factor level; unexpectedly, hepatic lepa and brain lepr were significantly more weakly expressed compared with the control-feed group. Furthermore, the expression levels of lepa, lepb and lepr genes showed no significant differences between pre-pubertal and post-pubertal fish. On the other hand, pituitary fshβ and lhβ showed no significant differences between different feeding groups of pre-pubertal fish. In contrast, fshβ and lhβ expressed abundantly in the post-pubertal fish of control feed group. Based on these results, whether leptin plays an important role in the nutritional status and pubertal onset of chub mackerel remains unknown.
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Affiliation(s)
- Hirofumi Ohga
- Laboratory of Marine Biology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan
| | - Kojiro Matsumori
- Laboratory of Marine Biology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan
| | - Ryoko Kodama
- Laboratory of Marine Biology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan
| | - Hajime Kitano
- Fisheries Research Institute of Karatsu, Kyushu University, Saga 847-0132, Japan
| | - Naoki Nagano
- Fisheries Research Institute of Karatsu, Kyushu University, Saga 847-0132, Japan
| | - Akihiko Yamaguchi
- Laboratory of Marine Biology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan
| | - Michiya Matsuyama
- Laboratory of Marine Biology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan.
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7
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Volkoff H. Cloning, tissue distribution and effects of fasting on mRNA expression levels of leptin and ghrelin in red-bellied piranha (Pygocentrus nattereri). Gen Comp Endocrinol 2015; 217-218:20-7. [PMID: 25980684 DOI: 10.1016/j.ygcen.2015.05.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Revised: 04/11/2015] [Accepted: 05/07/2015] [Indexed: 12/26/2022]
Abstract
cDNAs encoding the appetite regulating peptides leptin and ghrelin were isolated in red-bellied piranha (Characiforme, Serrasalmidae) and their mRNA tissue and brain distributions examined. When compared to other fish, the sequences obtained for all peptides were most similar to that of other Characiforme fish and Siluriformes. All peptides were widely expressed within the brain and in several peripheral tissues, including gastrointestinal tract. In order to better understand the role of these peptides in the regulation of feeding of red-bellied piranha, the mRNA expression levels of leptin and ghrelin were examined in both brain and intestine, in fed and 7-day fasted fish. No significant differences in expression were seen in whole brain for either peptide. Within the intestine, there was a decrease in leptin mRNA expression and an increase in ghrelin mRNA expression in fasted fish, compared to fed fish. The results suggest that leptin and ghrelin might play a major role in the regulation of feeding and energy homeostasis of red-bellied piranha and this role might be more prominent in the intestine than in the brain.
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Affiliation(s)
- Hélène Volkoff
- Departments of Biology and Biochemistry, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada.
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8
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Kobayashi Y, Peterson BC, Waldbieser GC. Relationship between expression of muscle-specific uncoupling protein 2 messenger RNA and genetic selection toward growth in channel catfish. Domest Anim Endocrinol 2015; 51:56-64. [PMID: 25528205 DOI: 10.1016/j.domaniend.2014.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 11/10/2014] [Accepted: 11/10/2014] [Indexed: 11/17/2022]
Abstract
This study tested the hypothesis that increased growth in channel catfish is associated with expression of the genes that code for uncoupling proteins (UCP) 2 and 3, members of the mitochondrial channel proteins involved in nutrient sensing and metabolism. The specific objective was to contrast the levels of UCP2 messenger RNA (mRNA) in fast vs slow growing catfish as well as in fed vs fasted catfish. Two distinct UCP2 transcripts were identified and named UCP2a and UCP2b, respectively. Nucleotide and amino acid sequence of catfish UCP2s were highly similar to UCP2 and other UCPs from other fish and mammals (>75%). Expression of UCP2a mRNA was detectable at very low levels in various metabolically active tissues, whereas the expression of UCP2b mRNA was readily detectable in the muscle and heart. In a 21-wk feeding study, fish that grew faster had a greater percent body fat at the end of the study (P < 0.01). Expression of UCP2b mRNA tended to be lower (P < 0.10) in fast growing fish in the middle of the study although levels were similar at the beginning and the end of the study. In the fed vs fasted study, expression of UCP2b mRNA in muscle was increased (P < 0.05) in fish assigned to 30 d of fasting. Our results suggest that, based on the nucleotide and amino acid sequence similarities and tissue mRNA distribution, catfish UCP2b may be the analog to UCP3. Moreover, our results suggest selection toward growth and associated fat accumulation appears to be independent of muscle UCP2b mRNA expression and UCP2b-mediated mechanisms.
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Affiliation(s)
- Y Kobayashi
- Department of Biological Sciences, Fort Hays State University, Hays, KS, USA.
| | - B C Peterson
- USDA/ARS Warmwater Aquaculture Research Unit, Thad Cochran National Warmwater Aquaculture Center, Stoneville, MS, USA
| | - G C Waldbieser
- USDA/ARS Warmwater Aquaculture Research Unit, Thad Cochran National Warmwater Aquaculture Center, Stoneville, MS, USA
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9
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Köprücü S, Algül S. Investigation of the leptin levels in the blood serum of Cyprinus carpio (Linnaeus, 1758) and Capoeta trutta (Heckel, 1843). J Anim Physiol Anim Nutr (Berl) 2014; 99:430-5. [PMID: 25440001 DOI: 10.1111/jpn.12271] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 10/16/2014] [Indexed: 12/18/2022]
Abstract
Leptin is a peptide hormone secreted by adipose tissues in the various teleost fish and vertebrates. Leptin has been suggested to have an important role in a range physiological function, including regulation of food intake, reproduction, immune function, energy expenditure, lipid and carbohydrate metabolism. In this study, leptin levels in the blood serum of Cyprinus carpio and Capoeta trutta were determined. Then the results were compared between two species and between sexes of each species. In addition, leptin levels were also compared with the body weight and length of both C. carpio and C. trutta. Leptin level was analysed using available enzyme-linked immunoassay (ELISA) kit (Rat leptin ELISA kit, catalog no: SK00050-08). Leptin levels showed no significant difference (p > 0.05) that in relation to between two species and between sexes of each species. It has been shown that not significantly correlated when examined correlations between the leptin level in blood serum and body weight (r = 0.192, p = 0.380) or length (r = 0.102, p = 0.644) of C. carpio. Similarly, the correlations between leptin level in blood serum and body weight (r = 0.021, p = 0.959) or length (r = 0.123, p = 0.595) of C. trutta were also not significant.
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Affiliation(s)
- S Köprücü
- Fisheries Faculty, Fırat University, Elazig, Turkey
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10
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Yuan D, Wang T, Zhou C, Lin F, Chen H, Wu H, Wei R, Xin Z, Li Z. Leptin and cholecystokinin in Schizothorax prenanti: molecular cloning, tissue expression, and mRNA expression responses to periprandial changes and fasting. Gen Comp Endocrinol 2014; 204:13-24. [PMID: 24852347 DOI: 10.1016/j.ygcen.2014.05.013] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Revised: 05/06/2014] [Accepted: 05/08/2014] [Indexed: 12/15/2022]
Abstract
In the present study, full-length cDNA sequences of leptin and cholecystokinin (CCK) were cloned from Schizothorax prenanti (S. prenanti), and applied real-time quantitative PCR to characterize the tissue distribution, and appetite regulatory effects of leptin and CCK in S. prenanti. The S. prenanti leptin and CCK full-length cDNA sequences were 1121 bp and 776 bp in length, encoding the peptide of 171 and 123 amino acid residues, respectively. Tissue distribution analysis showed that leptin mRNA was mainly expressed in the liver of S. prenanti. CCK was widely expressed, with the highest levels of expression in the hypothalamus, myelencephalon, telencephalon and foregut of S. prenanti. The CCK mRNA expression was highly elevated after feeding, whereas the leptin mRNA expression was not affected by single meal. These results suggested that CCK is a postprandial satiety signal in S. prenanti, but leptin might not be. In present study, leptin and CCK gene expression were both decreased after fasting and increased after refeeding, which suggested leptin and CCK might be involved in regulation of appetite in S. prenanti. This study provides an essential groundwork to further elucidate the appetite regulatory systems of leptin and CCK in S. prenanti as well as in other teleosts.
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Affiliation(s)
- Dengyue Yuan
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, China
| | - Tao Wang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, China
| | - Chaowei Zhou
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, China
| | - Fangjun Lin
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, China
| | - Hu Chen
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, China
| | - Hongwei Wu
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, China
| | - Rongbin Wei
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, China
| | - Zhiming Xin
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, China
| | - Zhiqiong Li
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, China.
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11
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Tinoco AB, Nisembaum LG, de Pedro N, Delgado MJ, Isorna E. Leptin expression is rhythmic in brain and liver of goldfish (Carassius auratus). Role of feeding time. Gen Comp Endocrinol 2014; 204:239-47. [PMID: 24932715 DOI: 10.1016/j.ygcen.2014.06.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Revised: 03/28/2014] [Accepted: 06/05/2014] [Indexed: 12/01/2022]
Abstract
Daily rhythms of feeding regulators are currently arousing research interest due to the relevance of the temporal harmony of endocrine regulators for growth and welfare in vertebrates. However, it is unknown the leptin circadian pattern in fish. The aim of this study is to investigate if leptin (gLep-aI and gLep-aII) expression is rhythmic in goldfish (Carassius auratus) liver and brain, and if such rhythms are driven by feeding time through a food entrainable oscillator. Fish maintained under 12-h light:12-h dark photoperiod and a scheduled feeding time showed 24-h locomotor activity and glycaemia rhythms. Moreover, hepatic gLep-aI and brain gLep-aI and gLep-aII expression were rhythmic with different daily profiles, showing a postprandial increase of leptin expression in the liver but not in the brain. Under constant light and different feeding regimes (scheduled fed at 10:00, 22:00 or randomly fed), feeding time synchronized daily rhythms in locomotor activity, glycaemia and clock gene expression (gPer1a, gPer3 and gCry3), but the rhythmic expression of hepatic gLep-aI and brain gLep-aII only remained in fed fish at 10:00. In summary, daily rhythms of leptin expression in goldfish are differently regulated at central and peripheral level, and they are not directly driven by clock genes. The role of food entrained oscillators on leptin expression rhythms in fish remains to be demonstrated.
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Affiliation(s)
- Ana B Tinoco
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Laura G Nisembaum
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Nuria de Pedro
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - María J Delgado
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Esther Isorna
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de Madrid, 28040 Madrid, Spain.
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12
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MacDonald LE, Alderman SL, Kramer S, Woo PTK, Bernier NJ. Hypoxemia-induced leptin secretion: a mechanism for the control of food intake in diseased fish. J Endocrinol 2014; 221:441-55. [PMID: 24741070 DOI: 10.1530/joe-13-0615] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Leptin is a potent anorexigen, but little is known about the physiological conditions under which this cytokine regulates food intake in fish. In this study, we characterized the relationships between food intake, O2-carrying capacity, liver leptin-A1 (lep-a1) gene expression, and plasma leptin-A1 in rainbow trout infected with a pathogenic hemoflagellate, Cryptobia salmositica. As lep gene expression is hypoxia-sensitive and Cryptobia-infected fish are anemic, we hypothesized that Cryptobia-induced anorexia is mediated by leptin. A 14-week time course experiment revealed that Cryptobia-infected fish experience a transient 75% reduction in food intake, a sharp initial drop in hematocrit and hemoglobin levels followed by a partial recovery, a transient 17-fold increase in lep-a1 gene expression, and a sustained increase in plasma leptin-A1 levels. In the hypothalamus, peak anorexia was associated with decreases in mRNA levels of neuropeptide Y (npy) and cocaine- and amphetamine-regulated transcript (cart), and increases in agouti-related protein (agrp) and pro-opiomelanocortin A2 (pomc). In contrast, in non-infected fish pair-fed to infected animals, lep-a1 gene expression and plasma levels did not differ from those of non-infected satiated fish. Pair-fed fish were also characterized by increases in hypothalamic npy and agrp, no changes in pomc-a2, and a reduction in cart mRNA expression. Finally, peak infection was characterized by a significant positive correlation between O2-carrying capacity and food intake. These findings show that hypoxemia, and not feed restriction, stimulates leptin-A1 secretion in Cryptobia-infected rainbow trout and suggest that leptin contributes to anorexia by inhibiting hypothalamic npy and stimulating pomc-a2.
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Affiliation(s)
- Lauren E MacDonald
- Department of Integrative BiologyUniversity of Guelph, 50 Stone Road East, Guelph, Ontario, Canada N1G 2W1
| | - Sarah L Alderman
- Department of Integrative BiologyUniversity of Guelph, 50 Stone Road East, Guelph, Ontario, Canada N1G 2W1
| | - Sarah Kramer
- Department of Integrative BiologyUniversity of Guelph, 50 Stone Road East, Guelph, Ontario, Canada N1G 2W1
| | - Patrick T K Woo
- Department of Integrative BiologyUniversity of Guelph, 50 Stone Road East, Guelph, Ontario, Canada N1G 2W1
| | - Nicholas J Bernier
- Department of Integrative BiologyUniversity of Guelph, 50 Stone Road East, Guelph, Ontario, Canada N1G 2W1
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Gong N, Einarsdottir IE, Johansson M, Björnsson BT. Alternative splice variants of the rainbow trout leptin receptor encode multiple circulating leptin-binding proteins. Endocrinology 2013; 154:2331-40. [PMID: 23645152 DOI: 10.1210/en.2012-2082] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In mammals, leptin (Lep) binding proteins (LepBPs) derived from Lep receptor (LepR) gene or protein bind most of the circulating Lep, but to date, information on LepBPs in nonmammalian vertebrate classes is lacking. This study details the characterization of multiple LepBPs in rainbow trout (Oncorhynchus mykiss), an early poikilothermic vertebrate, and presents the complete coding sequences for 3 of them. Size-exclusion chromatography and cross-linking assay identified plasma proteins bound to Lep ranging from 70 to 100 kDa. LepBPs were isolated from plasma by affinity chromatography, and their binding specificity was assessed by a competitive binding assay. A RIA for LepBPs indicates that plasma LepBP levels decline after fasting for 3 weeks. Immunoblotting of LepBPs using antibodies against different LepR epitopes shows that the LepBPs are indeed LepR isoforms. The alternatively spliced LepR transcripts (LepR(S1-3)) that include only the extracellular segment transcribe the 90-kDa LepBP1, the 80-kDa LepBP2, and the 70-kDa LepBP3, respectively. LepR(S1) generally has lower expression than the long-form LepR in most tissues. LepR(S2) is primarily expressed in adipose tissue, whereas LepR(S3) is expressed abundantly in brain and spleen, and moderately in liver and gills. The mRNA levels of hepatic LepR(S3) increase after 2 weeks of fasting. This study demonstrates a mechanism in fish for the generation of LepBPs that differs from that seen in mammals and indicates that the physiologic action of Lep in these poikilothermic vertebrates can be modulated, both centrally and peripherally, by the differentiated, tissue-specific expression of multiple LepBPs.
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Affiliation(s)
- Ningping Gong
- Fish Endocrinology Laboratory, Department of Biological and Environmental Sciences, University of Gothenburg, S-40590 Gothenburg, Sweden.
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Tinoco AB, Nisembaum LG, Isorna E, Delgado MJ, de Pedro N. Leptins and leptin receptor expression in the goldfish (Carassius auratus). Regulation by food intake and fasting/overfeeding conditions. Peptides 2012; 34:329-35. [PMID: 22342497 DOI: 10.1016/j.peptides.2012.02.001] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 02/01/2012] [Accepted: 02/01/2012] [Indexed: 01/05/2023]
Abstract
Leptin is a hormone involved in feeding and body weight regulation in vertebrates, but the relationship between energy status and leptin has not been clearly established in fish. The aim of this study was to investigate in a teleost, the goldfish (Carassius auratus), the tissue expression pattern of two leptins (gLep-aI and gLep-aII) and leptin receptor (gLepR); and the effect of feeding on expression of these genes. Leptin system expression in goldfish was firstly analyzed in fish under overfeeding (2 weeks) or fasting (1 week), and secondly, at different postfeeding times (0, 3, 6, 9 and 12h). Goldfish has two Lep-a paralog genes, gLep-aI was widely expressed in central and peripheral tissues, whereas gLep-aII was preferentially expressed in brain. This different distribution pattern of leptins suggests that they can play different physiological roles in goldfish. The gLepR mRNA was ubiquitous expressed, with the highest expression in the telencephalon and hypothalamus. No significant differences in the leptin system expression were found among control, overfed and fasting groups, suggesting an apparent lack of correlation between nutritional status and leptin system in goldfish. Hepatic expression of gLep-aI significantly increased 9h after feeding time, while hypothalamic leptin system expression did not change after feeding. In summary, leptin in goldfish could signal short-term changes in food intake, as postprandial satiety, but seems to be independent of fasting/overfeeding conditions in this teleost. The widespread distribution of leptins and leptin receptor in goldfish strongly supports that this hormone may have pleitropic actions in fish.
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Affiliation(s)
- Ana Belén Tinoco
- Dpto. Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense, 28040 Madrid, Spain
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