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Zhang Y, Hu J, Lu P, Yang R, Liang XF, Liu L. Addition of α-ketoglutaric acid (AKG) reduces deamination in Chinese perch (Siniperca chuatsi) fed with fermented soybean meal as a substitute for fishmeal. FISH PHYSIOLOGY AND BIOCHEMISTRY 2024; 50:989-1002. [PMID: 38321345 DOI: 10.1007/s10695-024-01312-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 01/28/2024] [Indexed: 02/08/2024]
Abstract
To alleviate amino acid imbalances in fermented soybean meal as a replacement for fishmeal feeds, this study evaluated the effects of adding lysine (Lys), methionine (Met), and α-ketoglutaric acid (AKG) to fermented soybean meals for Chinese perch. Chinese perch (34 ± 3 g) were fed five diets for 66 days (fishmeal as the protein source of the basal diet [FM]; fermented soybean meal as a substitute for 30% fishmeal in the soybean meal diet [FSM]; addition of crystalline Lys and Met [AA]; addition of α-ketoglutaric acid [AKG]; and simultaneous addition of crystalline Lys, Met, and AKG [BA] to the soybean meal diet). At the end of the feeding trial, the FSM group had the highest feeding rate and the lowest weight gain rate among all the groups. The FM group had the highest protein retention and the lowest feed efficiency among the groups. The mRNA transcription level of genes related to the AMP-activating protein (AMPK) signaling pathway and amino acid response (AAR) signaling pathway (lkb1, atf4, and gcn2) were highest in the AA group (P < 0.05) but lower in the AKG and BA groups. In the AKG group, the mRNA transcription level of the gluconeogenesis pathway-related gene (pepck and g6pase) was significantly higher than that in the other four groups, but the mRNA transcription level of genes related to amino acid catabolism (gdh and ampd) was lower. Among all the groups, the FSM group had the lowest mRNA transcription level of genes associated with the mammalian target of rapamycin (mTOR) signaling pathway (mtor and s6k). These findings imply that the feeding rate of Chinese perch in the fermented soybean meal group was the highest, but the protein retention was the lowest, while the addition of Lys, Met, and AKG improved protein retention. In conclusion, the addition of AKG to fermented soybean meal as a fishmeal substitute reduced amino acid deamination, enhanced gluconeogenesis, and increased protein deposition, which contributed to the growth of Chinese perch, alleviated amino acid imbalances, and improved the feed utilization of Chinese perch.
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Affiliation(s)
- Yufei Zhang
- College of Fisheries, Chinese Perch Research Center, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, No.1, Shizishan Street, Hongshan District, Wuhan, 430070, Hubei Province, People's Republic of China
| | - Jiacheng Hu
- College of Fisheries, Chinese Perch Research Center, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, No.1, Shizishan Street, Hongshan District, Wuhan, 430070, Hubei Province, People's Republic of China
| | - Peisong Lu
- College of Fisheries, Chinese Perch Research Center, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, No.1, Shizishan Street, Hongshan District, Wuhan, 430070, Hubei Province, People's Republic of China
| | - Ru Yang
- College of Fisheries, Chinese Perch Research Center, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, No.1, Shizishan Street, Hongshan District, Wuhan, 430070, Hubei Province, People's Republic of China
| | - Xu-Fang Liang
- College of Fisheries, Chinese Perch Research Center, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, No.1, Shizishan Street, Hongshan District, Wuhan, 430070, Hubei Province, People's Republic of China
| | - Liwei Liu
- College of Fisheries, Chinese Perch Research Center, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, No.1, Shizishan Street, Hongshan District, Wuhan, 430070, Hubei Province, People's Republic of China.
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, 410081, Hunan, People's Republic of China.
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Du R, Shi X, Chen F, Wang L, Liang H, Hu G. Corticotropin-Releasing Hormone: A Novel Stimulator of Somatolactin in Teleost Pituitary Cells. Cells 2023; 12:2770. [PMID: 38132090 PMCID: PMC10741825 DOI: 10.3390/cells12242770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/29/2023] [Accepted: 11/29/2023] [Indexed: 12/23/2023] Open
Abstract
Corticotropin-releasing hormone (CRH) is known for its crucial role in the stress response system, which could induce pituitary adrenocorticotropic hormone (ACTH) secretion to promote glucocorticoid release in the adrenal gland. However, little is known about other pituitary actions of CRH in teleosts. Somatolactin is a fish-specific hormone released from the neurointermediate lobe (NIL) of the posterior pituitary. A previous study has reported that ACTH was also located in the pituitary NIL region. Interestingly, our present study found that CRH could significantly induce two somatolactin isoforms' (SLα and SLβ) secretion and synthesis in primary cultured grass carp pituitary cells. Pharmacological analysis further demonstrated that CRH-induced pituitary somatolactin expression was mediated by the AC/cAMP/PKA, PLC/IP3/PKC, and Ca2+/CaM/CaMK-II pathways. Finally, transcriptomic analysis showed that both SLα and SLβ should play an important role in the regulation of lipid metabolism in primary cultured hepatocytes. These results indicate that CRH is a novel stimulator of somatolactins in teleost pituitary cells, and somatolactins may participate in the stress response by regulating energy metabolism.
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Affiliation(s)
- Ruixin Du
- Hubei Hongshan Laboratory, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (R.D.); (X.S.); (F.C.); (L.W.)
| | - Xuetao Shi
- Hubei Hongshan Laboratory, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (R.D.); (X.S.); (F.C.); (L.W.)
| | - Feng Chen
- Hubei Hongshan Laboratory, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (R.D.); (X.S.); (F.C.); (L.W.)
| | - Li Wang
- Hubei Hongshan Laboratory, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (R.D.); (X.S.); (F.C.); (L.W.)
| | - Hongwei Liang
- Hubei Hongshan Laboratory, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (R.D.); (X.S.); (F.C.); (L.W.)
- Key Lab of Freshwater Biodiversity Conservation Ministry of Agriculture, Yangtze River Fisheries Research Institute, The Chinese Academy of Fisheries Sciences, Wuhan 430223, China
| | - Guangfu Hu
- Hubei Hongshan Laboratory, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (R.D.); (X.S.); (F.C.); (L.W.)
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3
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Zou JM, Zhu QS, Liang H, Lu HL, Liang XF, He S. Lysine Deprivation Regulates Npy Expression via GCN2 Signaling Pathway in Mandarin Fish ( Siniperca chuatsi). Int J Mol Sci 2022; 23:ijms23126727. [PMID: 35743178 PMCID: PMC9223478 DOI: 10.3390/ijms23126727] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 06/11/2022] [Accepted: 06/13/2022] [Indexed: 11/18/2022] Open
Abstract
Regulation of food intake is associated with nutrient-sensing systems and the expression of appetite neuropeptides. Nutrient-sensing systems generate the capacity to sense nutrient availability to maintain energy and metabolism homeostasis. Appetite neuropeptides are prominent factors that are essential for regulating the appetite to adapt energy status. However, the link between the expression of appetite neuropeptides and nutrient-sensing systems remains debatable in carnivorous fish. Here, with intracerebroventricular (ICV) administration of six essential amino acids (lysine, methionine, tryptophan, arginine, phenylalanine, or threonine) performed in mandarin fish (Siniperca chuatsi), we found that lysine and methionine are the feeding-stimulating amino acids other than the reported valine, and found a key appetite neuropeptide, neuropeptide Y (NPY), mainly contributes to the regulatory role of the essential amino acids on food intake. With the brain cells of mandarin fish cultured in essential amino acid deleted medium (lysine, methionine, histidine, valine, or leucine), we showed that only lysine deprivation activated the general control nonderepressible 2 (GCN2) signaling pathway, elevated α subunit of eukaryotic translation initiation factor 2 (eIF2α) phosphorylation, increased activating transcription factor 4 (ATF4) protein expression, and finally induced transcription of npy. Furthermore, pharmacological inhibition of GCN2 and eIF2α phosphorylation signaling by GCN2iB or ISRIB, effectively blocked the transcriptional induction of npy in lysine deprivation. Overall, these findings could provide a better understanding of the GCN2 signaling pathway involved in food intake control by amino acids.
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Affiliation(s)
- Jia-Ming Zou
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan 430070, China; (J.-M.Z.); (Q.-S.Z.); (H.L.); (H.-L.L.)
- Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China
| | - Qiang-Sheng Zhu
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan 430070, China; (J.-M.Z.); (Q.-S.Z.); (H.L.); (H.-L.L.)
- Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China
| | - Hui Liang
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan 430070, China; (J.-M.Z.); (Q.-S.Z.); (H.L.); (H.-L.L.)
- Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China
| | - Hai-Lin Lu
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan 430070, China; (J.-M.Z.); (Q.-S.Z.); (H.L.); (H.-L.L.)
- Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China
| | - Xu-Fang Liang
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan 430070, China; (J.-M.Z.); (Q.-S.Z.); (H.L.); (H.-L.L.)
- Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China
- Correspondence: (X.-F.L.); (S.H.); Tel.: +86-15007113487 (X.-F.L.); +86-18672986332 (S.H.); Fax: +86-027-8728-2114 (X.-F.L.); +86-027-8728-2113 (S.H.)
| | - Shan He
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan 430070, China; (J.-M.Z.); (Q.-S.Z.); (H.L.); (H.-L.L.)
- Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China
- Correspondence: (X.-F.L.); (S.H.); Tel.: +86-15007113487 (X.-F.L.); +86-18672986332 (S.H.); Fax: +86-027-8728-2114 (X.-F.L.); +86-027-8728-2113 (S.H.)
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4
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Neuropeptide Y in Spotted Scat (Scatophagus Argus), Characterization and Functional Analysis towards Feed Intake Regulation. FISHES 2022. [DOI: 10.3390/fishes7030111] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Neuropeptide Y (Npy) is an intricate neuropeptide regulating numerous physiological processes. It is a highly conserved peptide known to improve feed intake in many vertebrates, including fishes. To enlighten the mechanism of Npy in spotted scat feed intake control, we cloned and identified the Npy cDNA sequence. We further examined its expression in some tissues and explored its expression effects at different time frames (hours and days). Here, we discovered that spotted scat Npy comprised a 300 bp open reading frame (ORF) and a 99 amino acid sequence. Npy was identified to be expressed in all tissues examined. Using in situ hybridization examination, we proved that npy has a wide expression in the brain of the spotted scat. Furthermore, the expression of npy in the hypothalamus significantly increased one hour after feeding (p < 0.05). Further, it was revealed that npy expression significantly increased in fish that were fasted for up to 5 days and significantly increased after refeeding from the 8th to the 10th day. This suggests that Npy is an orexigenic peptide, and hence, it increases food intake and growth in the spotted scat. Additionally, results from in vitro and in vivo experiments revealed that Npy locally interacts with other appetite-regulating peptides in the spotted scat hypothalamus. This research aimed to set a fundamental study in developing the feed intake regulation, improving growth and reproduction, which is significant to the aquaculture industry of the spotted scat.
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Watanabe K, Konno N, Nakamachi T, Matsuda K. Intracerebroventricular administration of α-melanocyte-stimulating hormone (α-MSH) enhances thigmotaxis and induces anxiety-like behavior in the goldfish Carassius auratus. Peptides 2021; 145:170623. [PMID: 34375685 DOI: 10.1016/j.peptides.2021.170623] [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: 06/23/2021] [Revised: 08/04/2021] [Accepted: 08/05/2021] [Indexed: 12/23/2022]
Abstract
α-Melanocyte-stimulating hormone (α-MSH) is a body pigmentation-regulating hormone secreted from the intermediate lobe of the pituitary in vertebrates. It is also produced in the brain, and acts as an anorexigenic neuropeptide involved in feeding regulation. In rodents, intracerebroventricular (ICV) administration of α-MSH has been shown to affect not only feeding behavior, but also psychomotor activity. However, there is still no information regarding the psychophysiological effects of α-MSH on behavior in fish. Therefore, we examined the effect of synthetic α-MSH on psychomotor activity in goldfish. Since this species prefers the edge to the central area of a tank, we used this as a preference test for assessing psychomotor activity. When α-MSH was administered ICV at 1 and 10 pmol g-1 body weight (BW), the time spent in the edge area of a tank was prolonged at 10 pmol g-1 BW. However, α-MSH at these doses did not affect locomotor activity. The action of α-MSH mimicked those of FG-7142 (a central-type benzodiazepine receptor (CBR) inverse agonist with an anxiogenic effect) at 10 pmol g-1 BW and melanotan II (a melanocortin 4 receptor (MC4R) agonist) at 50 pmol g-1 BW, whereas ICV administration of tofisopam (a CBR agonist with an anxiolytic effect) at 10 pmol g-1 BW prolonged the time spent in the central area. The anxiogenic-like effect of α-MSH was abolished by treatment with the MC4R antagonist HS024 at 50 pmol g-1 BW. These data indicate that α-MSH affects psychomotor activity in goldfish, and exerts an anxiogenic-like effect via the MC4R-signaling pathway.
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Affiliation(s)
- Keisuke Watanabe
- Laboratory of Regulatory Biology, Graduate School of Innovative Life Sciences, University of Toyama, Toyama, 930-8555, Japan
| | - Norifumi Konno
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555, Japan; Laboratory of Regulatory Biology, Faculty of Science, Academic Assembly, University of Toyama, Toyama, 930-8555, Japan
| | - Tomoya Nakamachi
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555, Japan; Laboratory of Regulatory Biology, Faculty of Science, Academic Assembly, University of Toyama, Toyama, 930-8555, Japan
| | - Kouhei Matsuda
- Laboratory of Regulatory Biology, Graduate School of Innovative Life Sciences, University of Toyama, Toyama, 930-8555, Japan; Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555, Japan; Laboratory of Regulatory Biology, Faculty of Science, Academic Assembly, University of Toyama, Toyama, 930-8555, Japan.
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6
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Amano M, Amiya N, Fukushima K, Hagio H, Yamamoto N, Sakakura Y. Effects of crowding stress on the hypothalamo-pituitary-interrenal axis of the self-fertilizing fish, Kryptolebias marmoratus. Comp Biochem Physiol A Mol Integr Physiol 2021; 264:111110. [PMID: 34737084 DOI: 10.1016/j.cbpa.2021.111110] [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: 09/29/2021] [Revised: 10/29/2021] [Accepted: 10/29/2021] [Indexed: 11/26/2022]
Abstract
We tested whether crowding stress affects the hypothalamo-pituitary-interrenal (HPI) axis of the self-fertilizing fish, Kryptolebias marmoratus, which is known to be aggressive in the laboratory conditions but sometimes found as a group from a single land crab burrow in the wild. The projection of corticotropin-releasing hormone (CRH) neurons to the adrenocorticotropic hormone (ACTH) cells in the pituitary was confirmed by dual-label immunohistochemistry; CRH-immunoreactive (ir) fibers originating from cell bodies located in the lateral tuberal nucleus (NLT) of the hypothalamus were observed to project to ACTH-ir cells in the rostral pars distalis of the pituitary. Then, fish were reared solitary or in pairs for 14 days, and the number of CRH-ir cell bodies in the NLT of the hypothalamus and cortisol levels in the body without head region were compared. The number of CRH-ir cell bodies and cortisol levels were significantly higher in paired fish. These results indicate that crowding stress affects the HPI axis in K. marmoratus which thrive in small burrows with limited water volume.
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Affiliation(s)
- Masafumi Amano
- School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa 252-0373, Japan.
| | - Noriko Amiya
- School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa 252-0373, Japan
| | - Keisuke Fukushima
- School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa 252-0373, Japan
| | - Hanako Hagio
- Institute for Advanced Research, Nagoya University, Nagoya, Aichi 464-8601, Japan; Laboratory of Fish Biology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Naoyuki Yamamoto
- Laboratory of Fish Biology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Yoshitaka Sakakura
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki 852-8521, Japan
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The Roles of Neuropeptide Y ( Npy) and Peptide YY ( Pyy) in Teleost Food Intake: A Mini Review. Life (Basel) 2021; 11:life11060547. [PMID: 34200824 PMCID: PMC8230510 DOI: 10.3390/life11060547] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/05/2021] [Accepted: 06/08/2021] [Indexed: 12/12/2022] Open
Abstract
Neuropeptide Y family (NPY) is a potent orexigenic peptide and pancreatic polypeptide family comprising neuropeptide Y (Npy), peptide YYa (Pyya), and peptide YYb (Pyyb), which was previously known as peptide Y (PY), and tetrapod pancreatic polypeptide (PP), but has not been exhaustively documented in fish. Nonetheless, Npy and Pyy to date have been the key focus of countless research studies categorizing their copious characteristics in the body, which, among other things, include the mechanism of feeding behavior, cortical neural activity, heart activity, and the regulation of emotions in teleost. In this review, we focused on the role of neuropeptide Y gene (Npy) and peptide YY gene (Pyy) in teleost food intake. Feeding is essential in fish to ensure growth and perpetuation, being indispensable in the aquaculture settings where growth is prioritized. Therefore, a better understanding of the roles of these genes in food intake in teleost could help determine their feeding regime, regulation, growth, and development, which will possibly be fundamental in fish culture.
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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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Aardema ML, Stiassny MLJ, Alter SE. Genomic Analysis of the Only Blind Cichlid Reveals Extensive Inactivation in Eye and Pigment Formation Genes. Genome Biol Evol 2020; 12:1392-1406. [PMID: 32653909 PMCID: PMC7502198 DOI: 10.1093/gbe/evaa144] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2020] [Indexed: 12/21/2022] Open
Abstract
Trait loss represents an intriguing evolutionary problem, particularly when it occurs across independent lineages. Fishes in light-poor environments often evolve “troglomorphic” traits, including reduction or loss of both pigment and eyes. Here, we investigate the genomic basis of trait loss in a blind and depigmented African cichlid, Lamprologus lethops, and explore evolutionary forces (selection and drift) that may have contributed to these losses. This species, the only known blind cichlid, is endemic to the lower Congo River. Available evidence suggests that it inhabits deep, low-light habitats. Using genome sequencing, we show that genes related to eye formation and pigmentation, as well as other traits associated with troglomorphism, accumulated inactivating mutations rapidly after speciation. A number of the genes affected in L. lethops are also implicated in troglomorphic phenotypes in Mexican cavefish (Astyanax mexicanus) and other species. Analysis of heterozygosity patterns across the genome indicates that L. lethops underwent a significant population bottleneck roughly 1 Ma, after which effective population sizes remained low. Branch-length tests on a subset of genes with inactivating mutations show little evidence of directional selection; however, low overall heterozygosity may reduce statistical power to detect such signals. Overall, genome-wide patterns suggest that accelerated genetic drift from a severe bottleneck, perhaps aided by directional selection for the loss of physiologically expensive traits, caused inactivating mutations to fix rapidly in this species.
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Affiliation(s)
- Matthew L Aardema
- Department of Biology, Montclair State University.,Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, New York
| | - Melanie L J Stiassny
- Department of Ichthyology, American Museum of Natural History, New York, New York
| | - S Elizabeth Alter
- Department of Ichthyology, American Museum of Natural History, New York, New York.,The Graduate Center, City University of New York.,Department of Biology, York College/The City University of New York
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Qi J, Tang N, Wu Y, Chen H, Wang S, Wang B, Xu S, Wang M, Zhang X, Chen D, Zhou B, Li Z. The transcripts of CRF and CRF receptors under fasting stress in Dabry's sturgeon (Acipenser dabryanus Dumeril). Gen Comp Endocrinol 2019; 280:200-208. [PMID: 31075270 DOI: 10.1016/j.ygcen.2019.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 05/06/2019] [Accepted: 05/06/2019] [Indexed: 12/16/2022]
Abstract
Dabry's sturgeon (Acipenser dabryanus Dumeril, 1868) belongs to Sturgeon and is distributed throughout the mainstream of the upper Yangtze River. While there is little research onphysiological mechanism of Dabry's sturgeon, such as feeding regulation by the CRF system. At present, CRF is thought to regulate feeding via CRF receptors (CRF-Rs) in several mammals, but relatively few studies of CRF and feeding exist in teleosts. Herein, the transcripts of CRF and CRF-Rs under fasting stress in Dabry's sturgeon (Acipenser dabryanus Dumeril) have been explored. A full length Dabry's sturgeon CRF cDNA of 953 bp was identified, which contained a 447 bp open reading frame (ORF). A partial CRF-R1 cDNA of 1053 bp and CRF-R2 cDNA of 906 bp corresponding to the coding sequences (CDS) was obtained. In addition, analysis of the tissue distribution of CRF and CRF-Rs mRNAs revealed they were widely distributed in the central and peripheral nervous systems. Furthermore, periprandial (preprandial and postprandial), fasting, and re-feeding experiments revealed CRF mRNA was significantly increased 1 h and 3 h after feeding and CRF and CRF-Rs transcripts were significantly decreased after 10 days fasting, and significantly increased on re-feeding on day 10. These results suggest that CRF and CRF-Rs might regulate feeding by acting as satiety factors.
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Affiliation(s)
- Jinwen Qi
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Ni Tang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Yuanbin Wu
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Hu Chen
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Shuyao Wang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Bin Wang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Shaoqi Xu
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Mei Wang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Xin Zhang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China; The Key Laboratory of Mariculture, Ministry of Education, Fisheries College, Ocean University of China, 5# Yushan Road, Qingdao, Shandong, China
| | - Defang Chen
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Bo Zhou
- Fisheries Institute, Sichuan Academy of Agricultural Sciences, 156# Gaozhuang Bridge Community, Yibin, Sichuan, China.
| | - Zhiqiong Li
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China.
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11
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Nielsen SV, Frausing M, Henriksen PG, Beedholm K, Baatrup E. The Psychoactive Drug Escitalopram Affects Foraging Behavior in Zebrafish (Danio rerio). ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2019; 38:1902-1910. [PMID: 31389079 DOI: 10.1002/etc.4474] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 02/20/2019] [Accepted: 05/08/2019] [Indexed: 06/10/2023]
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are psychoactive pharmaceuticals that have been detected intact in natural waters globally. Laboratory experiments have reported that several SSRIs inhibit fish foraging behavior, but data for the SSRI escitalopram are lacking. The objectives of the present study were to determine whether escitalopram affects feeding behavior in zebrafish and whether possible sex differences exist. We exposed female and male zebrafish (Danio rerio) to 0.00, 0.10, and 1.50 µg/L of escitalopram in flow-through tanks for a 3-wk exposure period. We used a video tracking system with high temporal and spatial resolution to collect data on zebrafish swimming patterns in test tanks containing a food source. The results show a more pronounced effect of escitalopram in males compared with females. At the assumed most environmentally relevant concentration (0.10 µg/L), male average feeding time/visit and maximum feeding duration were significantly reduced by 27 and 42%, respectively. In addition, male total feeding duration was also significantly reduced (by 73%) at the highest concentration (1.50 µg/L). In females, only the maximum feeding duration was significantly reduced (by 41%) in the 0.10 µg/L treatment group. Hence, we reject our initial hypothesis that female feeding behavior is more vulnerable to escitalopram. There was no effect of escitalopram on length or weight among the experimental groups. The present study demonstrates that escitalopram, like other SSRIs, can inhibit fish foraging behavior and therefore potentially disturb natural food chains. Finally, our study suggests that SSRIs can both be sex and behavior specific. Environ Toxicol Chem 2019;38:1902-1910. © 2019 SETAC.
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Affiliation(s)
| | - Marie Frausing
- Zoophysiology Research, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | | | - Kristian Beedholm
- Zoophysiology Research, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Erik Baatrup
- Zoophysiology Research, Department of Bioscience, Aarhus University, Aarhus, Denmark
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12
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Hatef A, Unniappan S. Metabolic hormones and the regulation of spermatogenesis in fishes. Theriogenology 2019; 134:121-128. [PMID: 31167155 DOI: 10.1016/j.theriogenology.2019.05.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Accepted: 05/26/2019] [Indexed: 02/08/2023]
Abstract
Metabolic hormones play essential regulatory roles in many biological processes, including morphogenesis, growth, and reproduction through the maintenance of energy balance. Various metabolic hormones originally discovered in mammals, including ghrelin, leptin, and nesfatin-1 have been identified and characterized in fish. However, physiological roles of these metabolic hormones in regulating reproduction are largely unknown in fishes, especially in males. While the information available is restricted, this review attempts to summarize the main findings on the roles of metabolic peptides on the reproductive system in male fishes with an emphasis on testicular development and spermatogenesis. Specifically, the primary goal is to review the physiological interactions between hormones that regulate reproduction and hormones that regulate metabolism as a critical determinant of testicular function. A brief introduction to the localization of metabolic hormones in fish testis is also provided. Besides, the consequences of fasting and food deprivation on testicular development and sperm quality will be discussed with a focus on interactions between metabolic and reproductive hormones.
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Affiliation(s)
- Azadeh Hatef
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada
| | - Suraj Unniappan
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada.
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13
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Magliozzi L, Maselli V, Almada F, Di Cosmo A, Mollo E, Polese G. Effect of the algal alkaloid caulerpin on neuropeptide Y (NPY) expression in the central nervous system (CNS) of Diplodus sargus. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2019; 205:203-210. [DOI: 10.1007/s00359-019-01322-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 02/18/2019] [Accepted: 02/21/2019] [Indexed: 11/24/2022]
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14
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Zhang X, Qi J, Tang N, Wang S, Wu Y, Chen H, Tian Z, Wang B, Chen D, Li Z. Intraperitoneal injection of nesfatin-1 primarily through the CCK-CCK1R signal pathway affects expression of appetite factors to inhibit the food intake of Siberian sturgeon (Acipenser baerii). Peptides 2018; 109:14-22. [PMID: 30261207 DOI: 10.1016/j.peptides.2018.09.008] [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: 05/21/2018] [Revised: 09/20/2018] [Accepted: 09/21/2018] [Indexed: 12/13/2022]
Abstract
Nesfatin-1 is an 82-amino acid protein derived from nucleobindin 2 (NUCB2), which could inhibit food intake in fish and mammals. However, the neuroendocrine mechanism of nesfatin-1 in animal appetite regulation is unclear. To explore the feeding mechanism of nesfatin-1 in Siberian sturgeon (Acipenser baerii), intraperitoneal injections of nesfatin-1 and sulfated cholecystokinin octapeptide (CCK8), Lorglumide (CCK1R selective antagonist), or LY 225,910 (CCK2R selective antagonist) were performed. Co-injection of nesfatin-1 and CCK8 synergistically significantly decreased the food intake in 1 h. Lorglumide reversed the anorectic effect of nesfatin-1, but LY 225,910 had no effect. Moreover, Lorglumide could also reverse the expressions of appetite factors including nucb2, cck, unc3, cart, apelin, pyy, and npy induced by nesfatin-1 in the brain, stomach, and liver, while LY 225,910 partially reversed these changes. These results indicate that nesfatin-1 inhibits the appetite of Siberian sturgeon mainly through the CCK-CCK1R signaling pathway.
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Affiliation(s)
- Xin Zhang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China; The Key Laboratory of Mariculture, Ministry of Education, Fisheries College, Ocean University of China, 5# Yushan Road, Qingdao, Shandong, China
| | - Jinwen Qi
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Ni Tang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Shuyao Wang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Yuanbing Wu
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Hu Chen
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Zhengzhi Tian
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Bin Wang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Defang Chen
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Zhiqiong Li
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China.
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15
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Zhao Y, Long L, Xu W, Campbell RF, Large EE, Greene JS, McGrath PT. Changes to social feeding behaviors are not sufficient for fitness gains of the Caenorhabditis elegans N2 reference strain. eLife 2018; 7:38675. [PMID: 30328811 PMCID: PMC6224195 DOI: 10.7554/elife.38675] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 10/15/2018] [Indexed: 12/15/2022] Open
Abstract
The standard reference Caenorhabditis elegans strain, N2, has evolved marked behavioral changes in social feeding behavior since its isolation from the wild. We show that the causal, laboratory-derived mutations in two genes, npr-1 and glb-5, confer large fitness advantages in standard laboratory conditions. Using environmental manipulations that suppress social/solitary behavior differences, we show the fitness advantages of the derived alleles remained unchanged, suggesting selection on these alleles acted through pleiotropic traits. Transcriptomics, developmental timing, and food consumption assays showed that N2 animals mature faster, produce more sperm, and consume more food than a strain containing ancestral alleles of these genes regardless of behavioral strategies. Our data suggest that the pleiotropic effects of glb-5 and npr-1 are a consequence of changes to O2 -sensing neurons that regulate both aerotaxis and energy homeostasis. Our results demonstrate how pleiotropy can lead to profound behavioral changes in a popular laboratory model. Why do humans walk on two feet? And what makes us smarter than our ape ancestors? The answers to these questions, and countless others about the particular traits of any number of species, is often said to be natural selection – a process where genes that ensure the survival of a species are favored of others. But it is not always the answer. Other evolutionary forces, such as random changes to the frequency of certain gene variants, restrictions on the development of a certain trait and pleiotropy (where one gene influences other, seemingly unrelated traits) can also cause differences between species. Designing experiments to test whether a trait difference is due to natural selection or other factors is notoriously difficult. However, the humble nematode worm, Caenorhabditis elegans, has proven to be particularly useful in this respect. One subtype or strain of C. elegans with certain changes to its genes is used internationally as a ‘reference strain’, to ensure results between labs are comparable. This strain, N2, has been bred in the laboratory for hundreds of generations, isolated from its wild counterparts. N2 shows several differences in behavior from the wildtype, including its feeding habits. Wild C. elegans tend to feed together socially, whereas N2 prefers to feed alone. In 1998 and 2009, researchers – including some involved in the current study – have identified the genetic modifications responsible for this change in behavior. Now, Zhao et al. set out to determine whether this was due to natural selection, and if so, was there a benefit to solitary feeding in laboratory conditions that was driving this genetic change? Zhao et al. found that the genetic changes in the N2 strain gave the worms a considerable advantage in the artificial environment. However, experiments to modify the conditions the animals grew in revealed that the solitary feeding habits were not necessary for the fitness advantage. In other words, the changes in feeding habits were a symptom of the genetic changes that gave N2 a selective advantage, but they were not the cause. In other words, the changes in feeding behavior were not a result of natural selection, but rather of pleiotropy. The findings highlight that not every change in a trait is down to natural selection and must therefore be put to the test. With declining costs of DNA sequencing, researchers can now easily identify genes and regions of DNA that are likely to be under selection. However, they must be careful before leaping to the conclusion that behavioral differences linked to genetic changes are adaptive. In addition, the findings show that the laboratories relying on N2 as a model organism should be aware that the strain has evolved fundamental differences in its brain connections compared with the wildtype.
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Affiliation(s)
- Yuehui Zhao
- Department of Biological Sciences, Georgia Institute of Technology, Atlanta, United States
| | - Lijiang Long
- Department of Biological Sciences, Georgia Institute of Technology, Atlanta, United States
| | - Wen Xu
- Department of Biological Sciences, Georgia Institute of Technology, Atlanta, United States
| | - Richard F Campbell
- Department of Biological Sciences, Georgia Institute of Technology, Atlanta, United States
| | - Edward E Large
- Department of Biological Sciences, Georgia Institute of Technology, Atlanta, United States
| | | | - Patrick T McGrath
- Department of Biological Sciences, Georgia Institute of Technology, Atlanta, United States.,Department of Physics, Georgia Institute of Technology, Atlanta, United States.,Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, United States
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16
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Zhang X, Wang S, Chen H, Tang N, Qi J, Wu Y, Hao J, Tian Z, Wang B, Chen D, Li Z. The inhibitory effect of NUCB2/nesfatin-1 on appetite regulation of Siberian sturgeon (Acipenser baerii Brandt). Horm Behav 2018; 103:111-120. [PMID: 29940158 DOI: 10.1016/j.yhbeh.2018.06.008] [Citation(s) in RCA: 15] [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] [Received: 04/28/2018] [Revised: 06/18/2018] [Accepted: 06/20/2018] [Indexed: 12/19/2022]
Abstract
Since NUCB2 was discovered, the information about NUCB2/nesfatin-1 in appetite regulation in both mammals and teleost has been still limited. The present study aims to determine the effects of nesfatin-1 on food intake and to explore the appetite mechanism in Siberian sturgeon. In this study, nucb2 cDNA sequence of 1571 bp was obtained, and the mRNA expression of nucb2 was abundant in brain and liver. Levels of nucb2 were appreciably increased in brain after feeding 1 and 3 h, while significantly decreased within fasting 15 days. Except for fasting 1 day, the expression pattern of nucb2 in the liver was similar to the brain. Acute intraperitoneal (i.p.) injection of nesfatin-1 inhibited the food intake during 0-1 h in a dose-dependent manner and 50 or 100 ng/g BW nesfatin-1 significantly decreased the cumulative food intake during 3 h. The daily food intake and cumulative food intake were remarkably reduced post chronic (7 days) i.p. injection. Moreover, chronic i.p. injection of nesfatin-1 affected the expression of appetite factors including cart, apelin and pyy in the brain, stomach and liver with the consistent pattern of change, while the levels of cck, ucn3 and nucb2 in these have different patterns. This study demonstrates that nesfatin-1 acts as a satiety factor in reducing the short-term and long-term food intake of Siberian sturgeon. Therefore, the data suggesting nesfatin-1 inhibits the appetite through different signal pathways in the central and peripheral endocrine systems of Siberian sturgeon.
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Affiliation(s)
- Xin Zhang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China; The Key Laboratory of Mariculture, Ministry of Education, Fisheries College, Ocean University of China, 5# Yushan Road, Qingdao, Shandong, China
| | - Shuyao Wang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Hu Chen
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Ni Tang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Jinwen Qi
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Yuanbing Wu
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Jin Hao
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Zhengzhi Tian
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Bin Wang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Defang Chen
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China
| | - Zhiqiong Li
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, Sichuan, China.
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17
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Snigirov S, Sylantyev S. GABA A receptors activate fish feeding behaviour via two distinct functional pathways. ACTA ACUST UNITED AC 2018; 221:jeb.170514. [PMID: 29191862 DOI: 10.1242/jeb.170514] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 11/27/2017] [Indexed: 11/20/2022]
Abstract
Benzodiazepines, acting through ionotropic receptors of γ-aminobutyric acid (GABAA receptors, GABAR), have been shown to modify feeding behaviour and increase appetite in humans and non-human subjects. However, the cellular and molecular mechanisms that underlie connected short-term behavioural fluctuations are still unclear. In the present study, we used Carassius gibelio (Prussian carp) as a model organism to research the impact of scantily explored benzodiazepine phenazepam (PNZ) on feeding behaviour and the related molecular mechanisms of PNZ action at single-cell and single-receptor levels. We found that the feeding activity of C. gibelio is under control of GABARs via two distinct mechanisms: orthosteric (triggered by GABA binding site) and allosteric (triggered by benzodiazepine binding site). PNZ displayed clear stimulatory effects on both mechanisms in a GABA-dependent manner. In addition, orthosteric and allosteric effects were found to be partially competitive, which leads to complex behavioural repercussions of conjoint effects of GABAR ligands.
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Affiliation(s)
- Sergey Snigirov
- Biological Department, Odessa National Mechnikov University, 2 Shampanskiy Lane, Odessa 65058, Ukraine
| | - Sergiy Sylantyev
- Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK .,Department for Clinical and Experimental Epilepsy, Institute of Neurology, University College London, Queen Square House, Queen Square, London WC1N 3BG, UK
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18
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CCK reduces the food intake mainly through CCK1R in Siberian sturgeon (Acipenser baerii Brandt). Sci Rep 2017; 7:12413. [PMID: 28963554 PMCID: PMC5622057 DOI: 10.1038/s41598-017-12646-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 09/13/2017] [Indexed: 11/14/2022] Open
Abstract
To explore the effect of CCK on food intake in Siberian sturgeon, cck cDNA sequence of 1005 bp was obtained, and cck mRNA possessed the highest expression in brain. The expressions of cck were significantly increased after feeding 1 and 3 h, while displaying significant decrease after fasting within 15 days in brain and duodenum. Re-feeding for 3 days induced cck level returned to basic level. Acute i.p. injection experiment showed 100 and 200 ng/g BW CCK8 inhibited the food intake in 0–1 h together with the cumulative food intake within 3 h. 7 days chronic i.p. injection of 100 and 200 ng/g BW CCK8, both daily food intake and cumulative food intake were significantly decreased. In addition, chronic i.p injection of CCK8 induced the expression of feeding related factors changes including cck, ucn3, cart, apelin, pyy and npy in respective organization. Moreover, as revealed by the results, Lorglumide, the CCK1R selective antagonist, effectively reversed the inhibitory effects of CCK8 on food intake and the levels of feeding related factors. On the other hand, LY 225910, the CCK2R selective antagonist, partially reversed these effects. These results indicate CCK is a satiety factor inhibits the feeding of Siberian sturgeon primarily through CCK1R.
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19
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Matsuda K, Matsumura K, Shimizu SS, Nakamachi T, Konno N. Neuropeptide Y-Induced Orexigenic Action Is Attenuated by the Orexin Receptor Antagonist in Bullfrog Larvae. Front Neurosci 2017; 11:176. [PMID: 28420957 PMCID: PMC5378779 DOI: 10.3389/fnins.2017.00176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 03/16/2017] [Indexed: 11/13/2022] Open
Abstract
In bullfrog larvae at the pre- and pro-metamorphic stages, feeding behavior is regulated by appetite factors such as orexigenic peptides. In fact, food intake is enhanced by intracerebroventricular (ICV) administration of neuropeptide Y (NPY) and orexin A. Using goldfish, our previous study indicated that the orexigenic action of NPY is mediated by orexin A, suggesting the functional interaction between the two. However, there is little information about whether the action of orexin A mediates the orexigenic action of NPY in bullfrog larvae. Therefore, we examined the effect of the orexin receptor antagonist, SB334867 on the orexigenic action of NPY in larvae. The stimulatory effect of ICV injection of NPY at 10 pmol/g body weight (BW) on food intake was abolished by treatment with SB334867 at 60 pmol/g BW. These results suggest that, in bullfrog larvae, there is a neuronal relationship between the NPY and orexin systems, and that the orexigenic action of NPY is mediated by the orexin A-induced orexigenic action.
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Affiliation(s)
- Kouhei Matsuda
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of ToyamaToyama, Japan.,Laboratory of Regulatory Biology, Graduate School of Innovative Life Sciences, University of ToyamaToyama, Japan
| | - Kairi Matsumura
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of ToyamaToyama, Japan
| | - Syun-Suke Shimizu
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of ToyamaToyama, Japan
| | - Tomoya Nakamachi
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of ToyamaToyama, Japan
| | - Norifumi Konno
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of ToyamaToyama, Japan
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20
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Shimoyama S, Inoue T, Kashima M, Agata K. Multiple Neuropeptide-Coding Genes Involved in Planarian Pharynx Extension. Zoolog Sci 2016; 33:311-9. [PMID: 27268986 DOI: 10.2108/zs150170] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Planarian feeding behavior involves three steps: moving toward food, extending the pharynx from their planarian's ventral side after arriving at the food, and ingesting the food through the pharynx. Although pharynx extension is a remarkable behavior, it remains unknown what neuronal cell types are involved in its regulation. To identify neurons involved in regulating pharynx extension, we quantitatively analyzed pharynx extension and sought to identify these neurons by RNA interference (RNAi) and in situ hybridization. This assay, when performed using planarians with amputation of various body parts, clearly showed that the head portion is indispensable for inducing pharynx extension. We thus tested the effects of knockdown of brain neurons such as serotonergic, GABAergic, and dopaminergic neurons by RNAi, but did not observe any effects on pharynx extension behavior. However, animals with RNAi of the Prohormone Convertase 2 (PC2, a neuropeptide processing enzyme) gene did not perform the pharynx extension behavior, suggesting the possible involvement of neuropeptide(s in the regulation of pharynx extension. We screened 24 neuropeptide-coding genes, analyzed their functions by RNAi using the pharynx extension assay system, and identified at least five neuropeptide genes involved in pharynx extension. These was expressed in different cells or neurons, and some of them were expressed in the brain, suggesting complex regulation of planarian feeding behavior by the nervous system.
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Affiliation(s)
- Seira Shimoyama
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
| | - Takeshi Inoue
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
| | - Makoto Kashima
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
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21
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Volkoff H. The Neuroendocrine Regulation of Food Intake in Fish: A Review of Current Knowledge. Front Neurosci 2016; 10:540. [PMID: 27965528 PMCID: PMC5126056 DOI: 10.3389/fnins.2016.00540] [Citation(s) in RCA: 168] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 11/07/2016] [Indexed: 12/14/2022] Open
Abstract
Fish are the most diversified group of vertebrates and, although progress has been made in the past years, only relatively few fish species have been examined to date, with regards to the endocrine regulation of feeding in fish. In fish, as in mammals, feeding behavior is ultimately regulated by central effectors within feeding centers of the brain, which receive and process information from endocrine signals from both brain and peripheral tissues. Although basic endocrine mechanisms regulating feeding appear to be conserved among vertebrates, major physiological differences between fish and mammals and the diversity of fish, in particular in regard to feeding habits, digestive tract anatomy and physiology, suggest the existence of fish- and species-specific regulating mechanisms. This review provides an overview of hormones known to regulate food intake in fish, emphasizing on major hormones and the main fish groups studied to date.
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Affiliation(s)
- Helene Volkoff
- Departments of Biology and Biochemistry, Memorial University of NewfoundlandSt. John's, NL, Canada
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22
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Culbert BM, Gilmour KM. Rapid recovery of the cortisol response following social subordination in rainbow trout. Physiol Behav 2016; 164:306-13. [PMID: 27317163 DOI: 10.1016/j.physbeh.2016.06.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 05/29/2016] [Accepted: 06/13/2016] [Indexed: 12/20/2022]
Abstract
Rainbow trout (Oncorhynchus mykiss) confined in pairs form social hierarchies in which distinctive behavioural and physiological phenotypes distinguish dominant from subordinate fish. In particular, subordinate fish are characterized by inhibition of behaviours such as feeding and activity, by low growth rates, and by chronic elevation of circulating glucocorticoid stress hormone (cortisol) concentrations. To evaluate the ability of trout to recover from chronic social stress, pairs of fish were allowed to interact for 4d, and subordinate fish were then separated from dominant fish. Recovery was assessed using behavioural (position in the tank, latency to feed, and food consumed) and physiological (plasma cortisol and glucose concentrations, liver glycogen content, hepatosomatic index, specific growth rate, and gall bladder mass) indices. During 48 or 96h of recovery from the 4d interaction period, only plasma cortisol and glucose levels of subordinates returned to baseline values consistent with those of dominant and sham trout (fish that were handled like paired fish but housed singly). All other physiological variables failed to recover, likely owing to the absence of behavioural recovery, including continued inhibition of food intake even following separation from the dominant fish. Whereas subordinate fish exhibited an attenuated cortisol response to an acute netting stressor, 'recovered' subordinates mounted a cortisol response that was equivalent to those of dominant and sham fish. However, 'recovered' subordinates that were paired with a socially naïve conspecific were unable to achieve non-subordinate status. Collectively, these results indicate that recovery of the cortisol response precedes behavioural recovery from social subordination.
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Affiliation(s)
- Brett M Culbert
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
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Zhang J, Sun P, Yang F, Kong T, Zhang R. Tributyltin disrupts feeding and energy metabolism in the goldfish (Carassius auratus). CHEMOSPHERE 2016; 152:221-8. [PMID: 26971175 DOI: 10.1016/j.chemosphere.2016.02.127] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Revised: 02/28/2016] [Accepted: 02/29/2016] [Indexed: 05/22/2023]
Abstract
Tributyltin (TBT) can induce obesogen response. However, little is known about the adverse effects of TBT on food intake and energy metabolism. The present study was designed to investigate the effects of TBT, at environmental concentrations of 2.44 and 24.4 ng/L (1 and 10 ng/L as Sn), on feeding and energy metabolism in goldfish (Carassius auratus). After exposure for 54 d, TBT increased the weight gain and food intake in fish. The patterns of brain neuropeptide genes expression were in line with potential orexigenic effects, with increased expression of neuropeptide Y and apelin, and decreased expression of pro-opiomelanocortin, ghrelin, cocaine and amphetamine-regulated transcript, and corticotropin-releasing factor. Interestingly, the energy metabolism indicators (oxygen consumption, ammonia exertion and swimming activity) and the serum thyroid hormones were all significantly increased at the 2.44 ng/L TBT group in fish. However, no changes of energy metabolism indicators or a decrease of thyroid hormones was found at the 24.4 ng/L TBT group, which indicated a complex disrupting effect on metabolism of TBT. In short, TBT can alter feeding and energy metabolism in fish, which might promote the obesogenic responses.
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Affiliation(s)
- Jiliang Zhang
- Henan Open Laboratory of Key Subjects of Environmental and Animal Products Safety, College of Animal Science and Technology, Henan University of Science and Technology, Henan, China.
| | - Ping Sun
- Henan Open Laboratory of Key Subjects of Environmental and Animal Products Safety, College of Animal Science and Technology, Henan University of Science and Technology, Henan, China
| | - Fan Yang
- Henan Open Laboratory of Key Subjects of Environmental and Animal Products Safety, College of Animal Science and Technology, Henan University of Science and Technology, Henan, China
| | - Tao Kong
- Henan Open Laboratory of Key Subjects of Environmental and Animal Products Safety, College of Animal Science and Technology, Henan University of Science and Technology, Henan, China
| | - Ruichen Zhang
- Henan Open Laboratory of Key Subjects of Environmental and Animal Products Safety, College of Animal Science and Technology, Henan University of Science and Technology, Henan, China
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Food intake inhibition in rainbow trout induced by activation of serotonin 5-HT2C receptors is associated with increases in POMC, CART and CRF mRNA abundance in hypothalamus. J Comp Physiol B 2016; 186:313-21. [PMID: 26832922 DOI: 10.1007/s00360-016-0961-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 01/05/2016] [Accepted: 01/15/2016] [Indexed: 11/27/2022]
Abstract
In rainbow trout, the food intake inhibition induced by serotonin occurs through 5-HT2C and 5-HT1A receptors, though the mechanisms involved are still unknown. Therefore, we assessed if a direct stimulation of 5-HT2C and 5-HT1A serotonin receptors (resulting in decreased food intake in rainbow trout), affects gene expression of neuropeptides involved in the control of food intake, such as pro-opiomelanocortin (POMC), cocaine- and amphetamine-regulated transcript (CART), corticotrophin releasing factor (CRF), and agouti-related peptide (AgRP). In a first set of experiments, the injection of the 5-HT2C receptor agonists MK212 (60 μg kg(-1) icv) and WAY 161503 (1 mg kg(-1) ip), and of the 5-HT1A receptor agonist 8-OH-DPAT (1 mg kg(-1) ip and 30 μg kg(-1) icv) induced food intake inhibition. In a second set of experiments, we observed that the injection of MK212 or WAY 161503 (1 and 3 mg kg(-1)) significantly increased hypothalamic POMC mRNA abundance. CART mRNA abundance in hypothalamus was enhanced by treatment with MK212 and unaffected by WAY 161503. The administration of the 5-HT1A receptor agonist 8-OH-DPAT did not induce any significant variation in the hypothalamic POMC or CART mRNA levels. CRF mRNA abundance was only affected by MK212 that increased hypothalamic values. Finally, hypothalamic AgRP mRNA abundance was only evaluated with the agonist 5-HT2C MK212 resulting in no significant effects. The results show that the reduction in food intake mediated by 5-HT2C receptors is associated with increases in hypothalamic POMC, CART and CRF mRNA abundance.
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Maximino C, Silva RXDC, da Silva SDNS, Rodrigues LDSDS, Barbosa H, de Carvalho TS, Leão LKDR, Lima MG, Oliveira KRM, Herculano AM. Non-mammalian models in behavioral neuroscience: consequences for biological psychiatry. Front Behav Neurosci 2015; 9:233. [PMID: 26441567 PMCID: PMC4561806 DOI: 10.3389/fnbeh.2015.00233] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 08/18/2015] [Indexed: 01/04/2023] Open
Abstract
Current models in biological psychiatry focus on a handful of model species, and the majority of work relies on data generated in rodents. However, in the same sense that a comparative approach to neuroanatomy allows for the identification of patterns of brain organization, the inclusion of other species and an adoption of comparative viewpoints in behavioral neuroscience could also lead to increases in knowledge relevant to biological psychiatry. Specifically, this approach could help to identify conserved features of brain structure and behavior, as well as to understand how variation in gene expression or developmental trajectories relates to variation in brain and behavior pertinent to psychiatric disorders. To achieve this goal, the current focus on mammalian species must be expanded to include other species, including non-mammalian taxa. In this article, we review behavioral neuroscientific experiments in non-mammalian species, including traditional "model organisms" (zebrafish and Drosophila) as well as in other species which can be used as "reference." The application of these domains in biological psychiatry and their translational relevance is considered.
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Affiliation(s)
- Caio Maximino
- Laboratório de Neurociências e Comportamento, Departamento de Morfologia e Ciências Fisiológicas, Campus VIII – Marabá, Universidade do Estado do ParáMarabá, Brazil
| | - Rhayra Xavier do Carmo Silva
- Laboratório de Neurociências e Comportamento, Departamento de Morfologia e Ciências Fisiológicas, Campus VIII – Marabá, Universidade do Estado do ParáMarabá, Brazil
| | - Suéllen de Nazaré Santos da Silva
- Laboratório de Neurociências e Comportamento, Departamento de Morfologia e Ciências Fisiológicas, Campus VIII – Marabá, Universidade do Estado do ParáMarabá, Brazil
| | - Laís do Socorro dos Santos Rodrigues
- Laboratório de Neurociências e Comportamento, Departamento de Morfologia e Ciências Fisiológicas, Campus VIII – Marabá, Universidade do Estado do ParáMarabá, Brazil
| | - Hellen Barbosa
- Laboratório de Neurociências e Comportamento, Departamento de Morfologia e Ciências Fisiológicas, Campus VIII – Marabá, Universidade do Estado do ParáMarabá, Brazil
| | - Tayana Silva de Carvalho
- Universität Duisburg-EssenEssen, Germany
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do ParáBelém, Brazil
| | - Luana Ketlen dos Reis Leão
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do ParáBelém, Brazil
| | - Monica Gomes Lima
- Laboratório de Neurociências e Comportamento, Departamento de Morfologia e Ciências Fisiológicas, Campus VIII – Marabá, Universidade do Estado do ParáMarabá, Brazil
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do ParáBelém, Brazil
| | - Karen Renata Matos Oliveira
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do ParáBelém, Brazil
| | - Anderson Manoel Herculano
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do ParáBelém, Brazil
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López JM, Sanz-Morello B, González A. Organization of the orexin/hypocretin system in the brain of two basal actinopterygian fishes, the cladistians Polypterus senegalus and Erpetoichthys calabaricus. Peptides 2014; 61:23-37. [PMID: 25169954 DOI: 10.1016/j.peptides.2014.08.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 08/19/2014] [Accepted: 08/19/2014] [Indexed: 01/12/2023]
Abstract
Cladistians are primitive actinopterygian fishes mostly neglected in neuroanatomical studies. In the present study, the detailed neuroanatomical distribution of orexin (hypocretin)-like immunoreactive (OX-ir) cell bodies and fibers was analyzed in the brain of two species representative of the two extant genera of cladistians. Antibodies against mammalian orexin-A and orexin-B peptides were used. Simultaneous detection of orexins with neuropeptide Y (NPY), tyrosine hydroxylase (TH), and serotonin (5-HT) was used to establish accurately the topography of the orexin system and to evaluate the possible interactions with NPY and monoaminergic systems. A largely common pattern of OX-ir distribution in the two cladistian species was observed. Most OX-ir cells were located in the suprachiasmatic nucleus and tuberal hypothalamus, whereas scarce cells were observed in the posterior tubercle. In addition, a population of OX-ir cells was found in the preoptic area only in Polypterus and some cells also contained TH. The observed widespread distribution of OX-ir fibers was especially abundant in the retrobulbar area, subpallial areas, preoptic area, suprachiasmatic nucleus, tuberal hypothalamic area, prethalamus, thalamus, pretectum, optic tectum, and tegmentum. Low innervation was found in relation to monoaminergic cell groups, whereas a high NPY innervation was observed in all OX-ir cell groups. These relationships would represent the anatomical substrate for the functional interdependence between these systems. The organization of the orexin system in cladistians revealed a pattern largely consistent with those reported for all studied groups of vertebrates, suggesting that the primitive organization of this peptidergic system occurred in the common ancestor of gnathostome vertebrates.
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Affiliation(s)
- Jesús M López
- Department of Cell Biology, Faculty of Biology, University Complutense, 28040 Madrid, Spain
| | - Berta Sanz-Morello
- Department of Cell Biology, Faculty of Biology, University Complutense, 28040 Madrid, Spain
| | - Agustín González
- Department of Cell Biology, Faculty of Biology, University Complutense, 28040 Madrid, Spain.
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Wang T, Zhou C, Yuan D, Lin F, Chen H, Wu H, Wei R, Xin Z, Liu J, Gao Y, Li Z. Schizothorax prenanti corticotropin-releasing hormone (CRH): molecular cloning, tissue expression, and the function of feeding regulation. FISH PHYSIOLOGY AND BIOCHEMISTRY 2014; 40:1407-1415. [PMID: 24696302 DOI: 10.1007/s10695-014-9935-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 03/26/2014] [Indexed: 06/03/2023]
Abstract
Corticotropin-releasing hormone (CRH) is a potent mediator of endocrine, autonomic, behavioral, and immune responses to stress. For a better understanding of the structure and function of the CRH gene and to study its effect on feeding regulation in cyprinid fish, the cDNA of the CRH gene from the brain of Schizothorax prenanti was cloned and sequenced. The full-length CRH cDNA consisted of 1,046 bp with an open reading frame of 489 bp encoding a protein of 162 amino acids. Real-time quantitative PCR analyses revealed that CRH was widely expressed in central and peripheral tissues. In particular, high expression level of CRH was detected in brain. Furthermore, CRH mRNA expression was examined in different brain regions, especially high in hypothalamus. In addition, there was no significant change in CRH mRNA expression in fed group compared with the fasted group in the S. prenanti hypothalamus during short-term fasting. However, CRH gene expression presented significant decrease in the hypothalamus in fasted group compared with the fed group (P < 0.05) on day 7; thereafter, re-feeding could lead to a significant increase in CRH mRNA expression in fasted group on day 9. The results suggest that the CRH may play a critical role in feeding regulation in S. prenanti.
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Affiliation(s)
- Tao Wang
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, 625014, China
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28
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Shimizu S, Nakamachi T, Konno N, Matsuda K. Orexin A enhances food intake in bullfrog larvae. Peptides 2014; 59:79-82. [PMID: 25064815 DOI: 10.1016/j.peptides.2014.07.013] [Citation(s) in RCA: 8] [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] [Received: 06/24/2014] [Revised: 07/15/2014] [Accepted: 07/15/2014] [Indexed: 10/25/2022]
Abstract
Orexin is a potent orexigenic peptide implicated in appetite regulation in rodents. However, except for teleost fish, the involvement of orexin in the regulation of feeding in non-mammalian vertebrates has not been well studied. Anuran amphibian larvae feed and grow during the pre- and prometamorphic stages. Therefore, orexigenic factors seem to play important roles in growing larvae. Indeed, our recent studies have demonstrated that neuropeptide Y and ghrelin exert orexigenic actions in bullfrog larvae during the prometamorphic stages. In this study, we examined the effect of intracerebroventricular (ICV) administration of synthetic orexin A on food intake in bullfrog larvae at the prometamorphic stages. Food intake was significantly increased by ICV administration of orexin A (at 6 pmol/g BW) during a 15-min observation period. The orexigenic action of orexin A at 6 pmol/g BW was blocked by treatment with an orexin receptor antagonist, SB334867, at 60 pmol/g BW. These results indicate that orexin A acts as an orexigenic factor in bullfrog larvae.
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Affiliation(s)
- Shunsuke Shimizu
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan
| | - Tomoya Nakamachi
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan
| | - Norifumi Konno
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan
| | - Kouhei Matsuda
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan; Laboratory of Regulatory Biology, Graduate School of Innovative Life Science, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan.
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29
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Nakamachi T, Shibata H, Sakashita A, Iinuma N, Wada K, Konno N, Matsuda K. Orexin A enhances locomotor activity and induces anxiogenic-like action in the goldfish, Carassius auratus. Horm Behav 2014; 66:317-23. [PMID: 24937437 DOI: 10.1016/j.yhbeh.2014.06.004] [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: 03/07/2014] [Revised: 06/05/2014] [Accepted: 06/06/2014] [Indexed: 12/11/2022]
Abstract
Orexin acts as an orexigenic factor for the regulation of appetite and rhythmicity in rodents. In goldfish, intracerebroventricular (ICV) administration of orexin A has been shown to affect not only food intake, but also locomotor activity. However, as there is still no information regarding the effect of orexin A on emotional behavior in goldfish, we investigated the effect of orexin A on psychomotor activity in this species. Intracerebroventricular administration of synthetic orexin A at 2 and 4pmol/g body weight (BW) enhanced locomotor activity, and this enhancement by orexin A at 4pmol/g BW was attenuated by treatment with the orexin receptor 1 antagonist, SB334867, at 10pmol/g BW. Since intact goldfish prefer a black to a white background area, or the lower to the upper area of a tank, we used two types of preference tests (black/white and upper/lower tests) for measuring anxiety-like behavior in goldfish. Intracerebroventricular administration of orexin A at 4pmol/g BW shortened the time spent in the white background area, and increased the time taken to move from the lower to the upper area. This action of orexin A mimicked that of the central-type benzodiazepine receptor inverse agonist, FG-7142 (an anxiogenic agent), at 4pmol/g BW. The anxiogenic-like effect of orexin A was abolished by treatment with SB334867 at 10pmol/g BW. These results indicate that orexin A potently affects psychomotor activity in goldfish.
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Affiliation(s)
- Tomoya Nakamachi
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama 930-8555, Japan
| | - Haruki Shibata
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama 930-8555, Japan
| | - Atsushi Sakashita
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama 930-8555, Japan
| | - Naoto Iinuma
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama 930-8555, Japan
| | - Kohei Wada
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama 930-8555, Japan
| | - Norifumi Konno
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama 930-8555, Japan
| | - Kouhei Matsuda
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama 930-8555, Japan; Laboratory of Regulatory Biology, Graduate School of Innovative Life Science, University of Toyama, 3190-Gofuku, Toyama 930-8555, Japan.
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30
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Amano M, Mizusawa N, Okubo K, Amiya N, Mizusawa K, Chiba H, Yamamoto N, Takahashi A. Cloning of corticotropin-releasing hormone (CRH) precursor cDNA and immunohistochemical detection of CRH peptide in the brain of the Japanese eel, paying special attention to gonadotropin-releasing hormone. Cell Tissue Res 2014; 356:243-51. [PMID: 24477796 DOI: 10.1007/s00441-013-1784-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 11/26/2013] [Indexed: 11/29/2022]
Abstract
The stress-related corticotropin-releasing hormone (CRH) was first identified by isolation of its cDNA from the brain of the Japanese eel Anguilla japonica. CRH cDNA encodes a signal peptide, a cryptic peptide and CRH (41 amino acids). The sequence homology to mammalian CRH is high. Next, the distribution of CRH-immunoreactive (ir) cell bodies and fibers in the brain and pituitary were examined by immunohistochemistry. CRH-ir cell bodies were detected in several brain regions, e.g., nucleus preopticus pars magnocellularis, nucleus preopticus pars gigantocellularis and formatio reticularis superius. In the brain, CRH-ir fibers were distributed not only in the hypothalamus but also in various regions. Some CRH-ir fibers projected to adrenocorticotropic hormone (ACTH) cells in the rostral pars distalis of the pituitary and also the α-melanocyte-stimulating hormone (α-MSH) cells in the pars intermedia of the pituitary. Finally, the neuroanatomical relationship between the CRH neurons and gonadotropin-releasing hormone (GnRH) neurons was examined by dual-label immunohistochemistry. CRH-ir fibers were found to be in close contact with GnRH-ir cell bodies in the hypothalamus and in the midbrain tegmentum and GnRH-ir fibers were in close contact with CRH-ir cell bodies in the nucleus preopticus pars magnocellularis. These results suggest that CRH has some physiological functions other than the stimulation of ACTH and α-MSH secretion and that reciprocal connections may exist between the CRH neurons and GnRH neurons in the brain of the Japanese eel.
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Affiliation(s)
- Masafumi Amano
- School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa, 252-0373, Japan,
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31
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Shahjahan M, Kitahashi T, Parhar IS. Central pathways integrating metabolism and reproduction in teleosts. Front Endocrinol (Lausanne) 2014; 5:36. [PMID: 24723910 PMCID: PMC3971181 DOI: 10.3389/fendo.2014.00036] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 03/11/2014] [Indexed: 01/08/2023] Open
Abstract
Energy balance plays an important role in the control of reproduction. However, the cellular and molecular mechanisms connecting the two systems are not well understood especially in teleosts. The hypothalamus plays a crucial role in the regulation of both energy balance and reproduction, and contains a number of neuropeptides, including gonadotropin-releasing hormone (GnRH), orexin, neuropeptide-Y, ghrelin, pituitary adenylate cyclase-activating polypeptide, α-melanocyte stimulating hormone, melanin-concentrating hormone, cholecystokinin, 26RFamide, nesfatin, kisspeptin, and gonadotropin-inhibitory hormone. These neuropeptides are involved in the control of energy balance and reproduction either directly or indirectly. On the other hand, synthesis and release of these hypothalamic neuropeptides are regulated by metabolic signals from the gut and the adipose tissue. Furthermore, neurons producing these neuropeptides interact with each other, providing neuronal basis of the link between energy balance and reproduction. This review summarizes the advances made in our understanding of the physiological roles of the hypothalamic neuropeptides in energy balance and reproduction in teleosts, and discusses how they interact with GnRH, kisspeptin, and pituitary gonadotropins to control reproduction in teleosts.
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Affiliation(s)
- Md. Shahjahan
- Brain Research Institute, School of Medicine and Health Sciences, Monash University Malaysia, Petaling Jaya, Malaysia
| | - Takashi Kitahashi
- Brain Research Institute, School of Medicine and Health Sciences, Monash University Malaysia, Petaling Jaya, Malaysia
| | - Ishwar S. Parhar
- Brain Research Institute, School of Medicine and Health Sciences, Monash University Malaysia, Petaling Jaya, Malaysia
- *Correspondence: Ishwar S. Parhar, Brain Research Institute, School of Medicine and Health Sciences, Monash University Malaysia, Petaling Jaya 46150, Malaysia e-mail:
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32
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Shimizu S, Kaiya H, Matsuda K. Stimulatory effect of ghrelin on food intake in bullfrog larvae. Peptides 2014; 51:74-9. [PMID: 24211488 DOI: 10.1016/j.peptides.2013.10.028] [Citation(s) in RCA: 17] [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: 10/17/2013] [Revised: 10/30/2013] [Accepted: 10/30/2013] [Indexed: 12/29/2022]
Abstract
Ghrelin is a potent orexigenic peptide implicated in appetite regulation in rodents. However, except for teleost fish, the involvement of ghrelin in the regulation of feeding in non-mammalian vertebrates has not been well studied. Anuran amphibian larvae feed and grow during the pre- and prometamorphic stages, but, thereafter they stop feeding as the metamorphic climax approaches. Therefore, orexigenic factors seem to play important roles in growing larvae. In the present study, we examined the effect of intraperitoneal (IP) or intracerebroventricular (ICV) administration of synthetic bullfrog ghrelin (n-octanoylated 28-amino acid form) on food intake in larvae at the prometamorphic stages. Cumulative food intake was significantly increased by IP (8 and 16pmol/g body weight (BW)) or ICV (0.5 and 1pmol/g BW) administration of ghrelin during a 15-min observation period. The orexigenic action of ghrelin at 8pmol/g BW (IP) or at 0.5pmol/g BW (ICV) was blocked by treatment with a growth hormone secretagogue-receptor antagonist, [D-Lys(3)]GHRP-6 at 80pmol/g BW (IP) or at 5pmol/g BW (ICV). We then investigated the effect of feeding status on expression levels of the ghrelin transcript in the hypothalamus and gastrointestinal tract. Ghrelin mRNA levels in both were decreased 15 and 60min after feeding. These results indicate that ghrelin acts as an orexigenic factor in bullfrog larvae.
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Affiliation(s)
- Shunsuke Shimizu
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan
| | - Hiroyuki Kaiya
- Department of Biochemistry, National Cerebral and Cardiovascular Center (NCVC) Research Institute, Suita, Osaka 565-8565, Japan
| | - Kouhei Matsuda
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan; Laboratory of Regulatory Biology, Graduate School of Innovative Life Science, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan.
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Ortega VA, Lovejoy DA, Bernier NJ. Appetite-suppressing effects and interactions of centrally administered corticotropin-releasing factor, urotensin I and serotonin in rainbow trout (Oncorhynchus mykiss). Front Neurosci 2013; 7:196. [PMID: 24194695 PMCID: PMC3810612 DOI: 10.3389/fnins.2013.00196] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 10/08/2013] [Indexed: 01/03/2023] Open
Abstract
Corticotropin-releasing factor (CRF), urotensin I (UI) and serotonin (5-HT) are generally recognized as key regulators of the anorexigenic stress response in vertebrates, yet the proximal effects and potential interactions of these central messengers on food intake in salmonids are not known. Moreover, no study to date in fishes has compared the appetite-suppressing effects of CRF and UI using species-specific peptides. Therefore, the objectives of this study were to (1) assess the individual effects of synthesized rainbow trout CRF (rtCRF), rtUI as well as 5-HT on food intake in rainbow trout, and (2) determine whether the CRF and serotonergic systems interact in the regulation of food intake in this species. Intracerebroventricular (icv) injections of rtCRF and rtUI both suppressed food intake in a dose-related manner but rtUI [ED50 = 17.4 ng/g body weight (BW)] was significantly more potent than rtCRF (ED50 = 105.9 ng/g BW). Co-injection of either rtCRF or rtUI with the CRF receptor antagonist α-hCRF(9–41) blocked the reduction in food intake induced by CRF-related peptides. Icv injections of 5-HT also inhibited feeding in a dose-related manner (ED50 = 14.7 ng/g BW) and these effects were blocked by the serotonergic receptor antagonist methysergide. While the anorexigenic effects of 5-HT were reversed by α-hCRF(9–41) co-injection, the appetite-suppressing effects of either rtCRF or rtUI were not affected by methysergide co-injection. These results identify CRF, UI and 5-HT as anorexigenic agents in rainbow trout, and suggest that 5-HT-induced anorexia may be at least partially mediated by CRF- and/or UI-secreting neurons.
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Affiliation(s)
- Van A Ortega
- Department of Integrative Biology, University of Guelph Guelph, ON, Canada
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34
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Tang Z, Sun C, Yan A, Wu S, Qin C, Zhang Y, Li W. Genes involved in fatty acid metabolism: molecular characterization and hypothalamic mRNA response to energy status and neuropeptide Y treatment in the orange-spotted grouper Epinephelus coioides. Mol Cell Endocrinol 2013; 376:114-24. [PMID: 23806557 DOI: 10.1016/j.mce.2013.06.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 06/12/2013] [Accepted: 06/15/2013] [Indexed: 12/19/2022]
Abstract
As in mammals, fatty acid (FA) metabolism plays diverse and vital roles in regulating food intake in fish. Multiple lines of evidence suggest that the effect of FA metabolism on food intake is linked to changes in the level of neuropeptide Y (NPY) in the hypothalamus of the rainbow trout. In mammals, the evidence suggests that FA metabolism regulates feeding via hypothalamic NPY. NPY is therefore considered an important factor that mediates the modulation of food intake by FA metabolism in vertebrates. The stimulatory effect of NPY on food intake is well known. However, to the best of our knowledge, the effect of NPY on FA metabolism in the hypothalamus has not been examined. In this study, we cloned the cDNA of four key enzymes involved in FA metabolism and assessed the effect of energy status and NPY on their mRNA expression in the hypothalamus of grouper. The full-length cDNAs of UCP2 and CPT1a and the partial coding sequence (CDS) of ACC1 and FAS were isolated from the grouper hypothalamus. These genes are expressed in the hypothalamus and during the organogenetic stage of embryogenesis. A feeding rhythm study showed that the hypothalamic expression level of NPY and CPT1a was highly correlated with feeding rhythm. Long-term fasting was found to significantly induce the hypothalamic mRNA expression of NPY, CPT1a and UCP2. An in vitro study demonstrated that NPY strongly stimulated CPT1a and UCP2 mRNA expression in a time- and dose-dependent manner. Collectively, these results suggest that these four genes related to FA metabolism may play a role in regulating food intake in grouper and, that NPY modulates FA metabolism in the grouper hypothalamus. This study showed, for the first time in vertebrates, the effect of NPY on the gene expression of FA metabolism-related enzymes.
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Affiliation(s)
- Zhiguo Tang
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China
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Shimizu S, Azuma M, Morimoto N, Kikuyama S, Matsuda K. Effect of neuropeptide Y on food intake in bullfrog larvae. Peptides 2013; 46:102-7. [PMID: 23756158 DOI: 10.1016/j.peptides.2013.05.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 05/30/2013] [Accepted: 05/30/2013] [Indexed: 10/26/2022]
Abstract
Neuropeptide Y (NPY) is a potent orexigenic neuropeptide implicated in appetite regulation in mammals. However, except for teleost fish such as the goldfish and zebrafish, the involvement of NPY in the regulation of feeding in non-mammalian vertebrates has not been well studied. Anuran amphibian larvae feed and grow during the pre- and pro-metamorphic stages, but, thereafter they stop feeding as the metamorphic climax approaches. Therefore, orexigenic factors seem to play important roles in pre- and pro-metamorphic larvae. We investigated the role of NPY in food intake using bullfrog larvae including pre- and pro-metamorphic stages, and examined the effect of feeding status on the expression level of the NPY transcript in the hypothalamus. NPY mRNA levels in hypothalamus specimens obtained from larvae that had been fasted for 3 days were higher than those in larvae that had been fed normally. We then investigated the effect of intracerebroventricular (ICV) administration of NPY on food intake in the larvae. Cumulative food intake was significantly increased by ICV administration of NPY (5 and 10 pmol/g body weight, BW) during a 15-min observation period. The NPY-induced orexigenic action (10 pmol/g BW) was blocked by treatment with a NPY Y1 receptor antagonist, BIBP-3226 (100 pmol/g BW). These results indicate that NPY acts as an orexigenic factor in bullfrog larvae.
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Affiliation(s)
- Shunsuke Shimizu
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan
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Matsuda K, Hagiwara Y, Shibata H, Sakashita A, Wada K. Ovine corticotropin-releasing hormone (oCRH) exerts an anxiogenic-like action in the goldfish, Carassius auratus. Gen Comp Endocrinol 2013; 188:118-22. [PMID: 23321398 DOI: 10.1016/j.ygcen.2013.01.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 12/25/2012] [Accepted: 01/03/2013] [Indexed: 01/30/2023]
Abstract
Corticotropin-releasing hormone (CRH) is a member of the hypothalamic neuropeptide family that includes urocortins, urotensin I and sauvagine in vertebrates. CRH and urocortin act as anorexigenic factors for satiety regulation in rodents. In a goldfish model, intracerebroventricular (ICV) administration of ovine CRH (oCRH) affects not only food intake, but also locomotor activity. However, there is no information regarding the psychophysiological roles of CRH in goldfish. Therefore, we investigated the effect of oCRH on psychomotor activity in this species. ICV administration of synthetic oCRH at 20 pmol/g body weight (BW) enhanced locomotor activity. Since intact goldfish prefer the lower to the upper area of a tank, we developed a method for measuring the time taken for fish to move from the lower to the upper area. ICV administration of oCRH at 20 pmol/g BW and the central-type benzodiazepine receptor inverse agonist FG-7142 (an anxiogenic agent) at 1-4 pmol/g BW both increased the time taken to move from the lower to the upper area. This anxiogenic-like effect of oCRH was abolished by the CRH receptor antagonist α-helical CRH(9-41) (100 pmol/g BW). These results indicate that CRH can potently affect locomotor and psychomotor activities in goldfish.
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Affiliation(s)
- Kouhei Matsuda
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, Toyama 930-8555, Japan.
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Matsuda K. Regulation of feeding behavior and psychomotor activity by corticotropin-releasing hormone (CRH) in fish. Front Neurosci 2013; 7:91. [PMID: 23754974 PMCID: PMC3667241 DOI: 10.3389/fnins.2013.00091] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 05/14/2013] [Indexed: 11/21/2022] Open
Abstract
Corticotropin-releasing hormone (CRH) is a hypothalamic neuropeptide belonging to a family of neuropeptides that includes urocortins, urotensin I, and sauvagine in vertebrates. CRH and urocortin act as anorexigenic factors for satiety regulation in fish. In a goldfish model, intracerebroventricular (ICV) administration of CRH has been shown to affect not only food intake, but also locomotor and psychomotor activities. In particular, CRH elicits anxiety-like behavior as an anxiogenic neuropeptide in goldfish, as is the case in rodents. This paper reviews current knowledge of CRH and its related peptides derived from studies of teleost fish, as representative non-mammals, focusing particularly on the role of the CRH system, and examines its significance from a comparative viewpoint.
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Affiliation(s)
- Kouhei Matsuda
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, Graduate School of Innovative Life Science, University of Toyama Toyama, Japan
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Upton KR, Riley LG. Acute stress inhibits food intake and alters ghrelin signaling in the brain of tilapia (Oreochromis mossambicus). Domest Anim Endocrinol 2013; 44:157-64. [PMID: 23291012 DOI: 10.1016/j.domaniend.2012.10.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 10/04/2012] [Accepted: 10/05/2012] [Indexed: 10/27/2022]
Abstract
This study investigated the effect of an acute stress on food intake and on the expression of neuropeptide Y (NPY), corticotropin-releasing hormone (CRH), and ghrelin and its receptors, growth hormone secretagogue receptors (GHSRs) in the tilapia (Oreochromis mossambicus). Food intake was significantly (P < 0.01) reduced in fish after a 30-min crowding and handling stress. In a second group of animals exposed to the same 30-min stressor, tissue samples were collected immediately after the stressor to determine changes in the neuroendocrine regulators of food intake. Although CRH and NPY are considered the major mediators of appetite during stress, both mRNA levels were unaltered in the telencephalon/pre-optic area and in the hypothalamic/optic tectum. Interestingly, there was an elevation in the ghrelin transcript (P < 0.05) in the telencephalon/pre-optic area and elevation of its functional receptor (GHSR1a-LR) (P < 0.001) in the hypothalamic/optic tectum. Elevation of GHSR-LR heteronuclear RNA (P < 0.01) in the telencephalon/pre-optic area and suppression in the hypothalamic/optic tectum (P < 0.001) suggest rapid control of the ghrelin regulatory system in response to acute stress. These results suggest that ghrelin signaling is altered during acute stress. It is not clear if these changes result in altered feeding behavior because no changes in CRH or NPY mRNA expression were observed or if ghrelin is playing a role in regulating overall metabolic changes after acute stress.
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Affiliation(s)
- K R Upton
- Department of Biology, California State University at Fresno, Fresno, CA 93740, USA
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39
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Neuroendocrine control of feeding behavior and psychomotor activity by pituitary adenylate cyclase-activating polypeptide (PACAP) in vertebrates. Obes Res Clin Pract 2013; 7:e1-7. [DOI: 10.1016/j.orcp.2012.10.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 10/16/2012] [Accepted: 10/22/2012] [Indexed: 11/23/2022]
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Tao YX, Yuan ZH, Xie J. G Protein-Coupled Receptors as Regulators of Energy Homeostasis. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 114:1-43. [DOI: 10.1016/b978-0-12-386933-3.00001-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Matsuda K, Sakashita A, Yokobori E, Azuma M. Neuroendocrine control of feeding behavior and psychomotor activity by neuropeptideY in fish. Neuropeptides 2012; 46:275-83. [PMID: 23122775 DOI: 10.1016/j.npep.2012.09.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 07/12/2012] [Accepted: 09/18/2012] [Indexed: 10/27/2022]
Abstract
Neuropeptide Y (NPY) is a neuropeptide distributed widely among vertebrates. In mammals, NPY and its related peptides such as pancreatic polypeptide and peptide YY (PYY) are distributed throughout the brain and gastrointestinal tissues, and are centrally involved in many physiological functions such as the regulation of food intake, locomotion and psychomotor activities through their receptors. With regard to non-mammalian vertebrates, there has also been intensive study aimed at the identification and functional characterization of NPY, PYY and their receptors, and recent investigations of the role of NPY have revealed that it exerts several behavioral effects in goldfish and zebrafish. Both of these species are excellent teleost fish models, in which it has been demonstrated that NPY increases food consumption as an orexigenic factor and reduces locomotor activity, as is the case in mammals. This paper reviews current knowledge of NPY derived from studies of teleost fish, as representative non-mammals, focusing particularly on the role of the NPY system, and examines its significance from a comparative viewpoint.
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Affiliation(s)
- Kouhei Matsuda
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan.
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42
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Janzen WJ, Duncan CA, Riley LG. Cortisol treatment reduces ghrelin signaling and food intake in tilapia, Oreochromis mossambicus. Domest Anim Endocrinol 2012; 43:251-9. [PMID: 22657576 DOI: 10.1016/j.domaniend.2012.04.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 04/03/2012] [Accepted: 04/13/2012] [Indexed: 10/28/2022]
Abstract
It is well known that after a stressor, levels of plasma cortisol rise, inducing physiological changes within the animal that are directed toward maintaining homeostasis. Less well understood is the role of cortisol in regulating food intake in teleosts. This study investigated the effect of cortisol on food intake and regulation of the neuroendocrine appetite-stimulating hormones, neuropeptide Y (NPY) and ghrelin, in tilapia (Oreochromis mossambicus). Male and female tilapia were randomly assigned to one of the following treatments: unhandled control, vehicle-injected control, or cortisol (2 μg/g BW). Food intake was determined 24 h after injection during a 1-h feeding trial. Cortisol reduced food intake (P<0.001). An identical study was conducted to measure the effects of 24-h cortisol treatment on the endocrine regulators of food intake. Cortisol reduced stomach expression of ghrelin mRNA (P<0.05) and plasma concentrations of ghrelin (P<0.05). In the hypothalamus/optic tectum cortisol reduced levels of GHSR1a-LR (biologically active ghrelin receptor) mRNA. In the telencephalon/preoptic area cortisol significantly reduced levels of NPY and GHSR1b-LR (biologically inactive ghrelin receptor) mRNA. These findings suggest that anorexigenic actions of cortisol may be mediated via two separate pathways: (1) reducing circulating ghrelin levels as well as GHSR1a-LR expression in the hypothalamus/optic tectum and/or (2) suppressing NPY expression in the telencephalon/preoptic area.
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Affiliation(s)
- W J Janzen
- Department of Biology, California State University at Fresno, Fresno, CA 93740, USA
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Yokobori E, Azuma M, Nishiguchi R, Kang KS, Kamijo M, Uchiyama M, Matsuda K. Neuropeptide Y stimulates food intake in the Zebrafish, Danio rerio. J Neuroendocrinol 2012; 24:766-73. [PMID: 22250860 DOI: 10.1111/j.1365-2826.2012.02281.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Neuropeptide Y (NPY) is a potent orexigenic neuropeptide implicated in feeding regulation in mammals. However, except for the case of the goldfish, the involvement of NPY in the feeding behaviour of teleost fish has not well been studied. Therefore, we investigated the role of NPY in food intake using a zebrafish (Danio rerio) model because the molecular bases of NPY and its receptor have been well studied in this species. We examined the effect of feeding status on NPY-like immunoreactivity and the expression level of the NPY transcript in the brain. The number of neuronal cells showing NPY-like immunoreactivity in the hypothalamic regions, including the periventricular nucleus of posterior tuberculum and the posterior tuberal nucleus, was significantly increased in fish fasted for 7 days. NPY mRNA levels in the hypothalamus, but not the telencephalon, obtained from fish fasted for 7 days were higher than those in fish that had been fed normally. We then investigated the effect of i.c.v. administration of NPY on food intake. Cumulative food intake was significantly increased by i.c.v. administration of NPY (at 1 and 10 pmol/g body weight; BW) during a 60-min observation period. The NPY-induced orexigenic action (at 10 pmol/g BW) was blocked by treatment with a NPY Y1 receptor antagonist, BIBP-3226, at 100 pmol/g BW. These results indicate that NPY acts as an orexigenic factor in the zebrafish.
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Affiliation(s)
- E Yokobori
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, Toyama, Japan
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Yahashi S, Kang KS, Kaiya H, Matsuda K. GHRP-6 mimics ghrelin-induced stimulation of food intake and suppression of locomotor activity in goldfish. Peptides 2012; 34:324-8. [PMID: 22349352 DOI: 10.1016/j.peptides.2012.01.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Revised: 01/31/2012] [Accepted: 01/31/2012] [Indexed: 11/20/2022]
Abstract
Ghrelin was first identified and characterized from rat stomach as an endogenous ligand for the growth hormone secretagogue (GHS) receptor (GHS-R). Ghrelin also acts as an orexigenic factor and regulates energy balance in rodents. In goldfish, native ghrelin consists of 11 molecular variants, the major form being a 17-residue peptide with n-octanoic acid modification (n-octanoyl ghrelin17), and intraperitoneal (IP) administration of n-octanoyl ghrelin17 induces central actions such as stimulation of food intake and suppression of locomotor activity through capsaicin-sensitive afferents. Four types of GHS-Rs (1a-1, 1a-2, 2a-1 and 2a-2) have been identified in goldfish, and one GHS, GHRP-6, can activate only GHS-R2a-1 in vitro. However, there is no information about the effect of GHRP-6 on food intake and locomotor activity in goldfish in vivo. Therefore, in the present study, we examined whether IP-administered GHRP-6 would mimic the orexigenic action of n-octanoyl ghrelin17 and its suppression of locomotor activity. IP administration of GHRP-6 at 1pmol/g body weight (BW) stimulated food intake, and was equipotent to the orexigenic action of n-octanoyl ghrelin17 at 10 pmol/g BW. IP-injected GHRP-6 at 1 pmol/g BW also induced a significant decrease of locomotor activity, as was the case for IP-injected n-octanoyl ghrelin17 at 10 pmol/g BW. The action of GHRP-6 was blocked by IP-preinjected capsaicin at 160 nmol/g BW. These results suggest that the central action of GHRP-6 might be mediated via the GHS-R2a-1-signaling pathway, and subsequently through capsaicin-sensitive afferents in goldfish.
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Affiliation(s)
- Satowa Yahashi
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama 930-8555, Japan
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45
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Kamijo M, Kojima K, Maruyama K, Konno N, Motohashi E, Ikegami T, Uchiyama M, Shioda S, Ando H, Matsuda K. Neuropeptide Y in tiger puffer (Takifugu rubripes): distribution, cloning, characterization, and mRNA expression responses to prandial condition. Zoolog Sci 2012; 28:882-90. [PMID: 22132785 DOI: 10.2108/zsj.28.882] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Neuropeptide tyrosine (NPY) is a potent orexigenic neuropeptide implicated in feeding regulation in rodents. However, the involvement of NPY in feeding behavior has not well been studied in fish. Therefore, we investigated the role of NPY in food intake using a tiger puffer (Takifugu rubripes) model. We observed the distribution of NPY-like immunoreactivity in the brain. Neuronal cell bodies containing NPY were located in the telencephalon, hypothalamus, mesencephalon, and medulla oblongata, and their nerve fibers were also found throughout the brain. We cloned two cDNAs, encoding NPYa and NPYb orthologs, respectively, from the brain, and also confirmed two genes encoding these NPYs in the Takifugu genome database. We examined the distribution of these transcripts in the brain using real-time PCR. Levels of NPYa mRNA in the telencephalon, mesencephalon and hypothalamus were much higher than in the medulla oblongata and cerebellum, whereas levels of NPYb mRNA in the medulla oblongata were higher than in other regions. We also examined prandial effects on the expression level of these transcripts in the telencephalon and hypothalamus. NPYa mRNA levels in the hypothalamus, but not in the telencephalon, obtained from fish fasted for one week were higher than those in fish that had been fed normally. The level was decreased at 2 h after feeding. Levels of NPYb mRNA were not affected by prandial conditions. These results suggest that NPY is present throughout the brain, and that NPYa, but not NPYb, in the hypothalamus is involved in the feeding regulation in the tiger puffer.
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Affiliation(s)
- Motoki Kamijo
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, Toyama 930-8555, Japan
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Feeding behaviors and ORXR–β-GABAAR subunit interactions in Carassius auratus. Neurotoxicol Teratol 2011; 33:641-50. [DOI: 10.1016/j.ntt.2011.09.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 09/28/2011] [Accepted: 09/29/2011] [Indexed: 01/30/2023]
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Kang KS, Yahashi S, Matsuda K. Central and peripheral effects of ghrelin on energy balance, food intake and lipid metabolism in teleost fish. Peptides 2011; 32:2242-7. [PMID: 21601604 DOI: 10.1016/j.peptides.2011.05.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 04/24/2011] [Accepted: 05/05/2011] [Indexed: 11/23/2022]
Abstract
Ghrelin was first identified and characterized from rat stomach as an endogenous ligand for the growth hormone secretagogue receptor. Ghrelin and its receptor system are present not only in peripheral tissues such as stomach and intestine, but also in the central nervous system of mammals. Interestingly, administration of ghrelin induces an orexigenic effect and also modifies locomotor activity, suggesting its involvement in feeding control and the regulation of energy balance, in addition to the regulation of growth hormone release. Information about ghrelin in non-mammals, such as teleost fish, has also been increasing, and important data have been obtained. An understanding of the evolutionary background of the energy regulation system and the central and peripheral roles of ghrelin in teleost fish could provide indications as to their roles in mammals, particularly humans. In this review, we overview the central and peripheral effects of ghrelin on energy balance, locomotor activity, and lipid metabolism in teleost fish.
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Affiliation(s)
- Ki Sung Kang
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama 930-8555, Japan
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Kang KS, Yahashi S, Azuma M, Sakashita A, Shioda S, Matsuda K. Effect of intraperitoneal injection of curcumin on food intake in a goldfish model. J Mol Neurosci 2011; 45:172-6. [PMID: 20514526 DOI: 10.1007/s12031-010-9390-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Accepted: 05/06/2010] [Indexed: 01/30/2023]
Abstract
Although spice compounds have several pharmacological and biochemical actions such as antioxidant activity, their physiological effects on neuropeptides related to feeding regulation are not well known. The aim of the present study was to identify the pharmacological activities of spice compounds on appetite regulation using a goldfish (Carassius auratus) model with emphasis on the role of neuropeptides. The spice compounds used in this study were curcumin, piperine, and ursolic acid. Goldfish were injected intraperitoneally with test solutions containing each spice or vehicle (including 10% dimethyl sulfoxide in saline), and the changes in food intake were measured every 15 min for 60 min. Among the tested spice compounds, curcumin was found to reduce cumulative food intake and was thus selected for further experiments. Pretreatment with capsaicin, a neurotoxin of afferent nerves, abolished the curcumin-induced decrease of food intake. Curcumin-induced anorexigenic action was also attenuated by intracerebroventricular injection of the corticotropin-releasing hormone (CRH) receptor antagonist α-helical CRH((9-41)). We also examined the expression levels of mRNA for CRH, which is a potent anorexigenic neuropeptide in goldfish, in the diencephalon at 1 h after treatment with curcumin, and found that they were increased. Therefore, the reduction of appetite induced by curcumin treatment in goldfish was suggested to be mediated by the vagal afferent and subsequently through the CRH/CRH receptor pathway.
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Affiliation(s)
- Ki Sung Kang
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama, Toyama 930-8555, Japan
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50
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Kato T, Yamada Y, Yamamoto N. General visceral and gustatory connections of the posterior thalamic nucleus of goldfish. J Comp Neurol 2011; 519:3102-23. [DOI: 10.1002/cne.22669] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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