PMC:5126056 / 40864-49623 JSONTXT

{"project":"0_colil","denotations":[{"id":"27965528-16762453-246691","span":{"begin":303,"end":307},"obj":"16762453"},{"id":"27965528-16840648-246688","span":{"begin":162,"end":166},"obj":"16840648"},{"id":"27965528-24468550-246689","span":{"begin":185,"end":189},"obj":"24468550"},{"id":"27965528-23229307-246690","span":{"begin":229,"end":233},"obj":"23229307"},{"id":"27965528-11134597-246692","span":{"begin":396,"end":400},"obj":"11134597"},{"id":"27965528-21643748-246695","span":{"begin":517,"end":521},"obj":"21643748"},{"id":"27965528-24374761-246696","span":{"begin":558,"end":562},"obj":"24374761"},{"id":"27965528-27717774-246698","span":{"begin":769,"end":773},"obj":"27717774"},{"id":"27965528-27468955-246699","span":{"begin":817,"end":821},"obj":"27468955"},{"id":"27965528-22484564-246701","span":{"begin":977,"end":981},"obj":"22484564"},{"id":"27965528-26421838-246702","span":{"begin":1016,"end":1020},"obj":"26421838"},{"id":"27965528-18644459-246703","span":{"begin":1133,"end":1137},"obj":"18644459"},{"id":"27965528-17254820-246704","span":{"begin":1184,"end":1188},"obj":"17254820"},{"id":"27965528-25624165-246706","span":{"begin":1351,"end":1355},"obj":"25624165"},{"id":"27965528-16488069-246707","span":{"begin":1459,"end":1463},"obj":"16488069"},{"id":"27965528-21078323-246709","span":{"begin":1785,"end":1789},"obj":"21078323"},{"id":"27965528-26320854-246710","span":{"begin":1956,"end":1960},"obj":"26320854"},{"id":"27965528-11134597-246712","span":{"begin":2188,"end":2192},"obj":"11134597"},{"id":"27965528-24573274-246713","span":{"begin":2275,"end":2279},"obj":"24573274"},{"id":"27965528-22700585-246715","span":{"begin":2495,"end":2499},"obj":"22700585"},{"id":"27965528-27156808-246716","span":{"begin":2517,"end":2521},"obj":"27156808"},{"id":"27965528-21643748-246717","span":{"begin":2551,"end":2555},"obj":"21643748"},{"id":"27965528-27717774-246718","span":{"begin":2639,"end":2643},"obj":"27717774"},{"id":"27965528-22484564-246720","span":{"begin":2772,"end":2776},"obj":"22484564"},{"id":"27965528-17254820-246721","span":{"begin":2812,"end":2816},"obj":"17254820"},{"id":"27965528-21078323-246722","span":{"begin":2909,"end":2913},"obj":"21078323"},{"id":"27965528-18644459-246723","span":{"begin":2968,"end":2972},"obj":"18644459"},{"id":"27965528-21452197-246724","span":{"begin":3037,"end":3041},"obj":"21452197"},{"id":"27965528-26320854-246725","span":{"begin":3230,"end":3234},"obj":"26320854"},{"id":"27965528-27717774-246726","span":{"begin":3259,"end":3263},"obj":"27717774"},{"id":"27965528-27468955-246727","span":{"begin":3291,"end":3295},"obj":"27468955"},{"id":"27965528-22366470-246728","span":{"begin":3332,"end":3336},"obj":"22366470"},{"id":"27965528-17254820-246729","span":{"begin":3373,"end":3377},"obj":"17254820"},{"id":"27965528-26421838-246730","span":{"begin":3504,"end":3508},"obj":"26421838"},{"id":"27965528-27468955-246731","span":{"begin":3589,"end":3593},"obj":"27468955"},{"id":"27965528-25624165-246733","span":{"begin":3685,"end":3689},"obj":"25624165"},{"id":"27965528-25151310-246735","span":{"begin":4197,"end":4201},"obj":"25151310"},{"id":"27965528-27717774-246736","span":{"begin":4301,"end":4305},"obj":"27717774"},{"id":"27965528-17043670-246737","span":{"begin":4993,"end":4997},"obj":"17043670"},{"id":"27965528-17043670-246738","span":{"begin":5494,"end":5498},"obj":"17043670"},{"id":"27965528-17077189-246739","span":{"begin":5506,"end":5510},"obj":"17077189"},{"id":"27965528-25560696-246740","span":{"begin":5518,"end":5522},"obj":"25560696"},{"id":"27965528-21208603-246741","span":{"begin":5637,"end":5641},"obj":"21208603"},{"id":"27965528-6364981-246742","span":{"begin":5703,"end":5707},"obj":"6364981"},{"id":"27965528-9806347-246743","span":{"begin":5766,"end":5770},"obj":"9806347"},{"id":"27965528-21208603-246744","span":{"begin":6033,"end":6037},"obj":"21208603"},{"id":"27965528-12972325-246745","span":{"begin":6234,"end":6238},"obj":"12972325"},{"id":"27965528-12972325-246746","span":{"begin":6359,"end":6363},"obj":"12972325"},{"id":"27965528-12972325-246747","span":{"begin":6492,"end":6496},"obj":"12972325"},{"id":"27965528-20005228-246748","span":{"begin":6628,"end":6632},"obj":"20005228"},{"id":"27965528-14709799-246749","span":{"begin":6997,"end":7001},"obj":"14709799"},{"id":"27965528-27644743-246750","span":{"begin":7104,"end":7108},"obj":"27644743"},{"id":"27965528-25990920-246751","span":{"begin":7227,"end":7231},"obj":"25990920"},{"id":"27965528-27149948-246752","span":{"begin":7464,"end":7468},"obj":"27149948"},{"id":"27965528-16461561-246753","span":{"begin":7606,"end":7610},"obj":"16461561"},{"id":"27965528-21377470-246754","span":{"begin":7713,"end":7717},"obj":"21377470"},{"id":"27965528-27149948-246755","span":{"begin":7819,"end":7823},"obj":"27149948"},{"id":"27965528-26123591-246756","span":{"begin":7937,"end":7941},"obj":"26123591"},{"id":"27965528-15804516-246757","span":{"begin":8119,"end":8123},"obj":"15804516"},{"id":"27965528-25624165-246758","span":{"begin":8465,"end":8469},"obj":"25624165"}],"text":"Anorexigenic factors\n\nCART\nCART is a peptide which transcript expression is regulated by administration of cocaine or amphetamine in rodents (Vicentic and Jones, 2007; Subhedar et al., 2014) and amphetamine in goldfish (Volkoff, 2013). CART acts as an anorexigenic factor in mammals (Larsen and Hunter, 2006), and was first identified and shown to be anorexigenic in goldfish (Volkoff and Peter, 2000, 2001a).\nTwo CART isoforms have been identified in goldfish (Volkoff and Peter, 2001a) and common carp (Wan et al., 2012), and 4 in zebrafish (Akash et al., 2014) whereas, to date, only one form has been isolated for grass carp (Zhou et al., 2013; Liu et al., 2014), Characiformes [pirapitinga (serrasalmidae) (Volkoff, 2015a), pacu (serrasasalmidae) (Volkoff et al., 2017) and dourado (characidae) (Volkoff et al., 2016), red bellied piranha (serrasalmidae) (Volkoff, 2014a)], Salmoniformes [Atlantic salmon (Murashita et al., 2009a), rainbow trout (Figueiredo-Silva et al., 2012), Arctic charr (Striberny et al., 2015) and lake trout (Salvelinus namaycush) (Volkoff et al., 2007)], Siluriformes (channel catfish Kobayashi et al., 2008), Gadiformes (Atlantic cod Kehoe and Volkoff, 2007), Perciformes (cunner Babichuk and Volkoff, 2013), winter flounder (MacDonald and Volkoff, 2009a) and Atlantic halibut (Hippoglossus hippoglossus) (Gomes et al., 2015) (Pleuronectiformes), venomous toadfish Thalassophryne nattereri (Batrachoidiforme) (Magalhaes et al., 2006), rainbow smelt (Osmerus mordax) (Osmeriforme), pufferfishes (Takifugu rubripes and Tetraodon nigroviridis, Tetraodontiforme) and stickleback Gasterosteus aculeatus (Gasterosteiforme) (cited in Murashita et al., 2009a). However, six forms of CART have been identified in the medaka (Beloniforme) (Murashita and Kurokawa, 2011) and seven forms in Senegalese sole Solea senegalensis (Pleuronectiforme), the highest number of CART genes reported to date in a vertebrate species (Bonacic et al., 2015). The only elasmobranch CART identified to date is that of winter skate (Rajiforme) (MacDonald and Volkoff, 2009b).\nCART injections induce a decrease in food intake and an increase in locomotion in goldfish (Volkoff and Peter, 2000) and enhance responsiveness to sensory stimuli in zebrafish larvae (Woods et al., 2014), suggesting that CART is involved in feeding/searching behaviors in cyprinids.\nFasting/food restriction decreases CART brain expression in Cypriniformes (goldfish Volkoff and Peter, 2001a, zebrafish Nishio et al., 2012; Guillot et al., 2016 and common carp, Wan et al., 2012), most Characiformes (red-bellied piranha Volkoff, 2014a, and pacu Volkoff et al., 2017), most Salmoniformes (Atlantic salmon, Murashita et al., 2009a; Kousoulaki et al., 2013, rainbow trout Figueiredo-Silva et al., 2012), Atlantic cod (Kehoe and Volkoff, 2007), cunner (Perciforme) (Babichuk and Volkoff, 2013), medaka (CART3) (Murashita and Kurokawa, 2011), and Siluriformes (channel catfish Kobayashi et al., 2008, African sharptooth catfish Clarias gariepinus Subhedar et al., 2011), suggesting an anorexigenic role for CART in teleost fish. Postprandial increases in CART brain expression have been shown in Senegalese sole (CART1a, CART 2a and CART4) (Bonacic et al., 2015), pacu (Volkoff et al., 2017), dourado (Volkoff et al., 2016), channel catfish (Peterson et al., 2012) but not in cod (Kehoe and Volkoff, 2007).\nHowever, in Arctic charr, CART hypothalamic expression is similar throughout the seasonal feeding cycles (Striberny et al., 2015) and fasting does not affect CART expression in either dourado (Volkoff et al., 2016), winter flounder (MacDonald and Volkoff, 2009a) or Atlantic halibut larvae (Gomes et al., 2015), and in lake trout, fish exposed to the pesticide tebufenozide and control fish have similar food intakes, despite higher CART mRNA brain expression levels in exposed fish (Volkoff et al., 2007). In winter skate, 2 weeks of fasting have no effects on brain CART expression (MacDonald and Volkoff, 2009b), suggesting that CART might not have a major feeding-regulating role in elasmobranchs.\nCART expression does not appear to be affected by diet, as in both cod fed a camelina (plant) diet (Tuziak et al., 2014) or rotifers or zooplankton (Katan et al., 2016) and pacu fed soybean concentrate (Volkoff et al., 2017), similar CART brain expression are seen between experimental and control fish.\nOverall, there is a large interspecific variation in the number of forms and responses to fasting in the CART system in fish, although most studies tend to show that CART is mostly a central factor that might act as an appetite inhibitor.\n\nPro-opiomelanocortin (POMC) family of peptides\nProopiomelanocortin (POMC) is a common precursor that is processed post-translationally to generate melanocortin peptides [α-, β-, and γ-melanocyte-stimulating hormone (α-, β-, γ-MSH)], adrenocorticotropic hormone (ACTH) and other hormones that include β-endorphin (β-END) and β-lipotropic hormone (β-LPH) (Adan et al., 2006; Takahashi, 2016). POMC is mainly produced in the vertebrate pituitary, but is also found in brain, in particular the arcuate nucleus (ARC) of the hypothalamus. Receptors for melanocortin peptides include five subtypes (MC1R- MC5R) (Takahashi, 2016). In mammals, POMC and α-MSH have been shown to be involved in the regulation of appetite and energy homeostasis: POMC neurons suppress appetite by releasing α-MSH, which is an agonist at the anorectic melanocortin-4 receptor (MC4R) (Adan et al., 2006; Cone, 2006; Sohn, 2015).\nTeleost fish lack γ-MSH and the POMC gene encodes an extra MSH (δ-MSH) in elasmobranchs (Cérda-Reverter et al., 2011). Fish POMC was first identified in Salmoniformes (Kawauchi, 1983; Kitahara et al., 1988) and Cypriniformes (Arends et al., 1998), followed by the identification of several forms in other fish species. As in other vertebrates, fish POMC is mainly expressed in the pituitary gland, but also within the lateral tuberal nucleus, which is equivalent to the mammalian ARC (Cérda-Reverter et al., 2011). POMC, α-MSH and the MC4R have been shown to regulate feeding in a few fish species.\nIn goldfish, fasting does not seem to affect hypothalamic POMC mRNA expression levels (Cerdá-Reverter et al., 2003), but ICV administration of [Nle4, d-Phe7]- α-MSH, a melanocortin agonist, inhibits food intake (Cerdá-Reverter et al., 2003), suggesting the melanocortin system participates in central regulation of food intake in Cypriniformes (Cerdá-Reverter et al., 2003). In addition, ICV injections of a MSH (MC4R) receptor agonist (melanotan II) suppress hypothalamic NPY expression (Kojima et al., 2010), and hypothalamic α-MSH-containing neurons are in close contact to NPY-containing nerve fibers, suggesting that the anorexigenic actions of the melanocortin system are mediated in part by an inhibition of the NPY system. In zebrafish larvae, although early ISH studies could not detect fasting-induced changes in hypothalamic POMC transcript levels (Song et al., 2003), more recent qPCR studies indicate that POMCa expression decreases in starved fish (Shanshan et al., 2016). In addition, GH-transgenic zebrafish, who have increased feeding, display down-regulation of POMC (Dalmolin et al., 2015), consistent with an anorexigenic role for POMC-derived peptides in Cypriniformes.\nSimilarly, in salmonids, POMC/α-MSH appears to have an anorexigenic role. In coho salmon, IP injections of α-MSH decrease food intake (White et al., 2016), in rainbow trout, fasting induces a decrease in hypothalamic expression of POMC-A1 (but not POMC-A2 or POMC-B) (Leder and Silverstein, 2006), and in Atlantic salmon, expression of both POMC-A1 and POMC-B increase after feeding (Valen et al., 2011). Interestingly, α-MSH treatment does not affect feeding of GH-transgenic coho salmon (White et al., 2016), despite similar hypothalamic POMC and MC4R mRNA expression levels compared to non-transgenic fish (Kim et al., 2015), suggesting that the actions of α-MSH might be inhibited by high expression levels of GH and/or AgRP.\nIn both olive (Kang and Kim, 2015) and Barfin flounder (Takahashi et al., 2005) (Pleuronectiformes), pituitary POMC-C (isoforms 1, 2, and 3) mRNAs are not affected by fasting, suggesting pituitary POMC might not directly related to appetite regulation. However, in fasted halibut larvae, whole brain POMC-C mRNA expression is higher in unfed fish 30 min after re-feeding compared to continuously fed fish (Gomes et al., 2015), suggesting a short-term regulation of appetite. Given the small number of studies available, and the variation in experimental protocols (adults vs. larvae, pituitary vs. brain, long-term vs. short-term feeding), conclusions are difficult to drawn regarding the role of POMC in flatfish."}

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"id":"27965528-15804516-38190691","span":{"begin":8119,"end":8123},"obj":"15804516"},{"id":"27965528-25624165-38190692","span":{"begin":8465,"end":8469},"obj":"25624165"}],"text":"Anorexigenic factors\n\nCART\nCART is a peptide which transcript expression is regulated by administration of cocaine or amphetamine in rodents (Vicentic and Jones, 2007; Subhedar et al., 2014) and amphetamine in goldfish (Volkoff, 2013). CART acts as an anorexigenic factor in mammals (Larsen and Hunter, 2006), and was first identified and shown to be anorexigenic in goldfish (Volkoff and Peter, 2000, 2001a).\nTwo CART isoforms have been identified in goldfish (Volkoff and Peter, 2001a) and common carp (Wan et al., 2012), and 4 in zebrafish (Akash et al., 2014) whereas, to date, only one form has been isolated for grass carp (Zhou et al., 2013; Liu et al., 2014), Characiformes [pirapitinga (serrasalmidae) (Volkoff, 2015a), pacu (serrasasalmidae) (Volkoff et al., 2017) and dourado (characidae) (Volkoff et al., 2016), red bellied piranha (serrasalmidae) (Volkoff, 2014a)], Salmoniformes [Atlantic salmon (Murashita et al., 2009a), rainbow trout (Figueiredo-Silva et al., 2012), Arctic charr (Striberny et al., 2015) and lake trout (Salvelinus namaycush) (Volkoff et al., 2007)], Siluriformes (channel catfish Kobayashi et al., 2008), Gadiformes (Atlantic cod Kehoe and Volkoff, 2007), Perciformes (cunner Babichuk and Volkoff, 2013), winter flounder (MacDonald and Volkoff, 2009a) and Atlantic halibut (Hippoglossus hippoglossus) (Gomes et al., 2015) (Pleuronectiformes), venomous toadfish Thalassophryne nattereri (Batrachoidiforme) (Magalhaes et al., 2006), rainbow smelt (Osmerus mordax) (Osmeriforme), pufferfishes (Takifugu rubripes and Tetraodon nigroviridis, Tetraodontiforme) and stickleback Gasterosteus aculeatus (Gasterosteiforme) (cited in Murashita et al., 2009a). However, six forms of CART have been identified in the medaka (Beloniforme) (Murashita and Kurokawa, 2011) and seven forms in Senegalese sole Solea senegalensis (Pleuronectiforme), the highest number of CART genes reported to date in a vertebrate species (Bonacic et al., 2015). The only elasmobranch CART identified to date is that of winter skate (Rajiforme) (MacDonald and Volkoff, 2009b).\nCART injections induce a decrease in food intake and an increase in locomotion in goldfish (Volkoff and Peter, 2000) and enhance responsiveness to sensory stimuli in zebrafish larvae (Woods et al., 2014), suggesting that CART is involved in feeding/searching behaviors in cyprinids.\nFasting/food restriction decreases CART brain expression in Cypriniformes (goldfish Volkoff and Peter, 2001a, zebrafish Nishio et al., 2012; Guillot et al., 2016 and common carp, Wan et al., 2012), most Characiformes (red-bellied piranha Volkoff, 2014a, and pacu Volkoff et al., 2017), most Salmoniformes (Atlantic salmon, Murashita et al., 2009a; Kousoulaki et al., 2013, rainbow trout Figueiredo-Silva et al., 2012), Atlantic cod (Kehoe and Volkoff, 2007), cunner (Perciforme) (Babichuk and Volkoff, 2013), medaka (CART3) (Murashita and Kurokawa, 2011), and Siluriformes (channel catfish Kobayashi et al., 2008, African sharptooth catfish Clarias gariepinus Subhedar et al., 2011), suggesting an anorexigenic role for CART in teleost fish. Postprandial increases in CART brain expression have been shown in Senegalese sole (CART1a, CART 2a and CART4) (Bonacic et al., 2015), pacu (Volkoff et al., 2017), dourado (Volkoff et al., 2016), channel catfish (Peterson et al., 2012) but not in cod (Kehoe and Volkoff, 2007).\nHowever, in Arctic charr, CART hypothalamic expression is similar throughout the seasonal feeding cycles (Striberny et al., 2015) and fasting does not affect CART expression in either dourado (Volkoff et al., 2016), winter flounder (MacDonald and Volkoff, 2009a) or Atlantic halibut larvae (Gomes et al., 2015), and in lake trout, fish exposed to the pesticide tebufenozide and control fish have similar food intakes, despite higher CART mRNA brain expression levels in exposed fish (Volkoff et al., 2007). In winter skate, 2 weeks of fasting have no effects on brain CART expression (MacDonald and Volkoff, 2009b), suggesting that CART might not have a major feeding-regulating role in elasmobranchs.\nCART expression does not appear to be affected by diet, as in both cod fed a camelina (plant) diet (Tuziak et al., 2014) or rotifers or zooplankton (Katan et al., 2016) and pacu fed soybean concentrate (Volkoff et al., 2017), similar CART brain expression are seen between experimental and control fish.\nOverall, there is a large interspecific variation in the number of forms and responses to fasting in the CART system in fish, although most studies tend to show that CART is mostly a central factor that might act as an appetite inhibitor.\n\nPro-opiomelanocortin (POMC) family of peptides\nProopiomelanocortin (POMC) is a common precursor that is processed post-translationally to generate melanocortin peptides [α-, β-, and γ-melanocyte-stimulating hormone (α-, β-, γ-MSH)], adrenocorticotropic hormone (ACTH) and other hormones that include β-endorphin (β-END) and β-lipotropic hormone (β-LPH) (Adan et al., 2006; Takahashi, 2016). POMC is mainly produced in the vertebrate pituitary, but is also found in brain, in particular the arcuate nucleus (ARC) of the hypothalamus. Receptors for melanocortin peptides include five subtypes (MC1R- MC5R) (Takahashi, 2016). In mammals, POMC and α-MSH have been shown to be involved in the regulation of appetite and energy homeostasis: POMC neurons suppress appetite by releasing α-MSH, which is an agonist at the anorectic melanocortin-4 receptor (MC4R) (Adan et al., 2006; Cone, 2006; Sohn, 2015).\nTeleost fish lack γ-MSH and the POMC gene encodes an extra MSH (δ-MSH) in elasmobranchs (Cérda-Reverter et al., 2011). Fish POMC was first identified in Salmoniformes (Kawauchi, 1983; Kitahara et al., 1988) and Cypriniformes (Arends et al., 1998), followed by the identification of several forms in other fish species. As in other vertebrates, fish POMC is mainly expressed in the pituitary gland, but also within the lateral tuberal nucleus, which is equivalent to the mammalian ARC (Cérda-Reverter et al., 2011). POMC, α-MSH and the MC4R have been shown to regulate feeding in a few fish species.\nIn goldfish, fasting does not seem to affect hypothalamic POMC mRNA expression levels (Cerdá-Reverter et al., 2003), but ICV administration of [Nle4, d-Phe7]- α-MSH, a melanocortin agonist, inhibits food intake (Cerdá-Reverter et al., 2003), suggesting the melanocortin system participates in central regulation of food intake in Cypriniformes (Cerdá-Reverter et al., 2003). In addition, ICV injections of a MSH (MC4R) receptor agonist (melanotan II) suppress hypothalamic NPY expression (Kojima et al., 2010), and hypothalamic α-MSH-containing neurons are in close contact to NPY-containing nerve fibers, suggesting that the anorexigenic actions of the melanocortin system are mediated in part by an inhibition of the NPY system. In zebrafish larvae, although early ISH studies could not detect fasting-induced changes in hypothalamic POMC transcript levels (Song et al., 2003), more recent qPCR studies indicate that POMCa expression decreases in starved fish (Shanshan et al., 2016). In addition, GH-transgenic zebrafish, who have increased feeding, display down-regulation of POMC (Dalmolin et al., 2015), consistent with an anorexigenic role for POMC-derived peptides in Cypriniformes.\nSimilarly, in salmonids, POMC/α-MSH appears to have an anorexigenic role. In coho salmon, IP injections of α-MSH decrease food intake (White et al., 2016), in rainbow trout, fasting induces a decrease in hypothalamic expression of POMC-A1 (but not POMC-A2 or POMC-B) (Leder and Silverstein, 2006), and in Atlantic salmon, expression of both POMC-A1 and POMC-B increase after feeding (Valen et al., 2011). Interestingly, α-MSH treatment does not affect feeding of GH-transgenic coho salmon (White et al., 2016), despite similar hypothalamic POMC and MC4R mRNA expression levels compared to non-transgenic fish (Kim et al., 2015), suggesting that the actions of α-MSH might be inhibited by high expression levels of GH and/or AgRP.\nIn both olive (Kang and Kim, 2015) and Barfin flounder (Takahashi et al., 2005) (Pleuronectiformes), pituitary POMC-C (isoforms 1, 2, and 3) mRNAs are not affected by fasting, suggesting pituitary POMC might not directly related to appetite regulation. However, in fasted halibut larvae, whole brain POMC-C mRNA expression is higher in unfed fish 30 min after re-feeding compared to continuously fed fish (Gomes et al., 2015), suggesting a short-term regulation of appetite. Given the small number of studies available, and the variation in experimental protocols (adults vs. larvae, pituitary vs. brain, long-term vs. short-term feeding), conclusions are difficult to drawn regarding the role of POMC in flatfish."}