%0 Journal Article %J Frontiers in Endocrinology %D 2022 %T New Insights Into the Evolution of Corticotropin-Releasing Hormone Family With a Special Focus on Teleosts %A Maugars, Gersende %A Mauvois, Xavier %A Martin, Patrick %A Rousseau, Karine %A Aroua, Salima %A Sylvie Dufour %B Frontiers in Endocrinology %V 13 %P 937218 %G eng %R Doi: 10.3389/fendo.2022.937218 %0 Journal Article %J Frontiers in Physiology %D 2022 %T Transient Receptor Potential-Vanilloid (TRPV1-TRPV4) Channels in the Atlantic Salmon, Salmo salar. A Focus on the Pineal Gland and Melatonin Production %A Nisembaum, Laura Gabriela %A Loentgen, Guillaume %A L'Honoré, Thibault %A Martin, Patrick %A Paulin, Charles-Hubert %A Fuentès, Michael %A Escoubeyrou, Karine %A Delgado, Maria Jesus %A Besseau, Laurence %A Falcón, Jack %K Atlantic salmon %K melatonin %K pineal organ %K Temperature %K transient receptor potential vanilloid (TRPV) %K TRPV1 %K TRPV4 %X Fish are ectotherm, which rely on the external temperature to regulate their internal body temperature, although some may perform partial endothermy. Together with photoperiod, temperature oscillations, contribute to synchronizing the daily and seasonal variations of fish metabolism, physiology and behavior. Recent studies are shedding light on the mechanisms of temperature sensing and behavioral thermoregulation in fish. In particular, the role of some members of the transient receptor potential channels (TRP) is being gradually unraveled. The present study in the migratory Atlantic salmon, Salmo salar, aims at identifying the tissue distribution and abundance in mRNA corresponding to the TRP of the vanilloid subfamilies, TRPV1 and TRPV4, and at characterizing their putative role in the control of the temperature-dependent modulation of melatonin production—the time-keeping hormone—by the pineal gland. In Salmo salar, TRPV1 and TRPV4 mRNA tissue distribution appeared ubiquitous; mRNA abundance varied as a function of the month investigated. In situ hybridization and immunohistochemistry indicated specific labeling located in the photoreceptor cells of the pineal gland and the retina. Additionally, TRPV analogs modulated the production of melatonin by isolated pineal glands in culture. The TRPV1 agonist induced an inhibitory response at high concentrations, while evoking a bell-shaped response (stimulatory at low, and inhibitory at high, concentrations) when added with an antagonist. The TRPV4 agonist was stimulatory at the highest concentration used. Altogether, the present results agree with the known widespread distribution and role of TRPV1 and TRPV4 channels, and with published data on trout (Oncorhynchus mykiss), leading to suggest these channels mediate the effects of temperature on S. salar pineal melatonin production. We discuss their involvement in controlling the timing of daily and seasonal events in this migratory species, in the context of an increasing warming of water temperatures. %B Frontiers in Physiology %V 22 %P 15 %8 01/2022 %G eng %U https://www.frontiersin.org/articles/10.3389/fphys.2021.784416/full?&utm_source=Email_to_authors_&utm_medium=Email&utm_content=T1_11.5e1_author&utm_campaign=Email_publication&field=&journalName=Frontiers_in_Physiology&id=784416 %N 784416 %9 original research %R 10.3389/fphys.2021.784416 %0 Journal Article %J Journal of Neuroendocrinology %D 2021 %T Melatonin and osmoregulation in fish: A focus on Atlantic salmon Salmo salar smoltification %A Nisembaum, Laura Gabriela %A Martin, Patrick %A Lecomte, Frédéric %A Falcón, Jack %X Part of the life cycle of several fish species includes important salinity changes, as is the case for the sea bass (Dicentrarchus labrax) or the Atlantic salmon (Salmo salar). Salmo salar juveniles migrate downstream from their spawning sites to reach seawater, where they grow and become sexually mature. The process of preparation enabling juveniles to migrate downstream and physiologically adapt to seawater is called smoltification. Daily and seasonal variations of photoperiod and temperature play a role in defining the timing of smoltification, which may take weeks to months, depending on the river length and latitude. Smoltification is characterised by a series of biochemical, physiological and behavioural changes within the neuroendocrine axis. This review discusses the current knowledge and gaps related to the neuroendocrine mechanisms that mediate the effects of light and temperature on smoltification. Studies performed in S. salar and other salmonids, as well as in other species undergoing important salinity changes, are reviewed, and a particular emphasis is given to the pineal hormone melatonin and its possible role in osmoregulation. The daily and annual variations of plasma melatonin levels reflect corresponding changes in external photoperiod and temperature, which suggests that the hormonal time‐keeper melatonin might contribute to controlling smoltification. Here, we review studies on (i) the impact of pinealectomy and/or melatonin administration on smoltification; (ii) melatonin interactions with hormones involved in osmoregulation (e.g., prolactin, growth hormone and cortisol); (iii) the presence of melatonin receptors in tissues involved in osmoregulation; and (iv) the impacts of salinity changes on melatonin receptors and circulating melatonin levels. Altogether, these studies show evidence indicating that melatonin interacts with the neuroendocrine pathways controlling smoltification, although more information is needed to clearly decipher its mechanisms of action. %B Journal of Neuroendocrinology %V 33 %8 Jan-03-2021 %G eng %U https://onlinelibrary.wiley.com/toc/13652826/33/3 %N 3 %! J Neuroendocrinol %R https://doi.org/10.1111/jne.12955 %0 Journal Article %J Frontiers in Endocrinology %D 2020 %T Differential Regulation of the Expression of the Two Thyrotropin Beta Subunit Paralogs by Salmon Pituitary Cells In Vitro %A Fleming, Mitchell Stewart %A Maugars, Gersende %A Martin, Patrick %A Sylvie Dufour %A Rousseau, Karine %B Frontiers in Endocrinology %V 11 %8 Mar-11-2022 %G eng %U https://www.frontiersin.org/articles/10.3389/fendo.2020.603538/full %! Front. Endocrinol. %R 10.3389/fendo.2020.603538 %0 Journal Article %J Journal of Comparative Physiology B %D 2020 %T Effects of a temperature rise on Atlantic salmon, Salmo salar, melatonin and thyroid hormones during smoltification %A Nisembaum, Laura Gabriela %A Martin, Patrick %A Fuentès, Michael %A Besseau, Laurence %A Magnanou, Elodie %A McCormick, Stephen D %A Jack Falcon %K Atlantic salmon %K melatonin %K smoltification %K Temperature %K thyroid hormones %X Smoltification prepares juvenile Atlantic salmon (Salmo salar) for downstream migration. Dramatic changes characterize this crucial event in the fish life cycle, including gills’ Na+/K+-ATPase activity (NKA) and plasma hormonal levels. The triggering of smoltification relies on photoperiod and is modulated by temperature. Both provide reliable information, to which fish adapted for thousands of years, that allows deciphering daily and calendar time. Here we studied the impact of different photoperiod (natural, sustained winter solstice) and temperature (natural, ~ +4°C) combinations, on gills’ NKA, plasma free triiodothyronine (T3), thyroxine (T4) and melatonin (MEL; the time-keeping hormone), throughout smoltification. We also studied the impact of temperature history on pineal gland MEL production in vitro. The spring increase in gills’ NKA was less pronounced in smolts kept under sustained winter photoperiod and/or elevated temperature. Plasma thyroid hormones levels displayed day-night variations, which were affected by elevated temperature, either independently from photoperiod (decrease in T3 levels) or under natural photoperiod exclusively (increase in T4 nocturnal levels). Nocturnal MEL secretion was potentiated by the elevated temperature, which also altered MEL profile under sustained winter photoperiod. Temperature also affected pineal MEL production in vitro, a response that depended on previous environmental acclimation of the organ. The results support the view that the salmon pineal is a photoperiod and temperature sensor, highlight the complexity of the interaction of these environmental factors on S. salar endocrine system, and suggest that climate change might compromise salmon’s time “deciphering” and processes such as smoltification, downstream migration and seawater residence. %B Journal of Comparative Physiology B %V 190 %P 731-748 %8 09/2020 %G eng %U https://link.springer.com/article/10.1007/s00360-020-01304-2 %9 ACL %R 10.1007/s00360-020-01304-2 %0 Journal Article %J J Comp Physiol B %D 2020 %T Effects of a temperature rise on melatonin and thyroid hormones during smoltification of Atlantic salmon, Salmo salar %A Nisembaum, Laura Gabriela %A Martin, Patrick %A Fuentès, M %A Besseau, Laurence %A Magnanou, Elodie %A McCormick, Stephen %A Falcón, Jack %K Atlantic salmon %K melatonin %K Temperature %K thyroid hormones %X Smoltification prepares juvenile Atlantic salmon (Salmo salar) for downstream migration. Dramatic changes characterize this crucial event in the salmon’s life cycle, including increased gill Na+/K+-ATPase activity (NKA) and plasma hormone levels. The triggering of smoltification relies on photoperiod and is modulated by temperature. Both provide reliable information, to which fish have adapted for thousands of years, that allows deciphering daily and calendar time. Here we studied the impact of different photoperiod (natural, sustained winter solstice) and temperature (natural, ~ + 4° C) combinations, on gill NKA, plasma free triiodothyronine (T3) and thyroxine (T4), and melatonin (MEL; the time-keeping hormone), throughout smoltification. We also studied the impact of temperature history on pineal gland MEL production in vitro. The spring increase in gill NKA was less pronounced in smolts kept under sustained winter photoperiod and/or elevated temperature. Plasma thyroid hormone levels displayed day–night variations, which were affected by elevated temperature, either independently from photoperiod (decrease in T3 levels) or under natural photoperiod exclusively (increase in T4 nocturnal levels). Nocturnal MEL secretion was potentiated by the elevated temperature, which also altered the MEL profile under sustained winter photoperiod. Temperature also affected pineal MEL production in vitro, a response that depended on previous environmental acclimation of the organ. The results support the view that the salmon pineal is a photoperiod and temperature sensor, highlight the complexity of the interaction of these environmental factors on the endocrine system of S. salar, and indicate that climate change might compromise salmon’s time “deciphering” during smoltification, downstream migration and seawater residence. %B J Comp Physiol B %8 03 September 202 %G eng %U https://link.springer.com/article/10.1007%2Fs00360-020-01304-2 %9 Journal Article %R 10.1007/s00360-020-01304-2 %0 Journal Article %J Scientific Reports %D 2019 %T Functional divergence of thyrotropin beta-subunit paralogs gives new insights into salmon smoltification metamorphosis %A Fleming, Mitchell S %A Maugars, Gersende %A Lafont, Anne-Gaelle %A Rancon, Jocelyn %A Fontaine, Romain %A Nourizadeh-Lillabadi, Rasoul %A Weltzien, Finn-Arne %A Santidrian Yebra-Pimentel, Elena %A Dirks, Ron %A McCormick, Stephen D %A Rousseau, Karine %A Martin, Patrick %A Sylvie Dufour %B Scientific Reports %V 9 %P 4561 %G eng %M doi.org/10.1038/s41598-019-40019-5