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Chevillard PM, Batailler M, Piégu B, Estienne A, Blache MC, Dubois JP, Pillon D, Vaudin P, Dupont J, Just N, Migaud M. Seasonal vascular plasticity in the mediobasal hypothalamus of the adult ewe. Histochem Cell Biol 2022; 157:581-593. [PMID: 35118552 DOI: 10.1007/s00418-022-02079-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2022] [Indexed: 12/16/2022]
Abstract
Sheep, like most seasonal mammals, exhibit a cyclic adaptive reproductive physiology that allows ewes to give birth to their progeny during the spring when environmental conditions are favorable to their survival. This process relies on the detection of day length (or photoperiod) and is associated with profound changes in cellular plasticity and gene expression in the hypothalamic-pituitary-gonadal axis, mechanisms that are suggested to participate in the seasonal adaptation of neuroendocrine circuits. Recently, pituitary vascular growth has been proposed as a seasonally regulated process in which the vascular endothelial growth factor A (VEGFA), a well-known angiogenic cytokine, is suspected to play a crucial role. However, whether this mechanism is restricted to the pituitary gland or also occurs in the mediobasal hypothalamus (MBH), a crucial contributor to the control of the reproductive function, remains unexplored. Using newly developed image analysis tools, we showed that the arcuate nucleus (ARH) of the MBH exhibits an enhanced vascular density during the long photoperiod or non-breeding season, associated with higher expression of VEGFA. In the median eminence (ME), a structure connecting the MBH to the pituitary gland, higher VEGFA, kinase insert domain receptor (KDR/VEGFR2) and plasmalemma vesicle-associated protein (PLVAP) gene expressions were detected during the long photoperiod. We also found that VEGFA and its receptor, VEGFR2, are expressed by neurons and tanycytes in both the ARH and ME. Altogether, these data show variations in the MBH vasculature according to seasons potentially through a VEGFA-dependent pathway, paving the way for future studies aiming to decipher the role of these changes in the hypothalamic control of seasonal reproduction.
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Affiliation(s)
- Pierre-Marie Chevillard
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Martine Batailler
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Benoît Piégu
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Anthony Estienne
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Marie-Claire Blache
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Jean-Philippe Dubois
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Delphine Pillon
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Pascal Vaudin
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Joëlle Dupont
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Nathalie Just
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France
| | - Martine Migaud
- Physiologie de la Reproduction et des Comportements PRC Centre INRAE Val de Loire, CNRS, IFCE, INRAE, Université de Tours, 37380, Nouzilly, France.
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2
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Poissenot K, Moussu C, Chesneau D, Ramadier E, Abi Khalil R, Chorfa A, Chemineau P, Michelin Y, Saez F, Drevet J, Benoit E, Lattard V, Pinot A, Dardente H, Keller M. Field study reveals morphological and neuroendocrine correlates of seasonal breeding in female water voles, Arvicola terrestris. Gen Comp Endocrinol 2021; 311:113853. [PMID: 34265346 DOI: 10.1016/j.ygcen.2021.113853] [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: 12/02/2020] [Revised: 07/04/2021] [Accepted: 07/09/2021] [Indexed: 12/18/2022]
Abstract
Seasonally breeding mammals display timely physiological switches between reproductive activity and sexual rest, which ensure synchronisation of births at the most favourable time of the year. These switches correlate with seasonal changes along the hypothalamo-pituitary-gonadal axis, but they are primarily orchestrated at the hypothalamic level through environmental control of KISS1-dependent GnRH release. Our field study shows that births of fossorial water voles, Arvicola terrestris, are concentrated between March and October, which indicates the existence of an annual reproductive cycle in this species. Monthly field monitoring for over a year further reveals dramatic seasonal changes in the morphology of the ovary, uterus and lateral scent glands, which correlate with the reproductive status. Finally, we demonstrate seasonal variation in kisspeptin expression within the hypothalamic arcuate nucleus. Altogether, this study demonstrates a marked rhythm of seasonal breeding in the water vole and we speculate that this is governed by seasonal changes in photoperiod.
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Affiliation(s)
- Kévin Poissenot
- CNRS, IFCE, INRAE, Université de Tours, PRC, F-37380 Nouzilly, France
| | - Chantal Moussu
- CNRS, IFCE, INRAE, Université de Tours, PRC, F-37380 Nouzilly, France
| | - Didier Chesneau
- CNRS, IFCE, INRAE, Université de Tours, PRC, F-37380 Nouzilly, France
| | - Etienne Ramadier
- UMR 0874 UREP, VetAgro Sup, INRAE, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Rami Abi Khalil
- USC 1233 RS2GP, INRAE, VetAgro Sup, Université de Lyon, F-69280 Marcy l'Etoile, France
| | - Areski Chorfa
- GReD Laboratory, CNRS UMR 6293 - INSERM U1103 - Université Clermont Auvergne, 28 place Henri Dunant, 63001 Clermont-Ferrand Cedex, France
| | | | - Yves Michelin
- UMR Territoires, VetagroSup, INRAE, AgroParisTech, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Fabrice Saez
- GReD Laboratory, CNRS UMR 6293 - INSERM U1103 - Université Clermont Auvergne, 28 place Henri Dunant, 63001 Clermont-Ferrand Cedex, France
| | - Joël Drevet
- GReD Laboratory, CNRS UMR 6293 - INSERM U1103 - Université Clermont Auvergne, 28 place Henri Dunant, 63001 Clermont-Ferrand Cedex, France
| | - Etienne Benoit
- USC 1233 RS2GP, INRAE, VetAgro Sup, Université de Lyon, F-69280 Marcy l'Etoile, France
| | - Virginie Lattard
- USC 1233 RS2GP, INRAE, VetAgro Sup, Université de Lyon, F-69280 Marcy l'Etoile, France
| | - Adrien Pinot
- UMR 0874 UREP, VetAgro Sup, INRAE, Université Clermont Auvergne, Clermont-Ferrand, France; USC 1233 RS2GP, INRAE, VetAgro Sup, Université de Lyon, F-69280 Marcy l'Etoile, France
| | - Hugues Dardente
- CNRS, IFCE, INRAE, Université de Tours, PRC, F-37380 Nouzilly, France
| | - Matthieu Keller
- CNRS, IFCE, INRAE, Université de Tours, PRC, F-37380 Nouzilly, France.
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3
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Uemura A, Fruttiger M, D'Amore PA, De Falco S, Joussen AM, Sennlaub F, Brunck LR, Johnson KT, Lambrou GN, Rittenhouse KD, Langmann T. VEGFR1 signaling in retinal angiogenesis and microinflammation. Prog Retin Eye Res 2021; 84:100954. [PMID: 33640465 PMCID: PMC8385046 DOI: 10.1016/j.preteyeres.2021.100954] [Citation(s) in RCA: 146] [Impact Index Per Article: 48.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 02/12/2021] [Accepted: 02/19/2021] [Indexed: 12/13/2022]
Abstract
Five vascular endothelial growth factor receptor (VEGFR) ligands (VEGF-A, -B, -C, -D, and placental growth factor [PlGF]) constitute the VEGF family. VEGF-A binds VEGF receptors 1 and 2 (VEGFR1/2), whereas VEGF-B and PlGF only bind VEGFR1. Although much research has been conducted on VEGFR2 to elucidate its key role in retinal diseases, recent efforts have shown the importance and involvement of VEGFR1 and its family of ligands in angiogenesis, vascular permeability, and microinflammatory cascades within the retina. Expression of VEGFR1 depends on the microenvironment, is differentially regulated under hypoxic and inflammatory conditions, and it has been detected in retinal and choroidal endothelial cells, pericytes, retinal and choroidal mononuclear phagocytes (including microglia), Müller cells, photoreceptor cells, and the retinal pigment epithelium. Whilst the VEGF-A decoy function of VEGFR1 is well established, consequences of its direct signaling are less clear. VEGFR1 activation can affect vascular permeability and induce macrophage and microglia production of proinflammatory and proangiogenic mediators. However the ability of the VEGFR1 ligands (VEGF-A, PlGF, and VEGF-B) to compete against each other for receptor binding and to heterodimerize complicates our understanding of the relative contribution of VEGFR1 signaling alone toward the pathologic processes seen in diabetic retinopathy, retinal vascular occlusions, retinopathy of prematurity, and age-related macular degeneration. Clinically, anti-VEGF drugs have proven transformational in these pathologies and their impact on modulation of VEGFR1 signaling is still an opportunity-rich field for further research.
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Affiliation(s)
- Akiyoshi Uemura
- Department of Retinal Vascular Biology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho, Mizuho-ku, Nagoya, 467-8601, Japan.
| | - Marcus Fruttiger
- UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK.
| | - Patricia A D'Amore
- Schepens Eye Research Institute of Massachusetts Eye and Ear, 20 Staniford Street, Boston, MA, 02114, USA.
| | - Sandro De Falco
- Angiogenesis Laboratory, Institute of Genetics and Biophysics "Adriano Buzzati-Traverso", Via Pietro Castellino 111, 80131 Naples, Italy; ANBITION S.r.l., Via Manzoni 1, 80123, Naples, Italy.
| | - Antonia M Joussen
- Department of Ophthalmology, Charité-Universitätsmedizin Berlin, Hindenburgdamm 30, 12200 Berlin, and Augustenburger Platz 1, 13353, Berlin, Germany.
| | - Florian Sennlaub
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France.
| | - Lynne R Brunck
- Bayer Consumer Care AG, Pharmaceuticals, Peter-Merian-Strasse 84, CH-4052 Basel, Switzerland.
| | - Kristian T Johnson
- Bayer Consumer Care AG, Pharmaceuticals, Peter-Merian-Strasse 84, CH-4052 Basel, Switzerland.
| | - George N Lambrou
- Bayer Consumer Care AG, Pharmaceuticals, Peter-Merian-Strasse 84, CH-4052 Basel, Switzerland.
| | - Kay D Rittenhouse
- Bayer Consumer Care AG, Pharmaceuticals, Peter-Merian-Strasse 84, CH-4052 Basel, Switzerland.
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Joseph-Stelzmann-Str. 9, 50931, Cologne, Germany.
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Dailey W, Shunemann R, Yang F, Moore M, Knapp A, Chen P, Deshpande M, Metcalf B, Tompkins Q, Guzman AE, Felisky J, Mitton KP. Differences in activation of intracellular signaling in primary human retinal endothelial cells between isoforms of VEGFA 165. Mol Vis 2021; 27:191-205. [PMID: 33953532 PMCID: PMC8092446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 04/26/2021] [Indexed: 11/18/2022] Open
Abstract
Purpose There are reports that a b-isoform of vascular endothelial growth factor-A 165 (VEGFA165b) is predominant in normal human vitreous, switching to the a-isoform (VEGFA165a) in the vitreous of some diseased eyes. Although these isoforms appear to have a different ability to activate the VEGF receptor 2 (VEGFR2) in various endothelial cells, the nature of their ability to activate intracellular signaling pathways is not fully characterized, especially in retinal endothelial cells. We determined their activation potential for two key intracellular signaling pathways (MAPK, AKT) over complete dose-response curves and compared potential effects on the expression of several VEGFA165 target genes in primary human retinal microvascular endothelial cells (HRMECs). Methods To determine full dose-response curves for the activation of MAPK (ERK1/2), AKT, and VEGFR2, direct in-cell western assays were developed using primary HRMECs. Potential differences in dose-response effects on gene expression markers related to endothelial cell and leukocyte adhesion (ICAM1, VCAM1, and SELE) and tight junctions (CLDN5 and OCLN) were tested with quantitative PCR. Results Activation dose-response analysis revealed much stronger activation of MAPK, AKT, and VEGFR2 by the a-isoform at lower doses. MAPK activation in primary HRMECs displayed a sigmoidal dose-response to a range of VEGFA 165 a concentrations spanning 10-250 pM, which shifted higher into the 100-5,000 pM range with VEGFA 165 b. Similar maximum activation of MAPK was achieved by both isoforms at high concentrations. Maximum activation of AKT by VEGFA 165 b was only half of the maximum activation from VEGFA 165 a. At a lower intermediate dose, where VEGFA 165 a activated intracellular signaling stronger than VEGFA 165 b, the changes in VEGFA target gene expression were generally greater with VEGFA 165 a. Conclusions In primary HRMECs, VEGFA 165 a could maximally activate MAPK and AKT at lower concentrations where VEGFA 165 b had relatively little effect. The timing for maximum activation of MAPK was similar for the isoforms, which is different from that reported for non-retinal endothelial cells. Although differences in VEGFA 165 a and VEGFA 165 b are limited to the sequence of their six C-terminal six amino acids, this results in a large difference in their ability to activate at least two key intracellular signaling pathways and VEGF-target gene expression in primary human retinal endothelial cells.
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Lomet D, Robert V, Poissenot K, Beltramo M, Dardente H. No evidence that Spexin impacts LH release and seasonal breeding in the ewe. Theriogenology 2020; 158:1-7. [PMID: 32916519 DOI: 10.1016/j.theriogenology.2020.08.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/26/2020] [Accepted: 08/26/2020] [Indexed: 01/11/2023]
Abstract
Spexin (SPX) is a recently identified peptide hormone of 14 amino acids. Interestingly, Spx and Kiss1 genes share a common ancestor gene. Considering that KISS1 peptides are key controllers of breeding in mammals and circumstantial evidence that SPX regulates gonadotropins in some fish species, we hypothesized that SPX may play a KISS1-related role in sheep. Here, we cloned the ovine Spx cDNA, performed in vivo injection and infusion of SPX (i.c.v. route, with or without concomittant KISS1 presence) and assessed a potential regulation of Spx expression by season, thyroid hormone and estradiol in the medio-basal hypothalamus of the ewe. Our data do not provide support for a role of SPX in the control of the gonadotropic axis in the ewe.
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Affiliation(s)
- Didier Lomet
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
| | - Vincent Robert
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
| | - Kevin Poissenot
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
| | | | - Hugues Dardente
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France.
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Dardente H, English WR, Valluru MK, Kanthou C, Simpson D. Debunking the Myth of the Endogenous Antiangiogenic Vegfaxxxb Transcripts. Trends Endocrinol Metab 2020; 31:398-409. [PMID: 32396842 DOI: 10.1016/j.tem.2020.01.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/28/2019] [Accepted: 01/14/2020] [Indexed: 12/19/2022]
Abstract
In this opinion article we critically assess evidence for the existence of a family of antiangiogenic vascular endothelial growth factor (Vegfaxxxb) transcripts, arising from the use of a phylogenetically conserved alternative distal splice site within exon 8 of the VEGFA gene. We explain that prior evidence for Vegfaxxxb transcripts in tissues rests heavily upon flawed RT-PCR methodologies, with the extensive use of 5'-tailing in primer design being the main issue. Furthermore, our analysis of large RNA-seq data sets (human and ovine) fails to identify a single Vegfaxxxb transcript. Therefore, we challenge the very existence of Vegfaxxxb transcripts, which further questions the physiological relevance of studies based on the use of 'anti-VEGFAxxxb' antibodies. Our analysis has implications for the proposed therapeutic use of isoform-specific anti-VEGFA strategies for treating cancer and retinopathies.
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Affiliation(s)
- Hugues Dardente
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380 Nouzilly, France.
| | - William R English
- Department of Oncology and Metabolism, Tumour Microcirculation Group, University of Sheffield, School of Medicine, Beech Hill Road, Sheffield, S10 2RX, UK
| | - Manoj K Valluru
- Department of Oncology and Metabolism, Tumour Microcirculation Group, University of Sheffield, School of Medicine, Beech Hill Road, Sheffield, S10 2RX, UK
| | - Chryso Kanthou
- Department of Oncology and Metabolism, Tumour Microcirculation Group, University of Sheffield, School of Medicine, Beech Hill Road, Sheffield, S10 2RX, UK
| | - David Simpson
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, BT7 1NN, UK
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Dardente H, Lomet D, Chesneau D, Pellicer-Rubio MT, Hazlerigg D. Discontinuity in the molecular neuroendocrine response to increasing daylengths in Ile-de-France ewes: Is transient Dio2 induction a key feature of circannual timing? J Neuroendocrinol 2019; 31:e12775. [PMID: 31340078 DOI: 10.1111/jne.12775] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 07/15/2019] [Accepted: 07/17/2019] [Indexed: 12/21/2022]
Abstract
In mammals, melatonin is responsible for the synchronisation of seasonal cycles to the solar year. Melatonin is secreted by the pineal gland with a profile reflecting the duration of the night and acts via the pituitary pars tuberalis (PT), which in turn modulates hypothalamic thyroid hormone status via seasonal changes in the production of locally-acting thyrotrophin. Recently, we demonstrated that, in the Soay sheep, photoperiodic induction of Tshb expression and consequent downstream hypothalamic changes occur over a narrow range of photoperiods between 12 and 14 hours in duration. In the present study, we aimed to extend our molecular characterisation of this pathway, based on transcriptomic analysis of photoperiodic changes in the pituitary and hypothalamus of ovariectomised, oestradiol-implanted Ile-de-France ewes. We demonstrate that photoperiodic treatments applied before the winter solstice elicit two distinctive modes of accelerated reproductive switch off compared to ewes held on a simulated natural photoperiod, with shut-down occurring markedly faster on photoperiods of 13 hours or more than on photoperiods of 12 hours and less. This pattern of response was reflected in gene expression profiles of photoperiodically sensitive markers, both in the PT (Tshb, Fam150b, Vmo1, Ezh2 and Suv39H2) and in tanycytes (Tmem252 and Dct). Unexpectedly, the expression of Dio2 in tanycytes did not show any noticeable increase in expression with lengthening photoperiods. Finally, the expression of Kiss1, the key activator of gonadotrophin-releasing hormone release, was proportionately decreased by lengthening photoperiods, in a pattern that correlated strongly with gonadotrophin suppression. These data show that stepwise increases in photoperiod lead to graded molecular responses at the level of the PT, a progressive suppression of Kiss1 in the hypothalamic arcuate nucleus and luteinising hormone/follicle-stimulating hormone release by the pituitary, despite apparently unchanged Dio2 expression in tanycytes. We hypothesise that this apparent discontinuity in the seasonal neuroendocrine response illustrates the transient nature of the thyroid hormone-mediated response to long days in the control of circannual timing.
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Affiliation(s)
- Hugues Dardente
- PRC, INRA, CNRS, IFCE, Université de Tours, Nouzilly, France
| | - Didier Lomet
- PRC, INRA, CNRS, IFCE, Université de Tours, Nouzilly, France
| | - Didier Chesneau
- PRC, INRA, CNRS, IFCE, Université de Tours, Nouzilly, France
| | | | - David Hazlerigg
- Department of Arctic and Marine Biology, University of Tromsø, Tromsø, Norway
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Dardente H, Lomet D. Photoperiod and thyroid hormone regulate expression of l-dopachrome tautomerase (Dct), a melanocyte stem-cell marker, in tanycytes of the ovine hypothalamus. J Neuroendocrinol 2018; 30:e12640. [PMID: 30129070 DOI: 10.1111/jne.12640] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 08/16/2018] [Indexed: 12/16/2022]
Abstract
The pars tuberalis (PT) of the pituitary is central to the control of seasonal breeding. In mammals, the PT translates the photoperiodic message carried by melatonin into an endocrine thyroid-stimulating hormone output, which controls local thyroid hormone (TH) signalling in tanycytes of the neighbouring hypothalamus. In the present study, we identify l-dopachrome tautomerase (Dct) as a novel marker of ovine tanycytes and show that Dct displays marked seasonal variations in expression, with higher levels during spring and summer. This seasonal profile is photoperiod-dependent because an acute exposure to long days induces Dct expression. In addition, we find that TH also modulates Dct expression. DCT functions as an enzyme in the melanin synthesis pathway within skin melanocytes, whereas expression in other tissues is comparatively low. We demonstrate that both Tyr and Tyrp1, which are enzymes that intervene upstream and downstream of Dct in the melanin synthesis pathway, respectively, are expressed at very low levels in the ovine hypothalamus. This suggests that Dct in tanycytes may not be involved in melanin synthesis. We speculate that DCT function is linked to its protective role towards oxidative stress and/or its function in the control of neural progenitor cell proliferation.
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Affiliation(s)
- Hugues Dardente
- PRC, INRA, CNRS, IFCE, Université de Tours, Nouzilly, France
| | - Didier Lomet
- PRC, INRA, CNRS, IFCE, Université de Tours, Nouzilly, France
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