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1. Estrogenic regulation of claudin 5 and tight junction protein 1 gene expression in zebrafish: A role on blood–brain barrier?

Author

Pellegrini, Elisabeth, Fernezelian, Danielle, Malleret, Cassandra, Gueguen, Marie‐Madeleine, Patche‐Firmin, Jessica, Rastegar, Sepand, Meilhac, Olivier, and Diotel, Nicolas

Abstract

The blood–brain barrier (BBB) is a physical interface between the blood and the brain parenchyma, playing key roles in brain homeostasis. In mammals, the BBB is established thanks to tight junctions between cerebral endothelial cells, involving claudin, occludin, and zonula occludens proteins. Estrogens have been documented to modulate BBB permeability. Interestingly, in the brain of zebrafish, the estrogen‐synthesizing activity is strong due to the high expression of Aromatase B protein, encoded by the cyp19a1b gene, in radial glial cells (neural stem cells). Given the roles of estrogens in BBB function, we investigated their impact on the expression of genes involved in BBB tight junctions. We treated zebrafish embryos and adult males with 17β‐estradiol and observed an increased cerebral expression of tight junction and claudin 5 genes in adult males only. In females, treatment with the nuclear estrogen receptor antagonist (ICI182,780) had no impact. Interestingly, telencephalic injuries performed in males decreased tight junction gene expression that was partially reversed with 17β‐estradiol. This was further confirmed by extravasation experiments of Evans blue showing that estrogenic treatment limits BBB leakage. We also highlighted the intimate links between endothelial cells and neural stem cells, suggesting that cholesterol and peripheral steroids could be taken up by endothelial cells and used as precursors for estrogen synthesis by neural stem cells. Together, our results show that zebrafish provides an alternative model to further investigate the role of steroids on the expression of genes involved in BBB integrity, both in constitutive and regenerative physiological conditions. The link we described between capillaries endothelial cells and steroidogenic neural cells encourages the use of this model in understanding the mechanisms by which peripheral steroids get into neural tissue and modulate neurogenic activity. [ABSTRACT FROM AUTHOR]

Published
2023
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10. Morpho-Functional Features of the Gonads of Danio rerio : the Role of Brain-Derived Neurotrophic Factor

Author

CACIALLI, PIETRO, D'Angelo, Livia, de Girolamo, Paolo, Avallone, Luigi, Lucini, Carla, Pellegrini, Elisabeth, Castaldo, Luciana, University of Naples Federico II = Università degli studi di Napoli Federico II, UFR Sciences de la vie et de l'environnement, Université de Rennes (UR), Cacialli, Pietro, D'Angelo, Livia, de Girolamo, Paolo, Avallone, Luigi, Lucini, Carla, Pellegrini, Elisabeth, and Castaldo, Luciana

Subjects
Male, p75, endocrine system, Histology, gonad, Receptor, Nerve Growth Factor, Testis, [SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate Zoology, Animals, Receptor, trkB, gonads, RNA, Messenger, Ecology, Evolution, Behavior and Systematics, [SDV.BDD.GAM]Life Sciences [q-bio]/Development Biology/Gametogenesis, Sertoli Cells, Brain-Derived Neurotrophic Factor, Ovary, TrkB, zebrafish, Spermatogonia, BDNF, nervous system, Oocytes, Female, Anatomy, Biotechnology
Abstract

Zebrafish, a suitable and widely used teleost fish model in basic biomedical research, displays morphophysiological features of adult gonads that share some commonalities with those of mammalian species. In mammals, gametogenesis is regulated, among several factors, by brain-derived neurotrophic factor (BDNF). This neurotrophin has a well-established role in the developing and adult nervous system, as well as gonads development and functions in vertebrate species. We hypothesize that BDNF has a role also in the gonadal functions of zebrafish. At this purpose, we investigated BDNF and its receptors p75 and TrkB in the ovary and testis of adult zebrafish, kept under laboratory conditions. Our results display (1) the expression of BDNF mRNA and pro-BDNF protein outside of the nervous system, specifically in the ovary and testis; (2) the presence of pro-BDNF in primary oocytes and follicular layer, and p75 in follicular cells; (3) the localization of pro-BDNF in type B spermatogonia, and Sertoli cells in testis. Altogether, these data lead us to consider that BDNF is involved in the gonadal function of adult zebrafish, and mainly in the adult ovary. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 301:140-147, 2018. © 2017 Wiley Periodicals, Inc.

Published
2018
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20. Impacts of bisphenol A analogues on zebrafish post‐embryonic brain.

Author

Coumailleau, Pascal, Trempont, Sarah, Pellegrini, Elisabeth, and Charlier, Thierry D.

Subjects
PREOPTIC area, MUSCULOSKELETAL system, NEUROGLIA, AROMATASE, NEURONS
Abstract

Bisphenol A (BPA) is a widely studied and well‐recognised endocrine‐disrupting chemical, and one of the current issues is its safe replacement by various analogues. Using larva zebrafish as a model, the present study reveals that moderate and chronic exposure to BPA analogues such as bisphenol S, bisphenol F and bisphenol AF may also affect vertebrate neurodevelopment and locomotor activity. Several parameters of embryo‐larval development were investigated, such as mortality, hatching, number of mitotically active cell, as defined by 5‐bromo‐2'‐deoxyuridine incorporation and proliferative cell nuclear antigen labelling, aromatase B protein expression in radial glial cell and locomotor activity. Our results show that exposure to several bisphenol analogues induced an acceleration of embryo hatching rate. At the level of the developing brain, a strong up‐regulation of the oestrogen‐sensitive Aromatase B was also detected in the hypothalamic region. This up‐regulation was not associated with effects on the numbers of mitotically active progenitors nor differentiated neurones in the preoptic area and in the nuclear recessus posterior of the hypothalamus zebrafish larvae. Furthermore, using a high‐throughput video tracking system to monitor locomotor activity in zebrafish larvae, we show that some bisphenol analogues, such as bisphenol AF, significantly reduced locomotor activity following 6 days of exposure. Taken together, our study provides evidence that BPA analogues can also affect the neurobehavioural development of zebrafish. [ABSTRACT FROM AUTHOR]

Published
2020
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21. Aromatase and estrogens: involvement in constitutive and regenerative neurogenesis in adult zebrafish

Author

Pellegrini, Elisabeth, Coumailleau, P, Kah, O, Diotel, Nicolas, Institut de recherche en santé, environnement et travail (Irset), Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique )-Institut National de la Santé et de la Recherche Médicale (INSERM)-École des Hautes Études en Santé Publique [EHESP] (EHESP)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Université d'Angers (UA), Groupe d'Etude sur l'Inflammation Chronique et l'Obésité (GEICO), Université de La Réunion (UR), Kelli A Duncan, Université d'Angers (UA)-Université de Rennes (UR)-École des Hautes Études en Santé Publique [EHESP] (EHESP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), and Jonchère, Laurent

Subjects
[SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, [SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate Zoology, [SDV.NEU.NB] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, [SDV.BA.ZV] Life Sciences [q-bio]/Animal biology/Vertebrate Zoology, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2015
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22. Nerve growth factor is expressed and stored in central neurons of adult zebrafish.

Author

Cacialli, Pietro, Gatta, Claudia, D'Angelo, Livia, Leggieri, Adele, Palladino, Antonio, Girolamo, Paolo, Pellegrini, Elisabeth, and Lucini, Carla

Subjects
NERVE growth factor, NEUROTROPHINS, NEURAL stem cells, NEURONS, CENTRAL nervous system, NEUROGLIA
Abstract

Nerve growth factor (NGF), a member of the neurotrophin family, was initially described as neuronal survival and growth factor, but successively has emerged as an active mediator in many essential functions in the central nervous system of mammals. NGF is synthesized as a precursor pro‐NGF and is cleaved intracellularly into mature NGF. However, recent evidence demonstrates that pro‐NGF is not a simple inactive precursor, but is also secreted outside the cells and can exert multiple roles. Despite the vast literature present in mammals, studies devoted to NGF in the brain of other vertebrate models are scarce. Zebrafish is a teleost fish widely known for developmental genetic studies and is well established as model for translational neuroscience research. Genomic organization of zebrafish and mouse NGF is highly similar, and zebrafish NGF protein has been reported in mature and two‐precursors forms. To add further knowledge on neurotrophic factors in vertebrate brain models, we decided to determine the NGF mRNA and protein distribution in the adult zebrafish brain and to characterize the phenotype of NGF‐positive cells. NGF mRNA was visualized by in situ hybridization on whole‐mount brains. NGF protein distribution was assessed on microtomic sections by using an antiserum against NGF, able to recognize pro‐NGF in adult zebrafish brain as demonstrated also in previous studies. To characterize NGF‐positive cells, anti‐NGF was employed on microtomic slides of aromatase B transgenic zebrafish (where radial glial cells appeared fluorescent) and by means of double‐immunolabeling against NGF/proliferative cell nuclear antigen (PCNA; proliferation marker) and NGF/microtube‐associated protein2 (MAP2; neuronal marker). NGF mRNA and protein were widely distributed in the brain of adult zebrafish, and their pattern of distribution of positive perikaryal was overlapping, both in males and females, with few slight differences. Specifically, the immunoreactivity to the protein was observed in fibers over the entire encephalon. MAP2 immunoreactivity was present in the majority of NGF‐positive cells, throughout the zebrafish brain. PCNA and aromatase B cells were not positive to NGF, but they were closely intermingled with NGF cells. In conclusion, our study demonstrated that mature neurons in the zebrafish brain express NGF mRNA and store pro‐NGF. [ABSTRACT FROM AUTHOR]

Published
2019
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23. Steroid Transport, Local Synthesis, and Signaling within the Brain: Roles in Neurogenesis, Neuroprotection, and Sexual Behaviors.

Author

Diotel, Nicolas, Charlier, Thierry D., Lefebvre d'Hellencourt, Christian, Couret, David, Trudeau, Vance L., Nicolau, Joel C., Meilhac, Olivier, Kah, Olivier, and Pellegrini, Elisabeth

Subjects
BRAIN tumors, ADRENOCORTICAL hormones
Abstract

Sex steroid hormones are synthesized from cholesterol and exert pleiotropic effects notably in the central nervous system. Pioneering studies from Baulieu and colleagues have suggested that steroids are also locally-synthesized in the brain. Such steroids, called neurosteroids, can rapidly modulate neuronal excitability and functions, brain plasticity, and behavior. Accumulating data obtained on a wide variety of species demonstrate that neurosteroidogenesis is an evolutionary conserved feature across fish, birds, and mammals. In this review, we will first document neurosteroidogenesis and steroid signaling for estrogens, progestagens, and androgens in the brain of teleost fish, birds, and mammals. We will next consider the effects of sex steroids in homeostatic and regenerative neurogenesis, in neuroprotection, and in sexual behaviors. In a last part, we will discuss the transport of steroids and lipoproteins from the periphery within the brain (and vice-versa) and document their effects on the blood-brain barrier (BBB) permeability and on neuroprotection. We will emphasize the potential interaction between lipoproteins and sex steroids, addressing the beneficial effects of steroids and lipoproteins, particularly HDL-cholesterol, against the breakdown of the BBB reported to occur during brain ischemic stroke. We will consequently highlight the potential anti-inflammatory, anti-oxidant, and neuroprotective properties of sex steroid and lipoproteins, these latest improving cholesterol and steroid ester transport within the brain after insults. [ABSTRACT FROM AUTHOR]

Published
2018
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24. Aromatase B radial glial progenitors: the key to brain plasticity in fish?

Author

Diotel, Nicolas, Vaillant, Colette, Pellegrini, Elisabeth, Anglade, Isabelle, Benquet, Pascal, Kah, Olivier, Interactions cellulaires et moléculaires (ICM), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and Brébion, Alice

Subjects
[SDV] Life Sciences [q-bio], [SDV]Life Sciences [q-bio]
Published
2010

25. Radial glial progenitor cells and their involvement in brain repair in adult zebrafish

Author

Diotel, Nicolas, Vaillant, Colette, Pellegrini, Elisabeth, Anglade, Isabelle, Thieulant, Marie-Lise, Kah, Olivier, Interactions cellulaires et moléculaires (ICM), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), and De Villemeur, Hervé

Subjects
[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, ComputingMethodologies_GENERAL, [SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology
Abstract

Poster

Published
2009

26. In vivo imaging and electrical characterization of dividing radial glial cells in the brain of zebrafish

Author

Benquet, Pascal, Pellegrini, Elisabeth, Diotel, Nicolas, Vaillant, Colette, Chung, B. C., Tong, S. K., Senger, Fabrice, Kah, Olivier, Interactions cellulaires et moléculaires (ICM), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Institute of Molecular Biology (IMB Sinica), Academia Sinica, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and De Villemeur, Hervé

Subjects
[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], ComputingMethodologies_GENERAL, [SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology
Abstract

Poster

Published
2009

27. Aromatase in radial glial progenitors of fish brain: evolutive novelty or conserved feature of vertebrates

Author

Kah, Olivier, Mouriec, Karen, Diotel, Nicolas, Vaillant, Colette, Le Bouc, Marie, Thieulant, Marie-Lise, Pellegrini, Elisabeth, Somoza, Gustavo, Interactions cellulaires et moléculaires (ICM), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), IIB-INTECH, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and De Villemeur, Hervé

Subjects
[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, [SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2009

28. Brain aromatase in teleost fish : expression, regulation and potential functions

Author

Kah, Olivier, Mouriec, Karen, Tong, S. K., Diotel, Nicolas, Le Page, Yann, Anglade, Isabelle, Pakdel, Farzad, Vaillant, Colette, Thieulant, Marie-Lise, Pellegrini, Elisabeth, Chung, B. C., Interactions cellulaires et moléculaires (ICM), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Institute of Molecular Biology (IMB Sinica), Academia Sinica, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and De Villemeur, Hervé

Subjects
[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, [SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2009

29. Heterogeneity of radial glial progenitor cells and their involvement in brain repair in adult zebrafish

Author

Diotel, Nicolas, Vaillant, Colette, Pellegrini, Elisabeth, Anglade, Isabelle, Thieulant, Marie-Lise, Kah, Olivier, Interactions cellulaires et moléculaires (ICM), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and De Villemeur, Hervé

Subjects
[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, ComputingMethodologies_GENERAL, [SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology
Abstract

Poster

Published
2009

30. Neuronal progenitor cells expresssing aromatase B in the brain of adult teleost: an evolutive novelty or an exaggeration of a more discrete mechanism connecting estradiol with neurogenesis?

Author

Mouriec, Karen, Pellegrini, Elisabeth, Anglade, Isabelle, Guéguen, Marie-Madeleine, Thieulant, Marie-Lise, Pakdel, Farzad, Kah, Olivier, Interactions cellulaires et moléculaires (ICM), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and De Villemeur, Hervé

Subjects
[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology
Abstract

Conférence invitée donnée par K. Mouriec; International audience

Published
2009

31. Heterogeneity of radial glial cells in the brain of zebrafish

Author

Diotel, Nicolas, Mouriec, Karen, Pellegrini, Elisabeth, Tong, S. K., Chung, B. C., Kah, Olivier, Vaillant, Colette, Interactions cellulaires et moléculaires (ICM), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Institute of Molecular Biology (IMB Sinica), Academia Sinica, De Villemeur, Hervé, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, ComputingMethodologies_GENERAL, [SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology
Abstract

Poster

Published
2008

32. Sexual dimorphism in the expression of steroidogenic enzyme genes in the brain of rainbow trout around the period of gonadal sex differentiation

Author

Vizziano, Denise, Pellegrini, Elisabeth, Mouriec, Karen, Gueguen, M.M., Anglade, Isabelle, Guiguen, Yann, Kah, Olivier, Universidad de la República, CNRS UMR6026 Interactions cellulaires et moléculaires (ICM), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Institut Fédératif de Recherche - Génétique Fonctionnelle Agronomie et Santé (IFR 140 GFAS), Plateforme Génomique Santé Biogenouest®, Station commune de Recherches en Ichtyophysiologie, Biodiversité et Environnement (SCRIBE), Institut National de la Recherche Agronomique (INRA), Supported by IFR 140, CNRS, INRA, CSIC, and the Université of Rennes 1, Interactions cellulaires et moléculaires (ICM), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-IFR140-Université de Rennes 1 (UR1), Institut National de la Recherche Agronomique (INRA)-IFR140, ProdInra, Migration, Universidad de la República [Montevideo] (UDELAR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), and De Villemeur, Hervé

Subjects
endocrine system, [SDV.BDD] Life Sciences [q-bio]/Development Biology, [SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.BDD]Life Sciences [q-bio]/Development Biology, [SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology, SALMONIDE
Abstract

National audience; The genetic and environmental factors underlying sex determination and differentiation in teleost fish are still a matter of active debate. Nevertheless, the current hypothesis is that ovarian aromatase (cyp19a) expression plays a key role in orienting the embryonic gonad towards the female phenotype. On another hand, it is now well known that the brain of teleosts has a very high aromatase activity and that brain aromatase (cyp19b) expression occurs early during development. However, the potential role of aromatase in brain sexual differentiation is totally unknown. In this study, we monitor, for the first time in teleosts, the expression of the main steroidogenic enzymes in genetic all-male and all-female populations. Brains were dissected from male and female larvae around the period of sexual differentiation between 37 and 54 days post-fertilization at 10°C. At each of these time points, samples were pooled (n=30 to 50 depending on the stage) and mRNA were extracted for real-time RT-PCR gene expression analysis of cyp19b (cytochrome P450 aromatase B), cyp11a1 (cholesterol side chain cleavage), hsd3b1 (3β-hydroxysteroiddehydrogenase), cyp17a1 (17-hydroxylase) and sf1 (nr5a1b, steroidogenic factor 1). Very interestingly, a clear sexual dimorphism was observed between males and females which, in general, showed expression levels lower than in males. This was particularly obvious in the case of cyp19b and cyp11a1, but also for cyp17a1, at least at the youngest stages. Of particular interest is the fact that measurements performed on the gonads of the same animals showed opposite results, i.e., higher gene expression of most steroidogenic enzymes in females than males. Strikingly, brain aromatase (cyp19b) expression is much higher in the brain of males than in the brain of females, whereas expression of gonadal aromatase (cyp19a) is much higher in the differentiating female gonad. These results demonstrate that, at the time of gonadal differentiation, the brain is already sexually differentiated with at least some genes encoding steroidogenic enzymes exhibiting a clear sexual dimorphism. This early brain molecular sex differentiation may actually be more pronounced as in addition to these results, we also identified using a global microarray approach some other genes with a clear sexually dimorphic expression.

Published
2007

33. Estrogenic signalling in the brain of developing zebrafish

Author

Mouriec, Karen, Anglade, Isabelle, Pellegrini, Elisabeth, Guéguen, Marie-Madeleine, Lareyre, Jean-Jacques, Pakdel, Farzad, Kah, Olivier, Interactions cellulaires et moléculaires (ICM), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Financé par le CNRS, le Ministère de la Recherche (ACI : Biologie du Développement et Physiologie Intégrative) et l'Union Européenne (EDEN)., De Villemeur, Hervé, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDV.BDD] Life Sciences [q-bio]/Development Biology, [SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.BDD]Life Sciences [q-bio]/Development Biology, [SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology, hormones, hormone substitutes, and hormone antagonists
Abstract

Poster; It is now well admitted that estrogens have important actions in the development and functioning of the central nervous system through modulation of neural differentiation and cell survival in vitro and in vivo. The classical pathways of estrogenic effects involve nuclear receptors acting as ligand-dependant transcription factors that regulate the expression of target genes either directly, by binding to an estrogen responsive element (ERE), or indirectly through interaction with others transcription factors. While only two estrogen receptors (ER), namely ERα and ERβ have been clearly characterized in mammals, birds and amphibians, two ERβ exist in teleost fish, ERβ1 and ERβ2, resulting from a duplication of the ERβ gene. We have recently shown that aromatase B (AroB, the product of the cyp19b gene) in adult zebrafish is expressed in radial glial cells and is strongly up-regulated by estradiol, an effect that involves ER and an ERE located in the proximal cyp19b promoter. Here, we studied the emergence of estrogen signalling by looking at the spatiotemporal expression of three estradiol receptors and aromatase B using in situ hybridization and quantitative real-time PCR and determining the onset of AroB upregulation by estradiol. Our results show a tissue-specific distribution and a differential spatiotemporal expression of ER mRNA with a significant induction of the expression of the three receptors between 24 and 48hpf. In situ hybridization shows that ERβ1 and ERβ2 are expressed early during development in the neuroendocrine regions, while ERα was not detected in the brain until three weeks pf. Between 24 and 48hpf, the expression of AroB mRNA also strongly increases, but this increase is partly blocked by the pure anti-estrogen ICI 182-780. This pattern suggests a concordance between expression of AroB and ER mRNAs. In accordance with these data, from 48hpf to 130hpf, AroB mRNA up-regulation induced by estradiol is abolished by ICI 182-780. Altogether, these data show that functional ERs are expressed in the brain of zebrafish at 48hpf.

Published
2007

34. Characterization of aromatase and BLBP-positive radial glial cells in the brain of adult zebrafish

Author

Diotel, Nicolas, Mouriec, Karen, Pellegrini, Elisabeth, Guéguen, Marie-Madeleine, Thieulant, Marie-Lise, Kah, Olivier, Vaillant, Colette, Interactions cellulaires et moléculaires (ICM), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Supported by ACI (Physiologie Intégrative et Biologie du Développement) and the CNRS, Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), and De Villemeur, Hervé

Subjects
[SDV.BDD] Life Sciences [q-bio]/Development Biology, [SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.BDD]Life Sciences [q-bio]/Development Biology, [SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology
Abstract

Poster; It is now widely accepted that radial glial cells play a fundamental role in the process of embryonic neurogenesis. In contrast to mammals, radial glial cells are maintained during adulthood in teleost fishes and this persistence is likely to be related to the intense neurogenic activity of the adult fish brain. We and others have recently shown that radial glial cells are progenitor cells capable of generating new neurons in adult zebrafish (Danio rerio). More precisely, we showed that aromatase B (CYP19B, AroB), the synthetic enzyme of estradiol, is strongly expressed in a subset of radial cells, essentially in the forebrain of adult males and females. We also demonstrated that many of these aromatasepositive radial cells have mitotic activity and generate neurons. The purpose of this work is to further characterize cells presenting proliferative activity by looking at other radial cells markers. Among potential markers, BLBP (Brain lipid binding protein) appeared pertinent as it is is highly expressed in the developing central nervous system of mammals and considered as a marker of radial glial cells and immature astrocytes. BLBP (Fabp7 or BFABP) is a brain specific member of the large family of hydrophobic ligand-binding protein (Fatty Acid Binding Proteins: FABPs). In the present study, we compare the expression of BLBP in radial glial cells of the zebrafish with that of AroB using immunohistochemistry. The data showed that BLBP is highly expressed in radial glial cells of the entire brain. In the regions where AroB is strongly expressed, there is a good correlation between the distribution of AroB-positive and BLBP-positive radial glial cells. Double staining for AroB and BLBP showed that most of radial glial cells of the forebrain coexpress the two markers; however, some express only one. We also performed double staining with BLBP and PCNA (Proliferating Cell Nuclear Antigen). Data showed that most BLBP-positive radial glial cells are also PCNA-positive cells, suggesting that the BLBP-positive cells are able to divide. The in vivo data presented here extend previously published data on radial glial markers in adult fish and demonstrate that BLBP is an excellent marker of radial glial cells of the zebrafish adult brain. Nevertheless, the present data suggest that heterogeneity occurs within the radial glial cell population. A more detailed study is thus needed to further characterize the phenotype of mitotically-active radial glial cells in adult fish.

Published
2007

35. Characterization of a transgenic zebrafish line expressing GFP in aromatase B-positive and BLBP positive radial glia progenitor cells

Author

Mouriec, Karen, Pellegrini, Elisabeth, Kah, Olivier, Chung, B. C., Interactions cellulaires et moléculaires (ICM), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Institute of Molecular Biology (IMB Sinica), Academia Sinica, De Villemeur, Hervé, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, ComputingMethodologies_GENERAL, [SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, [SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology
Abstract

Poster

Published
2007

36. Emergence of estrogen signalling in the brain of zebrafish embryos and larvae

Author

Anglade, Isabelle, Mouriec, Karen, Pellegrini, Elisabeth, Lethimonier, Christèle, Lareyre, Jean-Jacques, Pakdel, Farzad, Kah, Olivier, Interactions cellulaires et moléculaires (ICM), Centre National de la Recherche Scientifique (CNRS)-IFR140-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Station commune de Recherches en Ichtyophysiologie, Biodiversité et Environnement (SCRIBE), Institut National de la Recherche Agronomique (INRA)-IFR140, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA), CNRS UMR6026 Interactions cellulaires et moléculaires (ICM), ProdInra, Migration, De Villemeur, Hervé, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDV] Life Sciences [q-bio], [SDV]Life Sciences [q-bio], [SDV.BDD] Life Sciences [q-bio]/Development Biology, [INFO]Computer Science [cs], [SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], ComputingMethodologies_GENERAL, [INFO] Computer Science [cs], [SDV.BDD]Life Sciences [q-bio]/Development Biology, [SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology, ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2007

37. Aromatase B is expressed in progenitor cells in the brain of adult zebrafish

Author

Mouriec, Karen, Pellegrini, Elisabeth, Francois BRION, Anglade, Isabelle, Pakdel, Farzad, Kah, Olivier, Interactions cellulaires et moléculaires (ICM), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Institut National de l'Environnement Industriel et des Risques (INERIS), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
stomatognathic diseases, InformationSystems_MODELSANDPRINCIPLES, ComputingMilieux_THECOMPUTINGPROFESSION, GeneralLiterature_INTRODUCTORYANDSURVEY, health care facilities, manpower, and services, education, ComputingMilieux_COMPUTERSANDEDUCATION, [SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.BDD]Life Sciences [q-bio]/Development Biology, ComputingMilieux_MISCELLANEOUS, health care economics and organizations
Abstract

Brain aromatization of androgens is particularly important for the organization of sexually dimorphic structures in the brain, testosterone feedback on neuroendocrine circuits controlling the reproductive axis, and regulation of sexual behavior. The brain of teleost fish is characterized by a high aromatase activity corresponding to expression of Aromatase B (AroB) (cyp19b), one of two cyp19 duplicates. In teleost species, including the zebrafish, it was shown that Aromatase B (AroB) is expressed in radial glial cells. Given the well-known role of radial glial cells as progenitor cells during embryogenesis, we examined the possibility that Aromatase B radial cells are progenitor cells in the brain of adult fish using a combination of BrdU treatment and immunohistochemistry. We demonstrate for the first time, that aromatase-positive radial cells actively divide to generate newborn cells in many forebrain regions. These data provide new evidence for the mechanisms underlying adult neurogenesis in fish. Given that estrogens are known to affect proliferation, apoptosis, migration and differentiation, expression of Aromatase B (AroB) in progenitor cells is likely to affect adult neurogenesis under certain physiological conditions.

Published
2007

38. Aromatase is expressed in progenitor cells in the brain of adult zebrafish

Author

Mouriec, Karen, Pellegrini, Elisabeth, Brion, François, Anglade, Isabelle, Pakdel, Farzad, Kah, Olivier, Interactions Cellulaires et Moléculaires, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-IFR98-Centre National de la Recherche Scientifique (CNRS), Institut National de l'Environnement Industriel et des Risques (INERIS), Université de Rennes (UR)-IFR98-Centre National de la Recherche Scientifique (CNRS), and Civs, Gestionnaire

Subjects
[SDE] Environmental Sciences, [SDV.TOX.ECO] Life Sciences [q-bio]/Toxicology/Ecotoxicology, [SDE]Environmental Sciences, [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology
Published
2007

39. How adult fish grow their brains? A functional link between neurogenesis and aromatase activity in zebrafish

Author

Pellegrini, Elisabeth, Mouriec, Karen, Menuet, Arnaud, Anglade, Isabelle, Brion, F., Pakdel, Farzad, Kah, Olivier, Interactions cellulaires et moléculaires (ICM), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Interactions Cellulaires et Moléculaires, Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-IFR98-Centre National de la Recherche Scientifique (CNRS), Institut National de l'Environnement Industriel et des Risques (INERIS), Civs, Gestionnaire, Université de Rennes (UR)-IFR98-Centre National de la Recherche Scientifique (CNRS), De Villemeur, Hervé, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDE] Environmental Sciences, POISSON ZEBRE, [SDV.TOX.ECO] Life Sciences [q-bio]/Toxicology/Ecotoxicology, [SDE]Environmental Sciences, NEUROGENESE, AROMATASE, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology
Published
2006

40. Brain and gonadal aromatase as potential targets for endocrine disruptors in a model species, the zebrafish (Danio rerio)

Author

Hinfray, N., Pellegrini, Elisabeth, Kah, Olivier, Porcher, J., Pakdel, Farzad, Brion, F., Interactions cellulaires et moléculaires (ICM), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), and De Villemeur, Hervé

Subjects
[SDV.MHEP.EM] Life Sciences [q-bio]/Human health and pathology/Endocrinology and metabolism, [SDV.MHEP.EM]Life Sciences [q-bio]/Human health and pathology/Endocrinology and metabolism
Published
2005

41. Radial cells as a major source of estrogens in the brain of teleost fish

Author

Kah, Olivier, Pellegrini, Elisabeth, Menuet, Arnaud, Lethimonier, Christèle, Le Page, Yann, Anglade, Isabelle, Brion, François, Pakdel, Farzad, Civs, Gestionnaire, Interactions Cellulaires et Moléculaires, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-IFR98-Centre National de la Recherche Scientifique (CNRS), Institut National de l'Environnement Industriel et des Risques (INERIS), and Université de Rennes (UR)-IFR98-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDE] Environmental Sciences, [SDV.TOX.ECO] Life Sciences [q-bio]/Toxicology/Ecotoxicology, [SDE]Environmental Sciences, [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology
Published
2005

42. Brain and gonadal aromatase as potential targets for endocrine disrupting chemicals (EDCS) in a model species, the zebrafish (Danio rerio)

Author

Hinfray, Nathalie, Pellegrini, Elisabeth, Kah, Olivier, Porcher, Jean-Marc, Pakdel, Farzad, Brion, François, Civs, Gestionnaire, Institut National de l'Environnement Industriel et des Risques (INERIS), Interactions Cellulaires et Moléculaires, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-IFR98-Centre National de la Recherche Scientifique (CNRS), and Université de Rennes (UR)-IFR98-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDE] Environmental Sciences, [SDV.TOX.ECO] Life Sciences [q-bio]/Toxicology/Ecotoxicology, [SDE]Environmental Sciences, [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology
Published
2005

43. Brain and gonadal aromatase as potential targets of endocrine disrupting chemicals in a model species, the zebrafish (Danio rerio)

Author

Brion, F., Hinfray, N., Pellegrini, Elisabeth, Porcher, J., Kah, Olivier, Pakdel, Farzad, Interactions cellulaires et moléculaires (ICM), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and De Villemeur, Hervé

Subjects
[SDV.MHEP.EM] Life Sciences [q-bio]/Human health and pathology/Endocrinology and metabolism, [SDV.MHEP.EM]Life Sciences [q-bio]/Human health and pathology/Endocrinology and metabolism
Published
2005

44. Expression of brain aromatase B (CYP19B) transcript and protein in the brain and pituitary of zebrafish

Author

Pellegrini, Elisabeth, Guéguen, Marie-Madeleine, Dujardin, T., Tascon, Christophe, Menuet, Arnaud, Anglade, Isabelle, Pakdel, Farzad, Kah, Olivier, Interactions cellulaires et moléculaires (ICM), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Développement, évolution et plasticité du système nerveux (DEPSN), Centre National de la Recherche Scientifique (CNRS), Institut de Neurobiologie Alfred Fessard (INAF), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), and De Villemeur, Hervé

Subjects
[SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], ComputingMethodologies_GENERAL, [SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology
Abstract

Poster

Published
2004

45. How invisible estrogen receptors regulate brain aromatase expression in teleost fish ?

Author

Kah, Olivier, Menuet, Arnaud, Pellegrini, Elisabeth, Dujardin, T., Lann, A., Marmignon, Marie-Hélène, Kern, Laurence, Le Page, Yann, Anglade, Isabelle, Pakdel, Farzad, Interactions cellulaires et moléculaires (ICM), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), De Villemeur, Hervé, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2004

46. Expression and regulation of brain aromatase in teleost fish

Author

Kah, Olivier, Menuet, Arnaud, Pellegrini, Elisabeth, Le Guével, Rémy, Guéguen, Marie-Madeleine, Marmignon, Marie-Hélène, Anglade, Isabelle, Pakdel, Farzad, Interactions Cellulaires et Moléculaires, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-IFR98-Centre National de la Recherche Scientifique (CNRS), Développement, évolution et plasticité du système nerveux (DEPSN), Centre National de la Recherche Scientifique (CNRS), Institut de Neurobiologie Alfred Fessard (INAF), De Villemeur, Hervé, and Université de Rennes (UR)-IFR98-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology
Abstract

Conférence invitée présentée par O. Kah; International audience

Published
2003

47. Direct cooperation between estrogen receptors and astrocyte-specific factors elicits high activity of the zebrafish brain aromatase gene

Author

Menuet, Arnaud, Pellegrini, Elisabeth, Anglade, Isabelle, Le Guével, Rémy, Kah, Olivier, Pakdel, Farzad, Développement, évolution et plasticité du système nerveux (DEPSN), Centre National de la Recherche Scientifique (CNRS), Institut de Neurobiologie Alfred Fessard (INAF), Interactions Cellulaires et Moléculaires, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-IFR98-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-IFR98-Centre National de la Recherche Scientifique (CNRS), and De Villemeur, Hervé

Subjects
[SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology
Abstract

conférence invitée présentée par A. Menuet; International audience

Published
2003

48. BDNF Expression in Larval and Adult Zebrafish Brain: Distribution and Cell Identification.

Author

Cacialli, Pietro, Gueguen, Marie-Madeleine, Coumailleau, Pascal, D’Angelo, Livia, Kah, Olivier, Lucini, Carla, and Pellegrini, Elisabeth

Subjects
BRAIN-derived neurotrophic factor, ZEBRA danio, NEUROTROPHINS, DEVELOPMENTAL neurobiology, NEURONS, COGNITIVE ability, DEVELOPMENTAL genetics, PHYSIOLOGY
Abstract

Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, has emerged as an active mediator in many essential functions in the central nervous system of mammals. BDNF plays significant roles in neurogenesis, neuronal maturation and/or synaptic plasticity and is involved in cognitive functions such as learning and memory. Despite the vast literature present in mammals, studies devoted to BDNF in the brain of other animal models are scarse. Zebrafish is a teleost fish widely known for developmental genetic studies and is emerging as model for translational neuroscience research. In addition, its brain shows many sites of adult neurogenesis allowing higher regenerative properties after traumatic injuries. To add further knowledge on neurotrophic factors in vertebrate brain models, we decided to determine the distribution of bdnf mRNAs in the larval and adult zebrafish brain and to characterize the phenotype of cells expressing bdnf mRNAs by means of double staining studies. Our results showed that bdnf mRNAs were widely expressed in the brain of 7 days old larvae and throughout the whole brain of mature female and male zebrafish. In adults, bdnf mRNAs were mainly observed in the dorsal telencephalon, preoptic area, dorsal thalamus, posterior tuberculum, hypothalamus, synencephalon, optic tectum and medulla oblongata. By combining immunohistochemistry with in situ hybridization, we showed that bdnf mRNAs were never expressed by radial glial cells or proliferating cells. By contrast, bdnf transcripts were expressed in cells with neuronal phenotype in all brain regions investigated. Our results provide the first demonstration that the brain of zebrafish expresses bdnf mRNAs in neurons and open new fields of research on the role of the BDNF factor in brain mechanisms in normal and brain repairs situations. [ABSTRACT FROM AUTHOR]

Published
2016
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49. Steroid modulation of neurogenesis: Focus on radial glial cells in zebrafish.

Author

Pellegrini, Elisabeth, Diotel, Nicolas, Vaillant-Capitaine, Colette, Pérez Maria, Rita, Gueguen, Marie-Madeleine, Nasri, Ahmed, Cano Nicolau, Joel, and Kah, Olivier

Subjects
*STEROIDS, *DEVELOPMENTAL neurobiology, *NEUROGLIA, *ZEBRA danio, *STEM cells, *CELL proliferation
Abstract

Estrogens are known as steroid hormones affecting the brain in many different ways and a wealth of data now document effects on neurogenesis. Estrogens are provided by the periphery but can also be locally produced within the brain itself due to local aromatization of circulating androgens. Adult neurogenesis is described in all vertebrate species examined so far, but comparative investigations have brought to light differences between vertebrate groups. In teleost fishes, the neurogenic activity is spectacular and adult stem cells maintain their mitogenic activity in many proliferative areas within the brain. Fish are also quite unique because brain aromatase expression is limited to radial glia cells, the progenitor cells of adult fish brain. The zebrafish has emerged as an interesting vertebrate model to elucidate the cellular and molecular mechanisms of adult neurogenesis, and notably its modulation by steroids. The main objective of this review is to summarize data related to the functional link between estrogens production in the brain and neurogenesis in fish. First, we will demonstrate that the brain of zebrafish is an endogenous source of steroids and is directly targeted by local and/or peripheral steroids. Then, we will present data demonstrating the progenitor nature of radial glial cells in the brain of adult fish. Next, we will emphasize the role of estrogens in constitutive neurogenesis and its potential contribution to the regenerative neurogenesis. Finally, the negative impacts on neurogenesis of synthetic hormones used in contraceptive pills production and released in the aquatic environment will be discussed. [ABSTRACT FROM AUTHOR]

Published
2016
Full Text
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50. Inhibitory effect of cadmium on estrogen signaling in zebrafish brain and protection by zinc.

Author

Chouchene, Lina, Pellegrini, Elisabeth, Gueguen, Marie‐Madeleine, Hinfray, Nathalie, Brion, François, Piccini, Benjamin, Kah, Olivier, Saïd, Khaled, Messaoudi, Imed, and Pakdel, Farzad

Subjects
PHYSIOLOGICAL effects of cadmium, LABORATORY zebrafish, ESTROGEN receptors, GENETIC transcription, CELL communication, CADMIUM poisoning
Abstract

The present study was conducted to assess the effects of Cd exposure on estrogen signaling in the zebrafish brain, as well as the potential protective role of Zn against Cd-induced toxicity. For this purpose, the effects on transcriptional activation of the estrogen receptors (ERs), aromatase B (Aro-B) protein expression and molecular expression of related genes were examined in vivo using wild-type and transgenic zebrafish embryos. For in vitro studies, an ER-negative glial cell line (U251MG) transfected with different zebrafish ER subtypes (ERα, ERβ1 and ERβ2) was also used. Embryos were exposed either to estradiol (E2), Cd, E2+Cd or E2+Cd+Zn for 72 h and cells were exposed to the same treatments for 30 h. Our results show that E2 treatment promoted the transcriptional activation of ERs and increased Aro-B expression, at both the protein and mRNA levels. Although exposure to Cd, does not affect the studied parameters when administered alone, it significantly abolished the E2-stimulated transcriptional response of the reporter gene for the three ER subtypes in U251-MG cells, and clearly inhibited the E2 induction of Aro-B in radial glial cells of zebrafish embryos. These inhibitory effects were accompanied by a significant downregulation of the expression of esr1, esr2a, esr2b and cyp19a1b genes compared to the E2-treated group used as a positive control. Zn administration during simultaneous exposure to E2 and Cd strongly stimulated zebrafish ERs transactivation and increased Aro-B protein expression, whereas mRNA levels of the three ERs as well as the cyp19a1b remained unchanged in comparison with Cd-treated embryos. In conclusion, our results clearly demonstrate that Cd acts as a potent anti-estrogen in vivo and in vitro, and that Cd-induced E2 antagonism can be reversed, at the protein level, by Zn supplement. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Published
2016
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