Ghislaine Garrel1, Chantal Denoyelle1, David L'Hôte1, Jean-Yves Picard1, Jose Teixeira2, Ursula B Kaiser3, Jean-Noël Laverrière1, Joëlle Cohen-Tannoudji4. 1. Physiologie de l'axe gonadotrope U1133, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Biologie Fonctionnelle et Adaptative UMR 8251, Sorbonne Paris Cité, Université Paris-Diderot, Paris, France. 2. Department of Obstetrics, Gynecology, and Reproductive Biology, Michigan State University, Grand Rapids, Michigan, USA. 3. Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA. 4. Physiologie de l'axe gonadotrope U1133, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Biologie Fonctionnelle et Adaptative UMR 8251, Sorbonne Paris Cité, Université Paris-Diderot, Paris, Francejoelle.cohen-tannoudji@univ-paris-diderot.fr.
Abstract
BACKGROUND/ OBJECTIVES: Anti-Müllerian hormone (AMH) signaling is critical for sexual differentiation and gonadal function. AMH receptor type 2 (AMHR2) is expressed in extragonadal sites such as brain, and pituitary and emerging evidence indicates that AMH biological action is much broader than initially thought. We recently reported that AMH signaling enhances follicle-stimulating hormone synthesis in pituitary gonadotrope cells. However, mechanisms regulating AMHR2 expression in these extragonadal sites remain to be explored. METHOD/ RESULTS: Here, we demonstrated in perifused murine LβT2 gonadotrope cells that Amhr2 expression is differentially regulated by GnRH pulse frequency with an induction under high GnRH pulsatility. Furthermore, we showed that GnRH transactivates the human AMHR2 promoter in LβT2 cells. Successive deletions of the promoter revealed the importance of a short proximal region (-53/-37 bp) containing an Egr1 binding site. Using site-directed mutagenesis of Egr1 motif and siRNA mediated-knockdown of Egr1, we demonstrated that Egr1 mediates basal and GnRH-dependent activity of the promoter, identifying Egr1 as a new transcription factor controlling hAMHR2 expression. We also showed that SF1 and β-catenin are required for basal promoter activity and demonstrated that both factors contribute to the GnRH stimulatory effect, independently of their respective binding sites. Furthermore, using a constitutively active mutant of FOXO1, we identified FOXO1 as a negative regulator of basal and GnRH-dependent AMHR2 expression in gonadotrope cells. CONCLUSIONS: This study identifies GnRH as a regulator of human AMHR2 expression, further highlighting the importance of AMH signaling in the regulation of gonadotrope function.
BACKGROUND/ OBJECTIVES: Anti-Müllerian hormone (AMH) signaling is critical for sexual differentiation and gonadal function. AMH receptor type 2 (AMHR2) is expressed in extragonadal sites such as brain, and pituitary and emerging evidence indicates that AMH biological action is much broader than initially thought. We recently reported that AMH signaling enhances follicle-stimulating hormone synthesis in pituitary gonadotrope cells. However, mechanisms regulating AMHR2 expression in these extragonadal sites remain to be explored. METHOD/ RESULTS: Here, we demonstrated in perifused murine LβT2 gonadotrope cells that Amhr2 expression is differentially regulated by GnRH pulse frequency with an induction under high GnRH pulsatility. Furthermore, we showed that GnRH transactivates the humanAMHR2 promoter in LβT2 cells. Successive deletions of the promoter revealed the importance of a short proximal region (-53/-37 bp) containing an Egr1 binding site. Using site-directed mutagenesis of Egr1 motif and siRNA mediated-knockdown of Egr1, we demonstrated that Egr1 mediates basal and GnRH-dependent activity of the promoter, identifying Egr1 as a new transcription factor controlling hAMHR2 expression. We also showed that SF1 and β-catenin are required for basal promoter activity and demonstrated that both factors contribute to the GnRH stimulatory effect, independently of their respective binding sites. Furthermore, using a constitutively active mutant of FOXO1, we identified FOXO1 as a negative regulator of basal and GnRH-dependent AMHR2 expression in gonadotrope cells. CONCLUSIONS: This study identifies GnRH as a regulator of humanAMHR2 expression, further highlighting the importance of AMH signaling in the regulation of gonadotrope function.
Authors: Samuel Andrew Malone; Georgios E Papadakis; Andrea Messina; Nour El Houda Mimouni; Sara Trova; Monica Imbernon; Cecile Allet; Irene Cimino; James Acierno; Daniele Cassatella; Cheng Xu; Richard Quinton; Gabor Szinnai; Pascal Pigny; Lur Alonso-Cotchico; Laura Masgrau; Jean-Didier Maréchal; Vincent Prevot; Nelly Pitteloud; Paolo Giacobini Journal: Elife Date: 2019-07-10 Impact factor: 8.140
Authors: Rossella Cannarella; Alyssa J J Paganoni; Stefania Cicolari; Roberto Oleari; Rosita A Condorelli; Sandro La Vignera; Anna Cariboni; Aldo E Calogero; Paolo Magni Journal: Int J Mol Sci Date: 2021-02-28 Impact factor: 5.923