title: Characterization of Gonadotrope Secretoproteome Identifies Neurosecretory Protein VGF-derived Peptide Suppression of Follicle-stimulating Hormone Gene Expression.
abstract: Reproductive function is controlled by the pulsatile release of hypothalamic gonadotropin-releasing hormone (GnRH), which regulates the expression of the gonadotropins luteinizing hormone and FSH in pituitary gonadotropes. Paradoxically, Fshb gene expression is maximally induced at lower frequency GnRH pulses, which provide a very low average concentration of GnRH stimulation. We studied the role of secreted factors in modulating gonadotropin gene expression. Inhibition of secretion specifically disrupted gonadotropin subunit gene regulation but left early gene induction intact. We characterized the gonadotrope secretoproteome and global mRNA expression at baseline and after Gαsknockdown, which has been found to increase Fshb gene expression (1). We identified 1077 secreted proteins or peptides, 19 of which showed mRNA regulation by GnRH or/and Gαsknockdown. Among several novel secreted factors implicated in Fshb gene regulation, we focused on the neurosecretory protein VGF. Vgf mRNA, whose gene has been implicated in fertility (2), exhibited high induction by GnRH and depended on GαsIn contrast with Fshb induction, Vgf induction occurred preferentially at high GnRH pulse frequency. We hypothesized that a VGF-derived peptide might regulate Fshb gene induction. siRNA knockdown or extracellular immunoneutralization of VGF augmented Fshb mRNA induction by GnRH. GnRH stimulated the secretion of the VGF-derived peptide NERP1. NERP1 caused a concentration-dependent decrease in Fshb gene induction. These findings implicate a VGF-derived peptide in selective regulation of the Fshb gene. Our results support the concept that signaling specificity from the cell membrane GnRH receptor to the nuclear Fshb gene involves integration of intracellular signaling and exosignaling regulatory motifs.
authors.affiliation: From the Departments of Neurology and.
authors.forename: Soon Gang
authors.identifier: http://orcid.org/0000-0003-0314-3958
authors.initials: SG
authors.lastname: Choi
authors.affiliation: From the Departments of Neurology and.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: From the Departments of Neurology and.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Jia
authors.affiliation: From the Departments of Neurology and.
authors.forename: Maria
authors.initials: M
authors.lastname: Chikina
authors.affiliation: From the Departments of Neurology and.
authors.forename: Hanna
authors.initials: H
authors.lastname: Pincas
authors.affiliation: Genetics and Genomic Sciences.
authors.forename: Georgia
authors.initials: G
authors.lastname: Dolios
authors.affiliation: Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center Research Institute, Osaka 565-8565, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Sasaki
authors.affiliation: Genetics and Genomic Sciences.
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
authors.affiliation: Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center Research Institute, Osaka 565-8565, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Minamino
authors.affiliation: Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029 and.
authors.forename: Stephen R J
authors.identifier: http://orcid.org/0000-0003-4087-8427
authors.initials: SR
authors.lastname: Salton
authors.affiliation: From the Departments of Neurology and Center for Advanced Research on Diagnostic Assays, and stuart.sealfon@mssm.edu.
authors.forename: Stuart C
authors.initials: SC
authors.lastname: Sealfon
mesh_terms: D000818:Animals; D002460:Cell Line; D005640:Follicle Stimulating Hormone / Q000096:biosynthesis*; D005786:Gene Expression Regulation / Q000502:physiology*; D052681:Gonadotrophs / Q000166:cytology / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D051379:Mice; D009414:Nerve Growth Factors; D009479:Neuropeptides / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D009414:Nerve Growth Factors; D009479:Neuropeptides; D010455:Peptides; D012333:RNA, Messenger; C512697:Vgf protein, mouse; D007987:Gonadotropin-Releasing Hormone; D005640:Follicle Stimulating Hormone
keywords: G protein; G protein-coupled receptor (GPCR); GnRH; LβT2 cells; VGF; follicle-stimulating hormone (FSH); gene regulation; gonadotrope; secretion; secretoproteome