title: VEGF signalling controls GnRH neuron survival via NRP1 independently of KDR and blood vessels.
abstract: Gonadotropin-releasing hormone (GnRH) neurons are neuroendocrine cells that are born in the nasal placode during embryonic development and migrate through the nose and forebrain to the hypothalamus, where they regulate reproduction. Many molecular pathways that guide their migration have been identified, but little is known about the factors that control the survival of the migrating GnRH neurons as they negotiate different environments. We previously reported that the class 3 semaphorin SEMA3A signals through its neuropilin receptors, NRP1 and NRP2, to organise the axons that guide migrating GnRH neurons from their birthplace into the brain. By combining analysis of genetically altered mice with in vitro models, we show here that the alternative neuropilin ligand VEGF164 promotes the survival of migrating GnRH neurons by co-activating the ERK and AKT signalling pathways through NRP1. We also demonstrate that survival signalling relies on neuronal, but not endothelial, NRP1 expression and that it occurs independently of KDR, the main VEGF receptor in blood vessels. Therefore, VEGF164 provides survival signals directly to developing GnRH neurons, independently of its role in blood vessels. Finally, we show that the VEGF164-mediated neuronal survival and SEMA3A-mediated axon guidance cooperate to ensure that migrating GnRH neurons reach the brain. Thus, the loss of both neuropilin ligands leads to an almost complete failure to establish the GnRH neuron system.
authors.affiliation: Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK.
authors.forename: Anna
authors.initials: A
authors.lastname: Cariboni
authors.forename: Kathryn
authors.initials: K
authors.lastname: Davidson
authors.forename: Elena
authors.initials: E
authors.lastname: Dozio
authors.forename: Fani
authors.initials: F
authors.lastname: Memi
authors.forename: Quenten
authors.initials: Q
authors.lastname: Schwarz
authors.forename: Fabio
authors.initials: F
authors.lastname: Stossi
authors.forename: John G
authors.initials: JG
authors.lastname: Parnavelas
authors.forename: Christiana
authors.initials: C
authors.lastname: Ruhrberg
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism; D001808:Blood Vessels / Q000378:metabolism*; D049109:Cell Proliferation; D002470:Cell Survival / Q000235:genetics / Q000502:physiology*; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009474:Neurons / Q000166:cytology* / Q000378:metabolism*; D039942:Neuropilin-1 / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics / Q000378:metabolism*; D042442:Vascular Endothelial Growth Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D042442:Vascular Endothelial Growth Factors; D039942:Neuropilin-1; D007987:Gonadotropin-Releasing Hormone; D040301:Vascular Endothelial Growth Factor Receptor-2