Growth Hormone Receptor Deletion Reduces the Density of Axonal Projections from Hypothalamic Arcuate Nucleus Neurons

Frederick Wasinski, Isadora C Furigo, Pryscila D S Teixeira, Angela M Ramos-Lobo, Cibele N Peroni, Paolo Bartolini, Edward O List, John J Kopchick, Jose Donato

Research output: Contribution to journalArticlepeer-review

26 Citations (Scopus)

Abstract

The arcuate nucleus (ARH) is an important hypothalamic area for the homeostatic control of feeding and other metabolic functions. In the ARH, proopiomelanocortin- (POMC) and agouti-related peptide (AgRP)-expressing neurons play a key role in the central regulation of metabolism. These neurons are influenced by circulating factors, such as leptin and growth hormone (GH). The objective of the present study was to determine whether a direct action of GH on ARH neurons regulates the density of POMC and AgRP axonal projections to major postsynaptic targets. We studied POMC and AgRP axonal projections to the hypothalamic paraventricular (PVH), lateral (LHA) and dorsomedial (DMH) nuclei in leptin receptor (LepR)-deficient mice (Leprdb/db), GH-deficient mice (Ghrhrlit/lit) and in mice carrying specific ablations of GH receptor (GHR) either in LepR- or AgRP-expressing cells. Leprdb/db mice presented reduction in the density of POMC innervation to the PVH compared to wild-type and Ghrhrlit/lit mice. Additionally, both Leprdb/db and Ghrhrlit/lit mice showed reduced AgRP fiber density in the PVH, LHA and DMH. LepR GHR knockout mice showed decreased density of POMC innervation in the PVH and DMH, compared to control mice, whereas a reduction in the density of AgRP innervation was observed in all areas analyzed. Conversely, AgRP-specific ablation of GHR led to a significant reduction in AgRP projections to the PVH, LHA and DMH, without affecting POMC innervation. Our findings indicate that GH has direct trophic effects on the formation of POMC and AgRP axonal projections and provide additional evidence that GH regulates hypothalamic neurocircuits controlling energy homeostasis.

Original languageEnglish
Pages (from-to)136-147
Number of pages12
JournalNeuroscience
Volume434
Early online date27 Mar 2020
DOIs
Publication statusPublished - 10 May 2020
Externally publishedYes

Bibliographical note

Copyright © 2020 IBRO. Published by Elsevier Ltd. All rights reserved.

Keywords

  • AgRP
  • development
  • food intake
  • GH
  • melanocortin system
  • POMC

Fingerprint

Dive into the research topics of 'Growth Hormone Receptor Deletion Reduces the Density of Axonal Projections from Hypothalamic Arcuate Nucleus Neurons'. Together they form a unique fingerprint.

Cite this