Semaphorin7A regulates neuroglial plasticity in the adult hypothalamic median eminence

Jyoti Parkash, Andrea Messina, Fanny Langlet, Irene Cimino, Anne Loyens, Danièle Mazur, Sarah Gallet, Eglantine Balland, Samuel A. Malone, François Pralong, Gabriella Cagnoni, Roberta Schellino, Silvia De Marchis, Massimiliano Mazzone, R. Jeroen Pasterkamp, Luca Tamagnone, Vincent Prevot, Paolo Giacobini

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58 Citations (Scopus)

Abstract

Reproductive competence in mammals depends on the projection of gonadotropin-releasing hormone (GnRH) neurons to the hypothalamic median eminence (ME) and the timely release of GnRH into the hypothalamic-pituitary-gonadal axis. In adult rodents, GnRH neurons and the specialized glial cells named tanycytes periodically undergo cytoskeletal plasticity. However, the mechanisms that regulate this plasticity are still largely unknown. We demonstrate that Semaphorin7A, expressed by tanycytes, plays a dual role, inducing the retraction of GnRH terminals and promoting their ensheathment by tanycytic end feet via the receptors PlexinC1 and Itgb1, respectively. Moreover, Semaphorin7A expression is regulated during the oestrous cycle by the fluctuating levels of gonadal steroids. Genetic invalidation of Semaphorin7A receptors in mice induces neuronal and glial rearrangements in the ME and abolishes normal oestrous cyclicity and fertility. These results show a role for Semaphorin7A signalling in mediating periodic neuroglial remodelling in the adult ME during the ovarian cycle.

Original languageEnglish
Article number6385
Number of pages17
JournalNature Communications
Volume6
DOIs
Publication statusPublished - 27 Feb 2015
Externally publishedYes

Keywords

  • embryogenesis
  • glial biology
  • hypothalamus
  • synaptic plasticity

Cite this

Parkash, J., Messina, A., Langlet, F., Cimino, I., Loyens, A., Mazur, D., Gallet, S., Balland, E., Malone, S. A., Pralong, F., Cagnoni, G., Schellino, R., De Marchis, S., Mazzone, M., Pasterkamp, R. J., Tamagnone, L., Prevot, V., & Giacobini, P. (2015). Semaphorin7A regulates neuroglial plasticity in the adult hypothalamic median eminence. Nature Communications, 6, [6385]. https://doi.org/10.1038/ncomms7385