title: Influence of estrogens on GH-cell network dynamics in females: a live in situ imaging approach.
abstract: The secretion of endocrine hormones from pituitary cells finely regulates a multitude of homeostatic processes. To dynamically adapt to changing physiological status and environmental stimuli, the pituitary gland must undergo marked structural and functional plasticity. Endocrine cell plasticity is thought to primarily rely on variations in cell proliferation and size. However, cell motility, a process commonly observed in a variety of tissues during development, may represent an additional mechanism to promote plasticity within the adult pituitary gland. To investigate this, we used multiphoton time-lapse imaging methods, GH-enhanced green fluorescent protein transgenic mice and sexual dimorphism of the GH axis as a model of divergent tissue demand. Using these methods to acutely (12 h) track cell dynamics, we report that ovariectomy induces a dramatic and dynamic increase in cell motility, which is associated with gross GH-cell network remodeling. These changes can be prevented by estradiol supplementation and are associated with enhanced network connectivity as evidenced by increased coordinated GH-cell activity during multicellular calcium recordings. Furthermore, cell motility appears to be sex-specific, because reciprocal alterations are not detected in males after castration. Therefore, GH-cell motility appears to play an important role in the structural and functional pituitary plasticity, which is evoked in response to changing estradiol concentrations in the female.
authors.affiliation: Centre National de la Recherche Scientifique, Institute of Functional Genomics, Institut National de la Santé et de la Recherche Médicale, Universities of Montpellier 1 and 2, UMR-5203, F-34000 Montpellier, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Schaeffer
authors.forename: David J
authors.initials: DJ
authors.lastname: Hodson
authors.forename: Anne-Cécile
authors.initials: AC
authors.lastname: Meunier
authors.forename: Chrystel
authors.initials: C
authors.lastname: Lafont
authors.forename: Jérôme
authors.initials: J
authors.lastname: Birkenstock
authors.forename: Danielle
authors.initials: D
authors.lastname: Carmignac
authors.forename: Joanne F
authors.initials: JF
authors.lastname: Murray
authors.forename: Elodie
authors.initials: E
authors.lastname: Gavois
authors.forename: Iain C
authors.initials: IC
authors.lastname: Robinson
authors.forename: Paul
authors.initials: P
authors.lastname: Le Tissier
authors.forename: Patrice
authors.initials: P
authors.lastname: Mollard
mesh_terms: D000818:Animals; D002465:Cell Movement; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D049452:Green Fluorescent Proteins; D013006:Growth Hormone / Q000032:analysis*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D010902:Pituitary Gland / Q000166:cytology*; D012737:Sex Factors; D059008:Time-Lapse Imaging
chemical_list: D004967:Estrogens; D049452:Green Fluorescent Proteins; D013006:Growth Hormone