title: Intracellular signaling by growth hormone variant (GH-V).
abstract: Placental growth hormone, or growth hormone variant (GH-V), is a member of the growth hormone gene family. Its physiologic role during pregnancy remains undefined. Although extensive work has been done characterizing the signaling pathways activated by hGH, the signaling pathways which are activated by GH-V have not been characterized. We investigated cellular signaling by GH-V in model systems in which signaling by hGH has been well characterized. GH-V activates the STAT5b transcription factor in the IM-9 human lymphocyte and 3T3-F442A preadipocyte cell lines, and in primary porcine smooth muscle cells, which all homologously express GH receptors. In contrast, hCS does not activate signaling in these GH receptor-expressing cells. Like hGH, signaling by GH-V is inhibited by the GH antagonist (G120K). These results provide preliminary evidence that GH-V plays a major role in affecting target cells expressing the GH receptor, thus potentially exerting significant GH-like effects on maternal physiology during pregnancy.
authors.affiliation: Department of Medicine, Division of Endocrinology, University of Virginia Health System, Charlottesville, VA 22908, USA.
authors.forename: Corinne M
authors.initials: CM
authors.lastname: Silva
authors.forename: Michael T
authors.initials: MT
authors.lastname: Kloth
authors.forename: Charles E
authors.initials: CE
authors.lastname: Lyons
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Dunn
authors.forename: Susan E
authors.initials: SE
authors.lastname: Kirk
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism; D005260:Female; D013006:Growth Hormone / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008894:Milk Proteins; D010920:Placenta / Q000378:metabolism; D010926:Placental Hormones / Q000235:genetics / Q000378:metabolism*; D010928:Placental Lactogen / Q000378:metabolism; D011247:Pregnancy; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D050799:STAT5 Transcription Factor; D015398:Signal Transduction; D013552:Swine; D015534:Trans-Activators / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; C064980:GH2 protein, human; D008894:Milk Proteins; D010926:Placental Hormones; D011994:Recombinant Proteins; D050799:STAT5 Transcription Factor; C494095:STAT5B protein, human; C494096:Stat5b protein, mouse; D015534:Trans-Activators; D013006:Growth Hormone; D010928:Placental Lactogen