Functional expression of CXCR4 in somatotrophs: CXCL12 activates GH gene, GH production and secretion, and cellular proliferation.

摘要: The interaction of chemokine (C-X-C motif) ligand 12 (CXCL12) and its receptor CXCR4 may play an important role in the regulation anterior pituitary function. In this study, we investigated expression CXCL12 their normal rat GH-producing GH3 tumor cell line. RT-PCR analysis immunohistochemistry revealed that was expressed cells. Double immunofluorescent staining showed complete colocalization with GH pituitary, indicating is specifically somatotrophs. Using primary cultures releasing hormone expressing stable cells (GH3-GHRHR), evaluated function compared GHRH. stimulated gene activation both GH3-GHRHR also secretion from a dose-dependant manner. BrdU incorporation increased response to addition culture, CXCL12-induced proliferation. CXCL12-dependent phosphorylation ERK1/2 confirmed by western blot analysis, supporting evidence MAPK intracellular mediator CXCL12/CXCR4 conclusion, these results indicate plays production, secretion, proliferation