Platelet-derived growth factor (PDGF) and PDGF receptor expression and function in folliculostellate pituitary cells.

摘要: Homo- and heterodimers of platelet-derived growth factor-A (PDGF-A) PDGF-B chains are involved through PDGF alpha- beta-receptors in the regulation multiple normal tumoural cell types as well tumour neovascularization. Since little information is available on impact PDGF/PDGF receptors adenomatous pituitary, we studied expression action this factor system a variety pituitary lines rat anterior cultures. By RT-PCR, mRNA PDGF-A -B both was found mouse folliculostellate TtT/GF cells. Rat somatotroph MtT-S corticotroph AtT20 tumor cells expressed only part receptor components whereas gonadotroph alphaT3-1 lactosomatotroph GH3 contained neither nor receptors. To further characterize role cells, effect PDGF-AB -BB vascular endothelial (VEGF-A) release studied. Proliferation weakly but significantly stimulated by PDGF. Both cultures strongly enhanced VEGF-A secretion. The PI3 kinase inhibitor LY 294002 blocked increase VEGF-A. Western immunoblotting confirmed participation key kinase/Akt signal pathway (PDK1, Akt-Ser476) PDGF-stimulated VEGF production. Thus regulation. Its endocrine adenomas need to be clarified future studies.