Ganglioside effects on basic fibroblast and epidermal growth factor receptors in retinal glial cells.
Gangliosides have long been implicated in cell growth regulation and play an important role as modulators in protein phosphorylation. In order to better understand how glycosphingolipids and growth factors interact, we examined the modulation of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) effects on retinal Müller glial cells (RMG), following modification of their GG composition. Treatment of MG cells with GG (GM1, GT1b) and asialoGM1 resulted in modifications of several aspects of cellular responses to EGF- and FGF-receptor (R) activation: mitogenesis, cell migration, tyrosine phosphorylation of the EGF-R and FGF-R and even their cellular substrates were particularly influenced by GG. Indeed GG caused modifications of EGF-R and FGF-R autophosphorylation kinetics. GG long term effects (mitogenesis and migration) correlate with short term effects (tyrosine phosphorylation) and differences in receptor tyrosine kinase signalling could explain the specificity in growth factor responses.
INSERM U. 338, Centre de Neurochimie, Strasbourg, France.
E
E
Meuillet
G
G
Crémel
D
D
Hicks
H
H
Dreyfus
D000818:Animals; D002478:Cells, Cultured; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism*; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism*; D005732:Gangliosides / Q000494:pharmacology*; D051381:Rats; D017468:Receptors, Fibroblast Growth Factor / Q000378:metabolism*; D012165:Retinal Ganglion Cells / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*
D005732:Gangliosides; D017468:Receptors, Fibroblast Growth Factor; D016222:Fibroblast Growth Factor 2; D004815:Epidermal Growth Factor; D066246:ErbB Receptors