[Control of the intracellular signaling induced by fibroblast growth factors (FGF) over the proliferation and survival of retinal pigment epithelium cells: example of the signaling regulation of growth factors endogenous to the retina ].
Retinal pigmented epithelium (RPE) cells are of central importance in the maintenance of neural retinal function. RPE cell apoptosis is responsible for the development of a variety of retinal degeneration. The role of FGF2 was investigated on RPE cell proliferation and apoptosis in vitro. In the absence of serum, RPE cells died by apoptosis, while the addition of FGF2 greatly reduces apoptosis over a 7-day culture period. This is due to an autocrine loop involving secretion of endogenous FGF1 in the mechanism that govern FGF2-induced resistance to apoptosis. FGF2 induces long-term activation of FGFR1 and ERK1/2, and production of the anti-apoptotic protein BcL-x. Because FGF1 has no classical signal sequence to direct its secretion, we investigated the effects of FGF1 secretion on RPE proliferation and apoptosis in the absence of exogenous FGF2. Forced secretion of endogenous FGF1 by adding a signal peptide to the FGF1 molecule induces FGF1 secretion and cell proliferation in the presence of serum, while in FGF1 stops to be secreted and cell die in the absence of serum. Conversely, in cells cultured in the presence of serum, FGF1 without signal peptide is not secreted, but is secreted and rescue RPE cell from apoptosis when cells are cultured without serum. Thus, the proliferation and survival activities of endogenous FGF1 depend on the secretion of FGF1 which is determined by the cell environment.
Mascarelli
F
F
INSERM U450, Développement, vieillissement et pathologie de la rétine, Affiliée CNRS, Association Claude Bernard: 29, rue Wilhem, 75016 Paris.
Hecquet
C
C
Guillonneau
X
X
Courtois
Y
Y
D000328:Adult; D017209:Apoptosis / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured / Q000187:drug effects; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D005136:Eye Proteins / Q000502:physiology*; D016220:Fibroblast Growth Factor 1 / Q000737:chemistry / Q000378:metabolism*; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects* / Q000502:physiology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000187:drug effects*; D021382:Protein Sorting Signals / Q000502:physiology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics; D051496:Receptor, Fibroblast Growth Factor, Type 1; D017468:Receptors, Fibroblast Growth Factor / Q000096:biosynthesis / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D012162:Retinal Degeneration / Q000503:physiopathology; D051020:bcl-X Protein
C494811:BCL2L1 protein, human; D016895:Culture Media, Serum-Free; D005136:Eye Proteins; D021382:Protein Sorting Signals; D019253:Proto-Oncogene Proteins c-bcl-2; D017468:Receptors, Fibroblast Growth Factor; D051020:bcl-X Protein; D016222:Fibroblast Growth Factor 2; D016220:Fibroblast Growth Factor 1; C496348:FGFR1 protein, human; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases