COUP-TFI (chicken ovalbumin upstream promoter-transcription factor I) regulates cell migration and axogenesis in differentiating P19 embryonal carcinoma cells.
The developmental expression patterns of the nuclear orphan receptors COUP-TFs (chicken ovalbumin upstream promoter-transcription factors) have been correlated to neurogenesis in several animal species. Nevertheless, the role of COUP-TFs in neurogenesis remains unknown. We have studied the functional involvement of COUP-TFI in retinoic acid (RA)-induced neuronal differentiation of P19 embryonal carcinoma cells through two complementary approaches: 1) deregulated expression of COUP-TFI, and 2) inactivation of endogenous COUP-TFs by means of a dominant-negative COUP-TFI mutant. Low levels of wild-type (wt)COUP-TFI transgene expression did not inhibit neural cell fate and primarily enhanced neuron outgrowth from RA-treated P19 aggregates. In contrast, high COUP-TFI expression impeded the neuronal differentiation of P19 cells induced with RA, resulting in cell cultures lacking neurons. This morphological effect was correlated to an elevated level of E-cadherin mRNA. The dominant-negative COUP-TFI mutant induced cell packing after RA treatment and inhibited neurite extension and neuron outgrowth from aggregates. A RGD peptide interference assay indicated that endogenous COUP-TFs could favor migration of neurons through an integrin-dependent mechanism. Accordingly, vitronectin mRNA levels were shown to be up-regulated by COUP-TFI by RT-PCR analysis, and COUP-TFI stimulated the mouse vitronectin promoter activity in transient transfection assays. Taken together, these data indicate that COUP-TFI is not simply a global repressor of retinoid functions, but shows a high selectivity for regulating genes involved in cellular adhesion and migration processes that are particularly important for neuronal differentiation.
Adam
F
F
Equipe d'Endocrinologie Moléculaire de la Reproduction, UPRES-A CNRS 6026, Université de Rennes I, France.
Sourisseau
T
T
Métivier
R
R
Le Page
Y
Y
Desbois
C
C
Michel
D
D
Salbert
G
G
D000818:Animals; D001369:Axons / Q000648:ultrastructure; D001483:Base Sequence; D051838:COUP Transcription Factor I; D018236:Carcinoma, Embryonal; D002448:Cell Adhesion; D002454:Cell Differentiation / Q000187:drug effects; D002465:Cell Movement; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D017354:Point Mutation; D011401:Promoter Regions, Genetic; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D015533:Transcriptional Activation; D014162:Transfection; D014212:Tretinoin / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D019096:Vitronectin / Q000235:genetics / Q000378:metabolism
D051838:COUP Transcription Factor I; D004268:DNA-Binding Proteins; D016326:Extracellular Matrix Proteins; C497589:NR2F1 protein, human; C497590:Nr2f1 protein, mouse; D014157:Transcription Factors; D019096:Vitronectin; D014212:Tretinoin