Synergistic cooperation between hypoxia and transforming growth factor-beta pathways on human vascular endothelial growth factor gene expression.
Signaling by transforming growth factor (TGF)-beta family members is mediated by Smad proteins that regulate gene transcription through functional cooperativity and association with other DNA-binding proteins. The hypoxia-inducible factor (HIF)-1 is a transcriptional complex that plays a key role in oxygen-regulated gene expression. We demonstrate that hypoxia and TGF-beta cooperate in the induction of the promoter activity of vascular endothelial growth factor (VEGF), which is a major stimulus in the promotion of angiogenesis. This cooperation has been mapped on the human VEGF promoter within a region at -1006 to -954 that contains functional DNA-binding sequences for HIF-1 and Smads. Optimal HIF-1alpha-dependent induction of the VEGF promoter was obtained in the presence of Smad3, suggesting an interaction between these proteins. Consistent with this, co-immunoprecipitation experiments revealed that HIF-1alpha physically associates with Smad3. These results demonstrate that both TGF-beta and hypoxia signaling pathways can synergize in the regulation of VEGF gene expression at the transcriptional level.
Sánchez-Elsner
T
T
Centro de Investigaciones Biológicas, CSIC, Velázquez 144, 28006 Madrid, Spain.
Botella
L M
LM
Velasco
B
B
Corbí
A
A
Attisano
L
L
Bernabéu
C
C
D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D019556:COS Cells; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism; D016228:Endothelial Growth Factors / Q000096:biosynthesis* / Q000235:genetics*; D004797:Enzyme-Linked Immunosorbent Assay; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D000860:Hypoxia; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D008222:Lymphokines / Q000096:biosynthesis* / Q000235:genetics*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D018919:Neovascularization, Physiologic; D009687:Nuclear Proteins / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D051381:Rats; D015398:Signal Transduction; D051900:Smad3 Protein; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors; D014158:Transcription, Genetic; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D004268:DNA-Binding Proteins; D016228:Endothelial Growth Factors; C497442:HIF1A protein, human; C497444:Hif1a protein, rat; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D008222:Lymphokines; D009687:Nuclear Proteins; C497790:SMAD3 protein, human; D051900:Smad3 Protein; C497787:Smad3 protein, rat; D015534:Trans-Activators; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D010100:Oxygen