ESE-1 is a novel transcriptional mediator of angiopoietin-1 expression in the setting of inflammation.
Angiogenesis is a critical component of the inflammatory response associated with a number of conditions. Angiopoietin-1 (Ang-1) is an angiogenic growth factor that promotes the chemotaxis of endothelial cells and facilitates the maturation of new blood vessels. Ang-1 expression is up-regulated in response to tumor necrosis factor-alpha (TNF-alpha). To begin to elucidate the underlying molecular mechanisms by which Ang-1 gene expression is regulated during inflammation, we isolated 3.2 kb of the Ang-1 promoter that contain regulatory elements sufficient to mediate induction of the promoter in response to TNF-alpha, interleukin-1beta, and endotoxin. Surprisingly, sequence analysis of this promoter failed to reveal binding sites for transcription factors that are frequently associated with mediating inflammatory responses, such as NF-kappaB, STAT, NFAT, or C/EBP. However, putative binding sites for ETS and AP-1 transcription factor family members were identified. Interestingly, among a panel of ETS factors tested in a transient transfection assay, only the ETS factor ESE-1 was capable of transactivating the Ang-1 promoter. ESE-1 binds to specific ETS sites within the Ang-1 promoter that are functionally important for transactivation by ESE-1. ESE-1 and Ang-1 are induced in synovial fibroblasts in response to inflammatory cytokines, with ESE-1 induction slightly preceding that of Ang-1. Mutation of a high-affinity ESE-1 binding site leads to a marked reduction in Ang-1 transactivation by ESE-1, inducibility by inflammatory cytokines, and DNA binding to the ESE-1 protein. Transcriptional profiling of cells transiently transfected with an ESE-1 expression vector demonstrates that the endogenous Ang-1 gene is directly inducible by ESE-1. Finally, Ang-1 and ESE-1 exhibit a similar and strong expression pattern in the synovium of patients with rheumatoid arthritis. Our results support a novel paradigm for the ETS factor ESE-1 as a transcriptional mediator of angiogenesis in the setting of inflammation.
Brown
Courtney
C
Beth Israel Deaconess Medical Center, Department of Medicine, New England Baptist Bone and Joint Institute, Harvard Institutes of Medicine, 4 Blackfan Circle, Boston, MA 02115, USA.
Gaspar
John
J
Pettit
Allison
A
Lee
Rebecca
R
Gu
Xuesong
X
Wang
Hong
H
Manning
Cathy
C
Voland
Carole
C
Goldring
Steven R
SR
Goldring
Mary B
MB
Libermann
Towia A
TA
Gravallese
Ellen M
EM
Oettgen
Peter
P
D042683:Angiopoietin-1 / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001172:Arthritis, Rheumatoid / Q000378:metabolism; D001665:Binding Sites; D015153:Blotting, Western; D002460:Cell Line; D045744:Cell Line, Tumor; D002633:Chemotaxis; D016207:Cytokines / Q000378:metabolism; D004247:DNA / Q000737:chemistry; D004252:DNA Mutational Analysis; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism* / Q000502:physiology*; D005347:Fibroblasts / Q000378:metabolism; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D005822:Genetic Vectors; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation / Q000378:metabolism*; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D041681:NIH 3T3 Cells; D020411:Oligonucleotide Array Sequence Analysis; D009841:Oligonucleotides / Q000737:chemistry; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011518:Proto-Oncogene Proteins / Q000378:metabolism* / Q000502:physiology*; D050783:Proto-Oncogene Proteins c-ets; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism* / Q000502:physiology*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation
D042683:Angiopoietin-1; D016207:Cytokines; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C105529:ELF3 protein, human; D009841:Oligonucleotides; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D004247:DNA; D008156:Luciferases