Deciphering regulatory patterns of inflammatory gene expression from interleukin-1-stimulated human endothelial cells.
OBJECTIVE
Endothelial cells comprise a key component of the inflammatory response. We set out to obtain a comprehensive overview of the immediate-early to early gene expression program of interleukin-1 (IL-1)-stimulated endothelial cells and to identify novel transcription factors and regulatory elements.


RESULTS
Human umbilical vein endothelial cells (HUVECs) were stimulated with IL-1 for 0, 0.5, 1, 2.5, and 6 hours and analyzed using Affymetrix U133 microarrays. A total of 137 genes were found to be regulated >4-fold, including 18 transcription factors. The expression of selected genes was confirmed by real-time polymerase chain reaction. Cluster analysis was performed in order to group genes according to their expression profiles. To identify novel transcription factor-binding sites, the corresponding promoters were extracted from databases and analyzed for regulatory elements that were over-represented in specific clusters. Several potentially novel DNA binding sites were identified, and one was shown to specifically bind an IL-1-inducible protein from HUVEC.


CONCLUSIONS
These results demonstrate that in the early phase after stimulation, IL-1 evokes a complex gene expression program that includes positive but also negative (feedback) regulators of diverse endothelial cell functions. Furthermore, the identification of a new promoter regulatory element demonstrates the feasibility of the bioinformatics-driven approach to discover novel regulatory mechanisms.
Mayer
Herbert
H
Department of Vascular Biology and Thrombosis Research, University of Vienna, Vienna, Austria.
Bilban
Martin
M
Kurtev
Vladislav
V
Gruber
Florian
F
Wagner
Oswald
O
Binder
Bernd R
BR
de Martin
Rainer
R
D001665:Binding Sites; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D019295:Computational Biology / Q000379:methods; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D007249:Inflammation / Q000235:genetics / Q000503:physiopathology*; D007375:Interleukin-1 / Q000494:pharmacology*; D008957:Models, Genetic; D005810:Multigene Family / Q000187:drug effects; D000072000:NF-KappaB Inhibitor alpha; D011401:Promoter Regions, Genetic / Q000187:drug effects; D012045:Regulatory Sequences, Nucleic Acid; D012984:Software; D014157:Transcription Factors / Q000378:metabolism
D020672:I-kappa B Proteins; D007375:Interleukin-1; C000606204:NFKBIA protein, human; D014157:Transcription Factors; D000072000:NF-KappaB Inhibitor alpha