Transcriptional regulation of Nox4 by histone deacetylases in human endothelial cells.
Nox4 is a member of the NADPH oxidase family, which represents a major source of reactive oxygen species (ROS) in the vascular wall. Nox4-mediated ROS production mainly depends on the expression levels of the enzyme. The present study was aimed to investigate the mechanisms of Nox4 transcription regulation by histone deacetylases (HDAC). In human umbilical vein endothelial cells (HUVEC) and HUVEC-derived EA.hy 926 cells, treatment with the pan-HDAC inhibitor scriptaid led to a marked decrease in Nox4 mRNA expression. A similar down-regulation of Nox4 mRNA expression was observed by siRNA-mediated knockdown of HDAC3. HDAC inhibition in endothelial cells was associated with enhanced histone acetylation, increased chromatin accessibility in the human Nox4 promoter region, with no significant changes in DNA methylation. In addition, we provided evidence that c-Jun played an important role in controlling Nox4 transcription. Knockdown of c-Jun with siRNA led to a down-regulation of Nox4 mRNA expression. In response to scriptaid treatment, the binding of c-Jun to the Nox4 promoter region was reduced despite the open chromatin structure. In parallel, the binding of RNA polymerase IIa to the Nox4 promoter was significantly inhibited as well, which may explain the reduction in Nox4 transcription. In conclusion, HDAC inhibition decreases Nox4 transcription in human endothelial cells by preventing the binding of transcription factor(s) and polymerase(s) to the Nox4 promoter, most likely because of a hyperacetylation-mediated steric inhibition.
Department of Pharmacology, University Medical Center, Johannes Gutenberg University, Obere Zahlbacher Strasse 67, Mainz, Germany.
Daniel
D
Siuda
Ulrich
U
Zechner
Nady
N
El Hajj
Dirk
D
Prawitt
David
D
Langer
Ning
N
Xia
Sven
S
Horke
Andrea
A
Pautz
Hartmut
H
Kleinert
Ulrich
U
Förstermann
Huige
H
Li
D001483:Base Sequence; D002478:Cells, Cultured; D019175:DNA Methylation; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology*; D005786:Gene Expression Regulation; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology; D006655:Histone Deacetylases / Q000502:physiology*; D006657:Histones / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000235:genetics*; D011401:Promoter Regions, Genetic; D016755:Proto-Oncogene Proteins c-jun / Q000502:physiology; D014158:Transcription, Genetic
D056572:Histone Deacetylase Inhibitors; D006657:Histones; D016755:Proto-Oncogene Proteins c-jun; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C498910:NOX4 protein, human; D006655:Histone Deacetylases