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Transcriptional regulation of the human neutral ceramidase promoter
Author(s) -
O’Neill Sean Michael,
Kester Mark
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.1133.5
Subject(s) - sphingosine , ceramide , sphingosine 1 phosphate , transcriptional regulation , proinflammatory cytokine , transcription factor , biology , lipid signaling , microbiology and biotechnology , electrophoretic mobility shift assay , gene , inflammation , biochemistry , enzyme , immunology , apoptosis , receptor
Promitogenic and proinflammatory metabolites of ceramide, including sphingosine‐1‐phosphate (S‐1‐P), contribute to atherogenic plaque formation. Ceramidases play a critical role in generating S‐1‐P by hydrolyzing ceramide into sphingosine, a substrate for sphingosine kinase. The objective of the present study is to elucidate the transcriptional regulation of human neutral ceramidases (hnCDase) in vascular smooth muscle (VSM) cells. Using human genomic DNA, we cloned a 3000 base pair (bp) region upstream of the translational start site of the hnCDase gene. Luciferase reporter analyses identified a 200 bp essential promoter region with multiple candidate transcriptional response elements (TRE). Electrophoretic mobility shift assays identified several growth factor regulated transcription factors, including AP‐1, AP‐2, and NF‐Y. Mutagenic analyses of the TRE revealed that these sites regulated promoter activity. We demonstrated that PDGFββ, TGFβ, as well as serum induced hnCDase expression in human coronary artery smooth muscle cells, which correlated with elevation of the mass of hnCDase‐dependent metabolites, sphingosine and S‐1‐P. Taken together, our studies indicate that hnCDase is transcriptionally regulated by growth factors that contribute to VSM cell proliferation or inflammation, both hallmarks of atherosclerotic arterial injury. These studies were funded by NIH RO1 HL076789 to MK.