Induction of cyclooxygenase-2 by overexpression of the human catalase gene in cerebral microvascular endothelial cells.
Prostaglandin (PG) formation by the inducible (type 2) cyclooxygenase (COX-2) and reactive oxygen species (ROS) have been proposed to play important roles in cerebrovascular pathological processes. To explore the relationship between ROS and COX-2 expression, adenovirus (Ad) vectors containing cDNA for human antioxidant enzymes including catalase (AdCAT:), copper/zinc superoxide dismutase (AdCu/ZnSOD), and manganese superoxide dismutase (AdMnSOD) were transferred into murine cerebral microvascular endothelial cells. AdCAT: (100 multiplicity of infection) infection increased the content and enzymatic activity of cellular Cat threefold and decreased the intracellular peroxide level. The expression of COX-2 mRNA and protein in cell lysates was up-regulated, and the amount of PGE(2) formed from exogenous arachidonic acid increased following AdCAT: infection in a dose-dependent manner, paralleling the expression of COX-2 protein. The AdCAT:-induced increase in PGE(2) formation was inhibited by NS-398, a selective inhibitor of COX-2 enzymatic activity. AdCAT: infection did not change the expression of the constitutive (type 1) COX protein. Although AdCu/ZnSOD and AdMnSOD infection increased the expression of superoxide dismutase proteins, COX-2 expression was not induced. An in vitro nuclear transcription assay indicated that overexpression of the Cat gene increases the transcription of the COX-2 gene. Furthermore, the stability of COX-2 mRNA induced by lipopolysaccharide was increased after AdCAT: gene transfer. These results indicate that AdCAT: gene transfer induces the transcriptional activation of the COX-2 gene and increases COX-2 mRNA stability. Therefore, peroxide may have regulatory effect on COX-2 function in the cerebral microcirculation.
Fang
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X
Department of Biochemistry University of Iowa, Iowa City, Iowa, USA xiang-fang@uiowa.edu
Moore
A S
AS
Nwankwo
J O
JO
Weintraub
L N
LN
Oberley
W L
WL
Snyder
D G
DG
Spector
A A
AA
D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D002374:Catalase / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D002560:Cerebrovascular Circulation; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D004790:Enzyme Induction; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D008565:Membrane Proteins; D051379:Mice; D008833:Microcirculation; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis / Q000235:genetics*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D001616:beta-Galactosidase / Q000235:genetics
D007527:Isoenzymes; D008565:Membrane Proteins; D017382:Reactive Oxygen Species; D016718:Arachidonic Acid; D002374:Catalase; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D001616:beta-Galactosidase; D015232:Dinoprostone