Analysis of expression and promoter function of the human inducible nitric oxide synthase gene in DLD-1 cells and monkey hepatocytes.
Upon cytokine induction, inducible nitric oxide synthase (iNOS) mRNA and enzyme activity in DLD-1 cells reached maximal levels at 6 and 8 h, respectively. A 3.7 kb 5'-flanking region of the human iNOS gene was used to prepare luciferase reporter constructs. Upon transfection of these constructs into DLD-1 cells and primary monkey hepatocytes, significant promoter activity was detected in the absence of cytokines, and this activity decreased with successive truncations of the human iNOS promoter. No increase in luciferase activity was observed after cytokine treatment, in spite of the fact that nuclear run-on analysis indicated that iNOS induction in DLD-1 cells was due, in part, to an increase in transcription rate. These results suggest that 3.7 kb of 5'-flanking DNA do not contain all of the elements required for transcriptional induction of the human iNOS gene. This differs from the mouse iNOS gene for which 1.7 kb of 5'-flanking DNA contain most or all of the elements that control iNOS expression in mouse macrophages. Thus, important cell- and species-specific mechanisms may exist for the control of iNOS expression.
Laubach
V E
VE
University of Virginia, Department of Surgery, Charlottesville 22908, USA. vlaubach@virginia.edu
Zhang
C X
CX
Russell
S W
SW
Murphy
W J
WJ
Sherman
P A
PA
D000230:Adenocarcinoma / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D000818:Animals; D002478:Cells, Cultured; D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D003609:Dactinomycin / Q000494:pharmacology; D006207:Half-Life; D000882:Haplorhini; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D051379:Mice; D019001:Nitric Oxide Synthase / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011506:Proteins / Q000187:drug effects; D012313:RNA / Q000096:biosynthesis / Q000187:drug effects; D012333:RNA, Messenger / Q000096:biosynthesis / Q000187:drug effects; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D007375:Interleukin-1; D015850:Interleukin-6; D008070:Lipopolysaccharides; D011500:Protein Synthesis Inhibitors; D011506:Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D003609:Dactinomycin; D012313:RNA; D007371:Interferon-gamma; D019001:Nitric Oxide Synthase