Effect of IBD sera on expression of inducible and endothelial nitric oxide synthase in human umbilical vein endothelial cells.
OBJECTIVE
To study the expression of endothelial and inducible nitric oxide synthases (eNOS and iNOS) and their role in inflammatory bowel disease (IBD).


METHODS
We examined the effect of sera obtained from patients with active Crohn's disease (CD) and ulcerative colitis (UC) on the function and viability of human umbilical vein endothelial cells (HUVEC). HUVECs were cultured for 0-48 h in the presence of a medium containing pooled serum of healthy controls, or serum from patients with active CD or UC. Expression of eNOS and iNOS was visualized by immunofluorescence, and quantified by the densitometry of Western blots. Proliferation activity was assessed by computerized image analyses of Ki-67 immunoreactive cells, and also tested in the presence of the NOS inhibitor, 10(-4) mol/L L-NAME. Apoptosis and necrosis was examined by the annexin-V-biotin method and by propidium iodide staining, respectively.


RESULTS
In HUVEC immediately after exposure to UC, serum eNOS was markedly induced, reaching a peak at 12 h. In contrast, a decrease in eNOS was observed after incubation with CD sera and the eNOS level was minimal at 20 h compared to control (18%+/-16% vs 23%+/-15% P<0.01). UC or CD serum caused a significant increase in iNOS compared to control (UC: 300%+/-21%; CD: 275%+/-27% vs 108%+/-14%, P<0.01). Apoptosis/necrosis characteristics did not differ significantly in either experiment. Increased proliferation activity was detected in the presence of CD serum or after treatment with L-NAME. Cultures showed tube-like formations after 24 h treatment with CD serum.


CONCLUSIONS
IBD sera evoked changes in the ratio of eNOS/iNOS, whereas did not influence the viability of HUVEC. These involved down-regulation of eNOS and up-regulation of iNOS simultaneously, leading to increased proliferation activity and possibly a reduced anti-inflammatory protection of endothelial cells.
2nd Department of Internal Medicine, Medical and Health Science Center, University of Debrecen, Nagyerdei körút 98, Debrecen H-4001, Hungary. palatka@jaguar.unideb.hu
Károly
K
Palatka
Zoltán
Z
Serfozo
Zoltán
Z
Veréb
Róbert
R
Bátori
Beáta
B
Lontay
Zoltán
Z
Hargitay
Zoltán
Z
Nemes
Miklós
M
Udvardy
Ferenc
F
Erdodi
István
I
Altorjay
D000293:Adolescent; D000328:Adult; D017209:Apoptosis; D015153:Blotting, Western; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D003093:Colitis, Ulcerative / Q000097:blood / Q000503:physiopathology; D003424:Crohn Disease / Q000097:blood / Q000503:physiopathology; D017077:Culture Media, Conditioned; D042783:Endothelial Cells / Q000201:enzymology; D004730:Endothelium, Vascular / Q000201:enzymology / Q000502:physiology*; D005260:Female; D005455:Fluorescent Antibody Technique; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000097:blood / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000235:genetics*; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000235:genetics*; D014471:Umbilical Veins / Q000166:cytology / Q000201:enzymology*
D017077:Culture Media, Conditioned; C496314:NOS3 protein, human; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D019331:NG-Nitroarginine Methyl Ester