Control of growth and differentiation of normal human epithelial cells through the manipulation of reactive nitrogen species.
In this work, we addressed the issue of whether exogenous NO and ONOO- (peroxynitrite) are able to alter growth, viability and/or differentiation of normal epithelial cells using cultured normal human keratinocytes as a model. 3-Morpholino-sydnonimine (SIN-1), a donor of both NO and O2(-)., leading to the production of ONOO-, dose-dependently inhibited growth of human keratinocytes without loss of viability. This inhibitory effect was lowered when SIN-1 was transformed into a pure NO donor by scavenging O2(-). with superoxide dismutase/catalase. Finally, scavenging NO release from SIN-1 with carboxy-1H-imidazol-1-yloxy,2-(4-carboxyp henyl)-4,5-dihydro-4,4,5,5 -tetramethyl-3-oxide (PTIO) resulted in a loss of the inhibitory effect of SIN-1. Together these findings suggest that both ONOO- and NO exert a growth inhibitory effect on human keratinocytes without cytotoxicity. Further support for this conclusion came from the treatment of human keratinocytes with the NO. donor propanamine 3-(2-hydroxy-2-nitroso-1-propyl hydrazino) or with authentic peroxynitrite. Moreover, only SIN-1 or peroxynitrite, and not NO, was able to trigger the expression of markers of terminal differentiation in human keratinocytes. From a physiological perspective, the ability of peroxynitrite, a known genotoxic and potentially carcinogenic agent, to direct proliferating keratinocytes towards terminal differentiation may be crucial to protect the genomic stability of this barrier epithelium.
Vallette
G
G
INSERM CJF 94-04, Faculté de Médecine, 1 rue Gaston Veil, 44035 Nantes, France.
Tenaud
I
I
Branka
J E
JE
Jarry
A
A
Sainte-Marie
I
I
Dreno
B
B
Laboisse
C L
CL
D002374:Catalase / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects*; D003497:Cyclic N-Oxides / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D016166:Free Radical Scavengers / Q000378:metabolism; D006801:Humans; D006834:Hydrazines / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects*; D008981:Molsidomine / Q000031:analogs & derivatives / Q000378:metabolism; D009566:Nitrates / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism
D003497:Cyclic N-Oxides; D016166:Free Radical Scavengers; D006834:Hydrazines; D007093:Imidazoles; D009566:Nitrates; C112653:PAPA NONOate; C079391:2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; C039642:peroxynitric acid; D009569:Nitric Oxide; C002385:linsidomine; D008981:Molsidomine; D002374:Catalase; D013482:Superoxide Dismutase; D013936:Thymidine