Regulation of intracellular polyamine biosynthesis and transport by NO and cytokines TNF-alpha and IFN-gamma.
Nitric oxide (NO) has been described to exert cytostatic effects on cellular proliferation; however the mechanisms responsible for these effects have yet to be fully resolved. Polyamines, conversely, are required components of cellular proliferation. In experimental models of inflammation, a relationship between these two pathways has been suggested by the temporal regulation of a common precursor, arginine. This study was undertaken to determine the effects NO and the NO synthase (NOS)-inducing cytokines, tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma), exert on polyamine regulation. The transformed kidney proximal tubule cell line, MCT, maintains high constitutive levels of the first polyamine biosynthetic enzyme, ornithine decarboxylase (ODC). NO donors markedly suppressed ODC activity in MCT and all other cell lines examined. TNF-alpha and IFN-gamma induction of NO generation resulted in suppressed ODC activity, an effect prevented by the inducible NOS inhibitor L-N6-(1-iminoethyl)lysine (L-NIL). Dithiothreitol reversal of NO-mediated ODC suppression supports nitrosylation as the mechanism of inactivation. We also evaluated polyamine uptake, inasmuch as inhibition of ODC can result in a compensatory induction of polyamine transporters. Administration of NO donors, or TNF-alpha and IFN-gamma, suppressed [3H]putrescine uptake, thereby preventing transport-mediated reestablishment of intracellular polyamine levels. This study demonstrates the capacity of NO and inflammatory cytokines to regulate both polyamine biosynthesis and transport.
Satriano
J
J
Division of Nephrology-Hypertension, Department of Medicine, University of California, San Diego, USA. jsatriano@ucsd.edu
Ishizuka
S
S
Archer
D C
DC
Blantz
R C
RC
Kelly
C J
CJ
D016475:3T3 Cells; D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D002461:Cell Line, Transformed; D004229:Dithiothreitol / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology* / Q000502:physiology; D007687:Kidney Tubules, Proximal; D008239:Lysine / Q000031:analogs & derivatives / Q000494:pharmacology; D051379:Mice; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D052247:Nitric Oxide Synthase Type II; D009955:Ornithine Decarboxylase / Q000378:metabolism; D010396:Penicillamine / Q000031:analogs & derivatives / Q000494:pharmacology; D011073:Polyamines / Q000378:metabolism*; D051381:Rats; D026423:S-Nitroso-N-Acetylpenicillamine; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology* / Q000502:physiology
D004791:Enzyme Inhibitors; C090663:N(6)-(1-iminoethyl)lysine; D020030:Nitric Oxide Donors; D011073:Polyamines; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; C002385:linsidomine; D026423:S-Nitroso-N-Acetylpenicillamine; D007371:Interferon-gamma; D008981:Molsidomine; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C496318:Nos2 protein, rat; D009955:Ornithine Decarboxylase; D010396:Penicillamine; D008239:Lysine; D004229:Dithiothreitol