title: Nitric oxide stimulates PC12 cell proliferation via cGMP and inhibits at higher concentrations mainly via energy depletion.
abstract: We investigated the mechanisms by which nitric oxide (NO) from an NO donor (DETA/NO) regulates proliferation of pheochromocytoma PC12 cells. The NO donor stimulated proliferation at low concentrations, but reversibly and completely inhibited proliferation at higher concentrations. The stimulation (but not the inhibition) of proliferation was apparently due to NO stimulation of soluble guanylate cyclase to produce cGMP, as it was prevented by a specific cyclase inhibitor (ODQ), and replicated by a cell-permeable form of cGMP. The NO-induced cytostasis was not reversed by inhibitors of MEK kinase or poly(ADP-ribose)polymerase, or by treatments that bypass inhibition of ribonucleotide reductase or ornithine decarboxylase. Cytostatic concentrations of DETA/NO strongly inhibited respiration of PC12 cells, and specific respiratory inhibitors (rotenone, myxothiazol, or azide) caused complete cytostasis. Uridine and pyruvate reversed the cytostasis induced by the specific respiratory inhibitors, but not that induced by DETA/NO. However, the combination of uridine, pyruvate, and N-acetyl-cysteine did reverse DETA/NO-induced cytostasis. DETA/NO strongly and progressively inhibited glycolysis measured by glucose consumption, lactate production, and ATP level, and a specific glycolytic inhibitor (5 mM 2-deoxy-d-glucose) caused complete cytostasis. Our results indicate that NO at low concentrations increases cell proliferation via cGMP, while high concentrations of NO block proliferation via inhibition of both glycolysis and respiration, causing energy depletion.
authors.affiliation: Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, UK.
authors.forename: Anna
authors.initials: A
authors.lastname: Bal-Price
authors.forename: Joanne
authors.initials: J
authors.lastname: Gartlon
authors.forename: Guy C
authors.initials: GC
authors.lastname: Brown
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D019069:Cell Respiration / Q000187:drug effects; D006152:Cyclic GMP / Q000378:metabolism*; D006019:Glycolysis / Q000187:drug effects; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008262:Macrophage Activation; D008264:Macrophages / Q000187:drug effects / Q000201:enzymology; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000378:metabolism; D065108:Ornithine Decarboxylase Inhibitors; D016716:PC12 Cells; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D019289:Pyruvic Acid / Q000494:pharmacology; D051381:Rats; D012264:Ribonucleotide Reductases / Q000037:antagonists & inhibitors; D014226:Triazenes / Q000494:pharmacology; D014529:Uridine / Q000494:pharmacology
chemical_list: C105351:1-hydroxy-2-oxo-3,3-bis(2-aminoethyl)-1-triazene; D020030:Nitric Oxide Donors; D065108:Ornithine Decarboxylase Inhibitors; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D014226:Triazenes; D009569:Nitric Oxide; D019289:Pyruvic Acid; D052247:Nitric Oxide Synthase Type II; D012264:Ribonucleotide Reductases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D014529:Uridine; D000111:Acetylcysteine