title: Differential regulation of metabolism by nitric oxide and S-nitrosothiols in endothelial cells.
abstract: S-nitrosation of thiols in key proteins in cell signaling pathways is thought to be an important contributor to nitric oxide (NO)-dependent control of vascular (patho)physiology. Multiple metabolic enzymes are targets of both NO and S-nitrosation, including those involved in glycolysis and oxidative phosphorylation. Thus it is important to understand how these metabolic pathways are integrated by NO-dependent mechanisms. Here, we compared the effects of NO and S-nitrosation on both glycolysis and oxidative phosphorylation in bovine aortic endothelial cells using extracellular flux technology to determine common and unique points of regulation. The compound S-nitroso-L-cysteine (L-CysNO) was used to initiate intracellular S-nitrosation since it is transported into cells and results in stable S-nitrosation in vitro. Its effects were compared with the NO donor DetaNONOate (DetaNO). DetaNO treatment caused only a decrease in the reserve respiratory capacity; however, L-CysNO impaired both this parameter and basal respiration in a concentration-dependent manner. In addition, DetaNO stimulated extracellular acidification rate (ECAR), a surrogate marker of glycolysis, whereas L-CysNO stimulated ECAR at low concentrations and inhibited it at higher concentrations. Moreover, a temporal relationship between NO- and S-nitrosation-mediated effects on metabolism was identified, whereby NO caused a rapid impairment in mitochondrial function, which was eventually overwhelmed by S-nitrosation-dependent processes. Taken together, these results suggest that severe pharmacological nitrosative stress may differentially regulate metabolic pathways through both intracellular S-nitrosation and NO-dependent mechanisms. Moreover, these data provide insight into the role of NO and related compounds in vascular (patho)physiology.
authors.affiliation: Department of Biophysics, Redox Biology Program, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
authors.forename: Anne R
authors.initials: AR
authors.lastname: Diers
authors.forename: Katarzyna A
authors.initials: KA
authors.lastname: Broniowska
authors.forename: Victor M
authors.initials: VM
authors.lastname: Darley-Usmar
authors.forename: Neil
authors.initials: N
authors.lastname: Hogg
mesh_terms: D000227:Adenine Nucleotides / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D003545:Cysteine / Q000031:analogs & derivatives / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D006019:Glycolysis / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D015538:Nitrosation; D009603:Nitroso Compounds / Q000494:pharmacology; D010085:Oxidative Phosphorylation / Q000187:drug effects; D026403:S-Nitrosothiols / Q000378:metabolism* / Q000494:pharmacology; D013312:Stress, Physiological / Q000187:drug effects; D013997:Time Factors
chemical_list: D000227:Adenine Nucleotides; D020030:Nitric Oxide Donors; D009603:Nitroso Compounds; D026403:S-Nitrosothiols; C094210:2,2'-(hydroxynitrosohydrazono)bis-ethanamine; D009569:Nitric Oxide; C021315:S-nitrosocysteine; D003545:Cysteine