Nitric oxide maintains endothelial redox homeostasis through PKM2 inhibition

• Published in: The EMBO journal 2019-09, Vol.38 (17), p.e100938-n/a
• Main Authors: Siragusa, Mauro, Thöle, Janina, Bibli, Sofia‐Iris, Luck, Bert, Loot, Annemarieke E, de Silva, Kevin, Wittig, Ilka, Heidler, Juliana, Stingl, Heike, Randriamboavonjy, Voahanginirina, Kohlstedt, Karin, Brüne, Bernhard, Weigert, Andreas, Fisslthaler, Beate, Fleming, Ingrid
• Format: Article
• Language: English
• Subjects: Amino Acid Substitution; Angiotensin; Angiotensin II; Animals; Antioxidants; Bioavailability; cardiovascular disease; Cardiovascular diseases; Catabolism; Cells, Cultured; Deactivation; EMBO31; EMBO46; Endothelial Cells; endothelial dysfunction; Endothelium; eNOS tyrosine phosphorylation; Equivalence; Glutathione; Homeostasis; Humans; Hypertension; Inactivation; Male; Mice; Mutation; NADP; Nitric oxide; Nitric Oxide - metabolism; Nitric Oxide Synthase Type III - genetics; Nitric Oxide Synthase Type III - metabolism; Nitric-oxide synthase; Nitrosation; Oxidation-Reduction; Oxidative stress; Pentose; Pentose Phosphate Pathway; Protein Binding; Protein S; Proteins; Pyruvate kinase; Pyruvate Kinase - metabolism; Pyruvate kinase M2; Pyruvic acid; Rewiring; Substrate inhibition; S‐nitrosation
• ISSN: 0261-4189; 1460-2075
• DOI: 10.15252/embj.2018100938

Decreased nitric oxide (NO) bioavailability and oxidative stress are hallmarks of endothelial dysfunction and cardiovascular diseases. Although numerous proteins are S‐nitrosated, whether and how changes in protein S‐nitrosation influence endothelial function under pathophysiological conditions remains unknown. We report that active endothelial NO synthase (eNOS) interacts with and S‐nitrosates pyruvate kinase M2 (PKM2), which reduces PKM2 activity. PKM2 inhibition increases substrate flux through the pentose phosphate pathway to generate reducing equivalents (NADPH and GSH) and protect against oxidative stress. In mice, the Tyr656 to Phe mutation renders eNOS insensitive to inactivation by oxidative stress and prevents the decrease in PKM2 S‐nitrosation and reducing equivalents, thereby delaying cardiovascular disease development. These findings highlight a novel mechanism linking NO bioavailability to antioxidant responses in endothelial cells through S‐nitrosation and inhibition of PKM2. Synopsis Generation of nitric oxide (NO) by endothelial NO synthase (eNOS) is key for a healthy vasculature, but how protein S‐nitrosation affects endothelial cell function is poorly understood. eNOS induces S‐nitrosation and inactivation of pyruvate kinase M2, thereby triggering antioxidant responses in mice through the rewiring of endothelial cell metabolism. Under homeostatic conditions, PKM2 is part of the endothelial NO synthase (eNOS) signalosome, and is inhibited by S‐nitrosation. Inhibition of PKM2 shifts glucose catabolism towards the pentose phosphate pathway, which generates NADPH and reduced glutathione. Knock‐in mice carrying activated eNOS (Y656F‐eNOS) show enhanced endothelium‐dependent NO generation and are protected against angiotensin II‐induced hypertension and endothelial dysfunction. Graphical Abstract Endothelial nitric oxide synthase induces S‐nitrosation and inactivation of pyruvate kinase M2, triggering antioxidant responses in mice through the rewiring of endothelial cell metabolism.