Nitric oxide switches on glycolysis through the AMP protein kinase and 6-phosphofructo-2-kinase pathway

After inhibition of cytochrome c oxidase by nitric oxide, astrocytes maintain energy production by upregulating glycolysis — a response which does not seem to be available to neurons. Here, we show that in astrocytes, after inhibition of respiration by nitric oxide, there is a rapid, cyclic GMP-independent increase in the activity of 6-phosphofructo-1-kinase (PFK1), a master regulator of glycolysis, and an increase in the concentration of its most powerful positive allosteric activator, fructose-2,6-bisphosphate (F2,6P2). In neurons, nitric oxide failed to alter F2,6P2 concentration or PFK1 activity. This failure could be accounted for by the much lower amount of 6-phosphofructo-2-kinase (PFK2, the enzyme responsible for F2,6P2 biosynthesis) in neurons. Indeed, full activation of neuronal PFK1 was achieved by adding cytosol from nitric oxide-treated astrocytes. Furthermore, using the small interfering RNA (siRNA) strategy, we demonstrated that the rapid activation of glycolysis by nitric oxide is dependent on phosphorylation of the energy charge-sensitive AMP-activated protein kinase, resulting in activation of PFK2 and protection of cells from apoptosis. Thus the virtual absence of PFK2 in neurons may explain their extreme sensitivity to energy depletion and degeneration.

[1]  D. Carling,et al.  Phosphorylation and activation of heart PFK-2 by AMPK has a role in the stimulation of glycolysis during ischaemia , 2000, Current Biology.

[2]  D. Hardie,et al.  The AMP-activated protein kinase--fuel gauge of the mammalian cell? , 1997, European journal of biochemistry.

[3]  C. Richter,et al.  Nitric oxide potently and reversibly deenergizes mitochondria at low oxygen tension. , 1994, Biochemical and biophysical research communications.

[4]  R. Sakakibara,et al.  Characterization of a human placental fructose-6-phosphate, 2-kinase/fructose-2,6-bisphosphatase. , 1997, Journal of biochemistry.

[5]  R. Bucala,et al.  An inducible gene product for 6-phosphofructo-2-kinase with an AU-rich instability element: role in tumor cell glycolysis and the Warburg effect. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[6]  R. Bernards,et al.  A System for Stable Expression of Short Interfering RNAs in Mammalian Cells , 2002, Science.

[7]  E. Schaftingen,et al.  Fructose 2,6-bisphosphate 2 years after its discovery. , 1982, The Biochemical journal.

[8]  J. L. Rosa,et al.  The human ubiquitous 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase gene (PFKFB3): promoter characterization and genomic structure. , 2001, Gene.

[9]  J. L. Rosa,et al.  Overexpression of fructose 2,6-bisphosphatase decreases glycolysis and delays cell cycle progression. , 2000, American journal of physiology. Cell physiology.

[10]  S. Moncada,et al.  Different responses of astrocytes and neurons to nitric oxide: The role of glycolytically generated ATP in astrocyte protection , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[11]  R. Bartrons,et al.  PFK-2/FBPase-2: maker and breaker of the essential biofactor fructose-2,6-bisphosphate. , 2001, Trends in biochemical sciences.

[12]  J. Bolaños,et al.  Nitric Oxide‐Mediated Inhibition of the Mitochondrial Respiratory Chain in Cultured Astrocytes , 1994, Journal of neurochemistry.

[13]  J. J. Aragón,et al.  Phosphofructokinase C isozyme from ascites tumor cells: cloning, expression, and properties. , 2000, Biochemical and biophysical research communications.

[14]  M. Rider,et al.  Role of fructose 2,6-bisphosphate in the control of glycolysis in mammalian tissues. , 1987, The Biochemical journal.

[15]  The AMP‐Activated Protein Kinase , 1997 .

[16]  O. H. Lowry,et al.  Protein measurement with the Folin phenol reagent. , 1951, The Journal of biological chemistry.

[17]  I. Kurland,et al.  6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase: a metabolic signaling enzyme. , 1995, Annual review of biochemistry.

[18]  C. Cooper,et al.  Nanomolar concentrations of nitric oxide reversibly inhibit synaptosomal respiration by competing with oxygen at cytochrome oxidase , 1994, FEBS letters.

[19]  Hans Ulrich Bergmeyer,et al.  Methods of Enzymatic Analysis , 2019 .

[20]  E. Schaftingen,et al.  A kinetic study of pyrophosphate: fructose-6-phosphate phosphotransferase from potato tubers. Application to a microassay of fructose 2,6-bisphosphate. , 1982, European journal of biochemistry.

[21]  P. Schumacker,et al.  Nitric Oxide Acutely Inhibits Neuronal Energy Production , 1999, The Journal of Neuroscience.

[22]  X. Estivill,et al.  Molecular cloning, expression, and chromosomal localization of a ubiquitously expressed human 6-phosphofructo-2-kinase/ fructose-2,6-bisphosphatase gene (PFKFB3) , 1999, Cytogenetic and Genome Research.

[23]  K. Uyeda,et al.  Regulation of Energy Metabolism in Macrophages during Hypoxia , 2001, The Journal of Biological Chemistry.

[24]  S. Moncada,et al.  Reversible inhibition of cytochrome c oxidase, the terminal enzyme of the mitochondrial respiratory chain, by nitric oxide , 1994, FEBS letters.

[25]  R. Sakakibara,et al.  Expression of human placental-type 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase in various cells and cell lines. , 1998, Biochemical and biophysical research communications.