The P2X7 receptor is a key modulator of aerobic glycolysis.
Ability to adapt to conditions of limited nutrient supply requires a reorganization of the metabolic pathways to balance energy generation and production of biosynthetic intermediates. Several fast-growing cells overexpress the P2X7 receptor (P2X7R) for extracellular ATP. A feature of this receptor is to allow growth in the absence of serum. We show here that transfection of P2X7R allows proliferation of P2X7R-transfected HEK293 (HEK293-P2X7) cells not only in the absence of serum but also in low (4 mM) glucose, and increases lactate output compared with mock-transfected HEK293 (HEK293-mock) cells. In HEK293-P2X7, lactate output is further stimulated upon addition of exogenous ATP or the mitochondrial uncoupler carbonylcyanide p-trifluoromethoxyphenylhydrazone (FCCP). In the human neuroblastoma cell line ACN, lactate output is also dependent on P2X7R function. P2X7R-expressing cells upregulate (a) the glucose transporter Glut1, (b) the glycolytic enzymes glyceraldehyde 3-phosphate dehydrogenase (G3PDH), (c) phosphofructokinase (PFK), (d) pyruvate kinase M2 (PKM2) and (e) pyruvate dehydrogenase kinase 1 (PDHK1); furthermore, P2X7R expression (a) inhibits pyruvate dehydrogenase (PDH) activity, (b) increases phosphorylated Akt/PKB and hypoxia-inducible factor 1α (HIF-1α) expression and (c) enhances intracellular glycogen stores. In HEK293-P2X7 cells, glucose deprivation increases lactate production, expression of glycolytic enzymes and ph-Akt/PKB level. These data show that the P2X7R has an intrinsic ability to reprogram cell metabolism to meet the needs imposed by adverse environmental conditions.
Department of Experimental and Diagnostic Medicine, Section of General Pathology, University of Ferrara, Ferrara, Italy.
F
F
Amoroso
S
S
Falzoni
E
E
Adinolfi
D
D
Ferrari
F
F
Di Virgilio
D064413:3-Phosphoinositide-Dependent Protein Kinases; D000255:Adenosine Triphosphate / Q000494:pharmacology; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000737:chemistry / Q000494:pharmacology; D045744:Cell Line, Tumor; D051272:Glucose Transporter Type 1 / Q000235:genetics / Q000378:metabolism; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics / Q000378:metabolism; D006019:Glycolysis / Q000187:drug effects; D057809:HEK293 Cells; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism; D007658:Ketone Oxidoreductases / Q000235:genetics / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D025221:Phosphofructokinases / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D011770:Pyruvate Kinase / Q000235:genetics / Q000378:metabolism; D058486:Receptors, Purinergic P2X7 / Q000378:metabolism*; D014162:Transfection; D015854:Up-Regulation
D051272:Glucose Transporter Type 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D058486:Receptors, Purinergic P2X7; D019344:Lactic Acid; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D000255:Adenosine Triphosphate; D007658:Ketone Oxidoreductases; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; C053164:pyruvate dehydrogenase (NADP+); D025221:Phosphofructokinases; D011770:Pyruvate Kinase; D064413:3-Phosphoinositide-Dependent Protein Kinases; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt