Endothelial cell-derived nitric oxide enhances aerobic glycolysis in astrocytes via HIF-1α-mediated target gene activation.
Astrocytes exhibit a prominent glycolytic activity, but whether such a metabolic profile is influenced by intercellular communication is unknown. Treatment of primary cultures of mouse cortical astrocytes with the nitric oxide (NO) donor DetaNONOate induced a time-dependent enhancement in the expression of genes encoding various glycolytic enzymes as well as transporters for glucose and lactate. Such an effect was shown to be dependent on the hypoxia-inducible factor HIF-1α, which is stabilized and translocated to the nucleus to exert its transcriptional regulation. NO action was dependent on both the PI3K/Akt/mTOR and MEK signaling pathways and required the activation of COX, but was independent of the soluble guanylate cyclase pathway. Furthermore, as a consequence of NO treatment, an enhanced lactate production and release by astrocytes was evidenced, which was prevented by downregulating HIF-1α. Several brain cell types represent possible sources of NO. It was found that endothelial cells, which express the endothelial NO synthase (eNOS) isoform, constitutively produced the largest amount of NO in culture. When astrocytes were cocultured with primary cultures of brain vascular endothelial cells, stabilization of HIF-1α and an enhancement in glucose transporter-1, hexokinase-2, and monocarboxylate transporter-4 expression as well as increased lactate production was found in astrocytes. This effect was inhibited by the NOS inhibitor l-NAME and was not seen when astrocytes were cocultured with primary cultures of cortical neurons. Our findings suggest that endothelial cell-derived NO participates to the maintenance of a high glycolytic activity in astrocytes mediated by astrocytic HIF-1α activation.
Institute of Experimental and Clinical Pharmacology, University of Lübeck, D-23538 Lübeck, Germany.
Britta
B
Brix
Jeroen R
JR
Mesters
Luc
L
Pellerin
Olaf
O
Jöhren
D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D002867:Chromones / Q000494:pharmacology; D018920:Coculture Techniques; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000502:physiology; D006019:Glycolysis / Q000187:drug effects*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D043322:Lactase / Q000378:metabolism; D051379:Mice; D027501:Monocarboxylic Acid Transporters / Q000235:genetics / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D009569:Nitric Oxide / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D009603:Nitroso Compounds / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D014162:Transfection
D002867:Chromones; D004791:Enzyme Inhibitors; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D027501:Monocarboxylic Acid Transporters; D009025:Morpholines; D009124:Muscle Proteins; D020030:Nitric Oxide Donors; D009603:Nitroso Compounds; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C498648:Slc16a4 protein, mouse; C094210:2,2'-(hydroxynitrosohydrazono)bis-ethanamine; D009569:Nitric Oxide; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D052250:Nitric Oxide Synthase Type III; D043322:Lactase; D019331:NG-Nitroarginine Methyl Ester