title: Astrocyte-neuron lactate shuttle may boost more ATP supply to the neuron under hypoxic conditions--in silico study supported by in vitro expression data.
abstract: BACKGROUND
  Neuro-glial interactions are important for normal functioning of the brain as well as brain energy metabolism. There are two major working models--in the classical view, both neurons and astrocytes can utilize glucose as the energy source through oxidative metabolism, whereas in the astrocyte-neuron lactate shuttle hypothesis (ANLSH) it is the astrocyte which can consume glucose through anaerobic glycolysis to pyruvate and then to lactate, and this lactate is secreted to the extracellular space to be taken up by the neuron for further oxidative degradation.
  
  
  RESULTS
  In this computational study, we have included hypoxia-induced genetic regulation of these enzymes and transporters, and analyzed whether the ANLSH model can provide an advantage to either cell type in terms of supplying the energy demand. We have based this module on our own experimental analysis of hypoxia-dependent regulation of transcription of key metabolic enzymes. Using this experimentation-supported in silico modeling, we show that under both normoxic and hypoxic conditions in a given time period ANLSH model does indeed provide the neuron with more ATP than in the classical view.
  
  
  CONCLUSIONS
  Although the ANLSH is energetically more favorable for the neuron, it is not the case for the astrocyte in the long term. Considering the fact that astrocytes are more resilient to hypoxia, we would propose that there is likely a switch between the two models, based on the energy demand of the neuron, so as to maintain the survival of the neuron under hypoxic or glucose-and-oxygen-deprived conditions.
authors: Chemical Engineering Department, Yeditepe University, Istanbul, Turkey. seda.genc@yeditepe.edu.tr
authors: Seda
authors: S
authors: Genc
authors: Isil A
authors: IA
authors: Kurnaz
authors: Mustafa
authors: M
authors: Ozilgen
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D015687:Cell Hypoxia; D019295:Computational Biology; D003198:Computer Simulation; D005786:Gene Expression Regulation; D005947:Glucose / Q000378:metabolism; D007700:Kinetics; D019344:Lactic Acid / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D016716:PC12 Cells; D051381:Rats
chemical_list: D019344:Lactic Acid; D000255:Adenosine Triphosphate; D005947:Glucose