title: Quantification of Metabolic Rearrangements During Neural Stem Cells Differentiation into Astrocytes by Metabolic Flux Analysis.
abstract: Proliferation and differentiation of neural stem cells (NSCs) have a crucial role to ensure neurogenesis and gliogenesis in the mammalian brain throughout life. As there is growing evidence for the significance of metabolism in regulating cell fate, knowledge on the metabolic programs in NSCs and how they evolve during differentiation into somatic cells may provide novel therapeutic approaches to address brain diseases. In this work, we applied a quantitative analysis to assess how the central carbon metabolism evolves upon differentiation of NSCs into astrocytes. Murine embryonic stem cell (mESC)-derived NSCs and astrocytes were incubated with labelled [1-13C]glucose and the label incorporation into intracellular metabolites was followed by GC-MS. The obtained13C labelling patterns, together with uptake/secretion rates determined from supernatant analysis, were integrated into an isotopic non-stationary metabolic flux analysis (13C-MFA) model to estimate intracellular flux maps. Significant metabolic differences between NSCs and astrocytes were identified, with a general downregulation of central carbon metabolism during astrocytic differentiation. While glucose uptake was 1.7-fold higher in NSCs (on a per cell basis), a high lactate-secreting phenotype was common to both cell types. Furthermore, NSCs consumed glutamine from the medium; the highly active reductive carboxylation of alpha-ketoglutarate indicates that this was converted to citrate and used for biosynthetic purposes. In astrocytes, pyruvate entered the TCA cycle mostly through pyruvate carboxylase (81%). This pathway supported glutamine and citrate secretion, recapitulating well described metabolic features of these cells in vivo. Overall, this fluxomics study allowed us to quantify the metabolic rewiring accompanying astrocytic lineage specification from NSCs.
authors.affiliation: IBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780-901, Oeiras, Portugal.|Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, 2780-157, Oeiras, Portugal.
authors.forename: João V
authors.initials: JV
authors.lastname: Sá
authors.affiliation: The Doerenkamp-Zbinden Chair of in-vitro Toxicology and Biomedicine/Alternatives to Animal Experimentation, University of Konstanz, Konstanz, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Kleiderman
authors.affiliation: IBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780-901, Oeiras, Portugal.|Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, 2780-157, Oeiras, Portugal.
authors.forename: Catarina
authors.initials: C
authors.lastname: Brito
authors.affiliation: Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, 7491, Trondheim, Norway.|Department of Drug Design and Pharmacology Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark.
authors.forename: Ursula
authors.initials: U
authors.lastname: Sonnewald
authors.affiliation: The Doerenkamp-Zbinden Chair of in-vitro Toxicology and Biomedicine/Alternatives to Animal Experimentation, University of Konstanz, Konstanz, Germany.
authors.forename: Marcel
authors.initials: M
authors.lastname: Leist
authors.affiliation: IBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780-901, Oeiras, Portugal. anat@ibet.pt.|Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, 2780-157, Oeiras, Portugal. anat@ibet.pt.
authors.forename: Ana P
authors.initials: AP
authors.lastname: Teixeira
authors.affiliation: IBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780-901, Oeiras, Portugal. marques@ibet.pt.|Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, 2780-157, Oeiras, Portugal. marques@ibet.pt.
authors.forename: Paula M
authors.initials: PM
authors.lastname: Alves
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D064688:Metabolic Flux Analysis / Q000379:methods*; D051379:Mice; D058953:Neural Stem Cells / Q000378:metabolism*; D055495:Neurogenesis / Q000502:physiology*
keywords: Astrocytic differentiation; Carbon labelling cultures; Metabolic flux analysis; Neural stem cells