TY - JOUR
T1 - Stage-specific metabolic features of differentiating neurons
T2 - Implications for toxicant sensitivity
AU - Delp, Johannes
AU - Gutbier, Simon
AU - Cerff, Martin
AU - Zasada, Christin
AU - Niedenführ, Sebastian
AU - Zhao, Liang
AU - Smirnova, Lena
AU - Hartung, Thomas
AU - Borlinghaus, Hanna
AU - Schreiber, Falk
AU - Bergemann, Jörg
AU - Gätgens, Jochem
AU - Beyss, Martin
AU - Azzouzi, Salah
AU - Waldmann, Tanja
AU - Kempa, Stefan
AU - Nöh, Katharina
AU - Leist, Marcel
N1 - Publisher Copyright:
© 2017
PY - 2018/9/1
Y1 - 2018/9/1
N2 - Developmental neurotoxicity (DNT) may be induced when chemicals disturb a key neurodevelopmental process, and many tests focus on this type of toxicity. Alternatively, DNT may occur when chemicals are cytotoxic only during a specific neurodevelopmental stage. The toxicant sensitivity is affected by the expression of toxicant targets and by resilience factors. Although cellular metabolism plays an important role, little is known how it changes during human neurogenesis, and how potential alterations affect toxicant sensitivity of mature vs. immature neurons. We used immature (d0) and mature (d6) LUHMES cells (dopaminergic human neurons) to provide initial answers to these questions. Transcriptome profiling and characterization of energy metabolism suggested a switch from predominantly glycolytic energy generation to a more pronounced contribution of the tricarboxylic acid cycle (TCA) during neuronal maturation. Therefore, we used pulsed stable isotope-resolved metabolomics (pSIRM) to determine intracellular metabolite pool sizes (concentrations), and isotopically non-stationary 13C-metabolic flux analysis (INST 13C-MFA) to calculate metabolic fluxes. We found that d0 cells mainly use glutamine to fuel the TCA. Furthermore, they rely on extracellular pyruvate to allow continuous growth. This metabolic situation does not allow for mitochondrial or glycolytic spare capacity, i.e. the ability to adapt energy generation to altered needs. Accordingly, neuronal precursor cells displayed a higher sensitivity to several mitochondrial toxicants than mature neurons differentiated from them. In summary, this study shows that precursor cells lose their glutamine dependency during differentiation while they gain flexibility of energy generation and thereby increase their resistance to low concentrations of mitochondrial toxicants.
AB - Developmental neurotoxicity (DNT) may be induced when chemicals disturb a key neurodevelopmental process, and many tests focus on this type of toxicity. Alternatively, DNT may occur when chemicals are cytotoxic only during a specific neurodevelopmental stage. The toxicant sensitivity is affected by the expression of toxicant targets and by resilience factors. Although cellular metabolism plays an important role, little is known how it changes during human neurogenesis, and how potential alterations affect toxicant sensitivity of mature vs. immature neurons. We used immature (d0) and mature (d6) LUHMES cells (dopaminergic human neurons) to provide initial answers to these questions. Transcriptome profiling and characterization of energy metabolism suggested a switch from predominantly glycolytic energy generation to a more pronounced contribution of the tricarboxylic acid cycle (TCA) during neuronal maturation. Therefore, we used pulsed stable isotope-resolved metabolomics (pSIRM) to determine intracellular metabolite pool sizes (concentrations), and isotopically non-stationary 13C-metabolic flux analysis (INST 13C-MFA) to calculate metabolic fluxes. We found that d0 cells mainly use glutamine to fuel the TCA. Furthermore, they rely on extracellular pyruvate to allow continuous growth. This metabolic situation does not allow for mitochondrial or glycolytic spare capacity, i.e. the ability to adapt energy generation to altered needs. Accordingly, neuronal precursor cells displayed a higher sensitivity to several mitochondrial toxicants than mature neurons differentiated from them. In summary, this study shows that precursor cells lose their glutamine dependency during differentiation while they gain flexibility of energy generation and thereby increase their resistance to low concentrations of mitochondrial toxicants.
KW - C labeling experiment
KW - Developmental neurotoxicity
KW - Energy metabolism
KW - Metabolic flux
KW - Metabolomics
KW - Oxygen consumption
UR - http://www.scopus.com/inward/record.url?scp=85040229837&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85040229837&partnerID=8YFLogxK
U2 - 10.1016/j.taap.2017.12.013
DO - 10.1016/j.taap.2017.12.013
M3 - Article
C2 - 29278688
AN - SCOPUS:85040229837
SN - 0041-008X
VL - 354
SP - 64
EP - 80
JO - Toxicology and Applied Pharmacology
JF - Toxicology and Applied Pharmacology
ER -