PUBLICATION
Metabolic interaction of hydrogen peroxide and hypoxia in zebrafish fibroblasts
- Authors
- Dikova, V., Vorhauser, J., Geng, A., Pelster, B., Sandbichler, A.M.
- ID
- ZDB-PUB-191120-1
- Date
- 2019
- Source
- Free radical biology & medicine 152: 469-481 (Journal)
- Registered Authors
- Pelster, Bernd
- Keywords
- Diphenyleneiodonium chloride, Glycolysis, Hydrogen peroxide, Hypoxia, Pentose phosphate pathway, Reactive oxygen species, Respiration, Zebrafish, roGFP2-Orp1
- MeSH Terms
-
- Animals
- Fibroblasts
- Hydrogen Peroxide*
- Hypoxia
- Reactive Oxygen Species
- Zebrafish*
- PubMed
- 31740229 Full text @ Free Radic. Biol. Med.
Citation
Dikova, V., Vorhauser, J., Geng, A., Pelster, B., Sandbichler, A.M. (2019) Metabolic interaction of hydrogen peroxide and hypoxia in zebrafish fibroblasts. Free radical biology & medicine. 152:469-481.
Abstract
Cells require oxygen for aerobic metabolism, which may also result in the production of reactive oxygen species (ROS) as a by-product. Under low oxygen conditions, ROS formation has been reported to either increase or decrease. We addressed this physiological response for the first time in zebrafish embryonic fibroblasts (Z3) and used a hydrogen peroxide (H2O2)-specific fluorescent protein (roGFP2-Orp1) either targeted to the mitochondria or expressed in the cytosol. Microfluidic live-cell imaging measurements showed that oxygen deprivation in Z3 cells results in decreased or stable H2O2 levels within the mitochondria or the cytosol, respectively, and that the reductive shift recorded in the mitochondrial matrix is directly dependent on oxygen concentration. The response was accompanied by a transient increase in extracellular acidification rate (ECAR) and a lower cellular reducing potential as assessed by the viability stain alamarBlue. Complex I and III inhibition with Rotenone and Antimycin A led to H2O2 production under normoxia but these inhibitors were not able to avert the reductive shift under hypoxia. Only by system-wide inhibition of flavin-containing oxidases with Diphenyleneiodonium (DPI) were we able to decrease the reductive shift. Since DPI also led to a strong increase in ECAR we found that, in order to keep the cytosolic H2O2 levels stable, glycolytic metabolism was of fundamental importance. According to our experiments with the glucose-6-phopshate dehydrogenase inhibitor 6-Aminonicotinamide, this was attributable to the pentose phosphate pathway producing reducing equivalents required for ROS degradation.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
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