RESUMEN
BACKGROUND: Glutathione (GSH) is the most abundant, small biothiol antioxidant. GSH redox state (Eh) supports developmental processes, yet with disrupted GSH Eh, poor developmental outcomes may occur. The role of subcellular, compartmentalized redox environments in the context of redox regulation of differentiation is not well understood. Here, using the P19 neurogenesis model of cellular differentiation, kinetics of subcellular H2O2 availability and GSH Eh were evaluated following oxidant exposure. METHODS: Stably transfected P19 cell lines expressing H2O2 availability or GSH Eh sensors, Orp1-roGFP or Grx1-roGFP, respectively, targeted to the cytosol, mitochondria, or nucleus were used. Dynamic, compartmentalized changes in H2O2 availability and GSH Eh were measured via spectrophotometric and confocal microscopy over 120 min following treatment with H2O2 (100 µM) in both differentiated and undifferentiated cells. RESULTS: Generally, treated undifferentiated cells showed a greater degree and duration of both H2O2 availability and GSH Eh disruption than differentiated neurons. In treated undifferentiated cells, H2O2 availability was similar in all compartments. Interestingly, in treated undifferentiated cells, mitochondrial GSH Eh was most affected in both the initial oxidation and the rebound kinetics compared to other compartments. Pretreatment with an Nrf2 inducer prevented H2O2-induced effects in all compartments of undifferentiated cells. CONCLUSIONS: Disruption of redox-sensitive developmental pathways is likely stage specific, where cells that are less differentiated and/or are actively differentiating are most affected. GENERAL SIGNIFICANCE: Undifferentiated cells are more susceptible to oxidant-induced redox dysregulation but are protected by chemicals that induce Nrf2. This may preserve developmental programs and diminish the potential for poor developmental outcomes.
Asunto(s)
Peróxido de Hidrógeno , Factor 2 Relacionado con NF-E2 , Peróxido de Hidrógeno/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Glutatión/metabolismo , Oxidación-Reducción , Oxidantes , Diferenciación CelularRESUMEN
The mammalian superior colliculus and its non-mammalian homolog, the optic tectum (OT), are midbrain structures that integrate multimodal sensory inputs and guide non-voluntary movements in response to prevalent stimuli. Recent studies have implicated this structure as a possible site affected in autism spectrum disorder (ASD). Interestingly, fetal exposure to valproic acid (VPA) has also been associated with an increased risk of ASD in humans and animal models. Therefore, we took the approach of determining the effects of VPA treatment on zebrafish OT development as a first step in identifying the mechanisms that allow its formation. We describe normal OT development during the first 5â days of development and show that in VPA-treated embryos, neuronal specification and neuropil formation was delayed. VPA treatment was most detrimental during the first 3 days of development and did not appear to be linked to oxidative stress. In conclusion, our work provides a foundation for research into mechanisms driving OT development, as well as the relationship between the OT, VPA, and ASD. This article has an associated First Person interview with one of the co-first authors of the paper.