Publication Date:
2022-05-26
Description:
Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Free Radical Biology and Medicine 65 (2013): 89-101, doi:10.1016/j.freeradbiomed.2013.06.011.
Description:
Embryonic development involves dramatic changes in cell proliferation and differentiation that must be
highly coordinated and tightly regulated. Cellular redox balance is critical for cell fate decisions, but it is
susceptible to disruption by endogenous and exogenous sources of oxidative stress. The most abundant
endogenous non-protein antioxidant defense molecule is the tri-peptide glutathione (ϒ-glutamylcysteinylglycine,
GSH), but the ontogeny of GSH concentration and redox state during early life stages
is poorly understood. Here, we describe the GSH redox dynamics during embryonic and early larval
development (0-5 days post-fertilization) in the zebrafish (Danio rerio), a model vertebrate embryo. We
measured reduced and oxidized glutathione (GSH, GSSG) using HPLC, and calculated the whole
embryo total glutathione (GSHT) concentrations and redox potentials (Eh) over 0-120 hours of zebrafish
development (including mature oocytes, fertilization, mid-blastula transition, gastrulation,
somitogenesis, pharyngula, pre-hatch embryos, and hatched eleutheroembryos). GSHT concentration
doubled between 12 hours post fertilization (hpf) and hatching. The GSH Eh increased, becoming more
oxidizing during the first 12 h, and then oscillated around -190 mV through organogenesis, followed by
a rapid change, associated with hatching, to a more negative (more reducing) Eh (-220 mV). After
hatching, Eh stabilized and remained steady through 120 hpf. The dynamic changes in GSH redox status
and concentration defined discrete windows of development: primary organogenesis, organ
differentiation, and larval growth. We identified the set of zebrafish genes involved in the synthesis,
utilization, and recycling of GSH, including several novel paralogs, and measured how expression of
these genes changes during development. Ontogenic changes in the expression of GSH-related genes
support the hypothesis that GSH redox state is tightly regulated early in development. This study
provides a foundation for understanding the redox regulation of developmental signaling and
investigating the effects of oxidative stress during embryogenesis.
Description:
This research was supported by NIH grants F32ES017585 (to ART-L),
R01ES016366 (to MEH), R01ES015912 (to JJS), a WHOI Postdoctoral Scholar award with funding
from Walter A. and Hope Noyes Smith (to ART-L), and Emory+Egelston Children’s Research Grant (to
JMH).
Keywords:
Oxidative stress
;
Embryonic development
;
Redox
;
Antioxidant
;
Gene expression
;
Glutathione
;
Zebrafish
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
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