Glutathione redox dynamics and expression of glutathione-related genes in the developing embryo

• Type of Material: Article
• Authors: Alicia R Timme-Laragy, Woods Hole Oceanographic Institution; Jared V Goldstone, Woods Hole Oceanographic Institution; Barry Imhoff, Emory University; John J Stegeman, Woods Hole Oceanographic Institution; Mark E Hahn, Woods Hole Oceanographic Institution; Jason Hansen, Emory University
• Language: English
• Date: 2013-12-01
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2013 Elsevier Inc.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.freeradbiomed.2013.06.011
• Title of Journal or Parent Work: Free Radical Biology and Medicine
• Volume: 65
• Start Page: 89
• End Page: 101
• Grant/Funding Information: Emory+Egelston Children’s Research Grant (to JMH); NIH grants F32ES017585 (to ART-L), R01ES016366 (to MEH), R01ES015912 (to JJS); WHOI Postdoctoral Scholar award with funding from Walter A. and Hope Noyes Smith (to ART-L)
• Keywords: Zebrafish; ANTIOXIDANT DEFENSE; Endocrinology & Metabolism; AXIS SPECIFICATION; Gene expression; MECHANISM; Oxidative stress; INDUCED OXIDATIVE STRESS; OXYGEN; Life Sciences & Biomedicine; Biochemistry & Molecular Biology; CELL; Embryonic development; Free radicals; ZEBRAFISH; Glutathione; Antioxidant; NRF2; RAT EMBRYO; NUCLEAR GLUTATHIONE; Science & Technology; Redox
• Research Categories: Health Sciences, Public Health; Health Sciences, Immunology

Abstract

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 nonprotein antioxidant defense molecule is the tripeptide glutathione (γ-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 postfertilization) in the zebrafish (Danio rerio), a model vertebrate embryo. We measured reduced and oxidized glutathione using HPLC and calculated the whole embryo total glutathione (GSHT) concentrations and redox potentials (Eh) over 0-120 h of zebrafish development (including mature oocytes, fertilization, midblastula transition, gastrulation, somitogenesis, pharyngula, prehatch embryos, and hatched eleutheroembryos). GSHT concentration doubled between 12 h postfertilization (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.