A model of glucose-6-phosphate dehydrogenase deficiency in the zebrafish

Abstract

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common genetic defect and enzymopathy worldwide, affecting approximately 400 million people and causing acute hemolysis in persons exposed to prooxidant compounds such as menthol, naphthalene, anti-malarial drugs, and fava beans. Mouse models have not been useful because of a lack of significant response to oxidative challenge. We turned to zebrafish (Danrio rerio) embryos, which develop ex utero and are transparent, allowing visualization of hemolysis. We designed morpholinos to zebrafish g6pd that were effective in reducing gene expression as shown by Western blot and G6PD enzyme activity, resulting in a brisk hemolysis and pericardial edema secondary to anemia. Titration of the g6pd knockdown allowed us to generate embryos that displayed no overt phenotype until exposed to the prooxidant compounds 1-naphthol, menthol, or primaquine, after which they developed hemolysis and pericardial edema within 48–72 hours. We were also able to show that g6pd morphants displayed significant levels of increased oxidative stress compared with controls. We anticipate that this will be a useful model of G6PD deficiency to study hemolysis as well as oxidative stress that occurs after exposure to prooxidants, similar to what occurs in G6PD-deficient persons.

Spatiotemporal expression and transcriptional regulation of heme oxygenase and biliverdin reductase genes in zebrafish (Danio rerio) suggest novel roles during early developmental periods of heightened oxidative stress

“…The significant increase in expression of these NADPH-generating enzymes at 72 hpf corresponds to the developmental timepoint at which zebrafish embryos can maintain a stable redox environment that allows for the continued maintenance of a large ratio of reduced GSH to oxidized GSH (GSSG) (Timme-Laragy et al, 2013). Interestingly, a previous zebrafsih study has demonstrated a reduction of red blood cell staining and an increase in oxidative stress in 72 hpf G6pd morphants exposed to the pro-oxidant 1-naphthol (Patrinostro et al, 2013), highlighting the important role of NADPH maintenance in protection against oxidative stress. Furthermore, the cellular redox environment of early embryos and the expression profiles of many of the NADPH-producing enzymes raise some interesting questions regarding tissue-specific production levels of NADPH during early zebrafish development.…”

Glucose-6-phosphate dehydrogenase deficiency and Alzheimer’s disease: Partners in crime? The hypothesis

“…Researchers have been trying to identify factors that increase the risk of AD such as aerobic exercise, pesticides, elevated serum cholesterol concentrations, carotenoids, abdominal obesity, and exposure to aluminum, head injury, malnutrition, immune system dysfunctions, and infectious agents [46][47][48][49][50][51]. G6PD deficiency is the most common genetic defect and enzymopathy worldwide, affecting approximately 400 million people and causing acute hemolysis in patients exposed to oxidative compounds such as menthol, naphthalene, antimalarial drugs, and fava beans [52]. G6PD is the first and the rate-limiting enzyme of the pentose phosphate pathway (PPP).…”

Establishment of a stable transgenicg6pdM1315-1443zebrafish line with glucose-6-phosphate dehydrogenase deficiency

“…Prior zebrafish models of G6PD deficiency develop pericardial edema in response to oxidative challenge and resulting anemia [16]. To evaluate for heart malformations and pericardial edema secondary to G6PD deficiency, F3 homozygous Tg(zgata1:g6pd M1315-1443 -egfp) transgenic zebrafish line were compared with wildtype.…”

“…Patrinostro et al [16] established a zebrafish models of G6PD deficiency using morpholinos targeting the 5-prime exons of g6pd, but the model is limited to transient knockdown of g6pd.…”