title: Development of a novel mouse model of severe glucose-6-phosphate dehydrogenase (G6PD)-deficiency for in vitro and in vivo assessment of hemolytic toxicity to red blood cells.
abstract: Studies of hemolytic agents on G6PD-deficient subjects have been extensively performed on red blood cells obtained from donors, only using in vitro methods. However, there has been no adequate G6PD-deficient animal model for in vivo assessment of potentially hemolytic agents. The objective of this study is to establish a novel mouse model of severe G6PD-deficiency, with high susceptibility to hemolytic damage upon oxidative agents. To create this model, G6PD mutant Gpdx allele was introduced into the C57L/J mouse strain background by breeding program. The hemolytic toxicity of naphthalene and its metabolite α-naphthol on G6PD-deficient red blood cells was evaluated. Our data showed that the F2 homozygous Gpdx mutant with C57L/J background exhibiting the G6PD activity was 0.9±0.1 U/g Hb, level similar to those of G6PD deficiency in human. A significantly negative correlation was demonstrated between GSH percentage reduction and G6PD activity (r=-0.51, p<0.001) upon challenge of the red blood cells with alpha-naphthol in vitro. Similar correlation was also found between GSSG elevation and G6PD activity. Our in vivo studies showed that the administration of naphthalene at 250 mg/kg inflicted significant oxidative damage to the G6PD-deficient mice, as illustrated by the decrease of the GSH-to-GSSG ratio (by 34.2%, p=0.005) and the increase of the methemoglobin level (by 1.9 fold, p<0.001). Hemolytic anemia was also found in G6PD-deficient mice at this dosage of naphthalene. In summary, this novel mouse model could be utilized as a screening platform to more accurately determine the hemolytic toxicity of pharmacological agents on G6PD-deficient subjects.
authors.affiliation: Institute of Chinese Medicine, Department of Paediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR, China.
authors.forename: Chun Hay
authors.initials: CH
authors.lastname: Ko
authors.forename: Karen
authors.initials: K
authors.lastname: Li
authors.forename: Chung Leung
authors.initials: CL
authors.lastname: Li
authors.forename: Pak Cheung
authors.initials: PC
authors.lastname: Ng
authors.forename: Kwok Pui
authors.initials: KP
authors.lastname: Fung
authors.forename: Anthony Edward
authors.initials: AE
authors.lastname: James
authors.forename: Raymond Pui-On
authors.initials: RP
authors.lastname: Wong
authors.forename: Goldie Jia-Shi
authors.initials: GJ
authors.lastname: Gu
authors.forename: Tai Fai
authors.initials: TF
authors.lastname: Fok
mesh_terms: D000743:Anemia, Hemolytic / Q000139:chemically induced; D000818:Animals; D001947:Breeding / Q000379:methods; D004195:Disease Models, Animal; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D005955:Glucosephosphate Dehydrogenase Deficiency / Q000201:enzymology* / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D019803:Glutathione Disulfide / Q000378:metabolism; D053878:Hemolytic Agents / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008706:Methemoglobin / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009154:Mutation; D009281:Naphthalenes / Q000494:pharmacology; D009284:Naphthols / Q000494:pharmacology; D018384:Oxidative Stress
chemical_list: D053878:Hemolytic Agents; D009281:Naphthalenes; D009284:Naphthols; C031721:naphthalene; C029350:1-naphthol; D008706:Methemoglobin; D005954:Glucosephosphate Dehydrogenase; D005978:Glutathione; D019803:Glutathione Disulfide