Development of hypo and hyperuricemia in zebrafish (Danio rerio) as a potential animal model for gout studies

Abstract

Gout disease is becoming more common in most countries around the world. Gout is caused by elevated levels of serum uric acid that are deposited in joints and cause inflammation. Treatment for gout is continuously developed and new drugs are being formulated, tested, and commercialised. The use of zebrafish is gaining popularity in exploring disease mechanisms, which are complementary to other animal models such as rodents. The transparent and ex-utero development of embryo, ease of maintenance and drug administration, and cheaper and faster bioassays make zebrafish suitable for several assays. Given the specific advantages of zebrafish, the zebrafish model could have promising outcomes in giving insights to gout. The objectives of this study is to develop a zebrafish hypo- and hyperuricemia model and to identify the biomarkers by using LC-MS based metabolomics. In this study, zebrafish embryos (ZFE) were used to induce hypo- and hyperuricemia by administering allopurinol (AP) and potassium oxonate (PO), respectively, through static immersion and observed under specified parameters, namely phase of development (number of days post fertilization), days of immersion, and concentration of AP or PO. The set of parameters that has yielded the best results was selected for the LC-MS metabolomics studies. The results show that the optimum conditions were achieved at 3 dpf immersed for 2 days for the hypouricemia model, and at 4 dpf immersed for 3 days for the hyperuricemia model. The PCA score plot of the metabolomics data showed that the analysed groups were separated and distinguished. The identified metabolites which distinguish the normal zebrafish and hypo- and hyperuricemia zebrafish are Docosahexaenoic acid, Eicosapentaenoic acid, Dihydroceramide, and PE(20:4(5Z,8Z,11Z,14Z)/15:0) for AP exposed zebrafish, and Methyl (9Z)-10-oxo-6,10-diapo-6-carotenoate, 3-Oxooctadecanoic acid, (9S,10S)-9,10-dihydroxyoctadecanoate, and N-(2-Hydroxyethyl)-morpholine for PO exposed zebrafish respectively.