hURAT1 Transgenic Mouse Model for Evaluating Targeted Urate-Lowering Agents

De, G.; Cai, W.; Yang, M.; Zhao, Q.; Yi, G.; Lin, P.; Chen, A.

doi:10.1101/2023.11.15.567192

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bioRxiv · 10.1101/2023.11.15.567192

hURAT1 Transgenic Mouse Model for Evaluating Targeted Urate-Lowering Agents

De, G.·Cai, W.·Yang, M.·Zhao, Q.·Yi, G.·Lin, P.·Chen, A.

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Abstract

ObjectiveUrate transporter 1 (URAT1), a well-established urate-lowering therapeutic target for hyperuricemia and gout treatment, expresses in the kidney proximal tubule and is responsible for uric acid (UA) reabsorption. However, non-primate animal models currently used in pharmacological studies failed to evaluate URAT1 inhibitors effectiveness because their URAT1 has a very low UA affinity compared to human URAT1, resulting in a lag in targeting drug screening and novel therapy development for gout treatment. We established a human URAT1 (hURAT1) transgenic knock-in (KI) mouse model to assess uricosuric agents effectiveness and characterize URAT1-caused pathogenesis. MethodsWe generated hURAT1 transgenic mice using CRISPR/Cas9 knock-in technique. mUrat1 knockout was achieved by replacing exon 1 coding sequence with a human SLC22A12 CDS-pA cassette. Based on the above transgenic mice, a hyperuricemia model was further established by hypoxanthine administration. ResultsThe hURAT1-KI mice successfully expressed hURAT1 protein to the apical side of the kidney proximal tubule epithelium, where a native human URAT1 kidney localization in human body. Upon hypoxanthine challenge, the blood UA level was elevated in hURAT1-KI mice, exhibiting an approximately 37% increase compared to wild-type (WT) mice. The elevated blood UA level could be alleviated by hURAT1 inhibitor benzbromarone treatment in the hURAT1-KI mice whereas no response was observed in WT littermates. Therefore, hURAT1 transgenic mice responded well to inhibitors and can be used to evaluate the therapeutic effects. ConclusionThe hURAT1-KI hyperuricaemia mouse model would be valuable for preclinical evaluation of urate-lowering agents toward gout treatment and studying UA metabolic complexities in humans.

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De, G., Cai, W., Yang, M., Zhao, Q., Yi, G., Lin, P., Chen, A.. 2023-11-17. hURAT1 Transgenic Mouse Model for Evaluating Targeted Urate-Lowering Agents. https://doi.org/10.1101/2023.11.15.567192

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