GLUT9 as a potential drug target for chronic kidney disease: Drug target validation by a Mendelian randomization study

Although chronic kidney disease (CKD) is recognized as a major public health concern, effective treatment strategies have yet to be developed. Identification and validation of drug targets are key issues in the development of therapeutic agents for CKD. Uric acid (UA), a major risk factor for gout, has also been suggested to be a risk factor for CKD, but the efficacy of existing urate-lowering therapies for CKD is controversial. We focused on five uric acid transporters ( ABCG2, SLC17A1, SLC22A11, SLC22A12, SLC2A9 ) as potential drug targets and evaluated the causal association between serum UA levels and estimated glomerular filtration rate (eGFR) using single-SNP Mendelian Randomization. The results showed a causal association between genetically predicted changes in serum UA levels and eGFR when genetic variants were selected from the SLC2A9 locus. Estimation based on a loss-of-function mutation (rs16890979) showed that the changes in eGFR per unit increase in serum UA level was −0.0082 ml/min/1.73 m 2 (95% CI −0.014 to −0.0025, P = 0.0051). These results indicate that SLC2A9 may be a novel drug target for CKD that preserves renal function through its urate-lowering effect.