The Functional Change of the P2X7R Containing the Ala348 to Thr Polymorphism is Associated with the Pathogenesis of Gout

Our previous study has shown that ATP action on P2X7R could be the second signal to induce the onset of gouty arthritis. However, the functional changes of P2X7R single nucleotide polymorphisms (SNPs) on the effects of ATP-P2X7R-IL-1 beta signaling pathway and uric acid remained unknown. We aimed to investigate the association between the functional change of P2X7R containing the Ala(348) to Thr polymorphisms (rs1718119) and the pathogenesis of gout. First, 270 gout patients and 70 hyperuricemic patients (without gout attack history in recent 5 years) were recruited for genotyping. In addition, the changes of ATP-induced pore formation were assessed in HEK-293T cells overexpressing different mutants in P2RX7, and the effects on P2X7R-NLRP3-IL-1 beta pathway activation were explored in P2RX7 overexpression THP-1 cells. The risk allele for gout was A at rs1718119, and the AA and AG genotypes exhibited a higher risk of gout. Furthermore, Ala(348) to Thr mutants increased P2X7-dependent ethidium(+) bromide uptake, upregulated IL-1 beta and NLRP3 levels as compared to the wild-type. We suggest that genetic polymorphisms of P2X7R containing the Ala(348) to Thr are associated with the increased risk of gout, showing an enhanced gain-of-function effect on the development of this disease.