Epigenetic regulation of ABCG2 promoter methylation in adolescents with hyperuricemia

Abstract

Background: Hyperuricemia is a metabolic disorder which is characterized by increased serum uric acid levels, which can contribute to serious health issues such as gout, cardiovascular disease, and kidney damage. Epigenetic modifications, for example, DNA methylation, exert a crucial function in gene regulation and have been implicated in various metabolic disorders. The ATP-Binding Cassette Subfamily G Member 2 (ABCG2) gene is involved in uric acid excretion, and its expression can be influenced by methylation of its promoter region. Methods: This study involved the design of three guide RNA (gRNA) sequences targeting specific CpG sites within the ABCG2 promoter region. Using the Clustered Regularly Interspaced Short Palindromic Repeats/dead Cas9-Ten-Eleven Translocation 1 (CRISPR/dCas9-TET1) system, these gRNAs were employed to guide targeted demethylation of the ABCG2 promoter in cell models. A non-targeting gRNA served as a negative control. The methylation status of the ABCG2 promoter and its effect on gene expression were assessed using bisulfite sequencing and qRT-PCR. Results: Among the gRNAs tested, gRNA2 and gRNA3 effectively guided the dCas9-TET1 complex to the ABCG2 promoter, resulting in significant demethylation. gRNA2 showed the most pronounced effect, leading to a substantial increase in ABCG2 expression. Clinical data analysis revealed that adolescents with hyperuricemia had higher uric acid levels compared to healthy controls, and a higher proportion of the hyperuricemia group reported a high-protein diet, suggesting a link between diet and ABCG2 methylation. Conclusion: The findings demonstrate that targeted demethylation of the ABCG2 promoter can significantly upregulate its expression, which may help modulate uric acid levels. These results indicate that dietary factors, such as a high-protein diet, could influence ABCG2 methylation and thus impact hyperuricemia. Advanced research is necessary to explore the therapeutic potential of aiming at epigenetic modifications for the treatment of hyperuricemia.