DNA damage in lens cells is considered a critical trigger for the onset of age-related cataracts (ARCs). Among DNA repair pathways, the base excision repair (BER) pathway is responsible for mending single-strand breaks in DNA. In this case-control study with 993 ARC cases and 993 healthy controls, we genotyped 9 single-nucleotide polymorphisms (SNPs) within microRNA (miRNA) regions of 6 BER pathway genes and examined their associations with ARC susceptibility. We identified rs4639:T > C in the Nei-like DNA glycosylase 2 (NEIL2) gene as significantly associated with ARCs. Individuals carrying different rs4639 alleles had distinct NEIL2 expression in lens capsule tissues from ARC cases and controls. Bioinformatics predicts that the rs4639 T allele could disrupt hsa-miR-3912-5p binding. The results of the luciferase reporter assay were in concordance with this prediction. This study has added more evidence that SNP-modified posttranscriptional gene regulation by miRNA might be a potential pathogenic mechanism of ARCs. SNPs potentially affecting miRNA binding to the 3'UTR of BER pathway genes could contribute to discrepant disease susceptibility. NEIL2-rs4639T was strongly associated with a protective role in ARCs. This protective role might be fulfilled by maintaining normal expression of NEIL2 in the mediation of disrupted binding of rs4639T with hsa-miR-3912-5p. A further study to generate model systems (cell lines or animal models) with NEIL2 variants is warranted. The results provide 2 molecular targets (e.g., NEIL2 and hsa-miR-3912-5p) for intervention strategies of ARC in the future.-Kang, L., Zou, X., Zhang, G., Xiang, J., Wang, Y., Yang, M., Chen, X., Wu, J., Guan, H. A variant in a microRNA binding site in NEIL2 3'UTR confers susceptibility to age-related cataract.
Keywords: ARC; BER pathway; DNA repair; SNP; hsa-miR-3912-5p.