[Explore the genotype characteristics of DNA repair enzyme XRCC1 and XPD in the lens epithelium associated with free radical level in the age-related cataract patients].

OBJECTIVE: To explore the genotype characteristics of DNA repair enzyme XPD-751 and XRCC1-399 in the lens epithelium of cataract patients, and difference in free radical level.

METHODS: The genome DNA was extracted from respective lens epithelium of 30 cataract patients, their peripheral blood and 12 normal control's peripheral blood by using a Genomic DNA kit, and the polymorphisms of DNA repair enzymes XPD-751 and XRCC1-399 were examined by PCR-RFLP technique. Meanwhile, that of the cultured normal human lens epithelial SRA01/04 cells was carried out same way as reference control. Besides, the free radical level was detected by related kit.

RESULTS: The XRCC1-Gln399Gln or XPD-Lys751Lys genotype was found in the normal control group and cultured human SRA01/04 cells, while the polymorphism of XPD-Lys751Gln could be found in both lens epithelium and blood cells of the cataract patient group. However, there was no difference in XRCC1-399 phenotype between the patient and the normal control groups. There is difference in free radical level between the cataract (0.204 ± 0.07; 0.188 ± 0.07) and healthy subjects (t = 211.20, P < 0.05).

CONCLUSION: The polymorphism of XPD-Lys751Gln can be found in the lens epithelium of cataract patient group, suggesting that there may be association among the XPD-751 polymorphism with higher free radical level in the age-related cataract disease.