AIM: To analyze the relationship between rs128912 single nucleotide polymorphism(SNP)in the promoter region of Toll-like receptor 3(TLR3)gene and cataract in Chinese Han population.

METHODS: A total of 263 patients with cataract admitted to our hospital from June 2019 to June 2021 were selected as study group, and 150 patients with lens dislocation were included in control group. Western blotting was used to detect the expression of TLR3 protein in the anterior capsular tissues of lens in the two groups, and direct sequencing method was applied to analyze the polymorphism of rs128912 locus in the promoter region of TLR3 gene. The expression of peripheral blood TLR3 mRNA of patients with different genotypes was detected by real-time quantitative polymerase chain reaction(RT-qPCR).

RESULTS: The expression level of TLR3 protein in the anterior capsular tissues in the study group was higher than that in the control group(P<0.05). The frequencies of genotypes(AA, AT, TT)at rs128912 locus in the TLR3 gene promoter region in the study group and the control group were in accordance with Hardy-Weinberg genetic equilibrium, and there were differences in the frequencies of genotypes(AA, AT, TT)and frequencies of alleles(A, T)at rs128912 locus in the TLR3 gene promoter region between both groups(P<0.05). The relative expression level of peripheral blood TLR3 mRNA in patients with TT genotype in the study group was higher than that in patients with AA or AT genotypes(P<0.05).

CONCLUSION: The expression of TLR3 protein in anterior capsular tissues of lens of patients with cataract is significantly up-regulated, and rs128912 locus polymorphism in the TLR3 gene promoter region is related to the susceptibility of cataract in Chinese Han population, and people with TT genotype are more prone to cataract.