IGF-1 rs6218 polymorphisms modulate the susceptibility to age-related cataract

Single nucleotide polymorphisms (SNPs), as the most abundant form of DNA variation in the human genome, contribute to age-related cataracts (ARC) development. Apoptosis of lens epithelial cells (LECs) is closely related to ARC formation. Insulin-like growth factor 1 (IGF1) contributes to cell apoptosis regulation. Moreover, IGF1 was indicated to exhibit a close association with cataract formation. Afterward, an investigation was conducted to examine the correlation between polymorphisms in and the susceptibility to ARC. The present investigation was a case-control study. Venous blood draws were collected from the participants for DNA genotyping. Lens capsule samples were collected to detect mRNA and apoptosis. TaqMan RT-PCR was used to detect polymorphism genotypes and qRT PCR was used to detect mRNA levels in LECs. LEC apoptosis was evaluated through flow cytometry. The chi-square test was used to compare differences between ARCs and controls of each SNP. We found that the G allele frequency in the -rs6218 was higher in the ARCs than in the controls. Furthermore, it was observed that the rs6218 GG genotype exhibited a positive correlation to elevated levels of mRNA in LECs. The mRNA in the LECs and the apoptosis of LECs in nuclear type of ARCs (ARNC) was higher than the controls. The susceptibility to ARC was related to -rs6218 polymorphism, and this polymorphism is associated with expression at the mRNA level. Moreover, apoptosis in LECs of ARNCs was found to be increased.