Single Nucleotide Polymorphisms in the 3'-Untranslated Region of Vascular Endothelial Growth Factor in Diabetic Retinopathy

ABSTRACT

PURPOSE: Recent studies suggest that increased expression of the vascular endothelial growth factor (VEGF) may play a role in the pathogenesis of diabetic complications. The aim of this study was to assess the potential association of VEGF gene polymorphisms with disease expression of retinopathy in patients with diabetes mellitus. METHODS: We studied 96 diabetic patients to determine whether there is an association between diabetic retinopathy in VEGF and VEGFR gene; all patients were unrelated Korean individuals (PDR, n=32; NPDR, n=25; no DMR, n=39). We analyzed VEGF and VEGFR SNP by restriction fragment mass polymorphism (RFMP). PCR was performed with primers designed to introduce a type IIS restriction endonuclease recognition sequence (FokI, BstF5I) ahead of the polymorphism site. The enzymatic cleavage of the products resulted to excision of two oligonucleotide fragments containing the variation site, and then masses of the resulting oligonucleotide fragments were examined by matrix assisted laser desorption time of flight mass spectrometry (MALDI-TOF MS). Difference are seen as the presence, absence, or mass change in peaks corresponding to the fragments affected by existence of polymorphism that have base substitution at the site of variation. RESULTS: We found that the genotype frequencies of two polymorphisms shown to be completely linked to each other (rs3025039; vf1, rs3025040; vf2) and one polymorphism (rs3812867; vfr1) within 3'-untranslated regions (3'-UTR) of the VEGF and VEGFR1 significantly differed between patients with and without retinopathy. The frequencies of the vf1, vf2 and vfr1 did not differ significantly between the NPDR and PDR group CONCLUSIONS: These data implicate the polymorphisms in the 3'-UTR of the VEGF and VEGFR1 genes as risk factors for diabetic retinopathy.