Twins' Macular Pigment Optical Density Assessment and Relation with SCARB1 Gene Polymorphism.

THE AIM OF THE STUDY: to assess the influence of genetic and environmental factors using twin studies and evaluate the associations of SCARB1 gene variants (rs11057841) with AMD and MPOD. MATERIAL AND METHODS: a total of 108 healthy twins (56 MZ and 52 DZ twins) were tested in this study. The MPOD was measured using the one-wavelength reflectometry method. Fundus reflectance (Visucam 500, reflectance of a single 460 nm wavelength) was used to measure the MPOD levels, MPOD parameters including max and mean optical density (OD), and area and volume. Real-time polymerase chain reaction was used to detect single nucleotide polymorphisms. RESULTS: we detected a positive correlation of MPOD in the right and left eyes in MZ twin pairs (r = 0.830 and r = 0.860, respectively) (p < 0.0001) and a negative correlation of MPOD in the right and left eyes in DZ twin pairs (r = 0.314 and r = 0.408, respectively) (p < 0.05). The study was able to identify statistically significant differences in mean MPOD values in the right and left eyes between subjects with a wild-type CC genotype and a CT genotype with a risk allele. A decrease in the mean MPOD value was observed in group II with a CT genotype (0.110 d.u.) compared with the CC genotype (0.117 d.u.) in the right eye (p = 0.037) and in the left eye with a CT genotype (0.109 d.u.) compared with a CC genotype in the subjects (0.114 d.u.) (p = 0.038). In the right eye, in group II (0.101-0.128 d.u.), those with a CT genotype (n = 6) with one risk allele had a statistically significantly lower (0.110 d.u.) mean average MPOD value compared with those with a wild-type CC genotype (n = 25) (0.117 d.u.) (p = 0.037). CONCLUSION: this twin study showed a strong heritability of the retina pigment, which was 86% prevalent in Lithuania. Individuals with a CT genotype of the SCARB1 rs11057841 with a risk allele had statistically significantly lower mean MPOD values in both eyes compared to subjects with a wild-type CC genotype.

Association of hsa-mir-328-3p Expression in Whole Blood With Optical Density of Retinal Pigment Epithelial Cells.

AIM: To investigate the association of the pair box 6 gene (PAX6) and hsa-miR-328-3p with optical density of macular pigment. MATERIALS AND METHODS: We evaluated 112 individuals (34 with moderate myopia, eight with high-degree myopia, and 70 healthy individuals). The optical density of macular pigment was measured using single-wavelength reflectometry. DNA and RNA were extracted from whole blood samples. Expression of hsa-miR-328-3p and genotyping of single-nucleotide polymorphism of PAX6 (rs662702) were performed using Applied Biosystems 7900HT real-time polymerase chain reaction system. Optical density of retinal pigment epithelial cells was evaluated using Fundus plus camera. RESULTS: In the group with myopia, with increasing ∆Ct hsa-miR-328-3p, the median optical density of the retinal pigment epithelium decreased statistically significantly (p<0.032). No statistically significant association was found between SNP rs662702 genotype variant of the PAX6 gene and the optical density of the retinal pigment epithelium. CONCLUSION: The increased expression of hsa-miR-328-3p in the blood indicates a decrease in the optical density of the retinal pigment epithelium in those with myopia.

Association of genetic variants at CETP, AGER, and CYP4F2 locus with the risk of atrophic age-related macular degeneration.

BACKGROUND: Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly individuals. The etiology of AMD includes environmental and genetic factors. METHODS: We aimed to determine the association between CETP (rs5882; rs708272; rs3764261; rs1800775; rs2303790), AGER (rs1800624; rs1800625), and CYP4F2 (rs1558139) gene polymorphisms and development of atrophic AMD. About 52 patients with atrophic AMD and 800 healthy control subjects were evaluated. The genotyping of single-nucleotide polymorphisms in CETP, AGER, and CYP4F2 was carried out using the real-time-PCR method. RESULTS: Genetic risk models in the analysis of CETP rs5882 revealed statistically significant variables with increased risk of atrophic AMD in the codominant (p < .001), dominant (p < .001), recessive (p < .001), and additive (p < .001) models with the highest 25.4-fold increased risk of atrophic AMD in the codominant model (p < .001). The AGER rs1800625 was associated with a highly increased risk of atrophic AMD in the codominant (p < .001), recessive (p < .001), and additive (p < .001) genetic models. CONCLUSION: We identified two polymorphisms with a higher risk of atrophic AMD (CETP rs5882 and AGER rs1800625).

Independent association of whole blood miR-328 expression and polymorphism at 3'UTR of the PAX6 gene with myopia.

PURPOSE: This study aimed to find associations between miR-328 expression in whole blood, polymorphism at 3'UTR of the PAX6 gene (paired box homeotic gene 6) and myopia. METHODS: We evaluated 451 individuals (142 individuals with low, 49 with moderate and 13 with high-degree myopia, and 247 healthy individuals). DNA and RNA were extracted from peripheral blood samples. Expression of miR-328 was assessed and genotyping of single-nucleotide polymorphisms (SNPs) of the PAX6 (rs662702) performed using the Applied Biosystems 7900HT Real-Time Polymerase Chain Reaction System. RESULTS: Moderate and high degree myopia showed significant differences between TT and CT genotypes of the PAX6 gene (p < 0.001). In the myopia group, 71.4% of the subjects had the TT genotype and 28.6% had the CT genotype; meanwhile in the control group, 97.1% had the TT genotype and 2.9% had the CT genotype. The odds ratio of having moderate and/or high degree myopia for individuals with the CT genotype was 13.6 (2.865-64.55) 95% CI versus TT genotype (p = 0.001). MiR-328 results showed that ∆Ct values differed statistically significantly between the myopia and control groups. Patients with myopia in the peripheral blood cells had a higher expression of miR-328 than controls (p < 0.05). CONCLUSIONS: Significant differences were detected between the PAX6 gene (rs662702) TT and CT genotypes in moderate and high degree myopia; the risk C allele increased the risk for myopia. The expression level of miR-328 in peripheral blood cells was higher in patients with myopia than controls. We did not find the association between expression of mir-328 in the peripheral blood cells and PAX6 gene (rs662702) polymorphism comparing myopia and control groups.

The association of matrix metalloproteinases polymorphisms and interleukins in advanced age-related macular degeneration.

PURPOSE: To assess the impact of matrix metalloproteinase (MMP)1-1607 1G/2G (rs1799750), MMP7-181 A/G (rs11568818) single-nucleotide polymorphism and systemic cytokins interleukin-1 beta (IL-1ß), IL-6 levels on the development of exudative age-related macular degeneration (eAMD) Methodology: The study group comprised 282 patients with eAMD, and the control group enrolled 379 randomly selected persons. The genotyping of MMP1-1607 (rs1799750) and MMP7-181 (rs11568818) was performed by using the polymerase chain reaction-based restriction fragment length polymorphism method. To determine IL-1ß and IL-6 serum levels, the immunoenzymatic method with monoclonal antibodies coated plates was performed. RESULTS: MMP1 rs1799750 1G/2G genotype was more frequently found in the development of eAMD. It was associated with a 4.3-fold increased risk for eAMD under the codominant model and a 4.9-fold increased risk for eAMD under the overdominant model. The effect was more pronounced at the age of less than 65 years. IL-1ß concentration was significantly higher for MMP1 rs1799750 1G/1G genotype and MMP7 rs11568818 A/G genotype in eAMD patients compared with control group subjects. CONCLUSIONS: MMP1 rs1799750 1G/2G genotype was found to play a significant role in the development of eAMD at the age of less than 65 years. IL-1ß concentration was significantly higher in eAMD patients for MMP1 rs1799750 1G/1G genotype and MMP7 rs11568818 A/G genotype compared with control group subjects.