Curcumin regulates intracellular calcium release and inhibits oxidative stress parameters, VEGF, and caspase-3/-9 levels in human retinal pigment epithelium cells.

In this study, we aimed to observe whether curcumin (cur), a polyphenolic compound derived from the dietary spice turmeric, a yellow substance obtained from the root of the plant Curcuma longa Linn, has any protective effect against blue light irradiation in human retinal pigment epithelium (ARPE-19) cells. For this purpose, we evaluated the intracellular calcium release mechanism, poly ADP ribose polymerase (PARP), procaspase-3/-9 protein expression levels, caspase activation, and reactive oxygen species levels. ARPE-19 cells were divided into four main groups, such as control, cur, blue light, and cur + blue light. Results were evaluated by Kruskal-Wallis and Mann-Whitney U tests as post hoc tests. The cells in cur and cur + blue light samples were incubated with 20 µM cur. Blue light exposure was performed for 24 h in an incubator. Lipid peroxidation and cytosolic-free Ca2+ [Ca2+]i concentrations were higher in the blue light exposure samples than in the control samples; however, their levels were determined as significantly lower in the cur and cur + blue light exposure samples than in the blue light samples alone. PARP and procaspase-3 levels were significantly higher in blue light samples. Cur administration significantly decreased PARP and procaspase-3 expression levels. Reduced glutathione and glutathione peroxidase values were lower in the blue light exposure samples, although they were higher in the cur and cur + blue light exposure samples. Caspase-3 and -9 activities were lower in the cur samples than in the blue light samples. Moreover, vascular endothelial growth factor (VEGF) levels were significantly higher in the blue light exposure samples. In conclusion, cur strongly induced regulatory effects on oxidative stress, intracellular Ca2+ levels, VEGF levels, PARP expression levels, and caspase-3 and -9 values in an experimental oxidative stress model in ARPE-19 cells.

Next-generation sequencing analysis of the ARMS2 gene in Turkish exudative age-related macular degeneration patients.

Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries. It is a complex disease with both genetic and environmental risk factors. To improve clinical management of this condition, it is important to develop risk assessment and prevention strategies for environmental influences, and establish a more effective treatment approach. The aim of the present study was to investigate age-related maculopathy susceptibility protein 2 (ARMS2) gene sequences among Turkish patients with exudative AMD. In addition to 39 advanced exudative AMD patients, 250 healthy individuals for whom exome sequencing data were available were included as a control group. Patients with a history of known environmental and systemic AMD risk factors were excluded. Genomic DNA was isolated from peripheral blood and analyzed using next-generation sequencing. All coding exons of the ARMS2 gene were assessed. Three different ARMS2 sequence variations (rs10490923, rs2736911, and rs10490924) were identified in both the patient and control group. Within the control group, two further ARMS2 gene variants (rs7088128 and rs36213074) were also detected. Logistic regression analysis revealed a relationship between the rs10490924 polymorphism and AMD in the Turkish population.

Effect of ARMS2 gene polymorphism on intravitreal ranibizumab treatment for neovascular age-related macular degeneration.

Age-related macular degeneration (AMD) is a leading cause of blindness in developed countries. The ARMS2 gene has been found to be associated with AMD. Currently, intravitreal ranibizumab (IVR) treatment is one of the widely used treatments for neovascular AMD. The aim of this study was to investigate the association between the genotype of ARMS2 rs10490924 polymorphism and IVR treatment responsiveness in patients with neovascular AMD. The study included 39 patients with advanced neovascular AMD (patient group) and 250 healthy individuals with exome sequencing data (control group). The patient group was divided into three subgroups: GG (N = 10), TG (N = 14), and TT (N = 15). Before IVR treatment, all patients had intraretinal or subretinal fluid or both. They received three monthly IVR-injection treatments. One month after the third injection, the patients were evaluated as either "responders" or "non-responders" based on the presence or absence of intraretinal or subretinal fluid or both. The patient subgroups TG and TT had an 8.56- and 39-fold higher risk of AMD, respectively, than patient subgroup GG had. The allele frequency was 0.537 and 0.10 in the patient and control groups, respectively. Within the patient subgroup TT, there was a significant difference between the "responders" and "non-responders" (P = 0.025). In conclusion, in neovascular AMD patients undergoing IVR treatment, TT genotype tended to be a better predictor of good short-term treatment response, compared to the GG and TG genotypes. Further studies using confirmed genetic biomarkers for individualized optimal treatments are required.

Analysis of ELOVL4 and PRPH2 genes in Turkish Stargardt disease patients.

Stargardt disease (STGD) is an inherited genetic eye condition involving bilateral macular dystrophy leading to progressive central vision loss. It is the most common form of autosomal recessive juvenile macular dystrophy. In this study, ELOVL4 and PRPH2 genes were analyzed in 30 STGD probands for genetic variations using next-generation sequencing. In the patient group, two genetic variants in exon 6 of ELOVL4, and three in exon 3 of PRPH2 were detected. All sequence modifications in both ELOVL4 and PRPH2 were recorded, including those of a non-pathogenic nature. In the control group, four different genetic variations were detected in ELOVL4, and five in PRPH2. STGD patients of different ethnicities may carry distinct ELOVL4 and PRPH2 sequence variants. We believe that the genetic variations identified in this study may be related to STGD etiopathogenesis.

Novel visual system homeobox 1 gene mutations in Turkish patients with keratoconus.

The aim of this study was to screen the visual system homeobox 1 (VSX1) gene in Turkish patients with keratoconus (KC). The patient group consisted of 44 patients who had undergone corneal transplant surgery before the age of 30, for advanced and rapidly progressive KC. The control group comprised 250 healthy individuals. We detected two missense mutations, D144N and D295Y, in exon 2 and exon 5 of the VSX1 gene, respectively, using next-generation sequencing analysis. The pathologic effects of the D144N and D295Y missense mutations on protein function were determined with bioinformatic analysis tools, SIFT, PolyPhen, and MutationTaster. Aspartic acid at the 144th position was more preserved among species than aspartic acid at the 295th position of the VSX1 protein. In the control group, five different genetic variations were detected, two of which (rs8123716 and rs12480307) were synonymous with variations in the patient group. Our results suggested that the D144N and D295Y mutations might have a role in the pathogenesis of KC disease.

Alterations in central retinal sensitivity after intravitreal triamcinolone injection for diffuse diabetic macular edema.

PURPOSE: To evaluate alterations in central retinal sensitivity following intravitreal triamcinolone injection in patients with diffuse diabetic macular edema that persisted after laser treatment. METHODS: Fourteen eyes of 14 patients that received 4 mg 0.1 cc intravitreal triamcinolone underwent macular threshold test using computerized visual field analyzer before and after 1, 2, 3, and 5 months of triamcinolone injection. Pre- and postinjection values of total defect depth, total threshold, and best-corrected visual acuity were compared and correlated. RESULTS: At the last follow-up, compared to baseline, visual acuity improved from 1.4+/-0.4 (logMAR, mean +/- standard deviation) to 1.0+/0.4 (p=0.01). Total defect depth tended to recover from 148+/-64 dB to 121+/-48 dB (p=0.12), and total threshold tended to increase from 241+/-87 dB to 271+/-68 dB (p=0.16), but these values did not reach significance. There was a significant correlation between baseline and 5 months postinjection values of total defect depth (rho=0.60, p=0.02), and of total threshold of light sensitivity (rho=0.55, p=0.04). CONCLUSIONS: Best-corrected visual acuity was found improved in patients with diabetic macular edema 5 months after triamcinolone injection. Improvement in central retinal sensitivity did not reach significant level at the last follow-up. Macular threshold test may be a valuable tool in the follow- up of patients with diffuse diabetic macular edema after intravitreal triamcinolone injection.