Genetic cardiovascular risk factors and age-related macular degeneration.

PURPOSE: To investigate the association between genetic cardiovascular risk factors and exudative age-related macular degeneration (AMD) in a White Austrian population. METHODS: Seventy-five unrelated AMD patients and 75 unrelated healthy, sex- and age-matched control patients were genotyped for the following 19 single nucleotide polymorphisms (SNPs) in 14 different genes: blood coagulation factor V (FV) R506Q, factor II (prothrombin) G20210A and factor XIII (FXIII) V34L; 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T, A1298C; plasminogen activator inhibitor 1 (PAI-1) 4G/5G; endothelial protein C receptor (EPCR) 4600 A>G (A3 haplotype), 4678 G>C (A1 haplotype); apolipoprotein B (ApoB) R3500Q; apolipoprotein E (ApoE) E2/E3/E4; ß-fibrinogen -455 G>A; human platelet antigen 1 (HPA1) a/b; angiotensin-converting enzyme (ACE) I/D; endothelial nitric oxide synthase (eNOS) 786 T>C, 894 G>T; lymphotoxin alpha (LTA) 804 C>A and 9p21 rs10757278. Genotyping was carried out by polymerase chain reaction (PCR) followed by reverse hybridization (CVD StripAssays; ViennaLab Diagnostics, Vienna, Austria). RESULTS: No statistically significant association could be observed between AMD and the investigated genetic risk factors for cardiovascular disease (CVD). All factors seem to be uniformly distributed in the two groups of AMD patients and healthy controls. Two variables -ß-fibrinogen: -455 G>A (p = 0.0786) and apolipoprotein E4 (p = 0.0636) - were not as far from association as the others. CONCLUSION: Our data show that the 19 tested CVD risk markers do not play a significant role in AMD. ß-Fibrinogen and apolipoprotein E4 should be examined in a larger cohort.

Serum VEGF and CFH in exudative age-related macular degeneration.

PURPOSE: To determine serum vascular endothelial growth factor 165 (VEGF165) levels and the association of the complement factor H gene (CFH) Y402H polymorphism in patients with exudative age-related macular degeneration (AMD) in comparison to unaffected control subjects. METHODS: Sixty-six AMD patients and 66 healthy age- and gender-matched controls were included in this case-control study. The serum VEGF165 was assayed by ELISA (R&D). Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism analysis. Chi-squared tests were used regarding the polymorphism, a t-test regarding the VEGF-levels. RESULTS: Levels of serum VEGF165 were similar in both groups (p-value = 0.2112). Genotype frequency differed significantly between patients with exudative AMD and the healthy control group (p = 0.003136). The serum VEGF165 levels were similar irrespective of the presence of the CFH Y402H polymorphism (p = 0.4113) and independent of the specific genotype (p = 0.9634). CONCLUSION: In the present study, exudative AMD is not associated to serum VEGF165 levels; furthermore, our data does not establish a statistical link between VEGF165 and the CFH Y402H polymorphism.

Epidermal growth factor inhibits glycogen synthase kinase-3 (GSK-3) and beta-catenin transcription in cultured ARPE-19 cells.

BACKGROUND: Culture of retinal pigment epithelium (RPE) cells might be a future option in the therapy of various degenerative retinal diseases. However, the molecular changes which occur during in vitro expansion of RPE cells during culture are not fully elucidated. The aim of this study was to evaluate molecular changes in the RPE cell line ARPE-19 after stimulation with different growth factors. METHODS: Cultured ARPE-19 cells were stimulated for 72 hours with rh-EGF, rh-IGF-1, rh-VEGF or rh-bFGF, and transcriptional changes of the differentiation markers cytokeratin 18 and RPE65 and of the key molecules of the wnt pathway, beta-catenin, and glycogen synthase kinase-3 (GSK-3) were evaluated by real time RT-PCR. RESULTS: We found a significant decrease of cytokeratin 18 and RPE65 transcription after stimulation with rh-EGF (0.47 +/- 0.42 and 0.32 +/- 0.57-fold, respectively; p < 0.05). A significant reduction of beta-catenin and GSK-3 mRNA was found in ARPE-19 cells stimulated with rh-IGF-1 (0.61 +/- 0.25 and 0.52 +/- 0.02-fold, respectively) or rh-EGF (0.55 +/- 0.19 and 0.76 +/- 0.26-fold, respectively). No changes of beta-catenin mRNA were observed after stimulation with rh-VEGF or bFGF. CONCLUSION: Our data suggest an inhibition of the beta-catenin-pathway in ARPE-19 cells by IGF-1 and EGF, suggesting that ARPE-19 cell proliferation is, at least in part, driven by the beta-catenin pathway. Furthermore, induction of proliferation by EGF results in a loss of differentiation markers in these cells. Maintaining the RPE phenotype is still one of the main problems for RPE- transplantation.