Expression of Total Vascular Endothelial Growth Factor and the Anti-angiogenic VEGF 165 b Isoform in the Vitreous of Patients with Retinopathy of Prematurity.

BACKGROUND: This study was to examine the expression of total vascular endothelial growth factor (VEGF) and the anti-angiogenic VEGF 165 b isoform in the vitreous body of retinopathy of prematurity (ROP) patients, and to further study the role of the VEGF splicing in the development of ROP. METHODS: This was a prospective clinical laboratory investigation study. All patients enrolled received standard ophthalmic examination with stage 4 ROP that required vitrectomy to collect the vitreous samples. The control samples were from congenital cataract patients. The expression of total VEGF and the anti-angiogenic VEGF 165 b were measured by enzyme-linked immunosorbent assay. Results were analyzed statistically using nonparametric tests. RESULTS: The total VEGF level was markedly elevated in ROP samples while VEGF 165 b was markedly decreased compared to control group. The relative protein expression level of VEGF 165 b isoform was significantly decreased in ROP patients which were correlated with the ischemia-induced neovascularization. CONCLUSIONS: There was a switch of VEGF splicing from anti-angiogenic to pro-angiogenic family in ROP patients. A specific inhibitor that more selectively targets VEGF 165 and controls the VEGF splicing between pro- and anti-angiogenic families might be a more effective therapy for ROP.

Association of complement factor H gene polymorphisms with age-related macular egeneration susceptibility.

OBJECTIVE: This study was aimed to confirm whether I62V and Y402H polymorphisms of complement factor H (CFH) were risk factors for age-related macular degeneration (AMD). METHOD: 109 AMD patients and 165 AMD-free controls were enrolled in the study. The I62V and Y402H polymorphisms were analyzed by polymerase chain reaction-restriction fragment length of polymorphism (PCR-RFLP). Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by the X2 test to assess the relationship of I62V and Y402H polymorphisms with AMD risk. Analysis of haplotype and stratification by age and smoking status was conducted as well. RESULTS: AA genotype and A allele of I62V polymorphism was significantly associated with increased risk for AMD (OR=3.75, 95% CI=1.70-8.30; OR=1.64, 95% CI=1.14-2.36). For Y402H polymorphism, CT genotype showed strong effects on the occurrence of AMD (OR=2.10, 95% CI=1.04-4.27). Moreover, C allele was also a risk factor for AMD (OR=1.95, 95% CI=1.02-3.72). The haplotypes analysis suggested that the risk for AT haplotype carriers was high, compared with GT haplotype (OR=3.91, 95% CI=2.58-5.94). In addition, we found that smoking status could affect the genotype distribution of Y402H polymorphism (P<0.05). CONCLUSIONS: Our results revealed that CFH polymorphisms I62V and Y402H might be associated with the susceptibility to AMD in Chinese population.

Inhibition of neovascularization and expression shift of pro-/anti-angiogenic vascular endothelial growth factor isoforms after intravitreal bevacizumab injection in oxygen-induced-retinopathy mouse model.

BACKGROUND: Retinopathy of prematurity (ROP) has become one of the leading causes of visual loss in children. Vascular endothelial growth factor A (VEGF-A) is the principal stimulator of angiogenesis. VEGF was differentially spliced from exon 8 to exons 8a and 8b to form two families: the pro-angiogenic VEGFxxx family and the anti-angiogenic VEGFxxxb family. Previous research has shown variable effeteness of bevacizumab in inhibiting retinal neovascularization in ROP. This study aimed to investigate whether the effectiveness of this inhibition depends on the relative ratio of the two VEGF isoforms. METHODS: Intravitreal bevacizumab injection (IVB) was performed in the oxygen-induced-retinopathy (OIR) mice on postnatal day 12 (P12) (intravitreal phosphate buffered saline (PBS) injection as control). The Evans blue perfused retina were used to test the retinal neovascularization-leakage (NVL) area and non-perfusion (NP) area. RESULTS: The retinal NVL and NP area in the IVB group were significantly smaller than the intravitreal PBS injection group (IVP group). On P17, the protein level of total VEGF isoforms was significantly inhibited compared to IVP group (P < 0.05) while VEGF(165)b isoform was slight reduced (P > 0.05). The switch from pro-angiogenic isoforms to anti-angiogenic isoforms after IVB could be found. The relative protein expression of VEGF(165)b isoform was significantly higher in IVB group than in IVP group (P < 0.05) on P17 which was correlated with the reduced ischemia-induced angiogenesis in OIR mice after IVB. CONCLUSIONS: The anti-angiogenic effectiveness might depend on the relative high expression of VEGF(165)b after intravitreal bevacizumab injection. Anti-angiogenic therapy is a more effective therapy for ROP.