No association between complement factor H gene polymorphism and exudative age-related macular degeneration in Japanese.

Age-related macular degeneration (ARMD) is the leading cause of blindness in the elderly population not only Western but also Asian industrial countries. In Caucasian, a polymorphism of the complement factor H gene (CFH), the C allele of rs1061170 (Y402H), was established as the first strong genetic factor for excursively exudative type of ARMD. In this study, we performed an extensive sequencing of the 22 exons in the CFH gene by recruiting 146 exudative ARMD patients and 105 normal controls of Japanese origin and identified 61 polymorphisms. We found that the frequency of the C allele of rs1061170 (Y402H) is much lower (0.04) in Japanese controls than in Caucasians (0.45). No case disease susceptibility to exudative ARMD was noted for rs1061170 (Y402H) (chi (2) = 3.19, P (corr) = 0.423), or other 12 single nucleotide polymorphisms (SNPs) whose frequency is greater than 0.05. When haplotypes were inferred for 13 SNPs (these 12 SNPs with a frequency greater than 0.05 and rs1061170), three haplotypes whose pattern was similar to those in Caucasians were identified but with substantial difference in frequency. Again we failed to identify genetic association between Japanese exudative ARMD and any of the haplotypes including the J1 haplotype which was shown to be susceptible to ARMD in Caucasians (chi (2 )=( )3.92, P (corr) = 0.157). CFH does not appear to be a primary hereditary contributor to ARMD in Japanese. The absence of CFH contribution to ARMD in Japanese may correlate with the findings in ethnic differences of ARMD phenotypes.

Apolipoprotein E polymorphisms in Japanese patients with polypoidal choroidal vasculopathy and exudative age-related macular degeneration.

PURPOSE: To study the genotypes, allelic frequencies, and polymorphisms of apolipoprotein E (Apo E) in unrelated Japanese patients with polypoidal choroidal vasculopathy (PCV) or exudative age-related macular degeneration (AMD) and control subjects without macular degeneration. DESIGN: Cross-sectional study. METHODS: Blood samples from 225 subjects older than 50 years were used. The 225 subjects included 58 patients with PCV, 85 with AMD, and 82 without macular degeneration. Coding exons of the Apo E gene were amplified by polymerase chain reaction, and the DNA sequences were determined by direct sequencing with an automated sequencer. RESULTS: Apo E epsilon3/epsilon3 was the most frequent genotype with a prevalence of 79.3% in PCV patients, 76.5% in AMD patients, and 67.1% in the control subjects. However, the differences in the percentages were not statistically significant among the three groups. The most frequently found allele in the three groups was epsilon3. Patients with PCV and AMD were less likely to have epsilon2 and epsilon4 than the control subjects, but the differences were not statistically significant. Five minor Apo E single nucleotide polymorphisms, including epsilon5 and epsilon7, were found. CONCLUSION: Japanese patients with PCV and AMD were less likely to have epsilon2 and epsilon4 polymorphisms, but the differences from the normals were not statistically significant for the Apo E genotypes and allelic frequencies.

Pathological features of surgically excised polypoidal choroidal vasculopathy membranes.

The histopathological features are reported of surgically excised specimens from five patients with polypoidal choroidal vasculopathy, which had been diagnosed by indocyanine green angiography. On stereomicroscopy, four of the five cases demonstrated large choroidal arterioles with an inner elastic layer. Disruption of the inner elastic layer and arteriosclerotic changes of the vessels were identified by light microscopy. Transmission electron microscopy demonstrated increased deposition of basement membrane-like material, together with collagen fibres, in the arteriolar walls. This study indicates that large choroidal arterioles and venules can be found in excised specimens from patients with polypoidal choroidal vasculopathy and arteriosclerosis is an important pathological feature.

Differential temporal and spatial expression of immediate early genes in retinal neurons after ischemia-reperfusion injury.

PURPOSE: To investigate genes that are up- and downregulated in rat retinal ischemia-reperfusion injury systematically by using an oligonucleotide microarray system and to determine temporal and spatial expression changes of some genes that showed upregulation in the analysis. METHODS: Retinal ischemia was induced in rats by increasing intraocular pressure to 110 mm Hg for 1 hour. Gene expression at 12 hours after reperfusion was compared with that in the control retina by using oligonucleotide microarrays that display a total of 8800 genes and expressed sequence tags (ESTs). Temporal and spatial expression changes of immediate early genes and cell-cycle-related genes were studied by using real-time polymerase chain reaction (PCR) and immunohistochemical methods. RESULTS: At 12 hours after reperfusion, 135 genes and ESTs were found to be up- or downregulated. The upregulated genes were classified into seven groups: (1) immediate early genes; (2) cell-cycle-related genes; (3) stress-responsive protein genes; (4) cell-signaling protein genes; (5) cell-adhesion and cell surface protein genes; (6) genes for translation and protein turnover; and (7) genes for metabolism. Real-time PCR analyses showed peaks of Fra-1 expression at 6 hours after reperfusion, whereas those for c-Jun, Jun B, and cyclin D1 were at 24 hours. Fra-1 and Jun B immunoreactivities were found in Müller cells, whereas c-Jun and cyclin D1 immunoreactivities were found in apoptotic retinal neurons. CONCLUSIONS: Gene expression changes after a retinal ischemia-reperfusion injury were profiled by using an oligonucleotide microarray system. Seven groups of genes were found to be upregulated by the injury. Among the immediate early genes, Fra-1 and Jun B immunoreactivities were found in Müller cells whereas c-Jun and cyclin D1 immunoreactivities were found in apoptotic retinal neurons.

Polypoidal choroidal vasculopathy with large vascular network.

PURPOSE: To report characteristics of polypoidal choroidal vasculopathy (PCV) of large vascular networks that expand across the retinal vascular arcade. METHODS: Among 60 consecutive eyes diagnosed as having PCV by fluorescein and indocyanine green (ICG) angiography, 12 eyes (9 patients) showed large lesions. The clinical and angiographic features of these 12 eyes were studied retrospectively. RESULTS: Cases of large PCV typically showed dilated network vessels, which spread radially, and multiple polypoidal dilations at the end of the network vessels. Most of the polypoidal dilations formed clusters resembling bunches of grapes and caused large serous and/or hemorrhagic pigment epithelial detachments (PEDs). Among the 12 eyes, 5 showed rapid expansion of the lesions and became large PCVs within 3-24 months. In these eyes, ICG angiography revealed mesh-like choroidal vessels beneath the retinal pigment epithelium. CONCLUSION: PCV with a large vascular network that expands across the vascular arcade is not uncommon. Some of these cases seems to have characteristics of choroidal neovascularization rather than choroidal vasculopathy. It is not easy to distinguish such cases from exudative age-related macular degeneration even though they showed typical findings of PCV on ICG angiography.

Expression and neuroprotective effect of hepatocyte growth factor in retinal ischemia-reperfusion injury.

PURPOSE: To investigate the expression and possible neuroprotective effects of hepatocyte growth factor (HGF) in a rat model of retinal ischemia-reperfusion injury. METHODS: Retinal ischemia was induced in adult male Sprague-Dawley rats by raising the intraocular pressure to 110 mm Hg for 45 minutes. To study expression of HGF and its receptor c-Met, reverse transcription-polymerase chain reaction (RT-PCR), Western blot analysis, and immunohistochemical staining were performed on eyes enucleated at 6, 12, 24, 48, and 96 hours after reperfusion. To examine the neuroprotective effects of HGF, recombinant human (rh)HGF (1, 6, and 12 microg in 2 microL PBS) or vehicle was administered intravitreally 1 minute after reperfusion, and the eyes were enucleated at 6, 12, 24, 48, and 96 hours and 28 days after reperfusion. The retinal damage was assessed by electroretinogram (ERG) recordings, by measuring the inner retinal thickness, and by counting the number of TUNEL-positive cells in each retinal layer. RESULTS: RT-PCR and Western blot analyses showed upregulation of HGF and c-Met-HGF receptor mRNA at 6, 12, 24, and 48 hours after reperfusion, compared with the normal rat retina. Immunohistochemically, expression of HGF was found in the retinal pigment epithelial cells at 6 hours after reperfusion and in some cells in the ganglion cell layer and inner nuclear layer at 24 hours after reperfusion. The amplitudes of the ERG b-wave and oscillatory potentials were significantly larger in the eyes treated with 6 and 12 microg rhHGF than in those of vehicle-treated control rats (P < 0.01). On day 28, the thicknesses of the inner retina of vehicle-treated rats and that of 6-microg rhHGF-treated rats were 54.4 +/- 6.12 (mean +/- SD, n = 9) and 71.5 +/- 9.81 microm (n = 8), respectively (P < 0.01). The number of TUNEL-positive cells at 6, 12, 24, and 48 hours after reperfusion was decreased significantly by treatment with 6 microg rhHGF, compared with those in the control rats (P < 0.01). CONCLUSIONS: Upregulation of HGF in the retina may play a role in retinal ischemia-reperfusion injury. Intravitreal injection of rhHGF is neuroprotective against the injury.