Hiroaki Bessho

Tea Catechin Suppresses Adipocyte Differentiation Accompanied by Down-regulation of PPARγ2 and C/EBPα in 3T3-L1 Cells

Obesity is a serious health problem, and its prevention is promoted through life style including diet and exercise. In this study, we investigated the suppressive effects of tea catechin on the differentiation of 3T3-L1 preadipocytes to adipocytes. (−)-Catechin 3-gallate (CG), (−)-epigallocatechin (EGC), (−)-epicatechin 3-gallate, and (−)-epigallocatechin 3-gallate at 5 μM suppressed intracellular lipid accumulation. The suppressive effects of CG and EGC were stronger than the others, and CG and EGC also suppressed the activity of glycerol-3-phosphate dehydrogenase as a differentiation marker. These catechins inhibited the expression of peroxisome proliferator-activated receptor (PPAR) γ2 and CCAAT/enhancer-binding protein (C/EBP) α, both of which act as key transcription factors at an early stage of differentiation, followed by the expression of glucose transporter (GLUT) 4 at a later stage. In addition, the catechins did not affect the phosphorylation status of the insulin signal pathway. Thus, catechin suppressed adipocyte differentiation accompanied by the down-regulation of PPARγ2, C/EBPα, and GLUT4. These results suggest that tea catechin prevents obesity through the suppression of adipocyte differentiation.

SOD2 gene polymorphisms in neovascular age-related macular degeneration and polypoidal choroidal vasculopathy

PURPOSE To study and reveal genetic variation in the elastin gene (ELN) that may be associated with neovascular age-related macular degeneration (AMD) and/or polypoidal choroidal vasculopathy (PCV). Eyes with neovascular AMD and PCV exhibit substantially different structural alterations of the elastic layer in the Bruchs membrane. The hypothesis for the present study was that ELN polymorphisms may play a role in the development of neovascular AMD and PCV and that genetic differences in ELN between these two phenotypes may be a reason for the histopathologic differences. To test these hypotheses, ELN was screened for genetic variation in a Japanese case-control dataset. METHODS Two hundred eighty-five subjects were enrolled: 78 with neovascular AMD, 103 with PCV, and 104 control. We genotyped five tagged single nucleotide polymorphisms (SNPs) in ELN, and allele, genotype, and haplotype frequency distributions among neovascular AMD, PCV, and control subjects were compared by chi(2) tests. RESULTS A common ELN variant was significantly associated with susceptibility to PCV. The age- and sex-adjusted odds ratio was 7.56 for individuals homozygous for the risk allele compared with those carrying no more than one copy of the risk allele. Significantly different distributions were found in allele and haplotype frequencies between neovascular AMD and PCV in this region, but no particular ELN SNPs or haplotypes were significantly associated with neovascular AMD. CONCLUSIONS The findings implicate ELN as a susceptibility gene for PCV, and suggest that a different pathogenic process may be involved in the phenotypic expression of neovascular AMD and PCV.

Complement Factor H Y402H Variant and Risk of Age-Related Macular Degeneration in Asians: A Systematic Review and Meta-Analysis

PURPOSE To investigate whether the Y402H variant in the complement factor H gene is associated with age-related macular degeneration (AMD) in Asian populations. DESIGN Meta-analysis of previous publications. PARTICIPANTS Case-control groups of subjects with AMD and controls from 13 association studies. METHODS We performed a meta-analysis of the association between Y402H and AMD in Asian populations using data available from 13 case-control studies involving 3973 subjects. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using fixed- and random-effects models. The Q-statistic test was used to assess heterogeneity, and Eggers test was used to evaluate publication bias. Sensitivity analysis, cumulative meta-analysis, and meta-regression analysis were also performed. MAIN OUTCOME MEASURES Allele and genotype frequencies of the Y402H variant. RESULTS The Y402H variant showed a significant summary OR of 1.97 (95% CI, 1.54-2.52; P<0.001; allelic contrast model) per allele. Possession of at least 1 copy of the C allele increased the disease risk by 1.97-fold (95% CI, 1.63-2.39; P<0.001; dominant model) and accounted for 8.8% of the attributable risk of AMD in Asian populations. Sensitivity analysis indicated the robustness of our findings, and evidence of publication bias was not observed in our meta-analysis. Meta-regression analysis indicated no significant effect of baseline study characteristics on the summary effect size. Cumulative meta-analysis revealed that the summary ORs were stable and the 95% CIs narrowed with the accumulation of data over time. CONCLUSIONS Our analysis provides substantial evidence that the Y402H variant is significantly associated with AMD in Asian populations. Our results expand the number of confirmed AMD susceptibility loci for Asians populations, which provide a better understanding of the genetic architecture underlying disease susceptibility and may advance the potential for preclinical prediction in future genetic tests by a combined evaluation of inherited susceptibility with previously established loci.

Common Variants in the Complement Factor H Gene Confer Genetic Susceptibility to Central Serous Chorioretinopathy

PURPOSE To investigate whether complement factor H (CFH) gene DNA variants are associated with central serous chorioretinopathy (CSCR). DESIGN Cross-sectional study. PARTICIPANTS A case-control group of 140 CSCR subjects and 2 different control groups: 934 population-based controls and 335 hospital-based controls. METHODS Five single-nucleotide polymorphisms (SNPs) in CFH (rs3753394, rs800292, rs2284664, rs1329428, and rs106548) were evaluated for association with CSCR in 2 separate association analyses comparing CSCR subjects with 2 different control groups. Genotyping was performed using TaqMan technology (Applied Biosystems, Foster City, CA). MAIN OUTCOME MEASURES Allele and haplotype frequencies of the 5 variants in the CFH region. RESULTS Highly statistically significant associations with CSCR were found for the 5 SNPs. The strongest association was observed with rs1329428 (allelic P = 6.44×10(-6); odds ratio, 1.79; 95% confidence interval [CI], 1.39-2.31, cases vs. population-based controls), which accounted for 35.5% of the population-attributable fraction for CSCR. Consistent with the analysis, rs1329428 showed the strongest disease association (allelic P = 1.00×10(-5); odds ratio, 1.89; 95% CI, 1.42-2.50) in comparing cases with hospital-based controls. The second most strongly associated SNP, rs1065489, was correlated highly with the most strongly associated SNP, rs1329428 (r(2) = 0.77), and their effects could not be distinguished statistically from each other. A conditional logistic regression analysis revealed that the 2 highly correlated SNPs, rs1329428 and rs1065489, account for the association signals detected at the CFH locus. CONCLUSIONS We identified a novel association between CSCR and common CFH polymorphisms. Our findings support the involvement of CFH in the pathogenesis of CSCR; exploration of the role of CFH could yield important insights into the biological mechanisms underlying CSCR. Our identification of common CFH variants as susceptibility elements for CSCR will open new avenues for research, leading to a better understanding of CSCR pathogenesis and ultimately to the development of improved therapeutic approaches.

Natural course and funduscopic findings of polypoidal choroidal vasculopathy in a Japanese population over 1 year of follow-up.

Purpose: To evaluate the natural course and possible funduscopic risk factors for polypoidal choroidal vasculopathy in a Japanese population. Methods: The records of 42 eyes from 41 patients (27 men and 14 women) diagnosed as having polypoidal choroidal vasculopathy located in the macula between November 1999 and October 2005 were retrospectively reviewed. The funduscopic findings at the first visit were evaluated. The changes in the best-corrected visual acuity (BCVA) from the baseline to 12 months were analyzed. The lesion types (clustered vs. nonclustered) found on indocyanine green angiography were compared for changes in the BCVA from the initial visit to 12 months. Results: The mean age of the subjects was 73.8 ± 8.0 years. The mean logarithm of the minimum angle of resolution (LogMAR) BCVA was 0.48 ± 4.0 at baseline and deteriorated to 0.75 ± 5.7 after 12 months, which was statistically significant (P = 0.00075). The mean LogMAR BCVA in the patients showing “nonclustered” polypoidal choroidal lesions on indocyanine green angiography was maintained for 12 months, while that of the “clustered” group decreased significantly during the same period (P = 0.0014). Conclusion: Polypoidal choroidal vasculopathy did not show a favorable outcome in terms of the mean BCVA 12 months after the initial visit. The clustered polypoidal choroidal lesions on indocyanine green angiography may be related to poor prognosis of polypoidal choroidal vasculopathy over the natural course.

Additional evidence to support the role of a common variant near the complement factor I gene in susceptibility to age-related macular degeneration.

In 2008, Fagerness et al1 provided new evidence of an association between common variants on chromosome 4q25 harboring the complement factor I gene and advanced age-related macular degeneration (AMD), a leading cause of irreversible blindness worldwide. Based on a high-density genotyping analysis and using a large sample (1228 case subjects and 825 control subjects of European descent), Fagerness et al1 found the most significant evidence for association at a single-nucleotide polymorphism (SNP) located 2781 bp upstream of the 3′ UTR of the complement factor I gene (rs10033900). Until now, only one replication study has been done for this association in a Caucasian population of European ancestry, providing further support of this regions importance for AMD.2 However, its relevance to other ethnic populations remains to be clarified, and evaluation of this association in cohorts of non-European ancestry is desired to establish the consistency and generalizability of the original association. We conducted a case–control association study to validate the reported association of the key variant, rs10033900, in a Japanese population.

Early Responses to Intravitreal Ranibizumab in Typical Neovascular Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy

Purpose. To evaluate the early response to intravitreal ranibizumab (IVR) in two different phenotypes of age-related macular degenerations (AMD): typical neovascular AMD (tAMD) and polypoidal choroidal vasculopathy (PCV). Methods. Sixty eyes from 60 patients (tAMD 28, PCV 32 eyes) were recruited. Three consecutive IVR treatments (0.5 mg) were performed every month. Change in the best-corrected visual acuity (BCVA) and central retinal thickness (CRT) was then compared between the tAMD and PCV groups. Results. The mean BCVA logMAR was significantly improved at month 1 and month 3 after the initial IVR in the tAMD group, but there was no change in the PCV group. Both phenotypes showed significant improvements in the CRT during the 3 months after the initial IVR. There were no significant differences in the improvements of the CRT in the tAMD versus the PCV group. In the stepwise analysis, a worse pretreatment BCVA and tAMD lesions were significantly beneficial for a greater improvement of BCVA at 3 months after the initial IVR. Conclusions. The phenotype of tAMD showed a significantly better early response to IVR than PCV in terms of BCVA improvement.

A prospective multicenter study on genome wide associations to ranibizumab treatment outcome for age-related macular degeneration

We conducted a genome-wide association study (GWAS) on the outcome of anti-VEGF treatment for exudative age-related macular degeneration (AMD) in a prospective cohort. Four hundred and sixty-one treatment-naïve AMD patients were recruited at 13 clinical centers and all patients were treated with 3 monthly injections of ranibizumab followed by pro re nata regimen treatment for one year. Genomic DNA was collected from all patients for a 2-stage GWAS on achieving dry macula after the initial treatment, the requirement for an additional treatment, and visual acuity changes during the 12-month observation period. In addition, we evaluated 9 single-nucleotide polymorphisms (SNPs) in 8 previously reported AMD-related genes for their associations with treatment outcome. The discovery stage with 256 patients evaluated 8,480,849 SNPs, but no SNPs showed genome-wide level significance in association with treatment outcomes. Although SNPs with P-values of <5 × 10−6 were evaluated in replication samples of 205 patients, no SNP was significantly associated with treatment outcomes. Among AMD-susceptibility genes, rs10490924 in ARMS2/HTRA1 was significantly associated with additional treatment requirement in the discovery stage (P = 0.0023), and pooled analysis with the replication stage further confirmed this association (P = 0.0013). ARMS2/HTRA1 polymorphism might be able to predict the frequency of injection after initial ranibizumab treatment.

Positive Association of Complement Factor H Gene Variants with the Effect of Photodynamic Therapy in Polypoidal Choroidal Vasculopathy

Purpose: To clarify the association of complement factor H (CFH) gene polymorphisms with the effects of photodynamic therapy (PDT) in polypoidal choroidal vasculopathy (PCV). Methods: Ninety-three PCV subjects treated with PDT were recruited. Patients who showed anatomical success after the treatments with a single or two consecutive PDT sessions were classified as PDT responders. All others were classified as non-PDT responders. Three single nucleotide polymorphisms (SNPs), rs800292 (I62V), rs1061170 (Y402H) and rs1410996 were genotyped using the TaqMan assay. Results: The genotype and allelic frequency of rs1061170 (Y402H) and rs1410996 were significantly different between PDT responders and non-responders. In these SNPs, the risk alleles for PCV prevalence were beneficial for PDT response. In the time course analysis, the cases with C/C genotype in rs1410996 showed a significant increase of mean visual acuity at 6 and 12 months after the first PDT. Conclusions: The coding variants in CFH may be associated with the effects of PDT in PCV.