PURPOSE. Epithelial-mesenchymal transition (EMT) in retinal pigment epithelial (RPE) cells is related to the pathogenesis of subretinal fibrosis such as that associated with macular degeneration. The role of myocardin-related transcription factor A (MRTF-A) in EMT of RPE cells and subretinal fibrosis was investigated.METHODS. The migratory activity of human RPE-1 cells in culture was evaluated using a scratch assay. The subcellular distribution of MRTF-A in RPE-1 cells, as well as the extent of subretinal fibrosis in a mouse model, were determined by immunofluorescence analysis. Expression of a-smooth muscle actin (a-SMA), collagen type I (COL1), connective tissue growth factor (CTGF), and paxillin was examined by immunoblot analysis or reverse transcription and quantitative polymerase chain reaction analysis, whereas that of pro-matrix metalloproteinase-2 (MMP-2) was assessed by gelatin zymography.RESULTS. The MRTF-A signaling inhibitor CCG-1423 suppressed RPE-1 cell migration in a concentration-dependent manner. Transforming growth factor-beta (TGF-b2) induced MRTF-A translocation from the cytoplasm to the nucleus of RPE-1 cells, and this effect was attenuated by CCG-1423. TGF-b2 up-regulated the abundance of a-SMA, paxillin, and pro-MMP-2 proteins as well as the amounts of a-SMA, COL1, and CTGF mRNAs in a manner sensitive to inhibition by CCG-1423. Finally, intravitreal injection of CCG-1423 markedly attenuated the development of subretinal fibrosis induced by photocoagulation in vivo. CONCLUSIONS.Our results implicate MRTF-A in EMT of RPE cells and in the development of subretinal fibrosis in vivo, suggesting that MRTF-A is a potential therapeutic target for retinal diseases characterized by subretinal fibrosis.

Retinitis pigmentosa (RP) and macular dystrophy (MD) are characterized by gradual photoreceptor death in the retina and are often associated with genetic mutations including those in the Prominin-1 (Prom1) gene. Prom1-knockout (KO) mice recapitulate key features of these diseases including light-dependent retinal degeneration and constriction of retinal blood vessels. The mechanisms underlying such degeneration have remained unclear, however. We here analysed early events associated with retinal degeneration in Prom1-KO mice. We found that photoreceptor cell death and glial cell activation occur between 2 and 3 weeks after birth. Whereas gene expression was not affected at 2 weeks, the expression of several genes was altered at 3 weeks in the Prom1-KO retina, with the expression of that for Endothelin-2 (Edn2) being markedly up-regulated. Expression of Edn2 was also induced by light stimulation in Prom1-KO mice reared in the dark. Treatment with endothelin receptor antagonists attenuated photoreceptor cell death, gliosis, and retinal vessel stenosis in Prom1-KO mice. Our findings thus reveal early manifestations of retinal degeneration in a model of RP/MD and suggest potential therapeutic agents for these diseases.

We previously showed that dietary omega (ω)–3 long-chain polyunsaturated fatty acids (LCPUFAs) suppress inflammation in mice with experimental autoimmune uveitis (EAU). We have now investigated the role of antigen presenting cells (APCs) in this action of ω-3 LCPUFAs. C57BL/6 mice were fed a diet supplemented with ω-3 or ω-6 LCPUFAs for 2 weeks, after which splenocytes were isolated from the mice and cocultured with CD4 + T cells isolated from mice with EAU induced by injection of a human interphotoreceptor retinoid-binding protein peptide together with complete Freund’s adjuvant. The proliferation of and production of interferon-γ and interleukin-17 by T cells from EAU mice in vitro were attenuated in the presence of splenocytes from ω-3 LCPUFA–fed mice as compared with those from mice fed ω-6 LCPUFAs. Splenocyte fractionation by magnetic-activated cell sorting revealed that, among APCs, dendritic cells (DCs) were the target of ω-3 LCPUFAs. Adoptive transfer of DCs from mice fed ω-3 LCPUFAs attenuated disease progression in EAU mice as well as the production of pro-inflammatory cytokines by T cells isolated from these latter animals. The proliferation of T cells from control Balb/c mice was also attenuated in the presence of DCs from ω-3 LCPUFA–fed mice as compared with those from ω-6 LCPUFA–fed mice. Furthermore, T cell proliferation in such a mixed lymphocyte reaction was inhibited by prior exposure of DCs from mice fed an ω-6 LCPUFA diet to ω-3 LCPUFAs in vitro. Our results thus suggest that DCs mediate the anti-inflammatory action of dietary ω-3 LCPUFAs in EAU.

Epithelial–mesenchymal transition (EMT) in retinal pigment epithelial (RPE) cells plays a key role in proliferative retinal diseases such as age-related macular degeneration by contributing to subretinal fibrosis. To investigate the potential role of retinoic acid receptor-α (RAR-α) signaling in this process, we have now examined the effects of the RAR-α agonist Am580 on EMT induced by transforming growth factor-β2 (TGF-β2) in primary mouse RPE cells cultured in a three-dimensional type I collagen gel as well as on subretinal fibrosis in a mouse model. We found that Am580 inhibited TGF-β2-induced collagen gel contraction mediated by RPE cells. It also attenuated the TGF-β2-induced expression of the mesenchymal markers α-smooth muscle actin, fibronectin, and collagen type I; production of pro-matrix metalloproteinase 2 and interleukin-6; expression of the focal adhesion protein paxillin; and phosphorylation of SMAD2 in the cultured RPE cells. Finally, immunofluorescence analysis showed that Am580 suppressed both the TGF-β2-induced translocation of myocardin-related transcription factor-A (MRTF-A) from the cytoplasm to the nucleus of cultured RPE cells as well as subretinal fibrosis triggered by laser-induced photocoagulation in a mouse model. Our observations thus suggest that RAR-α signaling inhibits EMT in RPE cells and might attenuate the development of fibrosis associated with proliferative retinal diseases.

Purpose To investigate the influence of EDOF IOLs, TECNIS Symfony ® (Johnson & Johnson Surgical Vision, Inc.), on visual field sensitivity and to compare the IOLs with other kinds of IOLs. Methods The subjects included the normal fellow eyes of patients who underwent the Humphrey Field Analyzer (HFA) 30–2 with Swedish Interactive Threshold Algorithm Fast within 6 months after cataract due to glaucoma or suspected glaucoma. Each parameter of HFA was compared among eyes implanted with TENIS Symfony ® (EDOF group), diffractive bifocal IOLs (bifocal group), and monofocal IOLs (monofocal group). Results The total of 76 eyes, including 24 eyes in the EDOF group, 26 eyes in the bifocal group, and 26 eyes in the monofocal group, were included in this study. Mean deviation (MD) of HFA was -0.24±0.58 dB in the EDOF group, -1.38±0.58 dB in the bifocal group, and 0.02±0.44 dB in the monofocal group. Foveal threshold (FT) of HFA was 35.8±1.6 dB in the EDOF group, 33.6±1.7 dB in the bifocal group, and 36.6±1.4 dB in the monofocal group. In both MD and FT, there was significant difference between the bifocal group and the others (p<0.001). There was no difference between the EDOF group and the monofocal group. Moreover, there was no significant difference between the three groups about pattern standard deviation (PSD) of HFA. Conclusion TECNIS Symfony ® may have little influence on visual field sensitivity, whereas diffractive bifocal IOLs decrease visual field sensitivity.