Hiroki Hatanaka

Epithelial-mesenchymal transition-like phenotypic changes of retinal pigment epithelium induced by TGF-β are prevented by PPAR-γ agonists.

PURPOSE Proliferative eye diseases, such as proliferative vitreoretinopathy and proliferative diabetic retinopathy, are caused partly by fibrotic change of retinal pigment epithelial cells (RPECs). The purpose of our study was to examine the effect of the peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist on the fibrotic change of primate RPECs. METHODS Monkey RPECs (MRPECs) isolated from a cynomolgus monkey eye were subcultured. To induce fibrotic change, MRPECs were cultured with TGF-β2 (3 ng/mL), and also cultured in the coexistence of TGF-β2 and the PPAR-γ agonist pioglitazone (30 μM). The phenotype of the cultured MRPECs was evaluated by phase contrast microscopy and immunocytochemical analysis. The phosphorylation of Smad2/Smad3 proteins was examined by Western blot analysis. RESULTS Primary MRPECs were cultured as a monolayer with a hexagonal cell shape, and positive expression of ZO-1, Na(+)/K(+)-ATPase, and RPE65 was confirmed. Cell morphology and the expression of these markers were maintained in the presence of pioglitazone, whereas the cells were elongated and the expression of these markers was reduced in its absence. Conversely, the expression of phalloidin, α-smooth muscle actin, and fibronectin was reduced in the presence of pioglitazone, whereas it was increased in the absence. Western blot assay demonstrated that phosphorylation of Smad2/Smad3 proteins was suppressed by pioglitazone. CONCLUSIONS The PPAR-γ agonist pioglitazone inhibited the fibrotic change of primary MRPECs through the suppression of TGF-β signaling. Pioglitazone might prove to be a clinically applicable and effective pharmaceutic treatment for proliferative eye diseases.

A study of host corneal endothelial cells after non-Descemet stripping automated endothelial keratoplasty.

Purpose: To determine the short-term fate of the host endothelium and Descemet membrane after non-Descemet stripping automated endothelial keratoplasty (nDSAEK). Methods: Eight unilateral DSAEK (n = 4) or nDSAEK (n = 4) surgeries were performed in the right eyes of 8 rabbits. Corneal transparency and thickness were followed-up by slit-lamp microscopy, and 2 weeks postoperatively, corneas were evaluated by immunohistochemistry and transmission electron microscopy. Results: Corneas remained clear after both DSAEK and nDSAEK. One week after DSAEK, the stroma-to-stroma surgical interface was identifiable as a zone of fibrotic tissue a few microns thick, whereas in the nDSAEK group, the recipient corneal endothelium and Descemet membrane were clearly visible at the graft–host interface. The retained endothelial cells were positive for Na+/K+-ATPase but assumed a markedly different morphology from healthy endothelial cells, with cell processes extending into the graft stroma or engulfing strands of irregularly dissected grafted stromal tissue where they occasionally appeared to compartmentalize the transplanted matrix and became detached from the underlying Descemet membrane. Conclusions: Host endothelial cells 2 weeks after nDSAEK express markers of pump function, but appear to be morphologically altered, occasionally detaching from the adjacent Descemet membrane, extending into the graft stroma or engulfing strands of the grafted stroma at the interface. The short-term persistence and subsequent phenotypical alternation of residual endothelial cells, aligned to structural changes to Descemet membrane, might influence graft adherence after nDSAEK.

Immunohistochemical Detection of Propionibacterium acnes in the Retinal Granulomas in Patients with Ocular Sarcoidosis

The etiology of sarcoidosis is still obscure; however, Mycobacteria and Propionibacterium acnes are considered the most implicated etiological agent for sarcoidosis. To investigate whether P. acnes is an etiological agent for sarcoid uveitis, we analyzed the frequency of P. acnes detected within the biopsied retinas from patients with ocular sarcoidosis by immunohistochemistry with a P. acnes-specific monoclonal antibody (PAB antibody). Eleven patients (12 eyes) with sarcoid uveitis were enrolled in this study. Eight patients with rhegmatogenous retinal detachment, two patients with non-sarcoid uveitis, and two patients with vitreoretinal lymphoma were enrolled as controls. In the sarcoidosis group, granulomas were mainly observed in the inner retinal layer filled with CD4+ cells and CD68+ cells, indicating the Th1 immune response. P. acnes, identified as round bodies that reacted with the PAB antibody, were present in 10/12 samples (83%) from 9/11 patients (82%) with sarcoidosis. These round bodies were scattered within the retinal granulomas mainly in the inner retinal layer. In the control group, no round bodies were detected. Our results suggested that P. acnes could be associated with sarcoid uveitis. We hypothesize that sarcoid granulomas may be formed by a Th1 immune response to P. acnes hematogenously transmitted to the retina.

Investigation into endothelial cell morphology following new methods of posterior corneal surgery [Abstract]

The main Autumn meeting of the BSMB was organized by Jelena Gavrilovic and held in the Thomas Paine Centre at the University of East Anglia (UEA) on 6th–7th September 2010. The meeting attracted 120 delegates and financial support was gratefully received from The Company of Biologists and the British Heart Foundation (Gold Sponsors), from the School of Biological Sciences at UEA, Roche and the International Journal of Experimental Pathology (Silver sponsors) and from AbCam, Exiqon, Lonza, Lavision Biotec, Promega, R&D Systems, Qiagen and Sartorius Stedim (Bronze sponsors). The programme featured eleven plenary lectures and eleven short talks from submitted abstracts as well as two poster sessions. The BSMB Young Investigator Lecture was given by Adam Byron. Mark Fidock from Pfizer also gave an informative short talk about ‘Careers in Big Pharma’. The meeting focused on the interplay between inflammation and matrix biology with expert speakers from the USA, Europe and the UK sharing new data emerging from cross-talk between these areas of interest. The organizer is very grateful to BSMB Treasurer, David Young, for his tremendous support as well as to Graham Riley, John Couchman, Jane Lohmann and other members of the BSMB committee for their input. Nicki Stead of UEA conference services also made an invaluable contribution both prior to and during the meeting. The International Journal of Experimental Pathology generously sponsored three prizes of £150 and the posters were judged by the Plenary Speakers. The prize recipients were Ching-Yan Chloe Yeung (Manchester, Richard Kelwick (UEA) and Thomas Duncan (Cardiff).