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· 2017
Abstract: Pathological neovascularization of the outer retina is the hallmark of neovascular age-related macular degeneration (nAMD). Building on our previous observations that semaphorin 3F (Sema3f) is expressed in the outer retina and demonstrates anti-angiogenic potential, we have investigated whether Sema3f can be used to protect against subretinal neovascularization in two mouse models. Both in the very low-density lipid-receptor knockout (Vldlr−/−) model of spontaneous subretinal neovascularization as well as in the mouse model of laser-induced choroidal neovascularization (CNV), we found protective effects of Sema3f against the formation of pathologic neovascularization. In the Vldlr−/− model, AAV-induced overexpression of Sema3f reduced the size of pathologic neovascularization by 56%. In the laser-induced CNV model, intravitreally injected Sema3f reduced pathologic neovascularization by 30%. Combined, these results provide the first evidence from two distinct in vivo models for a use of Sema3f in protecting the outer retina against subretinal neovascularization
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· 2019
Abstract: Objective: To describe vascular changes in different stages of Stargardt disease (STGD) via double swept-source optical coherence tomography angiography. Methods and analysis: Prospective, cross-sectional case-control study. Twenty-three patients (45 eyes) with ABCA4 mutations graded according to the Fishman STGD classification and 23 controls (23 eyes) were included. Two independent investigators quantified the foveal avascular zone (FAZ) in the superficial and deep capillary plexus (SCP/DCP) and the areas presenting rarefied flow and complete vascular atrophy in the outer retina to choriocapillaris (ORCC) and choriocapillaris (CC) slab. Results: The mean age at first diagnosis of STGD was 24.0 years (range 9-50) and 37.9 years (range 18-74) at the time of examination. Eleven patients were assigned to the Fishman STGD classification stage (S) 1, three to S2, eight to S3 and one to S4. The FAZ in SCP and DCP was increased in all stages compared with controls (p0.01). Areas with rarefied flow signal and vascular atrophy were detected in the ORCC and the CC layer and grew with increasing stage of disease (p0.01). The duration of disease correlated with the extent of the enlarged FAZ in the SCP/DCP and with the area of reduced flow in the ORCC and CC layer (p
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· 2018
Abstract: Purpose: Corneal vascularization significantly increases the risk for graft rejection after keratoplasty. Semaphorin 3F (Sema3F) is a known modulator of physiologic avascularity in the outer retina. The aim of this study was to investigate whether Sema3F is involved in maintaining corneal avascularity and can reduce the risk for corneal graft rejection. Methods: Corneal Sema3F expression was investigated using immunohistochemistry and qPCR in human and murine tissue. Pathologic invasion of blood and lymph vessels into corneal tissue was analyzed in the murine corneal suture and high-risk keratoplasty model. The anti-lymphangiogenic effects of Sema3F were further investigated using an in vitro spheroidal sprouting model with supernatant from isolated primary human corneal epithelial cells (hCECs). Results: Sema3F is constitutively expressed in human and murine corneal epithelium. In the corneal suture model, lymphangiogenesis was significantly suppressed by topical Sema3F treatment (P = 0.0003). In the murine high-risk keratoplasty model, pretreatment by topical Sema3F in the inflammation phase significantly promoted subsequent graft survival (P = 0.0006). In this model, both lymph- and blood angiogenesis were reduced (P 0.05). In vitro, hCEC supernatant had a direct anti-lymphangiogenic effect on human lymphatic endothelial cells (P 0.01). This effect was completely abolished by addition of anti-Sema3F antibodies.