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Progression of Pro23His Retinopathy in a Miniature Swine Model of Retinitis Pigmentosa
摘要： Purpose: We characterize the progression of retinopathy in Filial 1 (F1) progeny of a transgenic (Tg) founder miniswine exhibiting severe Pro23His (P23H) retinopathy. Methods: The F1 TgP23H miniswine progeny were created by crossing TgP23H founder miniswine 53-1 with wild type (WT) inbred miniature swine. Scotopic (rod-driven) and photopic (cone-driven) retinal functions were evaluated in F1 TgP23H and WT littermates using full field electroretinograms (ffERGs) at 1, 2, 3, 6, 9, 12, and 18 months of age, as well as the Tg founder miniswine at 6 years of age. Miniswine were euthanized and their retinas processed for morphologic evaluation at the light and electron microscopic level. Retinal morphology of a 36-month-old Tg miniswine also was examined. Results: Wild type littermates reached mature scotopic and photopic retinal function by 3 months, while TgP23H miniswine showed abnormal scotopic ffERGs at the earliest time point, 1 month, and depressed photopic ffERGs after 2 months. Rod and cone photoreceptors (PR) exhibited morphologic abnormalities and dropout from the outer nuclear layer at 1 month, with only a monolayer of cone PR somata remaining after 2 months. The retinas showed progressive neural remodeling of the outer retina that included dendritic retraction of rod bipolar cells and glial seal formation by M¨uller cells. The TgP23H founder miniswine showed cone PR with relatively intact morphology exclusive to the area centralis. Conclusions: The F1 Tg miniswine and the TgP23H founder miniswine exhibit similar retinopathy. Translational Relevance: TgP23H miniswine are a useful large-eye model to study pathogenesis and preservation cone PRs in humans with retinitis pigmentosa.
关键词： retinal degeneration,swine,retinitis pigmentosa
更新于2025-09-04 15:30:14
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Medium- to long-term survival and functional examination of human iPSC-derived retinas in rat and primate models of retinal degeneration
摘要： Background: We have previously reported that xeno-transplanted human ESC-derived retinas are able to mature in the immunodeficient retinal degeneration rodent models, similar to allo-transplantations using mouse iPSC-derived retina. The photoreceptors in the latter developed outer segments and formed synapses with host bipolar cells, driving light responses of host retinal ganglion cells. In view of clinical application, here we further confirmed the competency of human iPSC-derived retina (hiPSC-retina) to mature in the degenerated retinas of rat and monkey models. Methods: Human iPSC-retinas were transplanted in rhodopsin mutant SD-Foxn1 Tg(S334ter)3LavRrrc nude rats and two monkeys with laser-induced photoreceptor degeneration. Graft maturation was studied by immunohistochemistry and its function was examined by multi-electrode array (MEA) recording in rat retinas and visually-guided saccade (VGS) in a monkey. Findings: A substantial amount of mature photoreceptors in hiPSC-retina graft survived well in the host retinas for at least 5 months (rat) to over 2 years (monkey). In 4 of 7 transplanted rat retinas, RGC light responses were detected at the grafted area. A mild recovery of light perception was also suggested by the VGS performance 1.5 years after transplantation in that monkey. Interpretation: Our results support the competency of hiPSC-derived retinas to be clinically applied for transplantation therapy in retinal degeneration, although the light responses observed in the present models were not conclusively distinguishable from residual functions of degenerating host retinas. The functional analysis may be further elaborated using other models with more advanced retinal degeneration.
关键词： Human iPSC,Retinal degeneration,Photoreceptor transplantation,Visually-guided saccades,Multi-electrode array
更新于2025-09-04 15:30:14
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A Novel Method for Quantitative Serial Autofluorescence Analysis in Retinitis Pigmentosa Using Image Characteristics
摘要： Identifying potential biomarkers for disease progression in retinitis pigmentosa (RP) is highly relevant now that gene therapy and other treatments are in clinical trial. Here we report a novel technique for analysis of short-wavelength autofluorescence (AF) imaging to quantify defined regions of AF in RP patients. Methods: Fifty-five–degree AF images were acquired from 12 participants with RP over a 12-month period. Of these, five were identified as having a hyperfluorescent annulus. A standard Cartesian coordinate system was superimposed on images with the fovea as the origin and eight bisecting lines traversing the center at 45 degrees to each other. Spatial extraction software was programmed to highlight pixels corresponding to varying degrees of percentile fluorescence such that the parafoveal AF ring was mapped. Distance between the fovea and midpoint of the AF ring was measured. Percentage of low luminance areas was utilized as a measure of atrophy. Results: The hyperfluorescent ring was most accurately mapped using the 70th percentile of fluorescence. Both the AF ring and peripheral hypofluorescence showed robust repeatability at all time points noted (P ? 0.93). Conclusions: Both a hypofluorescent ring and retinal pigment epithelium atrophy were present on a significant proportion of RP patients and were consistently mapped over a 12-month period. There is potential extrapolation of this methodology to wide-field imaging as well as other retinal dystrophies. This anatomical change may provide a useful anatomical biomarker for assessing treatment end points in RP. Translational Relevance: Spatial extraction software can be a valuable tool in the assessment of ophthalmic imaging data.
关键词： autofluorescence,retinal degeneration,quantification,retinitis pigmentosa
更新于2025-09-04 15:30:14
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Developing an Outcome Measure With High Luminance for Optogenetics Treatment of Severe Retinal Degenerations and for Gene Therapy of Cone Diseases
摘要： PURPOSE. To present stimuli with varied sizes, colors, and patterns over a large range of luminance. METHODS. The ?lter bar used in scotopic MP1 was replaced with a custom slide-in tray that introduces light from an external projector driven by an additional computer. MP1 software was modi?ed to provide retinal tracking information to the computer driving the projector. Retinal tracking performance was evaluated by imaging the system input and the output simultaneously with a high-speed video system. Spatial resolution was measured with achromatic and chromatic grating/background combinations over scotopic and photopic ranges. RESULTS. The range of retinal illuminance achievable by the modi?cation was up to 6.8 log photopic Trolands (phot-Td); however, in the current work, only a lower range over (cid:2)4 to t3 log phot-Td was tested in human subjects. Optical magni?cation was optimized for low-vision testing with gratings from 4.5 to 0.2 cyc/deg. In normal subjects, spatial resolution driven by rods, short wavelength-sensitive (S-) cones, and long/middle wavelength-sensitive (L/M-) cones was obtained by the choice of adapting conditions and wavelengths of grating and background. Data from a patient with blue cone monochromacy was used to con?rm mediation. CONCLUSIONS. The modi?ed MP1 can be developed into an outcome measure for treatments in patients with severe retinal degeneration, very low vision, and abnormal eye movements such as those for whom treatment with optogenetics is planned, as well as for patients with cone disorders such as blue cone monochromacy for whom treatment with gene therapy is planned to improve L/M-cone function above a normal complement of rod and S-cone function.
关键词： retinal degeneration,outcome measures,low vision,optogenetics,channelrhodopsin
更新于2025-09-04 15:30:14
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<i>In vitro</i> and <i>in vivo</i> Proteomic Comparison of Human Neural Progenitor Cell-Induced Photoreceptor Survival
摘要： Retinal degenerative diseases are some of the leading causes of blindness with few treatments. Various cell-based therapies have aimed to slow the progression of vision loss by preserving light-sensing photoreceptor cells. A subretinal injection of human neural progenitor cells (hNPCs) into the Royal College of Surgeons (RCS) rat model of retinal degeneration has aided in photoreceptor survival, though the mechanisms are mainly unknown. Identifying the retinal proteomic changes that occur following hNPC treatment will lead to better understanding of neuroprotection. To mimic the retinal environment following hNPC injection, a co-culture system of retinas and hNPCs was developed. Less cell death occurred in RCS retinal tissue co-cultured with hNPCs than in retinas cultured alone, suggesting that hNPCs provide retinal protection in vitro. Comparison of ex vivo and in vivo retinas identified NRF2-mediated oxidative response signaling as an hNPC-induced pathway. This is the first study to compare proteomic changes following treatment with hNPCs in both an ex vivo and in vivo environment, further allowing the use of ex vivo modeling for mechanisms of retinal preservation. Elucidation of the protein changes in the retina following hNPC treatment may lead to the discovery of mechanisms of photoreceptor survival and its therapeutic for clinical applications.
关键词： retinal degeneration,stem cells,transplantation,Human neural progenitor cells,neuroprotection
更新于2025-09-04 15:30:14