https://escholarship.org/content/qt37v8z78v/qt37v8z78v.pdf?t=o94eyx

Can subretinal microphotodiodes successfully replace degenerated photoreceptors

Progressive photoreceptor degeneration resulting from genetic and other factors is a leading and largely untreatable cause of blindness worldwide. The object of this study was to find a cell type that is effective in slowing the progress of such degeneration in an animal model of human retinal disease, is safe, and could be generated in sufficient numbers for clinical application. We have compared efficacy of four human-derived cell types in preserving photoreceptor integrity and visual functions after injection into the subretinal space of the Royal College of Surgeons rat early in the progress of degeneration. Umbilical tissue-derived cells, placenta-derived cells, and mesenchymal stem cells were studied; dermal fibroblasts served as cell controls. At various ages up to 100 days, electroretinogram responses, spatial acuity, and luminance threshold were measured. Both umbilical-derived and mesenchymal cells significantly reduced the degree of functional deterioration in each test. The effect of placental cells was not much better than controls. Umbilical tissue-derived cells gave large areas of photoreceptor rescue; mesenchymal stem cells gave only localized rescue. Fibroblasts gave sham levels of rescue. Donor cells were confined to the subretinal space. There was no evidence of cell differentiation into neurons, of tumor formation or other untoward pathology. Since the umbilical tissue-derived cells demonstrated the best photoreceptor rescue and, unlike mesenchymal stem cells, were capable of sustained population doublings without karyotypic changes, it is proposed that they may provide utility as a cell source for the treatment of retinal degenerative diseases such as retinitis pigmentosa.

https://stemcellsjournals.onlinelibrary.wiley.com/doi/pdf/10.1634/stemcells.2006-0308

Cells Isolated from Umbilical Cord Tissue Rescue Photoreceptors and Visual Functions in a Rodent Model of Retinal Disease

RPE transplantation and its role in retinal disease.

Development of human embryonic stem cell therapies for age-related macular degeneration

It is believed that a major reason for the poor functional recovery after peripheral nerve lesion is collateral branching and regrowth of axons to incorrect muscles. Using a facial nerve injury protocol in rats, we previously identified a novel and clinically feasible approach to combat axonal misguidance--the application of neutralizing antibodies against neurotrophic factors to the injured nerve. Here, we investigated whether reduced collateral branching at the lesion site leads to better functional recovery. Treatment of rats with antibodies against nerve growth factor, brain-derived neurotrophic factor, fibroblast growth factor, insulin-like neurotrophic factor I, ciliary neurotrophic factor or glial cell line-derived neurotrophic factor increased the precision of reinnervation, as evaluated by multiple retrograde labelling of motoneurons, more than two-fold as compared with control animals. However, biometric analysis of vibrissae movements did not show positive effects on functional recovery, suggesting that polyneuronal reinnervation--rather than collateral branching --may be the critical limiting factor. In support of this hypothesis, we found that motor end-plates with morphological signs of multiple innervation were much more frequent in reinnervated muscles of rats that did not recover after injury (51% of all end-plates) than in animals with good functional performance (10%). Because polyneuronal innervation of muscle fibres is activity-dependent and can be manipulated, the present findings raise hopes that clinically feasible and effective therapies could be soon designed and tested.

Factors limiting motor recovery after facial nerve transection in the rat: combined structural and functional analyses

https://www.cell.com/trends/neurosciences/pdf/0166-2236(91)90160-V.pdf

Transplantation to the diseased and damaged retina.

Publisher Summary This chapter describes the effects of retinal pigment epithelial (RPE) cell transplants in the retinas of Royal College of Surgeons (RCS) dystrophic rats. The chapter describes the mechanism by which RPE cell transplants affect the survival of photoreceptor cells in dystrophic retinas and in vitro. Retinal cell transplantation and techniques are also presented in the chapter. Prior to and during the early stages of the study of RPE cell transplantation, retinas as whole or partial segments or as cell suspensions had been grafted into mammalian eyes. Various methods were employed to transplant donor retinal tissue—intact or as a cell suspension—into a host eye. Often the donor tissue was of embryonic or neonatal origin, while the host animals were adults. The anterior chamber in rats was used as a suitable environment for retinal tissue transplantation. Small pieces of retina from newborn rats were transplanted into a retinal lesion bordered by the vitreous using a transscleral approach. Photoreceptor cells as an intact layer survived for several weeks when transplanted into light-damaged and dystrophic retinas. Exposing adult rats to excess light destroyed most photoreceptor cells within a few weeks, while the inner retina remained relatively unchanged.

Photoreceptor rescue in the dystrophic retina by transplantation of retinal pigment epithelium.

PURPOSE Healthy retinal pigment epithelial (RPE) cell transplants in retinas of postnatal day 27 Royal College of Surgeons (RCS) rat are capable of preventing photoreceptor cell degeneration, inhibiting the degeneration of the retinal vascular bed and the subsequent neovascularization of the RPE that occurs in retinas injected with saline. In the present study, the authors have tested the hypothesis that RPE transplants might also prevent vascularization of the RPE layer in RCS retinas when photoreceptor cells either had just degenerated or, at 3 months, disappeared. METHOD Retinas of 3- and 6 month-old RCS rats were injected with either healthy neonatal RPE cells or vehicle and were examined at 6 and 8 months, respectively. These retinas were studied using horseradish peroxidase visualization of the vasculature in retinal wholemount preparations and by light microscopy. RESULTS The number of neovascular profiles in wholemount preparations of RCS retinas that had received healthy RPE transplants at 3 months and were analyzed at 6 months were significantly decreased when compared to sham-injected retinas of age-matched RCS rats, 2.09 +/- 0.94 and 15.28 +/- 1.34 profiles per mm2, respectively (P < 0.001). In addition, when comparing retinas transplanted or sham injected at 6 months and examined at 8 months, significantly fewer neovascular profiles were found in the transplant group, 9.32 +/- 1.02 and 15.42 +/- 0.84 profiles per mm2, respectively (P < 0.002). CONCLUSION These data provide still further evidence for the role of healthy RPE in maintaining the homeostasis of the normal retinal vasculature in the retina of the RCS rat. The relationships between the RPE and the retinal vasculature are important when considering that alterations in the vascularization of the retina play a major role in some of the most sight-debilitating diseases, such as the wet form of age-related macular degeneration and proliferative diabetic retinopathy.

A primary role for RPE transplants in the inhibition and regression of neovascularization in the RCS rat.

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Anthony D. Seaton

Author Tools

Chat about Author

Papers

Transplantation to the diseased and damaged retina.

Photoreceptor rescue in the dystrophic retina by transplantation of retinal pigment epithelium.

A primary role for RPE transplants in the inhibition and regression of neovascularization in the RCS rat.