scholarly journals Immunologic Rejection of Transplanted Retinal Pigmented Epithelium: Mechanisms and Strategies for Prevention

2021 ◽  
Vol 12 ◽  
Author(s):  
Carson C. Petrash ◽  
Alan G. Palestine ◽  
M. Valeria Canto-Soler
Keyword(s):  
Functional Assessment ◽  
Imaging Techniques ◽  
Allogeneic Transplantation ◽  
Subretinal Space ◽  
Retinal Pigmented Epithelium ◽  
Number Of Factors ◽  
Retinal Disorders ◽  
Pigmented Epithelium ◽  
Complicating Factors ◽  
Individual Strategies

Replacement of dysfunctional retinal pigmented epithelium (RPE) with grafts derived from stem cells has the potential to improve vision for patients with retinal disorders. In fact, the potential is such that a great number of groups are attempting to realize this therapy through individual strategies with a variety of stem cell products, hosts, immunomodulatory regimen, and techniques to assess the success of their design. Comparing the findings of different investigators is complicated by a number of factors. The immune response varies greatly between xenogeneic and allogeneic transplantation. A unique immunologic environment is created in the subretinal space, the target of RPE grafts. Both functional assessment and imaging techniques used to evaluate transplants are susceptible to erroneous conclusions. Lastly, the pharmacologic regimens used in RPE transplant trials are as numerous and variable as the trials themselves, making it difficult to determine useful results. This review will discuss the causes of these complicating factors, digest the strategies and results from clinical and preclinical studies, and suggest places for improvement in the design of future transplants and investigations.

scholarly journals EFFECTS OF CYCLIC AMP AND SEPHADEX FRACTIONS OF CHICK EMBRYO EXTRACT ON CLONED RETINAL PIGMENTED EPITHELIUM IN TISSUE CULTURE

1974 ◽  
Vol 61 (2) ◽  
pp. 369-382 ◽  
Author(s):  
D. A. Newsome ◽  
R. T. Fletcher ◽  
W. G. Robison ◽  
K. R. Kenyon ◽  
G. J. Chader
Keyword(s):  
Molecular Weight ◽  
Chick Embryo ◽  
Adenosine Monophosphate ◽  
Cell Number ◽  
Retinal Pigmented Epithelium ◽  
Culture Dish ◽  
Adhesive Properties ◽  
Embryo Extract ◽  
Chick Embryo Extract ◽  
Pigmented Epithelium

The effects of dibutyryl cyclic 3',5'-adenosine monophosphate (BcAMP) and Sephadex G-25 fractions of chick embryo extract on the growth rate, morphology, and pigmentation of normal chick retinal pigmented epithelium (PE) were investigated. Seven cloned PE cell lines were each grown in modified Ham's F-12 medium alone (F-12), or in F-12 supplemented with either high molecular weight (H) or low molecular weight (L) fractions of chick embryo extract. Cells grown in F-12 alone or in L medium formed compact epithelial sheets, whereas cells grown in H had a fibrocytic appearance and formed poorly organized monolayers. In H plus BcAMP, cell morphology was more epithelioid than in H alone, and generally the monolayers appeared more differentiated. Under each of these three culture conditions, 2 x 10-4 M BCAMP retarded the increase in cell number and decreased the final number of cells per culture dish, but had little effect on plating efficiency. BcAMP also increased the rate of cell adhesion to a plastic substratum. Pigmentation was marked in cultures grown in F-12 or in L alone, but the addition of BcAMP dramatically reduced visible pigmentation. This effect was reversed when BcAMP was removed from the culture medium. Thus BcAMP modifies cell and colonial morphology, rate of cell accumulation, adhesive properties, and pigmentation of normal PE cells.

scholarly journals Five Recombinant Simian Immunodeficiency Virus Pseudotypes Lead to Exclusive Transduction of Retinal Pigmented Epithelium in Rat

2002 ◽  
Vol 6 (4) ◽  
pp. 446-454 ◽  
Author(s):  
Ghislaine Duisit ◽  
Hervé Conrath ◽  
Sylvie Saleun ◽  
Sebastien Folliot ◽  
Nathalie Provost ◽  
...  
Keyword(s):  
Simian Immunodeficiency Virus ◽  
Retinal Pigmented Epithelium ◽  
Immunodeficiency Virus ◽  
Pigmented Epithelium

AGEs Promote Oxidative Stress and Induce Apoptosis in Retinal Pigmented Epithelium Cells RAGE-dependently

2015 ◽  
Vol 56 (2) ◽  
pp. 449-460 ◽  
Author(s):  
Xin-Ling Wang ◽  
Tao Yu ◽  
Qi-Chang Yan ◽  
Wei Wang ◽  
Nan Meng ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Retinal Pigmented Epithelium ◽  
Pigmented Epithelium ◽  
Epithelium Cells

scholarly journals Reprogramming of the chick retinal pigmented epithelium after retinal injury

BMC Biology ◽  
2014 ◽  
Vol 12 (1) ◽  
pp. 28 ◽  
Author(s):  
Agustin Luz-Madrigal ◽  
Erika Grajales-Esquivel ◽  
Alexander McCorkle ◽  
Ashley M DiLorenzo ◽  
Karla Barbosa-Sabanero ◽  
...  
Keyword(s):  
Retinal Pigmented Epithelium ◽  
Retinal Injury ◽  
Pigmented Epithelium

Melanogenesis in amphibians

Development ◽  
1970 ◽  
Vol 24 (2) ◽  
pp. 447-454
Author(s):  
John J. Eppig
Keyword(s):  
Electron Microscopy ◽  
Epithelial Cells ◽  
Notophthalmus Viridescens ◽  
Retinal Pigmented Epithelium ◽  
Pigmented Epithelium ◽  
In Cells

Electron microscopy of 11-day-old Notophthalmus viridescens retinal pigmented epithelium reveals particulate premelanosomes which are identical to the melanosomes found in the oocyte. These organelles, when found in the pigmented epithelium, are called premelanosomes because they undergo further maturation to form relatively homogeneous, spherical melanosomes. At this stage, oocyte melanosomes found in cells other than melanocytes have not undergone this subsequent maturation. Elongated melanosomes which develop from fibrillar premelanosomes are also found in the pigmented epithelial cells. Treatment with phenylthiourea blocks the maturation of both the fibrillar and particulate premelanosomes.

Bilateral fungal infection inducing a serpiginous-like picture

2020 ◽  
pp. 112067212090872
Author(s):  
Alvaro Fernández-Vega González ◽  
Carlos Fernández-Vega González ◽  
Beatriz Fernández-Vega Sanz ◽  
María Teresa Peláez ◽  
Jesús Merayo-Lloves
Keyword(s):  
Visual Acuity ◽  
Fungal Infection ◽  
Inflammatory Diseases ◽  
Histopathological Examination ◽  
Clinical Findings ◽  
Blood Analysis ◽  
Retinal Pigmented Epithelium ◽  
Pigmented Epithelium ◽  
Laboratory Investigations ◽  
The Right

Purpose: To report the clinical findings of a patient who presented with an atypical bilateral fungal retinitis that was established by retinochoroidal biopsy. Methods: Case report. Results: A 56-year-old systemically healthy man presented with progressive visual loss in his left eye for 3 weeks. Visual acuity was 20/40 in the left eye, and 20/20 in the right eye and fundus examination showed macular retinal pigmented epithelium changes in his left eye. Over the following four months, his lesions progressed to serpiginous-like widespread retinal pigmented epithelium atrophy and his visual acuity decreased to 20/100, but no signs of ocular inflammation were found. Treatment with oral corticoids, valganciclovir and trimethoprim/sulfamethoxazole showed no efficacy. Blood analysis and cultures, laboratory investigations, and imaging tests were carried out looking for infectious and inflammatory diseases, but all tests were negative. Two months later, the patient presented with the same kind of lesions in the other eye (right eye), so he was subjected to retinochoroidal biopsy. Histopathological examination of specimen revealed the presence of intraretinal and choroidal fungal hyphae. Oral voriconazole was initiated achieving clinical remission, but no visual improvement was obtained. The source of the infection remains unknown since all tests results were negative. However, his profession as brewmaster might be related to the origin of the infection. Conclusion: Diagnosis of intraocular fungal infection can be challenging. Retinochoroidal biopsy may be useful to establish the diagnosis in those atypical cases with nonrevealing workup and inflammation localized to the retina.

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