Features of local expression of mRNA, IL-1 ß, IL-18, CCL2/MCP-1 in modeling pigment epithelium atrophy and retinal degeneration in the experiment on rabbits

2021 ◽  
Vol 19 (2) ◽  
pp. 54-62
Author(s):  
Vladimir Vladimirovich Neroev ◽  
Natalya Vladimirovna Balatskaya ◽  
Elena Victorovna Svetlova ◽  
Natalia Vladimirovna Neroeva ◽  
Marina Vladimirovna Ryabina ◽  
...  
2018 ◽  
Vol 11 (4) ◽  
pp. 112 ◽  
Author(s):  
Wanting Shu ◽  
Joshua Dunaief

Iron is essential for life, while excess iron can be toxic. Iron generates hydroxyl radical, which is the most reactive free radical, causing oxidative stress. Since iron is absorbed through the diet but not excreted from the body, it accumulates with age in tissues, including the retina, consequently leading to age-related toxicity. This accumulation is further promoted by inflammation. Hereditary diseases such as aceruloplasminemia, Friedreich’s ataxia, pantothenate kinase-associated neurodegeneration, and posterior column ataxia with retinitis pigmentosa involve retinal degeneration associated with iron dysregulation. In addition to hereditary causes, dietary or parenteral iron supplementation has been recently reported to elevate iron levels in the retinal pigment epithelium (RPE) and promote retinal degeneration. Ocular siderosis from intraocular foreign bodies or subretinal hemorrhage can also lead to retinopathy. Evidence from mice and humans suggests that iron toxicity may contribute to age-related macular degeneration pathogenesis. Iron chelators can protect photoreceptors and RPE in various mouse models. The therapeutic potential for iron chelators is under investigation.


1984 ◽  
Vol 21 (1) ◽  
pp. 18-27 ◽  
Author(s):  
W. J. Hadlow

Retinal degeneration was prevalent in a large group of sapphire and pastel mink (Mustela vison) kept for studies on slow viral diseases. Nearly 78% of those two to eight years old were affected. The retinopathy was equally common in both sexes but more frequent in sapphires (85%) than in pastels (63%), and it was severe more often in sapphires than in pastels. By light microscopy, the primary change appeared to be progressive degeneration of fully developed photoreceptors, beginning in their outer segments. In many mink, including some younger ones, the rods and cones and outer nuclear layer had disappeared from all but the far periphery of the fundus. The inner retinal layers were spared until late in the disease, and the pigment epithelium remained essentially unchanged. The cause of the retinopathy was not established. It may represent an abiotrophy in which the structural integrity of the photoreceptors began to wane in many mink after they reached two years of age. Apart from reducing visual acuity, the retinopathy has implications for the photoperiodic control of fur growth and reproduction in this highly light-sensitive carnivore.


Author(s):  
Junhua Wang ◽  
Peter D. Westenskow ◽  
Mingliang Fang ◽  
Martin Friedlander ◽  
Gary Siuzdak

Photoreceptor degeneration is characteristic of vision-threatening diseases including age-related macular degeneration. Photoreceptors are metabolically demanding cells in the retina, but specific details about their metabolic behaviours are unresolved. The quantitative metabolomics of retinal degeneration could provide valuable insights and inform future therapies. Here, we determined the metabolomic ‘fingerprint’ of healthy and dystrophic retinas in rat models using optimized metabolite extraction techniques. A number of classes of metabolites were consistently dysregulated during degeneration: vitamin A analogues, fatty acid amides, long-chain polyunsaturated fatty acids, acyl carnitines and several phospholipid species. For the first time, a distinct temporal trend of several important metabolites including DHA (4Z,7Z,10Z,13Z,16Z,19Z-docosahexaenoic acid), all- trans -retinal and its toxic end-product N -retinyl- N -retinylidene-ethanolamine were observed between healthy and dystrophic retinas. In this study, metabolomics was further used to determine the temporal effects of the therapeutic intervention of grafting stem cell-derived retinal pigment epithelium (RPE) in dystrophic retinas, which significantly prevented photoreceptor atrophy in our previous studies. The result revealed that lipid levels such as phosphatidylethanolamine in eyes were restored in those animals receiving the RPE grafts. In conclusion, this study provides insight into the metabolomics of retinal degeneration, and further understanding of the efficacy of RPE transplantation. This article is part of the themed issue ‘Quantitative mass spectrometry’.


2008 ◽  
Vol 22 (22) ◽  
pp. 3147-3157 ◽  
Author(s):  
J. W. Kim ◽  
K. H. Kang ◽  
P. Burrola ◽  
T. W. Mak ◽  
G. Lemke

Author(s):  
Gregory Hamm ◽  
Gareth Maglennon ◽  
Beth Williamson ◽  
Ruth Macdonald ◽  
Ann Doherty ◽  
...  

AbstractThe receptor tyrosine kinase, MERTK, plays an essential role in homeostasis of the retina via efferocytosis of shed outer nuclear segments of photoreceptors. The Royal College of Surgeons rat model of retinal degeneration has been linked to loss-of-function of MERTK, and together with the MERTK knock-out mouse, phenocopy retinitis pigmentosa in humans with MERTK mutations. Given recent efforts and interest in MERTK as a potential immuno-oncology target, development of a strategy to assess ocular safety at an early pre-clinical stage is critical. We have applied a state-of-the-art, multi-modal imaging platform to assess the in vivo effects of pharmacological inhibition of MERTK in mice. This involved the application of mass spectrometry imaging (MSI) to characterize the ocular spatial distribution of our highly selective MERTK inhibitor; AZ14145845, together with histopathology and transmission electron microscopy to characterize pathological and ultra-structural change in response to MERTK inhibition. In addition, we assessed the utility of a human retinal in vitro cell model to identify perturbation of phagocytosis post MERTK inhibition. We identified high localized total compound concentrations in the retinal pigment epithelium (RPE) and retinal lesions following 28 days of treatment with AZ14145845. These lesions were present in 4 of 8 treated animals, and were characterized by a thinning of the outer nuclear layer, loss of photoreceptors (PR) and accumulation of photoreceptor outer segments at the interface of the RPE and PRs. Furthermore, the lesions were very similar to that shown in the RCS rat and MERTK knock-out mouse, suggesting a MERTK-induced mechanism of PR cell death. This was further supported by the observation of reduced phagocytosis in the human retinal cell model following treatment with AZ14145845. Our study provides a viable, translational strategy to investigate the pre-clinical toxicity of MERTK inhibitors but is equally transferrable to novel chemotypes.


2020 ◽  
Author(s):  
Ryo Terauchi ◽  
Hideo Kohno ◽  
Sumiko Watanabe ◽  
Saburo Saito ◽  
Akira Watanabe ◽  
...  

AbstractRetinal inflammation accelerates photoreceptor cell death (PCD) caused by retinal degeneration. Minocycline, a semisynthetic broad-spectrum tetracycline antibiotic, has previously been reported to show PCD rescue effect in retinal degeneration. The purpose of this study was to assess the effect of minocycline on Cx3cr1 and Ccr2 expression in retinal degeneration. Mertk-/-Cx3cr1GFP/+Ccr2RFP/+ mice, which enabled observation of Cx3cr1- and Ccr2-expression pattern in inherited retinal degeneration, were used to test the effect of minocycline. Minocycline was systemically administered to Mertk-/-Cx3cr1GFP/+Ccr2RFP/+ mice. For observing the effect of minocycline on Cx3cr1 and Ccr2 expression, administration was started on 4-week-old mice and continued for 2 weeks. To assess the PCD rescue effect, minocycline was administered to 6-week-old mice for 2 weeks. The expression pattern of Cx3cr1-GFP and Ccr2-RFP were observed on retinal and retinal pigment epithelium (RPE) flat-mounts. The severity of retinal degeneration was assessed on retinal sections. Minocycline administration suppressed Ccr2 expression in Mertk-/-Cx3cr1GFP/+Ccr2RFP/+ mice as observed in retinal and RPE flat-mounts. On the contrary, Cx3cr1 expression was not affected by minocycline administration. Retinal degeneration is ameliorated in minocycline administered Mertk-/-Cx3cr1GFP/+Ccr2RFP/+ mice. In conclusions, Minocycline suppression of Ccr2 expression correlates to amelioration of retinal degeneration.


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