scholarly journals Ccr2 suppression by minocycline in Cx3cr1/Ccr2-visualized inherited retinal degeneration

2020 ◽  
Author(s):  
Ryo Terauchi ◽  
Hideo Kohno ◽  
Sumiko Watanabe ◽  
Saburo Saito ◽  
Akira Watanabe ◽  
...  
Keyword(s):  
Retinal Degeneration ◽  
Expression Pattern ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Rescue Effect ◽  
Ccr2 Expression ◽  
Retinal Inflammation ◽  
Inherited Retinal Degeneration ◽  
Old Mice ◽  
Cx3cr1 Expression

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.

scholarly journals Study of the functional integrity of the retinal pigment epithelium with a new technique in two models of inherited retinal degeneration

2019 ◽  
Vol 97 (S263) ◽  
Author(s):  
Johnny Di Pierdomenico ◽  
Francisco Javier Valiente Soriano ◽  
Manuel Salinas Navarro ◽  
Diego García‐Ayuso ◽  
María Paz Villegas‐Pérez ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Retinal Degeneration ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
New Technique ◽  
Functional Integrity ◽  
A New Technique ◽  
Inherited Retinal Degeneration

scholarly journals Potential Treatment of Retinal Diseases with Iron Chelators

2018 ◽  
Vol 11 (4) ◽  
pp. 112 ◽  
Author(s):  
Wanting Shu ◽  
Joshua Dunaief
Keyword(s):  
Retinal Degeneration ◽  
Therapeutic Potential ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
The Body ◽  
Age Related Macular Degeneration ◽  
Hereditary Diseases ◽  
Iron Chelators ◽  
Excess Iron ◽  
Age Related

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.

scholarly journals Impaired ABCA1/ABCG1-mediated lipid efflux in the mouse retinal pigment epithelium (RPE) leads to retinal degeneration

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Federica Storti ◽  
Katrin Klee ◽  
Vyara Todorova ◽  
Regula Steiner ◽  
Alaa Othman ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Progressive Disease ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Central Vision ◽  
Atp Binding Cassette Transporter ◽  
Lipid Efflux ◽  
Age Related ◽  
Retinal Inflammation

Age-related macular degeneration (AMD) is a progressive disease of the retinal pigment epithelium (RPE) and the retina leading to loss of central vision. Polymorphisms in genes involved in lipid metabolism, including the ATP-binding cassette transporter A1 (ABCA1), have been associated with AMD risk. However, the significance of retinal lipid handling for AMD pathogenesis remains elusive. Here, we study the contribution of lipid efflux in the RPE by generating a mouse model lacking ABCA1 and its partner ABCG1 specifically in this layer. Mutant mice show lipid accumulation in the RPE, reduced RPE and retinal function, retinal inflammation and RPE/photoreceptor degeneration. Data from human cell lines indicate that the ABCA1 AMD risk-conferring allele decreases ABCA1 expression, identifying the potential molecular cause that underlies the genetic risk for AMD. Our results highlight the essential homeostatic role for lipid efflux in the RPE and suggest a pathogenic contribution of reduced ABCA1 function to AMD.

scholarly journals Quantitative metabolomics of photoreceptor degeneration and the effects of stem cell-derived retinal pigment epithelium transplantation

2016 ◽  
Vol 374 (2079) ◽  
pp. 20150376 ◽  
Author(s):  
Junhua Wang ◽  
Peter D. Westenskow ◽  
Mingliang Fang ◽  
Martin Friedlander ◽  
Gary Siuzdak
Keyword(s):  
Stem Cell ◽  
Retinal Pigment Epithelium ◽  
Retinal Degeneration ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Photoreceptor Degeneration ◽  
Quantitative Metabolomics ◽  
Fatty Acid Amides ◽  
Age Related

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’.

scholarly journals Retinal degeneration triggered by inactivation of PTEN in the retinal pigment epithelium

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

scholarly journals Pharmacological inhibition of MERTK induces in vivo retinal degeneration: a multimodal imaging ocular safety assessment

2022 ◽  
Author(s):  
Gregory Hamm ◽  
Gareth Maglennon ◽  
Beth Williamson ◽  
Ruth Macdonald ◽  
Ann Doherty ◽  
...  
Keyword(s):  
Retinal Degeneration ◽  
Cell Model ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Cell ◽  
Knock Out ◽  
Pharmacological Inhibition ◽  
Ocular Safety ◽  
Knock Out Mouse

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.

scholarly journals THE CIRCADIAN CLOCK IN THE RETINAL PIGMENT EPITHELIUM CONTROLS THE DIURNAL RHYTHM OF PHAGOCYTIC ACTIVITY

2020 ◽  
Author(s):  
Christopher DeVera ◽  
Jendayi Dixon ◽  
Micah A. Chrenek ◽  
Kenkichi Baba ◽  
P. Michael Iuvone ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Circadian Clock ◽  
Phagocytic Activity ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Optomotor Response ◽  
Rpe Cells ◽  
Photoreceptor Outer Segments ◽  
Outer Segments ◽  
Old Mice

AbstractThe diurnal peak of phagocytosis by the retinal pigment epithelium (RPE) of photoreceptor outer segments (POS) is under circadian control, and it is believed that this process involves interactions from both the retina and RPE. Previous studies have demonstrated that a functional circadian clock exists within multiple retinal cell types and RPE cells. Thereby, the aim of the current study was to determine whether the circadian clock in the retina and or RPE controls the diurnal phagocytic peak of photoreceptor outer segments and whether selective disruption of the circadian clock in the RPE would affect RPE cells function and the viability during aging. To that aim, we first generated and validated an RPE tissue-specific KO of the essential clock gene, Bmal1, and then we determined the daily rhythm in phagocytic activity by the RPE in mice lacking a functional circadian clock in the retina or RPE. Then using electroretinography, spectral domain-optical coherence tomography, and optomotor response measurements of visual function we determined the effect of Bmal1 removal in young (6-month old) and old (18-month old) mice. RPE morphology and lipofuscin accumulation was also determined in young and old mice. Our data show that the circadian clock in the RPE controls the daily diurnal phagocytic peak of POS. Surprisingly, the lack of a functional RPE circadian clock or the diurnal phagocytic peak does not result in any detectable age-related degenerative phenotype in the retina or RPE. Thus, our results demonstrate that the loss of the circadian clock in the RPE or the lack of the daily peak in phagocytosis of POS does not result in deterioration of photoreceptors or the RPE during aging.

Sign in / Sign up

Export Citation Format

Share Document