scholarly journals Selective Ablation of Megalin in the Retinal Pigment Epithelium Results in Megaophthalmos, Macromelanosome Formation and Severe Retina Degeneration

2019 ◽  
Vol 60 (1) ◽  
pp. 322 ◽  
Author(s):  
Tina Storm ◽  
Thomas Burgoyne ◽  
Joshua L. Dunaief ◽  
Erik I. Christensen ◽  
Clare Futter ◽  
...  
Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 771 ◽  
Author(s):  
Marci L. DeRamus ◽  
Stephanie J. Davis ◽  
Sriganesh Ramachandra Rao ◽  
Cyril Nyankerh ◽  
Delores Stacks ◽  
...  

Patients with certain defects in the dehydrodolichyl diphosphate synthase (DHDDS) gene (RP59; OMIM #613861) exhibit classic symptoms of retinitis pigmentosa, as well as macular changes, suggestive of retinal pigment epithelium (RPE) involvement. The DHDDS enzyme is ubiquitously required for several pathways of protein glycosylation. We wish to understand the basis for selective ocular pathology associated with certain DHDDS mutations and the contribution of specific ocular cell types to the pathology of mutant Dhdds-mediated retinal degeneration. To circumvent embryonic lethality associated with Dhdds knockout, we generated a Cre-dependent knockout allele of murine Dhdds (Dhddsflx/flx). We used targeted Cre expression to study the importance of the enzyme in the RPE. Structural alterations of the RPE and retina including reduction in outer retinal thickness, cell layer disruption, and increased RPE hyper-reflectivity were apparent at one postnatal month. At three months, RPE and photoreceptor disruption was observed non-uniformly across the retina as well as RPE transmigration into the photoreceptor layer, external limiting membrane descent towards the RPE, and patchy loss of photoreceptors. Functional loss measured by electroretinography was consistent with structural loss showing scotopic a- and b-wave reductions of 83% and 77%, respectively, at three months. These results indicate that RPE dysfunction contributes to DHDDS mutation-mediated pathology and suggests a more complicated disease mechanism than simply disruption of glycosylation.


Author(s):  
G.E. Korte ◽  
M. Marko ◽  
G. Hageman

Sodium iodate iv. damages the retinal pigment epithelium (RPE) in rabbits. Where RPE does not regenerate (e.g., 1,2) Muller glial cells (MC) forma subretinal scar that replaces RPE. The MC response was studied by HVEM in 3D computer reconstructions of serial thick sections, made using the STEREC0N program (3), and the HVEM at the NYS Dept. of Health in Albany, NY. Tissue was processed for HVEM or immunofluorescence localization of a monoclonal antibody recognizing MG microvilli (4).


Marine Drugs ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 1
Author(s):  
Peeraporn Varinthra ◽  
Shun-Ping Huang ◽  
Supin Chompoopong ◽  
Zhi-Hong Wen ◽  
Ingrid Y. Liu

Age-related macular degeneration (AMD) is a progressive eye disease that causes irreversible impairment of central vision, and effective treatment is not yet available. Extracellular accumulation of amyloid-beta (Aβ) in drusen that lie under the retinal pigment epithelium (RPE) has been reported as one of the early signs of AMD and was found in more than 60% of Alzheimer’s disease (AD) patients. Extracellular deposition of Aβ can induce the expression of inflammatory cytokines such as IL-1β, TNF-α, COX-2, and iNOS in RPE cells. Thus, finding a compound that can effectively reduce the inflammatory response may help the treatment of AMD. In this research, we investigated the anti-inflammatory effect of the coral-derived compound 4-(phenylsulfanyl) butan-2-one (4-PSB-2) on Aβ1-42 oligomer (oAβ1-42) added to the human adult retinal pigment epithelial cell line (ARPE-19). Our results demonstrated that 4-PSB-2 can decrease the elevated expressions of TNF-α, COX-2, and iNOS via NF-κB signaling in ARPE-19 cells treated with oAβ1-42 without causing any cytotoxicity or notable side effects. This study suggests that 4-PSB-2 is a promising drug candidate for attenuation of AMD.


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