Müller Glia Cell Activation in a Laser-induced Retinal Degeneration and Regeneration Model in Zebrafish

A high-fat diet (HFD) can induce hyperglycemia and metabolic syndromes that, in turn, can trigger visual impairment. To evaluate the acute effects of HFD feeding on retinal degeneration, we assessed retinal function and morphology, inflammatory state, oxidative stress, and gut microbiome in dystrophic retinal degeneration 10 (rd10) mice, a model of retinitis pigmentosa, fed an HFD for 2 to 3 wk. Short-term HFD feeding impaired retinal responsiveness and visual acuity and enhanced photoreceptor degeneration, microglial cell activation, and Müller cell gliosis. HFD consumption also triggered the expression of inflammatory and oxidative markers in rd10 retinas. Finally, an HFD caused gut microbiome dysbiosis, increasing the abundance of potentially proinflammatory bacteria. Thus, HFD feeding drives the pathological processes of retinal degeneration by promoting oxidative stress and activating inflammatory-related pathways. Our findings suggest that consumption of an HFD could accelerate the progression of the disease in patients with retinal degenerative disorders.

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Microglia–Müller Glia Cell Interactions Control Neurotrophic Factor Production during Light-Induced Retinal Degeneration

Journal of Neuroscience ◽

10.1523/jneurosci.22-21-09228.2002 ◽

2002 ◽

Vol 22 (21) ◽

pp. 9228-9236 ◽

Cited By ~ 228

Author(s):

Takayuki Harada ◽

Chikako Harada ◽

Shinichi Kohsaka ◽

Etsuko Wada ◽

Kazuhiko Yoshida ◽

...

Keyword(s):

Retinal Degeneration ◽

Neurotrophic Factor ◽

Cell Interactions ◽

Muller Glia ◽

Müller Glia ◽

Glia Cell ◽

Factor Production

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Chronic acrylamide exposure induced glia cell activation, NLRP3 infl-ammasome upregulation and cognitive impairment

Toxicology and Applied Pharmacology ◽

10.1016/j.taap.2020.114949 ◽

2020 ◽

Vol 393 ◽

pp. 114949 ◽

Cited By ~ 1

Author(s):

Ying Liu ◽

Xing Zhang ◽

Dandan Yan ◽

Yiqi Wang ◽

Na Wang ◽

...

Keyword(s):

Cognitive Impairment ◽

Cell Activation ◽

Glia Cell

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Expression of the Endoplasmic Reticulum Stress Marker GRP78 in the Normal Retina and Retinal Degeneration Induced by Blue LED Stimuli in Mice

Cells ◽

10.3390/cells10050995 ◽

2021 ◽

Vol 10 (5) ◽

pp. 995

Author(s):

Yong Soo Park ◽

Hong-Lim Kim ◽

Seung Hee Lee ◽

Yan Zhang ◽

In-Beom Kim

Keyword(s):

Endoplasmic Reticulum ◽

Retinal Degeneration ◽

Glial Cells ◽

Cell Activation ◽

Outer Nuclear Layer ◽

Photoreceptor Cells ◽

Dependent Manner ◽

Normal Retina ◽

Perinuclear Space ◽

The Unfolded Protein Response

Retinal degeneration is a leading cause of blindness. The unfolded protein response (UPR) is an endoplasmic reticulum (ER) stress response that affects cell survival and death and GRP78 forms a representative protective response. We aimed to determine the exact localization of GRP78 in an animal model of light-induced retinal degeneration. Dark-adapted mice were exposed to blue light-emitting diodes and retinas were obtained at 24 h and 72 h after exposure. In the normal retina, we found that GRP78 was rarely detected in the photoreceptor cells while it was expressed in the perinuclear space of the cell bodies in the inner nuclear and ganglion cell layers. After injury, the expression of GRP78 in the outer nuclear and inner plexiform layers increased in a time-dependent manner. However, an increased GRP78 expression was not observed in damaged photoreceptor cells in the outer nuclear layer. GRP78 was located in the perinuclear space and ER lumen of glial cells and the ER developed in glial cells during retinal degeneration. These findings suggest that GRP78 and the ER response are important for glial cell activation in the retina during photoreceptor degeneration.

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Complement Factor H Loss in RPE Cells Causes Retinal Degeneration in a Human RPE-Porcine Retinal Explant Co-Culture Model

Biomolecules ◽

10.3390/biom11111621 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1621

Author(s):

Angela Armento ◽

Aparna Murali ◽

Julia Marzi ◽

Ana C Almansa-Garcia ◽

Blanca Arango-Gonzalez ◽

...

Keyword(s):

Retinal Degeneration ◽

Cell Activation ◽

Factor H ◽

Age Related Macular Degeneration ◽

Complement Factor H ◽

Complement Factor ◽

Rpe Cells ◽

Age Related ◽

Culture Model ◽

Retinal Explants

Age-related Macular degeneration (AMD) is a degenerative disease of the macula affecting the elderly population. Treatment options are limited, partly due to the lack of understanding of AMD pathology and the lack of suitable research models that replicate the complexity of the human macula and the intricate interplay of the genetic, aging and lifestyle risk factors contributing to AMD. One of the main genetic risks associated with AMD is located on the Complement Factor H (CFH) gene, leading to an amino acid substitution in the Factor H (FH) protein (Y402H). However, the mechanism of how this FH variant promotes the onset of AMD remains unclear. Previously, we have shown that FH deprivation in RPE cells, via CFH silencing, leads to increased inflammation, metabolic impairment and vulnerability toward oxidative stress. In this study, we established a novel co-culture model comprising CFH silenced RPE cells and porcine retinal explants derived from the visual streak of porcine eyes, which closely resemble the human macula. We show that retinae exposed to FH-deprived RPE cells show signs of retinal degeneration, with rod cells being the first cells to undergo degeneration. Moreover, via Raman analyses, we observed changes involving the mitochondria and lipid composition of the co-cultured retinae upon FH loss. Interestingly, the detrimental effects of FH loss in RPE cells on the neuroretina were independent of glial cell activation and external complement sources. Moreover, we show that the co-culture model is also suitable for human retinal explants, and we observed a similar trend when RPE cells deprived of FH were co-cultured with human retinal explants from a single donor eye. Our findings highlight the importance of RPE-derived FH for retinal homeostasis and provide a valuable model for AMD research.

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Light-dependent induction of Edn2 expression and attenuation of retinal pathology by endothelin receptor antagonists in Prominin-1- deficient mice

10.1101/2020.12.07.405308 ◽

2020 ◽

Author(s):

Yuka Kobayashi ◽

Shizuka Watanabe ◽

Manabu Shirai ◽

Chiemi Yamashiro ◽

Tadahiko Ogata ◽

...

Keyword(s):

Cell Death ◽

Retinal Degeneration ◽

Cell Activation ◽

Photoreceptor Cell ◽

Macular Dystrophy ◽

Endothelin Receptor Antagonists ◽

Endothelin Receptor ◽

Receptor Antagonists ◽

Causative Gene ◽

High Throughput Analysis

AbstractRetinitis pigmentosa (RP) and macular dystrophy (MD) are prevalent retinal degenerative diseases associated with gradual photoreceptor death. These diseases are often caused by genetic mutations that result in degeneration of the retina postnatally after it has fully developed. The Prominin-1 gene (Prom1) is a causative gene for RP and MD, and Prom1- knockout (KO) mice recapitulate key features of these diseases including light-dependent retinal degeneration and stenosis of retinal blood vessels. The mechanisms underlying progression of such degeneration have remained unknown, however. We here analysed early events associated with retinal degeneration in Prom1-KO mice. We found that photoreceptor cell death and glial cell activation occur between 2 and 3 weeks after birth. High-throughput analysis revealed that expression of the endothelin-2 gene (Edn2) was markedly up-regulated in the Prom1-deficient retina during this period. Expression of Edn2 was also induced by light stimulation in Prom1-KO mice that had been reared in the dark. Finally, treatment with endothelin receptor antagonists attenuated photoreceptor cell death, gliosis, and retinal vessel stenosis in Prom1-KO mice. Our findings suggest that inhibitors of endothelin signalling may delay the progression of RP and MD and therefore warrant further study as potential therapeutic agents for these diseases.

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Early manifestations and differential gene expression associated with photoreceptor degeneration in Prominin-1-deficient retina

Disease Models & Mechanisms ◽

10.1242/dmm.048962 ◽

2021 ◽

Author(s):

Yuka Kobayashi ◽

Shizuka Watanabe ◽

Agnes Ong Lee Chen ◽

Manabu Shirai ◽

Chiemi Yamashiro ◽

...

Keyword(s):

Gene Expression ◽

Cell Death ◽

Retinal Degeneration ◽

Cell Activation ◽

Photoreceptor Cell ◽

Retinal Vessel ◽

Macular Dystrophy ◽

Glial Cell Activation ◽

Retinal Blood Vessels ◽

Vessel Stenosis

Retinitis pigmentosa (RP) and macular dystrophy (MD) are characterized by gradual photoreceptor death in the retina and are often associated with genetic mutations including those in the Prominin-1 (Prom1) gene. Prom1-knockout (KO) mice recapitulate key features of these diseases including light-dependent retinal degeneration and constriction of retinal blood vessels. The mechanisms underlying such degeneration have remained unclear, however. We here analysed early events associated with retinal degeneration in Prom1-KO mice. We found that photoreceptor cell death and glial cell activation occur between 2 and 3 weeks after birth. Whereas gene expression was not affected at 2 weeks, the expression of several genes was altered at 3 weeks in the Prom1-KO retina, with the expression of that for Endothelin-2 (Edn2) being markedly up-regulated. Expression of Edn2 was also induced by light stimulation in Prom1-KO mice reared in the dark. Treatment with endothelin receptor antagonists attenuated photoreceptor cell death, gliosis, and retinal vessel stenosis in Prom1-KO mice. Our findings thus reveal early manifestations of retinal degeneration in a model of RP/MD and suggest potential therapeutic agents for these diseases.

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FH loss in RPE cells causes retinal degeneration in a human RPE-porcine retinal explant co-culture model

10.1101/2021.07.26.453778 ◽

2021 ◽

Author(s):

Angela Armento ◽

Aparna Murali ◽

Julia Marzi ◽

Blanca Arango-Gonzalez ◽

Ellen Kilger ◽

...

Keyword(s):

Retinal Degeneration ◽

Cell Activation ◽

The Elderly ◽

Factor H ◽

Age Related Macular Degeneration ◽

Complement Factor ◽

Rpe Cells ◽

Age Related ◽

Culture Model ◽

Retinal Explants

Age-related Macular degeneration (AMD) is a degenerative disease of the macula affecting the elderly population. Treatment op-tions are limited, partly due to the lack of understanding of AMD pathology and the sparse availability of research models, that replicate the complexity of the human macula and the intricate interplay of the genetic, aging and life-style risk factors contrib-uting to AMD. One of the main genetic risks associated with AMD is located on Complement Factor H (CFH) gene, leading to an amino acid substitution in the FH protein (Y402H). However, the mechanism of how this FH variant promotes the onset of AMD remains unclear. Previously, we have shown that FH deprivation in RPE cells, via CFH silencing, leads to increased inflammation, metabolic impairment and vulnerability towards oxidative stress. In this study, we established a novel co-culture model comprised of CFH silenced RPE cells and porcine retinal explants derived from the visual streak of the porcine eyes, closely resembling the human macula. We show that retinae exposed to FH-deprived RPE cells show signs of retinal degeneration, with rod cells being the first cells to undergo degeneration. Moreover, via Raman analyses, we observe that the main changes involve the mitochondria and lipid composition of the co-cultured retinae upon FH loss. Interestingly, the detrimental effects of FH loss in RPE cells on the neuroretina were independent of glial cell activation and external complement sources. Moreover, we show that the co-culture model is also suitable for human retinal explants, and we observed a similar trend when RPE cells deprived of FH were co-cultured with human retinal explants from a single donor eye. Our findings highlight the importance of RPE derived FH for retinal homeostasis and provide a valuable model for AMD research.

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RNA Biological Characteristics at the Peak of Cell Death in Different Hereditary Retinal Degeneration Mutants

Frontiers in Genetics ◽

10.3389/fgene.2021.728791 ◽

2021 ◽

Vol 12 ◽

Author(s):

Chunling Wei ◽

Yan Li ◽

Xiaoxiao Feng ◽

Zhulin Hu ◽

François Paquet-Durand ◽

...

Keyword(s):

Cell Death ◽

Transcription Factors ◽

Network Analysis ◽

Retinal Degeneration ◽

Cell Activation ◽

Molecular Mechanisms ◽

Photoreceptor Cell ◽

Predictive Biomarkers ◽

Retinal Tissue ◽

Inherited Retinal Degeneration

Purpose: The present work investigated changes in the gene expression, molecular mechanisms, and pathogenesis of inherited retinal degeneration (RD) in three different disease models, to identify predictive biomarkers for their varied phenotypes and to provide a better scientific basis for their diagnosis, treatment, and prevention.Methods: Differentially expressed genes (DEGs) between retinal tissue from RD mouse models obtained during the photoreceptor cell death peak period (Pde6brd1 at post-natal (PN) day 13, Pde6brd10 at PN23, Prphrd2 at PN29) and retinal tissue from C3H wild-type mice were identified using Illumina high-throughput RNA-sequencing. Co-expression gene modules were identified using a combination of GO and KEGG enrichment analyses and gene co-expression network analysis. CircRNA-miRNA-mRNA network interactions were studied by genome-wide circRNA screening.Results:Pde6brd1, Pde6brd10, and Prphrd2 mice had 1,926, 3,096, and 375 DEGs, respectively. Genes related to ion channels, stress, inflammatory processes, tumor necrosis factor (TNF) production, and microglial cell activation were up-regulated, while genes related to endoplasmic reticulum regulation, metabolism, and homeostasis were down-regulated. Differential expression of transcription factors and non-coding RNAs generally implicated in other human diseases was detected (e.g., glaucoma, diabetic retinopathy, and inherited retinal degeneration). CircRNA-miRNA-mRNA network analysis indicated that these factors may be involved in photoreceptor cell death. Moreover, excessive cGMP accumulation causes photoreceptor cell death, and cGMP-related genes were generally affected by different pathogenic gene mutations.Conclusion: We screened genes and pathways related to photoreceptor cell death. Additionally, up-stream regulatory factors, such as transcription factors and non-coding RNA and their interaction networks were analyzed. Furthermore, RNAs involved in RD were functionally annotated. Overall, this study lays a foundation for future studies on photoreceptor cell death mechanisms.

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Immunogold labeling of the calcium binding protein synexin in isolated adrenal chromaffin granules and chromaffin cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100162326 ◽

1990 ◽

Vol 48 (3) ◽

pp. 952-953

Author(s):

Gemma A.J. Kuijpers ◽

Harvey B. Pollard

Keyword(s):

Adrenal Medulla ◽

Calcium Binding ◽

Chromaffin Cells ◽

Cell Activation ◽

Structural Information ◽

Dependent Manner ◽

Chromaffin Granules ◽

Immuno Electron Microscopy ◽

Ultrathin Sections ◽

Adrenal Chromaffin

Exocytotic fusion of granules in the adrenal medulla chromaffin cell is triggered by a rise in the concentration of cytosolic Ca2+ upon cell activation. The protein synexin, annexin VII, was originally found in the adrenal medulla and has been shown to cause aggregation and to support fusion of chromaffin granules in a Ca2+-dependent manner. We have previously suggested that synexin may there fore play a role in the exocytotic fusion process. In order to obtain more structural information on synexin, we performed immuno-electron microscopy on frozen ultrathin sections of both isolated chromaffin granules and chromaffin cells.Chromaffin granules were isolated from bovine adrenal medulla, and synexin was isolated from bovine lung. Granules were incubated in the presence or absence of synexin (24 μg per mg granule protein) and Ca2+ (1 mM), which induces maximal granule aggregation, in 0.3M sucrose-40m MMES buffer(pH 6.0). Granules were pelleted, washed twice in buffer without synexin and fixed with 2% glutaraldehyde- 2% para formaldehyde in 0.1 M phosphate buffer (GA/PFA) for 30 min. Chromaffin cells were isolated and cultured for 3-5 days, and washed and incubated in Krebs solution with or without 20 uM nicotine. Cells were fixed 90 sec after on set of stimulation with GA/PFA for 30 min. Fixed granule or cell pellets were washed, infiltrated with 2.3 M sucrose in PBS, mounted and frozen in liquid N2.

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