scholarly journals Regulation of Matrix Metalloproteinase-2 Secretion from Scleral Fibroblasts and Retinal Pigment Epithelial Cells by miR-29a

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Yingjie Zhang ◽  
Dan-Ning Hu ◽  
Yi Zhu ◽  
Hao Sun ◽  
Ping Gu ◽  
...  
Keyword(s):  
Matrix Metalloproteinase ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Pigment Epithelial Cells ◽  
Cell Counting ◽  
Matrix Metalloproteinase 2 ◽  
Mrna Levels ◽  
Myopia Progression ◽  
Rpe Cells ◽  
Cell Expression

Purpose. To identify an effective method to prevent myopia progression by characterizing the regulation of matrix metalloproteinase- (MMP-) 2 expression and its secretion from scleral fibroblasts and retinal pigment epithelium (RPE) cells by miR-29a. Methods. The effects of miR-29a on the growth of scleral fibroblasts and RPE cells were assessed using the cell counting kit-8. The changes in MMP-2 mRNA levels in scleral fibroblasts and RPE cells after transfection with miR-29a mimics or inhibitor were measured by quantitative PCR. Enzyme-linked immunosorbent assays were used to determine the changes in MMP-2 secretion from scleral fibroblasts and RPE cells after transfection with miR-29a mimics or inhibitor. Results. The miR-29a mimics or inhibitor did not significantly alter the growth of scleral fibroblasts or RPE cells at 24, 48, or 72 hours after transfection. MMP-2 mRNA levels were significantly decreased in scleral fibroblasts and RPE cells transfected with the miR-29a mimics. The secretion of MMP-2 by scleral fibroblasts and RPE cells was significantly decreased in cells transfected with the miR-29a mimics. Conclusions. Suppression of scleral fibroblast and RPE cell expression and secretion of MMP-2 by miR-29a can be used as a therapeutic target for the prevention and treatment of myopia.

Release of ATP from retinal pigment epithelial cells involves both CFTR and vesicular transport

2005 ◽  
Vol 288 (1) ◽  
pp. C132-C140 ◽  
Author(s):  
David Reigada ◽  
Claire H. Mitchell
Keyword(s):  
Epithelial Cells ◽  
Apical Membrane ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Vesicular Transport ◽  
Atp Release ◽  
Retinal Pigment Epithelial Cells ◽  
Subretinal Space ◽  
Transport Pathways ◽  
Rpe Cells

The retinal pigment epithelium (RPE) faces the photoreceptor outer segments and regulates the composition of the interstitial subretinal space. ATP enhances fluid movement from the subretinal space across the RPE. RPE cells can themselves release ATP, but the mechanisms and polarity of this release are unknown. The RPE expresses the cystic fibrosis transmembrane conductance regulator (CFTR), and CFTR is associated with ATP release in other epithelial cells. However, an increasing number of reports have suggested that the exocytotic pathway contributes to release. In the present study, we examined the involvement of CFTR and the vesicular pathway in ATP release from RPE cells. Release from cultured human ARPE-19 cells and across the apical membrane of fresh bovine RPE cells in an eyecup was studied. A cAMP cocktail to activate CFTR triggered ATP release from fresh and cultured RPE cells. Release from both RPE preparations was largely prevented by the broad-acting blocker glibenclamide and the specific thiazolidinone CFTR inhibitor CFTR-172. The block by CFTR-172 was enhanced by preincubation and prevented ATP release with 3.5 μM IC50. The rise in intracellular Ca2+ accompanying hypotonic challenge was prevented by CFTR-172. The vesicular transport inhibitor brefeldin A prevented ATP release after stimulation with both hypotonic and cAMP conditions, suggesting vesicular insertion was also involved. These results show an intimate involvement of CFTR in ATP release from RPE cells which can autostimulate receptors on the apical membrane to modify Ca2+ signaling. The requirement for both CFTR and vesicular transport pathways suggests vesicular insertion of CFTR may underlie the release of ATP.

scholarly journals Isolation of Bovine Retinal Pigment Epithelial Cells Using Adhesion to Agarose: Demonstration of Cellular and Regional Heterogeneity

2003 ◽  
Vol 51 (1) ◽  
pp. 121-124 ◽  
Author(s):  
Eleonore Fröhlich ◽  
Elke Maier ◽  
Christian Klessen
Keyword(s):  
Enzymatic Activity ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Histochemical Staining ◽  
Retinal Pigment Epithelial Cells ◽  
Isolated Cells ◽  
Regional Heterogeneity ◽  
Rpe Cells ◽  
A New Technique

The retinal pigment epithelium (RPE) shows cell heterogeneity in morphology and enzymatic activity. Routine isolation procedures for RPE cells may reduce enzymatic activity and prevent the quantification of regional enzymatic differences in vivo. We developed a new technique for the isolation of RPE cells based on adhesion of the cells to agarose. The morphology of the isolated cells resembled that of RPE cells in vivo. The cells were viable in the dye exclusion test and showed a histochemical staining pattern as RPE cells in vivo. With this technique, quantitative regional differences in the enzymatic activities were detected.

scholarly journals Fallopia Japonica and Prunella Vulgaris Inhibit Myopia Progression by Suppressing Akt and NFκB Mediated Inflammatory Reactions

2021 ◽  
Author(s):  
Chia-Hung Lin ◽  
Chih-Sheng Chen ◽  
Yao-Chien Wang ◽  
En-Shyh Lin ◽  
Ching-Yao Chang ◽  
...  
Keyword(s):  
Transforming Growth Factor Beta ◽  
Axial Length ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Retinal Pigment Epithelial Cell ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Myopia Progression ◽  
Rpe Cells ◽  
Expression Levels

The increased global incidence of myopia requires the establishment of therapeutic approaches. Previous studies have suggested that inflammation plays an important role in the development and progression of myopia. We used human retinal pigment epithelial cell to study the molecular mechanisms on how FJE and PVE lowering the inflammation of the eye. The effect of FJE and PVE in MFD induced hamster model and explore the role of inflammation cytokines in myopia. Expression levels of IL-6, IL-8, and TNF-α were upregulated in retinal pigment epithelium (RPE) cells treated with IL-6 and TNF-α. FJ extract (FJE) + PV extract (PVE) reduced IL-6, IL-8, and TNF-α expression in RPE cells. Furthermore, FJE and PVE inhibited inflammation by attenuating the phosphorylation of protein kinase B (AKT), and nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) pathway. In addition, we report two resveratrol + ursolic acid compounds from FJ and PV and their inhibitory activities against IL-6, IL-8, and TNF-α expression levels in RPE cells treated with IL-6 and TNF-α. FJE, PVE, and FJE + PVE were applied to MFD hamsters and their axial length was measured after 21 days. The axial length showed statistically significant differences between phosphate-buffered saline- and FJE-, PVE-, and FJE + PVE-treated MFD eyes. FJE + PVE suppressed expressions of IL-6, IL-8, and TNF-α. They also inhibited myopia-related transforming growth factor-beta (TGF)-β1, matrix metalloproteinase (MMP)-2, and NF-κB expression while increasing type Ⅰ collagen expression. Overall, these results suggest that FJE + PVE may have a therapeutic effect on myopia and be used as a potential treatment option.

scholarly journals Absence of iron-regulatory protein Hfe results in hyperproliferation of retinal pigment epithelium: role of cystine/glutamate exchanger

2009 ◽  
Vol 424 (2) ◽  
pp. 243-252 ◽  
Author(s):  
Jaya P. Gnana-Prakasam ◽  
Muthusamy Thangaraju ◽  
Kebin Liu ◽  
Yonju Ha ◽  
Pamela M. Martin ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Retinal Pigment Epithelium ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Critical Role ◽  
Ammonium Citrate ◽  
Ferric Ammonium Citrate ◽  
Mrna Levels ◽  
Wild Type ◽  
Rpe Cells

Haemochromatosis is an iron-overload disorder with age-dependent oxidative stress and dysfunction in a variety of tissues. Mutations in HFE (histocompatability leucocyte antigen class I-like protein involved in iron homoeostasis) are responsible for most cases of haemochromatosis. We demonstrated recently that HFE is expressed exclusively in the basal membrane of RPE (retinal pigment epithelium). In the present study, we used Hfe−/− mice to examine ferritin levels (an indirect readout for iron levels) and morphological changes in retina. We found increased ferritin accumulation in retina in 18-month-old, but not in 2-month-old, mice with considerable morphological damage compared with age-matched controls. The retinal phenotype included hypertrophy and hyperplasia of RPE. RPE cells isolated from Hfe−/− mice exhibited a hyperproliferative phenotype. We also compared the gene expression profile between wild-type and Hfe−/− RPE cells by microarray analysis. These studies showed that many cell cycle-related genes were differentially regulated in Hfe−/− RPE cells. One of the genes up-regulated in Hfe−/− RPE cells was Slc7a11 (where Slc is solute carrier) which codes for the ‘transporter proper’ xCT in the heterodimeric cystine/glutamate exchanger (xCT/4F2hc). This transporter plays a critical role in cellular glutathione status and cell-cycle progression. We confirmed the microarrray data by monitoring xCT mRNA levels by RT (reverse transcription)–PCR and also by measuring transport function. We also found increased levels of glutathione and the transcription factor/cell-cycle promoter AP1 (activator protein 1) in Hfe−/− RPE cells. Wild-type mouse RPE cells and human RPE cell lines, when loaded with iron by exposure to ferric ammonium citrate, showed increased expression and activity of xCT, reproducing the biochemical phenotype observed with Hfe−/− RPE cells.

scholarly journals Effects of Lycium barbarum polysaccharide on the photoinduced autophagy of retinal pigment epithelium cells

2022 ◽  
Vol 15 (1) ◽  
pp. 23-30
Author(s):  
Yuan-Yuan Gao ◽  
◽  
Jie Huang ◽  
Wu-Jun Li ◽  
Yang Yu ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Cell Counting ◽  
High Dose ◽  
Lycium Barbarum ◽  
Rpe Cells ◽  
Expression Levels ◽  
Lycium Barbarum Polysaccharide

AIM: To investigate the relationship between autophagy and apoptosis in photoinduced injuries in retinal pigment epithelium (RPE) cells and how Lycium barbarum polysaccharide (LBP) contributes to the increased of RPE cells to photoinduced autophagy. METHODS: In vitro cultures of human RPE strains (ARPE-19) were prepared and randomly divided into the blank control, model, low-dose LBP, middle-dose LBP, high-dose LBP, and 3-methyladenine (3MA) groups. The viability of the RPE cells and apoptosis levels in each group were tested through cell counting kit-8 (CCK8) method with a flow cytometer (Annexin V/PI double staining technique). The expression levels of LC3II, LC3I, and P62 proteins were detected with the immunofluorescence method. The expression levels of beclin1, LC3, P62, PI3K, P-mTOR, mTOR, P-Akt, and Akt proteins were tested through Western blot. RESULTS: LBP considerably strengthens cell viability and inhibits the apoptosis of RPE cells after photoinduction. The PI3K/Akt/mTOR signal pathway is activated because of the upregulation of the phosphorylation levels of Akt and mTOR proteins, and thus autophagy is inhibited. CONCLUSION: LBP can inhibit the excessive autophagy in RPE cells by activating the PI3K/Akt/mTOR signaling pathways and thereby protect RPE cells from photoinduced injuries.

scholarly journals Hypoxia-induced metabolic stress in retinal pigment epithelial cells is sufficient to induce photoreceptor degeneration

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Toshihide Kurihara ◽  
Peter D Westenskow ◽  
Marin L Gantner ◽  
Yoshihiko Usui ◽  
Andrew Schultz ◽  
...  
Keyword(s):  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Metabolic Stress ◽  
Retinal Pigment Epithelial Cells ◽  
Age Related Macular Degeneration ◽  
Photoreceptor Degeneration ◽  
Rpe Cells ◽  
Glucose And Lipid Metabolism ◽  
Age Related ◽  
Cellular Stresses

Photoreceptors are the most numerous and metabolically demanding cells in the retina. Their primary nutrient source is the choriocapillaris, and both the choriocapillaris and photoreceptors require trophic and functional support from retinal pigment epithelium (RPE) cells. Defects in RPE, photoreceptors, and the choriocapillaris are characteristic of age-related macular degeneration (AMD), a common vision-threatening disease. RPE dysfunction or death is a primary event in AMD, but the combination(s) of cellular stresses that affect the function and survival of RPE are incompletely understood. Here, using mouse models in which hypoxia can be genetically triggered in RPE, we show that hypoxia-induced metabolic stress alone leads to photoreceptor atrophy. Glucose and lipid metabolism are radically altered in hypoxic RPE cells; these changes impact nutrient availability for the sensory retina and promote progressive photoreceptor degeneration. Understanding the molecular pathways that control these responses may provide important clues about AMD pathogenesis and inform future therapies.

Calcium-independent regulation of pigment granule aggregation and dispersion in teleost retinal pigment epithelial cells

1996 ◽  
Vol 109 (1) ◽  
pp. 33-43
Author(s):  
C. King-Smith ◽  
P. Chen ◽  
D. Garcia ◽  
H. Rey ◽  
B. Burnside
Keyword(s):  
Intracellular Calcium ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Pigment Granule ◽  
Retinal Pigment Epithelial Cells ◽  
Rod Photoreceptor ◽  
Rpe Cells ◽  
Pigment Granules ◽  
Pigment Granule Migration

In the eyes of teleosts and amphibians, melanin pigment granules of the retinal pigment epithelium (RPE) migrate in response to changes in light conditions. In the light, pigment granules disperse into the cells' long apical projections, thereby shielding the rod photoreceptor outer segments and reducing their extent of bleach. In darkness, pigment granules aggregate towards the base of the RPE cells. In vitro, RPE pigment granule aggregation can be induced by application of nonderivatized cAMP, and pigment granule dispersion can be induced by cAMP washout. In previous studies based on RPE-retina co-cultures, extracellular calcium was found to influence pigment granule migration. To examine the role of calcium in regulation of RPE pigment granule migration in the absence of retinal influences, we have used isolated RPE sheets and dissociated, cultured RPE cells. Under these conditions depletion of extracellular or intracellular calcium ([Ca2+]o, [Ca2+]i) had no effect on RPE pigment granule aggregation or dispersion. Using the intracellular calcium dye fura-2 and a new dye, fura-pe3, to monitor calcium dynamics in isolated RPE cells, we found that [Ca2+]i did not change from basal levels when pigment granule aggregation was triggered by cAMP, or dispersion was triggered by cAMP washout. Also, no change in [Ca2+]i was detected when dispersion was triggered by cAMP washout in the presence of 10 microM dopamine, a treatment previously shown to enhance dispersion. In addition, elevation of [Ca2+]i by addition of ionomycin neither triggered pigment movements, nor interfered with pigment granule motility elicited by cAMP addition or washout. Since other studies have indicated that actin plays a role in both pigment granule dispersion and aggregation in RPE, our findings suggest that RPE pigment granule migration depends on an actin-based motility system that is not directly regulated by calcium.

scholarly journals Mitophagy in the Retinal Pigment Epithelium of Dry Age-Related Macular Degeneration Investigated in the NFE2L2/PGC-1α-/- Mouse Model

2020 ◽  
Vol 21 (6) ◽  
pp. 1976 ◽  
Author(s):  
Iswariyaraja Sridevi Gurubaran ◽  
Johanna Viiri ◽  
Ali Koskela ◽  
Juha M.T. Hyttinen ◽  
Jussi J. Paterno ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mouse Model ◽  
Macular Degeneration ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Pigment Epithelial Cells ◽  
Age Related Macular Degeneration ◽  
Double Knockout ◽  
Rpe Cells ◽  
Age Related

Increased oxidative stress and mitochondrial damage are observed in protein aggregation diseases, such as age-related macular degeneration (AMD). We have recently reported elevated levels of oxidative stress markers, damaged mitochondria, accumulating lysosomal lipofuscin and extracellular drusen-like structures in the retinal pigment epithelial cells (RPE) of the dry AMD-resembling NFE2L2/PGC1α double knockout (dKO) mouse model. Here, we provide evidence of a disturbance in the autolysosomal machinery handling mitochondrial clearance in the RPE cells of one-year-old NFE2L2/PGC1α-deficient mice. Confocal immunohistochemical analysis revealed an upregulation of autophagosome marker microtubule-associated proteins 1A/1B light chain 3B (LC3B) as well as numerous mitophagy markers, such as PTE-induced putative kinase 1 (PINK1) and E3 ubiquitin ligase (PARKIN) together with damaged mitochondria. However, we detected no evidence of increased autolysosome formation in transmission electron micrographs or of colocalization of lysosomal marker LAMP2 (lysosome-associated membrane protein 2) and the mitochondrial marker ATP synthase β in confocal micrographs. Interestingly, we observed an upregulation of late autolysosomal fusion Ras-related protein (Rab7) in the perinuclear space of RPE cells together with autofluorescence aggregates. Our results reveal that there is at least a relative decrease of mitophagy in the RPE cells of NFE2L2/PGC1α dKO mice. This further supports the hypothesis that mitophagy is a putative therapy target in AMD-like pathology.

scholarly journals The unusual microtubule polarity in teleost retinal pigment epithelial cells.

1988 ◽  
Vol 107 (4) ◽  
pp. 1461-1464 ◽  
Author(s):  
L L Troutt ◽  
B Burnside
Keyword(s):  
Retinal Pigment Epithelial ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Pigment Granule ◽  
Cell Types ◽  
Retinal Pigment Epithelial Cells ◽  
Light Onset ◽  
Rpe Cells ◽  
Microtubule Polarity ◽  
Pigment Epithelial Cells

In cells of the teleost retinal pigment epithelium (RPE), melanin granules disperse into the RPE cell's long apical projections in response to light onset, and aggregate toward the base of the RPE cell in response to dark onset. The RPE cells possess numerous microtubules, which in the apical projections are aligned longitudinally. Nocodazole studies have shown that pigment granule aggregation is microtubule-dependent (Troutt, L. L., and B. Burnside, 1988b Exp. Eye Res. In press.). To investigate further the mechanism of microtubule participation in RPE pigment granule aggregation, we have used the tubulin hook method to assess the polarity of microtubules in the apical projections of teleost RPE cells. We report here that virtually all microtubules in the RPE apical projections are uniformly oriented with plus ends toward the cell body and minus ends toward the projection tips. This orientation is opposite that found for microtubules of dermal melanophores, neurons, and most other cell types.

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