Showing 3 results for Retinal Pigment Epithelium
F. Babapoura , F. Yazdian , F. Tabandeh ,
Volume 9, Issue 1 (1-2018)
Abstract
Aims: Age-Related Macular Degeneration (AMD) is one of the biggest causes of vision loss after 50 years of age in the world. AMD disease destroys the retinal pigment cells. Retinal tissue engineering provides a suitable environment for the growth of retinal pigment epithelium cells using different scaffolds. These scaffolds may cause interior pressure changes in eyes and thus, causes disease of the separation of pigment and retinal epithelial cells. Therefore, the purpose of this study was to simulate gelatin, gelatin-chitosan and poly-caprolactone scaffolds in the retina and compare the pressure gradient and the effect of thickness on the pressure gradient.
Materials & Methods: In the present experimental study, in the first stage, three gelatin, gelatin-chitosan and poly-caprolactone scaffolds were simulated to examine the average scaffold pressure using COMSOL 5.1.1 software and Darcy law. In the next step, a gelatin-chitosan scaffold with thicknesses of 10 and 20 micron was simulated with Darcy law, to examine the effect of thickness on average pressure.
Findings: The output pressure of the gelatin scaffold was calculated as 308.800Pa Which was less than the pressure level of the caroid layer And it was less than the output pressure of other scaffolds. The average pressure of gelatin-chitosan scaffold with thicknesses of 10 and 20 micron was 1997.31 and 2003.13 respectively in the last step.
Conclusion: The gelatin scaffold produces a moderate lower pressure than the gelatin-chitosan scaffold and poly-caprolactone in the retina and it is more suitable than other scaffolds. In the simulation of gelatin-chitosan scaffold, increasing the thickness causes increased pressure and retinal impairment.
F. Shariari, Sh. Moradi, M. Totonchi, L. Satarian, S.j. Mowla, H. Baharvand,
Volume 10, Issue 3 (9-2019)
Abstract
Aims: The retinal pigment epithelium cells (RPE) have crucial roles in the health and functionality of retina. Any damage or dysfunction of these cells can lead to severe retinopathies. Identification of signaling pathways and biological processes involved in RPE differentiation can be useful in devising more robust therapeutic approaches.
Materials and Methods: In the present study, we used the intersection of three online prediction databases and their ::union:: with one experimental database to select microRNAs gene targets. Next, by the intersect of the targeted genes with an increase in their expression in epithelial to mesenchymal transition (EMT) of RPE cells, we tried to build a microRNA-mRNA integrative network. Further, several pathway analyses tools were used to perform a more accurate and comprehensive analysis of the signaling pathways and biological processes being regulated by selected miRs in the EMT of the RPE cells.
Findings: Our study revealed that among the 3406 genes being upregulated over the course of EMT in RPE cells, adj p-value≤0.05, fold change≥1.5, 93 genes were miR-204-5p and miR 211-5p target genes. Further analysis of the obtained target gene list demonstrated that these two microRNAs are mostly involved in maintaining RPE cells from going through EMT via regulation of cell adhesion and secretion subnetworks and also MAPK and TGF-β1 signaling pathways while preserving cells from apoptosis and neuronal fates.
Conclusion: This study indicated that miR-204-5p and miR 211-5p are involved in protecting RPE cells from EMT and reinforce their epithelial cell identity.
Volume 16, Issue 3 (12-2013)
Abstract
Objective: Human retinal pigment epithelium (hRPE) is a cell monolayer located in the outer part of the retina that is in contact with photoreceptors. In many diseases RPE cells damage. One way for treating this disease is the implantation of intact instead of damaged cells. For this reason different types of substrates have been used for cell cultivation. This study has used alginate and a blend of alginate/gelatin (A/G) to study RPE cell growth.
Methods: We prepared alginate solutions in concentrations of 1% and 2% (w/v) in water and DMEM/F12. The solutions were infused into each well of 6-well micro plates until a uniform culture substrate that had a 1 mm thickness was generated. Passage-4 hRPE cells were cultivated on the substrate and the cell characteristics studied. hRPE cells did not adhere to alginate in DMEM/F12 and did not exhibit interaction with alginate substrate. For this reason A/G solutions at concentrations of 1% and 2% (w/v) in water were prepared. We prepared A/G blends at weight ratios of: 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, and 80:20. These blends were infused into each well of 6-well plates until the appropriate 1 mm thickness of A/G was achieved. Isolated hRPE cells were cultured on synthetic substrate after which we studied the cells' characteristics.
Result: hRPE cell generated adhesive colonies on the A/G substrate. In all studied combinations of A/G, the diffused hRPE cells formed a monolayer under the substrate sheets. However the A/G 20:80 ratio had cell growth in the upper face of the substrate. hRPE survived indefinitely on A/G substrate. After the cells were re-cultured on polystyrene, they showed general morphological features of normal hRPE cells.
Conclusion: The A/G blend at a 20:80 ratio was chosen to be used for future studies.
