scholarly journals Human Induced Pluripotent Stem-Derived Retinal Pigment Epithelium (RPE) Cells Exhibit Ion Transport, Membrane Potential, Polarized Vascular Endothelial Growth Factor Secretion, and Gene Expression Pattern Similar to Native RPE

Stem Cells ◽  
2011 ◽  
Vol 29 (5) ◽  
pp. 825-835 ◽  
Author(s):  
Maria Kokkinaki ◽  
Niaz Sahibzada ◽  
Nady Golestaneh
2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Roberta Sanguineti ◽  
Alessandra Puddu ◽  
Massimo Nicolò ◽  
Carlo Enrico Traverso ◽  
Renzo Cordera ◽  
...  

Vascular endothelial growth factor-A (VEGF-A) has a pathologic role in microvascular diabetic complication, such as diabetic retinopathy (DR). miR-126 plays an important role in vascular development and angiogenesis by regulating the expression of VEGF-A. Since levels of miR-126 have been found downregulated in diabetes, this study is aimed at investigating whether hyperglycemia affects expression of miR-126 in a retinal pigment epithelium cell line. ARPE-19 cells were transfected with miR-126 inhibitor or with miR-126 mimic and the respective scramble negative control. After 24 hours, medium was replaced and cells were cultured for 24 hours in normal (CTR) or diabetic condition (HG). Then, we analyzed mRNA levels of miR-126, VEGF-A, PI3KR2, and SPRED1. We also evaluated protein amount of HIF-1α, PI3KR2, and SPRED1 and VEGF-A secretion. The results showed that exposure of ARPE-19 cells to HG significantly decreased miR-126 levels; mRNA levels of VEGF-A and PI3KR2 were inversely correlated with those of miR-126. Overexpression of miR-126 under HG restored HIF-1α expression and VEGF-A secretion to the level of CTR cells. These results indicate that reduced levels of miR-126 may contribute to DR progression by increasing expression of VEGF-A in RPE cells. In addition, we provide evidence that upregulation of miR-126 in RPE cells counteracts the rise of VEGF-A secretion induced by hyperglycemia. In conclusion, our data support a role of miR-126 mimic-approach in counteracting proangiogenic effects of hyperglycemia.


2021 ◽  
Vol 14 ◽  
Author(s):  
Samaneh Sepahi ◽  
Zahra-Soheila Soheili ◽  
Jalil Tavakkol-Afshari ◽  
Soghra Mehri ◽  
Seyedeh Maryam Hosseini ◽  
...  

Background: Diabetic retinopathy (DR) is one of the most common side effects of diabetes. We aimed to investigate the effects of crocin and crocetin (as a deglycosylated form of crocin in blood stream) in gene expression or protein levels of vascular endothelial growth factor (VEGF), vascular endothelial growth factor-receptor1 (VEGFR-1), matrix metalloproteinases2 (MMP-2), matrix metalloproteinases9 (MMP-9) and thrombospondin-2 (TSP-2) in high glucose cell culture media. Methods: The retinal pigment epithelium (RPE) cells were exposed to high glucose (HG, 30 mM glucose concentration) and normal glucose (NG, 24.5 mM mannitol + 5.5 mM glucose) for six days. RPE cells were treated in four treatment groups (crocin, crocetin, Bevacizumab, and crocin + Bevacizumab). Gene expressions were measured using quantitative real-time PCR, and proteins level was evaluated by western blot. Results: Findings showed that VEGF gene expression and protein level significantly decreased in all treatment groups. In addition, reduction in VEGFR1 gene expression was significantly higher in Bevacizumab and crocin + Bevacizumab groups than other groups. Only, crocin and crocetin could reduce the gene levels of MMP-2 and MMP-9. In addition, TSP-2 protein levels increased when HG cells were exposed crocin or crocin + Bevacizumab groups. Conclusion: Our data showed that crocin and crocetin have anti-VEGF function similar to Bevacizumab, act as an anti-angiogenic agent. Also, crocin and crocetin could decrease MMP-2 and MMP-9 gene levels, as inflammatory and angiogenesis factors. As a result, crocin and crocetin have protective effects against angiogenesis and inflammation in DR.


2021 ◽  
Vol 21 (4) ◽  
pp. 205-209
Author(s):  
M.M. Bikbov ◽  
◽  
O.I. Orenburkina ◽  
A.E. Babushkin ◽  
A.A. Fakhretdinova ◽  
...  

Eye disorders have a special place in diabetes since visual impairment has a significant effect on the quality of life. Therefore, determining risk factors and prognostic criteria for disease course are essential for developing strategies for early prevention of diabetic retinopathy (DR). This paper addresses studies on various aspects of DR in patients with myopia. It was demonstrated that DR arises, develops, and progresses in different ways under various axial lengths (AL). Thus, many authors report that DR barely occurs in high myopia. Some of them account for this phenomenon for poor blood circulation in a long myopic eye. Others refer to a significantly lower vascular endothelial growth factor (VEGF) concentration in longer eyes or eyes with myopic refraction. The third authors argue a focal disintegration of retinal pigment epithelium to eliminate metabolic end products through the choroid and sclera. As a result, neither acidosis nor venous congestion develops, and endothelial barrier function remains unaffected Keywords: diabetic retinopathy, myopia, axial length, vascular endothelial growth factor, emmetropia, hyperopia, diabetes. For citation: Bikbov M.M., Orenburkina O.I., Babushkin A.E., Fakhretdinova A.A. Effects of refraction and axial length on the development and progression of diabetic retinopathy. Russian Journal of Clinical Ophthalmology. 2021;21(4):205–209 (in Russ.). DOI: 10.32364/2311-7729- 2021-21-4-205-209.


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