scholarly journals miR-126 Mimic Counteracts the Increased Secretion of VEGF-A Induced by High Glucose in ARPE-19 Cells

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Roberta Sanguineti ◽  
Alessandra Puddu ◽  
Massimo Nicolò ◽  
Carlo Enrico Traverso ◽  
Renzo Cordera ◽  
...  
Keyword(s):  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Pigment Epithelium Cell ◽  
Diabetic Complication ◽  
Negative Control ◽  
Mrna Levels ◽  
Vascular Endothelial ◽  
Rpe Cells ◽  
Endothelial Growth Factor

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.

Retinoprotective Effects of Crocin and Crocetin via Anti-angiogenic Mechanism in High Glucose-Induced Human Retinal Pigment Epithelium Cells

2021 ◽  
Vol 14 ◽  
Author(s):  
Samaneh Sepahi ◽  
Zahra-Soheila Soheili ◽  
Jalil Tavakkol-Afshari ◽  
Soghra Mehri ◽  
Seyedeh Maryam Hosseini ◽  
...  
Keyword(s):  
Gene Expression ◽  
Vascular Endothelial Growth Factor ◽  
High Glucose ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Vascular Endothelial ◽  
Rpe Cells ◽  
Treatment Groups ◽  
Protein Levels ◽  
Endothelial Growth Factor

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.

scholarly journals A human model of Batten disease shows role of CLN3 in phagocytosis at the photoreceptor–RPE interface

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Cynthia Tang ◽  
Jimin Han ◽  
Sonal Dalvi ◽  
Kannan Manian ◽  
Lauren Winschel ◽  
...  
Keyword(s):  
Photoreceptor Cell ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Cell Loss ◽  
Human Model ◽  
Lysosomal Storage ◽  
Rpe Cells ◽  
Cln3 Disease

AbstractMutations in CLN3 lead to photoreceptor cell loss in CLN3 disease, a lysosomal storage disorder characterized by childhood-onset vision loss, neurological impairment, and premature death. However, how CLN3 mutations cause photoreceptor cell death is not known. Here, we show that CLN3 is required for phagocytosis of photoreceptor outer segment (POS) by retinal pigment epithelium (RPE) cells, a cellular process essential for photoreceptor survival. Specifically, a proportion of CLN3 in human, mouse, and iPSC-RPE cells localized to RPE microvilli, the site of POS phagocytosis. Furthermore, patient-derived CLN3 disease iPSC-RPE cells showed decreased RPE microvilli density and reduced POS binding and ingestion. Notably, POS phagocytosis defect in CLN3 disease iPSC-RPE cells could be rescued by wild-type CLN3 gene supplementation. Altogether, these results illustrate a novel role of CLN3 in regulating POS phagocytosis and suggest a contribution of primary RPE dysfunction for photoreceptor cell loss in CLN3 disease that can be targeted by gene therapy.

scholarly journals Effects of refraction and axial length on the development and progression of diabetic retinopathy

2021 ◽  
Vol 21 (4) ◽  
pp. 205-209
Author(s):  
M.M. Bikbov ◽  
◽  
O.I. Orenburkina ◽  
A.E. Babushkin ◽  
A.A. Fakhretdinova ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Diabetic Retinopathy ◽  
Growth Factor ◽  
Axial Length ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Vascular Endothelial ◽  
Keywords Diabetic Retinopathy ◽  
Eye Disorders ◽  
Endothelial Growth Factor

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.

JAM-C maintains VEGR2 expression to promote retinal pigment epithelium cell survival under oxidative stress

2017 ◽  
Vol 117 (04) ◽  
pp. 750-757
Author(s):  
Xin Jia ◽  
Chen Zhao ◽  
Qishan Chen ◽  
Yuxiang Du ◽  
Lijuan Huang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Retinal Pigment Epithelium ◽  
Cell Survival ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Pigment Epithelium Cell ◽  
Photoreceptor Cells ◽  
Rpe Cells

SummaryJunctional adhesion molecule-C (JAM-C) has been shown to play critical roles during development and in immune responses. However, its role in adult eyes under oxidative stress remains poorly understood. Here, we report that JAM-C is abundantly expressed in adult mouse retinae and choroids in vivo and in cultured retinal pigment epithelium (RPE) and photoreceptor cells in vitro. Importantly, both JAM-C expression and its membrane localisation are downregulated by H2O2-induced oxidative stress. Under H2O2-induced oxidative stress, JAM-C is critically required for the survival of human RPE cells. Indeed, loss of JAM-C by siRNA knockdown decreased RPE cell survival. Mechanistically, we show that JAM-C is required to maintain VEGFR2 expression in RPE cells, and VEGFR2 plays an important role in keeping the RPE cells viable since overexpression of VEGFR2 partially restored impaired RPE survival caused by JAM-C knockdown and increased RPE survival. We further show that JAM-C regulates VEGFR2 expression and, in turn, modulates p38 phosphorylation. Together, our data demonstrate that JAM-C plays an important role in maintaining VEGR2 expression to promote RPE cell survival under oxidative stress. Given the vital importance of RPE in the eye, approaches that can modulate JAM-C expression may have therapeutic values in treating diseases with impaired RPE survival.

scholarly journals Mitochondrial Ceramide Effects on the Retinal Pigment Epithelium in Diabetes

2020 ◽  
Vol 21 (11) ◽  
pp. 3830 ◽  
Author(s):  
Yan Levitsky ◽  
Sandra S. Hammer ◽  
Kiera P. Fisher ◽  
Chao Huang ◽  
Travan L. Gentles ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Mitochondrial Function ◽  
High Glucose ◽  
Citrate Synthase ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Intercellular Adhesion Molecule ◽  
Early Event ◽  
Rpe Cells

Mitochondrial damage in the cells comprising inner (retinal endothelial cells) and outer (retinal pigment epithelium (RPE)) blood–retinal barriers (BRB) is known to precede the initial BRB breakdown and further histopathological abnormalities in diabetic retinopathy (DR). We previously demonstrated that activation of acid sphingomyelinase (ASM) is an important early event in the pathogenesis of DR, and recent studies have demonstrated that there is an intricate connection between ceramide and mitochondrial function. This study aimed to determine the role of ASM-dependent mitochondrial ceramide accumulation in diabetes-induced RPE cell damage. Mitochondria isolated from streptozotocin (STZ)-induced diabetic rat retinas (7 weeks duration) showed a 1.64 ± 0.29-fold increase in the ceramide-to-sphingomyelin ratio compared to controls. Conversely, the ceramide-to-sphingomyelin ratio was decreased in the mitochondria isolated from ASM-knockout mouse retinas compared to wild-type littermates, confirming the role of ASM in mitochondrial ceramide production. Cellular ceramide was elevated 2.67 ± 1.07-fold in RPE cells derived from diabetic donors compared to control donors, and these changes correlated with increased gene expression of IL-1β, IL-6, and ASM. Treatment of RPE cells derived from control donors with high glucose resulted in elevated ASM, vascular endothelial growth factor (VEGF), and intercellular adhesion molecule 1 (ICAM-1) mRNA. RPE from diabetic donors showed fragmented mitochondria and a 2.68 ± 0.66-fold decreased respiratory control ratio (RCR). Treatment of immortalized cell in vision research (ARPE-19) cells with high glucose resulted in a 25% ± 1.6% decrease in citrate synthase activity at 72 h. Inhibition of ASM with desipramine (15 μM, 1 h daily) abolished the decreases in metabolic functional parameters. Our results are consistent with diabetes-induced increase in mitochondrial ceramide through an ASM-dependent pathway leading to impaired mitochondrial function in the RPE cells of the retina.

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