scholarly journals High Glucose Disrupts Mitochondrial Morphology in Retinal Endothelial Cells

2010 ◽  
Vol 177 (1) ◽  
pp. 447-455 ◽  
Author(s):  
Kyle Trudeau ◽  
Anthony J.A. Molina ◽  
Wen Guo ◽  
Sayon Roy
Keyword(s):  
Endothelial Cells ◽  
High Glucose ◽  
Mitochondrial Morphology ◽  
Retinal Endothelial Cells

scholarly journals Downregulation of Drp1 and Fis1 Inhibits Mitochondrial Fission and Prevents High Glucose-Induced Apoptosis in Retinal Endothelial Cells

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1662
Author(s):  
Dongjoon Kim ◽  
Aravind Sankaramoorthy ◽  
Sayon Roy
Keyword(s):  
Endothelial Cells ◽  
Diabetic Retinopathy ◽  
High Glucose ◽  
Cell Apoptosis ◽  
Mitochondrial Fission ◽  
Confocal Imaging ◽  
Mitochondrial Morphology ◽  
Mitochondrial Fragmentation ◽  
Vascular Cell ◽  
Retinal Endothelial Cells

Diabetic retinopathy is a prevalent microvascular complication characterized by apoptotic vascular cell loss in the retina. Previous studies have shown that high glucose (HG)-induced mitochondrial fragmentation plays a critical role in promoting retinal vascular cell apoptosis. Here, we investigated whether downregulation of mitochondrial fission genes, Fis1 and Drp1, which are overexpressed in HG condition, prevents mitochondrial fragmentation, preserves mitochondrial function, and protects retinal endothelial cells from apoptosis. Rat retinal endothelial cells (RRECs) were grown in normal (5 mM glucose) or HG (30 mM glucose) medium; in parallel, cells grown in HG medium were transfected with either Fis1 siRNA or Drp1 siRNA, or both siRNAs in combination, or scrambled siRNA as control. Live-cell confocal imaging showed decreased mitochondrial fission in cells transfected with Fis1 siRNA or Drp1 siRNA concomitant with reduced TUNEL-positive cells and a decrease in the expression of pro-apoptotic proteins, Bax and cleaved caspase 3, under HG condition. Importantly, the combined siRNA approach against Fis1 and Drp1 prevented HG-induced changes in the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR). The findings from this study indicate that reducing HG-induced overexpression of mitochondrial fission genes preserves mitochondrial morphology and prevents retinal vascular cell apoptosis associated with diabetic retinopathy.

scholarly journals High Glucose-Induced Apoptosis Is Linked to Mitochondrial Connexin 43 Level in RRECs: Implications for Diabetic Retinopathy

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3102
Author(s):  
Aravind Sankaramoorthy ◽  
Sayon Roy
Keyword(s):  
Endothelial Cells ◽  
Diabetic Retinopathy ◽  
High Glucose ◽  
Connexin 43 ◽  
Caspase 3 ◽  
Vision Loss ◽  
Mitochondrial Morphology ◽  
Mitochondrial Fragmentation ◽  
Retinal Endothelial Cells ◽  
Induced Apoptosis

Diabetic retinopathy (DR) is one of the most common causes of vision loss and blindness among the working-age population. High glucose (HG)-induced decrease in mitochondrial connexin 43 (mtCx43) level is known to promote mitochondrial fragmentation, cytochrome c release, and apoptosis in retinal endothelial cells associated with DR. In this study, we investigated whether counteracting HG-induced decrease in mtCx43 level would preserve mitochondrial integrity and prevent apoptosis. Rat retinal endothelial cells (RRECs) were grown in normal (N; 5 mM glucose) or HG (30 mM glucose) medium for 7 days. In parallel, cells grown in HG were transfected with Cx43 plasmid, or empty vector (EV), as control. Western blot (WB) analysis showed a significant decrease in mtCx43 level concomitant with increased cleaved caspase-3, Bax, cleaved PARP, and mitochondrial fragmentation in cells grown in HG condition compared to those grown in N medium. When cells grown in HG were transfected with Cx43 plasmid, mtCx43 level was significantly increased and resulted in reduced cleaved caspase-3, Bax, cleaved PARP and preservation of mitochondrial morphology with a significant decrease in the number of TUNEL-positive cells compared to those grown in HG alone. Findings from the study indicate a novel role for mtCx43 in regulating apoptosis and that maintenance of mtCx43 level could be useful in preventing HG-induced apoptosis by reducing mitochondrial fragmentation associated with retinal vascular cell loss in DR.

scholarly journals Sulodexide reduces glucose induced senescence in human retinal endothelial cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Gericke ◽  
K. Suminska-Jasińska ◽  
A. Bręborowicz
Keyword(s):  
Endothelial Cells ◽  
High Glucose ◽  
Glucose Concentration ◽  
Chronic Exposure ◽  
Replicative Senescence ◽  
Population Doubling ◽  
Population Doubling Time ◽  
High Glucose Concentration ◽  
Retinal Endothelial Cells

AbstractChronic exposure of retinal endothelium cells to hyperglycemia is the leading cause of diabetic retinopathy. We evaluated the effect of high glucose concentration on senescence in human retinal endothelial cells (HREC) and modulation of that effect by Sulodexide. Experiments were performed on HREC undergoing in vitro replicative senescence in standard medium or medium supplemented with glucose 20 mmol/L (GLU) or mannitol 20 mnol/L (MAN). Effect of Sulodexide 0.5 LRU/mL (SUL) on the process of HREC senescence was studied. Glucose 20 mmol/L accelerates senescence of HREC: population doubling time (+ 58%, p < 0.001) β-galactosidase activity (+ 60%, p < 0.002) intracellular oxidative stress (+ 65%, p < 0.01), expression of p53 gene (+ 118%, p < 0.001). Senescent HREC had also reduced transendothelial electrical resistance (TEER) (− 30%, p < 0.001). Mannitol 20 mmol/L used in the same scenario as glucose did not induce HREC senescence. In HREC exposed to GLU and SUL, the senescent changes were smaller. HREC, which became senescent in the presence of GLU, demonstrated higher expression of genes regulating the synthesis of Il6 and VEGF-A, which was reflected by increased secretion of these cytokines (IL6 + 125%, p < 0.001 vs control and VEGF-A + 124% p < 0.001 vs control). These effects were smaller in the presence of SUL, and additionally, an increase of TEER in the senescent HREC was observed. Chronic exposure of HREC to high glucose concentration in medium accelerates their senescence, and that process is reduced when the cells are simultaneously exposed to Sulodexide. Additionally, Sulodexide decreases the secretion of IL6 and VEGF-A from senescent HREC and increases their TEER.

scholarly journals Distinct downstream signaling and the roles of VEGF and PlGF in high glucose-mediated injuries of human retinal endothelial cells in culture

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Wanzhen Jiao ◽  
Jia-Fu Ji ◽  
Wenwen Xu ◽  
Wenjuan Bu ◽  
Yuanjie Zheng ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Death ◽  
Growth Factor ◽  
High Glucose ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Blood Retinal Barrier ◽  
Western Blots ◽  
Retinal Endothelial Cells ◽  
Protein Levels

Abstract Vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) plays a crucial role in breakdown of the blood-retinal barrier due to hyperpermeability in diabetic retinopathy (DR). However, the distinct signaling driven by VEGF and PlGF in the pathogenesis of DR remains unclear. In this study, we investigated VEGF- and PlGF- related signaling pathways and their roles in cultured human microvascular retinal endothelial cells (hRECs) under high glucose conditions (HG; 25 mM). Apoptotic cell death was evaluated, and FITC conjugated bovine serum albumin across monolayer hRECs served as an index of permeability. Western blots were used to assess the protein levels of VEGF and PlGF, as well as the phosphorylation of p38MAPK, STAT1 and Erk1/2. Knockdown of VEGF and PlGF was performed by using siRNA. Following HG treatment, increases of VEGF and PlGF as well as PKC activity were detected in hRECs. Increased phosphorylations of p38MAPKThr180/Thr182, STAT1Ser727, and Erk1/2Tyr202/Tyr185 as well as VEGFR1Tyr1213 and VEGFR2Tyr1175 were also detected in HG-treated hRECs. Inhibition of PKC activity by Go 6976 prevented HG-induced increases of phosphor-Erk1/2 and nitric oxide synthase (NOS1) expressions as well as hyperpermeability, whereas inhibition of p38MAPK pathway by SB203580 selectively suppressed activation of STAT1 and decreased apoptotic cell death under HG conditions. Moreover, VEGF knockdown predominantly inhibited activation of VEGFR2, and phosphorylation of p38MAPK and STAT1, as well as apoptotic cell death in HG-treated hRECs. Nevertheless, PlGF knockdown mainly suppressed phosphorylation of VEGFR1, PKC, and Erk1/2, as well as NOS1 expressions and hyperpermeability. Taken together, we provide evidence demonstrating that HG-induced elevation of PlGF is responsible for hyperpermeability mainly through increasing activation of PKC-Erk1/2-NOS axis via VEGFR1, while HG-induced elevation of VEGF is associated with induction of apoptotic cell death mainly through increasing activation of p38MAPK/STAT1 signaling via VEGFR2.

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