scholarly journals Effects of High Glucose-Induced Cx43 Downregulation on Occludin and ZO-1 Expression and Tight Junction Barrier Function in Retinal Endothelial Cells

2013 ◽  
Vol 54 (10) ◽  
pp. 6518 ◽  
Author(s):  
Thomas Tien ◽  
Kevin F. Barrette ◽  
Argyrios Chronopoulos ◽  
Sayon Roy
Keyword(s):  
Endothelial Cells ◽  
Tight Junction ◽  
High Glucose ◽  
Barrier Function ◽  
Retinal Endothelial Cells

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 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

Modulation of tight junction structure in blood-brain barrier endothelial cells. Effects of tissue culture, second messengers and cocultured astrocytes

1994 ◽  
Vol 107 (5) ◽  
pp. 1347-1357 ◽  
Author(s):  
H. Wolburg ◽  
J. Neuhaus ◽  
U. Kniesel ◽  
B. Krauss ◽  
E.M. Schmid ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tight Junction ◽  
Tight Junctions ◽  
Blood Brain Barrier ◽  
Barrier Function ◽  
Primary Cultures ◽  
Brain Barrier ◽  
Brain Endothelial Cells ◽  
Blood Brain ◽  
Camp Levels

Tight junctions between endothelial cells of brain capillaries are the most important structural elements of the blood-brain barrier. Cultured brain endothelial cells are known to loose tight junction-dependent blood-brain barrier characteristics such as macromolecular impermeability and high electrical resistance. We have directly analyzed the structure and function of tight junctions in primary cultures of bovine brain endothelial cells using quantitative freeze-fracture electron microscopy, and ion and inulin permeability. The complexity of tight junctions, defined as the number of branch points per unit length of tight junctional strands, decreased 5 hours after culture but thereafter remained almost constant. In contrast, the association of tight junction particles with the cytoplasmic leaflet of the endothelial membrane bilayer (P-face) decreased continuously with a major drop between 16 hours and 24 hours. The complexity of tight junctions could be increased by elevation of intracellular cAMP levels while phorbol esters had the opposite effect. On the other hand, the P-face association of tight junction particles was enhanced by elevation of cAMP levels and by coculture of endothelial cells with astrocytes or exposure to astrocyte-conditioned medium. The latter effect on P-face association was induced by astrocytes but not fibroblasts. Elevation of cAMP levels together with astrocyte-conditioned medium synergistically increased transendothelial electrical resistance and decreased inulin permeability of primary cultures, thus confirming the effects on tight junction structure and barrier function. P-face association of tight junction particles in brain endothelial cells may therefore be a critical feature of blood-brain barrier function that can be specifically modulated by astrocytes and cAMP levels. Our results suggest an important functional role for the cytoplasmic anchorage of tight junction particles for brain endothelial barrier function in particular and probably paracellular permeability in general.

scholarly journals Orai-IGFBP3 signaling complex regulates high-glucose exposure-induced increased proliferation, permeability, and migration of human coronary artery endothelial cells

2020 ◽  
Vol 8 (1) ◽  
pp. e001400
Author(s):  
Suwen Bai ◽  
Yuan Wei ◽  
Wenxuan Hou ◽  
YanHeng Yao ◽  
Junwei Zhu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Coronary Artery ◽  
Protein Expression ◽  
High Glucose ◽  
Barrier Function ◽  
Coronary Atherosclerosis ◽  
Human Coronary Artery ◽  
Expression Levels ◽  
Signaling Complex ◽  
Junction Protein

IntroductionDiabetes-associated endothelium dysfunction might be linked to disturbances in Ca2+ homeostasis. Our main objective is to reveal the potential mechanisms by which high-glucose (HG) exposure promotes increased proliferation of human coronary artery endothelial cells (HCAECs) in culture, and that store-operated Ca2+ entry (SOCE) and insulin-like growth factor binding protein 3 (IGFBP3) contribute to this proliferation.Research design and methodsWe detected the expression levels of Ca2+ release-activated calcium channel proteins (Orais), IGFBP3 and proliferating cell nuclear antigen of HCAECs cultured in HG medium for 1, 3, 7, and 14 days and in streptozotocin-induced diabetic mouse coronary endothelial cells. Coimmunoprecipitation and immunofluorescence technologies were used to detect the interactions between Orais and IGFBP3 of HCAECs exposed to HG environment, and to detect IGFBP3 expression and proliferation after treatment of HCAECs cultured in HG medium with an agonist or inhibitor of SOCE. Similarly, after transfection of specific small interfering RNA to knock down IGFBP3 protein expression, SOCE activity and Orais expression were tested. Some processes related to endothelial dysfunction, such as migration, barrier function and adhesion marker expression, are also measured.ResultsHG exposure promoted increased proliferation of HCAECs in culture and that SOCE and IGFBP3 contributed to this proliferation. In addition, we also found that Orais and IGFBP3 were physically associated and regulated each other’s expression levels. Besides, their expression levels and interactions were enhanced in HCAECs after exposure to HG. HG exposure promotes cell migration, but reduces barrier function and adherens junction protein expression levels in HCAECs.ConclusionOrais and IGFBP3 formed a signaling complex that mediated HCAEC proliferation during HG exposure in culture. Meanwhile, we also found that SOCE stimulates proliferation of HCAECs by regulating IGFBP3, thereby promoting the occurrence and progression of coronary atherosclerosis in diabetes. It is worth noting that our findings may shed new light on the mechanisms of increased proliferation in HCAECs in diabetes and suggest the potential value of SOCE and IGFBP3 as therapeutic targets for coronary atherosclerosis in individuals with diabetes.

scholarly journals Decursin Inhibits VEGF-Mediated Inner Blood—Retinal Barrier Breakdown by Suppression of VEGFR-2 Activation

2009 ◽  
Vol 29 (9) ◽  
pp. 1559-1567 ◽  
Author(s):  
Jin Hyoung Kim ◽  
Jeong Hun Kim ◽  
You Mie Lee ◽  
Eun-Mi Ahn ◽  
Kyu-Won Kim ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tight Junction ◽  
Vision Loss ◽  
Retinal Vessels ◽  
Tight Junction Proteins ◽  
Blood Retinal Barrier ◽  
Retinal Endothelial Cells ◽  
Extracellular Signal ◽  
Brb Breakdown ◽  
Junction Proteins

The blood—retinal barrier (BRB) is essential for the normal structural and functional integrity of the retina, whose breakdown could cause the serious vision loss. Vascular endothelial growth factor (VEGF), as a permeable factor, induces alteration of tight junction proteins to result in BRB breakdown. Herein, we demonstrated that decursin inhibits VEGF-mediated inner BRB breakdown through suppression of VEGFR-2 signaling pathway. In retinal endothelial cells, decursin inhibited VEGF-mediated hyperpermeability. Decursin prevented VEGF-mediated loss of tight junction proteins including zonula occludens-1 (ZO-1), ZO-2, and occludin in retinal endothelial cells, which was also supported by restoration of tight junction proteins in intercellular junction. In addition, decursin significantly inhibited VEGF-mediated vascular leakage from retinal vessels, which was accompanied by prevention of loss of tight junction proteins in retinal vessels. Decursin significantly suppressed VEGF-induced VEGFR-2 phosphrylation that consequently led to inhibition of extracellular signal-regulated kinase (ERK) 1/2 activation. Moreover, decursin induced no cytotoxicity to retinal endothelial cells and no retinal toxicity under therapeutic concentrations. Therefore, our results suggest that decursin prevents VEGF-mediated BRB breakdown through blocking of loss of tight junction proteins, which might be regulated by suppression of VEGFR-2 activation. As a novel inhibitor to BRB breakdown, decursin could be applied to variable retinopathies with BRB breakdown.

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