Increased JNK Phosphorylation and Oxidative Stress in Response to Increased Glucose Flux through Increased GLUT1 Expression in Rat Retinal Endothelial Cells

2005 ◽  
Vol 46 (9) ◽  
pp. 3403 ◽  
Author(s):  
Jie Zhou ◽  
Baljit K. Deo ◽  
Kenichi Hosoya ◽  
Tetsuya Terasaki ◽  
Irina G. Obrosova ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Retinal Endothelial Cells ◽  
Glucose Flux ◽  
Glut1 Expression ◽  
And Oxidative Stress

scholarly journals Dose Response of Bumetanide on Aquaporins and Angiogenesis Biomarkers in Human Retinal Endothelial Cells Exposed to Intermittent Hypoxia

2021 ◽  
Vol 14 (10) ◽  
pp. 967
Author(s):  
Sibel Guzel ◽  
Charles L. Cai ◽  
Jacob V. Aranda ◽  
Kay D. Beharry
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Intermittent Hypoxia ◽  
Culture Media ◽  
Tube Formation ◽  
High Dose ◽  
Oxidative Stress Biomarkers ◽  
Vascular Permeability Factor ◽  
Retinal Endothelial Cells ◽  
And Oxidative Stress

Aquaporins (AQPs) are important for regulating cellular water, solute transport, and balance. Recently, AQPs have also been recognized as playing a key role in cell migration and angiogenesis. In the retina, hypoxia induces vascular endothelial growth factor (VEGF), a potent angiogenic and vascular permeability factor, resulting in retinal edema, which is facilitated by AQPs. Bumetanide is a diuretic agent and AQP 1–4 blocker. We tested the hypothesis that bumetanide suppression of AQPs ameliorates intermittent hypoxia (IH)-induced angiogenesis and oxidative stress in human microvascular retinal endothelial cells (HMRECs). HMRECs were treated with a low-dose (0.05 µg/mL) or high-dose (0.2 µg/mL) of bumetanide and were exposed to normoxia (Nx), hyperoxia (50% O2), or IH (50% O2 with brief hypoxia 5% O2) for 24, 48, and 72 h. Angiogenesis and oxidative stress biomarkers were determined in the culture media, and the cells were assessed for tube formation capacity and AQP-1 and -4 expression. Both doses of bumetanide significantly decreased oxidative stress and angiogenesis biomarkers. This response was reflected by reductions in tube formation capacity and AQP expression. These findings confirm the role of AQPs in retinal angiogenesis. Therapeutic targeting of AQPs with bumetanide may be advantageous for IH-induced aberrant retinal development.

scholarly journals Lysophosphatidylcholine Offsets the Protective Effects of Bone Marrow Mesenchymal Stem Cells on Inflammatory Response and Oxidative Stress Injury of Retinal Endothelial Cells via TLR4/NF-κB Signaling

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Haijun Zhao ◽  
Yanhui He
Keyword(s):  
Oxidative Stress ◽  
Stem Cells ◽  
Bone Marrow ◽  
Endothelial Cells ◽  
Inflammatory Response ◽  
Protective Effects ◽  
Stress Injury ◽  
Oxidative Stress Injury ◽  
Marrow Mesenchymal Stem Cells ◽  
And Oxidative Stress

Diabetic retinopathy (DR), as a major cause of blindness worldwide, is one common complication of diabetes mellitus. Inflammatory response and oxidative stress injury of endothelial cells play significant roles in the pathogenesis of DR. The study is aimed at investigating the effects of lysophosphatidylcholine (LPC) on the dysfunction of high glucose- (HG-) treated human retinal microvascular endothelial cells (HRMECs) after being cocultured with bone marrow mesenchymal stem cells (BMSCs) and the underlying regulatory mechanism. Coculture of BMSCs and HRMECs was performed in transwell chambers. The activities of antioxidant-related enzymes and molecules of oxidative stress injury and the contents of inflammatory cytokines were measured by ELISA. Flow cytometry analyzed the apoptosis of treated HRMECs. HRMECs were further treated with 10-50 μg/ml LPC to investigate the effect of LPC on the dysfunction of HRMECs. Western blotting was conducted to evaluate levels of TLR4 and p-NF-κB proteins. We found that BMSCs alleviated HG-induced inflammatory response and oxidative stress injury of HRMECs. Importantly, LPC offsets the protective effects of BMSCs on inflammatory response and oxidative stress injury of HRMECs. Furthermore, LPC upregulated the protein levels of TLR4 and p-NF-κB, activating the TLR4/NF-κB signaling pathway. Overall, our study demonstrated that LPC offsets the protective effects of BMSCs on inflammatory response and oxidative stress injury of HRMECs via TLR4/NF-κB signaling.

scholarly journals New Perspectives of S-Adenosylmethionine (SAMe) Applications to Attenuate Fatty Acid-Induced Steatosis and Oxidative Stress in Hepatic and Endothelial Cells

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4237 ◽  
Author(s):  
Laura Vergani ◽  
Francesca Baldini ◽  
Mohamad Khalil ◽  
Adriana Voci ◽  
Pietro Putignano ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Fatty Acid ◽  
Lipid Accumulation ◽  
Endothelium Dysfunction ◽  
Beneficial Effects ◽  
Mitochondrial Fatty Acid ◽  
Oxidant Production ◽  
Pleiotropic Functions ◽  
And Oxidative Stress

S-adenosylmethionine (SAMe) is an endogenous methyl donor derived from ATP and methionine that has pleiotropic functions. Most SAMe is synthetized and consumed in the liver, where it acts as the main methylating agent and in protection against the free radical toxicity. Previous studies have shown that the administration of SAMe as a supernutrient exerted many beneficial effects in various tissues, mainly in the liver. In the present study, we aimed to clarify the direct effects of SAMe on fatty acid-induced steatosis and oxidative stress in hepatic and endothelial cells. Hepatoma FaO cells and endothelial HECV cells exposed to a mixture of oleate/palmitate are reliable models for hepatic steatosis and endothelium dysfunction, respectively. Our findings indicate that SAMe was able to significantly ameliorate lipid accumulation and oxidative stress in hepatic cells, mainly through promoting mitochondrial fatty acid entry for β-oxidation and external triglyceride release. SAMe also reverted both lipid accumulation and oxidant production (i.e., ROS and NO) in endothelial cells. In conclusion, these outcomes suggest promising beneficial applications of SAMe as a nutraceutical for metabolic disorders occurring in fatty liver and endothelium dysfunction.

scholarly journals Emerging Roles of Redox-Mediated Angiogenesis and Oxidative Stress in Dermatoses

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Dehai Xian ◽  
Jing Song ◽  
Lingyu Yang ◽  
Xia Xiong ◽  
Rui Lai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Growth Factors ◽  
Molecular Mechanisms ◽  
Capillary Tube ◽  
Proteolytic Enzymes ◽  
Skin Tumor ◽  
Antioxidant Systems ◽  
Antiangiogenic Factors ◽  
And Oxidative Stress

Angiogenesis is the process of new vessel formation, which sprouts from preexisting vessels. This process is highly complex and primarily involves several key steps, including stimulation of endothelial cells by growth factors, degradation of the extracellular matrix by proteolytic enzymes, migration and proliferation of endothelial cells, and capillary tube formation. Currently, it is considered that multiple cytokines play a vital role in this process, which consist of proangiogenic factors (e.g., vascular endothelial growth factor, fibroblast growth factors, and angiopoietins) and antiangiogenic factors (e.g., endostatin, thrombospondin, and angiostatin). Angiogenesis is essential for most physiological events, such as body growth and development, tissue repair, and wound healing. However, uncontrolled neovascularization may contribute to angiogenic disorders. In physiological conditions, the above promoters and inhibitors function in a coordinated way to induce and sustain angiogenesis within a limited period of time. Conversely, the imbalance between proangiogenic and antiangiogenic factors could cause pathological angiogenesis and trigger several diseases. With insights into the molecular mechanisms of angiogenesis, increasing reports have shown that a close relationship exists between angiogenesis and oxidative stress (OS) in both physiological and pathological conditions. OS, an imbalance between prooxidant and antioxidant systems, is a cause and consequence of many vascular complains and serves as one of the biomarkers for these diseases. Furthermore, emerging evidence supports that OS and angiogenesis play vital roles in many dermatoses, such as psoriasis, atopic dermatitis, and skin tumor. This review summarizes recent findings on the role of OS as a trigger of angiogenesis in skin disorders, highlights newly identified mechanisms, and introduces the antiangiogenic and antioxidant therapeutic strategies.

scholarly journals Rice‐derived peptide AAGALPS inhibits TNF‐α‐induced inflammation and oxidative stress in vascular endothelial cells

2019 ◽  
Vol 8 (1) ◽  
pp. 659-667 ◽  
Author(s):  
Li‐Tao Tong ◽  
Zhiyuan Ju ◽  
Liya Liu ◽  
Lili Wang ◽  
Xianrong Zhou ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Vascular Endothelial ◽  
Tnf Α ◽  
And Oxidative Stress

scholarly journals CYP1B1 expression promotes the proangiogenic phenotype of endothelium through decreased intracellular oxidative stress and thrombospondin-2 expression

Blood ◽  
2009 ◽  
Vol 113 (3) ◽  
pp. 744-754 ◽  
Author(s):  
Yixin Tang ◽  
Elizabeth A. Scheef ◽  
Shoujian Wang ◽  
Christine M. Sorenson ◽  
Craig B. Marcus ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Endothelial Cells ◽  
Retinopathy Of Prematurity ◽  
Cellular Responses ◽  
Retinal Endothelial Cells ◽  
Capillary Morphogenesis ◽  
Ischemic Retinopathy ◽  
Intracellular Oxidative Stress

Abstract Reactive species derived from cell oxygenation processes play an important role in vascular homeostasis and the pathogenesis of many diseases including retinopathy of prematurity. We show that CYP1B1-deficient (CYP1B1−/−) mice fail to elicit a neovascular response during oxygen-induced ischemic retinopathy. In addition, the retinal endothelial cells (ECs) prepared from CYP1B1−/− mice are less adherent, less migratory, and fail to undergo capillary morphogenesis. These aberrant cellular responses were completely reversed when oxygen levels were lowered or an antioxidant added. CYP1B1−/− ECs exhibited increased oxidative stress and expressed increased amounts of the antiangiogenic factor thrombospondin-2 (TSP2). Increased lipid peroxidation and TSP2 were both observed in retinas from CYP1B1−/− mice and were reversed by administration of an antioxidant. Reexpression of CYP1B1 in CYP1B1−/− ECs resulted in down-regulation of TSP2 expression and restoration of capillary morphogenesis. A TSP2 knockdown in CYP1B1−/− ECs also restored capillary morphogenesis. Thus, CYP1B1 metabolizes cell products that modulate intracellular oxidative stress, which enhances production of TSP2, an inhibitor of EC migration and capillary morphogenesis. Evidence is presented that similar changes occur in retinal endothelium in vivo to limit neovascularization.

Reactive oxygen species downregulate glucose transport system in retinal endothelial cells

2011 ◽  
Vol 300 (4) ◽  
pp. C927-C936 ◽  
Author(s):  
Rosa Fernandes ◽  
Ken-ichi Hosoya ◽  
Paulo Pereira
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Plasma Membrane ◽  
Endothelial Cell ◽  
Glucose Transport ◽  
Glucose Transporter ◽  
Cell Damage ◽  
Proteasome Inhibition ◽  
Glucose Transporter 1 ◽  
Retinal Endothelial Cells

Retinal endothelial cells are believed to play an important role in the pathogenesis of diabetic retinopathy. In previous studies, we and others demonstrated that glucose transporter 1 (GLUT1) is downregulated in response to hyperglycemia. Increased oxidative stress is likely to be the event whereby hyperglycemia is transduced into endothelial cell damage. However, the effects of sustained oxidative stress on GLUT1 regulation are not clearly established. The objective of this study is to evaluate the effect of increased oxidative stress on glucose transport and on GLUT1 subcellular distribution in a retinal endothelial cell line and to elucidate the signaling pathways associated with such regulation. Conditionally immortalized rat retinal endothelial cells (TR-iBRB) were incubated with glucose oxidase, which increases the intracellular hydrogen peroxide levels, and GLUT1 regulation was investigated. The data showed that oxidative stress did not alter the total levels of GLUT1 protein, although the levels of mRNA were decreased, and there was a subcellular redistribution of GLUT1, decreasing its content at the plasma membrane. Consistently, the half-life of the protein at the plasma membrane markedly decreased under oxidative stress. The proteasome appears to be involved in GLUT1 regulation in response to oxidative stress, as revealed by an increase in stabilization of the protein present at the plasma membrane and normalization of glucose transport following proteasome inhibition. Indeed, levels of ubiquitinated GLUT1 increase as revealed by immunoprecipitation assays. Furthermore, data indicate that protein kinase B activation is involved in the stabilization of GLUT1 at the plasma membrane. Thus subcellular redistribution of GLUT1 under conditions of oxidative stress is likely to contribute to the disruption of glucose homeostasis in diabetes.

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