Reactive Oxygen Species as Downstream Mediators of Angiogenic Signaling by Vascular Endothelial Growth Factor Receptor-2/KDR

Colavitti, Renata; Pani, Giovambattista; Bedogni, Barbara; Anzevino, Rosanna; Borrello, Silvia; Waltenberger, Johannes; Galeotti, T.

doi:10.1074/jbc.m107711200

Cited by 343 publications

(249 citation statements)

References 37 publications

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“…Recently, it has been observed that DPI can cause apoptosis in rat heart cultured cells via induction of mitochondrial superoxide production (38) and induces in rat pulmonary aortic endothelial cells the transcription of heme oxygenase-1, a gene very sensitive not only to hypoxia but also to oxidative stress (39). Furthermore, in porcine aortic endothelial cells DPI potentiated the generation of ROS, both basally and after stimulation with vascular endothelial growth factor (29). Our results could then provide an explanation to such observations, reporting a "paradoxical" induction of oxidative stress by DPI.…”

Section: Resultsmentioning

confidence: 99%

Diphenyleneiodonium Inhibits the Cell Redox Metabolism and Induces Oxidative Stress

Riganti

Gazzano

Polimeni

et al. 2004

Journal of Biological Chemistry

179

133

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Diphenyleneiodonium (DPI) and the structurally related compound diphenyliodonium (DIP) are widely used as inhibitors of flavoenzymes, particularly NADPH oxidase. Here we report further evidence that DPI and DIP are not specific flavin binders. A 3-h incubation of N11 glial cells with DPI significantly inhibited in a dosedependent way both the pentose phosphate pathway and the tricarboxylic acid cycle. In parallel, we observed a dose-dependent increase of reactive oxygen species generation and lipoperoxidation and increased leakage of lactate dehydrogenase activity in the extracellular medium. The glutathione/glutathione disulfide ratio decreased, whereas the efflux of glutathione out of the cells increased. This suggests that DPI causes an augmented oxidative stress and exerts a cytotoxic effect in N11 cells. Indeed, the cells were protected from these events when loaded with glutathione. Similar results were observed using DIP instead of DPI and also in other cell types. We suggest that the DPI-elicited inhibition of the pentose phosphate pathway and tricarboxylic acid cycle may be mediated by the blockade of several NAD(P)-dependent enzymes, such as glucose 6-phosphate dehydrogenase, glyceraldehyde 3-phosphate dehydrogenase, and lactate dehydrogenase. In light of these results, we think that some effects of DPI or DIP in in vitro and in vivo experimental models should be interpreted with caution. Diphenyleneiodonium (DPI) 1 and the structurally related compound diphenyliodonium (DIP) are widely used as uncompetitive inhibitors of flavoenzymes. Firstly identified as a hypoglycemic agent able to block gluconeogenesis and respiration in rat liver (1), DPI has been subsequently shown to inhibit the activity of NADH:ubiquinone oxidoreductase (2, 3), NADPH oxidase (4 -6), nitric-oxide synthase (7), xanthine oxidase (6), and NADPH cytochrome P450 oxidoreductase (8). DPI and other iodonium derivatives have been shown to react via a radical mechanism, whereby an electron is abstracted from FAD or FMN to form a radical, which then adds back to the flavin to form covalent, phenylated adducts (9). Also, heme groups, such as the heme b of NADPH oxidase, have been found to react with DPI and DIP (10).In most experimental works of the last years, DPI or DIP have been used as inhibitors of NADPH oxidase. NADPH oxidases are a group of plasma membrane-associated enzymes found in a variety of cells of mesodermal origin. The most thoroughly studied is the leukocyte isoform, which catalyzes the production of superoxide (O 2 . ) by the one-electron reduction of oxygen, using NADPH as the reducing agent (11). The O 2 .generated by NADPH oxidase serves as the starting material for the production of a vast assortment of reactive oxidants used by phagocytes to kill invading microorganisms or tumor cells (11). A low activity NADPH oxidase is present in a variety of nonphagocytic cells, wherein this enzyme is a source of second messengers. It has been postulated, for instance, that the O 2 . generated by the aorta functions as a blood ...

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Section: Resultsmentioning

confidence: 99%

Diphenyleneiodonium Inhibits the Cell Redox Metabolism and Induces Oxidative Stress

Riganti

Gazzano

Polimeni

et al. 2004

Journal of Biological Chemistry

179

133

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“…The influence of ROS could occur through their contribution to HIF␣ stabilization (5, 33) and/or HIF␣-independent pathways, such as interacting with proteins involved in angiogenesis (11,49). To examine the involvement of HIF1␣ and HIF2␣ in the formation of HUVEC tubes under atmospheric conditions, we used an RNAi suppression approach.…”

Section: Ros Mediates Tubulogenesis Through Hif␣-independentmentioning

confidence: 99%

Unforeseen decreases in dissolved oxygen levels affect tube formation kinetics in collagen gels

Abaci

Truitt

Tan

et al. 2011

American Journal of Physiology-Cell Physiology

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The availability of oxygen (O2) is a critical parameter affecting vascular tube formation. In this study, we hypothesize that dissolved oxygen (DO) levels in collagen gels change during the three-dimensional (3D) culture of human umbilical vein endothelial cells (HUVECs) in atmospheric conditions and that such changes affect the kinetics of tube formation through the production of reactive oxygen species (ROS). We demonstrate a decrease in O2 tension during 3D cultures of HUVECs. Noninvasive measurements of DO levels during culture under atmospheric conditions revealed a profound decrease that reached as low as 2% O2 at the end of 24 h. After media replacement, DO levels rose rapidly and equilibrated at ϳ15% O 2, creating a reoxygenated environment. To accurately estimate DO gradients in 3D collagen gels, we developed a 3D mathematical model and determined the Michaelis-Menten parameters, V max and K m, of HUVECs in collagen gels. We detected an increase in ROS levels throughout the culture period. Using diphenyliodonium to inhibit ROS production resulted in the complete inhibition of tube formation. Interference RNA studies further showed that hypoxiainducible factors (HIFs)-1␣ and -2␣ are not involved in the formation of 3D tubes in collagen gels. We conclude that ROS affect the tubulogenesis process through HIF␣-independent pathways, where the levels of ROS are influenced by the uncontrolled variations in DO levels. This study is the first demonstration of the critical and unexpected role of O 2 during 3D in vitro culture models of tubulogenesis in atmospheric conditions. microvasculature; reactive oxygen species; hypoxia-inducible factors AN UNDERSTANDING OF THE MECHANISMS controlling how blood vessels form from endothelial cells (ECs) is crucial for developmental biology and vascular tissue engineering. In recent decades, our understanding of the molecular regulation underlying vascular development has vastly expanded, primarily because of newly available, well-defined in vitro models. One common model is the culturing of ECs in gels made of the extracellular matrix component collagen, which has enabled us to investigate the effects of many factors on tubulogenesis (24,38,39).The availability of oxygen (O 2 ) is a critical parameter affecting how vascular cells form tubes. In vitro models have demonstrated that hypoxic conditions enhance tube formation, as do hypoxic regions formed by the O 2 consumption of the cells in threedimensional (3D) structures (3,19,32). Research has shown that the rate of O 2 consumption of cells follows the Michaelis-Menten kinetics and depends on the cell type, cell density (15), and dissolved oxygen (DO) levels (1). Variations in DO levels strongly affect angiogenesis (19, 48) through different vascular cell responses, such as viability, differentiation, migration, and remodeling of the extracellular matrix (4, 27, 40).Hypoxia-inducible factors (HIFs) and reactive oxygen species (ROS) are among the effectors responsible for cellular responses to changing DO levels. HIF1␣ and HI...

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“…This is because radical formation is, in the first place, an essential component of cell metabolism, taking part in the catalysis of numerous enzymatic activities [2,11] and in the fine control of cell metabolism through the control local redox potential [11,12]. ROS can be induced, as second messenger, by cytokines, oncogenes, growth factors or hormones [11,[13][14][15][16]. ROS of external origin or resulting from some insult to the cells or from deviation of the usual metabolism of oxygen can mimic the effects of ROS induced as constitutive second messenger and can trigger activation of many transcription factors through the release of signaling proteins [11,17,18].…”

Section: Overview Of Radical Phenomenamentioning

confidence: 99%

Gestation linked radical oxygen species fluxes and vitamins and trace mineral deficiencies in the ruminant

2006

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-In mammals, radical oxygen species (ROS) are essential factors of cell replication, differentiation and growth (oxidative signal), notably during gestation, but are also potentially damaging agents. In Women, ROS play a role in remodeling of uterine tissues, implantation of the embryo, settlement of the villi and development of blood vessels characteristic of gestation. The body stores of vitamins and minerals of gestating females are used to keep ROS fluxes at a level corresponding to oxidative signals and to prevent an imbalance between their production and scavenging (oxidative stress), which would be detrimental to the mother and fetus. There is some evidence that, although based on different regulatory mechanisms, most of the effects of ROS reported in humans also occur in pregnant ruminant females, some of which have been actually reported. Many vitamins and trace elements have dual effects in the organism of mammals: (a) they are involved in the control of metabolic pathways or/and gene expression, (b) but most of the time they also display ROS trapping activity or their deficiencies induce high rates of ROS production. Deficiencies induce different disorders of gestation and can be induced by different kinds of stress. An example is given, corresponding to the decreased contents of cobalt of forages, when exposed to sustained heavy rains, so that the supply of vitamins B12 to the organism of the ruminant that grazes them is reduced and failure of gestation is induced. Outdoor exposure of ruminants to adverse climatic conditions by itself can increase the vitamin and trace element requirements. Adaptation of production systems taking into account these interactions between gestation and sources of stress or change of the quality of feeding stuffs as well as further developments of knowledge in that field is necessary to promote sustainable agricultural practices.gestation / ovine / bovine / vitamins / trace elements / antioxidant enzymes / radical oxygen species / radical phenomena

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Reactive Oxygen Species as Downstream Mediators of Angiogenic Signaling by Vascular Endothelial Growth Factor Receptor-2/KDR

Cited by 343 publications

References 37 publications

Diphenyleneiodonium Inhibits the Cell Redox Metabolism and Induces Oxidative Stress

Diphenyleneiodonium Inhibits the Cell Redox Metabolism and Induces Oxidative Stress

Unforeseen decreases in dissolved oxygen levels affect tube formation kinetics in collagen gels

Gestation linked radical oxygen species fluxes and vitamins and trace mineral deficiencies in the ruminant

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