Pulmonary reduction of an intravascular redox polymer

Pulmonary endothelial cells in culture reduce external electron acceptors via transplasma membrane electron transport (TPMET). In studying endothelial TPMET in intact lungs, it is difficult to exclude intracellular reduction and reducing agents released by the lung. Therefore, we evaluated the role of endothelial TPMET in the reduction of a cell-impermeant redox polymer, toluidine blue O polyacrylamide (TBOP+), in intact rat lungs. When added to the perfusate recirculating through the lungs, the venous effluent TBOP+concentration decreased to an equilibrium level reflecting TBOP+ reduction and autooxidation of its reduced (TBOPH) form. Adding superoxide dismutase (SOD) to the perfusate increased the equilibrium TBOP+ concentration. Kinetic analysis indicated that the SOD effect could be attributed to elimination of the superoxide product of TBOPH autooxidation rather than of superoxide released by the lungs, and experiments with lung-conditioned perfusate excluded release of other TBOP+ reductants in sufficient quantities to cause significant TBOP+ reduction. Thus the results indicate that TBOP+ reduction is via TPMET and support the utility of TBOP+ and the kinetic model for investigating TPMET mechanisms and their adaptations to physiological and pathophysiological stresses in the intact lung.

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The recombinant lectin-like domain of thrombomodulin inhibits angiogenesis through interaction with Lewis Y antigen

Blood ◽

10.1182/blood-2011-08-376038 ◽

2012 ◽

Vol 119 (5) ◽

pp. 1302-1313 ◽

Cited By ~ 31

Author(s):

Cheng-Hsiang Kuo ◽

Po-Ku Chen ◽

Bi-Ing Chang ◽

Meng-Chen Sung ◽

Chung-Sheng Shi ◽

...

Keyword(s):

Endothelial Cells ◽

Egf Receptor ◽

Tube Formation ◽

Endothelial Tube Formation ◽

A Cell ◽

Lewis Y ◽

Tm Domain

AbstractLewis Y Ag (LeY) is a cell-surface tetrasaccharide that participates in angiogenesis. Recently, we demonstrated that LeY is a specific ligand of the recombinant lectin-like domain of thrombomodulin (TM). However, the biologic function of interaction between LeY and TM in endothelial cells has never been investigated. Therefore, the role of LeY in tube formation and the role of the recombinant lectin-like domain of TM—TM domain 1 (rTMD1)—in antiangiogenesis were investigated. The recombinant TM ectodomain exhibited lower angiogenic activity than did the recombinant TM domains 2 and 3. rTMD1 interacted with soluble LeY and membrane-bound LeY and inhibited soluble LeY-mediated chemotaxis of endothelial cells. LeY was highly expressed on membrane ruffles and protrusions during tube formation on Matrigel. Blockade of LeY with rTMD1 or Ab against LeY inhibited endothelial tube formation in vitro. Epidermal growth factor (EGF) receptor in HUVECs was LeY modified. rTMD1 inhibited EGF receptor signaling, chemotaxis, and tube formation in vitro, and EGF-mediated angiogenesis and tumor angiogenesis in vivo. We concluded that LeY is involved in vascular endothelial tube formation and rTMD1 inhibits angiogenesis via interaction with LeY. Administration of rTMD1 or recombinant adeno-associated virus vector carrying TMD1 could be a promising antiangiogenesis strategy.

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Synthesis of 8-epi-prostaglandin F2α by human endothelial cells: role of prostaglandin H2 synthase

Biochemical Journal ◽

10.1042/bj3440747 ◽

1999 ◽

Vol 344 (3) ◽

pp. 747-754 ◽

Cited By ~ 26

Author(s):

Michael T. WATKINS ◽

George M. PATTON ◽

Hiram M. SOLER ◽

Hassan ALBADAWI ◽

Donald E. HUMPHRIES ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Endothelial Cells ◽

Umbilical Artery ◽

Prostaglandin F2α ◽

Human Endothelial Cells ◽

Microcarrier Beads ◽

A Cell ◽

Superoxide Scavenger ◽

Negative Cell Line

The experiments described in this paper were designed to determine the mechanism underlying the increase in 8-isoprostaglandin F2α (8-epi-PGF2α) production by cultured human endothelial cells during reoxygenation following hypoxia. Human umbilical artery endothelial cells were grown on microcarrier beads and exposed to sequential periods of normoxia, hypoxia, and reoxygenation. The amount of 8-epi-PGF2α in the medium was determined by ELISA. The production of 8-epi-PGF2α decreased by greater than 90% during hypoxia. Upon reoxygenation 8-epi-PGF2α production increased linearly for 90 min reaching nearly 3 times normoxic levels. When added to the medium during reoxygenation, neither superoxide dismutase nor Tiron, a cell-permeable superoxide scavenger, inhibited 8-epi-PGF2α production. However, 8-epi-PGF2α production was inhibited by catalase. The production of 8-epi-PGF2α was also inhibited by indomethacin and aspirin. Exogenous hydrogen peroxide stimulated 8-epi-PGF2α production by normoxic cells, and aspirin inhibited the hydrogen peroxide-mediated increase in 8-epi-PGF2α production. These results indicate that the reactive oxygen species responsible for 8-epi-PGF2α synthesis during reoxygenation is hydrogen peroxide and that in endothelial cells 8-epi-PGF2α synthesis is mediated by prostaglandin H2 synthase (PGHS). To verify the role of PGHS in 8-epi-PGF2α synthesis, human PGHS-1 was expressed in COS-7 cells, a PGHS negative cell line that does not synthesize 8-epi-PGF2α. In the presence of exogenous arachidonic acid the COS-7 cells expressing human PGHS-1 produced substantial amounts of PGE2 and 8-epi-PGF2α. These data indicate that human PGHS-1 can support the synthesis of 8-epi-PGF2α and that 8-epi-PGF2α synthesis by cultured human endothelial cells during reoxygenation is dependent on the activity of PGHS-1.

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Endotoxin increases superoxide dismutase in cultured bovine pulmonary endothelial cells

AJP Cell Physiology ◽

10.1152/ajpcell.1987.252.4.c436 ◽

1987 ◽

Vol 252 (4) ◽

pp. C436-C440 ◽

Cited By ~ 59

Author(s):

Y. Shiki ◽

B. O. Meyrick ◽

K. L. Brigham ◽

I. M. Burr

Keyword(s):

Endothelial Cells ◽

Superoxide Dismutase ◽

Cytochrome C ◽

Cytochrome C Oxidase ◽

Oxygen Toxicity ◽

Mitochondrial Activity ◽

Pulmonary Endothelial Cells ◽

Endotoxin Exposure ◽

Copper Zinc ◽

Cuzn Superoxide Dismutase

Manganous (Mn) and copper zinc (CuZn) superoxide dismutase (SOD) concentrations and glutathione peroxidase (GSH-Px) and catalase (CAT) activities were measured in cultured bovine pulmonary endothelial cells with and without exposure to Escherichia coli endotoxin (10(-1) micrograms/ml) over intervals of 0.5-24 h. The activities of two mitochondrial marker enzymes, fumarase and cytochrome-c oxidase, were also measured. Endotoxin exposure caused a marked increase (9-fold) in endothelial cell Mn SOD content without significant effects on GSH-Px, CAT, fumarase, or cytochrome-c oxidase activities. Endotoxin induced a slight decrease in CuZn SOD content over 24 h. This is the first report of a selective effect of endotoxin on Mn SOD in pulmonary endothelial cells. The response appears to be independent of an increase in mitochondrial activity (no change was observed in cytochrome-c oxidase or fumarase activities). These findings support the notion that endotoxin increases generation of toxic oxygen metabolites within pulmonary endothelial cells. An endotoxin-induced increase in Mn SOD could contribute to the reported protective effect of endotoxin against oxygen toxicity in these cells.

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Activation of nuclear factor-κB during doxorubicin-induced apoptosis in endothelial cells and myocytes is pro-apoptotic: the role of hydrogen peroxide

Biochemical Journal ◽

10.1042/bj20020752 ◽

2002 ◽

Vol 367 (3) ◽

pp. 729-740 ◽

Cited By ~ 165

Author(s):

Suwei WANG ◽

Srigiridhar KOTAMRAJU ◽

Eugene KONOREV ◽

Shasi KALIVENDI ◽

Joy JOSEPH ◽

...

Keyword(s):

Endothelial Cells ◽

Nuclear Translocation ◽

Nuclear Factor Κb ◽

Nuclear Factor ◽

Apoptotic Pathway ◽

Toxic Side Effect ◽

Rat Cardiomyocytes ◽

A Cell ◽

Induced Apoptosis

Doxorubicin (DOX) is a widely used anti-tumour drug. Cardiotoxicity is a major toxic side effect of DOX therapy. Although recent studies implicated an apoptotic pathway in DOX-induced cardiotoxicity, the mechanism of DOX-induced apoptosis remains unclear. In the present study, we investigated the role of reactive oxygen species and the nuclear transcription factor nuclear factor κB (NF-κB) during apoptosis induced by DOX in bovine aortic endothelial cells (BAECs) and adult rat cardiomyocytes. DOX-induced NF-κB activation is both dose- and time-dependent, as demonstrated using electrophoretic mobility-shift assay and luciferase and p65 (Rel A) nuclear-translocation assays. Addition of a cell-permeant iron metalloporphyrin significantly suppressed NF-κB activation and apoptosis induced by DOX. Overexpression of glutathione peroxidase, which detoxifies cellular H2O2, significantly decreased DOX-induced NF-κB activation and apoptosis. Inhibition of DOX-induced NF-κB activation by a cell-permeant peptide SN50 that blocks translocation of the NF-κB complex into the nucleus greatly diminished DOX-induced apoptosis. Apoptosis was inhibited when IκB mutant vector, another NF-κB inhibitor, was added to DOX-treated BAECs. These results suggest that NF-κB activation in DOX-treated endothelial cells and myocytes is pro-apoptotic, in contrast with DOX-treated cancer cells, where NF-κB activation is anti-apoptotic. Removal of intracellular H2O2 protects endothelial cells and myocytes from DOX-induced apoptosis, possibly by inhibiting NF-κB activation. These findings suggest a novel mechanism for enhancing the therapeutic efficacy of DOX.

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Light-induced oxidation-reduction reactions in a cell-free preparation from the blue-green alga Nostoc muscorum: The role of cytochrome f, cytochrome b558, C550, and P700 in noncyclic electron transport

Biochimica et Biophysica Acta (BBA) - Bioenergetics ◽

10.1016/0005-2728(73)90104-7 ◽

1973 ◽

Vol 325 (2) ◽

pp. 284-296 ◽

Cited By ~ 17

Author(s):

David B. Knaff

Keyword(s):

Electron Transport ◽

Green Alga ◽

Cytochrome F ◽

Nostoc Muscorum ◽

Blue Green Alga ◽

Reduction Reactions ◽

Cytochrome B558 ◽

Oxidation Reduction ◽

A Cell

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Receptors and ionic transporters in nuclear membranes: new targets for therapeutical pharmacological interventions

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y2012-077 ◽

2012 ◽

Vol 90 (8) ◽

pp. 953-965 ◽

Cited By ~ 18

Author(s):

Ghassan Bkaily ◽

Levon Avedanian ◽

Johny Al-Khoury ◽

Lena Ahmarani ◽

Claudine Perreault ◽

...

Keyword(s):

Endothelial Cells ◽

Nuclear Membrane ◽

Plasma Membranes ◽

Vascular Endothelial Cells ◽

Membrane Receptors ◽

Ionic Homeostasis ◽

Nuclear Membranes ◽

Ionic Transporters ◽

A Cell

Work from our group and other laboratories showed that the nucleus could be considered as a cell within a cell. This is based on growing evidence of the presence and role of nuclear membrane G-protein coupled receptors and ionic transporters in the nuclear membranes of many cell types, including vascular endothelial cells, endocardial endothelial cells, vascular smooth muscle cells, cardiomyocytes, and hepatocytes. The nuclear membrane receptors were found to modulate the functioning of ionic transporters at the nuclear level, and thus contribute to regulation of nuclear ionic homeostasis. Nuclear membranes of the mentioned types of cells possess the same ionic transporters; however, the type of receptors is cell-type dependent. Regulation of cytosolic and nuclear ionic homeostasis was found to be dependent upon a tight crosstalk between receptors and ionic transporters of the plasma membranes and those of the nuclear membrane. This crosstalk seems to be the basis for excitation–contraction coupling, excitation–secretion coupling, and excitation – gene expression coupling. Further advancement in this field will certainly shed light on the role of nuclear membrane receptors and transporters in health and disease. This will in turn enable the successful design of a new class of drugs that specifically target such highly vital nuclear receptors and ionic transporters.

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FEASIBILITY OF THE NON-CODING RNA GRADIENTS IN CELLS

Biophysical Reviews and Letters ◽

10.1142/s1793048009001034 ◽

2009 ◽

Vol 04 (03) ◽

pp. 267-272 ◽

Cited By ~ 6

Author(s):

VLADIMIR P. ZHDANOV

Keyword(s):

Kinetic Model ◽

Gene Transcription ◽

Eukaryotic Cells ◽

Model Parameters ◽

Protein Association ◽

Non Coding Rna ◽

A Cell ◽

Non Coding Rnas ◽

Spatio Temporal

In eukaryotic cells, the gene transcription often results in the formation of non-coding RNAs (ncRNAs). The key function of such RNAs is to bind to and modulate the activity of mRNAs and/or proteins. To scrutinize this ncRNA function in a cell, the author (i) proposes a spatio-temporal kinetic model, including ncRNA–protein association and degradation, (ii) derives a criterion of feasibility of the ncRNA gradients, and (iii) shows that this criterion can be satisfied with physically reasonable values of the model parameters. Thus, the ncRNA gradients are feasible. For the ncRNA–mRNA association and degradation, the situation is similar. The likely biological role of such gradients is open for debate.

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