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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tumor cells are known to produce larger amounts of reactive oxygen species (ROS) than normal cells. Although numerous reports have indicated the importance of ROS in urokinase plasminogen activator (uPA) production, the precise mechanisms remain controversial. In our study, we investigated the effect of ROS on uPA generation in human hepatoma cells, HepG2 and Hep 3B. We determined the effects of hepatocyte growth factor (HGF) on the regulation of ROS, which resulted in suppression of ROS production, as measured with the fluorescent probe, 2'-7'-dichlorofluorescein diacetate. The role of HGF in modulating ROS production, particularly that regulated by Rac-1, was determined. HGF suppressed the increment in Rac-1-regulated ROS in both cell lines. Treatment with 200 micrometer of H(2)O(2) showed a 1.6-2.1 fold increment in HGF, but a little increment occurred at 500 micrometer of H(2)O(2). It looks no dose dependent manner. Combined treatment with H(2)O(2) and HGF, resulted in a slightly increased production of HGF compared to no treatment (control). Also, H(2)O(2) upregulated uPA expression in both hepatoma cell lines. To identify the downstream pathways regulated by ROS, we treated cells with PD 98059, an MEK inhibitor, and SB 203580, a p38 inhibitor, after treatment with H(2)O(2), and showed negative control between ERK and p38 kinase activities for uPA regulation. We found that HGF modulate Rac-1-regulated ROS production through activation of Akt and ROS regulates uPA production via MAP kinase, which provides a novel clue to clarify the mechanism underlying hepatoma progression.
Exp Mol Med 2009 Mar 31
PMID:Reactive oxygen species regulate the generation of urokinase plasminogen activator in human hepatoma cells via MAPK pathways after treatment with hepatocyte growth factor. 1929 37

Oxidative burst provides the mechanism for specialized phagocytes, such as granulocytes or monocytes, to kill invading microorganisms through generation of superoxide anions. However, the oxidants generated during the burst damage DNA of the phagocytes and neighboring cells. Human blood leukocytes treated with phorbol myristate acetate (PMA) are considered to represent the experimental model of induction of oxidative burst. We recently reported that DNA damage in PMA-treated leukocytes is assessed by cytometric analysis of the induction of histone H2AX phosphorylation and Ataxia Telangiectasia Mutated (ATM) activation. In the present study we observed that hyaluronic acid (HA) of average molecular weight (MW) 5.4x10(6) and 2x10(6) at 0.1% (w/v) concentration significantly attenuated H2AX phosphorylation and ATM activation induced in leukocytes during oxidative burst. HA also reduced the intracellular level of PMA-induced reactive oxidants as measured by the ability of cells to oxidize 2',7'-dihydro-dichlorofluorescein-diacetate. No such effect was seen with HA of 6x10(4) MW. The data are consistent with earlier observations that HA of high MW protects DNA from oxidative damage induced by endo- or exogenous oxidants. The anti-oxidant effect of HA seen during oxidative burst also explains its anti-inflammatory effect when used to treat arthritic joints.
Int J Mol Med 2009 May
PMID:Attenuation of the oxidative burst-induced DNA damage in human leukocytes by hyaluronan. 1936 Mar 30

Our aim was to determine whether a Vaccinium myrtillus (bilberry) anthocyanoside (VMA) and/or its main anthocyanidin constituents (cyanidin, delphinidin, and malvidin) can protect retinal ganglion cells (RGCs) against retinal damage in vitro and in vivo. In RGC cultures (RGC-5, a rat ganglion cell-line transformed using E1A virus) in vitro, cell damage and radical activation were induced by 3-(4-morpholinyl) sydnonimine hydrochloride (SIN-1, a peroxynitrite donor). Cell viability was measured using a water-soluble tetrazolium salt assay. Intracellular radical activation within RGC-5 cells was evaluated using 5-(and-6)-chloromethyl-2,7-dichlorodihydrofluorescein diacetate acetyl ester (CM-H(2)DCFDA). Lipid peroxidation was assessed using the supernatant fraction of mouse forebrain homogenates. In mice in vivo, we evaluated the effects of VMA on N-methyl-D-aspartic acid (NMDA)-induced retinal damage using hematoxylin-eosin and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) stainings. VMA and all three anthocyanidins (i) significantly inhibited SIN-1-induced neurotoxicity and radical activation in RGC-5, (ii) concentration-dependently inhibited lipid peroxidation in mouse forebrain homogenates. Intravitreously injected VMA significantly inhibited the NMDA-induced morphological retinal damage and increase in TUNEL-positive cells in the ganglion cell layer. Thus, VMA and its anthocyanidins have neuroprotective effects (exerted at least in part via an anti-oxidation mechanism) in these in vitro and in vivo models of retinal diseases.
Mol Nutr Food Res 2009 Jul
PMID:Bilberry and its main constituents have neuroprotective effects against retinal neuronal damage in vitro and in vivo. 1941 65

Mesenchymal stromal cells (MSC) have been suggested to provide a suitable cellular environment for in vitro expansion of haematopoietic stem and progenitor cells (HPC) from umbilical cord blood. In this study, we have simultaneously analysed the cell division history and immunophenotypic differentiation of HPC by using cell division tracking with carboxyfluorescein diacetate N-succinimidyl ester (CFSE). Co-culture with MSC greatly enhanced proliferation of human HPC, especially of the more primitive CD34(+)CD38(-) fraction. Without co-culture CD34 and CD133 expressions decreased after several cell divisions, whereas CD38 expression was up-regulated after some cell divisions and then diminished in fast proliferating cells. Co-culture with MSC maintained a primitive immunophenotype (CD34(+), CD133(+) and CD38(-)) for more population doublings, whereas up-regulation of differentiation markers (CD13, CD45 and CD56) in HPC was delayed to higher numbers of cell divisions. Especially MSC of early cell passages maintained CD34 expression in HPC over more cell divisions, whereas MSC of higher passages further enhanced their proliferation rate. Inhibition of mitogen-activated protein kinase 1 (MAPK1) impaired proliferation and differentiation of HPC, but not maintenance of long-term culture initiating cells. siRNA knockdown of N-cadherin and VCAM1 in feeder layer cells increased the fraction of slow dividing HPC, whereas knockdown of integrin beta 1 (ITGB1) and CD44 impaired their differentiation. In conclusion, MSC support proliferation as well as self-renewal of HPC with primitive immunophenotype. The use of early passages of MSC and genetic manipulation of proteins involved in HPC-MSC interaction might further enhance cord blood expansion on MSC.
J Cell Mol Med 2010 Jan
PMID:Co-culture with mesenchymal stromal cells increases proliferation and maintenance of haematopoietic progenitor cells. 1943 17

Various genetic and physiological aspects of resistance of Lycopersicon spp. to Oidium neolycopersici have been reported, but limited information is available on the molecular background of the plant-pathogen interaction. This article reports the changes in nitric oxide (NO) production in three Lycopersicon spp. genotypes which show different levels of resistance to tomato powdery mildew. NO production was determined in plant leaf extracts of L. esculentum cv. Amateur (susceptible), L. chmielewskii (moderately resistant) and L. hirsutum f. glabratum (highly resistant) by the oxyhaemoglobin method during 216 h post-inoculation. A specific, two-phase increase in NO production was observed in the extracts of infected leaves of moderately and highly resistant genotypes. Moreover, transmission of a systemic response throughout the plant was observed as an increase in NO production within tissues of uninoculated leaves. The results suggest that arginine-dependent enzyme activity was probably the main source of NO in tomato tissues, which was inhibited by competitive reversible and irreversible inhibitors of animal NO synthase, but not by a plant nitrate reductase inhibitor. In resistant tomato genotypes, increased NO production was localized in infected tissues by confocal laser scanning microscopy using the fluorescent probe 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate. NO production observed in the extracts from pathogen conidia, together with elevated NO production localized in developing pathogen hyphae, demonstrates a complex role of NO in plant-pathogen interactions. Our results are discussed with regard to a possible role of increased NO production in pathogens during pathogenesis, as well as local and systemic plant defence mechanisms.
Mol Plant Pathol 2009 Jul
PMID:Local and systemic production of nitric oxide in tomato responses to powdery mildew infection. 1952 3

To explore mechanisms of nanoparticle interactions with and trafficking across lung alveolar epithelium, we utilized primary rat alveolar epithelial cell monolayers (RAECMs) and an artificial lipid bilayer on filter model (ALBF). Trafficking rates of fluorescently labeled polystyrene nanoparticles (PNPs; 20 and 100 nm, carboxylate (negatively charged) or amidine (positively charged)-modified) in the apical-to-basolateral direction under various experimental conditions were measured. Using confocal laser scanning microscopy, we investigated PNP colocalization with early endosome antigen-1, caveolin-1, clathrin heavy chain, cholera toxin B, and wheat germ agglutinin. Leakage of 5-carboxyfluorescein diacetate from RAECMs, and trafficking of (22)Na and (14)C-mannitol across ALBF, were measured in the presence and absence of PNPs. Results showed that trafficking of positively charged PNPs was 20-40 times that of negatively charged PNPs across both RAECMs and ALBF, whereas translocation of PNPs across RAECMs was 2-3 times faster than that across ALBF. Trafficking rates of PNPs across RAECMs did not change in the presence of EGTA (which decreased transepithelial electrical resistance to zero) or inhibitors of endocytosis. Confocal laser scanning microscopy revealed no intracellular colocalization of PNPs with early endosome antigen-1, caveolin-1, clathrin heavy chain, cholera toxin B, or wheat germ agglutinin. Leakage of 5-carboxyfluorescein diacetate from alveolar epithelial cells, and sodium ion and mannitol flux across ALBF, were not different in the presence or absence of PNPs. These data indicate that PNPs translocate primarily transcellularly across RAECMs, but not via known major endocytic pathways, and suggest that such translocation may take place by diffusion of PNPs through the lipid bilayer of cell plasma membranes.
Am J Respir Cell Mol Biol 2010 May
PMID:Mechanisms of alveolar epithelial translocation of a defined population of nanoparticles. 1957 31

Endogenous production of Protoporphyrin IX (PpIX) is successfully exploited for photodynamic therapy (PDT) on malignant cells, following 5-aminolevulinic acid (ALA) administration and light irradiation. This treatment kills cancer cells by damaging organelles and impairing metabolic pathways via cellular reactive oxygen species (ROS) generation. We studied the efficiency of PpIX synthetized from ALA on ROS generation, in the Vincristine resistant (LBR-V160), Doxorubicin resistant (LBR-D160) and sensitive (LBR-) murine leukemia cell lines. Cells were incubated 4 hr with 1 mM ALA and then irradiated during different times with fluorescent light. One hour later, production of ROS was analyzed by flow cytometry using different fluorescent probes: Hydroethidine (HE) for superoxide anion, 2',7' Dichlorodihydrofluorescein diacetate (DCFH-DA) for hydrogen peroxide; mitochondrial damage was examined with 3,3' Dihexyloxacarbocyanine iodide (DiOC6). We found that superoxide anion production in the three cell lines increased with irradiation time whereas no peroxide hydrogen was detected. Mitochondrial damage also increased in an irradiation time dependent manner, being higher in the Vincristine resistant line. Previous studies have demonstrated that apoptotic cell death increased with irradiation time, which is consistent with these results, indicating that ROS are critical in ALA-PDT efficiency to kill malignant cells.
Cell Mol Biol (Noisy-le-grand) 2009 Jul 01
PMID:Ros production by endogenously generated Protoporphyrin IX in murine leukemia cells. 1965 46

Intracellular mechanisms underlying the functional suppression of ionotropic glutamate receptors by activation of metabotropic glutamate receptors were investigated in cultured chick Purkinje neurons. The intracellularly recorded depolarization induced by L-AMPA (an ionotropic glutamate receptor agonist, (S)-alpha-amino-4-hydroxy-5-methyl-4-isoxazolepropionic acid) and the L-AMPA-induced inward current recorded by whole-cell voltage clamping were used. L-AMPA responses were suppressed by trans-ACPD (a selective agonist of metabotropic glutamate receptor, (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid) for various durations, with the longest duration about 60 min. This trans-ACPD effect was antagonized by l-(+)-2-amino-3-phosphonopropionic acid (a metabotropic glutamate receptor antagonist) and N(G) -monomethyl-L-arginine (a nitric oxide synthase inhibitor). Sodium nitroprusside, 3-morpholinosydnonimine (nitric oxide donors), and potassium ferricyanide mimicked trans-ACPD, and effects of trans -ACPD, sodium nitroprusside, and 3-morpholinosydnonimine were blocked by hemoglobin (a nitric oxide scavenger) but not by methemoglobin, while the effect of potassium ferricyanide was not affected by either hemoglobin or methemoglobin. 8-Bromo-cGMP also suppressed L-AMPA responses. KT5823 (a protein kinase G inhibitor) antagonized effects of trans-ACPD, 8-bromo-cGMP, and sodium nitroprusside. Phorbol 12,13-diacetate (a protein kinase C activator) also suppressed L-AMPA responses, and phorbol 12,13-diacetate plus trans-ACPD or phorhol 12,13-diacetate plus sodium nitroprusside showed an additive effect. Calphostin C and polymyxin B (protein kinase C inhibitors) antagonized the effect of trans-ACPD. These results suggest that activation of metabotropic glutamate receptors leads to the functional suppression of L-AMPA-sensitive ionotropic glutamate receptors in chick Purkinje neurons, and trans-ACPD-induced suppression of L-AMPA responses can be mimicked by activation of protein kinase G and/or protein kinase C. The involvement of nitric oxide in the trans-ACPD effect is discussed.
Mol Cell Neurosci 1993 Aug
PMID:Intracellular Mechanisms Underlying the Suppression of AMPA Responses by trans-ACPD in Cultured Chick Purkinje Neurons. 1991 44

The identification of a suitable non-fluorescent molecule that can be oxidized by G-quadruplexes into a fluorescent product will be important for several fields such as bioanalyte sensing and cancer therapeutic discovery. Herein, we demonstrate that 2',7'-dichlorodihydrofluorescein diacetate is a superior reducing substrate for the fluorometric detection of bioanalytes using peroxidase-mimicking G-quadruplex DNAzymes.
Mol Biosyst 2010 Jan
PMID:Biomolecule detection with peroxidase-mimicking DNAzymes; expanding detection modality with fluorogenic compounds. 2002 70

Here we describe methods for the in vivo study of antiviral NK cell responses using the mouse Orthopoxvirus ectromelia virus as a model, the agent of mousepox. The methods include those specific for the preparation and use of ectromelia virus such as the production of virus stocks in tissue culture and in live mice, the purification of virus stocks, the titration of virus stocks and virus loads in organs, and the infection of mice. The chapter also includes methods for the specific study of NK cell responses in infected mice such as the preparation of organs (lymph nodes, spleen, and liver) for analysis, the study of NK cell responses by flow cytometry, the adoptive transfer of NK cells, the measurement of NK cell cytolytic activity ex vivo and in vivo, and the determination of NK cell proliferation by bromodeoxyuridine loading or by dilution of carboxyfluorescein diacetate succinimidyl ester (CFSE).
Methods Mol Biol 2010
PMID:Studying NK cell responses to ectromelia virus infections in mice. 2003 57


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