Search results for "DASE"
showing 10 items of 1891 documents
Non-eosinophilic Airway Hyper-reactivity in Mice, Induced by IFN-γProducing CD4+and CD8+Lung T cells, is Responsive to Steroid Treatment
2014
Non-eosinophilic asthma is characterized by infiltration of neutrophils into the lung and variable responsiveness to glucocorticoids. The pathophysiological mechanisms have not been characterized in detail. Here, we present an experimental asthma model in mice associated with non-eosinophilic airway inflammation and airway hyper-responsiveness (AHR). For this, BALB/c mice were sensitized by biolistic DNA immunization with a plasmid encoding the model antigen β-galactosidase (pFascin-βGal mice). For comparison, eosinophilic airway inflammation was induced by subcutaneous injection of βGal protein (βGal mice). Intranasal challenge of mice in both groups induced AHR to a comparable extent as w…
Mechanism of Reaction of Melatonin with Human Myeloperoxidase
2001
Recently, it was suggested that melatonin (N-acetyl-5-methoxytryptamine) is oxidized by activated neutrophils in a reaction most probably involving myeloperoxidase (Biochem. Biophys. Res. Commun. (2000) 279, 657-662). Myeloperoxidase (MPO) is the most abundant protein of neutrophils and is involved in killing invading pathogens. To clarify if melatonin is a substrate of MPO, we investigated the oxidation of melatonin by its redox intermediates compounds I and II using transient-state spectral and kinetic measurements at 25 degrees C. Spectral and kinetic analysis revealed that both compound I and compound II oxidize melatonin via one-electron processes. The second-order rate constant measur…
Diterpenoids from Tetraclinis articulata that Inhibit Various Human Leukocyte Functions
2003
Ten new compounds, eight of them pimarane derivatives (1-8), together with a menthane dimer (9) and a totarane diterpenoid (10), were isolated from the leaves and wood of Tetraclinis articulata. The structures of 1-10 were established by using spectroscopic techniques, including 2D NMR spectra. Pimaranes 1-5 were found to possess an unusual cis interannular union of the B and C rings, which, from a biogenetic perspective, could be derived from the hydration of a carbocation at C-8. Compounds 4-6 and a mixture of 7 and 11 modulated different human leukocyte functions at a concentration of 10 microM, mainly the degranulation process measured as myeloperoxidase release and, to a lesser extent,…
Competitive interaction of three peroxidizing herbicides with the binding of 3H acifluorfen to corn etioplast membranes
1990
AbstractThe specific binding of the herbicide acifluorfen 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid to corn etioplast membranes is competitively inhibited by protoporphyrinogen IX, the substrate of protoporphyrinogen oxidase. Three other peroxidizing molecules, oxadiazon [5-ter-butyl-3-(2,4-dichloro-5-isopropoxyphenyl)-1,3,4-oxadiazol-2-one], LS 82556 [(S)3-N-(methylbenzyl)carbamoyl-5-propionyl-2,6-lutidine], and M&B 39279 [5-amino-4-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazol], also compete with acifluorfen for its binding site. The four herbicides thus bind to the same site, or to closely located sites, on the enzyme protoporphyrinogen oxidase.
Reciprocal regulation of endothelial nitric-oxide synthase and NADPH oxidase by betulinic acid in human endothelial cells.
2007
Nitric oxide (NO) produced by endothelial NO synthase (eNOS) is a protective principle in the vasculature. Many cardiovascular diseases are associated with reduced NO bioactivity and eNOS uncoupling due to oxidative stress. Compounds that reverse eNOS uncoupling and increase eNOS expression are of therapeutic interest. Zizyphi Spinosi semen (ZSS) is one of the most widely used traditional Chinese herbs with protective effects on the cardiovascular system. In human umbilical vein endothelial cells (HUVEC) and HUVEC-derived EA.hy 926 cells, an extract of ZSS increased eNOS promoter activity, eNOS mRNA and protein expression, and NO production in a concentration- and time-dependent manner. Maj…
Ursolic acid from the Chinese herb Danshen (Salvia miltiorrhiza L.) upregulates eNOS and downregulates Nox4 expression in human endothelial cells
2007
Danshen, the dried root of Salvia miltiorrhiza Bunge (Lamiaceae), is one of the most commonly used traditional Chinese medicines for cardiovascular indications. In EA.hy 926 cells, a cell line derived from human umbilical vein endothelial cells (HUVEC), an aqueous extract of danshen, and also a methanol extract of the plant, increased eNOS promoter activity, eNOS mRNA and protein expression, as well as endothelial NO production. A dichloromethane extract, in contrast, did not change eNOS gene expression. Thus, the active danshen constituent(s) responsible for eNOS upregulation is (are) hydrophilic and/or alcohol-soluble. One such compound is ursolic acid that significantly increased eNOS ex…
Role of oxidative and nitrosative stress biomarkers in chronic heart failure
2009
In this review, we present recent insights on chronic heart failure (CHF) and the potential role of tumor necrosis factor (TNF)-alpha, interleukins, myeloperoxidase (MPO), and nitrosative stress in the progression of this disease process. Reactive oxygen species (ROS) are produced as a consequence of aerobic metabolism. Under physiologic conditions, their unfavourable effect in causing oxidative damage is counteracted by antioxidants. An imbalance in favour of oxidants leads to oxidative stress, and contributes to myocyte apoptosis, direct negative inotropic effects, and reduced bioavailability of nitric oxide (NO). Together, these effects lead to impaired vasodilatation of the coronary, pu…
Protective Effect of Sildenafil against Estradiol-induced ROS production
2010
Several reports suggest that xanthine dehydrogenase (XDH) and its oxidase form (XO) play an important role in various forms of ischemic and vascular injuries. Recently we have demonstrated that 17β-estradiol (E2) induces a significant decrease of the expression and activity of XDH and its conversion to XO in human mammary epithelial cells. E2 is known to induce upregulation of eNOS gene expression in aortic endothelial cells. In light of the ability of XO-derived O2•¯ to combine with •NO to yield ONOO¯, and considering that ONOO¯ converts XDH to XO, it is important to protect tissues against the XO increased activity and ROS increased production, that would in turn react with •NO to augment…
Afferent and efferent connections of the olfactory bulbs in the lizard Podarcis hispanica.
1991
The connections of the olfactory bulbs of Podarcis hispanica were studied by tract-tracing of injected horseradish peroxidase. Restricted injections into the main olfactory bulb (MOB) resulted in bilateral terminallike labeling in the medial part of the anterior olfactory nucleus (AON) and in the rostral septum, lateral cortex, nucleus of the lateral olfactory tract, and ventrolateral amygdaloid nucleus. Bilateral retrograde labeling was found in the rostral lateral cortex and in the medial and dorsolateral AON. Ipsilaterally the dorsal cortex, nucleus of the diagonal band, lateral preoptic area, and dorsolateral amygdala showed labeled cell bodies. Retrogradely labeled cells were also foun…
Microvesicles shed by oligodendroglioma cells and rheumatoid synovial fibroblasts contain aggrecanase activity
2012
Membrane microvesicle shedding is an active process and occurs in viable cells with no signs of apoptosis or necrosis. We report here that microvesicles shed by oligodendroglioma cells contain an ‘aggrecanase’ activity, cleaving aggrecan at sites previously identified as targets for adamalysin metalloproteinases with disintegrin and thrombospondin domains (ADAMTSs). Degradation was inhibited by EDTA, the metalloproteinase inhibitor GM6001 and by tissue inhibitor of metalloproteinases (TIMP)-3, but not by TIMP-1 or TIMP-2. This inhibitor profile indicates that the shed microvesicles contain aggrecanolytic ADAMTS(s) or related TIMP-3-sensitive metalloproteinase(s). The oligodendroglioma cells…