Search results for "Tetradecanoylphorbol Acetate"
showing 10 items of 104 documents
In vivo activity of pseudoguaianolide sesquiterpene lactones in acute and chronic inflammation.
2000
The pseudoguaianolide sesquiterpene lactones 4-alpha-O-acetyl-pseudoguaian-6beta-olide (1), hymenin (2), ambrosanolide (3), tetraneurin A (4), parthenin (5), hysterin (6) and confertdiolide (7) were evaluated for their ability to affect the inflammation responses induced by different agents. All the compounds showed activity against the 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced mouse ear edema. The ethyl phenylpropiolate (EPP)-induced mouse ear edema was inhibited by compounds 3, 5 and 7. However, when sesquiterpene-lactones were assayed on the arachidonic acid (AA)-induced mouse ear edema, none of them were active. The only sesquiterpene lactone orally active against the paw mouse…
Clusterin gene expression in apoptotic MDCK cells is dependent on the apoptosis-inducing stimulus
1995
Abstract Clusterin (Apolipoprotein J, complement lysis inhibitor) is a widely expressed multifunctional glycoprotein. The expression of clusterin mRNA has been reported to be elevated in a broad spectrum of apoptotic or degenerative tissues. More recently, it was shown that within these tissues clusterin is expressed in the surviving rather than in the dying cells, and that clusterin gene expression is actually down-regulated in the apoptotic cells. We have studied the expression of the clusterin gene in apoptotic MDCK cells. Cell death was initiated by three different stimuli: application of the steroid hormone antagonist RU 486, activation of protein kinase C by the application of the pho…
Pore-forming toxins trigger shedding of receptors for interleukin 6 and lipopolysaccharide.
1996
Cleavage of membrane-associated proteins with the release of biologically active macromolecules is an emerging theme in biology. However, little is known about the nature and regulation of the involved proteases or about the physiological inducers of the shedding process. We here report that rapid and massive shedding of the interleukin 6 receptor (IL-6R) and the lipopolysaccharide receptor (CD14) occurs from primary and transfected cells attacked by two prototypes of pore-forming bacterial toxins, streptolysin O and Escherichia coli hemolysin. Shedding is not induced by an streptolysin O toxin mutant which retains cell binding capacity but lacks pore-forming activity. The toxin-dependent c…
Diverse cell surface protein ectodomains are shed by a system sensitive to metalloprotease inhibitors.
1996
The extracellular domains of a diverse group of membrane proteins are shed in response to protein kinase C activators such as phorbol 12-myristate 13-acetate (PMA). The lack of sequence similarity in the cleavage sites suggests the involvement of many proteases of diverse specificity in this process. However, a mutant Chinese hamster ovary cell line recently isolated for being defective in PMA-activated shedding of the membrane-anchored growth factor transforming growth factor alpha precursor (proTGF-alpha) is concomitantly defective in the shedding of many other unrelated membrane proteins. Here we show that independent mutagenesis and selection experiments yield shedding mutants having th…
Identification of proteins cleaved downstream of caspase activation in monocytes undergoing macrophage differentiation.
2006
We have shown previously that caspases were specifically involved in the differentiation of peripheral blood monocytes into macrophages while not required for monocyte differentiation into dendritic cells. To identify caspase targets in monocytes undergoing macrophagic differentiation, we used the human monocytic leukemic cell line U937, whose macrophagic differentiation induced by exposure to 12-O-tetradecanoylphorbol 13-acetate (TPA) can be prevented by expression of the baculovirus caspase-inhibitory protein p35. A comparative two-dimensional gel proteomic analysis of empty vector- and p35-transfected cells after 12 h of exposure to 20 nm TPA, followed by mass spectrometry analysis, iden…
Proteomic differentiation pattern in the U937 cell line
2011
The U937 cell line, originally established from a histiocytic lymphoma, has been widely used as a powerful in vitro model for haematological studies. These cells retain the immature cell phenotype and can be induced to differentiate by several factors, among which 12-O-tetradecanoyl-13-phorbol acetate (TPA). Fully differentiated cells acquire the adherent phenotype and exhibit various properties typical of macrophages. However, in spite of a great deal of research devoted to the U937 cellular model, the molecular basis of biological processes involved in the monocyte/macrophage differentiation remains unclear. The present study has been undertaken to contribute to this knowledge, in order t…
The ras-related small GTP-binding protein RhoB is immediate-early inducible by DNA damaging treatments.
1995
The low molecular weight GTP-binding proteins RhoA, RhoB, and RhoC are characterized as specific substrates for the ADP-ribosyltransferase C3 from Clostridium botulinum and are supposed to be involved in the organization of the microfilamental network and transformation. rhoB is known to be immediate-early inducible by growth factors and protein-tyrosine kinases. Since increasing evidence indicates overlapping of growth factor- and UV-induced signal pathways, we studied the effect of UV light and other genotoxic agents on early rhoB transcription. Within 30 min after UV irradiation of NIH3T3 cells, the amount of rhoB mRNA increased 3-4-fold. Elevated rhoB mRNA was accompanied by an increase…
Pharmacological approach to the pro- and anti-inflammatory effects of Ranunculus sceleratus L.
2003
Ranunculus sceleratus is a widespread species with unique toxicological and pharmacological activities. The present study seeks to assess this species' ability, both in vitro and in vivo, to modulate processes involved in inflammations. To this end, different extracts from the aerial parts of the plant were tested in several models of acute inflammation induced by tetradecanoylphorbol acetate (TPA), arachidonic acid (AA), and carrageenan, as well as in two models of delayed hypersensitivity induced by oxazolone and dinitrofluorobencene (DNFB). The extracts were also assayed in models of eicosanoid and elastase release by intact cells. When tested in vivo, all of the extracts showed anti-inf…
Anti-inflammatory glycoterpenoids from Scrophularia auriculata.
2000
The activity of the four glycoterpenoids: two saponins, verbascosaponin A and verbascosaponin, and two iridoids, scropolioside A and scrovalentinoside, isolated from Scrophularia auriculata ssp. pseudoauriculata, were studied in different models of acute and chronic inflammation. Both saponins significantly inhibited the mouse paw edema induced by carrageenan and ear edema induced by single and multiple doses of 12-O-tetradecanoylphorbol 13-acetate (TPA). Verbascosaponin A showed a potency twice as high as that of indomethacin in the acute TPA model. Verbascosaponin A and scropolioside A were active after a long latency period against ethyl phenylpropiolate edema, as are glucocorticoids. Wh…
Anti-inflammatory and antiallergic activity in vivo of lipophilic Isatis tinctoria extracts and tryptanthrin.
2006
The effects of a supercritical CO2 (SFE) extract, a dichloromethane (DCM) extract from Isatis tinctoria leaf and the alkaloidal constituent tryptanthrin were studied in acute and subchronic experimental models of inflammation. The SFE and DCM extracts showed anti-inflammatory activity in the carrageenan-induced acute mouse paw oedema (ED50 values of 78 mg/kg and 165 mg/kg P. O., respectively) and in the acute tetradecanoylphorbol acetate (TPA)-induced mouse ear oedema in oral (62% and 32% oedema reduction at 100 and 125 mg/kg, respectively) and topical application (37% and 33% reduction of oedema at 0.5 mg/ear). In contrast, tryptanthrin showed no significant anti-inflammatory effect. The D…