Search results for " Type II"
showing 10 items of 542 documents
Effects of chronic exercise on myocardial refractoriness: a study on isolated rabbit heart
2008
Aim: To determine whether chronic physical training increases atrial and ventricular refractoriness in isolated rabbit heart. Methods: Trained rabbits were submitted to a protocol of treadmill running. The electrophysiological parameters of refractoriness investigated in an isolated heart preparation were: (1) atrial effective refractory period (AERP) and atrial functional refractory period and ventricular effective and functional refractory periods (VERP and VFRP) using the extrastimulus technique at four different pacing cycle lengths; (2) the dominant frequency (DF) of ventricular fibrillation (VF). A multi-electrode plaque containing 256 electrodes and a spectral method were used to o…
Expression of a dominant negative type II TGF-β receptor in mouse skin results in an increase in carcinoma incidence and an acceleration of carcinoma…
1998
The role of Transforming growth factor beta (TGF-beta) in carcinogenesis is complex. There are reports on both tumor inhibition and tumor promotion by TGF-beta. To elucidate the complex role of TGF-beta in epithelial carcinogenesis, we generated transgenic mice overexpressing a dominant negative type II TGF-beta receptor in the basal cell compartment and in follicular cells of the skin. Despite the reduced responsiveness of transgenic keratinocytes to TGF-beta, both proliferation and differentiation were normal in non-irritated epidermis of these transgenic mice. Thus, interruption of signaling of all three isoforms of TGF-beta in basal and follicular cells does not disturb tissue homeostas…
Processing of procollagen III by meprins: new players in extracellular matrix assembly?
2010
Meprins α and β, a subgroup of zinc metalloproteinases belonging to the astacin family, are known to cleave components of the extracellular matrix, either during physiological remodeling or in pathological situations. In this study we present a new role for meprins in matrix assembly, namely the proteolytic processing of procollagens. Both meprins α and β release the N- and C-propeptides from procollagen III, with such processing events being critical steps in collagen fibril formation. In addition, both meprins cleave procollagen III at exactly the same site as the procollagen C-proteinases, including bone morphogenetic protein-1 (BMP-1) and other members of the tolloid proteinase family. …
Transforming growth factor beta1 T29C gene polymorphism and hypertension: relationship with cardiovascular and renal damage.
2008
Distribution of T29C TGFb1 gene polymorphism was analysed in 260 hypertensive and 134 normotensive subjects. Circulating TGFb1 and procollagen type III levels, microalbuminuria, left ventricular geometry and function were evaluated in all the hypertensives subgrouped according to T29C TGFb1 gene polymorphism. Circulating TGFb1by ELISA technique, procollagen type III by a specific radioimmunoassay, microalbuminuria by radioimmunoassay, left ventricular geometry and function by echocardiography were determined. All groups were comparable for gender, age and sex. Regarding T29C TGFb1 gene polymorphism, prevalence of TC or CC genotypes was significantly (pv0.05) higher in hypertensives than nor…
[Apoptosis of human leukemic cells induced by topoisomerase I and II inhibitors].
1996
International audience; Comparison between five human leukemic lines (BV173, HL60, U937, K562, KCL22) suggest that the main determinant of their sensitivity to topoisomerase I (camptothecin) and II (VP-16) inhibitors is their ability to regulate cell cycle progression in response to specific DNA damage, then to die through apoptosis: the more the cells inhibit cell cycle progression, the less sensitive they are. The final pathway of apoptosis induction involves a cytoplasmic signal, active at neutral pH, needing magnesium, sensitive to various protease inhibitors and activated directly by staurosporine. Modulators of intracellular signaling (calcium chelators, calmodulin inhibitors, PKC mod…
Anti-inflammatory effects of annexin-1: stimulation of IL-10 release and inhibition of nitric oxide synthesis.
2003
Annexin-1 (ANX-1) is an anti-inflammatory protein induced by glucocorticoids. Like glucocorticoids, ANX-1 and derived peptides inhibit eicosanoid synthesis, block leukocyte migration and induce apoptosis of inflammatory cells. Cytokines may possess either pro-inflammatory, i.e. interleukin(IL)-1beta, tumor necrosis factor (TNF)-alpha, IL-12 or anti-inflammatory properties, i.e. IL-4, IL-10. The experiments described in the present study have been performed to answer the question whether the anti-inflammatory action of ANX-1 may be mediated, at least in part, by the release of IL-10. In macrophage (J774) cell line cultures primed with lipolysaccharide (LPS), recombinant ANX-1 stimulated IL-1…
eNOS S-nitrosylates β-actin on Cys374 and regulates PKC-θ at the immune synapse by impairing actin binding to profilin-1.
2017
The actin cytoskeleton coordinates the organization of signaling microclusters at the immune synapse (IS); however, the mechanisms involved remain poorly understood. We show here that nitric oxide (NO) generated by endothelial nitric oxide synthase (eNOS) controls the coalescence of protein kinase C-¿ (PKC-¿) at the central supramolecular activation cluster (c-SMAC) of the IS. eNOS translocated with the Golgi to the IS and partially colocalized with F-actin around the c-SMAC. This resulted in reduced actin polymerization and centripetal retrograde flow of ß-actin and PKC-¿ from the lamellipodium-like distal (d)-SMAC, promoting PKC-¿ activation. Furthermore, eNOS-derived NO S-nitrosylated ß-…
Tetracycline inhibits the nitric oxide synthase activity induced by endotoxin in cultured murine macrophages
1998
Here we investigate the effects of tetracycline base and of a semi-synthetic tetracycline derivative, doxycycline, on the induction of inducible nitric oxide synthase and, hence, on the production of nitric oxide (NO) by lipopolysaccharide in J774 macrophage cultured in vitro. The treatment of J774 line with tetracycline base (6.25-250 microM) or doxycycline (5-50 microM) dose-dependently decreased the lipopolysaccharide-stimulated (1 microg/ml) inducible NO synthase activity and, consequently, nitrite formation. For instance, the inhibition was 70% for tetracycline base at 250 microM and 68% for doxycycline at 50 microM. The inhibitory effect of tetracyclines was due neither to a reduction…
An anti-inflammatory ditriazine inhibiting leukocyte functions and expression of inducible nitric oxide synthase and cyclo-oxygenase-2.
2000
A ditriazine derivative (4,10-dichloropyrido[5,6:4,5]thieno[3,2-d':3, 2-d]-1,2,3-ditriazine (DTD)) inhibited neutrophil functions, including degranulation, superoxide generation, and leukotriene B(4) production, without any effect on 5-lipoxygenase activity. This compound reduced nitric oxide (NO) and prostaglandin E(2) production in mouse peritoneal macrophages stimulated with lipopolysaccharide, whereas no influence on the activity of inducible NO synthase, cyclo-oxygenase-2 or cyclo-oxygenase-1 was observed. DTD significantly reduced mouse paw oedema induced by carrageenan and also markedly reduced NO and prostaglandin E(2) levels in exudates from 24-h zymosan-stimulated mouse air pouch.…
Anti-inflammatory activity of berenjenol and related compounds.
2008
Berenjenol ( 1), isolated from OXANDRA cf. XYLOPIOIDES (Annonaceae), was tested on two different experimental models of inflammation. The compound showed anti-inflammatory activity in the test of acute mouse ear edema induced by TPA (54 % inhibition, 1 μmol/ear) as well as in the test of subchronic inflammation induced by repeated application of TPA (57 % inhibition, 7 × 1 μmol/ear). Moreover, while it reduced the expression of both COX-2 (65 % inhibition at 50 μM) and iNOS (80 % inhibition at 50 μM), it was not active against TNF- α and IL-1 β in murine macrophages (RAW 264.7) stimulated with LPS. Structural modification of 1 gave two derivatives, berenjenol acetate ( 2) and 3-oxo-berenjen…