Search results for "ACTIVATION"

Apoptosis induced in vascular smooth muscle cells by oxidative stress is partly prevented by pretreatment with CGRP.

2003

Activation of MAP kinase signaling pathway in the mussel Mytilus galloprovincialis as biomarker of environmental pollution

2010

Stimulation of MAP kinase signal transduction pathway by various stressful stimuli was investigated in the marine bivalve Mytilus galloprovincialis. Analyses were performed in animals exposed in laboratory to selected pollutants and in mussels collected in winter and summer along the eastern Adriatic coast (Croatia). Effects of oxidative stress, induced by tributyltin, hydrogen peroxide and water soluble fraction of diesel fuel on the activation/phosphorylation of the three Mitogen-Activated Protein Kinases (MAPKs) p38, JNK and ERK using a newly developed ELISA procedure were evaluated. MAP kinase activation was analyzed 1 h after exposure of mussels to chemical agents, and after recovery p…

Inverted energy gap law for the nonradiative decay in fluorescent floppy molecules: larger fluorescence quantum yields for smaller energy gaps

2019

A data survey on experimental fluorescence quantum yields of (multi)substituted dicyano-distyrylbenzenes in fluid solution evidences that non-radiative decay increases with the Franck-Condon energy (E-FC), being opposite to the conventional energy gap law. Quantum-chemistry indicates that this is controlled by access to the conical intersection (CI) following the Bell-Evans-Polanyi principle as a first-step approximation for this family of molecules; the variations in E-FC among the different compounds are found to be decisive, while those of E-CI are estimated to be weaker or even enhancing the effect. The current findings may have significant consequences for the design of molecules for o…

The three-dimensional structure of Drosophila melanogaster (6–4) photolyase at room temperature

2021

A crystal structure of a photolyase at room temperature confirms the structural information obtained from cryogenic crystallography and paves the way for time-resolved studies of the photolyase at an X-ray free-electron laser.

Trefoil factor TFF1-induced protection of conjunctival cells from apoptosis at premitochondrial and postmitochondrial levels.

2008

PURPOSE. Goblet cells of the conjunctival epithelium synthesize and secrete TFF1 (Trefoil factor 1), a small protease-resistant peptide that, together with mucins, is responsible for the rheologic properties of the tear film. This study aimed to determine whether TFF1, whose synthesis increases in inflammatory conditions such as pterygium, could protect conjunctival cells from apoptosis. METHODS. Chang conjunctival cells, either wild-type or expressing TFF1 through stable transfection, were exposed to benzalkonium chloride (BAK) and ultraviolet (UV) irradiation to trigger apoptosis. The authors used cell fractionation to detect lipid raft‐associated proteins, coimmunoprecipitation to explor…

CD4+CD25+ regulatory T cells inhibit natural killer cell functions in a transforming growth factor-beta-dependent manner.

2007

Tumor growth promotes the expansion of CD4+CD25+ regulatory T (T reg) cells that counteract T cell–mediated immune responses. An inverse correlation between natural killer (NK) cell activation and T reg cell expansion in tumor-bearing patients, shown here, prompted us to address the role of T reg cells in controlling innate antitumor immunity. Our experiments indicate that human T reg cells expressed membrane-bound transforming growth factor (TGF)–β, which directly inhibited NK cell effector functions and down-regulated NKG2D receptors on the NK cell surface. Adoptive transfer of wild-type T reg cells but not TGF-β−/− T reg cells into nude mice suppressed NK cell–mediated cytotoxicity, redu…

Differential inhibition of TRAIL-mediated DR5-DISC formation by decoy receptors 1 and 2.

2006

International audience; Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF family that induces cancer cell death by apoptosis with some selectivity. TRAIL-induced apoptosis is mediated by the transmembrane receptors death receptor 4 (DR4) (also known as TRAIL-R1) and DR5 (TRAIL-R2). TRAIL can also bind decoy receptor 1 (DcR1) (TRAIL-R3) and DcR2 (TRAIL-R4) that fail to induce apoptosis since they lack and have a truncated cytoplasmic death domain, respectively. In addition, DcR1 and DcR2 inhibit DR4- and DR5-mediated, TRAIL-induced apoptosis and we demonstrate here that this occurs through distinct mechanisms. While DcR1 prevents the assembly of the…

A functional analysis of ACP-20, an adult-specific cuticular protein gene from the beetle Tenebrio. Role of an intronic sequence in transcriptional a…

2004

0962-1075 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; A gene encoding the adult cuticular protein ACP-20 was isolated in Tenebrio. It consists of three exons interspersed by two introns, intron 1 interrupting the signal peptide. To understand the regulatory mechanisms of ACP-20 expression, ACP-20 promoter-luciferase reporter gene constructs were transfected into cultured pharate adult wing epidermis. Transfection assays needed the presence of 20-hydroxyecdysone, confirming that ACP-20 is up-regulated by ecdysteroids. Analysis of 5' deletion constructs revealed that three regions are necessary for high levels of transcription. Interaction experiments between i…

Modulation of MHC Class II Determinants on Rat Langerhans Cells During Short Term Culture

1993

Epidermal Langerhans cells (LC) are regarded as the most peripheral outpost of the immune system. They play a pivotal role during the onset of an immune response in the skin. One of the principal functions of LC is reflected in their extraordinary potency to present antigen to high activation requiring naive T cells.

Major histocompatibility complex class I-restricted activation of cloned T cells by a soluble protein in the absence of accessory cells.

1989

A T-cell clone, 10BK.1, was established from the draining lymph nodes of (B10 x B10.BR)F1 mice immunized with ovalbumin (OVA) according to standard protocols. Upon coculture with the antigen, 10BK.1 cells reacted by production of lymphokines and by proliferation despite the absence of additional antigen-presenting cells. These T cells do not express major histocompatibility complex (MHC) class II molecules on the cell surface as assessed on the basis of several criteria: by cytofluorometric analysis I-A and I-E determinants were not detectable; 10BK.1 cells could not act as antigen-presenting cells for long-term-cultured MHC class II-restricted T-cell clones; and monoclonal antibodies direc…